diff mbox series

[v10,04/11] Move malloc hooks into a compat DSO

Message ID 20210719184637.1225275-5-siddhesh@sourceware.org
State Committed
Commit 2d2d9f2b48a943fa556301db532103d09800da4d
Headers show
Series malloc hooks removal | expand

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Context Check Description
dj/TryBot-apply_patch success Patch applied to master at the time it was sent

Commit Message

Siddhesh Poyarekar July 19, 2021, 6:46 p.m. UTC
Remove all malloc hook uses from core malloc functions and move it
into a new library libc_malloc_debug.so.  With this, the hooks now no
longer have any effect on the core library.

libc_malloc_debug.so is a malloc interposer that needs to be preloaded
to get hooks functionality back so that the debugging features that
depend on the hooks, i.e. malloc-check, mcheck and mtrace work again.
Without the preloaded DSO these debugging features will be nops.
These features will be ported away from hooks in subsequent patches.

Similarly, legacy applications that need hooks functionality need to
preload libc_malloc_debug.so.

The symbols exported by libc_malloc_debug.so are maintained at exactly
the same version as libc.so.

Finally, static binaries will no longer be able to use malloc
debugging features since they cannot preload the debugging DSO.
---
 NEWS                                          |   6 +
 Rules                                         |   9 +-
 catgets/Makefile                              |   4 +-
 elf/Makefile                                  |  15 +-
 elf/tst-leaks1-static.c                       |   1 -
 iconvdata/Makefile                            |   3 +-
 intl/tst-gettext.sh                           |   1 +
 libio/Makefile                                |  12 +-
 localedata/Makefile                           |   3 +-
 malloc/Makefile                               |  47 +++--
 malloc/Versions                               |  20 ++
 malloc/arena.c                                |   7 -
 malloc/hooks.c                                |  64 +++++-
 malloc/malloc-debug.c                         | 189 ++++++++++++++++++
 malloc/malloc.c                               |  85 ++------
 malloc/mcheck.c                               |   1 +
 malloc/mtrace.c                               |   1 +
 malloc/tst-compathooks-off.c                  | 145 ++++++++++++++
 malloc/tst-compathooks-on.c                   |   2 +
 malloc/tst-malloc-usable-static-tunables.c    |   1 -
 malloc/tst-malloc-usable-static.c             |   1 -
 malloc/tst-mtrace.sh                          |   1 +
 manual/memory.texi                            |  16 +-
 manual/tunables.texi                          |   4 +-
 misc/Makefile                                 |   6 +-
 nptl/Makefile                                 |   3 +-
 posix/Makefile                                |  40 ++--
 resolv/Makefile                               |   9 +-
 shlib-versions                                |   3 +
 stdio-common/Makefile                         |  15 +-
 sysdeps/generic/libc_malloc_debug.abilist     |   0
 sysdeps/mach/hurd/Makefile                    |   1 +
 .../mach/hurd/i386/libc_malloc_debug.abilist  |   9 +
 sysdeps/pthread/Makefile                      |   3 +-
 .../linux/aarch64/libc_malloc_debug.abilist   |   9 +
 .../linux/alpha/libc_malloc_debug.abilist     |   9 +
 .../sysv/linux/arc/libc_malloc_debug.abilist  |   9 +
 .../linux/arm/be/libc_malloc_debug.abilist    |   9 +
 .../linux/arm/le/libc_malloc_debug.abilist    |   9 +
 .../sysv/linux/csky/libc_malloc_debug.abilist |   9 +
 .../sysv/linux/hppa/libc_malloc_debug.abilist |   9 +
 sysdeps/unix/sysv/linux/hppa/shlib-versions   |   2 +
 .../sysv/linux/i386/libc_malloc_debug.abilist |   9 +
 .../sysv/linux/ia64/libc_malloc_debug.abilist |   9 +
 sysdeps/unix/sysv/linux/ia64/shlib-versions   |   2 +
 .../m68k/coldfire/libc_malloc_debug.abilist   |   9 +
 .../m68k/m680x0/libc_malloc_debug.abilist     |   9 +
 .../microblaze/be/libc_malloc_debug.abilist   |   9 +
 .../microblaze/le/libc_malloc_debug.abilist   |   9 +
 .../mips/mips32/fpu/libc_malloc_debug.abilist |   9 +
 .../mips32/nofpu/libc_malloc_debug.abilist    |   9 +
 .../mips/mips64/n32/libc_malloc_debug.abilist |   9 +
 .../mips/mips64/n64/libc_malloc_debug.abilist |   9 +
 sysdeps/unix/sysv/linux/mips/shlib-versions   |   2 +
 .../linux/nios2/libc_malloc_debug.abilist     |   9 +
 .../powerpc32/fpu/libc_malloc_debug.abilist   |   9 +
 .../powerpc32/nofpu/libc_malloc_debug.abilist |   9 +
 .../powerpc64/be/libc_malloc_debug.abilist    |   9 +
 .../powerpc64/le/libc_malloc_debug.abilist    |   9 +
 .../riscv/rv32/libc_malloc_debug.abilist      |   9 +
 .../riscv/rv64/libc_malloc_debug.abilist      |   9 +
 .../s390/s390-32/libc_malloc_debug.abilist    |   9 +
 .../s390/s390-64/libc_malloc_debug.abilist    |   9 +
 .../linux/sh/be/libc_malloc_debug.abilist     |   9 +
 .../linux/sh/le/libc_malloc_debug.abilist     |   9 +
 sysdeps/unix/sysv/linux/sh/shlib-versions     |   1 +
 .../sparc/sparc32/libc_malloc_debug.abilist   |   9 +
 .../sparc/sparc64/libc_malloc_debug.abilist   |   9 +
 .../sysv/linux/sparc/sparc64/shlib-versions   |   1 +
 .../linux/x86_64/64/libc_malloc_debug.abilist |   9 +
 .../x86_64/x32/libc_malloc_debug.abilist      |   9 +
 71 files changed, 865 insertions(+), 158 deletions(-)
 delete mode 100644 elf/tst-leaks1-static.c
 create mode 100644 malloc/malloc-debug.c
 create mode 100644 malloc/tst-compathooks-off.c
 create mode 100644 malloc/tst-compathooks-on.c
 delete mode 100644 malloc/tst-malloc-usable-static-tunables.c
 delete mode 100644 malloc/tst-malloc-usable-static.c
 create mode 100644 sysdeps/generic/libc_malloc_debug.abilist
 create mode 100644 sysdeps/mach/hurd/i386/libc_malloc_debug.abilist
 create mode 100644 sysdeps/unix/sysv/linux/aarch64/libc_malloc_debug.abilist
 create mode 100644 sysdeps/unix/sysv/linux/alpha/libc_malloc_debug.abilist
 create mode 100644 sysdeps/unix/sysv/linux/arc/libc_malloc_debug.abilist
 create mode 100644 sysdeps/unix/sysv/linux/arm/be/libc_malloc_debug.abilist
 create mode 100644 sysdeps/unix/sysv/linux/arm/le/libc_malloc_debug.abilist
 create mode 100644 sysdeps/unix/sysv/linux/csky/libc_malloc_debug.abilist
 create mode 100644 sysdeps/unix/sysv/linux/hppa/libc_malloc_debug.abilist
 create mode 100644 sysdeps/unix/sysv/linux/i386/libc_malloc_debug.abilist
 create mode 100644 sysdeps/unix/sysv/linux/ia64/libc_malloc_debug.abilist
 create mode 100644 sysdeps/unix/sysv/linux/m68k/coldfire/libc_malloc_debug.abilist
 create mode 100644 sysdeps/unix/sysv/linux/m68k/m680x0/libc_malloc_debug.abilist
 create mode 100644 sysdeps/unix/sysv/linux/microblaze/be/libc_malloc_debug.abilist
 create mode 100644 sysdeps/unix/sysv/linux/microblaze/le/libc_malloc_debug.abilist
 create mode 100644 sysdeps/unix/sysv/linux/mips/mips32/fpu/libc_malloc_debug.abilist
 create mode 100644 sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc_malloc_debug.abilist
 create mode 100644 sysdeps/unix/sysv/linux/mips/mips64/n32/libc_malloc_debug.abilist
 create mode 100644 sysdeps/unix/sysv/linux/mips/mips64/n64/libc_malloc_debug.abilist
 create mode 100644 sysdeps/unix/sysv/linux/nios2/libc_malloc_debug.abilist
 create mode 100644 sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc_malloc_debug.abilist
 create mode 100644 sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc_malloc_debug.abilist
 create mode 100644 sysdeps/unix/sysv/linux/powerpc/powerpc64/be/libc_malloc_debug.abilist
 create mode 100644 sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libc_malloc_debug.abilist
 create mode 100644 sysdeps/unix/sysv/linux/riscv/rv32/libc_malloc_debug.abilist
 create mode 100644 sysdeps/unix/sysv/linux/riscv/rv64/libc_malloc_debug.abilist
 create mode 100644 sysdeps/unix/sysv/linux/s390/s390-32/libc_malloc_debug.abilist
 create mode 100644 sysdeps/unix/sysv/linux/s390/s390-64/libc_malloc_debug.abilist
 create mode 100644 sysdeps/unix/sysv/linux/sh/be/libc_malloc_debug.abilist
 create mode 100644 sysdeps/unix/sysv/linux/sh/le/libc_malloc_debug.abilist
 create mode 100644 sysdeps/unix/sysv/linux/sparc/sparc32/libc_malloc_debug.abilist
 create mode 100644 sysdeps/unix/sysv/linux/sparc/sparc64/libc_malloc_debug.abilist
 create mode 100644 sysdeps/unix/sysv/linux/x86_64/64/libc_malloc_debug.abilist
 create mode 100644 sysdeps/unix/sysv/linux/x86_64/x32/libc_malloc_debug.abilist

Comments

Carlos O'Donell July 22, 2021, 12:25 p.m. UTC | #1
On 7/19/21 2:46 PM, Siddhesh Poyarekar wrote:
> Remove all malloc hook uses from core malloc functions and move it
> into a new library libc_malloc_debug.so.  With this, the hooks now no
> longer have any effect on the core library.
> 
> libc_malloc_debug.so is a malloc interposer that needs to be preloaded
> to get hooks functionality back so that the debugging features that
> depend on the hooks, i.e. malloc-check, mcheck and mtrace work again.
> Without the preloaded DSO these debugging features will be nops.
> These features will be ported away from hooks in subsequent patches.
> 
> Similarly, legacy applications that need hooks functionality need to
> preload libc_malloc_debug.so.
> 
> The symbols exported by libc_malloc_debug.so are maintained at exactly
> the same version as libc.so.
> 
> Finally, static binaries will no longer be able to use malloc
> debugging features since they cannot preload the debugging DSO.

We agreed reallocarray should not be moved since it should use realloc
under the hood and we should not require new malloc inteposers to use it.

OK for 2.34.

Tested without regression for x86_64 and i686.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>

> ---
>  NEWS                                          |   6 +
>  Rules                                         |   9 +-
>  catgets/Makefile                              |   4 +-
>  elf/Makefile                                  |  15 +-
>  elf/tst-leaks1-static.c                       |   1 -
>  iconvdata/Makefile                            |   3 +-
>  intl/tst-gettext.sh                           |   1 +
>  libio/Makefile                                |  12 +-
>  localedata/Makefile                           |   3 +-
>  malloc/Makefile                               |  47 +++--
>  malloc/Versions                               |  20 ++
>  malloc/arena.c                                |   7 -
>  malloc/hooks.c                                |  64 +++++-
>  malloc/malloc-debug.c                         | 189 ++++++++++++++++++
>  malloc/malloc.c                               |  85 ++------
>  malloc/mcheck.c                               |   1 +
>  malloc/mtrace.c                               |   1 +
>  malloc/tst-compathooks-off.c                  | 145 ++++++++++++++
>  malloc/tst-compathooks-on.c                   |   2 +
>  malloc/tst-malloc-usable-static-tunables.c    |   1 -
>  malloc/tst-malloc-usable-static.c             |   1 -
>  malloc/tst-mtrace.sh                          |   1 +
>  manual/memory.texi                            |  16 +-
>  manual/tunables.texi                          |   4 +-
>  misc/Makefile                                 |   6 +-
>  nptl/Makefile                                 |   3 +-
>  posix/Makefile                                |  40 ++--
>  resolv/Makefile                               |   9 +-
>  shlib-versions                                |   3 +
>  stdio-common/Makefile                         |  15 +-
>  sysdeps/generic/libc_malloc_debug.abilist     |   0
>  sysdeps/mach/hurd/Makefile                    |   1 +
>  .../mach/hurd/i386/libc_malloc_debug.abilist  |   9 +
>  sysdeps/pthread/Makefile                      |   3 +-
>  .../linux/aarch64/libc_malloc_debug.abilist   |   9 +
>  .../linux/alpha/libc_malloc_debug.abilist     |   9 +
>  .../sysv/linux/arc/libc_malloc_debug.abilist  |   9 +
>  .../linux/arm/be/libc_malloc_debug.abilist    |   9 +
>  .../linux/arm/le/libc_malloc_debug.abilist    |   9 +
>  .../sysv/linux/csky/libc_malloc_debug.abilist |   9 +
>  .../sysv/linux/hppa/libc_malloc_debug.abilist |   9 +
>  sysdeps/unix/sysv/linux/hppa/shlib-versions   |   2 +
>  .../sysv/linux/i386/libc_malloc_debug.abilist |   9 +
>  .../sysv/linux/ia64/libc_malloc_debug.abilist |   9 +
>  sysdeps/unix/sysv/linux/ia64/shlib-versions   |   2 +
>  .../m68k/coldfire/libc_malloc_debug.abilist   |   9 +
>  .../m68k/m680x0/libc_malloc_debug.abilist     |   9 +
>  .../microblaze/be/libc_malloc_debug.abilist   |   9 +
>  .../microblaze/le/libc_malloc_debug.abilist   |   9 +
>  .../mips/mips32/fpu/libc_malloc_debug.abilist |   9 +
>  .../mips32/nofpu/libc_malloc_debug.abilist    |   9 +
>  .../mips/mips64/n32/libc_malloc_debug.abilist |   9 +
>  .../mips/mips64/n64/libc_malloc_debug.abilist |   9 +
>  sysdeps/unix/sysv/linux/mips/shlib-versions   |   2 +
>  .../linux/nios2/libc_malloc_debug.abilist     |   9 +
>  .../powerpc32/fpu/libc_malloc_debug.abilist   |   9 +
>  .../powerpc32/nofpu/libc_malloc_debug.abilist |   9 +
>  .../powerpc64/be/libc_malloc_debug.abilist    |   9 +
>  .../powerpc64/le/libc_malloc_debug.abilist    |   9 +
>  .../riscv/rv32/libc_malloc_debug.abilist      |   9 +
>  .../riscv/rv64/libc_malloc_debug.abilist      |   9 +
>  .../s390/s390-32/libc_malloc_debug.abilist    |   9 +
>  .../s390/s390-64/libc_malloc_debug.abilist    |   9 +
>  .../linux/sh/be/libc_malloc_debug.abilist     |   9 +
>  .../linux/sh/le/libc_malloc_debug.abilist     |   9 +
>  sysdeps/unix/sysv/linux/sh/shlib-versions     |   1 +
>  .../sparc/sparc32/libc_malloc_debug.abilist   |   9 +
>  .../sparc/sparc64/libc_malloc_debug.abilist   |   9 +
>  .../sysv/linux/sparc/sparc64/shlib-versions   |   1 +
>  .../linux/x86_64/64/libc_malloc_debug.abilist |   9 +
>  .../x86_64/x32/libc_malloc_debug.abilist      |   9 +
>  71 files changed, 865 insertions(+), 158 deletions(-)
>  delete mode 100644 elf/tst-leaks1-static.c
>  create mode 100644 malloc/malloc-debug.c
>  create mode 100644 malloc/tst-compathooks-off.c
>  create mode 100644 malloc/tst-compathooks-on.c
>  delete mode 100644 malloc/tst-malloc-usable-static-tunables.c
>  delete mode 100644 malloc/tst-malloc-usable-static.c
>  create mode 100644 sysdeps/generic/libc_malloc_debug.abilist
>  create mode 100644 sysdeps/mach/hurd/i386/libc_malloc_debug.abilist
>  create mode 100644 sysdeps/unix/sysv/linux/aarch64/libc_malloc_debug.abilist
>  create mode 100644 sysdeps/unix/sysv/linux/alpha/libc_malloc_debug.abilist
>  create mode 100644 sysdeps/unix/sysv/linux/arc/libc_malloc_debug.abilist
>  create mode 100644 sysdeps/unix/sysv/linux/arm/be/libc_malloc_debug.abilist
>  create mode 100644 sysdeps/unix/sysv/linux/arm/le/libc_malloc_debug.abilist
>  create mode 100644 sysdeps/unix/sysv/linux/csky/libc_malloc_debug.abilist
>  create mode 100644 sysdeps/unix/sysv/linux/hppa/libc_malloc_debug.abilist
>  create mode 100644 sysdeps/unix/sysv/linux/i386/libc_malloc_debug.abilist
>  create mode 100644 sysdeps/unix/sysv/linux/ia64/libc_malloc_debug.abilist
>  create mode 100644 sysdeps/unix/sysv/linux/m68k/coldfire/libc_malloc_debug.abilist
>  create mode 100644 sysdeps/unix/sysv/linux/m68k/m680x0/libc_malloc_debug.abilist
>  create mode 100644 sysdeps/unix/sysv/linux/microblaze/be/libc_malloc_debug.abilist
>  create mode 100644 sysdeps/unix/sysv/linux/microblaze/le/libc_malloc_debug.abilist
>  create mode 100644 sysdeps/unix/sysv/linux/mips/mips32/fpu/libc_malloc_debug.abilist
>  create mode 100644 sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc_malloc_debug.abilist
>  create mode 100644 sysdeps/unix/sysv/linux/mips/mips64/n32/libc_malloc_debug.abilist
>  create mode 100644 sysdeps/unix/sysv/linux/mips/mips64/n64/libc_malloc_debug.abilist
>  create mode 100644 sysdeps/unix/sysv/linux/nios2/libc_malloc_debug.abilist
>  create mode 100644 sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc_malloc_debug.abilist
>  create mode 100644 sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc_malloc_debug.abilist
>  create mode 100644 sysdeps/unix/sysv/linux/powerpc/powerpc64/be/libc_malloc_debug.abilist
>  create mode 100644 sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libc_malloc_debug.abilist
>  create mode 100644 sysdeps/unix/sysv/linux/riscv/rv32/libc_malloc_debug.abilist
>  create mode 100644 sysdeps/unix/sysv/linux/riscv/rv64/libc_malloc_debug.abilist
>  create mode 100644 sysdeps/unix/sysv/linux/s390/s390-32/libc_malloc_debug.abilist
>  create mode 100644 sysdeps/unix/sysv/linux/s390/s390-64/libc_malloc_debug.abilist
>  create mode 100644 sysdeps/unix/sysv/linux/sh/be/libc_malloc_debug.abilist
>  create mode 100644 sysdeps/unix/sysv/linux/sh/le/libc_malloc_debug.abilist
>  create mode 100644 sysdeps/unix/sysv/linux/sparc/sparc32/libc_malloc_debug.abilist
>  create mode 100644 sysdeps/unix/sysv/linux/sparc/sparc64/libc_malloc_debug.abilist
>  create mode 100644 sysdeps/unix/sysv/linux/x86_64/64/libc_malloc_debug.abilist
>  create mode 100644 sysdeps/unix/sysv/linux/x86_64/x32/libc_malloc_debug.abilist
> 
> diff --git a/NEWS b/NEWS
> index 75ad8a9b95..fa80c9685b 100644
> --- a/NEWS
> +++ b/NEWS
> @@ -132,6 +132,12 @@ Deprecated and removed features, and other changes affecting compatibility:
>    applications will continue to link against these symbols but the interfaces
>    no longer have any effect on malloc.
>  
> +* Debugging features in malloc such as the MALLOC_CHECK_ environment variable
> +  (or the glibc.malloc.check tunable), mtrace() and mcheck() have now been
> +  disabled by default in the main C library.  Users looking to use these
> +  features now need to preload a new debugging DSO libc_malloc_debug.so to get
> +  this functionality back.
> +
>  Changes to build and runtime requirements:
>  
>  * On Linux, the shm_open, sem_open, and related functions now expect the
> diff --git a/Rules b/Rules
> index ba13598df6..b1137afe71 100644
> --- a/Rules
> +++ b/Rules
> @@ -279,10 +279,17 @@ endif
>  
>  # All malloc-check tests will be run with MALLOC_CHECK_=3
>  define malloc-check-ENVS
> -$(1)-malloc-check-ENV = MALLOC_CHECK_=3
> +$(1)-malloc-check-ENV = MALLOC_CHECK_=3 \
> +			LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
>  endef
>  $(foreach t,$(tests-malloc-check),$(eval $(call malloc-check-ENVS,$(t))))
>  
> +# mcheck tests need the debug DSO to support -lmcheck.
> +define mcheck-ENVS
> +$(1)-mcheck-ENV = LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
> +endef
> +$(foreach t,$(tests-mcheck),$(eval $(call mcheck-ENVS,$(t))))
> +
>  ifneq "$(strip $(tests) $(tests-internal) $(xtests) $(test-srcs))" ""
>  # These are the implicit rules for making test outputs
>  # from the test programs and whatever input files are present.
> diff --git a/catgets/Makefile b/catgets/Makefile
> index 54da9a985f..215965b352 100644
> --- a/catgets/Makefile
> +++ b/catgets/Makefile
> @@ -56,7 +56,9 @@ generated += tst-catgets.mtrace tst-catgets-mem.out
>  
>  generated-dirs += de
>  
> -tst-catgets-ENV = NLSPATH="$(objpfx)%l/%N.cat" LANG=de MALLOC_TRACE=$(objpfx)tst-catgets.mtrace
> +tst-catgets-ENV = NLSPATH="$(objpfx)%l/%N.cat" LANG=de \
> +		  MALLOC_TRACE=$(objpfx)tst-catgets.mtrace \
> +		  LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
>  
>  ifeq ($(run-built-tests),yes)
>  # This test just checks whether the program produces any error or not.
> diff --git a/elf/Makefile b/elf/Makefile
> index 4fe60947ad..87a70d6c7a 100644
> --- a/elf/Makefile
> +++ b/elf/Makefile
> @@ -156,7 +156,7 @@ $(inst_auditdir)/sotruss-lib.so: $(objpfx)sotruss-lib.so $(+force)
>  	$(do-install-program)
>  endif
>  
> -tests-static-normal := tst-leaks1-static tst-array1-static tst-array5-static \
> +tests-static-normal := tst-array1-static tst-array5-static \
>  	       tst-dl-iter-static \
>  	       tst-tlsalign-static tst-tlsalign-extern-static \
>  	       tst-linkall-static tst-env-setuid tst-env-setuid-tunables \
> @@ -242,7 +242,7 @@ endif
>  tests += $(tests-execstack-$(have-z-execstack))
>  ifeq ($(run-built-tests),yes)
>  tests-special += $(objpfx)tst-leaks1-mem.out \
> -		 $(objpfx)tst-leaks1-static-mem.out $(objpfx)noload-mem.out \
> +		 $(objpfx)noload-mem.out \
>  		 $(objpfx)tst-ldconfig-X.out $(objpfx)tst-rtld-help.out
>  endif
>  tlsmod17a-suffixes = 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
> @@ -904,7 +904,8 @@ $(objpfx)noload.out: $(objpfx)testobj5.so
>  $(objpfx)noload-mem.out: $(objpfx)noload.out
>  	$(common-objpfx)malloc/mtrace $(objpfx)noload.mtrace > $@; \
>  	$(evaluate-test)
> -noload-ENV = MALLOC_TRACE=$(objpfx)noload.mtrace
> +noload-ENV = MALLOC_TRACE=$(objpfx)noload.mtrace \
> +	     LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
>  
>  LDFLAGS-nodelete = -rdynamic
>  LDFLAGS-nodelmod1.so = -Wl,--enable-new-dtags,-z,nodelete
> @@ -1282,12 +1283,8 @@ $(objpfx)tst-leaks1-mem.out: $(objpfx)tst-leaks1.out
>  	$(common-objpfx)malloc/mtrace $(objpfx)tst-leaks1.mtrace > $@; \
>  	$(evaluate-test)
>  
> -$(objpfx)tst-leaks1-static-mem.out: $(objpfx)tst-leaks1-static.out
> -	$(common-objpfx)malloc/mtrace $(objpfx)tst-leaks1-static.mtrace > $@; \
> -	$(evaluate-test)
> -
> -tst-leaks1-ENV = MALLOC_TRACE=$(objpfx)tst-leaks1.mtrace
> -tst-leaks1-static-ENV = MALLOC_TRACE=$(objpfx)tst-leaks1-static.mtrace
> +tst-leaks1-ENV = MALLOC_TRACE=$(objpfx)tst-leaks1.mtrace \
> +		 LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
>  
>  $(objpfx)tst-thrlock: $(shared-thread-library)
>  $(objpfx)tst-thrlock.out: $(libm)
> diff --git a/elf/tst-leaks1-static.c b/elf/tst-leaks1-static.c
> deleted file mode 100644
> index b956d66905..0000000000
> --- a/elf/tst-leaks1-static.c
> +++ /dev/null
> @@ -1 +0,0 @@
> -#include "tst-leaks1.c"
> diff --git a/iconvdata/Makefile b/iconvdata/Makefile
> index bb3f621b49..c216f959df 100644
> --- a/iconvdata/Makefile
> +++ b/iconvdata/Makefile
> @@ -301,7 +301,8 @@ cpp-srcs-left := $(modules) $(generated-modules) $(libJIS-routines) \
>  lib := iconvdata
>  include $(patsubst %,$(..)libof-iterator.mk,$(cpp-srcs-left))
>  
> -tst-loading-ENV = MALLOC_TRACE=$(objpfx)tst-loading.mtrace
> +tst-loading-ENV = MALLOC_TRACE=$(objpfx)tst-loading.mtrace \
> +		  LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
>  $(objpfx)mtrace-tst-loading.out: $(objpfx)tst-loading.out
>  	$(common-objpfx)malloc/mtrace $(objpfx)tst-loading.mtrace > $@; \
>  	$(evaluate-test)
> diff --git a/intl/tst-gettext.sh b/intl/tst-gettext.sh
> index 77864de18c..37d9fcb80a 100755
> --- a/intl/tst-gettext.sh
> +++ b/intl/tst-gettext.sh
> @@ -50,6 +50,7 @@ msgfmt -o ${objpfx}domaindir/existing-locale/LC_TIME/existing-time-domain.mo \
>  ${test_program_prefix_before_env} \
>  ${run_program_env} \
>  MALLOC_TRACE=$malloc_trace \
> +LD_PRELOAD=${common_objpfx}malloc/libc_malloc_debug.so \
>  LOCPATH=${objpfx}localedir:${common_objpfx}localedata \
>  ${test_program_prefix_after_env} \
>  ${objpfx}tst-gettext > ${objpfx}tst-gettext.out ${objpfx}domaindir
> diff --git a/libio/Makefile b/libio/Makefile
> index 73f731e064..5336b7d595 100644
> --- a/libio/Makefile
> +++ b/libio/Makefile
> @@ -165,10 +165,14 @@ LDFLAGS-tst-bz24228 = -Wl,--version-script=tst-bz24228.map
>  
>  tst_wprintf2-ARGS = "Some Text"
>  
> -test-fmemopen-ENV = MALLOC_TRACE=$(objpfx)test-fmemopen.mtrace
> -tst-fopenloc-ENV = MALLOC_TRACE=$(objpfx)tst-fopenloc.mtrace
> -tst-bz22415-ENV = MALLOC_TRACE=$(objpfx)tst-bz22415.mtrace
> -tst-bz24228-ENV = MALLOC_TRACE=$(objpfx)tst-bz24228.mtrace
> +test-fmemopen-ENV = MALLOC_TRACE=$(objpfx)test-fmemopen.mtrace \
> +		    LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
> +tst-fopenloc-ENV = MALLOC_TRACE=$(objpfx)tst-fopenloc.mtrace \
> +		   LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
> +tst-bz22415-ENV = MALLOC_TRACE=$(objpfx)tst-bz22415.mtrace \
> +		  LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
> +tst-bz24228-ENV = MALLOC_TRACE=$(objpfx)tst-bz24228.mtrace \
> +		  LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
>  
>  generated += test-fmemopen.mtrace test-fmemopen.check
>  generated += tst-fopenloc.mtrace tst-fopenloc.check
> diff --git a/localedata/Makefile b/localedata/Makefile
> index 14e04cd3c5..f585e0dd41 100644
> --- a/localedata/Makefile
> +++ b/localedata/Makefile
> @@ -456,7 +456,8 @@ $(INSTALL-SUPPORTED-LOCALE-FILES): install-locales-dir
>  tst-setlocale-ENV = LC_ALL=ja_JP.EUC-JP
>  tst-wctype-ENV = LC_ALL=ja_JP.EUC-JP
>  
> -tst-leaks-ENV = MALLOC_TRACE=$(objpfx)tst-leaks.mtrace
> +tst-leaks-ENV = MALLOC_TRACE=$(objpfx)tst-leaks.mtrace \
> +		LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
>  $(objpfx)mtrace-tst-leaks.out: $(objpfx)tst-leaks.out
>  	$(common-objpfx)malloc/mtrace $(objpfx)tst-leaks.mtrace > $@; \
>  	$(evaluate-test)
> diff --git a/malloc/Makefile b/malloc/Makefile
> index ef5b485ffb..89d27d482f 100644
> --- a/malloc/Makefile
> +++ b/malloc/Makefile
> @@ -46,12 +46,11 @@ tests := mallocbug tst-malloc tst-valloc tst-calloc tst-obstack \
>  
>  tests-static := \
>  	 tst-interpose-static-nothread \
> -	 tst-interpose-static-thread \
> -	 tst-malloc-usable-static \
> +	 tst-interpose-static-thread
>  
>  # Test for the malloc_set_state symbol removed in glibc 2.25.
> -ifeq ($(have-GLIBC_2.24)$(build-shared),yesyes)
> -tests += tst-mallocstate
> +ifeq ($(have-GLIBC_2.23)$(build-shared),yesyes)
> +tests += tst-mallocstate tst-compathooks-off tst-compathooks-on
>  endif
>  
>  tests-internal := tst-scratch_buffer
> @@ -64,7 +63,6 @@ tests-internal += \
>  
>  ifneq (no,$(have-tunables))
>  tests += tst-malloc-usable-tunables tst-mxfast
> -tests-static += tst-malloc-usable-static-tunables
>  endif
>  
>  tests += $(tests-static)
> @@ -73,7 +71,8 @@ test-srcs = tst-mtrace
>  # These tests either are run with MALLOC_CHECK_=3 by default or do not work
>  # with MALLOC_CHECK_=3 because they expect a specific failure.
>  tests-exclude-malloc-check = tst-malloc-check tst-malloc-usable \
> -	tst-mxfast tst-safe-linking
> +	tst-mxfast tst-safe-linking \
> +	tst-compathooks-off tst-compathooks-on
>  
>  # Run all tests with MALLOC_CHECK_=3
>  tests-malloc-check = $(filter-out $(tests-exclude-malloc-check),$(tests))
> @@ -91,15 +90,14 @@ tests-exclude-mcheck = tst-mallocstate \
>  	tst-malloc-tcache-leak \
>  	tst-malloc-thread-exit \
>  	tst-malloc-thread-fail \
> -	tst-malloc-usable-static \
> -	tst-malloc-usable-static-tunables \
>  	tst-malloc-usable-tunables \
>  	tst-malloc_info \
>  	tst-memalign \
>  	tst-posix_memalign \
>  	tst-realloc \
>  	tst-pvalloc-fortify \
> -	tst-reallocarray
> +	tst-reallocarray \
> +	tst-compathooks-off tst-compathooks-on
>  
>  tests-mcheck = $(filter-out $(tests-exclude-mcheck), $(tests))
>  endif
> @@ -122,8 +120,8 @@ routines = malloc mcheck mtrace obstack reallocarray \
>  install-lib := libmcheck.a
>  non-lib.a := libmcheck.a
>  
> -# Additional library.
> -extra-libs = libmemusage
> +# Additional libraries.
> +extra-libs = libmemusage libc_malloc_debug
>  extra-libs-others = $(extra-libs)
>  
>  # Helper objects for some tests.
> @@ -138,6 +136,9 @@ test-extras = \
>  libmemusage-routines = memusage
>  libmemusage-inhibit-o = $(filter-out .os,$(object-suffixes))
>  
> +libc_malloc_debug-routines = malloc-debug
> +libc_malloc_debug-inhibit-o = $(filter-out .os,$(object-suffixes))
> +
>  $(objpfx)tst-malloc-backtrace: $(shared-thread-library)
>  $(objpfx)tst-malloc-thread-exit: $(shared-thread-library)
>  $(objpfx)tst-malloc-thread-fail: $(shared-thread-library)
> @@ -243,11 +244,12 @@ endif
>  endif
>  endif
>  
> -tst-malloc-check-ENV = MALLOC_CHECK_=3
> -tst-malloc-usable-ENV = MALLOC_CHECK_=3
> -tst-malloc-usable-static-ENV = $(tst-malloc-usable-ENV)
> -tst-malloc-usable-tunables-ENV = GLIBC_TUNABLES=glibc.malloc.check=3
> -tst-malloc-usable-static-tunables-ENV = $(tst-malloc-usable-tunables-ENV)
> +tst-malloc-check-ENV = MALLOC_CHECK_=3 \
> +		       LD_PRELOAD=$(objpfx)/libc_malloc_debug.so
> +tst-malloc-usable-ENV = MALLOC_CHECK_=3 \
> +		       LD_PRELOAD=$(objpfx)/libc_malloc_debug.so
> +tst-malloc-usable-tunables-ENV = GLIBC_TUNABLES=glibc.malloc.check=3 \
> +				 LD_PRELOAD=$(objpfx)/libc_malloc_debug.so
>  
>  tst-mxfast-ENV = GLIBC_TUNABLES=glibc.malloc.tcache_count=0:glibc.malloc.mxfast=0
>  
> @@ -302,12 +304,14 @@ $(objpfx)tst-interpose-static-thread-mcheck: \
>  $(objpfx)tst-interpose-static-thread-malloc-check: \
>    $(objpfx)tst-interpose-aux-thread.o $(static-thread-library)
>  
> -tst-dynarray-ENV = MALLOC_TRACE=$(objpfx)tst-dynarray.mtrace
> +tst-dynarray-ENV = MALLOC_TRACE=$(objpfx)tst-dynarray.mtrace \
> +		   LD_PRELOAD=$(objpfx)libc_malloc_debug.so
>  $(objpfx)tst-dynarray-mem.out: $(objpfx)tst-dynarray.out
>  	$(common-objpfx)malloc/mtrace $(objpfx)tst-dynarray.mtrace > $@; \
>  	$(evaluate-test)
>  
> -tst-dynarray-fail-ENV = MALLOC_TRACE=$(objpfx)tst-dynarray-fail.mtrace
> +tst-dynarray-fail-ENV = MALLOC_TRACE=$(objpfx)tst-dynarray-fail.mtrace \
> +			LD_PRELOAD=$(objpfx)libc_malloc_debug.so
>  $(objpfx)tst-dynarray-fail-mem.out: $(objpfx)tst-dynarray-fail.out
>  	$(common-objpfx)malloc/mtrace $(objpfx)tst-dynarray-fail.mtrace > $@; \
>  	$(evaluate-test)
> @@ -321,3 +325,10 @@ $(objpfx)tst-mallocfork2-mcheck: $(shared-thread-library)
>  $(objpfx)tst-malloc-tcache-leak-malloc-check: $(shared-thread-library)
>  $(objpfx)tst-malloc_info-malloc-check: $(shared-thread-library)
>  $(objpfx)tst-mallocfork2-malloc-check: $(shared-thread-library)
> +
> +tst-compathooks-on-ENV = LD_PRELOAD=$(objpfx)libc_malloc_debug.so
> +tst-compathooks-on-mcheck-ENV = LD_PRELOAD=$(objpfx)libc_malloc_debug.so
> +tst-compathooks-on-malloc-check-ENV = \
> +	LD_PRELOAD=$(objpfx)libc_malloc_debug.so
> +tst-mallocstate-ENV = LD_PRELOAD=$(objpfx)libc_malloc_debug.so
> +tst-mallocstate-malloc-check-ENV = LD_PRELOAD=$(objpfx)libc_malloc_debug.so
> diff --git a/malloc/Versions b/malloc/Versions
> index 470a940666..c87f6df8ca 100644
> --- a/malloc/Versions
> +++ b/malloc/Versions
> @@ -98,3 +98,23 @@ libc {
>      __libc_alloc_buffer_create_failure;
>    }
>  }
> +
> +# Keep in sync with symbols in libc.
> +libc_malloc_debug {
> +  GLIBC_2.0 {
> +    calloc;
> +    free;
> +    malloc;
> +    memalign;
> +    pvalloc;
> +    realloc;
> +    valloc;
> +
> +  }
> +  GLIBC_2.2 {
> +    posix_memalign;
> +  }
> +  GLIBC_2.16 {
> +    aligned_alloc;
> +  }
> +}
> diff --git a/malloc/arena.c b/malloc/arena.c
> index f1693ed48f..9111b49589 100644
> --- a/malloc/arena.c
> +++ b/malloc/arena.c
> @@ -404,13 +404,6 @@ ptmalloc_init (void)
>    if (s && s[0] != '\0' && s[0] != '0')
>      __malloc_check_init ();
>  #endif
> -
> -#if HAVE_MALLOC_INIT_HOOK
> -  void (*hook) (void) = atomic_forced_read (__malloc_initialize_hook);
> -  if (hook != NULL)
> -    (*hook)();
> -#endif
> -  __malloc_initialized = 1;
>  }
>  
>  /* Managing heaps and arenas (for concurrent threads) */
> diff --git a/malloc/hooks.c b/malloc/hooks.c
> index 4aa6dadcff..3cd44eeb84 100644
> --- a/malloc/hooks.c
> +++ b/malloc/hooks.c
> @@ -1,4 +1,4 @@
> -/* Malloc implementation for multiple threads without lock contention.
> +/* Compatibility code for malloc debugging and state management.
>     Copyright (C) 2001-2021 Free Software Foundation, Inc.
>     This file is part of the GNU C Library.
>     Contributed by Wolfram Gloger <wg@malloc.de>, 2001.
> @@ -17,6 +17,16 @@
>     License along with the GNU C Library; see the file COPYING.LIB.  If
>     not, see <https://www.gnu.org/licenses/>.  */
>  
> +#ifndef weak_variable
> +# define weak_variable weak_function
> +#endif
> +
> +#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_24)
> +void (*__malloc_initialize_hook) (void);
> +compat_symbol (libc, __malloc_initialize_hook,
> +	       __malloc_initialize_hook, GLIBC_2_0);
> +#endif
> +
>  #if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_34)
>  void weak_variable (*__after_morecore_hook) (void) = NULL;
>  compat_symbol (libc, __after_morecore_hook, __after_morecore_hook, GLIBC_2_0);
> @@ -24,32 +34,64 @@ void *(*__morecore)(ptrdiff_t);
>  compat_symbol (libc, __morecore, __morecore, GLIBC_2_0);
>  #endif
>  
> +static void *malloc_hook_ini (size_t, const void *) __THROW;
> +static void *realloc_hook_ini (void *, size_t, const void *) __THROW;
> +static void *memalign_hook_ini (size_t, size_t, const void *) __THROW;
> +
> +void weak_variable (*__free_hook) (void *, const void *) = NULL;
> +void *weak_variable (*__malloc_hook)
> +  (size_t, const void *) = malloc_hook_ini;
> +void *weak_variable (*__realloc_hook)
> +  (void *, size_t, const void *) = realloc_hook_ini;
> +void *weak_variable (*__memalign_hook)
> +  (size_t, size_t, const void *) = memalign_hook_ini;
> +
>  /* Hooks for debugging versions.  The initial hooks just call the
>     initialization routine, then do the normal work. */
>  
> -static void *
> -malloc_hook_ini (size_t sz, const void *caller)
> +/* These hooks will get executed only through the interposed allocator
> +   functions in libc_malloc_debug.so.  This means that the calls to malloc,
> +   realloc, etc. will lead back into the interposed functions, which is what we
> +   want.
> +
> +   These initial hooks are assumed to be called in a single-threaded context,
> +   so it is safe to reset all hooks at once upon initialization.  */
> +
> +static void
> +generic_hook_ini (void)
>  {
>    __malloc_hook = NULL;
> +  __realloc_hook = NULL;
> +  __memalign_hook = NULL;
>    ptmalloc_init ();
> -  return __libc_malloc (sz);
> +
> +#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_24)
> +  void (*hook) (void) = atomic_forced_read (__malloc_initialize_hook);
> +  if (hook != NULL)
> +    (*hook)();
> +#endif
> +  __malloc_initialized = 1;
> +}
> +
> +static void *
> +malloc_hook_ini (size_t sz, const void *caller)
> +{
> +  generic_hook_ini ();
> +  return malloc (sz);
>  }
>  
>  static void *
>  realloc_hook_ini (void *ptr, size_t sz, const void *caller)
>  {
> -  __malloc_hook = NULL;
> -  __realloc_hook = NULL;
> -  ptmalloc_init ();
> -  return __libc_realloc (ptr, sz);
> +  generic_hook_ini ();
> +  return realloc (ptr, sz);
>  }
>  
>  static void *
>  memalign_hook_ini (size_t alignment, size_t sz, const void *caller)
>  {
> -  __memalign_hook = NULL;
> -  ptmalloc_init ();
> -  return __libc_memalign (alignment, sz);
> +  generic_hook_ini ();
> +  return memalign (alignment, sz);
>  }
>  
>  #include "malloc-check.c"
> diff --git a/malloc/malloc-debug.c b/malloc/malloc-debug.c
> new file mode 100644
> index 0000000000..41dfcd3369
> --- /dev/null
> +++ b/malloc/malloc-debug.c
> @@ -0,0 +1,189 @@
> +/* Malloc debug DSO.
> +   Copyright (C) 2021 Free Software Foundation, Inc.
> +   This file is part of the GNU C Library.
> +
> +   The GNU C Library is free software; you can redistribute it and/or
> +   modify it under the terms of the GNU Lesser General Public License as
> +   published by the Free Software Foundation; either version 2.1 of the
> +   License, or (at your option) any later version.
> +
> +   The GNU C Library is distributed in the hope that it will be useful,
> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> +   Lesser General Public License for more details.
> +
> +   You should have received a copy of the GNU Lesser General Public
> +   License along with the GNU C Library; see the file COPYING.LIB.  If
> +   not, see <https://www.gnu.org/licenses/>.  */
> +
> +#include <atomic.h>
> +#include <libc-symbols.h>
> +#include <shlib-compat.h>
> +#include <string.h>
> +#include <unistd.h>
> +#include <sys/param.h>
> +
> +/* Support only the glibc allocators.  */
> +extern void *__libc_malloc (size_t);
> +extern void __libc_free (void *);
> +extern void *__libc_realloc (void *, size_t);
> +extern void *__libc_memalign (size_t, size_t);
> +extern void *__libc_valloc (size_t);
> +extern void *__libc_pvalloc (size_t);
> +extern void *__libc_calloc (size_t, size_t);
> +
> +#define DEBUG_FN(fn) \
> +  static __typeof (__libc_ ## fn) __debug_ ## fn
> +
> +DEBUG_FN(malloc);
> +DEBUG_FN(free);
> +DEBUG_FN(realloc);
> +DEBUG_FN(memalign);
> +DEBUG_FN(valloc);
> +DEBUG_FN(pvalloc);
> +DEBUG_FN(calloc);
> +
> +extern void (*__free_hook) (void *, const void *);
> +compat_symbol_reference (libc, __free_hook, __free_hook, GLIBC_2_0);
> +extern void * (*__malloc_hook) (size_t, const void *);
> +compat_symbol_reference (libc, __malloc_hook, __malloc_hook, GLIBC_2_0);
> +extern void * (*__realloc_hook) (void *, size_t, const void *);
> +compat_symbol_reference (libc, __realloc_hook, __realloc_hook, GLIBC_2_0);
> +extern void * (*__memalign_hook) (size_t, size_t, const void *);
> +compat_symbol_reference (libc, __memalign_hook, __memalign_hook, GLIBC_2_0);
> +
> +static size_t pagesize;
> +
> +/* The allocator functions.  */
> +
> +static void *
> +__debug_malloc (size_t bytes)
> +{
> +  void *(*hook) (size_t, const void *) = atomic_forced_read (__malloc_hook);
> +  if (__builtin_expect (hook != NULL, 0))
> +    return (*hook)(bytes, RETURN_ADDRESS (0));
> +
> +  return __libc_malloc (bytes);
> +}
> +strong_alias (__debug_malloc, malloc)
> +
> +static void
> +__debug_free (void *mem)
> +{
> +  void (*hook) (void *, const void *) = atomic_forced_read (__free_hook);
> +  if (__builtin_expect (hook != NULL, 0))
> +    {
> +      (*hook)(mem, RETURN_ADDRESS (0));
> +      return;
> +    }
> +  __libc_free (mem);
> +}
> +strong_alias (__debug_free, free)
> +
> +static void *
> +__debug_realloc (void *oldmem, size_t bytes)
> +{
> +  void *(*hook) (void *, size_t, const void *) =
> +    atomic_forced_read (__realloc_hook);
> +  if (__builtin_expect (hook != NULL, 0))
> +    return (*hook)(oldmem, bytes, RETURN_ADDRESS (0));
> +
> +  return __libc_realloc (oldmem, bytes);
> +}
> +strong_alias (__debug_realloc, realloc)
> +
> +static void *
> +_debug_mid_memalign (size_t alignment, size_t bytes, const void *address)
> +{
> +  void *(*hook) (size_t, size_t, const void *) =
> +    atomic_forced_read (__memalign_hook);
> +  if (__builtin_expect (hook != NULL, 0))
> +    return (*hook)(alignment, bytes, address);
> +
> +  return __libc_memalign (alignment, bytes);
> +}
> +
> +static void *
> +__debug_memalign (size_t alignment, size_t bytes)
> +{
> +  return _debug_mid_memalign (alignment, bytes, RETURN_ADDRESS (0));
> +}
> +strong_alias (__debug_memalign, memalign)
> +strong_alias (__debug_memalign, aligned_alloc)
> +
> +static void *
> +__debug_pvalloc (size_t bytes)
> +{
> +  size_t rounded_bytes;
> +
> +  if (!pagesize)
> +    pagesize = sysconf (_SC_PAGESIZE);
> +
> +  /* ALIGN_UP with overflow check.  */
> +  if (__glibc_unlikely (__builtin_add_overflow (bytes,
> +						pagesize - 1,
> +						&rounded_bytes)))
> +    {
> +      errno = ENOMEM;
> +      return NULL;
> +    }
> +  rounded_bytes = rounded_bytes & -(pagesize - 1);
> +
> +  return _debug_mid_memalign (pagesize, rounded_bytes, RETURN_ADDRESS (0));
> +}
> +strong_alias (__debug_pvalloc, pvalloc)
> +
> +static void *
> +__debug_valloc (size_t bytes)
> +{
> +  if (!pagesize)
> +    pagesize = sysconf (_SC_PAGESIZE);
> +
> +  return _debug_mid_memalign (pagesize, bytes, RETURN_ADDRESS (0));
> +}
> +strong_alias (__debug_valloc, valloc)
> +
> +static int
> +__debug_posix_memalign (void **memptr, size_t alignment, size_t bytes)
> +{
> +  /* Test whether the SIZE argument is valid.  It must be a power of
> +     two multiple of sizeof (void *).  */
> +  if (alignment % sizeof (void *) != 0
> +      || !powerof2 (alignment / sizeof (void *))
> +      || alignment == 0)
> +    return EINVAL;
> +
> +  *memptr = _debug_mid_memalign (alignment, bytes, RETURN_ADDRESS (0));
> +
> +  if (*memptr == NULL)
> +    return ENOMEM;
> +
> +  return 0;
> +}
> +strong_alias (__debug_posix_memalign, posix_memalign)
> +
> +static void *
> +__debug_calloc (size_t nmemb, size_t size)
> +{
> +  void *(*hook) (size_t, const void *) = atomic_forced_read (__malloc_hook);
> +  if (__builtin_expect (hook != NULL, 0))
> +    {
> +      size_t bytes;
> +
> +      if (__glibc_unlikely (__builtin_mul_overflow (nmemb, size, &bytes)))
> +	{
> +	  errno = ENOMEM;
> +	  return NULL;
> +	}
> +
> +      void *mem = (*hook)(bytes, RETURN_ADDRESS (0));
> +
> +      if (mem != NULL)
> +	memset (mem, 0, bytes);
> +
> +      return mem;
> +    }
> +
> +  return __libc_calloc (nmemb, size);
> +}
> +strong_alias (__debug_calloc, calloc)
> diff --git a/malloc/malloc.c b/malloc/malloc.c
> index 6e8fa9e424..cf71314b2b 100644
> --- a/malloc/malloc.c
> +++ b/malloc/malloc.c
> @@ -573,16 +573,6 @@ tag_at (void *ptr)
>  #define HAVE_MREMAP 0
>  #endif
>  
> -/* We may need to support __malloc_initialize_hook for backwards
> -   compatibility.  */
> -
> -#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_24)
> -# define HAVE_MALLOC_INIT_HOOK 1
> -#else
> -# define HAVE_MALLOC_INIT_HOOK 0
> -#endif
> -
> -
>  /*
>    This version of malloc supports the standard SVID/XPG mallinfo
>    routine that returns a struct containing usage properties and
> @@ -2008,38 +1998,6 @@ static void     malloc_consolidate (mstate);
>  
>  /* -------------- Early definitions for debugging hooks ---------------- */
>  
> -/* Define and initialize the hook variables.  These weak definitions must
> -   appear before any use of the variables in a function (arena.c uses one).  */
> -#ifndef weak_variable
> -/* In GNU libc we want the hook variables to be weak definitions to
> -   avoid a problem with Emacs.  */
> -# define weak_variable weak_function
> -#endif
> -
> -/* Forward declarations.  */
> -static void *malloc_hook_ini (size_t sz,
> -                              const void *caller) __THROW;
> -static void *realloc_hook_ini (void *ptr, size_t sz,
> -                               const void *caller) __THROW;
> -static void *memalign_hook_ini (size_t alignment, size_t sz,
> -                                const void *caller) __THROW;
> -
> -#if HAVE_MALLOC_INIT_HOOK
> -void (*__malloc_initialize_hook) (void);
> -compat_symbol (libc, __malloc_initialize_hook,
> -	       __malloc_initialize_hook, GLIBC_2_0);
> -#endif
> -
> -void weak_variable (*__free_hook) (void *__ptr,
> -                                   const void *) = NULL;
> -void *weak_variable (*__malloc_hook)
> -  (size_t __size, const void *) = malloc_hook_ini;
> -void *weak_variable (*__realloc_hook)
> -  (void *__ptr, size_t __size, const void *)
> -  = realloc_hook_ini;
> -void *weak_variable (*__memalign_hook)
> -  (size_t __alignment, size_t __size, const void *)
> -  = memalign_hook_ini;
>  /* This function is called from the arena shutdown hook, to free the
>     thread cache (if it exists).  */
>  static void tcache_thread_shutdown (void);
> @@ -3237,10 +3195,8 @@ __libc_malloc (size_t bytes)
>    _Static_assert (PTRDIFF_MAX <= SIZE_MAX / 2,
>                    "PTRDIFF_MAX is not more than half of SIZE_MAX");
>  
> -  void *(*hook) (size_t, const void *)
> -    = atomic_forced_read (__malloc_hook);
> -  if (__builtin_expect (hook != NULL, 0))
> -    return (*hook)(bytes, RETURN_ADDRESS (0));
> +  if (__malloc_initialized < 0)
> +    ptmalloc_init ();
>  #if USE_TCACHE
>    /* int_free also calls request2size, be careful to not pad twice.  */
>    size_t tbytes;
> @@ -3301,14 +3257,6 @@ __libc_free (void *mem)
>    mstate ar_ptr;
>    mchunkptr p;                          /* chunk corresponding to mem */
>  
> -  void (*hook) (void *, const void *)
> -    = atomic_forced_read (__free_hook);
> -  if (__builtin_expect (hook != NULL, 0))
> -    {
> -      (*hook)(mem, RETURN_ADDRESS (0));
> -      return;
> -    }
> -
>    if (mem == 0)                              /* free(0) has no effect */
>      return;
>  
> @@ -3360,10 +3308,8 @@ __libc_realloc (void *oldmem, size_t bytes)
>  
>    void *newp;             /* chunk to return */
>  
> -  void *(*hook) (void *, size_t, const void *) =
> -    atomic_forced_read (__realloc_hook);
> -  if (__builtin_expect (hook != NULL, 0))
> -    return (*hook)(oldmem, bytes, RETURN_ADDRESS (0));
> +  if (__malloc_initialized < 0)
> +    ptmalloc_init ();
>  
>  #if REALLOC_ZERO_BYTES_FREES
>    if (bytes == 0 && oldmem != NULL)
> @@ -3498,6 +3444,9 @@ libc_hidden_def (__libc_realloc)
>  void *
>  __libc_memalign (size_t alignment, size_t bytes)
>  {
> +  if (__malloc_initialized < 0)
> +    ptmalloc_init ();
> +
>    void *address = RETURN_ADDRESS (0);
>    return _mid_memalign (alignment, bytes, address);
>  }
> @@ -3508,11 +3457,6 @@ _mid_memalign (size_t alignment, size_t bytes, void *address)
>    mstate ar_ptr;
>    void *p;
>  
> -  void *(*hook) (size_t, size_t, const void *) =
> -    atomic_forced_read (__memalign_hook);
> -  if (__builtin_expect (hook != NULL, 0))
> -    return (*hook)(alignment, bytes, address);
> -
>    /* If we need less alignment than we give anyway, just relay to malloc.  */
>    if (alignment <= MALLOC_ALIGNMENT)
>      return __libc_malloc (bytes);
> @@ -3621,16 +3565,8 @@ __libc_calloc (size_t n, size_t elem_size)
>  
>    sz = bytes;
>  
> -  void *(*hook) (size_t, const void *) =
> -    atomic_forced_read (__malloc_hook);
> -  if (__builtin_expect (hook != NULL, 0))
> -    {
> -      mem = (*hook)(sz, RETURN_ADDRESS (0));
> -      if (mem == 0)
> -        return 0;
> -
> -      return memset (mem, 0, sz);
> -    }
> +  if (__malloc_initialized < 0)
> +    ptmalloc_init ();
>  
>    MAYBE_INIT_TCACHE ();
>  
> @@ -5659,6 +5595,9 @@ __posix_memalign (void **memptr, size_t alignment, size_t size)
>  {
>    void *mem;
>  
> +  if (__malloc_initialized < 0)
> +    ptmalloc_init ();
> +
>    /* Test whether the SIZE argument is valid.  It must be a power of
>       two multiple of sizeof (void *).  */
>    if (alignment % sizeof (void *) != 0
> diff --git a/malloc/mcheck.c b/malloc/mcheck.c
> index d2efcfb742..1e68cedbf5 100644
> --- a/malloc/mcheck.c
> +++ b/malloc/mcheck.c
> @@ -26,6 +26,7 @@
>  # include <stdio.h>
>  # include <libintl.h>
>  # include <errno.h>
> +# include <malloc-internal.h>
>  #endif
>  
>  /* Old hook values.  */
> diff --git a/malloc/mtrace.c b/malloc/mtrace.c
> index 6c2c58b706..fb58413d39 100644
> --- a/malloc/mtrace.c
> +++ b/malloc/mtrace.c
> @@ -22,6 +22,7 @@
>  # define _MALLOC_INTERNAL
>  # include <malloc.h>
>  # include <mcheck.h>
> +# include <malloc-internal.h>
>  # include <libc-lock.h>
>  #endif
>  
> diff --git a/malloc/tst-compathooks-off.c b/malloc/tst-compathooks-off.c
> new file mode 100644
> index 0000000000..7b3722d8b3
> --- /dev/null
> +++ b/malloc/tst-compathooks-off.c
> @@ -0,0 +1,145 @@
> +/* Minimal tests to verify libc_malloc_debug.so functionality.
> +   Copyright (C) 2021 Free Software Foundation, Inc.
> +   This file is part of the GNU C Library.
> +
> +   The GNU C Library is free software; you can redistribute it and/or
> +   modify it under the terms of the GNU Lesser General Public
> +   License as published by the Free Software Foundation; either
> +   version 2.1 of the License, or (at your option) any later version.
> +
> +   The GNU C Library is distributed in the hope that it will be useful,
> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> +   Lesser General Public License for more details.
> +
> +   You should have received a copy of the GNU Lesser General Public
> +   License along with the GNU C Library; if not, see
> +   <https://www.gnu.org/licenses/>.  */
> +
> +#include <stdio.h>
> +#include <stdlib.h>
> +#include <malloc.h>
> +#include <shlib-compat.h>
> +#include <libc-diag.h>
> +
> +#include <support/check.h>
> +#include <support/support.h>
> +
> +extern void (*volatile __free_hook) (void *, const void *);
> +extern void *(*volatile __malloc_hook)(size_t, const void *);
> +extern void *(*volatile __realloc_hook)(void *, size_t, const void *);
> +extern void *(*volatile __memalign_hook)(size_t, size_t, const void *);
> +
> +int hook_count, call_count;
> +
> +DIAG_PUSH_NEEDS_COMMENT;
> +DIAG_IGNORE_NEEDS_COMMENT (4.9, "-Wdeprecated-declarations");
> +
> +void
> +free_called (void *mem, const void *address)
> +{
> +  hook_count++;
> +  __free_hook = NULL;
> +  free (mem);
> +  __free_hook = free_called;
> +}
> +
> +void *
> +malloc_called (size_t bytes, const void *address)
> +{
> +  hook_count++;
> +  __malloc_hook = NULL;
> +  void *mem = malloc (bytes);
> +  __malloc_hook = malloc_called;
> +  return mem;
> +}
> +
> +void *
> +realloc_called (void *oldptr, size_t bytes, const void *address)
> +{
> +  hook_count++;
> +  __realloc_hook = NULL;
> +  void *mem = realloc (oldptr, bytes);
> +  __realloc_hook = realloc_called;
> +  return mem;
> +}
> +
> +void *
> +calloc_called (size_t n, size_t size, const void *address)
> +{
> +  hook_count++;
> +  __malloc_hook = NULL;
> +  void *mem = calloc (n, size);
> +  __malloc_hook = malloc_called;
> +  return mem;
> +}
> +
> +void *
> +memalign_called (size_t align, size_t size, const void *address)
> +{
> +  hook_count++;
> +  __memalign_hook = NULL;
> +  void *mem = memalign (align, size);
> +  __memalign_hook = memalign_called;
> +  return mem;
> +}
> +
> +static void initialize_hooks (void)
> +{
> +  __free_hook = free_called;
> +  __malloc_hook = malloc_called;
> +  __realloc_hook = realloc_called;
> +  __memalign_hook = memalign_called;
> +}
> +void (*__malloc_initialize_hook) (void) = initialize_hooks;
> +compat_symbol_reference (libc, __malloc_initialize_hook,
> +			 __malloc_initialize_hook, GLIBC_2_0);
> +compat_symbol_reference (libc, __free_hook,
> +			 __free_hook, GLIBC_2_0);
> +compat_symbol_reference (libc, __malloc_hook,
> +			 __malloc_hook, GLIBC_2_0);
> +compat_symbol_reference (libc, __realloc_hook,
> +			 __realloc_hook, GLIBC_2_0);
> +compat_symbol_reference (libc, __memalign_hook,
> +			 __memalign_hook, GLIBC_2_0);
> +
> +DIAG_POP_NEEDS_COMMENT;
> +
> +static int
> +do_test (void)
> +{
> +  void *p;
> +  p = malloc (0);
> +  TEST_VERIFY_EXIT (p != NULL);
> +  call_count++;
> +
> +  p = realloc (p, 0);
> +  TEST_VERIFY_EXIT (p == NULL);
> +  call_count++;
> +
> +  p = calloc (512, 1);
> +  TEST_VERIFY_EXIT (p != NULL);
> +  call_count++;
> +
> +  free (p);
> +  call_count++;
> +
> +  p = memalign (0x100, 0x100);
> +  TEST_VERIFY_EXIT (p != NULL);
> +  call_count++;
> +
> +  free (p);
> +  call_count++;
> +
> +  printf ("call_count: %d, hook_count: %d\n", call_count, hook_count);
> +
> +#ifdef HOOKS_ENABLED
> +  TEST_VERIFY_EXIT (call_count == hook_count);
> +#else
> +  TEST_VERIFY_EXIT (hook_count == 0);
> +#endif
> +
> +  exit (0);
> +}
> +
> +#include <support/test-driver.c>
> diff --git a/malloc/tst-compathooks-on.c b/malloc/tst-compathooks-on.c
> new file mode 100644
> index 0000000000..4da183687a
> --- /dev/null
> +++ b/malloc/tst-compathooks-on.c
> @@ -0,0 +1,2 @@
> +#define HOOKS_ENABLED 1
> +#include "tst-compathooks-off.c"
> diff --git a/malloc/tst-malloc-usable-static-tunables.c b/malloc/tst-malloc-usable-static-tunables.c
> deleted file mode 100644
> index 8907db01a5..0000000000
> --- a/malloc/tst-malloc-usable-static-tunables.c
> +++ /dev/null
> @@ -1 +0,0 @@
> -#include <malloc/tst-malloc-usable.c>
> diff --git a/malloc/tst-malloc-usable-static.c b/malloc/tst-malloc-usable-static.c
> deleted file mode 100644
> index 8907db01a5..0000000000
> --- a/malloc/tst-malloc-usable-static.c
> +++ /dev/null
> @@ -1 +0,0 @@
> -#include <malloc/tst-malloc-usable.c>
> diff --git a/malloc/tst-mtrace.sh b/malloc/tst-mtrace.sh
> index 9295683aff..a830204d5e 100755
> --- a/malloc/tst-mtrace.sh
> +++ b/malloc/tst-mtrace.sh
> @@ -30,6 +30,7 @@ trap "rm -f ${common_objpfx}malloc/tst-mtrace.leak; exit 1" 1 2 15
>  ${test_program_prefix_before_env} \
>  ${run_program_env} \
>  MALLOC_TRACE=${common_objpfx}malloc/tst-mtrace.leak \
> +LD_PRELOAD=${common_objpfx}malloc/libc_malloc_debug.so \
>  ${test_program_prefix_after_env} \
>    ${common_objpfx}malloc/tst-mtrace || status=1
>  
> diff --git a/manual/memory.texi b/manual/memory.texi
> index 31ee36be8c..93305f289b 100644
> --- a/manual/memory.texi
> +++ b/manual/memory.texi
> @@ -1256,8 +1256,9 @@ environment variable @env{MALLOC_ARENA_MAX} to the desired value.
>  @cindex consistency checking, of heap
>  
>  You can ask @code{malloc} to check the consistency of dynamic memory by
> -using the @code{mcheck} function.  This function is a GNU extension,
> -declared in @file{mcheck.h}.
> +using the @code{mcheck} function and preloading the malloc debug library
> +@file{libc_malloc_debug.so} using the @var{LD_PRELOAD} environment variable.
> +This function is a GNU extension, declared in @file{mcheck.h}.
>  @pindex mcheck.h
>  
>  @deftypefun int mcheck (void (*@var{abortfn}) (enum mcheck_status @var{status}))
> @@ -1368,7 +1369,10 @@ non-zero value less than 4, a special (less efficient) implementation is
>  used which is designed to be tolerant against simple errors, such as
>  double calls of @code{free} with the same argument, or overruns of a
>  single byte (off-by-one bugs).  Not all such errors can be protected
> -against, however, and memory leaks can result.
> +against, however, and memory leaks can result.  Like in the case of
> +@code{mcheck}, one would need to preload the @file{libc_malloc_debug.so}
> +library to enable @code{MALLOC_CHECK_} functionality.  Without this
> +preloaded library, setting @code{MALLOC_CHECK_} will have no effect.
>  
>  Any detected heap corruption results in immediate termination of the
>  process.
> @@ -1747,6 +1751,12 @@ penalties for the program if the debugging mode is not enabled.
>  @c  fprintf dup (on newly-created stream) @aculock
>  @c  __cxa_atexit (once) dup @asulock @aculock @acsmem
>  @c  free dup @ascuheap @acsmem
> +The @code{mtrace} function provides a way to trace memory allocation
> +events in the program that calls it.  It is disabled by default in the
> +library and can be enabled by preloading the debugging library
> +@file{libc_malloc_debug.so} using the @code{LD_PRELOAD} environment
> +variable.
> +
>  When the @code{mtrace} function is called it looks for an environment
>  variable named @code{MALLOC_TRACE}.  This variable is supposed to
>  contain a valid file name.  The user must have write access.  If the
> diff --git a/manual/tunables.texi b/manual/tunables.texi
> index ebdb562e36..e264e9150c 100644
> --- a/manual/tunables.texi
> +++ b/manual/tunables.texi
> @@ -113,7 +113,9 @@ following tunables in the @code{malloc} namespace:
>  
>  @deftp Tunable glibc.malloc.check
>  This tunable supersedes the @env{MALLOC_CHECK_} environment variable and is
> -identical in features.
> +identical in features. This tunable has no effect by default and needs the
> +debug library @file{libc_malloc_debug.so} to be preloaded using the
> +@code{LD_PRELOAD} environment variable.
>  
>  Setting this tunable to a non-zero value less than 4 enables a special (less
>  efficient) memory allocator for the @code{malloc} family of functions that is
> diff --git a/misc/Makefile b/misc/Makefile
> index ae03e26f1b..b144a3df6c 100644
> --- a/misc/Makefile
> +++ b/misc/Makefile
> @@ -152,13 +152,15 @@ $(objpfx)libg.a: $(dep-dummy-lib); $(make-dummy-lib)
>  
>  $(objpfx)tst-tsearch: $(libm)
>  
> -tst-error1-ENV = MALLOC_TRACE=$(objpfx)tst-error1.mtrace
> +tst-error1-ENV = MALLOC_TRACE=$(objpfx)tst-error1.mtrace \
> +		 LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
>  tst-error1-ARGS = $(objpfx)tst-error1.out
>  $(objpfx)tst-error1-mem.out: $(objpfx)tst-error1.out
>  	$(common-objpfx)malloc/mtrace $(objpfx)tst-error1.mtrace > $@; \
>  	$(evaluate-test)
>  
> -tst-allocate_once-ENV = MALLOC_TRACE=$(objpfx)tst-allocate_once.mtrace
> +tst-allocate_once-ENV = MALLOC_TRACE=$(objpfx)tst-allocate_once.mtrace \
> +			LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
>  $(objpfx)tst-allocate_once-mem.out: $(objpfx)tst-allocate_once.out
>  	$(common-objpfx)malloc/mtrace $(objpfx)tst-allocate_once.mtrace > $@; \
>  	$(evaluate-test)
> diff --git a/nptl/Makefile b/nptl/Makefile
> index 9b94bfcd31..ff4d590f11 100644
> --- a/nptl/Makefile
> +++ b/nptl/Makefile
> @@ -494,7 +494,8 @@ CFLAGS-tst-initializers1-gnu11.c += $(CFLAGS-tst-initializers1-<)
>  tst-cancel7-ARGS = --command "exec $(host-test-program-cmd)"
>  tst-cancelx7-ARGS = $(tst-cancel7-ARGS)
>  
> -tst-stack3-ENV = MALLOC_TRACE=$(objpfx)tst-stack3.mtrace
> +tst-stack3-ENV = MALLOC_TRACE=$(objpfx)tst-stack3.mtrace \
> +		 LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
>  $(objpfx)tst-stack3-mem.out: $(objpfx)tst-stack3.out
>  	$(common-objpfx)malloc/mtrace $(objpfx)tst-stack3.mtrace > $@; \
>  	$(evaluate-test)
> diff --git a/posix/Makefile b/posix/Makefile
> index d82e43eaad..b895638865 100644
> --- a/posix/Makefile
> +++ b/posix/Makefile
> @@ -313,43 +313,50 @@ annexc-CFLAGS = -O
>  $(objpfx)annexc: annexc.c
>  	$(native-compile)
>  
> -tst-fnmatch-ENV += MALLOC_TRACE=$(objpfx)tst-fnmatch.mtrace
> +tst-fnmatch-ENV += MALLOC_TRACE=$(objpfx)tst-fnmatch.mtrace \
> +		   LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
>  
>  $(objpfx)tst-fnmatch-mem.out: $(objpfx)tst-fnmatch.out
>  	$(common-objpfx)malloc/mtrace $(objpfx)tst-fnmatch.mtrace > $@; \
>  	$(evaluate-test)
>  
> -bug-regex2-ENV = MALLOC_TRACE=$(objpfx)bug-regex2.mtrace
> +bug-regex2-ENV = MALLOC_TRACE=$(objpfx)bug-regex2.mtrace \
> +		 LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
>  
>  $(objpfx)bug-regex2-mem.out: $(objpfx)bug-regex2.out
>  	$(common-objpfx)malloc/mtrace $(objpfx)bug-regex2.mtrace > $@; \
>  	$(evaluate-test)
>  
> -bug-regex14-ENV = MALLOC_TRACE=$(objpfx)bug-regex14.mtrace
> +bug-regex14-ENV = MALLOC_TRACE=$(objpfx)bug-regex14.mtrace \
> +		  LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
>  
>  $(objpfx)bug-regex14-mem.out: $(objpfx)bug-regex14.out
>  	$(common-objpfx)malloc/mtrace $(objpfx)bug-regex14.mtrace > $@; \
>  	$(evaluate-test)
>  
> -bug-regex21-ENV = MALLOC_TRACE=$(objpfx)bug-regex21.mtrace
> +bug-regex21-ENV = MALLOC_TRACE=$(objpfx)bug-regex21.mtrace \
> +		  LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
>  
>  $(objpfx)bug-regex21-mem.out: $(objpfx)bug-regex21.out
>  	$(common-objpfx)malloc/mtrace $(objpfx)bug-regex21.mtrace > $@; \
>  	$(evaluate-test)
>  
> -bug-regex31-ENV = MALLOC_TRACE=$(objpfx)bug-regex31.mtrace
> +bug-regex31-ENV = MALLOC_TRACE=$(objpfx)bug-regex31.mtrace \
> +		  LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
>  
>  $(objpfx)bug-regex31-mem.out: $(objpfx)bug-regex31.out
>  	$(common-objpfx)malloc/mtrace $(objpfx)bug-regex31.mtrace > $@; \
>  	$(evaluate-test)
>  
> -bug-regex36-ENV = MALLOC_TRACE=$(objpfx)bug-regex36.mtrace
> +bug-regex36-ENV = MALLOC_TRACE=$(objpfx)bug-regex36.mtrace \
> +		  LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
>  
>  $(objpfx)bug-regex36-mem.out: $(objpfx)bug-regex36.out
>  	$(common-objpfx)malloc/mtrace $(objpfx)bug-regex36.mtrace > $@; \
>  	$(evaluate-test)
>  
> -tst-vfork3-ENV = MALLOC_TRACE=$(objpfx)tst-vfork3.mtrace
> +tst-vfork3-ENV = MALLOC_TRACE=$(objpfx)tst-vfork3.mtrace \
> +		 LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
>  
>  $(objpfx)tst-vfork3-mem.out: $(objpfx)tst-vfork3.out
>  	$(common-objpfx)malloc/mtrace $(objpfx)tst-vfork3.mtrace > $@; \
> @@ -358,18 +365,22 @@ $(objpfx)tst-vfork3-mem.out: $(objpfx)tst-vfork3.out
>  # tst-rxspencer.mtrace is not generated, only
>  # tst-rxspencer-no-utf8.mtrace, since otherwise the file has almost
>  # 100M and takes very long time to process.
> -tst-rxspencer-no-utf8-ENV += MALLOC_TRACE=$(objpfx)tst-rxspencer-no-utf8.mtrace
> +tst-rxspencer-no-utf8-ENV += \
> +  MALLOC_TRACE=$(objpfx)tst-rxspencer-no-utf8.mtrace \
> +  LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
>  $(objpfx)tst-rxspencer-no-utf8-mem.out: $(objpfx)tst-rxspencer-no-utf8.out
>  	$(common-objpfx)malloc/mtrace $(objpfx)tst-rxspencer-no-utf8.mtrace \
>  				      > $@; \
>  	$(evaluate-test)
>  
> -tst-pcre-ENV = MALLOC_TRACE=$(objpfx)tst-pcre.mtrace
> +tst-pcre-ENV = MALLOC_TRACE=$(objpfx)tst-pcre.mtrace \
> +	       LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
>  $(objpfx)tst-pcre-mem.out: $(objpfx)tst-pcre.out
>  	$(common-objpfx)malloc/mtrace $(objpfx)tst-pcre.mtrace > $@; \
>  	$(evaluate-test)
>  
> -tst-boost-ENV = MALLOC_TRACE=$(objpfx)tst-boost.mtrace
> +tst-boost-ENV = MALLOC_TRACE=$(objpfx)tst-boost.mtrace \
> +		LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
>  $(objpfx)tst-boost-mem.out: $(objpfx)tst-boost.out
>  	$(common-objpfx)malloc/mtrace $(objpfx)tst-boost.mtrace > $@; \
>  	$(evaluate-test)
> @@ -384,15 +395,18 @@ $(objpfx)bug-ga2-mem.out: $(objpfx)bug-ga2.out
>  	&& $(common-objpfx)malloc/mtrace $(objpfx)bug-ga2.mtrace; } > $@; \
>  	$(evaluate-test)
>  
> -bug-ga2-ENV = MALLOC_TRACE=$(objpfx)bug-ga2.mtrace
> +bug-ga2-ENV = MALLOC_TRACE=$(objpfx)bug-ga2.mtrace \
> +	      LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
>  
> -bug-glob2-ENV = MALLOC_TRACE=$(objpfx)bug-glob2.mtrace
> +bug-glob2-ENV = MALLOC_TRACE=$(objpfx)bug-glob2.mtrace \
> +		LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
>  
>  $(objpfx)bug-glob2-mem.out: $(objpfx)bug-glob2.out
>  	$(common-objpfx)malloc/mtrace $(objpfx)bug-glob2.mtrace > $@; \
>  	$(evaluate-test)
>  
> -tst-glob-tilde-ENV = MALLOC_TRACE=$(objpfx)tst-glob-tilde.mtrace
> +tst-glob-tilde-ENV = MALLOC_TRACE=$(objpfx)tst-glob-tilde.mtrace \
> +		     LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
>  
>  $(objpfx)tst-glob-tilde-mem.out: $(objpfx)tst-glob-tilde.out
>  	$(common-objpfx)malloc/mtrace $(objpfx)tst-glob-tilde.mtrace > $@; \
> diff --git a/resolv/Makefile b/resolv/Makefile
> index 31d27454b4..c8721d9e62 100644
> --- a/resolv/Makefile
> +++ b/resolv/Makefile
> @@ -207,19 +207,22 @@ $(objpfx)tst-res_hconf_reorder: $(shared-thread-library)
>  tst-res_hconf_reorder-ENV = RESOLV_REORDER=on
>  
>  $(objpfx)tst-leaks: $(objpfx)libresolv.so
> -tst-leaks-ENV = MALLOC_TRACE=$(objpfx)tst-leaks.mtrace
> +tst-leaks-ENV = MALLOC_TRACE=$(objpfx)tst-leaks.mtrace \
> +		LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
>  $(objpfx)mtrace-tst-leaks.out: $(objpfx)tst-leaks.out
>  	$(common-objpfx)malloc/mtrace $(objpfx)tst-leaks.mtrace > $@; \
>  	$(evaluate-test)
>  
> -tst-leaks2-ENV = MALLOC_TRACE=$(objpfx)tst-leaks2.mtrace
> +tst-leaks2-ENV = MALLOC_TRACE=$(objpfx)tst-leaks2.mtrace \
> +		 LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
>  $(objpfx)mtrace-tst-leaks2.out: $(objpfx)tst-leaks2.out
>  	{ test -r $(objpfx)tst-leaks2.mtrace \
>  	|| ( echo "tst-leaks2.mtrace does not exist"; exit 77; ) \
>  	&& $(common-objpfx)malloc/mtrace $(objpfx)tst-leaks2.mtrace; } > $@; \
>  	$(evaluate-test)
>  
> -tst-resolv-res_ninit-ENV = MALLOC_TRACE=$(objpfx)tst-resolv-res_ninit.mtrace
> +tst-resolv-res_ninit-ENV = MALLOC_TRACE=$(objpfx)tst-resolv-res_ninit.mtrace \
> +			LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
>  $(objpfx)mtrace-tst-resolv-res_ninit.out: $(objpfx)tst-resolv-res_ninit.out
>  	$(common-objpfx)malloc/mtrace \
>  	  $(objpfx)tst-resolv-res_ninit.mtrace > $@; \
> diff --git a/shlib-versions b/shlib-versions
> index edabba08eb..df6603e699 100644
> --- a/shlib-versions
> +++ b/shlib-versions
> @@ -73,3 +73,6 @@ libgcc_s=1
>  
>  # The vector math library
>  libmvec=1
> +
> +# The malloc debug library
> +libc_malloc_debug=0
> diff --git a/stdio-common/Makefile b/stdio-common/Makefile
> index f87796a8ce..803f16dae0 100644
> --- a/stdio-common/Makefile
> +++ b/stdio-common/Makefile
> @@ -110,15 +110,20 @@ $(objpfx)tst-swprintf.out: $(gen-locales)
>  $(objpfx)tst-vfprintf-mbs-prec.out: $(gen-locales)
>  endif
>  
> -tst-printf-bz18872-ENV = MALLOC_TRACE=$(objpfx)tst-printf-bz18872.mtrace
> +tst-printf-bz18872-ENV = MALLOC_TRACE=$(objpfx)tst-printf-bz18872.mtrace \
> +			LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
>  tst-vfprintf-width-prec-ENV = \
> -  MALLOC_TRACE=$(objpfx)tst-vfprintf-width-prec.mtrace
> +  MALLOC_TRACE=$(objpfx)tst-vfprintf-width-prec.mtrace \
> +  LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
>  tst-printf-bz25691-ENV = \
> -  MALLOC_TRACE=$(objpfx)tst-printf-bz25691.mtrace
> +  MALLOC_TRACE=$(objpfx)tst-printf-bz25691.mtrace \
> +  LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
>  tst-printf-fp-free-ENV = \
> -  MALLOC_TRACE=$(objpfx)tst-printf-fp-free.mtrace
> +  MALLOC_TRACE=$(objpfx)tst-printf-fp-free.mtrace \
> +  LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
>  tst-printf-fp-leak-ENV = \
> -  MALLOC_TRACE=$(objpfx)tst-printf-fp-leak.mtrace
> +  MALLOC_TRACE=$(objpfx)tst-printf-fp-leak.mtrace \
> +  LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
>  
>  $(objpfx)tst-unbputc.out: tst-unbputc.sh $(objpfx)tst-unbputc
>  	$(SHELL) $< $(common-objpfx) '$(test-program-prefix)'; \
> diff --git a/sysdeps/generic/libc_malloc_debug.abilist b/sysdeps/generic/libc_malloc_debug.abilist
> new file mode 100644
> index 0000000000..e69de29bb2
> diff --git a/sysdeps/mach/hurd/Makefile b/sysdeps/mach/hurd/Makefile
> index 46bd7b4600..17bb643c18 100644
> --- a/sysdeps/mach/hurd/Makefile
> +++ b/sysdeps/mach/hurd/Makefile
> @@ -222,5 +222,6 @@ CFLAGS-ypclnt.c += -DUSE_BINDINGDIR=1
>  endif
>  
>  LDLIBS-pthread.so += $(objdir)/hurd/libhurduser.so
> +LDLIBS-c_malloc_debug.so += $(link-rpcuserlibs)
>  
>  endif	# in-Makerules
> diff --git a/sysdeps/mach/hurd/i386/libc_malloc_debug.abilist b/sysdeps/mach/hurd/i386/libc_malloc_debug.abilist
> new file mode 100644
> index 0000000000..393ef2acd7
> --- /dev/null
> +++ b/sysdeps/mach/hurd/i386/libc_malloc_debug.abilist
> @@ -0,0 +1,9 @@
> +GLIBC_2.16 aligned_alloc F
> +GLIBC_2.2.6 calloc F
> +GLIBC_2.2.6 free F
> +GLIBC_2.2.6 malloc F
> +GLIBC_2.2.6 memalign F
> +GLIBC_2.2.6 posix_memalign F
> +GLIBC_2.2.6 pvalloc F
> +GLIBC_2.2.6 realloc F
> +GLIBC_2.2.6 valloc F
> diff --git a/sysdeps/pthread/Makefile b/sysdeps/pthread/Makefile
> index 9b862b93c4..42f9fc5072 100644
> --- a/sysdeps/pthread/Makefile
> +++ b/sysdeps/pthread/Makefile
> @@ -211,7 +211,8 @@ tst-umask1-ARGS = $(objpfx)tst-umask1.temp
>  
>  $(objpfx)tst-atfork2: $(shared-thread-library)
>  LDFLAGS-tst-atfork2 = -rdynamic
> -tst-atfork2-ENV = MALLOC_TRACE=$(objpfx)tst-atfork2.mtrace
> +tst-atfork2-ENV = MALLOC_TRACE=$(objpfx)tst-atfork2.mtrace \
> +		  LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
>  $(objpfx)tst-atfork2mod.so: $(shared-thread-library)
>  
>  ifeq ($(build-shared),yes)
> diff --git a/sysdeps/unix/sysv/linux/aarch64/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/aarch64/libc_malloc_debug.abilist
> new file mode 100644
> index 0000000000..2b183c90d4
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/aarch64/libc_malloc_debug.abilist
> @@ -0,0 +1,9 @@
> +GLIBC_2.17 aligned_alloc F
> +GLIBC_2.17 calloc F
> +GLIBC_2.17 free F
> +GLIBC_2.17 malloc F
> +GLIBC_2.17 memalign F
> +GLIBC_2.17 posix_memalign F
> +GLIBC_2.17 pvalloc F
> +GLIBC_2.17 realloc F
> +GLIBC_2.17 valloc F
> diff --git a/sysdeps/unix/sysv/linux/alpha/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/alpha/libc_malloc_debug.abilist
> new file mode 100644
> index 0000000000..7621d1266e
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/alpha/libc_malloc_debug.abilist
> @@ -0,0 +1,9 @@
> +GLIBC_2.0 calloc F
> +GLIBC_2.0 free F
> +GLIBC_2.0 malloc F
> +GLIBC_2.0 memalign F
> +GLIBC_2.0 pvalloc F
> +GLIBC_2.0 realloc F
> +GLIBC_2.0 valloc F
> +GLIBC_2.16 aligned_alloc F
> +GLIBC_2.2 posix_memalign F
> diff --git a/sysdeps/unix/sysv/linux/arc/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/arc/libc_malloc_debug.abilist
> new file mode 100644
> index 0000000000..3ec745c9ac
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/arc/libc_malloc_debug.abilist
> @@ -0,0 +1,9 @@
> +GLIBC_2.32 aligned_alloc F
> +GLIBC_2.32 calloc F
> +GLIBC_2.32 free F
> +GLIBC_2.32 malloc F
> +GLIBC_2.32 memalign F
> +GLIBC_2.32 posix_memalign F
> +GLIBC_2.32 pvalloc F
> +GLIBC_2.32 realloc F
> +GLIBC_2.32 valloc F
> diff --git a/sysdeps/unix/sysv/linux/arm/be/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/arm/be/libc_malloc_debug.abilist
> new file mode 100644
> index 0000000000..f7938d075f
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/arm/be/libc_malloc_debug.abilist
> @@ -0,0 +1,9 @@
> +GLIBC_2.16 aligned_alloc F
> +GLIBC_2.4 calloc F
> +GLIBC_2.4 free F
> +GLIBC_2.4 malloc F
> +GLIBC_2.4 memalign F
> +GLIBC_2.4 posix_memalign F
> +GLIBC_2.4 pvalloc F
> +GLIBC_2.4 realloc F
> +GLIBC_2.4 valloc F
> diff --git a/sysdeps/unix/sysv/linux/arm/le/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/arm/le/libc_malloc_debug.abilist
> new file mode 100644
> index 0000000000..f7938d075f
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/arm/le/libc_malloc_debug.abilist
> @@ -0,0 +1,9 @@
> +GLIBC_2.16 aligned_alloc F
> +GLIBC_2.4 calloc F
> +GLIBC_2.4 free F
> +GLIBC_2.4 malloc F
> +GLIBC_2.4 memalign F
> +GLIBC_2.4 posix_memalign F
> +GLIBC_2.4 pvalloc F
> +GLIBC_2.4 realloc F
> +GLIBC_2.4 valloc F
> diff --git a/sysdeps/unix/sysv/linux/csky/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/csky/libc_malloc_debug.abilist
> new file mode 100644
> index 0000000000..54da2c3e38
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/csky/libc_malloc_debug.abilist
> @@ -0,0 +1,9 @@
> +GLIBC_2.29 aligned_alloc F
> +GLIBC_2.29 calloc F
> +GLIBC_2.29 free F
> +GLIBC_2.29 malloc F
> +GLIBC_2.29 memalign F
> +GLIBC_2.29 posix_memalign F
> +GLIBC_2.29 pvalloc F
> +GLIBC_2.29 realloc F
> +GLIBC_2.29 valloc F
> diff --git a/sysdeps/unix/sysv/linux/hppa/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/hppa/libc_malloc_debug.abilist
> new file mode 100644
> index 0000000000..3ea834d9a2
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/hppa/libc_malloc_debug.abilist
> @@ -0,0 +1,9 @@
> +GLIBC_2.16 aligned_alloc F
> +GLIBC_2.2 calloc F
> +GLIBC_2.2 free F
> +GLIBC_2.2 malloc F
> +GLIBC_2.2 memalign F
> +GLIBC_2.2 posix_memalign F
> +GLIBC_2.2 pvalloc F
> +GLIBC_2.2 realloc F
> +GLIBC_2.2 valloc F
> diff --git a/sysdeps/unix/sysv/linux/hppa/shlib-versions b/sysdeps/unix/sysv/linux/hppa/shlib-versions
> index 3a2d496220..7818a32cc4 100644
> --- a/sysdeps/unix/sysv/linux/hppa/shlib-versions
> +++ b/sysdeps/unix/sysv/linux/hppa/shlib-versions
> @@ -7,3 +7,5 @@ ld=ld.so.1		GLIBC_2.2
>  libBrokenLocale=1	GLIBC_2.2
>  
>  libpthread=0		GLIBC_2.2
> +
> +libc_malloc_debug=0	GLIBC_2.2
> diff --git a/sysdeps/unix/sysv/linux/i386/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/i386/libc_malloc_debug.abilist
> new file mode 100644
> index 0000000000..7621d1266e
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/i386/libc_malloc_debug.abilist
> @@ -0,0 +1,9 @@
> +GLIBC_2.0 calloc F
> +GLIBC_2.0 free F
> +GLIBC_2.0 malloc F
> +GLIBC_2.0 memalign F
> +GLIBC_2.0 pvalloc F
> +GLIBC_2.0 realloc F
> +GLIBC_2.0 valloc F
> +GLIBC_2.16 aligned_alloc F
> +GLIBC_2.2 posix_memalign F
> diff --git a/sysdeps/unix/sysv/linux/ia64/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/ia64/libc_malloc_debug.abilist
> new file mode 100644
> index 0000000000..3ea834d9a2
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/ia64/libc_malloc_debug.abilist
> @@ -0,0 +1,9 @@
> +GLIBC_2.16 aligned_alloc F
> +GLIBC_2.2 calloc F
> +GLIBC_2.2 free F
> +GLIBC_2.2 malloc F
> +GLIBC_2.2 memalign F
> +GLIBC_2.2 posix_memalign F
> +GLIBC_2.2 pvalloc F
> +GLIBC_2.2 realloc F
> +GLIBC_2.2 valloc F
> diff --git a/sysdeps/unix/sysv/linux/ia64/shlib-versions b/sysdeps/unix/sysv/linux/ia64/shlib-versions
> index 37374c0e20..f57e5bae5e 100644
> --- a/sysdeps/unix/sysv/linux/ia64/shlib-versions
> +++ b/sysdeps/unix/sysv/linux/ia64/shlib-versions
> @@ -6,3 +6,5 @@ ld=ld-linux-ia64.so.2	GLIBC_2.2
>  libBrokenLocale=1	GLIBC_2.2
>  
>  libpthread=0		GLIBC_2.2
> +
> +libc_malloc_debug=0	GLIBC_2.2
> diff --git a/sysdeps/unix/sysv/linux/m68k/coldfire/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/m68k/coldfire/libc_malloc_debug.abilist
> new file mode 100644
> index 0000000000..f7938d075f
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/m68k/coldfire/libc_malloc_debug.abilist
> @@ -0,0 +1,9 @@
> +GLIBC_2.16 aligned_alloc F
> +GLIBC_2.4 calloc F
> +GLIBC_2.4 free F
> +GLIBC_2.4 malloc F
> +GLIBC_2.4 memalign F
> +GLIBC_2.4 posix_memalign F
> +GLIBC_2.4 pvalloc F
> +GLIBC_2.4 realloc F
> +GLIBC_2.4 valloc F
> diff --git a/sysdeps/unix/sysv/linux/m68k/m680x0/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/m68k/m680x0/libc_malloc_debug.abilist
> new file mode 100644
> index 0000000000..7621d1266e
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/m68k/m680x0/libc_malloc_debug.abilist
> @@ -0,0 +1,9 @@
> +GLIBC_2.0 calloc F
> +GLIBC_2.0 free F
> +GLIBC_2.0 malloc F
> +GLIBC_2.0 memalign F
> +GLIBC_2.0 pvalloc F
> +GLIBC_2.0 realloc F
> +GLIBC_2.0 valloc F
> +GLIBC_2.16 aligned_alloc F
> +GLIBC_2.2 posix_memalign F
> diff --git a/sysdeps/unix/sysv/linux/microblaze/be/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/microblaze/be/libc_malloc_debug.abilist
> new file mode 100644
> index 0000000000..d02da8ef66
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/microblaze/be/libc_malloc_debug.abilist
> @@ -0,0 +1,9 @@
> +GLIBC_2.18 aligned_alloc F
> +GLIBC_2.18 calloc F
> +GLIBC_2.18 free F
> +GLIBC_2.18 malloc F
> +GLIBC_2.18 memalign F
> +GLIBC_2.18 posix_memalign F
> +GLIBC_2.18 pvalloc F
> +GLIBC_2.18 realloc F
> +GLIBC_2.18 valloc F
> diff --git a/sysdeps/unix/sysv/linux/microblaze/le/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/microblaze/le/libc_malloc_debug.abilist
> new file mode 100644
> index 0000000000..d02da8ef66
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/microblaze/le/libc_malloc_debug.abilist
> @@ -0,0 +1,9 @@
> +GLIBC_2.18 aligned_alloc F
> +GLIBC_2.18 calloc F
> +GLIBC_2.18 free F
> +GLIBC_2.18 malloc F
> +GLIBC_2.18 memalign F
> +GLIBC_2.18 posix_memalign F
> +GLIBC_2.18 pvalloc F
> +GLIBC_2.18 realloc F
> +GLIBC_2.18 valloc F
> diff --git a/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc_malloc_debug.abilist
> new file mode 100644
> index 0000000000..7621d1266e
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc_malloc_debug.abilist
> @@ -0,0 +1,9 @@
> +GLIBC_2.0 calloc F
> +GLIBC_2.0 free F
> +GLIBC_2.0 malloc F
> +GLIBC_2.0 memalign F
> +GLIBC_2.0 pvalloc F
> +GLIBC_2.0 realloc F
> +GLIBC_2.0 valloc F
> +GLIBC_2.16 aligned_alloc F
> +GLIBC_2.2 posix_memalign F
> diff --git a/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc_malloc_debug.abilist
> new file mode 100644
> index 0000000000..7621d1266e
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc_malloc_debug.abilist
> @@ -0,0 +1,9 @@
> +GLIBC_2.0 calloc F
> +GLIBC_2.0 free F
> +GLIBC_2.0 malloc F
> +GLIBC_2.0 memalign F
> +GLIBC_2.0 pvalloc F
> +GLIBC_2.0 realloc F
> +GLIBC_2.0 valloc F
> +GLIBC_2.16 aligned_alloc F
> +GLIBC_2.2 posix_memalign F
> diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n32/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/mips/mips64/n32/libc_malloc_debug.abilist
> new file mode 100644
> index 0000000000..7621d1266e
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/mips/mips64/n32/libc_malloc_debug.abilist
> @@ -0,0 +1,9 @@
> +GLIBC_2.0 calloc F
> +GLIBC_2.0 free F
> +GLIBC_2.0 malloc F
> +GLIBC_2.0 memalign F
> +GLIBC_2.0 pvalloc F
> +GLIBC_2.0 realloc F
> +GLIBC_2.0 valloc F
> +GLIBC_2.16 aligned_alloc F
> +GLIBC_2.2 posix_memalign F
> diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n64/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/mips/mips64/n64/libc_malloc_debug.abilist
> new file mode 100644
> index 0000000000..7621d1266e
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/mips/mips64/n64/libc_malloc_debug.abilist
> @@ -0,0 +1,9 @@
> +GLIBC_2.0 calloc F
> +GLIBC_2.0 free F
> +GLIBC_2.0 malloc F
> +GLIBC_2.0 memalign F
> +GLIBC_2.0 pvalloc F
> +GLIBC_2.0 realloc F
> +GLIBC_2.0 valloc F
> +GLIBC_2.16 aligned_alloc F
> +GLIBC_2.2 posix_memalign F
> diff --git a/sysdeps/unix/sysv/linux/mips/shlib-versions b/sysdeps/unix/sysv/linux/mips/shlib-versions
> index ecfe1845f4..c57674deec 100644
> --- a/sysdeps/unix/sysv/linux/mips/shlib-versions
> +++ b/sysdeps/unix/sysv/linux/mips/shlib-versions
> @@ -23,3 +23,5 @@ libnsl=1		GLIBC_2.0 GLIBC_2.2
>  librt=1			GLIBC_2.0 GLIBC_2.2
>  
>  libpthread=0		GLIBC_2.0 GLIBC_2.2
> +
> +libc_malloc_debug=0	GLIBC_2.0 GLIBC_2.2
> diff --git a/sysdeps/unix/sysv/linux/nios2/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/nios2/libc_malloc_debug.abilist
> new file mode 100644
> index 0000000000..658c965b08
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/nios2/libc_malloc_debug.abilist
> @@ -0,0 +1,9 @@
> +GLIBC_2.21 aligned_alloc F
> +GLIBC_2.21 calloc F
> +GLIBC_2.21 free F
> +GLIBC_2.21 malloc F
> +GLIBC_2.21 memalign F
> +GLIBC_2.21 posix_memalign F
> +GLIBC_2.21 pvalloc F
> +GLIBC_2.21 realloc F
> +GLIBC_2.21 valloc F
> diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc_malloc_debug.abilist
> new file mode 100644
> index 0000000000..7621d1266e
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc_malloc_debug.abilist
> @@ -0,0 +1,9 @@
> +GLIBC_2.0 calloc F
> +GLIBC_2.0 free F
> +GLIBC_2.0 malloc F
> +GLIBC_2.0 memalign F
> +GLIBC_2.0 pvalloc F
> +GLIBC_2.0 realloc F
> +GLIBC_2.0 valloc F
> +GLIBC_2.16 aligned_alloc F
> +GLIBC_2.2 posix_memalign F
> diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc_malloc_debug.abilist
> new file mode 100644
> index 0000000000..7621d1266e
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc_malloc_debug.abilist
> @@ -0,0 +1,9 @@
> +GLIBC_2.0 calloc F
> +GLIBC_2.0 free F
> +GLIBC_2.0 malloc F
> +GLIBC_2.0 memalign F
> +GLIBC_2.0 pvalloc F
> +GLIBC_2.0 realloc F
> +GLIBC_2.0 valloc F
> +GLIBC_2.16 aligned_alloc F
> +GLIBC_2.2 posix_memalign F
> diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/be/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc64/be/libc_malloc_debug.abilist
> new file mode 100644
> index 0000000000..921079580c
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/be/libc_malloc_debug.abilist
> @@ -0,0 +1,9 @@
> +GLIBC_2.16 aligned_alloc F
> +GLIBC_2.3 calloc F
> +GLIBC_2.3 free F
> +GLIBC_2.3 malloc F
> +GLIBC_2.3 memalign F
> +GLIBC_2.3 posix_memalign F
> +GLIBC_2.3 pvalloc F
> +GLIBC_2.3 realloc F
> +GLIBC_2.3 valloc F
> diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libc_malloc_debug.abilist
> new file mode 100644
> index 0000000000..2b183c90d4
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libc_malloc_debug.abilist
> @@ -0,0 +1,9 @@
> +GLIBC_2.17 aligned_alloc F
> +GLIBC_2.17 calloc F
> +GLIBC_2.17 free F
> +GLIBC_2.17 malloc F
> +GLIBC_2.17 memalign F
> +GLIBC_2.17 posix_memalign F
> +GLIBC_2.17 pvalloc F
> +GLIBC_2.17 realloc F
> +GLIBC_2.17 valloc F
> diff --git a/sysdeps/unix/sysv/linux/riscv/rv32/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/riscv/rv32/libc_malloc_debug.abilist
> new file mode 100644
> index 0000000000..05c8ba8c9f
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/riscv/rv32/libc_malloc_debug.abilist
> @@ -0,0 +1,9 @@
> +GLIBC_2.33 aligned_alloc F
> +GLIBC_2.33 calloc F
> +GLIBC_2.33 free F
> +GLIBC_2.33 malloc F
> +GLIBC_2.33 memalign F
> +GLIBC_2.33 posix_memalign F
> +GLIBC_2.33 pvalloc F
> +GLIBC_2.33 realloc F
> +GLIBC_2.33 valloc F
> diff --git a/sysdeps/unix/sysv/linux/riscv/rv64/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/riscv/rv64/libc_malloc_debug.abilist
> new file mode 100644
> index 0000000000..20531a7372
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/riscv/rv64/libc_malloc_debug.abilist
> @@ -0,0 +1,9 @@
> +GLIBC_2.27 aligned_alloc F
> +GLIBC_2.27 calloc F
> +GLIBC_2.27 free F
> +GLIBC_2.27 malloc F
> +GLIBC_2.27 memalign F
> +GLIBC_2.27 posix_memalign F
> +GLIBC_2.27 pvalloc F
> +GLIBC_2.27 realloc F
> +GLIBC_2.27 valloc F
> diff --git a/sysdeps/unix/sysv/linux/s390/s390-32/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/s390/s390-32/libc_malloc_debug.abilist
> new file mode 100644
> index 0000000000..7621d1266e
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/s390/s390-32/libc_malloc_debug.abilist
> @@ -0,0 +1,9 @@
> +GLIBC_2.0 calloc F
> +GLIBC_2.0 free F
> +GLIBC_2.0 malloc F
> +GLIBC_2.0 memalign F
> +GLIBC_2.0 pvalloc F
> +GLIBC_2.0 realloc F
> +GLIBC_2.0 valloc F
> +GLIBC_2.16 aligned_alloc F
> +GLIBC_2.2 posix_memalign F
> diff --git a/sysdeps/unix/sysv/linux/s390/s390-64/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/s390/s390-64/libc_malloc_debug.abilist
> new file mode 100644
> index 0000000000..3ea834d9a2
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/s390/s390-64/libc_malloc_debug.abilist
> @@ -0,0 +1,9 @@
> +GLIBC_2.16 aligned_alloc F
> +GLIBC_2.2 calloc F
> +GLIBC_2.2 free F
> +GLIBC_2.2 malloc F
> +GLIBC_2.2 memalign F
> +GLIBC_2.2 posix_memalign F
> +GLIBC_2.2 pvalloc F
> +GLIBC_2.2 realloc F
> +GLIBC_2.2 valloc F
> diff --git a/sysdeps/unix/sysv/linux/sh/be/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/sh/be/libc_malloc_debug.abilist
> new file mode 100644
> index 0000000000..3ea834d9a2
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/sh/be/libc_malloc_debug.abilist
> @@ -0,0 +1,9 @@
> +GLIBC_2.16 aligned_alloc F
> +GLIBC_2.2 calloc F
> +GLIBC_2.2 free F
> +GLIBC_2.2 malloc F
> +GLIBC_2.2 memalign F
> +GLIBC_2.2 posix_memalign F
> +GLIBC_2.2 pvalloc F
> +GLIBC_2.2 realloc F
> +GLIBC_2.2 valloc F
> diff --git a/sysdeps/unix/sysv/linux/sh/le/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/sh/le/libc_malloc_debug.abilist
> new file mode 100644
> index 0000000000..3ea834d9a2
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/sh/le/libc_malloc_debug.abilist
> @@ -0,0 +1,9 @@
> +GLIBC_2.16 aligned_alloc F
> +GLIBC_2.2 calloc F
> +GLIBC_2.2 free F
> +GLIBC_2.2 malloc F
> +GLIBC_2.2 memalign F
> +GLIBC_2.2 posix_memalign F
> +GLIBC_2.2 pvalloc F
> +GLIBC_2.2 realloc F
> +GLIBC_2.2 valloc F
> diff --git a/sysdeps/unix/sysv/linux/sh/shlib-versions b/sysdeps/unix/sysv/linux/sh/shlib-versions
> index 9333bbd7a3..3124264300 100644
> --- a/sysdeps/unix/sysv/linux/sh/shlib-versions
> +++ b/sysdeps/unix/sysv/linux/sh/shlib-versions
> @@ -3,3 +3,4 @@ libc=6			GLIBC_2.2
>  ld=ld-linux.so.2	GLIBC_2.2
>  libBrokenLocale=1	GLIBC_2.2
>  libpthread=0		GLIBC_2.2
> +libc_malloc_debug=0	GLIBC_2.2
> diff --git a/sysdeps/unix/sysv/linux/sparc/sparc32/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/sparc/sparc32/libc_malloc_debug.abilist
> new file mode 100644
> index 0000000000..7621d1266e
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/sparc/sparc32/libc_malloc_debug.abilist
> @@ -0,0 +1,9 @@
> +GLIBC_2.0 calloc F
> +GLIBC_2.0 free F
> +GLIBC_2.0 malloc F
> +GLIBC_2.0 memalign F
> +GLIBC_2.0 pvalloc F
> +GLIBC_2.0 realloc F
> +GLIBC_2.0 valloc F
> +GLIBC_2.16 aligned_alloc F
> +GLIBC_2.2 posix_memalign F
> diff --git a/sysdeps/unix/sysv/linux/sparc/sparc64/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/sparc/sparc64/libc_malloc_debug.abilist
> new file mode 100644
> index 0000000000..3ea834d9a2
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/sparc/sparc64/libc_malloc_debug.abilist
> @@ -0,0 +1,9 @@
> +GLIBC_2.16 aligned_alloc F
> +GLIBC_2.2 calloc F
> +GLIBC_2.2 free F
> +GLIBC_2.2 malloc F
> +GLIBC_2.2 memalign F
> +GLIBC_2.2 posix_memalign F
> +GLIBC_2.2 pvalloc F
> +GLIBC_2.2 realloc F
> +GLIBC_2.2 valloc F
> diff --git a/sysdeps/unix/sysv/linux/sparc/sparc64/shlib-versions b/sysdeps/unix/sysv/linux/sparc/sparc64/shlib-versions
> index 9333bbd7a3..3124264300 100644
> --- a/sysdeps/unix/sysv/linux/sparc/sparc64/shlib-versions
> +++ b/sysdeps/unix/sysv/linux/sparc/sparc64/shlib-versions
> @@ -3,3 +3,4 @@ libc=6			GLIBC_2.2
>  ld=ld-linux.so.2	GLIBC_2.2
>  libBrokenLocale=1	GLIBC_2.2
>  libpthread=0		GLIBC_2.2
> +libc_malloc_debug=0	GLIBC_2.2
> diff --git a/sysdeps/unix/sysv/linux/x86_64/64/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/x86_64/64/libc_malloc_debug.abilist
> new file mode 100644
> index 0000000000..723c5f48f0
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/x86_64/64/libc_malloc_debug.abilist
> @@ -0,0 +1,9 @@
> +GLIBC_2.16 aligned_alloc F
> +GLIBC_2.2.5 calloc F
> +GLIBC_2.2.5 free F
> +GLIBC_2.2.5 malloc F
> +GLIBC_2.2.5 memalign F
> +GLIBC_2.2.5 posix_memalign F
> +GLIBC_2.2.5 pvalloc F
> +GLIBC_2.2.5 realloc F
> +GLIBC_2.2.5 valloc F
> diff --git a/sysdeps/unix/sysv/linux/x86_64/x32/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/x86_64/x32/libc_malloc_debug.abilist
> new file mode 100644
> index 0000000000..c506f45101
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/x86_64/x32/libc_malloc_debug.abilist
> @@ -0,0 +1,9 @@
> +GLIBC_2.16 aligned_alloc F
> +GLIBC_2.16 calloc F
> +GLIBC_2.16 free F
> +GLIBC_2.16 malloc F
> +GLIBC_2.16 memalign F
> +GLIBC_2.16 posix_memalign F
> +GLIBC_2.16 pvalloc F
> +GLIBC_2.16 realloc F
> +GLIBC_2.16 valloc F
>
diff mbox series

Patch

diff --git a/NEWS b/NEWS
index 75ad8a9b95..fa80c9685b 100644
--- a/NEWS
+++ b/NEWS
@@ -132,6 +132,12 @@  Deprecated and removed features, and other changes affecting compatibility:
   applications will continue to link against these symbols but the interfaces
   no longer have any effect on malloc.
 
+* Debugging features in malloc such as the MALLOC_CHECK_ environment variable
+  (or the glibc.malloc.check tunable), mtrace() and mcheck() have now been
+  disabled by default in the main C library.  Users looking to use these
+  features now need to preload a new debugging DSO libc_malloc_debug.so to get
+  this functionality back.
+
 Changes to build and runtime requirements:
 
 * On Linux, the shm_open, sem_open, and related functions now expect the
diff --git a/Rules b/Rules
index ba13598df6..b1137afe71 100644
--- a/Rules
+++ b/Rules
@@ -279,10 +279,17 @@  endif
 
 # All malloc-check tests will be run with MALLOC_CHECK_=3
 define malloc-check-ENVS
-$(1)-malloc-check-ENV = MALLOC_CHECK_=3
+$(1)-malloc-check-ENV = MALLOC_CHECK_=3 \
+			LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
 endef
 $(foreach t,$(tests-malloc-check),$(eval $(call malloc-check-ENVS,$(t))))
 
+# mcheck tests need the debug DSO to support -lmcheck.
+define mcheck-ENVS
+$(1)-mcheck-ENV = LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
+endef
+$(foreach t,$(tests-mcheck),$(eval $(call mcheck-ENVS,$(t))))
+
 ifneq "$(strip $(tests) $(tests-internal) $(xtests) $(test-srcs))" ""
 # These are the implicit rules for making test outputs
 # from the test programs and whatever input files are present.
diff --git a/catgets/Makefile b/catgets/Makefile
index 54da9a985f..215965b352 100644
--- a/catgets/Makefile
+++ b/catgets/Makefile
@@ -56,7 +56,9 @@  generated += tst-catgets.mtrace tst-catgets-mem.out
 
 generated-dirs += de
 
-tst-catgets-ENV = NLSPATH="$(objpfx)%l/%N.cat" LANG=de MALLOC_TRACE=$(objpfx)tst-catgets.mtrace
+tst-catgets-ENV = NLSPATH="$(objpfx)%l/%N.cat" LANG=de \
+		  MALLOC_TRACE=$(objpfx)tst-catgets.mtrace \
+		  LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
 
 ifeq ($(run-built-tests),yes)
 # This test just checks whether the program produces any error or not.
diff --git a/elf/Makefile b/elf/Makefile
index 4fe60947ad..87a70d6c7a 100644
--- a/elf/Makefile
+++ b/elf/Makefile
@@ -156,7 +156,7 @@  $(inst_auditdir)/sotruss-lib.so: $(objpfx)sotruss-lib.so $(+force)
 	$(do-install-program)
 endif
 
-tests-static-normal := tst-leaks1-static tst-array1-static tst-array5-static \
+tests-static-normal := tst-array1-static tst-array5-static \
 	       tst-dl-iter-static \
 	       tst-tlsalign-static tst-tlsalign-extern-static \
 	       tst-linkall-static tst-env-setuid tst-env-setuid-tunables \
@@ -242,7 +242,7 @@  endif
 tests += $(tests-execstack-$(have-z-execstack))
 ifeq ($(run-built-tests),yes)
 tests-special += $(objpfx)tst-leaks1-mem.out \
-		 $(objpfx)tst-leaks1-static-mem.out $(objpfx)noload-mem.out \
+		 $(objpfx)noload-mem.out \
 		 $(objpfx)tst-ldconfig-X.out $(objpfx)tst-rtld-help.out
 endif
 tlsmod17a-suffixes = 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
@@ -904,7 +904,8 @@  $(objpfx)noload.out: $(objpfx)testobj5.so
 $(objpfx)noload-mem.out: $(objpfx)noload.out
 	$(common-objpfx)malloc/mtrace $(objpfx)noload.mtrace > $@; \
 	$(evaluate-test)
-noload-ENV = MALLOC_TRACE=$(objpfx)noload.mtrace
+noload-ENV = MALLOC_TRACE=$(objpfx)noload.mtrace \
+	     LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
 
 LDFLAGS-nodelete = -rdynamic
 LDFLAGS-nodelmod1.so = -Wl,--enable-new-dtags,-z,nodelete
@@ -1282,12 +1283,8 @@  $(objpfx)tst-leaks1-mem.out: $(objpfx)tst-leaks1.out
 	$(common-objpfx)malloc/mtrace $(objpfx)tst-leaks1.mtrace > $@; \
 	$(evaluate-test)
 
-$(objpfx)tst-leaks1-static-mem.out: $(objpfx)tst-leaks1-static.out
-	$(common-objpfx)malloc/mtrace $(objpfx)tst-leaks1-static.mtrace > $@; \
-	$(evaluate-test)
-
-tst-leaks1-ENV = MALLOC_TRACE=$(objpfx)tst-leaks1.mtrace
-tst-leaks1-static-ENV = MALLOC_TRACE=$(objpfx)tst-leaks1-static.mtrace
+tst-leaks1-ENV = MALLOC_TRACE=$(objpfx)tst-leaks1.mtrace \
+		 LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
 
 $(objpfx)tst-thrlock: $(shared-thread-library)
 $(objpfx)tst-thrlock.out: $(libm)
diff --git a/elf/tst-leaks1-static.c b/elf/tst-leaks1-static.c
deleted file mode 100644
index b956d66905..0000000000
--- a/elf/tst-leaks1-static.c
+++ /dev/null
@@ -1 +0,0 @@ 
-#include "tst-leaks1.c"
diff --git a/iconvdata/Makefile b/iconvdata/Makefile
index bb3f621b49..c216f959df 100644
--- a/iconvdata/Makefile
+++ b/iconvdata/Makefile
@@ -301,7 +301,8 @@  cpp-srcs-left := $(modules) $(generated-modules) $(libJIS-routines) \
 lib := iconvdata
 include $(patsubst %,$(..)libof-iterator.mk,$(cpp-srcs-left))
 
-tst-loading-ENV = MALLOC_TRACE=$(objpfx)tst-loading.mtrace
+tst-loading-ENV = MALLOC_TRACE=$(objpfx)tst-loading.mtrace \
+		  LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
 $(objpfx)mtrace-tst-loading.out: $(objpfx)tst-loading.out
 	$(common-objpfx)malloc/mtrace $(objpfx)tst-loading.mtrace > $@; \
 	$(evaluate-test)
diff --git a/intl/tst-gettext.sh b/intl/tst-gettext.sh
index 77864de18c..37d9fcb80a 100755
--- a/intl/tst-gettext.sh
+++ b/intl/tst-gettext.sh
@@ -50,6 +50,7 @@  msgfmt -o ${objpfx}domaindir/existing-locale/LC_TIME/existing-time-domain.mo \
 ${test_program_prefix_before_env} \
 ${run_program_env} \
 MALLOC_TRACE=$malloc_trace \
+LD_PRELOAD=${common_objpfx}malloc/libc_malloc_debug.so \
 LOCPATH=${objpfx}localedir:${common_objpfx}localedata \
 ${test_program_prefix_after_env} \
 ${objpfx}tst-gettext > ${objpfx}tst-gettext.out ${objpfx}domaindir
diff --git a/libio/Makefile b/libio/Makefile
index 73f731e064..5336b7d595 100644
--- a/libio/Makefile
+++ b/libio/Makefile
@@ -165,10 +165,14 @@  LDFLAGS-tst-bz24228 = -Wl,--version-script=tst-bz24228.map
 
 tst_wprintf2-ARGS = "Some Text"
 
-test-fmemopen-ENV = MALLOC_TRACE=$(objpfx)test-fmemopen.mtrace
-tst-fopenloc-ENV = MALLOC_TRACE=$(objpfx)tst-fopenloc.mtrace
-tst-bz22415-ENV = MALLOC_TRACE=$(objpfx)tst-bz22415.mtrace
-tst-bz24228-ENV = MALLOC_TRACE=$(objpfx)tst-bz24228.mtrace
+test-fmemopen-ENV = MALLOC_TRACE=$(objpfx)test-fmemopen.mtrace \
+		    LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
+tst-fopenloc-ENV = MALLOC_TRACE=$(objpfx)tst-fopenloc.mtrace \
+		   LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
+tst-bz22415-ENV = MALLOC_TRACE=$(objpfx)tst-bz22415.mtrace \
+		  LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
+tst-bz24228-ENV = MALLOC_TRACE=$(objpfx)tst-bz24228.mtrace \
+		  LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
 
 generated += test-fmemopen.mtrace test-fmemopen.check
 generated += tst-fopenloc.mtrace tst-fopenloc.check
diff --git a/localedata/Makefile b/localedata/Makefile
index 14e04cd3c5..f585e0dd41 100644
--- a/localedata/Makefile
+++ b/localedata/Makefile
@@ -456,7 +456,8 @@  $(INSTALL-SUPPORTED-LOCALE-FILES): install-locales-dir
 tst-setlocale-ENV = LC_ALL=ja_JP.EUC-JP
 tst-wctype-ENV = LC_ALL=ja_JP.EUC-JP
 
-tst-leaks-ENV = MALLOC_TRACE=$(objpfx)tst-leaks.mtrace
+tst-leaks-ENV = MALLOC_TRACE=$(objpfx)tst-leaks.mtrace \
+		LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
 $(objpfx)mtrace-tst-leaks.out: $(objpfx)tst-leaks.out
 	$(common-objpfx)malloc/mtrace $(objpfx)tst-leaks.mtrace > $@; \
 	$(evaluate-test)
diff --git a/malloc/Makefile b/malloc/Makefile
index ef5b485ffb..89d27d482f 100644
--- a/malloc/Makefile
+++ b/malloc/Makefile
@@ -46,12 +46,11 @@  tests := mallocbug tst-malloc tst-valloc tst-calloc tst-obstack \
 
 tests-static := \
 	 tst-interpose-static-nothread \
-	 tst-interpose-static-thread \
-	 tst-malloc-usable-static \
+	 tst-interpose-static-thread
 
 # Test for the malloc_set_state symbol removed in glibc 2.25.
-ifeq ($(have-GLIBC_2.24)$(build-shared),yesyes)
-tests += tst-mallocstate
+ifeq ($(have-GLIBC_2.23)$(build-shared),yesyes)
+tests += tst-mallocstate tst-compathooks-off tst-compathooks-on
 endif
 
 tests-internal := tst-scratch_buffer
@@ -64,7 +63,6 @@  tests-internal += \
 
 ifneq (no,$(have-tunables))
 tests += tst-malloc-usable-tunables tst-mxfast
-tests-static += tst-malloc-usable-static-tunables
 endif
 
 tests += $(tests-static)
@@ -73,7 +71,8 @@  test-srcs = tst-mtrace
 # These tests either are run with MALLOC_CHECK_=3 by default or do not work
 # with MALLOC_CHECK_=3 because they expect a specific failure.
 tests-exclude-malloc-check = tst-malloc-check tst-malloc-usable \
-	tst-mxfast tst-safe-linking
+	tst-mxfast tst-safe-linking \
+	tst-compathooks-off tst-compathooks-on
 
 # Run all tests with MALLOC_CHECK_=3
 tests-malloc-check = $(filter-out $(tests-exclude-malloc-check),$(tests))
@@ -91,15 +90,14 @@  tests-exclude-mcheck = tst-mallocstate \
 	tst-malloc-tcache-leak \
 	tst-malloc-thread-exit \
 	tst-malloc-thread-fail \
-	tst-malloc-usable-static \
-	tst-malloc-usable-static-tunables \
 	tst-malloc-usable-tunables \
 	tst-malloc_info \
 	tst-memalign \
 	tst-posix_memalign \
 	tst-realloc \
 	tst-pvalloc-fortify \
-	tst-reallocarray
+	tst-reallocarray \
+	tst-compathooks-off tst-compathooks-on
 
 tests-mcheck = $(filter-out $(tests-exclude-mcheck), $(tests))
 endif
@@ -122,8 +120,8 @@  routines = malloc mcheck mtrace obstack reallocarray \
 install-lib := libmcheck.a
 non-lib.a := libmcheck.a
 
-# Additional library.
-extra-libs = libmemusage
+# Additional libraries.
+extra-libs = libmemusage libc_malloc_debug
 extra-libs-others = $(extra-libs)
 
 # Helper objects for some tests.
@@ -138,6 +136,9 @@  test-extras = \
 libmemusage-routines = memusage
 libmemusage-inhibit-o = $(filter-out .os,$(object-suffixes))
 
+libc_malloc_debug-routines = malloc-debug
+libc_malloc_debug-inhibit-o = $(filter-out .os,$(object-suffixes))
+
 $(objpfx)tst-malloc-backtrace: $(shared-thread-library)
 $(objpfx)tst-malloc-thread-exit: $(shared-thread-library)
 $(objpfx)tst-malloc-thread-fail: $(shared-thread-library)
@@ -243,11 +244,12 @@  endif
 endif
 endif
 
-tst-malloc-check-ENV = MALLOC_CHECK_=3
-tst-malloc-usable-ENV = MALLOC_CHECK_=3
-tst-malloc-usable-static-ENV = $(tst-malloc-usable-ENV)
-tst-malloc-usable-tunables-ENV = GLIBC_TUNABLES=glibc.malloc.check=3
-tst-malloc-usable-static-tunables-ENV = $(tst-malloc-usable-tunables-ENV)
+tst-malloc-check-ENV = MALLOC_CHECK_=3 \
+		       LD_PRELOAD=$(objpfx)/libc_malloc_debug.so
+tst-malloc-usable-ENV = MALLOC_CHECK_=3 \
+		       LD_PRELOAD=$(objpfx)/libc_malloc_debug.so
+tst-malloc-usable-tunables-ENV = GLIBC_TUNABLES=glibc.malloc.check=3 \
+				 LD_PRELOAD=$(objpfx)/libc_malloc_debug.so
 
 tst-mxfast-ENV = GLIBC_TUNABLES=glibc.malloc.tcache_count=0:glibc.malloc.mxfast=0
 
@@ -302,12 +304,14 @@  $(objpfx)tst-interpose-static-thread-mcheck: \
 $(objpfx)tst-interpose-static-thread-malloc-check: \
   $(objpfx)tst-interpose-aux-thread.o $(static-thread-library)
 
-tst-dynarray-ENV = MALLOC_TRACE=$(objpfx)tst-dynarray.mtrace
+tst-dynarray-ENV = MALLOC_TRACE=$(objpfx)tst-dynarray.mtrace \
+		   LD_PRELOAD=$(objpfx)libc_malloc_debug.so
 $(objpfx)tst-dynarray-mem.out: $(objpfx)tst-dynarray.out
 	$(common-objpfx)malloc/mtrace $(objpfx)tst-dynarray.mtrace > $@; \
 	$(evaluate-test)
 
-tst-dynarray-fail-ENV = MALLOC_TRACE=$(objpfx)tst-dynarray-fail.mtrace
+tst-dynarray-fail-ENV = MALLOC_TRACE=$(objpfx)tst-dynarray-fail.mtrace \
+			LD_PRELOAD=$(objpfx)libc_malloc_debug.so
 $(objpfx)tst-dynarray-fail-mem.out: $(objpfx)tst-dynarray-fail.out
 	$(common-objpfx)malloc/mtrace $(objpfx)tst-dynarray-fail.mtrace > $@; \
 	$(evaluate-test)
@@ -321,3 +325,10 @@  $(objpfx)tst-mallocfork2-mcheck: $(shared-thread-library)
 $(objpfx)tst-malloc-tcache-leak-malloc-check: $(shared-thread-library)
 $(objpfx)tst-malloc_info-malloc-check: $(shared-thread-library)
 $(objpfx)tst-mallocfork2-malloc-check: $(shared-thread-library)
+
+tst-compathooks-on-ENV = LD_PRELOAD=$(objpfx)libc_malloc_debug.so
+tst-compathooks-on-mcheck-ENV = LD_PRELOAD=$(objpfx)libc_malloc_debug.so
+tst-compathooks-on-malloc-check-ENV = \
+	LD_PRELOAD=$(objpfx)libc_malloc_debug.so
+tst-mallocstate-ENV = LD_PRELOAD=$(objpfx)libc_malloc_debug.so
+tst-mallocstate-malloc-check-ENV = LD_PRELOAD=$(objpfx)libc_malloc_debug.so
diff --git a/malloc/Versions b/malloc/Versions
index 470a940666..c87f6df8ca 100644
--- a/malloc/Versions
+++ b/malloc/Versions
@@ -98,3 +98,23 @@  libc {
     __libc_alloc_buffer_create_failure;
   }
 }
+
+# Keep in sync with symbols in libc.
+libc_malloc_debug {
+  GLIBC_2.0 {
+    calloc;
+    free;
+    malloc;
+    memalign;
+    pvalloc;
+    realloc;
+    valloc;
+
+  }
+  GLIBC_2.2 {
+    posix_memalign;
+  }
+  GLIBC_2.16 {
+    aligned_alloc;
+  }
+}
diff --git a/malloc/arena.c b/malloc/arena.c
index f1693ed48f..9111b49589 100644
--- a/malloc/arena.c
+++ b/malloc/arena.c
@@ -404,13 +404,6 @@  ptmalloc_init (void)
   if (s && s[0] != '\0' && s[0] != '0')
     __malloc_check_init ();
 #endif
-
-#if HAVE_MALLOC_INIT_HOOK
-  void (*hook) (void) = atomic_forced_read (__malloc_initialize_hook);
-  if (hook != NULL)
-    (*hook)();
-#endif
-  __malloc_initialized = 1;
 }
 
 /* Managing heaps and arenas (for concurrent threads) */
diff --git a/malloc/hooks.c b/malloc/hooks.c
index 4aa6dadcff..3cd44eeb84 100644
--- a/malloc/hooks.c
+++ b/malloc/hooks.c
@@ -1,4 +1,4 @@ 
-/* Malloc implementation for multiple threads without lock contention.
+/* Compatibility code for malloc debugging and state management.
    Copyright (C) 2001-2021 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Wolfram Gloger <wg@malloc.de>, 2001.
@@ -17,6 +17,16 @@ 
    License along with the GNU C Library; see the file COPYING.LIB.  If
    not, see <https://www.gnu.org/licenses/>.  */
 
+#ifndef weak_variable
+# define weak_variable weak_function
+#endif
+
+#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_24)
+void (*__malloc_initialize_hook) (void);
+compat_symbol (libc, __malloc_initialize_hook,
+	       __malloc_initialize_hook, GLIBC_2_0);
+#endif
+
 #if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_34)
 void weak_variable (*__after_morecore_hook) (void) = NULL;
 compat_symbol (libc, __after_morecore_hook, __after_morecore_hook, GLIBC_2_0);
@@ -24,32 +34,64 @@  void *(*__morecore)(ptrdiff_t);
 compat_symbol (libc, __morecore, __morecore, GLIBC_2_0);
 #endif
 
+static void *malloc_hook_ini (size_t, const void *) __THROW;
+static void *realloc_hook_ini (void *, size_t, const void *) __THROW;
+static void *memalign_hook_ini (size_t, size_t, const void *) __THROW;
+
+void weak_variable (*__free_hook) (void *, const void *) = NULL;
+void *weak_variable (*__malloc_hook)
+  (size_t, const void *) = malloc_hook_ini;
+void *weak_variable (*__realloc_hook)
+  (void *, size_t, const void *) = realloc_hook_ini;
+void *weak_variable (*__memalign_hook)
+  (size_t, size_t, const void *) = memalign_hook_ini;
+
 /* Hooks for debugging versions.  The initial hooks just call the
    initialization routine, then do the normal work. */
 
-static void *
-malloc_hook_ini (size_t sz, const void *caller)
+/* These hooks will get executed only through the interposed allocator
+   functions in libc_malloc_debug.so.  This means that the calls to malloc,
+   realloc, etc. will lead back into the interposed functions, which is what we
+   want.
+
+   These initial hooks are assumed to be called in a single-threaded context,
+   so it is safe to reset all hooks at once upon initialization.  */
+
+static void
+generic_hook_ini (void)
 {
   __malloc_hook = NULL;
+  __realloc_hook = NULL;
+  __memalign_hook = NULL;
   ptmalloc_init ();
-  return __libc_malloc (sz);
+
+#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_24)
+  void (*hook) (void) = atomic_forced_read (__malloc_initialize_hook);
+  if (hook != NULL)
+    (*hook)();
+#endif
+  __malloc_initialized = 1;
+}
+
+static void *
+malloc_hook_ini (size_t sz, const void *caller)
+{
+  generic_hook_ini ();
+  return malloc (sz);
 }
 
 static void *
 realloc_hook_ini (void *ptr, size_t sz, const void *caller)
 {
-  __malloc_hook = NULL;
-  __realloc_hook = NULL;
-  ptmalloc_init ();
-  return __libc_realloc (ptr, sz);
+  generic_hook_ini ();
+  return realloc (ptr, sz);
 }
 
 static void *
 memalign_hook_ini (size_t alignment, size_t sz, const void *caller)
 {
-  __memalign_hook = NULL;
-  ptmalloc_init ();
-  return __libc_memalign (alignment, sz);
+  generic_hook_ini ();
+  return memalign (alignment, sz);
 }
 
 #include "malloc-check.c"
diff --git a/malloc/malloc-debug.c b/malloc/malloc-debug.c
new file mode 100644
index 0000000000..41dfcd3369
--- /dev/null
+++ b/malloc/malloc-debug.c
@@ -0,0 +1,189 @@ 
+/* Malloc debug DSO.
+   Copyright (C) 2021 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public License as
+   published by the Free Software Foundation; either version 2.1 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If
+   not, see <https://www.gnu.org/licenses/>.  */
+
+#include <atomic.h>
+#include <libc-symbols.h>
+#include <shlib-compat.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/param.h>
+
+/* Support only the glibc allocators.  */
+extern void *__libc_malloc (size_t);
+extern void __libc_free (void *);
+extern void *__libc_realloc (void *, size_t);
+extern void *__libc_memalign (size_t, size_t);
+extern void *__libc_valloc (size_t);
+extern void *__libc_pvalloc (size_t);
+extern void *__libc_calloc (size_t, size_t);
+
+#define DEBUG_FN(fn) \
+  static __typeof (__libc_ ## fn) __debug_ ## fn
+
+DEBUG_FN(malloc);
+DEBUG_FN(free);
+DEBUG_FN(realloc);
+DEBUG_FN(memalign);
+DEBUG_FN(valloc);
+DEBUG_FN(pvalloc);
+DEBUG_FN(calloc);
+
+extern void (*__free_hook) (void *, const void *);
+compat_symbol_reference (libc, __free_hook, __free_hook, GLIBC_2_0);
+extern void * (*__malloc_hook) (size_t, const void *);
+compat_symbol_reference (libc, __malloc_hook, __malloc_hook, GLIBC_2_0);
+extern void * (*__realloc_hook) (void *, size_t, const void *);
+compat_symbol_reference (libc, __realloc_hook, __realloc_hook, GLIBC_2_0);
+extern void * (*__memalign_hook) (size_t, size_t, const void *);
+compat_symbol_reference (libc, __memalign_hook, __memalign_hook, GLIBC_2_0);
+
+static size_t pagesize;
+
+/* The allocator functions.  */
+
+static void *
+__debug_malloc (size_t bytes)
+{
+  void *(*hook) (size_t, const void *) = atomic_forced_read (__malloc_hook);
+  if (__builtin_expect (hook != NULL, 0))
+    return (*hook)(bytes, RETURN_ADDRESS (0));
+
+  return __libc_malloc (bytes);
+}
+strong_alias (__debug_malloc, malloc)
+
+static void
+__debug_free (void *mem)
+{
+  void (*hook) (void *, const void *) = atomic_forced_read (__free_hook);
+  if (__builtin_expect (hook != NULL, 0))
+    {
+      (*hook)(mem, RETURN_ADDRESS (0));
+      return;
+    }
+  __libc_free (mem);
+}
+strong_alias (__debug_free, free)
+
+static void *
+__debug_realloc (void *oldmem, size_t bytes)
+{
+  void *(*hook) (void *, size_t, const void *) =
+    atomic_forced_read (__realloc_hook);
+  if (__builtin_expect (hook != NULL, 0))
+    return (*hook)(oldmem, bytes, RETURN_ADDRESS (0));
+
+  return __libc_realloc (oldmem, bytes);
+}
+strong_alias (__debug_realloc, realloc)
+
+static void *
+_debug_mid_memalign (size_t alignment, size_t bytes, const void *address)
+{
+  void *(*hook) (size_t, size_t, const void *) =
+    atomic_forced_read (__memalign_hook);
+  if (__builtin_expect (hook != NULL, 0))
+    return (*hook)(alignment, bytes, address);
+
+  return __libc_memalign (alignment, bytes);
+}
+
+static void *
+__debug_memalign (size_t alignment, size_t bytes)
+{
+  return _debug_mid_memalign (alignment, bytes, RETURN_ADDRESS (0));
+}
+strong_alias (__debug_memalign, memalign)
+strong_alias (__debug_memalign, aligned_alloc)
+
+static void *
+__debug_pvalloc (size_t bytes)
+{
+  size_t rounded_bytes;
+
+  if (!pagesize)
+    pagesize = sysconf (_SC_PAGESIZE);
+
+  /* ALIGN_UP with overflow check.  */
+  if (__glibc_unlikely (__builtin_add_overflow (bytes,
+						pagesize - 1,
+						&rounded_bytes)))
+    {
+      errno = ENOMEM;
+      return NULL;
+    }
+  rounded_bytes = rounded_bytes & -(pagesize - 1);
+
+  return _debug_mid_memalign (pagesize, rounded_bytes, RETURN_ADDRESS (0));
+}
+strong_alias (__debug_pvalloc, pvalloc)
+
+static void *
+__debug_valloc (size_t bytes)
+{
+  if (!pagesize)
+    pagesize = sysconf (_SC_PAGESIZE);
+
+  return _debug_mid_memalign (pagesize, bytes, RETURN_ADDRESS (0));
+}
+strong_alias (__debug_valloc, valloc)
+
+static int
+__debug_posix_memalign (void **memptr, size_t alignment, size_t bytes)
+{
+  /* Test whether the SIZE argument is valid.  It must be a power of
+     two multiple of sizeof (void *).  */
+  if (alignment % sizeof (void *) != 0
+      || !powerof2 (alignment / sizeof (void *))
+      || alignment == 0)
+    return EINVAL;
+
+  *memptr = _debug_mid_memalign (alignment, bytes, RETURN_ADDRESS (0));
+
+  if (*memptr == NULL)
+    return ENOMEM;
+
+  return 0;
+}
+strong_alias (__debug_posix_memalign, posix_memalign)
+
+static void *
+__debug_calloc (size_t nmemb, size_t size)
+{
+  void *(*hook) (size_t, const void *) = atomic_forced_read (__malloc_hook);
+  if (__builtin_expect (hook != NULL, 0))
+    {
+      size_t bytes;
+
+      if (__glibc_unlikely (__builtin_mul_overflow (nmemb, size, &bytes)))
+	{
+	  errno = ENOMEM;
+	  return NULL;
+	}
+
+      void *mem = (*hook)(bytes, RETURN_ADDRESS (0));
+
+      if (mem != NULL)
+	memset (mem, 0, bytes);
+
+      return mem;
+    }
+
+  return __libc_calloc (nmemb, size);
+}
+strong_alias (__debug_calloc, calloc)
diff --git a/malloc/malloc.c b/malloc/malloc.c
index 6e8fa9e424..cf71314b2b 100644
--- a/malloc/malloc.c
+++ b/malloc/malloc.c
@@ -573,16 +573,6 @@  tag_at (void *ptr)
 #define HAVE_MREMAP 0
 #endif
 
-/* We may need to support __malloc_initialize_hook for backwards
-   compatibility.  */
-
-#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_24)
-# define HAVE_MALLOC_INIT_HOOK 1
-#else
-# define HAVE_MALLOC_INIT_HOOK 0
-#endif
-
-
 /*
   This version of malloc supports the standard SVID/XPG mallinfo
   routine that returns a struct containing usage properties and
@@ -2008,38 +1998,6 @@  static void     malloc_consolidate (mstate);
 
 /* -------------- Early definitions for debugging hooks ---------------- */
 
-/* Define and initialize the hook variables.  These weak definitions must
-   appear before any use of the variables in a function (arena.c uses one).  */
-#ifndef weak_variable
-/* In GNU libc we want the hook variables to be weak definitions to
-   avoid a problem with Emacs.  */
-# define weak_variable weak_function
-#endif
-
-/* Forward declarations.  */
-static void *malloc_hook_ini (size_t sz,
-                              const void *caller) __THROW;
-static void *realloc_hook_ini (void *ptr, size_t sz,
-                               const void *caller) __THROW;
-static void *memalign_hook_ini (size_t alignment, size_t sz,
-                                const void *caller) __THROW;
-
-#if HAVE_MALLOC_INIT_HOOK
-void (*__malloc_initialize_hook) (void);
-compat_symbol (libc, __malloc_initialize_hook,
-	       __malloc_initialize_hook, GLIBC_2_0);
-#endif
-
-void weak_variable (*__free_hook) (void *__ptr,
-                                   const void *) = NULL;
-void *weak_variable (*__malloc_hook)
-  (size_t __size, const void *) = malloc_hook_ini;
-void *weak_variable (*__realloc_hook)
-  (void *__ptr, size_t __size, const void *)
-  = realloc_hook_ini;
-void *weak_variable (*__memalign_hook)
-  (size_t __alignment, size_t __size, const void *)
-  = memalign_hook_ini;
 /* This function is called from the arena shutdown hook, to free the
    thread cache (if it exists).  */
 static void tcache_thread_shutdown (void);
@@ -3237,10 +3195,8 @@  __libc_malloc (size_t bytes)
   _Static_assert (PTRDIFF_MAX <= SIZE_MAX / 2,
                   "PTRDIFF_MAX is not more than half of SIZE_MAX");
 
-  void *(*hook) (size_t, const void *)
-    = atomic_forced_read (__malloc_hook);
-  if (__builtin_expect (hook != NULL, 0))
-    return (*hook)(bytes, RETURN_ADDRESS (0));
+  if (__malloc_initialized < 0)
+    ptmalloc_init ();
 #if USE_TCACHE
   /* int_free also calls request2size, be careful to not pad twice.  */
   size_t tbytes;
@@ -3301,14 +3257,6 @@  __libc_free (void *mem)
   mstate ar_ptr;
   mchunkptr p;                          /* chunk corresponding to mem */
 
-  void (*hook) (void *, const void *)
-    = atomic_forced_read (__free_hook);
-  if (__builtin_expect (hook != NULL, 0))
-    {
-      (*hook)(mem, RETURN_ADDRESS (0));
-      return;
-    }
-
   if (mem == 0)                              /* free(0) has no effect */
     return;
 
@@ -3360,10 +3308,8 @@  __libc_realloc (void *oldmem, size_t bytes)
 
   void *newp;             /* chunk to return */
 
-  void *(*hook) (void *, size_t, const void *) =
-    atomic_forced_read (__realloc_hook);
-  if (__builtin_expect (hook != NULL, 0))
-    return (*hook)(oldmem, bytes, RETURN_ADDRESS (0));
+  if (__malloc_initialized < 0)
+    ptmalloc_init ();
 
 #if REALLOC_ZERO_BYTES_FREES
   if (bytes == 0 && oldmem != NULL)
@@ -3498,6 +3444,9 @@  libc_hidden_def (__libc_realloc)
 void *
 __libc_memalign (size_t alignment, size_t bytes)
 {
+  if (__malloc_initialized < 0)
+    ptmalloc_init ();
+
   void *address = RETURN_ADDRESS (0);
   return _mid_memalign (alignment, bytes, address);
 }
@@ -3508,11 +3457,6 @@  _mid_memalign (size_t alignment, size_t bytes, void *address)
   mstate ar_ptr;
   void *p;
 
-  void *(*hook) (size_t, size_t, const void *) =
-    atomic_forced_read (__memalign_hook);
-  if (__builtin_expect (hook != NULL, 0))
-    return (*hook)(alignment, bytes, address);
-
   /* If we need less alignment than we give anyway, just relay to malloc.  */
   if (alignment <= MALLOC_ALIGNMENT)
     return __libc_malloc (bytes);
@@ -3621,16 +3565,8 @@  __libc_calloc (size_t n, size_t elem_size)
 
   sz = bytes;
 
-  void *(*hook) (size_t, const void *) =
-    atomic_forced_read (__malloc_hook);
-  if (__builtin_expect (hook != NULL, 0))
-    {
-      mem = (*hook)(sz, RETURN_ADDRESS (0));
-      if (mem == 0)
-        return 0;
-
-      return memset (mem, 0, sz);
-    }
+  if (__malloc_initialized < 0)
+    ptmalloc_init ();
 
   MAYBE_INIT_TCACHE ();
 
@@ -5659,6 +5595,9 @@  __posix_memalign (void **memptr, size_t alignment, size_t size)
 {
   void *mem;
 
+  if (__malloc_initialized < 0)
+    ptmalloc_init ();
+
   /* Test whether the SIZE argument is valid.  It must be a power of
      two multiple of sizeof (void *).  */
   if (alignment % sizeof (void *) != 0
diff --git a/malloc/mcheck.c b/malloc/mcheck.c
index d2efcfb742..1e68cedbf5 100644
--- a/malloc/mcheck.c
+++ b/malloc/mcheck.c
@@ -26,6 +26,7 @@ 
 # include <stdio.h>
 # include <libintl.h>
 # include <errno.h>
+# include <malloc-internal.h>
 #endif
 
 /* Old hook values.  */
diff --git a/malloc/mtrace.c b/malloc/mtrace.c
index 6c2c58b706..fb58413d39 100644
--- a/malloc/mtrace.c
+++ b/malloc/mtrace.c
@@ -22,6 +22,7 @@ 
 # define _MALLOC_INTERNAL
 # include <malloc.h>
 # include <mcheck.h>
+# include <malloc-internal.h>
 # include <libc-lock.h>
 #endif
 
diff --git a/malloc/tst-compathooks-off.c b/malloc/tst-compathooks-off.c
new file mode 100644
index 0000000000..7b3722d8b3
--- /dev/null
+++ b/malloc/tst-compathooks-off.c
@@ -0,0 +1,145 @@ 
+/* Minimal tests to verify libc_malloc_debug.so functionality.
+   Copyright (C) 2021 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <malloc.h>
+#include <shlib-compat.h>
+#include <libc-diag.h>
+
+#include <support/check.h>
+#include <support/support.h>
+
+extern void (*volatile __free_hook) (void *, const void *);
+extern void *(*volatile __malloc_hook)(size_t, const void *);
+extern void *(*volatile __realloc_hook)(void *, size_t, const void *);
+extern void *(*volatile __memalign_hook)(size_t, size_t, const void *);
+
+int hook_count, call_count;
+
+DIAG_PUSH_NEEDS_COMMENT;
+DIAG_IGNORE_NEEDS_COMMENT (4.9, "-Wdeprecated-declarations");
+
+void
+free_called (void *mem, const void *address)
+{
+  hook_count++;
+  __free_hook = NULL;
+  free (mem);
+  __free_hook = free_called;
+}
+
+void *
+malloc_called (size_t bytes, const void *address)
+{
+  hook_count++;
+  __malloc_hook = NULL;
+  void *mem = malloc (bytes);
+  __malloc_hook = malloc_called;
+  return mem;
+}
+
+void *
+realloc_called (void *oldptr, size_t bytes, const void *address)
+{
+  hook_count++;
+  __realloc_hook = NULL;
+  void *mem = realloc (oldptr, bytes);
+  __realloc_hook = realloc_called;
+  return mem;
+}
+
+void *
+calloc_called (size_t n, size_t size, const void *address)
+{
+  hook_count++;
+  __malloc_hook = NULL;
+  void *mem = calloc (n, size);
+  __malloc_hook = malloc_called;
+  return mem;
+}
+
+void *
+memalign_called (size_t align, size_t size, const void *address)
+{
+  hook_count++;
+  __memalign_hook = NULL;
+  void *mem = memalign (align, size);
+  __memalign_hook = memalign_called;
+  return mem;
+}
+
+static void initialize_hooks (void)
+{
+  __free_hook = free_called;
+  __malloc_hook = malloc_called;
+  __realloc_hook = realloc_called;
+  __memalign_hook = memalign_called;
+}
+void (*__malloc_initialize_hook) (void) = initialize_hooks;
+compat_symbol_reference (libc, __malloc_initialize_hook,
+			 __malloc_initialize_hook, GLIBC_2_0);
+compat_symbol_reference (libc, __free_hook,
+			 __free_hook, GLIBC_2_0);
+compat_symbol_reference (libc, __malloc_hook,
+			 __malloc_hook, GLIBC_2_0);
+compat_symbol_reference (libc, __realloc_hook,
+			 __realloc_hook, GLIBC_2_0);
+compat_symbol_reference (libc, __memalign_hook,
+			 __memalign_hook, GLIBC_2_0);
+
+DIAG_POP_NEEDS_COMMENT;
+
+static int
+do_test (void)
+{
+  void *p;
+  p = malloc (0);
+  TEST_VERIFY_EXIT (p != NULL);
+  call_count++;
+
+  p = realloc (p, 0);
+  TEST_VERIFY_EXIT (p == NULL);
+  call_count++;
+
+  p = calloc (512, 1);
+  TEST_VERIFY_EXIT (p != NULL);
+  call_count++;
+
+  free (p);
+  call_count++;
+
+  p = memalign (0x100, 0x100);
+  TEST_VERIFY_EXIT (p != NULL);
+  call_count++;
+
+  free (p);
+  call_count++;
+
+  printf ("call_count: %d, hook_count: %d\n", call_count, hook_count);
+
+#ifdef HOOKS_ENABLED
+  TEST_VERIFY_EXIT (call_count == hook_count);
+#else
+  TEST_VERIFY_EXIT (hook_count == 0);
+#endif
+
+  exit (0);
+}
+
+#include <support/test-driver.c>
diff --git a/malloc/tst-compathooks-on.c b/malloc/tst-compathooks-on.c
new file mode 100644
index 0000000000..4da183687a
--- /dev/null
+++ b/malloc/tst-compathooks-on.c
@@ -0,0 +1,2 @@ 
+#define HOOKS_ENABLED 1
+#include "tst-compathooks-off.c"
diff --git a/malloc/tst-malloc-usable-static-tunables.c b/malloc/tst-malloc-usable-static-tunables.c
deleted file mode 100644
index 8907db01a5..0000000000
--- a/malloc/tst-malloc-usable-static-tunables.c
+++ /dev/null
@@ -1 +0,0 @@ 
-#include <malloc/tst-malloc-usable.c>
diff --git a/malloc/tst-malloc-usable-static.c b/malloc/tst-malloc-usable-static.c
deleted file mode 100644
index 8907db01a5..0000000000
--- a/malloc/tst-malloc-usable-static.c
+++ /dev/null
@@ -1 +0,0 @@ 
-#include <malloc/tst-malloc-usable.c>
diff --git a/malloc/tst-mtrace.sh b/malloc/tst-mtrace.sh
index 9295683aff..a830204d5e 100755
--- a/malloc/tst-mtrace.sh
+++ b/malloc/tst-mtrace.sh
@@ -30,6 +30,7 @@  trap "rm -f ${common_objpfx}malloc/tst-mtrace.leak; exit 1" 1 2 15
 ${test_program_prefix_before_env} \
 ${run_program_env} \
 MALLOC_TRACE=${common_objpfx}malloc/tst-mtrace.leak \
+LD_PRELOAD=${common_objpfx}malloc/libc_malloc_debug.so \
 ${test_program_prefix_after_env} \
   ${common_objpfx}malloc/tst-mtrace || status=1
 
diff --git a/manual/memory.texi b/manual/memory.texi
index 31ee36be8c..93305f289b 100644
--- a/manual/memory.texi
+++ b/manual/memory.texi
@@ -1256,8 +1256,9 @@  environment variable @env{MALLOC_ARENA_MAX} to the desired value.
 @cindex consistency checking, of heap
 
 You can ask @code{malloc} to check the consistency of dynamic memory by
-using the @code{mcheck} function.  This function is a GNU extension,
-declared in @file{mcheck.h}.
+using the @code{mcheck} function and preloading the malloc debug library
+@file{libc_malloc_debug.so} using the @var{LD_PRELOAD} environment variable.
+This function is a GNU extension, declared in @file{mcheck.h}.
 @pindex mcheck.h
 
 @deftypefun int mcheck (void (*@var{abortfn}) (enum mcheck_status @var{status}))
@@ -1368,7 +1369,10 @@  non-zero value less than 4, a special (less efficient) implementation is
 used which is designed to be tolerant against simple errors, such as
 double calls of @code{free} with the same argument, or overruns of a
 single byte (off-by-one bugs).  Not all such errors can be protected
-against, however, and memory leaks can result.
+against, however, and memory leaks can result.  Like in the case of
+@code{mcheck}, one would need to preload the @file{libc_malloc_debug.so}
+library to enable @code{MALLOC_CHECK_} functionality.  Without this
+preloaded library, setting @code{MALLOC_CHECK_} will have no effect.
 
 Any detected heap corruption results in immediate termination of the
 process.
@@ -1747,6 +1751,12 @@  penalties for the program if the debugging mode is not enabled.
 @c  fprintf dup (on newly-created stream) @aculock
 @c  __cxa_atexit (once) dup @asulock @aculock @acsmem
 @c  free dup @ascuheap @acsmem
+The @code{mtrace} function provides a way to trace memory allocation
+events in the program that calls it.  It is disabled by default in the
+library and can be enabled by preloading the debugging library
+@file{libc_malloc_debug.so} using the @code{LD_PRELOAD} environment
+variable.
+
 When the @code{mtrace} function is called it looks for an environment
 variable named @code{MALLOC_TRACE}.  This variable is supposed to
 contain a valid file name.  The user must have write access.  If the
diff --git a/manual/tunables.texi b/manual/tunables.texi
index ebdb562e36..e264e9150c 100644
--- a/manual/tunables.texi
+++ b/manual/tunables.texi
@@ -113,7 +113,9 @@  following tunables in the @code{malloc} namespace:
 
 @deftp Tunable glibc.malloc.check
 This tunable supersedes the @env{MALLOC_CHECK_} environment variable and is
-identical in features.
+identical in features. This tunable has no effect by default and needs the
+debug library @file{libc_malloc_debug.so} to be preloaded using the
+@code{LD_PRELOAD} environment variable.
 
 Setting this tunable to a non-zero value less than 4 enables a special (less
 efficient) memory allocator for the @code{malloc} family of functions that is
diff --git a/misc/Makefile b/misc/Makefile
index ae03e26f1b..b144a3df6c 100644
--- a/misc/Makefile
+++ b/misc/Makefile
@@ -152,13 +152,15 @@  $(objpfx)libg.a: $(dep-dummy-lib); $(make-dummy-lib)
 
 $(objpfx)tst-tsearch: $(libm)
 
-tst-error1-ENV = MALLOC_TRACE=$(objpfx)tst-error1.mtrace
+tst-error1-ENV = MALLOC_TRACE=$(objpfx)tst-error1.mtrace \
+		 LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
 tst-error1-ARGS = $(objpfx)tst-error1.out
 $(objpfx)tst-error1-mem.out: $(objpfx)tst-error1.out
 	$(common-objpfx)malloc/mtrace $(objpfx)tst-error1.mtrace > $@; \
 	$(evaluate-test)
 
-tst-allocate_once-ENV = MALLOC_TRACE=$(objpfx)tst-allocate_once.mtrace
+tst-allocate_once-ENV = MALLOC_TRACE=$(objpfx)tst-allocate_once.mtrace \
+			LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
 $(objpfx)tst-allocate_once-mem.out: $(objpfx)tst-allocate_once.out
 	$(common-objpfx)malloc/mtrace $(objpfx)tst-allocate_once.mtrace > $@; \
 	$(evaluate-test)
diff --git a/nptl/Makefile b/nptl/Makefile
index 9b94bfcd31..ff4d590f11 100644
--- a/nptl/Makefile
+++ b/nptl/Makefile
@@ -494,7 +494,8 @@  CFLAGS-tst-initializers1-gnu11.c += $(CFLAGS-tst-initializers1-<)
 tst-cancel7-ARGS = --command "exec $(host-test-program-cmd)"
 tst-cancelx7-ARGS = $(tst-cancel7-ARGS)
 
-tst-stack3-ENV = MALLOC_TRACE=$(objpfx)tst-stack3.mtrace
+tst-stack3-ENV = MALLOC_TRACE=$(objpfx)tst-stack3.mtrace \
+		 LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
 $(objpfx)tst-stack3-mem.out: $(objpfx)tst-stack3.out
 	$(common-objpfx)malloc/mtrace $(objpfx)tst-stack3.mtrace > $@; \
 	$(evaluate-test)
diff --git a/posix/Makefile b/posix/Makefile
index d82e43eaad..b895638865 100644
--- a/posix/Makefile
+++ b/posix/Makefile
@@ -313,43 +313,50 @@  annexc-CFLAGS = -O
 $(objpfx)annexc: annexc.c
 	$(native-compile)
 
-tst-fnmatch-ENV += MALLOC_TRACE=$(objpfx)tst-fnmatch.mtrace
+tst-fnmatch-ENV += MALLOC_TRACE=$(objpfx)tst-fnmatch.mtrace \
+		   LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
 
 $(objpfx)tst-fnmatch-mem.out: $(objpfx)tst-fnmatch.out
 	$(common-objpfx)malloc/mtrace $(objpfx)tst-fnmatch.mtrace > $@; \
 	$(evaluate-test)
 
-bug-regex2-ENV = MALLOC_TRACE=$(objpfx)bug-regex2.mtrace
+bug-regex2-ENV = MALLOC_TRACE=$(objpfx)bug-regex2.mtrace \
+		 LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
 
 $(objpfx)bug-regex2-mem.out: $(objpfx)bug-regex2.out
 	$(common-objpfx)malloc/mtrace $(objpfx)bug-regex2.mtrace > $@; \
 	$(evaluate-test)
 
-bug-regex14-ENV = MALLOC_TRACE=$(objpfx)bug-regex14.mtrace
+bug-regex14-ENV = MALLOC_TRACE=$(objpfx)bug-regex14.mtrace \
+		  LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
 
 $(objpfx)bug-regex14-mem.out: $(objpfx)bug-regex14.out
 	$(common-objpfx)malloc/mtrace $(objpfx)bug-regex14.mtrace > $@; \
 	$(evaluate-test)
 
-bug-regex21-ENV = MALLOC_TRACE=$(objpfx)bug-regex21.mtrace
+bug-regex21-ENV = MALLOC_TRACE=$(objpfx)bug-regex21.mtrace \
+		  LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
 
 $(objpfx)bug-regex21-mem.out: $(objpfx)bug-regex21.out
 	$(common-objpfx)malloc/mtrace $(objpfx)bug-regex21.mtrace > $@; \
 	$(evaluate-test)
 
-bug-regex31-ENV = MALLOC_TRACE=$(objpfx)bug-regex31.mtrace
+bug-regex31-ENV = MALLOC_TRACE=$(objpfx)bug-regex31.mtrace \
+		  LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
 
 $(objpfx)bug-regex31-mem.out: $(objpfx)bug-regex31.out
 	$(common-objpfx)malloc/mtrace $(objpfx)bug-regex31.mtrace > $@; \
 	$(evaluate-test)
 
-bug-regex36-ENV = MALLOC_TRACE=$(objpfx)bug-regex36.mtrace
+bug-regex36-ENV = MALLOC_TRACE=$(objpfx)bug-regex36.mtrace \
+		  LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
 
 $(objpfx)bug-regex36-mem.out: $(objpfx)bug-regex36.out
 	$(common-objpfx)malloc/mtrace $(objpfx)bug-regex36.mtrace > $@; \
 	$(evaluate-test)
 
-tst-vfork3-ENV = MALLOC_TRACE=$(objpfx)tst-vfork3.mtrace
+tst-vfork3-ENV = MALLOC_TRACE=$(objpfx)tst-vfork3.mtrace \
+		 LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
 
 $(objpfx)tst-vfork3-mem.out: $(objpfx)tst-vfork3.out
 	$(common-objpfx)malloc/mtrace $(objpfx)tst-vfork3.mtrace > $@; \
@@ -358,18 +365,22 @@  $(objpfx)tst-vfork3-mem.out: $(objpfx)tst-vfork3.out
 # tst-rxspencer.mtrace is not generated, only
 # tst-rxspencer-no-utf8.mtrace, since otherwise the file has almost
 # 100M and takes very long time to process.
-tst-rxspencer-no-utf8-ENV += MALLOC_TRACE=$(objpfx)tst-rxspencer-no-utf8.mtrace
+tst-rxspencer-no-utf8-ENV += \
+  MALLOC_TRACE=$(objpfx)tst-rxspencer-no-utf8.mtrace \
+  LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
 $(objpfx)tst-rxspencer-no-utf8-mem.out: $(objpfx)tst-rxspencer-no-utf8.out
 	$(common-objpfx)malloc/mtrace $(objpfx)tst-rxspencer-no-utf8.mtrace \
 				      > $@; \
 	$(evaluate-test)
 
-tst-pcre-ENV = MALLOC_TRACE=$(objpfx)tst-pcre.mtrace
+tst-pcre-ENV = MALLOC_TRACE=$(objpfx)tst-pcre.mtrace \
+	       LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
 $(objpfx)tst-pcre-mem.out: $(objpfx)tst-pcre.out
 	$(common-objpfx)malloc/mtrace $(objpfx)tst-pcre.mtrace > $@; \
 	$(evaluate-test)
 
-tst-boost-ENV = MALLOC_TRACE=$(objpfx)tst-boost.mtrace
+tst-boost-ENV = MALLOC_TRACE=$(objpfx)tst-boost.mtrace \
+		LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
 $(objpfx)tst-boost-mem.out: $(objpfx)tst-boost.out
 	$(common-objpfx)malloc/mtrace $(objpfx)tst-boost.mtrace > $@; \
 	$(evaluate-test)
@@ -384,15 +395,18 @@  $(objpfx)bug-ga2-mem.out: $(objpfx)bug-ga2.out
 	&& $(common-objpfx)malloc/mtrace $(objpfx)bug-ga2.mtrace; } > $@; \
 	$(evaluate-test)
 
-bug-ga2-ENV = MALLOC_TRACE=$(objpfx)bug-ga2.mtrace
+bug-ga2-ENV = MALLOC_TRACE=$(objpfx)bug-ga2.mtrace \
+	      LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
 
-bug-glob2-ENV = MALLOC_TRACE=$(objpfx)bug-glob2.mtrace
+bug-glob2-ENV = MALLOC_TRACE=$(objpfx)bug-glob2.mtrace \
+		LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
 
 $(objpfx)bug-glob2-mem.out: $(objpfx)bug-glob2.out
 	$(common-objpfx)malloc/mtrace $(objpfx)bug-glob2.mtrace > $@; \
 	$(evaluate-test)
 
-tst-glob-tilde-ENV = MALLOC_TRACE=$(objpfx)tst-glob-tilde.mtrace
+tst-glob-tilde-ENV = MALLOC_TRACE=$(objpfx)tst-glob-tilde.mtrace \
+		     LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
 
 $(objpfx)tst-glob-tilde-mem.out: $(objpfx)tst-glob-tilde.out
 	$(common-objpfx)malloc/mtrace $(objpfx)tst-glob-tilde.mtrace > $@; \
diff --git a/resolv/Makefile b/resolv/Makefile
index 31d27454b4..c8721d9e62 100644
--- a/resolv/Makefile
+++ b/resolv/Makefile
@@ -207,19 +207,22 @@  $(objpfx)tst-res_hconf_reorder: $(shared-thread-library)
 tst-res_hconf_reorder-ENV = RESOLV_REORDER=on
 
 $(objpfx)tst-leaks: $(objpfx)libresolv.so
-tst-leaks-ENV = MALLOC_TRACE=$(objpfx)tst-leaks.mtrace
+tst-leaks-ENV = MALLOC_TRACE=$(objpfx)tst-leaks.mtrace \
+		LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
 $(objpfx)mtrace-tst-leaks.out: $(objpfx)tst-leaks.out
 	$(common-objpfx)malloc/mtrace $(objpfx)tst-leaks.mtrace > $@; \
 	$(evaluate-test)
 
-tst-leaks2-ENV = MALLOC_TRACE=$(objpfx)tst-leaks2.mtrace
+tst-leaks2-ENV = MALLOC_TRACE=$(objpfx)tst-leaks2.mtrace \
+		 LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
 $(objpfx)mtrace-tst-leaks2.out: $(objpfx)tst-leaks2.out
 	{ test -r $(objpfx)tst-leaks2.mtrace \
 	|| ( echo "tst-leaks2.mtrace does not exist"; exit 77; ) \
 	&& $(common-objpfx)malloc/mtrace $(objpfx)tst-leaks2.mtrace; } > $@; \
 	$(evaluate-test)
 
-tst-resolv-res_ninit-ENV = MALLOC_TRACE=$(objpfx)tst-resolv-res_ninit.mtrace
+tst-resolv-res_ninit-ENV = MALLOC_TRACE=$(objpfx)tst-resolv-res_ninit.mtrace \
+			LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
 $(objpfx)mtrace-tst-resolv-res_ninit.out: $(objpfx)tst-resolv-res_ninit.out
 	$(common-objpfx)malloc/mtrace \
 	  $(objpfx)tst-resolv-res_ninit.mtrace > $@; \
diff --git a/shlib-versions b/shlib-versions
index edabba08eb..df6603e699 100644
--- a/shlib-versions
+++ b/shlib-versions
@@ -73,3 +73,6 @@  libgcc_s=1
 
 # The vector math library
 libmvec=1
+
+# The malloc debug library
+libc_malloc_debug=0
diff --git a/stdio-common/Makefile b/stdio-common/Makefile
index f87796a8ce..803f16dae0 100644
--- a/stdio-common/Makefile
+++ b/stdio-common/Makefile
@@ -110,15 +110,20 @@  $(objpfx)tst-swprintf.out: $(gen-locales)
 $(objpfx)tst-vfprintf-mbs-prec.out: $(gen-locales)
 endif
 
-tst-printf-bz18872-ENV = MALLOC_TRACE=$(objpfx)tst-printf-bz18872.mtrace
+tst-printf-bz18872-ENV = MALLOC_TRACE=$(objpfx)tst-printf-bz18872.mtrace \
+			LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
 tst-vfprintf-width-prec-ENV = \
-  MALLOC_TRACE=$(objpfx)tst-vfprintf-width-prec.mtrace
+  MALLOC_TRACE=$(objpfx)tst-vfprintf-width-prec.mtrace \
+  LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
 tst-printf-bz25691-ENV = \
-  MALLOC_TRACE=$(objpfx)tst-printf-bz25691.mtrace
+  MALLOC_TRACE=$(objpfx)tst-printf-bz25691.mtrace \
+  LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
 tst-printf-fp-free-ENV = \
-  MALLOC_TRACE=$(objpfx)tst-printf-fp-free.mtrace
+  MALLOC_TRACE=$(objpfx)tst-printf-fp-free.mtrace \
+  LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
 tst-printf-fp-leak-ENV = \
-  MALLOC_TRACE=$(objpfx)tst-printf-fp-leak.mtrace
+  MALLOC_TRACE=$(objpfx)tst-printf-fp-leak.mtrace \
+  LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
 
 $(objpfx)tst-unbputc.out: tst-unbputc.sh $(objpfx)tst-unbputc
 	$(SHELL) $< $(common-objpfx) '$(test-program-prefix)'; \
diff --git a/sysdeps/generic/libc_malloc_debug.abilist b/sysdeps/generic/libc_malloc_debug.abilist
new file mode 100644
index 0000000000..e69de29bb2
diff --git a/sysdeps/mach/hurd/Makefile b/sysdeps/mach/hurd/Makefile
index 46bd7b4600..17bb643c18 100644
--- a/sysdeps/mach/hurd/Makefile
+++ b/sysdeps/mach/hurd/Makefile
@@ -222,5 +222,6 @@  CFLAGS-ypclnt.c += -DUSE_BINDINGDIR=1
 endif
 
 LDLIBS-pthread.so += $(objdir)/hurd/libhurduser.so
+LDLIBS-c_malloc_debug.so += $(link-rpcuserlibs)
 
 endif	# in-Makerules
diff --git a/sysdeps/mach/hurd/i386/libc_malloc_debug.abilist b/sysdeps/mach/hurd/i386/libc_malloc_debug.abilist
new file mode 100644
index 0000000000..393ef2acd7
--- /dev/null
+++ b/sysdeps/mach/hurd/i386/libc_malloc_debug.abilist
@@ -0,0 +1,9 @@ 
+GLIBC_2.16 aligned_alloc F
+GLIBC_2.2.6 calloc F
+GLIBC_2.2.6 free F
+GLIBC_2.2.6 malloc F
+GLIBC_2.2.6 memalign F
+GLIBC_2.2.6 posix_memalign F
+GLIBC_2.2.6 pvalloc F
+GLIBC_2.2.6 realloc F
+GLIBC_2.2.6 valloc F
diff --git a/sysdeps/pthread/Makefile b/sysdeps/pthread/Makefile
index 9b862b93c4..42f9fc5072 100644
--- a/sysdeps/pthread/Makefile
+++ b/sysdeps/pthread/Makefile
@@ -211,7 +211,8 @@  tst-umask1-ARGS = $(objpfx)tst-umask1.temp
 
 $(objpfx)tst-atfork2: $(shared-thread-library)
 LDFLAGS-tst-atfork2 = -rdynamic
-tst-atfork2-ENV = MALLOC_TRACE=$(objpfx)tst-atfork2.mtrace
+tst-atfork2-ENV = MALLOC_TRACE=$(objpfx)tst-atfork2.mtrace \
+		  LD_PRELOAD=$(common-objpfx)/malloc/libc_malloc_debug.so
 $(objpfx)tst-atfork2mod.so: $(shared-thread-library)
 
 ifeq ($(build-shared),yes)
diff --git a/sysdeps/unix/sysv/linux/aarch64/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/aarch64/libc_malloc_debug.abilist
new file mode 100644
index 0000000000..2b183c90d4
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/aarch64/libc_malloc_debug.abilist
@@ -0,0 +1,9 @@ 
+GLIBC_2.17 aligned_alloc F
+GLIBC_2.17 calloc F
+GLIBC_2.17 free F
+GLIBC_2.17 malloc F
+GLIBC_2.17 memalign F
+GLIBC_2.17 posix_memalign F
+GLIBC_2.17 pvalloc F
+GLIBC_2.17 realloc F
+GLIBC_2.17 valloc F
diff --git a/sysdeps/unix/sysv/linux/alpha/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/alpha/libc_malloc_debug.abilist
new file mode 100644
index 0000000000..7621d1266e
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/alpha/libc_malloc_debug.abilist
@@ -0,0 +1,9 @@ 
+GLIBC_2.0 calloc F
+GLIBC_2.0 free F
+GLIBC_2.0 malloc F
+GLIBC_2.0 memalign F
+GLIBC_2.0 pvalloc F
+GLIBC_2.0 realloc F
+GLIBC_2.0 valloc F
+GLIBC_2.16 aligned_alloc F
+GLIBC_2.2 posix_memalign F
diff --git a/sysdeps/unix/sysv/linux/arc/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/arc/libc_malloc_debug.abilist
new file mode 100644
index 0000000000..3ec745c9ac
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/arc/libc_malloc_debug.abilist
@@ -0,0 +1,9 @@ 
+GLIBC_2.32 aligned_alloc F
+GLIBC_2.32 calloc F
+GLIBC_2.32 free F
+GLIBC_2.32 malloc F
+GLIBC_2.32 memalign F
+GLIBC_2.32 posix_memalign F
+GLIBC_2.32 pvalloc F
+GLIBC_2.32 realloc F
+GLIBC_2.32 valloc F
diff --git a/sysdeps/unix/sysv/linux/arm/be/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/arm/be/libc_malloc_debug.abilist
new file mode 100644
index 0000000000..f7938d075f
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/arm/be/libc_malloc_debug.abilist
@@ -0,0 +1,9 @@ 
+GLIBC_2.16 aligned_alloc F
+GLIBC_2.4 calloc F
+GLIBC_2.4 free F
+GLIBC_2.4 malloc F
+GLIBC_2.4 memalign F
+GLIBC_2.4 posix_memalign F
+GLIBC_2.4 pvalloc F
+GLIBC_2.4 realloc F
+GLIBC_2.4 valloc F
diff --git a/sysdeps/unix/sysv/linux/arm/le/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/arm/le/libc_malloc_debug.abilist
new file mode 100644
index 0000000000..f7938d075f
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/arm/le/libc_malloc_debug.abilist
@@ -0,0 +1,9 @@ 
+GLIBC_2.16 aligned_alloc F
+GLIBC_2.4 calloc F
+GLIBC_2.4 free F
+GLIBC_2.4 malloc F
+GLIBC_2.4 memalign F
+GLIBC_2.4 posix_memalign F
+GLIBC_2.4 pvalloc F
+GLIBC_2.4 realloc F
+GLIBC_2.4 valloc F
diff --git a/sysdeps/unix/sysv/linux/csky/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/csky/libc_malloc_debug.abilist
new file mode 100644
index 0000000000..54da2c3e38
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/csky/libc_malloc_debug.abilist
@@ -0,0 +1,9 @@ 
+GLIBC_2.29 aligned_alloc F
+GLIBC_2.29 calloc F
+GLIBC_2.29 free F
+GLIBC_2.29 malloc F
+GLIBC_2.29 memalign F
+GLIBC_2.29 posix_memalign F
+GLIBC_2.29 pvalloc F
+GLIBC_2.29 realloc F
+GLIBC_2.29 valloc F
diff --git a/sysdeps/unix/sysv/linux/hppa/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/hppa/libc_malloc_debug.abilist
new file mode 100644
index 0000000000..3ea834d9a2
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/hppa/libc_malloc_debug.abilist
@@ -0,0 +1,9 @@ 
+GLIBC_2.16 aligned_alloc F
+GLIBC_2.2 calloc F
+GLIBC_2.2 free F
+GLIBC_2.2 malloc F
+GLIBC_2.2 memalign F
+GLIBC_2.2 posix_memalign F
+GLIBC_2.2 pvalloc F
+GLIBC_2.2 realloc F
+GLIBC_2.2 valloc F
diff --git a/sysdeps/unix/sysv/linux/hppa/shlib-versions b/sysdeps/unix/sysv/linux/hppa/shlib-versions
index 3a2d496220..7818a32cc4 100644
--- a/sysdeps/unix/sysv/linux/hppa/shlib-versions
+++ b/sysdeps/unix/sysv/linux/hppa/shlib-versions
@@ -7,3 +7,5 @@  ld=ld.so.1		GLIBC_2.2
 libBrokenLocale=1	GLIBC_2.2
 
 libpthread=0		GLIBC_2.2
+
+libc_malloc_debug=0	GLIBC_2.2
diff --git a/sysdeps/unix/sysv/linux/i386/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/i386/libc_malloc_debug.abilist
new file mode 100644
index 0000000000..7621d1266e
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/i386/libc_malloc_debug.abilist
@@ -0,0 +1,9 @@ 
+GLIBC_2.0 calloc F
+GLIBC_2.0 free F
+GLIBC_2.0 malloc F
+GLIBC_2.0 memalign F
+GLIBC_2.0 pvalloc F
+GLIBC_2.0 realloc F
+GLIBC_2.0 valloc F
+GLIBC_2.16 aligned_alloc F
+GLIBC_2.2 posix_memalign F
diff --git a/sysdeps/unix/sysv/linux/ia64/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/ia64/libc_malloc_debug.abilist
new file mode 100644
index 0000000000..3ea834d9a2
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/ia64/libc_malloc_debug.abilist
@@ -0,0 +1,9 @@ 
+GLIBC_2.16 aligned_alloc F
+GLIBC_2.2 calloc F
+GLIBC_2.2 free F
+GLIBC_2.2 malloc F
+GLIBC_2.2 memalign F
+GLIBC_2.2 posix_memalign F
+GLIBC_2.2 pvalloc F
+GLIBC_2.2 realloc F
+GLIBC_2.2 valloc F
diff --git a/sysdeps/unix/sysv/linux/ia64/shlib-versions b/sysdeps/unix/sysv/linux/ia64/shlib-versions
index 37374c0e20..f57e5bae5e 100644
--- a/sysdeps/unix/sysv/linux/ia64/shlib-versions
+++ b/sysdeps/unix/sysv/linux/ia64/shlib-versions
@@ -6,3 +6,5 @@  ld=ld-linux-ia64.so.2	GLIBC_2.2
 libBrokenLocale=1	GLIBC_2.2
 
 libpthread=0		GLIBC_2.2
+
+libc_malloc_debug=0	GLIBC_2.2
diff --git a/sysdeps/unix/sysv/linux/m68k/coldfire/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/m68k/coldfire/libc_malloc_debug.abilist
new file mode 100644
index 0000000000..f7938d075f
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/m68k/coldfire/libc_malloc_debug.abilist
@@ -0,0 +1,9 @@ 
+GLIBC_2.16 aligned_alloc F
+GLIBC_2.4 calloc F
+GLIBC_2.4 free F
+GLIBC_2.4 malloc F
+GLIBC_2.4 memalign F
+GLIBC_2.4 posix_memalign F
+GLIBC_2.4 pvalloc F
+GLIBC_2.4 realloc F
+GLIBC_2.4 valloc F
diff --git a/sysdeps/unix/sysv/linux/m68k/m680x0/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/m68k/m680x0/libc_malloc_debug.abilist
new file mode 100644
index 0000000000..7621d1266e
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/m68k/m680x0/libc_malloc_debug.abilist
@@ -0,0 +1,9 @@ 
+GLIBC_2.0 calloc F
+GLIBC_2.0 free F
+GLIBC_2.0 malloc F
+GLIBC_2.0 memalign F
+GLIBC_2.0 pvalloc F
+GLIBC_2.0 realloc F
+GLIBC_2.0 valloc F
+GLIBC_2.16 aligned_alloc F
+GLIBC_2.2 posix_memalign F
diff --git a/sysdeps/unix/sysv/linux/microblaze/be/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/microblaze/be/libc_malloc_debug.abilist
new file mode 100644
index 0000000000..d02da8ef66
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/microblaze/be/libc_malloc_debug.abilist
@@ -0,0 +1,9 @@ 
+GLIBC_2.18 aligned_alloc F
+GLIBC_2.18 calloc F
+GLIBC_2.18 free F
+GLIBC_2.18 malloc F
+GLIBC_2.18 memalign F
+GLIBC_2.18 posix_memalign F
+GLIBC_2.18 pvalloc F
+GLIBC_2.18 realloc F
+GLIBC_2.18 valloc F
diff --git a/sysdeps/unix/sysv/linux/microblaze/le/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/microblaze/le/libc_malloc_debug.abilist
new file mode 100644
index 0000000000..d02da8ef66
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/microblaze/le/libc_malloc_debug.abilist
@@ -0,0 +1,9 @@ 
+GLIBC_2.18 aligned_alloc F
+GLIBC_2.18 calloc F
+GLIBC_2.18 free F
+GLIBC_2.18 malloc F
+GLIBC_2.18 memalign F
+GLIBC_2.18 posix_memalign F
+GLIBC_2.18 pvalloc F
+GLIBC_2.18 realloc F
+GLIBC_2.18 valloc F
diff --git a/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc_malloc_debug.abilist
new file mode 100644
index 0000000000..7621d1266e
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/mips/mips32/fpu/libc_malloc_debug.abilist
@@ -0,0 +1,9 @@ 
+GLIBC_2.0 calloc F
+GLIBC_2.0 free F
+GLIBC_2.0 malloc F
+GLIBC_2.0 memalign F
+GLIBC_2.0 pvalloc F
+GLIBC_2.0 realloc F
+GLIBC_2.0 valloc F
+GLIBC_2.16 aligned_alloc F
+GLIBC_2.2 posix_memalign F
diff --git a/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc_malloc_debug.abilist
new file mode 100644
index 0000000000..7621d1266e
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc_malloc_debug.abilist
@@ -0,0 +1,9 @@ 
+GLIBC_2.0 calloc F
+GLIBC_2.0 free F
+GLIBC_2.0 malloc F
+GLIBC_2.0 memalign F
+GLIBC_2.0 pvalloc F
+GLIBC_2.0 realloc F
+GLIBC_2.0 valloc F
+GLIBC_2.16 aligned_alloc F
+GLIBC_2.2 posix_memalign F
diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n32/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/mips/mips64/n32/libc_malloc_debug.abilist
new file mode 100644
index 0000000000..7621d1266e
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/mips/mips64/n32/libc_malloc_debug.abilist
@@ -0,0 +1,9 @@ 
+GLIBC_2.0 calloc F
+GLIBC_2.0 free F
+GLIBC_2.0 malloc F
+GLIBC_2.0 memalign F
+GLIBC_2.0 pvalloc F
+GLIBC_2.0 realloc F
+GLIBC_2.0 valloc F
+GLIBC_2.16 aligned_alloc F
+GLIBC_2.2 posix_memalign F
diff --git a/sysdeps/unix/sysv/linux/mips/mips64/n64/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/mips/mips64/n64/libc_malloc_debug.abilist
new file mode 100644
index 0000000000..7621d1266e
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/mips/mips64/n64/libc_malloc_debug.abilist
@@ -0,0 +1,9 @@ 
+GLIBC_2.0 calloc F
+GLIBC_2.0 free F
+GLIBC_2.0 malloc F
+GLIBC_2.0 memalign F
+GLIBC_2.0 pvalloc F
+GLIBC_2.0 realloc F
+GLIBC_2.0 valloc F
+GLIBC_2.16 aligned_alloc F
+GLIBC_2.2 posix_memalign F
diff --git a/sysdeps/unix/sysv/linux/mips/shlib-versions b/sysdeps/unix/sysv/linux/mips/shlib-versions
index ecfe1845f4..c57674deec 100644
--- a/sysdeps/unix/sysv/linux/mips/shlib-versions
+++ b/sysdeps/unix/sysv/linux/mips/shlib-versions
@@ -23,3 +23,5 @@  libnsl=1		GLIBC_2.0 GLIBC_2.2
 librt=1			GLIBC_2.0 GLIBC_2.2
 
 libpthread=0		GLIBC_2.0 GLIBC_2.2
+
+libc_malloc_debug=0	GLIBC_2.0 GLIBC_2.2
diff --git a/sysdeps/unix/sysv/linux/nios2/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/nios2/libc_malloc_debug.abilist
new file mode 100644
index 0000000000..658c965b08
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/nios2/libc_malloc_debug.abilist
@@ -0,0 +1,9 @@ 
+GLIBC_2.21 aligned_alloc F
+GLIBC_2.21 calloc F
+GLIBC_2.21 free F
+GLIBC_2.21 malloc F
+GLIBC_2.21 memalign F
+GLIBC_2.21 posix_memalign F
+GLIBC_2.21 pvalloc F
+GLIBC_2.21 realloc F
+GLIBC_2.21 valloc F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc_malloc_debug.abilist
new file mode 100644
index 0000000000..7621d1266e
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc_malloc_debug.abilist
@@ -0,0 +1,9 @@ 
+GLIBC_2.0 calloc F
+GLIBC_2.0 free F
+GLIBC_2.0 malloc F
+GLIBC_2.0 memalign F
+GLIBC_2.0 pvalloc F
+GLIBC_2.0 realloc F
+GLIBC_2.0 valloc F
+GLIBC_2.16 aligned_alloc F
+GLIBC_2.2 posix_memalign F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc_malloc_debug.abilist
new file mode 100644
index 0000000000..7621d1266e
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc_malloc_debug.abilist
@@ -0,0 +1,9 @@ 
+GLIBC_2.0 calloc F
+GLIBC_2.0 free F
+GLIBC_2.0 malloc F
+GLIBC_2.0 memalign F
+GLIBC_2.0 pvalloc F
+GLIBC_2.0 realloc F
+GLIBC_2.0 valloc F
+GLIBC_2.16 aligned_alloc F
+GLIBC_2.2 posix_memalign F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/be/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc64/be/libc_malloc_debug.abilist
new file mode 100644
index 0000000000..921079580c
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/be/libc_malloc_debug.abilist
@@ -0,0 +1,9 @@ 
+GLIBC_2.16 aligned_alloc F
+GLIBC_2.3 calloc F
+GLIBC_2.3 free F
+GLIBC_2.3 malloc F
+GLIBC_2.3 memalign F
+GLIBC_2.3 posix_memalign F
+GLIBC_2.3 pvalloc F
+GLIBC_2.3 realloc F
+GLIBC_2.3 valloc F
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libc_malloc_debug.abilist
new file mode 100644
index 0000000000..2b183c90d4
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/le/libc_malloc_debug.abilist
@@ -0,0 +1,9 @@ 
+GLIBC_2.17 aligned_alloc F
+GLIBC_2.17 calloc F
+GLIBC_2.17 free F
+GLIBC_2.17 malloc F
+GLIBC_2.17 memalign F
+GLIBC_2.17 posix_memalign F
+GLIBC_2.17 pvalloc F
+GLIBC_2.17 realloc F
+GLIBC_2.17 valloc F
diff --git a/sysdeps/unix/sysv/linux/riscv/rv32/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/riscv/rv32/libc_malloc_debug.abilist
new file mode 100644
index 0000000000..05c8ba8c9f
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/riscv/rv32/libc_malloc_debug.abilist
@@ -0,0 +1,9 @@ 
+GLIBC_2.33 aligned_alloc F
+GLIBC_2.33 calloc F
+GLIBC_2.33 free F
+GLIBC_2.33 malloc F
+GLIBC_2.33 memalign F
+GLIBC_2.33 posix_memalign F
+GLIBC_2.33 pvalloc F
+GLIBC_2.33 realloc F
+GLIBC_2.33 valloc F
diff --git a/sysdeps/unix/sysv/linux/riscv/rv64/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/riscv/rv64/libc_malloc_debug.abilist
new file mode 100644
index 0000000000..20531a7372
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/riscv/rv64/libc_malloc_debug.abilist
@@ -0,0 +1,9 @@ 
+GLIBC_2.27 aligned_alloc F
+GLIBC_2.27 calloc F
+GLIBC_2.27 free F
+GLIBC_2.27 malloc F
+GLIBC_2.27 memalign F
+GLIBC_2.27 posix_memalign F
+GLIBC_2.27 pvalloc F
+GLIBC_2.27 realloc F
+GLIBC_2.27 valloc F
diff --git a/sysdeps/unix/sysv/linux/s390/s390-32/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/s390/s390-32/libc_malloc_debug.abilist
new file mode 100644
index 0000000000..7621d1266e
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/s390/s390-32/libc_malloc_debug.abilist
@@ -0,0 +1,9 @@ 
+GLIBC_2.0 calloc F
+GLIBC_2.0 free F
+GLIBC_2.0 malloc F
+GLIBC_2.0 memalign F
+GLIBC_2.0 pvalloc F
+GLIBC_2.0 realloc F
+GLIBC_2.0 valloc F
+GLIBC_2.16 aligned_alloc F
+GLIBC_2.2 posix_memalign F
diff --git a/sysdeps/unix/sysv/linux/s390/s390-64/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/s390/s390-64/libc_malloc_debug.abilist
new file mode 100644
index 0000000000..3ea834d9a2
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/s390/s390-64/libc_malloc_debug.abilist
@@ -0,0 +1,9 @@ 
+GLIBC_2.16 aligned_alloc F
+GLIBC_2.2 calloc F
+GLIBC_2.2 free F
+GLIBC_2.2 malloc F
+GLIBC_2.2 memalign F
+GLIBC_2.2 posix_memalign F
+GLIBC_2.2 pvalloc F
+GLIBC_2.2 realloc F
+GLIBC_2.2 valloc F
diff --git a/sysdeps/unix/sysv/linux/sh/be/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/sh/be/libc_malloc_debug.abilist
new file mode 100644
index 0000000000..3ea834d9a2
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/sh/be/libc_malloc_debug.abilist
@@ -0,0 +1,9 @@ 
+GLIBC_2.16 aligned_alloc F
+GLIBC_2.2 calloc F
+GLIBC_2.2 free F
+GLIBC_2.2 malloc F
+GLIBC_2.2 memalign F
+GLIBC_2.2 posix_memalign F
+GLIBC_2.2 pvalloc F
+GLIBC_2.2 realloc F
+GLIBC_2.2 valloc F
diff --git a/sysdeps/unix/sysv/linux/sh/le/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/sh/le/libc_malloc_debug.abilist
new file mode 100644
index 0000000000..3ea834d9a2
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/sh/le/libc_malloc_debug.abilist
@@ -0,0 +1,9 @@ 
+GLIBC_2.16 aligned_alloc F
+GLIBC_2.2 calloc F
+GLIBC_2.2 free F
+GLIBC_2.2 malloc F
+GLIBC_2.2 memalign F
+GLIBC_2.2 posix_memalign F
+GLIBC_2.2 pvalloc F
+GLIBC_2.2 realloc F
+GLIBC_2.2 valloc F
diff --git a/sysdeps/unix/sysv/linux/sh/shlib-versions b/sysdeps/unix/sysv/linux/sh/shlib-versions
index 9333bbd7a3..3124264300 100644
--- a/sysdeps/unix/sysv/linux/sh/shlib-versions
+++ b/sysdeps/unix/sysv/linux/sh/shlib-versions
@@ -3,3 +3,4 @@  libc=6			GLIBC_2.2
 ld=ld-linux.so.2	GLIBC_2.2
 libBrokenLocale=1	GLIBC_2.2
 libpthread=0		GLIBC_2.2
+libc_malloc_debug=0	GLIBC_2.2
diff --git a/sysdeps/unix/sysv/linux/sparc/sparc32/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/sparc/sparc32/libc_malloc_debug.abilist
new file mode 100644
index 0000000000..7621d1266e
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/sparc/sparc32/libc_malloc_debug.abilist
@@ -0,0 +1,9 @@ 
+GLIBC_2.0 calloc F
+GLIBC_2.0 free F
+GLIBC_2.0 malloc F
+GLIBC_2.0 memalign F
+GLIBC_2.0 pvalloc F
+GLIBC_2.0 realloc F
+GLIBC_2.0 valloc F
+GLIBC_2.16 aligned_alloc F
+GLIBC_2.2 posix_memalign F
diff --git a/sysdeps/unix/sysv/linux/sparc/sparc64/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/sparc/sparc64/libc_malloc_debug.abilist
new file mode 100644
index 0000000000..3ea834d9a2
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/sparc/sparc64/libc_malloc_debug.abilist
@@ -0,0 +1,9 @@ 
+GLIBC_2.16 aligned_alloc F
+GLIBC_2.2 calloc F
+GLIBC_2.2 free F
+GLIBC_2.2 malloc F
+GLIBC_2.2 memalign F
+GLIBC_2.2 posix_memalign F
+GLIBC_2.2 pvalloc F
+GLIBC_2.2 realloc F
+GLIBC_2.2 valloc F
diff --git a/sysdeps/unix/sysv/linux/sparc/sparc64/shlib-versions b/sysdeps/unix/sysv/linux/sparc/sparc64/shlib-versions
index 9333bbd7a3..3124264300 100644
--- a/sysdeps/unix/sysv/linux/sparc/sparc64/shlib-versions
+++ b/sysdeps/unix/sysv/linux/sparc/sparc64/shlib-versions
@@ -3,3 +3,4 @@  libc=6			GLIBC_2.2
 ld=ld-linux.so.2	GLIBC_2.2
 libBrokenLocale=1	GLIBC_2.2
 libpthread=0		GLIBC_2.2
+libc_malloc_debug=0	GLIBC_2.2
diff --git a/sysdeps/unix/sysv/linux/x86_64/64/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/x86_64/64/libc_malloc_debug.abilist
new file mode 100644
index 0000000000..723c5f48f0
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/x86_64/64/libc_malloc_debug.abilist
@@ -0,0 +1,9 @@ 
+GLIBC_2.16 aligned_alloc F
+GLIBC_2.2.5 calloc F
+GLIBC_2.2.5 free F
+GLIBC_2.2.5 malloc F
+GLIBC_2.2.5 memalign F
+GLIBC_2.2.5 posix_memalign F
+GLIBC_2.2.5 pvalloc F
+GLIBC_2.2.5 realloc F
+GLIBC_2.2.5 valloc F
diff --git a/sysdeps/unix/sysv/linux/x86_64/x32/libc_malloc_debug.abilist b/sysdeps/unix/sysv/linux/x86_64/x32/libc_malloc_debug.abilist
new file mode 100644
index 0000000000..c506f45101
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/x86_64/x32/libc_malloc_debug.abilist
@@ -0,0 +1,9 @@ 
+GLIBC_2.16 aligned_alloc F
+GLIBC_2.16 calloc F
+GLIBC_2.16 free F
+GLIBC_2.16 malloc F
+GLIBC_2.16 memalign F
+GLIBC_2.16 posix_memalign F
+GLIBC_2.16 pvalloc F
+GLIBC_2.16 realloc F
+GLIBC_2.16 valloc F