[v3,22/37] elf: Introduce __tls_init_tp for second-phase TCB initialization
Commit Message
TLS_INIT_TP is processor-specific, so it is not a good place to
put thread library initialization code (it would have to be repeated
for all CPUs). Introduce __tls_init_tp as a separate function,
to be called immediately after TLS_INIT_TP. Move the existing
stack list setup code for NPTL to this function.
---
csu/libc-tls.c | 8 +-------
elf/Makefile | 2 +-
elf/dl-tls_init_tp.c | 24 ++++++++++++++++++++++++
elf/rtld.c | 14 ++------------
sysdeps/generic/ldsodefs.h | 5 +++++
sysdeps/nptl/dl-tls_init_tp.c | 30 ++++++++++++++++++++++++++++++
6 files changed, 63 insertions(+), 20 deletions(-)
create mode 100644 elf/dl-tls_init_tp.c
create mode 100644 sysdeps/nptl/dl-tls_init_tp.c
Comments
On 16/03/2021 14:30, Florian Weimer via Libc-alpha wrote:
> TLS_INIT_TP is processor-specific, so it is not a good place to
> put thread library initialization code (it would have to be repeated
> for all CPUs). Introduce __tls_init_tp as a separate function,
> to be called immediately after TLS_INIT_TP. Move the existing
> stack list setup code for NPTL to this function.
LGTM, thanks.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
> ---
> csu/libc-tls.c | 8 +-------
> elf/Makefile | 2 +-
> elf/dl-tls_init_tp.c | 24 ++++++++++++++++++++++++
> elf/rtld.c | 14 ++------------
> sysdeps/generic/ldsodefs.h | 5 +++++
> sysdeps/nptl/dl-tls_init_tp.c | 30 ++++++++++++++++++++++++++++++
> 6 files changed, 63 insertions(+), 20 deletions(-)
> create mode 100644 elf/dl-tls_init_tp.c
> create mode 100644 sysdeps/nptl/dl-tls_init_tp.c
>
> diff --git a/csu/libc-tls.c b/csu/libc-tls.c
> index f3a6a6a075..22f8e4838d 100644
> --- a/csu/libc-tls.c
> +++ b/csu/libc-tls.c
> @@ -24,7 +24,6 @@
> #include <stdio.h>
> #include <sys/param.h>
> #include <array_length.h>
> -#include <list.h>
>
> #ifdef SHARED
> #error makefile bug, this file is for static only
> @@ -193,12 +192,7 @@ __libc_setup_tls (void)
> #endif
> if (__builtin_expect (lossage != NULL, 0))
> _startup_fatal (lossage);
> -
> -#if THREAD_GSCOPE_IN_TCB
> - INIT_LIST_HEAD (&_dl_stack_used);
> - INIT_LIST_HEAD (&_dl_stack_user);
> - list_add (&THREAD_SELF->list, &_dl_stack_user);
> -#endif
> + __tls_init_tp ();
>
> /* Update the executable's link map with enough information to make
> the TLS routines happy. */
Ok.
> diff --git a/elf/Makefile b/elf/Makefile
> index deb76aed99..22b3a06cab 100644
> --- a/elf/Makefile
> +++ b/elf/Makefile
> @@ -35,7 +35,7 @@ dl-routines = $(addprefix dl-,load lookup object reloc deps \
> execstack open close trampoline \
> exception sort-maps lookup-direct \
> call-libc-early-init write \
> - thread_gscope_wait)
> + thread_gscope_wait tls_init_tp)
> ifeq (yes,$(use-ldconfig))
> dl-routines += dl-cache
> endif
Ok.
> diff --git a/elf/dl-tls_init_tp.c b/elf/dl-tls_init_tp.c
> new file mode 100644
> index 0000000000..728cd84c00
> --- /dev/null
> +++ b/elf/dl-tls_init_tp.c
> @@ -0,0 +1,24 @@
> +/* Completion of TCB initialization after TLS_INIT_TP. Generic version.
> + 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 <ldsodefs.h>
> +
> +void
> +__tls_init_tp (void)
> +{
> +}
Ok.
> diff --git a/elf/rtld.c b/elf/rtld.c
> index c2ca4b7ce3..34879016ad 100644
> --- a/elf/rtld.c
> +++ b/elf/rtld.c
> @@ -48,7 +48,6 @@
> #include <array_length.h>
> #include <libc-early-init.h>
> #include <dl-main.h>
> -#include <list.h>
> #include <gnu/lib-names.h>
> #include <dl-tunables.h>
>
> @@ -807,9 +806,7 @@ cannot allocate TLS data structures for initial thread\n");
> const char *lossage = TLS_INIT_TP (tcbp);
> if (__glibc_unlikely (lossage != NULL))
> _dl_fatal_printf ("cannot set up thread-local storage: %s\n", lossage);
> -#if THREAD_GSCOPE_IN_TCB
> - list_add (&THREAD_SELF->list, &GL (dl_stack_user));
> -#endif
> + __tls_init_tp ();
> tls_init_tp_called = true;
>
> return tcbp;
Ok.
> @@ -1150,11 +1147,6 @@ dl_main (const ElfW(Phdr) *phdr,
> GL(dl_rtld_unlock_recursive) = rtld_lock_default_unlock_recursive;
> #endif
>
> -#if THREAD_GSCOPE_IN_TCB
> - INIT_LIST_HEAD (&GL (dl_stack_used));
> - INIT_LIST_HEAD (&GL (dl_stack_user));
> -#endif
> -
> /* The explicit initialization here is cheaper than processing the reloc
> in the _rtld_local definition's initializer. */
Ok.
> GL(dl_make_stack_executable_hook) = &_dl_make_stack_executable;
> @@ -2454,9 +2446,7 @@ dl_main (const ElfW(Phdr) *phdr,
> if (__glibc_unlikely (lossage != NULL))
> _dl_fatal_printf ("cannot set up thread-local storage: %s\n",
> lossage);
> -#if THREAD_GSCOPE_IN_TCB
> - list_add (&THREAD_SELF->list, &GL (dl_stack_user));
> -#endif
> + __tls_init_tp ();
> }
>
> /* Make sure no new search directories have been added. */
Ok.
> diff --git a/sysdeps/generic/ldsodefs.h b/sysdeps/generic/ldsodefs.h
> index dfc117a445..67c6686015 100644
> --- a/sysdeps/generic/ldsodefs.h
> +++ b/sysdeps/generic/ldsodefs.h
> @@ -1163,6 +1163,11 @@ extern void _dl_determine_tlsoffset (void) attribute_hidden;
> number of audit modules are loaded. */
> void _dl_tls_static_surplus_init (size_t naudit) attribute_hidden;
>
> +/* This function is called after processor-specific initialization of
> + the TCB and thread pointer via TLS_INIT_TP, to complete very early
> + initialization of the thread library. */
> +void __tls_init_tp (void) attribute_hidden;
> +
> #ifndef SHARED
> /* Set up the TCB for statically linked applications. This is called
> early during startup because we always use TLS (for errno and the
Ok.
> diff --git a/sysdeps/nptl/dl-tls_init_tp.c b/sysdeps/nptl/dl-tls_init_tp.c
> new file mode 100644
> index 0000000000..8983808233
> --- /dev/null
> +++ b/sysdeps/nptl/dl-tls_init_tp.c
> @@ -0,0 +1,30 @@
> +/* Completion of TCB initialization after TLS_INIT_TP. NPTL version.
> + Copyright (C) 2020-2021 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 <ldsodefs.h>
> +#include <list.h>
> +#include <tls.h>
> +
> +void
> +__tls_init_tp (void)
> +{
> + /* Set up thread stack list management. */
> + INIT_LIST_HEAD (&GL (dl_stack_used));
> + INIT_LIST_HEAD (&GL (dl_stack_user));
> + list_add (&THREAD_SELF->list, &GL (dl_stack_user));
> +}
>
Ok.
@@ -24,7 +24,6 @@
#include <stdio.h>
#include <sys/param.h>
#include <array_length.h>
-#include <list.h>
#ifdef SHARED
#error makefile bug, this file is for static only
@@ -193,12 +192,7 @@ __libc_setup_tls (void)
#endif
if (__builtin_expect (lossage != NULL, 0))
_startup_fatal (lossage);
-
-#if THREAD_GSCOPE_IN_TCB
- INIT_LIST_HEAD (&_dl_stack_used);
- INIT_LIST_HEAD (&_dl_stack_user);
- list_add (&THREAD_SELF->list, &_dl_stack_user);
-#endif
+ __tls_init_tp ();
/* Update the executable's link map with enough information to make
the TLS routines happy. */
@@ -35,7 +35,7 @@ dl-routines = $(addprefix dl-,load lookup object reloc deps \
execstack open close trampoline \
exception sort-maps lookup-direct \
call-libc-early-init write \
- thread_gscope_wait)
+ thread_gscope_wait tls_init_tp)
ifeq (yes,$(use-ldconfig))
dl-routines += dl-cache
endif
new file mode 100644
@@ -0,0 +1,24 @@
+/* Completion of TCB initialization after TLS_INIT_TP. Generic version.
+ 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 <ldsodefs.h>
+
+void
+__tls_init_tp (void)
+{
+}
@@ -48,7 +48,6 @@
#include <array_length.h>
#include <libc-early-init.h>
#include <dl-main.h>
-#include <list.h>
#include <gnu/lib-names.h>
#include <dl-tunables.h>
@@ -807,9 +806,7 @@ cannot allocate TLS data structures for initial thread\n");
const char *lossage = TLS_INIT_TP (tcbp);
if (__glibc_unlikely (lossage != NULL))
_dl_fatal_printf ("cannot set up thread-local storage: %s\n", lossage);
-#if THREAD_GSCOPE_IN_TCB
- list_add (&THREAD_SELF->list, &GL (dl_stack_user));
-#endif
+ __tls_init_tp ();
tls_init_tp_called = true;
return tcbp;
@@ -1150,11 +1147,6 @@ dl_main (const ElfW(Phdr) *phdr,
GL(dl_rtld_unlock_recursive) = rtld_lock_default_unlock_recursive;
#endif
-#if THREAD_GSCOPE_IN_TCB
- INIT_LIST_HEAD (&GL (dl_stack_used));
- INIT_LIST_HEAD (&GL (dl_stack_user));
-#endif
-
/* The explicit initialization here is cheaper than processing the reloc
in the _rtld_local definition's initializer. */
GL(dl_make_stack_executable_hook) = &_dl_make_stack_executable;
@@ -2454,9 +2446,7 @@ dl_main (const ElfW(Phdr) *phdr,
if (__glibc_unlikely (lossage != NULL))
_dl_fatal_printf ("cannot set up thread-local storage: %s\n",
lossage);
-#if THREAD_GSCOPE_IN_TCB
- list_add (&THREAD_SELF->list, &GL (dl_stack_user));
-#endif
+ __tls_init_tp ();
}
/* Make sure no new search directories have been added. */
@@ -1163,6 +1163,11 @@ extern void _dl_determine_tlsoffset (void) attribute_hidden;
number of audit modules are loaded. */
void _dl_tls_static_surplus_init (size_t naudit) attribute_hidden;
+/* This function is called after processor-specific initialization of
+ the TCB and thread pointer via TLS_INIT_TP, to complete very early
+ initialization of the thread library. */
+void __tls_init_tp (void) attribute_hidden;
+
#ifndef SHARED
/* Set up the TCB for statically linked applications. This is called
early during startup because we always use TLS (for errno and the
new file mode 100644
@@ -0,0 +1,30 @@
+/* Completion of TCB initialization after TLS_INIT_TP. NPTL version.
+ Copyright (C) 2020-2021 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 <ldsodefs.h>
+#include <list.h>
+#include <tls.h>
+
+void
+__tls_init_tp (void)
+{
+ /* Set up thread stack list management. */
+ INIT_LIST_HEAD (&GL (dl_stack_used));
+ INIT_LIST_HEAD (&GL (dl_stack_user));
+ list_add (&THREAD_SELF->list, &GL (dl_stack_user));
+}