elf: Add <dl-debug.h>

Message ID 20211225202353.789968-1-hjl.tools@gmail.com
State Committed
Headers
Series elf: Add <dl-debug.h> |

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

Commit Message

H.J. Lu Dec. 25, 2021, 8:23 p.m. UTC
  Add <dl-debug.h> to setup debugging entry in PT_DYNAMIC segment to support
DT_DEBUG, DT_MIPS_RLD_MAP_REL and DT_MIPS_RLD_MAP.

Tested on x86-64, x32 and i686 as well as with build-many-glibcs.py.
---
 elf/dl-reloc-static-pie.c  | 11 ++--------
 elf/rtld.c                 | 13 ++++--------
 sysdeps/generic/dl-debug.h | 33 ++++++++++++++++++++++++++++++
 sysdeps/mips/dl-debug.h    | 41 ++++++++++++++++++++++++++++++++++++++
 sysdeps/mips/dl-machine.h  | 15 --------------
 5 files changed, 80 insertions(+), 33 deletions(-)
 create mode 100644 sysdeps/generic/dl-debug.h
 create mode 100644 sysdeps/mips/dl-debug.h
  

Comments

H.J. Lu Jan. 1, 2022, 4:17 p.m. UTC | #1
On Sat, Dec 25, 2021 at 12:23 PM H.J. Lu <hjl.tools@gmail.com> wrote:
>
> Add <dl-debug.h> to setup debugging entry in PT_DYNAMIC segment to support
> DT_DEBUG, DT_MIPS_RLD_MAP_REL and DT_MIPS_RLD_MAP.
>
> Tested on x86-64, x32 and i686 as well as with build-many-glibcs.py.
> ---
>  elf/dl-reloc-static-pie.c  | 11 ++--------
>  elf/rtld.c                 | 13 ++++--------
>  sysdeps/generic/dl-debug.h | 33 ++++++++++++++++++++++++++++++
>  sysdeps/mips/dl-debug.h    | 41 ++++++++++++++++++++++++++++++++++++++
>  sysdeps/mips/dl-machine.h  | 15 --------------
>  5 files changed, 80 insertions(+), 33 deletions(-)
>  create mode 100644 sysdeps/generic/dl-debug.h
>  create mode 100644 sysdeps/mips/dl-debug.h
>
> diff --git a/elf/dl-reloc-static-pie.c b/elf/dl-reloc-static-pie.c
> index 5b85df8a2e..ad91721fe3 100644
> --- a/elf/dl-reloc-static-pie.c
> +++ b/elf/dl-reloc-static-pie.c
> @@ -24,6 +24,7 @@
>  #include <ldsodefs.h>
>
>  #include <dl-machine.h>
> +#include <dl-debug.h>
>
>  #define RESOLVE_MAP(map, scope, sym, version, flags) map
>  #include "dynamic-link.h"
> @@ -68,14 +69,6 @@ _dl_relocate_static_pie (void)
>
>    /* Set up debugging before the debugger is notified for the first
>       time.  */
> -# ifdef ELF_MACHINE_DEBUG_SETUP
> -  /* Some machines (e.g. MIPS) don't use DT_DEBUG in this way.  */
> -  ELF_MACHINE_DEBUG_SETUP (main_map, r);
> -# else
> -  if (main_map->l_info[DT_DEBUG] != NULL)
> -    /* There is a DT_DEBUG entry in the dynamic section.  Fill it in
> -       with the run-time address of the r_debug structure  */
> -    main_map->l_info[DT_DEBUG]->d_un.d_ptr = (ElfW(Addr)) r;
> -# endif
> +  elf_setup_debug_entry (main_map, r);
>  }
>  #endif
> diff --git a/elf/rtld.c b/elf/rtld.c
> index 4b09e84b0d..f75cb37e47 100644
> --- a/elf/rtld.c
> +++ b/elf/rtld.c
> @@ -62,6 +62,9 @@
>  #define RESOLVE_MAP(map, scope, sym, version, flags) map
>  #include "dynamic-link.h"
>
> +/* Must include after <dl-machine.h> for DT_MIPS definition.  */
> +#include <dl-debug.h>
> +
>  /* Only enables rtld profiling for architectures which provides non generic
>     hp-timing support.  The generic support requires either syscall
>     (clock_gettime), which will incur in extra overhead on loading time.
> @@ -1796,15 +1799,7 @@ dl_main (const ElfW(Phdr) *phdr,
>    size_t count_modids = _dl_count_modids ();
>
>    /* Set up debugging before the debugger is notified for the first time.  */
> -#ifdef ELF_MACHINE_DEBUG_SETUP
> -  /* Some machines (e.g. MIPS) don't use DT_DEBUG in this way.  */
> -  ELF_MACHINE_DEBUG_SETUP (main_map, r);
> -#else
> -  if (main_map->l_info[DT_DEBUG] != NULL)
> -    /* There is a DT_DEBUG entry in the dynamic section.  Fill it in
> -       with the run-time address of the r_debug structure  */
> -    main_map->l_info[DT_DEBUG]->d_un.d_ptr = (ElfW(Addr)) r;
> -#endif
> +  elf_setup_debug_entry (main_map, r);
>
>    /* We start adding objects.  */
>    r->r_state = RT_ADD;
> diff --git a/sysdeps/generic/dl-debug.h b/sysdeps/generic/dl-debug.h
> new file mode 100644
> index 0000000000..b492c0bcc6
> --- /dev/null
> +++ b/sysdeps/generic/dl-debug.h
> @@ -0,0 +1,33 @@
> +/* Debugging support.  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/>.  */
> +
> +#ifndef _DL_DEBUG_H
> +#define _DL_DEBUG_H
> +
> +/* There is a DT_DEBUG entry in the dynamic section.  Fill it in with the
> +   run-time address of the r_debug structure  */
> +
> +static inline void
> +__attribute ((always_inline))
> +elf_setup_debug_entry (struct link_map *l, struct r_debug *r)
> +{
> +  if (l->l_info[DT_DEBUG] != NULL)
> +    l->l_info[DT_DEBUG]->d_un.d_ptr = (ElfW(Addr)) r;
> +}
> +
> +#endif /* _DL_DEBUG_H */
> diff --git a/sysdeps/mips/dl-debug.h b/sysdeps/mips/dl-debug.h
> new file mode 100644
> index 0000000000..a4c8d49309
> --- /dev/null
> +++ b/sysdeps/mips/dl-debug.h
> @@ -0,0 +1,41 @@
> +/* Debugging support.  MIPS 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/>.  */
> +
> +#ifndef _DL_DEBUG_H
> +#define _DL_DEBUG_H
> +
> +/* If there is a DT_MIPS_RLD_MAP_REL or DT_MIPS_RLD_MAP entry in the
> +   dynamic section, fill in the debug map pointer with the run-time
> +   address of the r_debug structure.  */
> +
> +static inline void
> +__attribute ((always_inline))
> +elf_setup_debug_entry (struct link_map *l, struct r_debug *r)
> +{
> +  if (l->l_info[DT_MIPS (RLD_MAP_REL)] != NULL)
> +    {
> +      char *ptr = (char *) l->l_info[DT_MIPS (RLD_MAP_REL)];
> +      ptr += l->l_info[DT_MIPS (RLD_MAP_REL)]->d_un.d_val;
> +      *(ElfW(Addr) *) ptr = (ElfW(Addr)) r;
> +    }
> +  else if (l->l_info[DT_MIPS (RLD_MAP)] != NULL)
> +    *(ElfW(Addr) *) (l->l_info[DT_MIPS (RLD_MAP)]->d_un.d_ptr)
> +      = (ElfW(Addr)) r;
> +}
> +
> +#endif /* _DL_DEBUG_H */
> diff --git a/sysdeps/mips/dl-machine.h b/sysdeps/mips/dl-machine.h
> index d7b8341b74..ea8c881807 100644
> --- a/sysdeps/mips/dl-machine.h
> +++ b/sysdeps/mips/dl-machine.h
> @@ -65,21 +65,6 @@
>     in l_info array.  */
>  #define DT_MIPS(x) (DT_MIPS_##x - DT_LOPROC + DT_NUM)
>
> -/* If there is a DT_MIPS_RLD_MAP_REL or DT_MIPS_RLD_MAP entry in the dynamic
> -   section, fill in the debug map pointer with the run-time address of the
> -   r_debug structure.  */
> -#define ELF_MACHINE_DEBUG_SETUP(l,r) \
> -do { if ((l)->l_info[DT_MIPS (RLD_MAP_REL)]) \
> -       { \
> -        char *ptr = (char *)(l)->l_info[DT_MIPS (RLD_MAP_REL)]; \
> -        ptr += (l)->l_info[DT_MIPS (RLD_MAP_REL)]->d_un.d_val; \
> -        *(ElfW(Addr) *)ptr = (ElfW(Addr)) (r); \
> -       } \
> -     else if ((l)->l_info[DT_MIPS (RLD_MAP)]) \
> -       *(ElfW(Addr) *)((l)->l_info[DT_MIPS (RLD_MAP)]->d_un.d_ptr) = \
> -       (ElfW(Addr)) (r); \
> -   } while (0)
> -
>  #if ((defined __mips_nan2008 && !defined HAVE_MIPS_NAN2008) \
>       || (!defined __mips_nan2008 && defined HAVE_MIPS_NAN2008))
>  # error "Configuration inconsistency: __mips_nan2008 != HAVE_MIPS_NAN2008, overridden CFLAGS?"
> --
> 2.33.1
>

If there is no objection, I will check it in on Monday.
  

Patch

diff --git a/elf/dl-reloc-static-pie.c b/elf/dl-reloc-static-pie.c
index 5b85df8a2e..ad91721fe3 100644
--- a/elf/dl-reloc-static-pie.c
+++ b/elf/dl-reloc-static-pie.c
@@ -24,6 +24,7 @@ 
 #include <ldsodefs.h>
 
 #include <dl-machine.h>
+#include <dl-debug.h>
 
 #define RESOLVE_MAP(map, scope, sym, version, flags) map
 #include "dynamic-link.h"
@@ -68,14 +69,6 @@  _dl_relocate_static_pie (void)
 
   /* Set up debugging before the debugger is notified for the first
      time.  */
-# ifdef ELF_MACHINE_DEBUG_SETUP
-  /* Some machines (e.g. MIPS) don't use DT_DEBUG in this way.  */
-  ELF_MACHINE_DEBUG_SETUP (main_map, r);
-# else
-  if (main_map->l_info[DT_DEBUG] != NULL)
-    /* There is a DT_DEBUG entry in the dynamic section.  Fill it in
-       with the run-time address of the r_debug structure  */
-    main_map->l_info[DT_DEBUG]->d_un.d_ptr = (ElfW(Addr)) r;
-# endif
+  elf_setup_debug_entry (main_map, r);
 }
 #endif
diff --git a/elf/rtld.c b/elf/rtld.c
index 4b09e84b0d..f75cb37e47 100644
--- a/elf/rtld.c
+++ b/elf/rtld.c
@@ -62,6 +62,9 @@ 
 #define RESOLVE_MAP(map, scope, sym, version, flags) map
 #include "dynamic-link.h"
 
+/* Must include after <dl-machine.h> for DT_MIPS definition.  */
+#include <dl-debug.h>
+
 /* Only enables rtld profiling for architectures which provides non generic
    hp-timing support.  The generic support requires either syscall
    (clock_gettime), which will incur in extra overhead on loading time.
@@ -1796,15 +1799,7 @@  dl_main (const ElfW(Phdr) *phdr,
   size_t count_modids = _dl_count_modids ();
 
   /* Set up debugging before the debugger is notified for the first time.  */
-#ifdef ELF_MACHINE_DEBUG_SETUP
-  /* Some machines (e.g. MIPS) don't use DT_DEBUG in this way.  */
-  ELF_MACHINE_DEBUG_SETUP (main_map, r);
-#else
-  if (main_map->l_info[DT_DEBUG] != NULL)
-    /* There is a DT_DEBUG entry in the dynamic section.  Fill it in
-       with the run-time address of the r_debug structure  */
-    main_map->l_info[DT_DEBUG]->d_un.d_ptr = (ElfW(Addr)) r;
-#endif
+  elf_setup_debug_entry (main_map, r);
 
   /* We start adding objects.  */
   r->r_state = RT_ADD;
diff --git a/sysdeps/generic/dl-debug.h b/sysdeps/generic/dl-debug.h
new file mode 100644
index 0000000000..b492c0bcc6
--- /dev/null
+++ b/sysdeps/generic/dl-debug.h
@@ -0,0 +1,33 @@ 
+/* Debugging support.  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/>.  */
+
+#ifndef _DL_DEBUG_H
+#define _DL_DEBUG_H
+
+/* There is a DT_DEBUG entry in the dynamic section.  Fill it in with the
+   run-time address of the r_debug structure  */
+
+static inline void
+__attribute ((always_inline))
+elf_setup_debug_entry (struct link_map *l, struct r_debug *r)
+{
+  if (l->l_info[DT_DEBUG] != NULL)
+    l->l_info[DT_DEBUG]->d_un.d_ptr = (ElfW(Addr)) r;
+}
+
+#endif /* _DL_DEBUG_H */
diff --git a/sysdeps/mips/dl-debug.h b/sysdeps/mips/dl-debug.h
new file mode 100644
index 0000000000..a4c8d49309
--- /dev/null
+++ b/sysdeps/mips/dl-debug.h
@@ -0,0 +1,41 @@ 
+/* Debugging support.  MIPS 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/>.  */
+
+#ifndef _DL_DEBUG_H
+#define _DL_DEBUG_H
+
+/* If there is a DT_MIPS_RLD_MAP_REL or DT_MIPS_RLD_MAP entry in the
+   dynamic section, fill in the debug map pointer with the run-time
+   address of the r_debug structure.  */
+
+static inline void
+__attribute ((always_inline))
+elf_setup_debug_entry (struct link_map *l, struct r_debug *r)
+{
+  if (l->l_info[DT_MIPS (RLD_MAP_REL)] != NULL)
+    {
+      char *ptr = (char *) l->l_info[DT_MIPS (RLD_MAP_REL)];
+      ptr += l->l_info[DT_MIPS (RLD_MAP_REL)]->d_un.d_val;
+      *(ElfW(Addr) *) ptr = (ElfW(Addr)) r;
+    }
+  else if (l->l_info[DT_MIPS (RLD_MAP)] != NULL)
+    *(ElfW(Addr) *) (l->l_info[DT_MIPS (RLD_MAP)]->d_un.d_ptr)
+      = (ElfW(Addr)) r;
+}
+
+#endif /* _DL_DEBUG_H */
diff --git a/sysdeps/mips/dl-machine.h b/sysdeps/mips/dl-machine.h
index d7b8341b74..ea8c881807 100644
--- a/sysdeps/mips/dl-machine.h
+++ b/sysdeps/mips/dl-machine.h
@@ -65,21 +65,6 @@ 
    in l_info array.  */
 #define DT_MIPS(x) (DT_MIPS_##x - DT_LOPROC + DT_NUM)
 
-/* If there is a DT_MIPS_RLD_MAP_REL or DT_MIPS_RLD_MAP entry in the dynamic
-   section, fill in the debug map pointer with the run-time address of the
-   r_debug structure.  */
-#define ELF_MACHINE_DEBUG_SETUP(l,r) \
-do { if ((l)->l_info[DT_MIPS (RLD_MAP_REL)]) \
-       { \
-	 char *ptr = (char *)(l)->l_info[DT_MIPS (RLD_MAP_REL)]; \
-	 ptr += (l)->l_info[DT_MIPS (RLD_MAP_REL)]->d_un.d_val; \
-	 *(ElfW(Addr) *)ptr = (ElfW(Addr)) (r); \
-       } \
-     else if ((l)->l_info[DT_MIPS (RLD_MAP)]) \
-       *(ElfW(Addr) *)((l)->l_info[DT_MIPS (RLD_MAP)]->d_un.d_ptr) = \
-       (ElfW(Addr)) (r); \
-   } while (0)
-
 #if ((defined __mips_nan2008 && !defined HAVE_MIPS_NAN2008) \
      || (!defined __mips_nan2008 && defined HAVE_MIPS_NAN2008))
 # error "Configuration inconsistency: __mips_nan2008 != HAVE_MIPS_NAN2008, overridden CFLAGS?"