diff mbox series

[v8,02/10] Remove __after_morecore_hook

Message ID 20210713073845.504356-3-siddhesh@sourceware.org
State Superseded
Headers show
Series malloc hooks removal | expand

Checks

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

Commit Message

Siddhesh Poyarekar July 13, 2021, 7:38 a.m. UTC
Remove __after_morecore_hook from the API and finalize the symbol so
that it can no longer be used in new applications.  Old applications
using __after_morecore_hook will find that their hook is no longer
called.
---
 malloc/hooks.c  |  5 +++++
 malloc/malloc.c | 22 +---------------------
 malloc/malloc.h |  3 ---
 3 files changed, 6 insertions(+), 24 deletions(-)

Comments

Carlos O'Donell July 17, 2021, 10:03 p.m. UTC | #1
On 7/13/21 3:38 AM, Siddhesh Poyarekar wrote:
> Remove __after_morecore_hook from the API and finalize the symbol so
> that it can no longer be used in new applications.  Old applications
> using __after_morecore_hook will find that their hook is no longer
> called.

OK for 2.34.

Tested without regression on x86_64 and i686.

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

> ---
>  malloc/hooks.c  |  5 +++++
>  malloc/malloc.c | 22 +---------------------
>  malloc/malloc.h |  3 ---
>  3 files changed, 6 insertions(+), 24 deletions(-)
> 
> diff --git a/malloc/hooks.c b/malloc/hooks.c
> index daa5c7cfae..45c91d6502 100644
> --- a/malloc/hooks.c
> +++ b/malloc/hooks.c
> @@ -17,6 +17,11 @@
>     License along with the GNU C Library; see the file COPYING.LIB.  If
>     not, see <https://www.gnu.org/licenses/>.  */
>  
> +#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);

OK.

> +#endif
> +
>  /* Hooks for debugging versions.  The initial hooks just call the
>     initialization routine, then do the normal work. */
>  
> diff --git a/malloc/malloc.c b/malloc/malloc.c
> index 154f6b460c..24e7854a0e 100644
> --- a/malloc/malloc.c
> +++ b/malloc/malloc.c
> @@ -2041,8 +2041,6 @@ void *weak_variable (*__realloc_hook)
>  void *weak_variable (*__memalign_hook)
>    (size_t __alignment, size_t __size, const void *)
>    = memalign_hook_ini;
> -void weak_variable (*__after_morecore_hook) (void) = NULL;
> -

OK.

>  /* This function is called from the arena shutdown hook, to free the
>     thread cache (if it exists).  */
>  static void tcache_thread_shutdown (void);
> @@ -2668,14 +2666,7 @@ sysmalloc (INTERNAL_SIZE_T nb, mstate av)
>            LIBC_PROBE (memory_sbrk_more, 2, brk, size);
>          }
>  
> -      if (brk != (char *) (MORECORE_FAILURE))
> -        {
> -          /* Call the `morecore' hook if necessary.  */
> -          void (*hook) (void) = atomic_forced_read (__after_morecore_hook);
> -          if (__builtin_expect (hook != NULL, 0))
> -            (*hook)();
> -        }
> -      else

OK.

> +      if (brk == (char *) (MORECORE_FAILURE))
>          {
>            /*
>               If have mmap, try using it as a backup when MORECORE fails or
> @@ -2814,13 +2805,6 @@ sysmalloc (INTERNAL_SIZE_T nb, mstate av)
>                        correction = 0;
>                        snd_brk = (char *) (MORECORE (0));
>                      }
> -                  else
> -                    {
> -                      /* Call the `morecore' hook if necessary.  */
> -                      void (*hook) (void) = atomic_forced_read (__after_morecore_hook);
> -                      if (__builtin_expect (hook != NULL, 0))
> -                        (*hook)();
> -                    }

OK.

>                  }
>  
>                /* handle non-contiguous cases */
> @@ -2979,10 +2963,6 @@ systrim (size_t pad, mstate av)
>         */
>  
>        MORECORE (-extra);
> -      /* Call the `morecore' hook if necessary.  */
> -      void (*hook) (void) = atomic_forced_read (__after_morecore_hook);
> -      if (__builtin_expect (hook != NULL, 0))
> -        (*hook)();

OK.

>        new_brk = (char *) (MORECORE (0));
>  
>        LIBC_PROBE (memory_sbrk_less, 2, new_brk, extra);
> diff --git a/malloc/malloc.h b/malloc/malloc.h
> index c1c0896d29..634b7db868 100644
> --- a/malloc/malloc.h
> +++ b/malloc/malloc.h
> @@ -179,9 +179,6 @@ extern void *(*__MALLOC_HOOK_VOLATILE __memalign_hook)(size_t __alignment,
>                                                         size_t __size,
>                                                         const void *)
>  __MALLOC_DEPRECATED;
> -extern void (*__MALLOC_HOOK_VOLATILE __after_morecore_hook) (void)
> -  __MALLOC_DEPRECATED;

OK.

> -
>  
>  __END_DECLS
>  #endif /* malloc.h */
>
diff mbox series

Patch

diff --git a/malloc/hooks.c b/malloc/hooks.c
index daa5c7cfae..45c91d6502 100644
--- a/malloc/hooks.c
+++ b/malloc/hooks.c
@@ -17,6 +17,11 @@ 
    License along with the GNU C Library; see the file COPYING.LIB.  If
    not, see <https://www.gnu.org/licenses/>.  */
 
+#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);
+#endif
+
 /* Hooks for debugging versions.  The initial hooks just call the
    initialization routine, then do the normal work. */
 
diff --git a/malloc/malloc.c b/malloc/malloc.c
index 154f6b460c..24e7854a0e 100644
--- a/malloc/malloc.c
+++ b/malloc/malloc.c
@@ -2041,8 +2041,6 @@  void *weak_variable (*__realloc_hook)
 void *weak_variable (*__memalign_hook)
   (size_t __alignment, size_t __size, const void *)
   = memalign_hook_ini;
-void weak_variable (*__after_morecore_hook) (void) = NULL;
-
 /* This function is called from the arena shutdown hook, to free the
    thread cache (if it exists).  */
 static void tcache_thread_shutdown (void);
@@ -2668,14 +2666,7 @@  sysmalloc (INTERNAL_SIZE_T nb, mstate av)
           LIBC_PROBE (memory_sbrk_more, 2, brk, size);
         }
 
-      if (brk != (char *) (MORECORE_FAILURE))
-        {
-          /* Call the `morecore' hook if necessary.  */
-          void (*hook) (void) = atomic_forced_read (__after_morecore_hook);
-          if (__builtin_expect (hook != NULL, 0))
-            (*hook)();
-        }
-      else
+      if (brk == (char *) (MORECORE_FAILURE))
         {
           /*
              If have mmap, try using it as a backup when MORECORE fails or
@@ -2814,13 +2805,6 @@  sysmalloc (INTERNAL_SIZE_T nb, mstate av)
                       correction = 0;
                       snd_brk = (char *) (MORECORE (0));
                     }
-                  else
-                    {
-                      /* Call the `morecore' hook if necessary.  */
-                      void (*hook) (void) = atomic_forced_read (__after_morecore_hook);
-                      if (__builtin_expect (hook != NULL, 0))
-                        (*hook)();
-                    }
                 }
 
               /* handle non-contiguous cases */
@@ -2979,10 +2963,6 @@  systrim (size_t pad, mstate av)
        */
 
       MORECORE (-extra);
-      /* Call the `morecore' hook if necessary.  */
-      void (*hook) (void) = atomic_forced_read (__after_morecore_hook);
-      if (__builtin_expect (hook != NULL, 0))
-        (*hook)();
       new_brk = (char *) (MORECORE (0));
 
       LIBC_PROBE (memory_sbrk_less, 2, new_brk, extra);
diff --git a/malloc/malloc.h b/malloc/malloc.h
index c1c0896d29..634b7db868 100644
--- a/malloc/malloc.h
+++ b/malloc/malloc.h
@@ -179,9 +179,6 @@  extern void *(*__MALLOC_HOOK_VOLATILE __memalign_hook)(size_t __alignment,
                                                        size_t __size,
                                                        const void *)
 __MALLOC_DEPRECATED;
-extern void (*__MALLOC_HOOK_VOLATILE __after_morecore_hook) (void)
-  __MALLOC_DEPRECATED;
-
 
 __END_DECLS
 #endif /* malloc.h */