From: Siddhesh Poyarekar via Libc-alpha <libc-alpha@sourceware.org>
To: libc-alpha@sourceware.org
Cc: fweimer@redhat.com
Subject: [PATCH v3 10/10] Remove __morecore and __default_morecore
Date: Fri, 2 Jul 2021 08:05:46 +0530 [thread overview]
Message-ID: <20210702023546.3081774-11-siddhesh@sourceware.org> (raw)
In-Reply-To: <20210702023546.3081774-1-siddhesh@sourceware.org>
Make the __morecore and __default_morecore symbols compat-only and
remove their declarations from the API.
Reviewed-by: DJ Delorie <dj@redhat.com>
---
NEWS | 5 +++++
include/stdlib.h | 3 ---
malloc/arena.c | 12 ++----------
malloc/hooks.c | 3 +++
malloc/malloc-internal.h | 5 +++++
malloc/malloc.c | 4 +---
malloc/malloc.h | 8 --------
malloc/morecore.c | 15 +++++++++++++--
8 files changed, 29 insertions(+), 26 deletions(-)
diff --git a/NEWS b/NEWS
index cebe8384bf..2533919f75 100644
--- a/NEWS
+++ b/NEWS
@@ -106,6 +106,11 @@ Deprecated and removed features, and other changes affecting compatibility:
legacy programs until they are updated to remove references to the memory
allocation hooks.
+* The __morecore and __after_morecore_hook malloc hooks and the default
+ implementation __default_morecore have been removed from the API. Existing
+ applications will continue to link against these symbols but the interfaces
+ no longer have any effect on malloc.
+
Changes to build and runtime requirements:
* On Linux, the shm_open, sem_open, and related functions now expect the
diff --git a/include/stdlib.h b/include/stdlib.h
index 1f6e1508e4..1c6f70b082 100644
--- a/include/stdlib.h
+++ b/include/stdlib.h
@@ -306,9 +306,6 @@ libc_hidden_proto (__qfcvt_r)
# define MB_CUR_MAX (_NL_CURRENT_WORD (LC_CTYPE, _NL_CTYPE_MB_CUR_MAX))
# endif
-extern void *__default_morecore (ptrdiff_t) __THROW;
-libc_hidden_proto (__default_morecore)
-
struct abort_msg_s
{
unsigned int size;
diff --git a/malloc/arena.c b/malloc/arena.c
index 8591c8ea56..00e8b5a32f 100644
--- a/malloc/arena.c
+++ b/malloc/arena.c
@@ -272,14 +272,6 @@ next_env_entry (char ***position)
#endif
-#if defined(SHARED) || defined(USE_MTAG)
-static void *
-__failing_morecore (ptrdiff_t d)
-{
- return (void *) MORECORE_FAILURE;
-}
-#endif
-
#ifdef SHARED
extern struct dl_open_hook *_dl_open_hook;
libc_hidden_proto (_dl_open_hook);
@@ -300,7 +292,7 @@ ptmalloc_init (void)
and that morecore does not support tagged regions, then
disable it. */
if (__MTAG_SBRK_UNTAGGED)
- __morecore = __failing_morecore;
+ __always_fail_morecore = true;
mtag_enabled = true;
mtag_mmap_flags = __MTAG_MMAP_FLAGS;
@@ -313,7 +305,7 @@ ptmalloc_init (void)
generic sbrk implementation also enforces this, but it is not
used on Hurd. */
if (!__libc_initial)
- __morecore = __failing_morecore;
+ __always_fail_morecore = true;
#endif
thread_arena = &main_arena;
diff --git a/malloc/hooks.c b/malloc/hooks.c
index 5e9355761a..b40696c8b7 100644
--- a/malloc/hooks.c
+++ b/malloc/hooks.c
@@ -81,6 +81,9 @@ compat_symbol (libc, __memalign_hook, __memalign_hook, GLIBC_2_0);
void weak_variable (*__after_morecore_hook) (void) = NULL;
compat_symbol (libc, __after_morecore_hook, __after_morecore_hook, GLIBC_2_0);
+void *(*__morecore)(ptrdiff_t);
+compat_symbol (libc, __morecore, __morecore, GLIBC_2_0);
+
/* These hooks will get executed only through the interposed allocator
functions in libmalloc_compathooks. This means that the calls to malloc,
realloc, etc. will lead back into the interposed functions, which is what we
diff --git a/malloc/malloc-internal.h b/malloc/malloc-internal.h
index ee0f5697af..b104f7cdbf 100644
--- a/malloc/malloc-internal.h
+++ b/malloc/malloc-internal.h
@@ -21,6 +21,7 @@
#include <malloc-machine.h>
#include <malloc-sysdep.h>
+#include <stdbool.h>
/* INTERNAL_SIZE_T is the word-size used for internal bookkeeping of
chunk sizes.
@@ -63,6 +64,8 @@
#define top(ar_ptr) ((ar_ptr)->top)
+extern bool __always_fail_morecore attribute_hidden;
+
/* Called in the parent process before a fork. */
void __malloc_fork_lock_parent (void) attribute_hidden;
@@ -78,4 +81,6 @@ void __malloc_arena_thread_freeres (void) attribute_hidden;
/* Activate a standard set of debugging hooks. */
void __malloc_check_init (void) attribute_hidden;
+extern void *__glibc_morecore (ptrdiff_t) attribute_hidden;
+
#endif /* _MALLOC_INTERNAL_H */
diff --git a/malloc/malloc.c b/malloc/malloc.c
index 296e4f9789..79855e93ab 100644
--- a/malloc/malloc.c
+++ b/malloc/malloc.c
@@ -382,10 +382,8 @@ __malloc_assert (const char *assertion, const char *file, unsigned int line,
/* Definition for getting more memory from the OS. */
-#define MORECORE (*__morecore)
+#define MORECORE (*__glibc_morecore)
#define MORECORE_FAILURE 0
-void * __default_morecore (ptrdiff_t);
-void *(*__morecore)(ptrdiff_t) = __default_morecore;
/* Memory tagging. */
diff --git a/malloc/malloc.h b/malloc/malloc.h
index d066a05d82..2df0b38050 100644
--- a/malloc/malloc.h
+++ b/malloc/malloc.h
@@ -76,14 +76,6 @@ extern void *valloc (size_t __size) __THROW __attribute_malloc__
extern void *pvalloc (size_t __size) __THROW __attribute_malloc__
__wur __attr_dealloc_free;
-/* Underlying allocation function; successive calls should return
- contiguous pieces of memory. */
-extern void *(*__morecore) (ptrdiff_t __size) __MALLOC_DEPRECATED;
-
-/* Default value of `__morecore'. */
-extern void *__default_morecore (ptrdiff_t __size)
-__THROW __attribute_malloc__ __MALLOC_DEPRECATED;
-
/* SVID2/XPG mallinfo structure */
struct mallinfo
diff --git a/malloc/morecore.c b/malloc/morecore.c
index 047228779b..c85a85c0eb 100644
--- a/malloc/morecore.c
+++ b/malloc/morecore.c
@@ -38,16 +38,27 @@ libc_hidden_proto (__sbrk)
# define NULL 0
#endif
+#if defined(SHARED) || defined(USE_MTAG)
+bool __always_fail_morecore = false;
+#endif
+
/* Allocate INCREMENT more bytes of data space,
and return the start of data space, or NULL on errors.
If INCREMENT is negative, shrink data space. */
void *
-__default_morecore (ptrdiff_t increment)
+__glibc_morecore (ptrdiff_t increment)
{
+#if defined(SHARED) || defined(USE_MTAG)
+ if (__always_fail_morecore)
+ return NULL;
+#endif
+
void *result = (void *) __sbrk (increment);
if (result == (void *) -1)
return NULL;
return result;
}
-libc_hidden_def (__default_morecore)
+#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_34)
+compat_symbol (libc, __glibc_morecore, __default_morecore, GLIBC_2_0);
+#endif
--
2.31.1
prev parent reply other threads:[~2021-07-02 2:44 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-02 2:35 [PATCH v3 00/10] Remove malloc hooks Siddhesh Poyarekar via Libc-alpha
2021-07-02 2:35 ` [PATCH v3 01/10] mtrace: Deprecate mallwatch and tr_break Siddhesh Poyarekar via Libc-alpha
2021-07-02 2:35 ` [PATCH v3 02/10] Add mcheck tests to malloc Siddhesh Poyarekar via Libc-alpha
2021-07-06 14:50 ` Stefan Liebler via Libc-alpha
2021-07-06 15:54 ` Siddhesh Poyarekar
2021-07-08 23:37 ` H.J. Lu via Libc-alpha
2021-07-09 0:06 ` H.J. Lu via Libc-alpha
2021-07-09 1:46 ` Siddhesh Poyarekar
2021-07-09 3:53 ` [PATCH] Add a generic malloc test for MALLOC_ALIGNMENT H.J. Lu via Libc-alpha
2021-07-09 4:07 ` Siddhesh Poyarekar
2021-07-09 12:24 ` [PATCH v2] " H.J. Lu via Libc-alpha
2021-07-09 13:00 ` Siddhesh Poyarekar
2021-07-09 13:31 ` [PATCH v3] " H.J. Lu via Libc-alpha
2021-07-09 13:34 ` Siddhesh Poyarekar
2021-07-12 18:02 ` [PATCH v3 02/10] Add mcheck tests to malloc Matheus Castanho via Libc-alpha
2021-07-13 1:06 ` Siddhesh Poyarekar
2021-07-13 12:11 ` Matheus Castanho via Libc-alpha
2021-07-02 2:35 ` [PATCH v3 03/10] Move glibc.malloc.check implementation into its own file Siddhesh Poyarekar via Libc-alpha
2021-07-02 9:05 ` Andreas Schwab
2021-07-02 9:29 ` Siddhesh Poyarekar via Libc-alpha
2021-07-02 9:59 ` Andreas Schwab
2021-07-02 2:35 ` [PATCH v3 04/10] malloc: Move malloc hook references to hooks.c Siddhesh Poyarekar via Libc-alpha
2021-07-02 2:35 ` [PATCH v3 05/10] glibc.malloc.check: Wean away from malloc hooks Siddhesh Poyarekar via Libc-alpha
2021-07-02 2:35 ` [PATCH v3 06/10] mcheck: " Siddhesh Poyarekar via Libc-alpha
2021-07-02 2:35 ` [PATCH v3 07/10] mtrace: " Siddhesh Poyarekar via Libc-alpha
2021-07-02 2:35 ` [PATCH v3 08/10] Remove " Siddhesh Poyarekar via Libc-alpha
2021-07-02 2:35 ` [PATCH v3 09/10] Remove __after_morecore_hook Siddhesh Poyarekar via Libc-alpha
2021-07-02 2:35 ` Siddhesh Poyarekar via Libc-alpha [this message]
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