Hi all:
uclibc seem will set argument *memptr to NULL when posix_memalign[1]
fail, I know it's not specify in most document[1-3],
but other libc (newlib, glibc, musl) implementations are not set it to
NULL if fail and gcc testsuite have 1 test case for that[7], so how
about make uclib consistent to other libc?
the patch attached.
newlib[4]:
int
__posix_memalign (void **memptr, size_t alignment, size_t size)
{
void *mem;
/* Test whether the ALIGNMENT argument is valid. It must be a power
of two multiple of sizeof (void *). */
if (alignment % sizeof (void *) != 0 || (alignment & (alignment - 1)) !=
0)
return EINVAL;
mem = __libc_memalign (alignment, size);
if (mem != NULL) // only set when success
{
*memptr = mem;
return 0;
}
return ENOMEM;
}
glibc [5]:
int
__posix_memalign (void **memptr, size_t alignment, size_t size)
{
void *mem;
/* 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 *)) != 0
|| alignment == 0)
return EINVAL;
/* Call the hook here, so that caller is posix_memalign's caller
and not posix_memalign itself. */
void *(*hook) (size_t, size_t, const void *) =
force_reg (__memalign_hook);
if (__builtin_expect (hook != NULL, 0))
mem = (*hook)(alignment, size, RETURN_ADDRESS (0));
else
mem = __libc_memalign (alignment, size);
if (mem != NULL) { // only set when success
*memptr = mem;
return 0;
}
return ENOMEM;
}
musl [6]:
int posix_memalign(void **res, size_t align, size_t len)
{
if (align < sizeof(void *)) return EINVAL;
void *mem = __memalign(align, len);
if (!mem) return errno;
*res = mem; // only set when success
return 0;
}
[1] http://man7.org/linux/man-pages/man3/posix_memalign.3.html
[2] http://pubs.opengroup.org/onlinepubs/009695399/
functions/posix_memalign.html
[3] https://linux.die.net/man/3/posix_memalign
[4] https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.
git;a=blob;f=newlib/libc/sys/linux/malloc.c;h=25007e8896a1292d6ae821aa35d7b8
973ea99bad;hb=HEAD#l4938
[5] https://sourceware.org/git/?p=glibc.git;a=blob;f=malloc/malloc.c;h=
488579390578e09a1a232ac5161daee086dbbd6b;hb=HEAD#l5086
[6] http://git.musl-libc.org/cgit/musl/tree/src/malloc/posix_memalign.c
[7] https://github.com/gcc-mirror/gcc/blob/master/gcc/testsuite/
gcc.dg/torture/pr60092.c
From a7e46cb115fae7d4de1cedddb0cbf2932b9ddf39 Mon Sep 17 00:00:00 2001
From: Kito Cheng <kito.ch...@gmail.com>
Date: Thu, 23 Feb 2017 17:16:28 +0800
Subject: [PATCH] Only set *memptr when success for posix_memalign
---
libc/stdlib/posix_memalign.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/libc/stdlib/posix_memalign.c b/libc/stdlib/posix_memalign.c
index 523bc2c..0183107 100644
--- a/libc/stdlib/posix_memalign.c
+++ b/libc/stdlib/posix_memalign.c
@@ -34,8 +34,10 @@ int posix_memalign(void **memptr, size_t alignment, size_t size)
|| alignment == 0
*/
return EINVAL;
-
- *memptr = memalign(alignment, size);
-
- return (*memptr != NULL ? 0 : ENOMEM);
+ void *mem = memalign(alignment, size);
+ if (mem != NULL) {
+ *memptr = mem;
+ return 0;
+ } else
+ return ENOMEM;
}
--
2.8.2
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