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author | davidxu <davidxu@FreeBSD.org> | 2014-02-27 02:36:09 +0000 |
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committer | davidxu <davidxu@FreeBSD.org> | 2014-02-27 02:36:09 +0000 |
commit | 3c6681dc2c610038f536ad483a501e35a1a7312c (patch) | |
tree | 27c811097b1e1ebd1b76dac8f1a7de7be6e7aa26 /libexec/rtld-elf | |
parent | 7f44971ec587a3cd596e85ca429d5242a154cb46 (diff) | |
download | FreeBSD-src-3c6681dc2c610038f536ad483a501e35a1a7312c.zip FreeBSD-src-3c6681dc2c610038f536ad483a501e35a1a7312c.tar.gz |
MFC r262277:
malloc_aligned() may not leave enough space for pointer to allocated memory,
saving the pointer will overwrite bytes belongs to another memory block
unexpectly, to fix the problem, use (allocated address + sizeof(void *)) as
initial value, and slip to next aligned address, so maximum extra bytes is
sizeof(void *) + align - 1.
Tested by: Andre Albsmeier < mail at ma17 dot ata dot myota dot orgndre >
MFC r262334:
Increase alignment to size of pointer if the alignment is too small.
Some modules do not align data at least to size of pointer, they uses a
smaller alignment, but our pointer should be aligned to its native
boundary, otherwise on some platforms, hardware alignment checking
will cause bus error.
Diffstat (limited to 'libexec/rtld-elf')
-rw-r--r-- | libexec/rtld-elf/xmalloc.c | 12 |
1 files changed, 5 insertions, 7 deletions
diff --git a/libexec/rtld-elf/xmalloc.c b/libexec/rtld-elf/xmalloc.c index 3b3408c..ed195df 100644 --- a/libexec/rtld-elf/xmalloc.c +++ b/libexec/rtld-elf/xmalloc.c @@ -72,14 +72,12 @@ void * malloc_aligned(size_t size, size_t align) { void *mem, *res; - uintptr_t x; - size_t asize, r; - r = round(sizeof(void *), align); - asize = round(size, align) + r; - mem = xmalloc(asize); - x = (uintptr_t)mem; - res = (void *)round(x, align); + if (align < sizeof(void *)) + align = sizeof(void *); + + mem = xmalloc(size + sizeof(void *) + align - 1); + res = (void *)round((uintptr_t)mem + sizeof(void *), align); *(void **)((uintptr_t)res - sizeof(void *)) = mem; return (res); } |