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am 41ae96a1: am 4bc229eb: am 4449fe96: Merge "Fix 32-bit mmap/mmap64 handling of negative offsets."

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* commit '41ae96a1cc69fd2e1bc39fe55da22f15047beb50':
  Fix 32-bit mmap/mmap64 handling of negative offsets.
This commit is contained in:
Elliott Hughes
2014-01-28 01:18:06 +00:00
committed by Android Git Automerger
parent f025dd96af 41ae96a1cc
commit a873595113
3 changed files with 34 additions and 5 deletions
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8
libc/bionic/mmap.cpp
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@@ -38,14 +38,12 @@ extern "C" void* __mmap2(void*, size_t, int, int, int, size_t);
#define MMAP2_SHIFT 12 // 2**12 == 4096
void* mmap64(void* addr, size_t size, int prot, int flags, int fd, off64_t offset) {
if (offset & ((1UL << MMAP2_SHIFT)-1)) {
if (offset < 0 || (offset & ((1UL << MMAP2_SHIFT)-1)) != 0) {
errno = EINVAL;
return MAP_FAILED;
}
uint64_t unsigned_offset = static_cast<uint64_t>(offset); // To avoid sign extension.
void* result = __mmap2(addr, size, prot, flags, fd, unsigned_offset >> MMAP2_SHIFT);
void* result = __mmap2(addr, size, prot, flags, fd, offset >> MMAP2_SHIFT);
if (result != MAP_FAILED && (flags & (MAP_PRIVATE | MAP_ANONYMOUS)) != 0) {
ErrnoRestorer errno_restorer;
madvise(result, size, MADV_MERGEABLE);
@@ -55,5 +53,5 @@ void* mmap64(void* addr, size_t size, int prot, int flags, int fd, off64_t offse
}
void* mmap(void* addr, size_t size, int prot, int flags, int fd, off_t offset) {
return mmap64(addr, size, prot, flags, fd, static_cast<off64_t>(offset) & 0xffffffff);
return mmap64(addr, size, prot, flags, fd, static_cast<off64_t>(offset));
}