Merge "Avoid sign extension of the mmap offset."

This commit is contained in:
Elliott Hughes 2013-07-25 17:28:59 +00:00 committed by Gerrit Code Review
commit a9feb5e33a

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@ -37,13 +37,14 @@ extern "C" void* __mmap2(void*, size_t, int, int, int, size_t);
#define MMAP2_SHIFT 12 // 2**12 == 4096
void* mmap(void* addr, size_t size, int prot, int flags, int fd, long offset) {
void* mmap(void* addr, size_t size, int prot, int flags, int fd, off_t offset) {
if (offset & ((1UL << MMAP2_SHIFT)-1)) {
errno = EINVAL;
return MAP_FAILED;
}
void* result = __mmap2(addr, size, prot, flags, fd, offset >> MMAP2_SHIFT);
size_t unsigned_offset = static_cast<size_t>(offset); // To avoid sign extension.
void* result = __mmap2(addr, size, prot, flags, fd, unsigned_offset >> MMAP2_SHIFT);
if (result != MAP_FAILED && (flags & (MAP_PRIVATE | MAP_ANONYMOUS)) != 0) {
ErrnoRestorer errno_restorer;