pa-fazil
/
android_bionic
mirror of https://github.com/fazilsheik96/android_bionic.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Avoid sign extension of the mmap offset. 

off_t is signed to support seeking backwards, but that's a liability
when using off_t to represent a subset of a file.

Change-Id: I2a3615166eb16212347eb47f1242e3bfb93c2022
This commit is contained in:
Elliott Hughes 2013-07-25 10:15:07 -07:00
parent bfba6aac99
commit e320a8c780
1 changed files with 3 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
libc/bionic/mmap.cpp
View File

@ -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;