| From 569d1423ac2b585b5cb38bee545b5e0ae2bd7f67 Mon Sep 17 00:00:00 2001 |
| From: James Hogan <james.hogan@imgtec.com> |
| Date: Thu, 17 May 2012 12:42:54 +0100 |
| Subject: [PATCH] mmap()->sys_mmap2: do unsigned shift of offset |
| |
| Fix the implementation of mmap based on the mmap2 system call, to |
| construct pgoffset from offset with an unsigned shift rather than a |
| signed (off_t) shift. The mmap2 test in the testsuite catches this case |
| by mmap'ing with a large offset (with the sign bit set). The signed |
| shift repeats the sign bit making the page shift way out of range. This |
| is already fixed similarly in mmap64(). |
| |
| Signed-off-by: James Hogan <james.hogan@imgtec.com> |
| Signed-off-by: Mike Frysinger <vapier@gentoo.org> |
| --- |
| libc/sysdeps/linux/common/mmap.c | 3 ++- |
| 1 file changed, 2 insertions(+), 1 deletion(-) |
| |
| diff --git a/libc/sysdeps/linux/common/mmap.c b/libc/sysdeps/linux/common/mmap.c |
| index 8995898..d53eabb 100644 |
| --- a/libc/sysdeps/linux/common/mmap.c |
| +++ b/libc/sysdeps/linux/common/mmap.c |
| @@ -63,7 +63,8 @@ __ptr_t mmap(__ptr_t addr, size_t len, int prot, int flags, int fd, __off_t offs |
| __set_errno(EINVAL); |
| return MAP_FAILED; |
| } |
| - return __syscall_mmap2(addr, len, prot, flags, fd, offset >> MMAP2_PAGE_SHIFT); |
| + return __syscall_mmap2(addr, len, prot, flags, |
| + fd, ((__u_long) offset >> MMAP2_PAGE_SHIFT)); |
| } |
| |
| libc_hidden_def(mmap) |
| -- |
| 1.7.10.4 |
| |
