diff options
Diffstat (limited to 'winsup/cygwin/mmap.cc')
| -rw-r--r-- | winsup/cygwin/mmap.cc | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/winsup/cygwin/mmap.cc b/winsup/cygwin/mmap.cc index 4218466..d4eddfc 100644 --- a/winsup/cygwin/mmap.cc +++ b/winsup/cygwin/mmap.cc @@ -917,6 +917,13 @@ mmap64 (void *addr, size_t len, int prot, int flags, int fd, off_t off) goto out; } + /* POSIX: When MAP_FIXED is not set, the implementation uses addr in an + implementation-defined manner to arrive at pa [the return address]. + Given that we refuse addr if it's not exactly at a page boundary, we + can just make sure addr does so indiscriminately. Just round down + to the next lower page boundary. */ + addr = (void *) rounddown ((uintptr_t) addr, pagesize); + if (!anonymous (flags) && fd != -1) { /* Ensure that fd is open */ |