Fix segfault due to bad munmap()

Bruce reports:

The latest code from git (built using clang) causes a segfault after printing the usage text when "./fio" is run:

[New LWP 100111]
No jobs(s) defined

fio-2.2.5-28-g93eeb
[usage text]
[New Thread 801c06400 (LWP 100111/fio)]

Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 801c06400 (LWP 100111/fio)]
flist_empty (head=0x802000040) at flist.h:119
119             return head->next == head;
Current language:  auto; currently minimal
(gdb) p head
$1 = (const struct flist_head *) 0x802000040

which is due to a bug in the filelock code, that uses
fio_mutex_remove() to remove the mutex. But that mutex is embedded
inside another mmap'ed region, hence we then segfault on later
deferencing pointers.

Signed-off-by: Jens Axboe <axboe@fb.com>

diff --git a/filelock.c b/filelock.c
index 17b5a85aa4559e1a20c864a1106e18f4baf58c9c..b1130071ea982ad38e7277ec6c0b7886f4c84bf2 100644 (file)
--- a/filelock.c
+++ b/filelock.c
@@ -101,7 +101,7 @@ void fio_filelock_exit(void)
                return;
 
        assert(flist_empty(&fld->list));
-       fio_mutex_remove(&fld->lock);
+       __fio_mutex_remove(&fld->lock);
 
        while (!flist_empty(&fld->free_list)) {
                struct fio_filelock *ff;
@@ -109,7 +109,7 @@ void fio_filelock_exit(void)
                ff = flist_first_entry(&fld->free_list, struct fio_filelock, list);
 
                flist_del_init(&ff->list);
-               fio_mutex_remove(&ff->lock);
+               __fio_mutex_remove(&ff->lock);
        }
 
        sfree(fld);