diff options
| author | Vikram Mulukutla <[email protected]> | 2014-12-17 18:50:56 -0800 |
|---|---|---|
| committer | Steven Rostedt <[email protected]> | 2015-02-09 18:47:09 -0500 |
| commit | 7215853e985a4bef1a6c14e00e89dfec84f1e457 (patch) | |
| tree | 6e3804798e9adeaf67bac5e94b230288999a9cc7 | |
| parent | 7496946a88ab48830f3101c08f8e770cc0902bbb (diff) | |
tracing: Fix unmapping loop in tracing_mark_write
Commit 6edb2a8a385f0cdef51dae37ff23e74d76d8a6ce introduced
an array map_pages that contains the addresses returned by
kmap_atomic. However, when unmapping those pages, map_pages[0]
is unmapped before map_pages[1], breaking the nesting requirement
as specified in the documentation for kmap_atomic/kunmap_atomic.
This was caught by the highmem debug code present in kunmap_atomic.
Fix the loop to do the unmapping properly.
Link: http://lkml.kernel.org/r/[email protected]
Cc: [email protected] # 3.5+
Reviewed-by: Stephen Boyd <[email protected]>
Reported-by: Lime Yang <[email protected]>
Signed-off-by: Vikram Mulukutla <[email protected]>
Signed-off-by: Steven Rostedt <[email protected]>
| -rw-r--r-- | kernel/trace/trace.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 5afce60e1b68..2078b86750e0 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -4928,7 +4928,7 @@ tracing_mark_write(struct file *filp, const char __user *ubuf, *fpos += written; out_unlock: - for (i = 0; i < nr_pages; i++){ + for (i = nr_pages - 1; i >= 0; i--) { kunmap_atomic(map_page[i]); put_page(pages[i]); } |