diff options
| author | Vikram Mulukutla <markivx@codeaurora.org> | 2014-12-17 18:50:56 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-03-06 14:57:29 -0800 |
| commit | a0a645bf699f808e997fc7caa7cdeb459251bcdf (patch) | |
| tree | 56fb2f35346ce7329de7cd1d19bd71d32c3acf4d /kernel | |
| parent | 9cdaa7e29df63ad90f01b218b176425fd07de652 (diff) | |
tracing: Fix unmapping loop in tracing_mark_write
commit 7215853e985a4bef1a6c14e00e89dfec84f1e457 upstream.
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/1418871056-6614-1-git-send-email-markivx@codeaurora.org
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Reported-by: Lime Yang <limey@codeaurora.org>
Signed-off-by: Vikram Mulukutla <markivx@codeaurora.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel')
| -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 4a9079b9f082..361a827b4962 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -4942,7 +4942,7 @@ 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]); } |