aboutsummaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorVikram Mulukutla <markivx@codeaurora.org>2014-12-17 18:50:56 -0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-03-06 14:43:28 -0800
commitf77fc6971c4fb1a656cb19d913a1eb2c393dfc92 (patch)
treee991835234f5f0f4135806265c61aa59fbc63bc5
parent9a3a249a942ded8bb8a7faedeeee310186139f8a (diff)
downloadlinux-yocto-f77fc6971c4fb1a656cb19d913a1eb2c393dfc92.tar.gz
linux-yocto-f77fc6971c4fb1a656cb19d913a1eb2c393dfc92.tar.bz2
linux-yocto-f77fc6971c4fb1a656cb19d913a1eb2c393dfc92.zip
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>
-rw-r--r--kernel/trace/trace.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 71136720ffa1..813b021379f5 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -4694,7 +4694,7 @@ 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]);
}