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| author | Vikram Mulukutla <markivx@codeaurora.org> | 2014-12-17 18:50:56 -0800 |
|---|---|---|
| committer | Luis Henriques <luis.henriques@canonical.com> | 2015-03-02 13:17:11 +0000 |
| commit | 366475b9c8ab44a17695c051c21c01bc47a9d925 (patch) | |
| tree | b820a0e78a17094a4c4c611cbc7b597f4743f827 /kernel/trace | |
| parent | 3b3c7a2a4fc27e14c6fbc2e3d37ff4e62b01d889 (diff) | |
| download | linux-stable-366475b9c8ab44a17695c051c21c01bc47a9d925.tar.gz linux-stable-366475b9c8ab44a17695c051c21c01bc47a9d925.tar.bz2 linux-stable-366475b9c8ab44a17695c051c21c01bc47a9d925.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: Luis Henriques <luis.henriques@canonical.com>
Diffstat (limited to 'kernel/trace')
| -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 01603e48742e..8b924fb7f915 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -4894,7 +4894,7 @@ 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]); } |