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| author | Vasily Averin <vvs@virtuozzo.com> | 2020-01-24 10:03:01 +0300 |
|---|---|---|
| committer | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2020-01-30 09:46:27 -0500 |
| commit | 039958a5f7aad695d4d52683c7d48aa13fb18249 (patch) | |
| tree | 2abfc0f938e70c7b7a9a8d7e59babb44092c33ef /kernel | |
| parent | e4075e8bdffd93a9b6d6e1d52fabedceeca5a91b (diff) | |
| download | linux-039958a5f7aad695d4d52683c7d48aa13fb18249.tar.gz | |
tracing: eval_map_next() should always increase position index
if seq_file .next fuction does not change position index, read after some lseek can generate unexpected output. Link: http://lkml.kernel.org/r/7ad85b22-1866-977c-db17-88ac438bc764@virtuozzo.com Signed-off-by: Vasily Averin <vvs@virtuozzo.com> [ This is not a bug fix, it just makes it "technically correct" which is why I applied it. NULL is only returned on an anomaly which triggers a WARN_ON ] Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/trace/trace.c | 4 |
1 files changed, 1 insertions, 3 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 6a28b1b9bf42..8d144fd94aa8 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -5399,14 +5399,12 @@ static void *eval_map_next(struct seq_file *m, void *v, loff_t *pos) * Paranoid! If ptr points to end, we don't want to increment past it. * This really should never happen. */ + (*pos)++; ptr = update_eval_map(ptr); if (WARN_ON_ONCE(!ptr)) return NULL; ptr++; - - (*pos)++; - ptr = update_eval_map(ptr); return ptr; |