diff options
| author |   Artem Savkov <asavkov@redhat.com> | 2020-03-06 18:43:17 +0100 |
|---|---|---|
| committer |   Steven Rostedt (VMware) <rostedt@goodmis.org> | 2020-03-11 10:37:12 -0400 |
| commit | d9815bff6b379ff46981bea9dfeb146081eab314 (patch) | |
| tree | 9b5f536c2679ea760ac97c053da6abf86b918439 /kernel/trace | |
| parent | bootconfig: Fix CONFIG_BOOTTIME_TRACING dependency issue (diff) | |
| download | linux-dev-d9815bff6b379ff46981bea9dfeb146081eab314.tar.xz linux-dev-d9815bff6b379ff46981bea9dfeb146081eab314.zip | |
ftrace: Return the first found result in lookup_rec()
It appears that ip ranges can overlap so. In that case lookup_rec()
returns whatever results it got last even if it found nothing in last
searched page.
This breaks an obscure livepatch late module patching usecase:
- load livepatch
- load the patched module
- unload livepatch
- try to load livepatch again
To fix this return from lookup_rec() as soon as it found the record
containing searched-for ip. This used to be this way prior lookup_rec()
introduction.
Link: http://lkml.kernel.org/r/20200306174317.21699-1-asavkov@redhat.com
Cc: stable@vger.kernel.org
Fixes: 7e16f581a817 ("ftrace: Separate out functionality from ftrace_location_range()")
Signed-off-by: Artem Savkov <asavkov@redhat.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace')
| -rw-r--r-- | kernel/trace/ftrace.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 3f7ee102868a..fd81c7de77a7 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -1547,6 +1547,8 @@ static struct dyn_ftrace *lookup_rec(unsigned long start, unsigned long end) rec = bsearch(&key, pg->records, pg->index, sizeof(struct dyn_ftrace), ftrace_cmp_recs); + if (rec) + break; } return rec; } |