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| author | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2020-11-05 21:32:42 -0500 |
|---|---|---|
| committer | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2020-11-06 08:41:47 -0500 |
| commit | 4b750b573c5b3ee10e33c1573eaa94a9dad62f19 (patch) | |
| tree | b889901b1bb61cacd0d4503881412ebfc834bae8 /kernel/livepatch | |
| parent | 13f3ea9a2c829f28610bb8772a8b9c328412930e (diff) | |
| download | linux-4b750b573c5b3ee10e33c1573eaa94a9dad62f19.tar.bz2 | |
livepatch: Trigger WARNING if livepatch function fails due to recursion
If for some reason a function is called that triggers the recursion
detection of live patching, trigger a warning. By not executing the live
patch code, it is possible that the old unpatched function will be called
placing the system into an unknown state.
Link: https://lore.kernel.org/r/20201029145709.GD16774@alley
Link: https://lkml.kernel.org/r/20201106023547.312639435@goodmis.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Joe Lawrence <joe.lawrence@redhat.com>
Cc: live-patching@vger.kernel.org
Suggested-by: Miroslav Benes <mbenes@suse.cz>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Acked-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'kernel/livepatch')
| -rw-r--r-- | kernel/livepatch/patch.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/livepatch/patch.c b/kernel/livepatch/patch.c index 6c0164d24bbd..15480bf3ce88 100644 --- a/kernel/livepatch/patch.c +++ b/kernel/livepatch/patch.c @@ -50,7 +50,7 @@ static void notrace klp_ftrace_handler(unsigned long ip, ops = container_of(fops, struct klp_ops, fops); bit = ftrace_test_recursion_trylock(); - if (bit < 0) + if (WARN_ON_ONCE(bit < 0)) return; /* * A variant of synchronize_rcu() is used to allow patching functions |