Messages in this thread | | | Date | Tue, 4 Apr 2023 18:24:28 -0400 | From | Steven Rostedt <> | Subject | Re: [BUG RESEND] [BISECTED]: selftest: ftracetest: memleak in vfs_write() |
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On Tue, 4 Apr 2023 15:07:44 -0700 Eric Biggers <ebiggers@kernel.org> wrote:
> This looks like an issue with the tracing subsystem. I appreciate that you've > now added the tracing maintainers to Cc. I don't think your bisection to commit > 71946a25f357 ("Merge tag 'mmc-v6.2' ...") is correct; that looks unrelated.
No that is not the correct commit. I think I see the issue. The error log of a tracing instance doesn't seem to be freed if the instance is removed.
I'm guessing this can cause the bug:
# cd /sys/kernel/tracincg # mkdir instances/foo # echo 'p:nothing no_function_here' > instances/foo/dynamic_events # rmdir instances/foo
I haven't tried the above commands so there may be a syntax error, but I bet that would cause the issue. Basically, you need to create an instance, cause a syntax error in creating something (which will add to the error log list that shows the error), and then delete the instance.
I don't see where it would clean up the error log in that case, and it would get leaked.
I'll write up a patch to fix this today (after confirming that does indeed cause a leak).
-- Steve
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