From: "me at serhei dot io" <sourceware-bugzilla@sourceware.org>
To: systemtap@sourceware.org
Subject: [Bug bpf/26109] New: bug when begin probe exits quickly
Date: Wed, 10 Jun 2020 23:32:05 +0000 [thread overview]
Message-ID: <bug-26109-6586@http.sourceware.org/bugzilla/> (raw)
https://sourceware.org/bugzilla/show_bug.cgi?id=26109
Bug ID: 26109
Summary: bug when begin probe exits quickly
Product: systemtap
Version: unspecified
Status: NEW
Severity: normal
Priority: P2
Component: bpf
Assignee: systemtap at sourceware dot org
Reporter: me at serhei dot io
Target Milestone: ---
if a bpf begin probe sets exit status, the main thread will skip the pause()
call and immediately deallocate global data structures. Then the
perf_event_loop thread will run on the corrupted data and occasionally fail.
Example result is an assertion failure due count_active_cpus() running on
corrupted data.
Could change the main thread to join() instead of detach(), but then all
threads must be modified to listen for exit status including exit status from
begin thread.
I think if the begin probe was running, it wasn't correct to start the
perf_event_loop (or PERF_EVENT_IOC_ENABLE, or any of the procfs threads) in the
first place, as those things logically happen after the begin probe has already
exited. Simply clean up and exit.
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next reply other threads:[~2020-06-10 23:32 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-10 23:32 me at serhei dot io [this message]
2020-06-11 0:41 ` [Bug bpf/26109] " me at serhei dot io
2020-06-11 0:41 ` me at serhei dot io
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