Red Hat Bugzilla – Bug 498040
intermittent crashes on prototype kprobe.function("foo") probes for erroneous "foo"
Last modified: 2009-09-02 06:01:21 EDT
A bug in the new code for debuginfo-less probing in 0.9.7 may result in
occasional kernel BUG/crashes, when the function parameter causes
a failed registration. I believe Josh has a reproducing recipe (please
attach here), and also has two or three patches on mainline systemtap
that could be backported to rhel5.4's new build.
I have a reproducer that works on Fedora, but when I tried it on RHEL5.4, I discovered that the debuginfo-less probing is completely broken. It doesn't get past the compile phase with a simple probe, so we never even get to the potential BUG point in the kernel.
I will put together a patch which fixes the compile problems and also fixes the runtime BUG.
Created attachment 341665 [details]
Backport fixes for dwarfless kprobes
This is a backport of a few fixes for dwarfless kprobes that were
made after the 0.9.7 release. The upstream commits are:
5badd4d... Don't terminate when a dwarfless kprobe fails
46856d8... Fill out the pp() for dwarfless kprobes
8874701... fix kprobe.* probes so they don't break -p4 if script
also has kernel.* probes
9f38e65... Handle kprobe struct field symbol_name as either char *
or const char *.
An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on therefore solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.