Messages in this thread | | | From | Andrew Lutomirski <> | Date | Sat, 28 May 2011 00:14:25 -0400 | Subject | Re: [GIT PULL] x86: Put back -pg to tsc.o and add no GCOV to vread_tsc_64.o |
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On Fri, May 27, 2011 at 11:53 PM, Steven Rostedt <rostedt@goodmis.org> wrote: > > Ingo, > > While running ktest randconfig tests on latest Linus's tree, I hit a > case where the function graph tracer caused a nasty crash, or even a > reboot. Using the ktest git bisect utility, I quickly found that the > crash was due to the commit: > > 44259b1a x86-64: Move vread_tsc into a new file with sensible options > > I found that it removed the -pg from tsc.o causing accesses to tsc to be > traced. The function graph tracer uses the tsc outside its recursive > protection and this caused the crash.
Oops, I didn't think of that.
> > But this was not the only bug. As I had 3 different configs that crashed > in my randconfig tests, I tested all three. The first two ran fine with > the update of the tsc.o with the -pg option, but the third config failed > with the init process taking a segfault in the vread_tsc function. > > That same patch added the vread_tsc_64.o but did not disable GCOV from > it. Thomas noticed that GCOV was set in that config and after disabling > GCOV, the strange accesses to kernel space in that function went away.
And that was just an oversight on my part. Sorry.
> Steven Rostedt (1): > x86: Put back -pg to tsc.o and add no GCOV to vread_tsc_64.o
Looks fine to me.
--Andy -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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