Hi Steven, On Wed, Dec 10, 2014 at 11:09:13PM -0500, Steven Rostedt wrote: > On Wed, 10 Dec 2014 15:17:32 -0800 > Fengguang Wu <[email protected]> wrote: > > > Hi Steven, > > > > 0day kernel testing robot got the below dmesg and the first bad commit is > > > > git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master > > commit 6a06bdbf7f9c669743f58084991ba280f2925586 > > Author: Steven Rostedt (Red Hat) <[email protected]> > > AuthorDate: Mon Nov 24 21:00:34 2014 -0500 > > Commit: Steven Rostedt <[email protected]> > > CommitDate: Mon Dec 1 14:08:58 2014 -0500 > > > > ftrace/fgraph/x86: Have prepare_ftrace_return() take ip as first > > parameter > > > > The function graph helper function prepare_ftrace_return() which does > > the work > > to hijack the parent pointer has that parent pointer as its first > > parameter. > > Instead, if we make it the second parameter and have ip as the first > > parameter > > (self_addr), then it can use the %rdi from save_mcount_regs that loads > > it > > already. > > > > Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1411262304010.3961@nanos > > > > Reviewed-by: Thomas Gleixner <[email protected]> > > Signed-off-by: Steven Rostedt <[email protected]> > > Crap! Yeah, I was wondering how this could be the bug, but then I > realized this was i386 not x86_64 and I never updated the i386 call to > prepare_ftrace_return(). > > Does this patch fix it?
Yes, it fixed the issue. Tested-by: Fengguang Wu <[email protected]> Thanks, Fengguang > > diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S > index b553ed89e5f5..df3e608d409b 100644 > --- a/arch/x86/kernel/entry_32.S > +++ b/arch/x86/kernel/entry_32.S > @@ -1192,10 +1192,10 @@ ENTRY(ftrace_graph_caller) > pushl %eax > pushl %ecx > pushl %edx > - movl 0xc(%esp), %edx > - lea 0x4(%ebp), %eax > + movl 0xc(%esp), %eax > + lea 0x4(%ebp), %edx > movl (%ebp), %ecx > - subl $MCOUNT_INSN_SIZE, %edx > + subl $MCOUNT_INSN_SIZE, %eax > call prepare_ftrace_return > popl %edx > popl %ecx -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
