From: Steven Rostedt <rostedt@goodmis.org>
To: "H. Peter Anvin" <hpa@zytor.com>
Cc: Vince Weaver <vincent.weaver@maine.edu>,
Peter Zijlstra <peterz@infradead.org>,
Linux Kernel <linux-kernel@vger.kernel.org>,
Ingo Molnar <mingo@redhat.com>, "H.J. Lu" <hjl.tools@gmail.com>
Subject: Re: perf_fuzzer compiled for x32 causes reboot
Date: Mon, 24 Feb 2014 14:13:29 -0500 [thread overview]
Message-ID: <20140224141329.1cd3bb52@gandalf.local.home> (raw)
In-Reply-To: <530B90A5.3090302@zytor.com>
On Mon, 24 Feb 2014 10:34:13 -0800
"H. Peter Anvin" <hpa@zytor.com> wrote:
> On 02/24/2014 10:07 AM, Vince Weaver wrote:
> >>
> >> Anyway I've attached the full tail end of the trace if you want to see
> >> everything that happens.
> >
> > and then I note there are *two* kernel page faults.
> >
> > perf_fuzzer-2979 [000] 161.475924: page_fault_kernel: address=irq_stack_union ip=copy_user_generic_string error_code=0x0
> > address=0x1 ip=0xffffffff812a7d9c error_code=0x0
> > perf_fuzzer-2979 [000] 161.475924: function: __do_page_fault
> > perf_fuzzer-2979 [000] 161.475924: function: bad_area_nosemaphore
> > perf_fuzzer-2979 [000] 161.475925: function: __bad_area_nosemaphore
> > perf_fuzzer-2979 [000] 161.475925: function: no_context
> > perf_fuzzer-2979 [000] 161.475925: function: fixup_exception
> > perf_fuzzer-2979 [000] 161.475926: function: search_exception_tables
> > perf_fuzzer-2979 [000] 161.475926: function: search_extable
> > perf_fuzzer-2979 [000] 161.475927: function: copy_user_handle_tail
> > perf_fuzzer-2979 [000] 161.475927: function: trace_do_page_fault
> > perf_fuzzer-2979 [000] 161.475928: page_fault_kernel: address=irq_stack_union ip=copy_user_handle_tail error_code=0x0
> > address=0x1 ip=0xffffffff812a92bb error_code=0x0
> > perf_fuzzer-2979 [000] 161.475928: function: __do_page_fault
> > perf_fuzzer-2979 [000] 161.475928: function: bad_area_nosemaphore
> > perf_fuzzer-2979 [000] 161.475929: function: __bad_area_nosemaphore
> > perf_fuzzer-2979 [000] 161.475929: function: no_context
> > perf_fuzzer-2979 [000] 161.475929: function: fixup_exception
> > perf_fuzzer-2979 [000] 161.475929: function: search_exception_tables
> > perf_fuzzer-2979 [000] 161.475930: function: search_extable
> > perf_fuzzer-2979 [000] 161.475931: function: perf_output_begin
> > perf_fuzzer-2979 [000] 161.475931: function: perf_output_copy
> >
> > That second one is in copy_user_handle_tail()
> >
>
> Either way, it really seems like we have a case of CR2 leakage out of
> the NMI context.
Ah, and x86_64 saves off the cr2 register when entering NMI and restores
it before returning. But it seems to be missing from the i386 code.
-- Steve
next prev parent reply other threads:[~2014-02-24 19:13 UTC|newest]
Thread overview: 115+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-02-21 20:25 perf_fuzzer causes reboot Vince Weaver
2014-02-21 22:13 ` perf_fuzzer compiled for x32 " Vince Weaver
2014-02-21 22:34 ` Vince Weaver
2014-02-22 4:50 ` Vince Weaver
2014-02-22 5:03 ` H. Peter Anvin
2014-02-22 6:26 ` H. Peter Anvin
2014-02-23 5:18 ` Vince Weaver
2014-02-23 5:24 ` H. Peter Anvin
2014-02-23 6:07 ` H. Peter Anvin
2014-02-23 14:05 ` Vince Weaver
2014-02-24 3:02 ` Vince Weaver
2014-02-24 5:22 ` H. Peter Anvin
2014-02-24 15:35 ` Vince Weaver
2014-02-24 16:34 ` Vince Weaver
2014-02-24 16:47 ` H. Peter Anvin
2014-02-24 17:10 ` Vince Weaver
2014-02-24 17:25 ` Peter Zijlstra
2014-02-24 17:32 ` Vince Weaver
2014-02-24 17:40 ` H. Peter Anvin
2014-02-24 18:00 ` Vince Weaver
2014-02-24 18:07 ` Vince Weaver
2014-02-24 18:34 ` H. Peter Anvin
2014-02-24 19:13 ` Steven Rostedt [this message]
2014-02-24 19:15 ` H. Peter Anvin
2014-02-24 19:30 ` Peter Zijlstra
2014-02-24 19:32 ` Steven Rostedt
2014-02-25 3:49 ` H. Peter Anvin
2014-02-25 14:07 ` Vince Weaver
2014-02-25 14:34 ` H. Peter Anvin
2014-02-25 14:43 ` Steven Rostedt
2014-02-25 15:33 ` Vince Weaver
2014-02-26 15:06 ` Vince Weaver
2014-02-27 22:06 ` Vince Weaver
2014-02-27 22:31 ` Steven Rostedt
2014-02-27 22:52 ` H. Peter Anvin
2014-02-27 23:30 ` Steven Rostedt
2014-02-27 23:46 ` H. Peter Anvin
2014-02-28 1:00 ` Vince Weaver
2014-02-28 20:34 ` Paul E. McKenney
2014-02-28 20:47 ` Steven Rostedt
2014-02-28 20:54 ` Peter Zijlstra
2014-02-28 21:17 ` Paul E. McKenney
2014-02-28 21:27 ` Peter Zijlstra
2014-02-28 21:51 ` Paul E. McKenney
2014-02-28 21:55 ` Peter Zijlstra
2014-02-28 22:05 ` Steven Rostedt
2014-02-28 22:23 ` Paul E. McKenney
2014-02-28 1:34 ` Vince Weaver
2014-02-28 2:17 ` H. Peter Anvin
2014-02-28 2:57 ` Steven Rostedt
2014-02-28 11:11 ` Peter Zijlstra
2014-02-28 13:37 ` Steven Rostedt
2014-02-28 14:15 ` Vince Weaver
2014-02-28 14:23 ` Steven Rostedt
2014-02-28 15:07 ` Vince Weaver
2014-02-28 15:13 ` H. Peter Anvin
2014-02-28 15:40 ` Peter Zijlstra
2014-02-28 16:15 ` H. Peter Anvin
2014-02-28 16:29 ` Steven Rostedt
2014-02-28 19:33 ` [PATCH] x86: Rename copy_from_user_nmi() to copy_from_user_trace() Steven Rostedt
2014-02-28 20:46 ` Peter Zijlstra
2014-02-28 20:51 ` Steven Rostedt
2014-02-28 20:58 ` Peter Zijlstra
2014-02-28 21:01 ` Steven Rostedt
2014-02-28 21:17 ` Peter Zijlstra
2014-02-28 20:56 ` perf_fuzzer compiled for x32 causes reboot Peter Zijlstra
2014-02-28 21:06 ` Steven Rostedt
2014-03-01 9:16 ` Ingo Molnar
2014-03-01 9:50 ` Borislav Petkov
2014-03-01 16:50 ` H. Peter Anvin
2014-03-04 23:05 ` Borislav Petkov
2014-03-03 9:16 ` Peter Zijlstra
2014-02-28 20:55 ` Peter Zijlstra
2014-02-28 15:20 ` Steven Rostedt
2014-02-28 15:30 ` Steven Rostedt
2014-02-28 20:38 ` H. Peter Anvin
2014-02-28 20:46 ` Steven Rostedt
2014-02-28 21:18 ` Vince Weaver
2014-02-28 21:30 ` Steven Rostedt
2014-02-28 23:34 ` Vince Weaver
2014-03-01 0:43 ` H. Peter Anvin
2014-03-01 3:36 ` Steven Rostedt
2014-03-01 16:24 ` Andi Kleen
2014-03-02 15:34 ` Vince Weaver
2014-03-02 16:02 ` Vince Weaver
2014-02-28 9:39 ` Peter Zijlstra
2014-02-24 17:40 ` Peter Zijlstra
2014-02-24 17:41 ` Vince Weaver
2014-02-24 17:42 ` H. Peter Anvin
2014-02-24 17:52 ` H. Peter Anvin
2014-02-28 15:33 [PATCH] x86 trace: Fix page fault tracing bug Jiri Olsa
2014-02-28 15:47 ` Peter Zijlstra
2014-02-28 16:05 ` [PATCHv2] " Jiri Olsa
2014-02-28 16:11 ` H. Peter Anvin
2014-02-28 16:23 ` Steven Rostedt
2014-02-28 16:15 ` Steven Rostedt
2014-03-05 0:03 ` [tip:x86/urgent] x86, trace: Fix CR2 corruption when tracing page faults tip-bot for Jiri Olsa
2014-03-05 11:14 ` Peter Zijlstra
2014-03-05 12:20 ` Steven Rostedt
2014-03-05 12:25 ` Peter Zijlstra
2014-03-05 12:33 ` Steven Rostedt
2014-03-05 12:54 ` Peter Zijlstra
2014-03-05 13:02 ` Peter Zijlstra
2014-03-05 13:07 ` Peter Zijlstra
2014-03-05 12:36 ` Peter Zijlstra
2014-03-05 13:00 ` Steven Rostedt
2014-03-05 13:08 ` Peter Zijlstra
2014-03-05 21:37 ` H. Peter Anvin
2014-03-06 8:40 ` Peter Zijlstra
2014-03-06 11:02 ` Steven Rostedt
2014-03-06 14:53 ` [PATCH] x86: Further robustify CR2 handling vs tracing Peter Zijlstra
2014-03-07 23:07 ` [tip:x86/urgent] x86, trace: " tip-bot for Peter Zijlstra
2014-02-28 15:47 ` [PATCH] x86 trace: Fix page fault tracing bug Jiri Olsa
2014-02-28 16:00 ` Steven Rostedt
2014-02-28 16:01 ` Steven Rostedt
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