From: Steven Rostedt <rostedt@goodmis.org>
To: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@kernel.org>, "H . Peter Anvin" <hpa@zytor.com>,
x86@kernel.org, linux-kernel@vger.kernel.org,
Andy Lutomirski <luto@amacapital.net>,
Linus Torvalds <torvalds@linux-foundation.org>,
Brian Gerst <brgerst@gmail.com>,
Kees Cook <keescook@chromium.org>,
Peter Zijlstra <peterz@infradead.org>,
Frederic Weisbecker <fweisbec@gmail.com>,
Byungchul Park <byungchul.park@lge.com>
Subject: Re: [PATCH 05/19] x86/dumpstack: fix function graph tracing stack dump reliability issues
Date: Tue, 2 Aug 2016 22:30:11 -0400 [thread overview]
Message-ID: <20160802223011.6209e28c@grimm.local.home> (raw)
In-Reply-To: <20160803015656.j6fxrgucmghh5gfn@treble>
On Tue, 2 Aug 2016 20:56:56 -0500
Josh Poimboeuf <jpoimboe@redhat.com> wrote:
> It's not specific to NMIs. The problem is that dump_trace() is starting
> from the frame pointed to by a pt_regs, rather than the current frame.
> Instead of starting with the current frame, the first 10 functions on
> the stack are skipped by the unwinder, but they're *not* skipped on the
> ret_stack. So it starts out out-of-sync.
OK, I see what you mean. If we do a dumpstack from interrupt passing in
the pt_regs of the kernel thread that was interrupted, even though
functions up to the interrupt was called and traced, which will show up
in the dump stack that shouldn't.
OK, you convinced me. Add the extra pointer, then we will have 4 longs
and 2 long longs in ftrace_ret_stack. That's not that bad.
-- Steve
next prev parent reply other threads:[~2016-08-03 2:33 UTC|newest]
Thread overview: 91+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-07-21 21:21 [PATCH 00/19] x86/dumpstack: rewrite x86 stack dump code Josh Poimboeuf
2016-07-21 21:21 ` [PATCH 01/19] x86/dumpstack: remove show_trace() Josh Poimboeuf
2016-07-21 21:49 ` Andy Lutomirski
2016-07-21 21:21 ` [PATCH 02/19] x86/dumpstack: add get_stack_pointer() and get_frame_pointer() Josh Poimboeuf
2016-07-21 21:53 ` Andy Lutomirski
2016-07-21 21:21 ` [PATCH 03/19] x86/dumpstack: remove unnecessary stack pointer arguments Josh Poimboeuf
2016-07-21 21:56 ` Andy Lutomirski
2016-07-22 1:41 ` Josh Poimboeuf
2016-07-22 2:29 ` Andy Lutomirski
2016-07-22 3:08 ` Brian Gerst
2016-07-21 21:21 ` [PATCH 04/19] x86/dumpstack: make printk_stack_address() more generally useful Josh Poimboeuf
2016-07-21 21:21 ` [PATCH 05/19] x86/dumpstack: fix function graph tracing stack dump reliability issues Josh Poimboeuf
2016-07-29 22:55 ` Steven Rostedt
2016-07-30 0:50 ` Josh Poimboeuf
2016-07-30 2:20 ` Steven Rostedt
2016-07-30 13:51 ` Josh Poimboeuf
2016-08-01 14:28 ` Steven Rostedt
2016-08-01 15:36 ` Josh Poimboeuf
2016-08-02 21:00 ` Josh Poimboeuf
2016-08-02 21:16 ` Steven Rostedt
2016-08-02 22:13 ` Josh Poimboeuf
2016-08-02 23:16 ` Steven Rostedt
2016-08-03 1:56 ` Josh Poimboeuf
2016-08-03 2:30 ` Steven Rostedt [this message]
2016-08-03 2:50 ` Josh Poimboeuf
2016-08-03 2:59 ` Steven Rostedt
2016-08-03 3:12 ` Josh Poimboeuf
2016-08-03 3:18 ` Steven Rostedt
2016-08-03 3:21 ` Steven Rostedt
2016-08-03 3:31 ` Josh Poimboeuf
2016-08-03 3:45 ` Steven Rostedt
2016-08-03 14:13 ` Josh Poimboeuf
2016-08-03 3:30 ` Josh Poimboeuf
2016-08-01 15:59 ` Josh Poimboeuf
2016-08-01 16:05 ` Steven Rostedt
2016-08-01 16:19 ` Josh Poimboeuf
2016-08-01 16:24 ` Josh Poimboeuf
2016-08-01 16:56 ` Steven Rostedt
2016-07-21 21:21 ` [PATCH 06/19] x86/dumpstack: remove extra brackets around "EOE" Josh Poimboeuf
2016-07-21 21:21 ` [PATCH 07/19] x86/dumpstack: add IRQ_USABLE_STACK_SIZE define Josh Poimboeuf
2016-07-21 22:01 ` Andy Lutomirski
2016-07-22 1:48 ` Josh Poimboeuf
2016-07-22 8:24 ` Ingo Molnar
2016-07-21 21:21 ` [PATCH 08/19] x86/dumpstack: don't disable preemption in show_stack_log_lvl() and dump_trace() Josh Poimboeuf
2016-07-21 21:21 ` [PATCH 09/19] x86/dumpstack: simplify in_exception_stack() Josh Poimboeuf
2016-07-21 22:05 ` Andy Lutomirski
2016-07-21 21:21 ` [PATCH 10/19] x86/dumpstack: add get_stack_info() interface Josh Poimboeuf
2016-07-22 23:26 ` Andy Lutomirski
2016-07-22 23:52 ` Andy Lutomirski
2016-07-23 13:09 ` Josh Poimboeuf
2016-07-22 23:54 ` Josh Poimboeuf
2016-07-23 0:15 ` Andy Lutomirski
2016-07-23 14:04 ` Josh Poimboeuf
2016-07-26 0:09 ` Andy Lutomirski
2016-07-26 16:26 ` Josh Poimboeuf
2016-07-26 17:51 ` Steven Rostedt
2016-07-26 18:56 ` Josh Poimboeuf
2016-07-26 20:59 ` Andy Lutomirski
2016-07-26 22:24 ` Josh Poimboeuf
2016-07-26 22:31 ` Steven Rostedt
2016-07-26 22:37 ` Andy Lutomirski
2016-07-26 16:47 ` Josh Poimboeuf
2016-07-26 17:49 ` Brian Gerst
2016-07-26 18:59 ` Josh Poimboeuf
2016-07-21 21:21 ` [PATCH 11/19] x86/dumptrace: add new unwind interface and implementations Josh Poimboeuf
2016-07-21 21:21 ` [PATCH 12/19] perf/x86: convert perf_callchain_kernel() to the new unwinder Josh Poimboeuf
2016-07-21 21:21 ` [PATCH 13/19] x86/stacktrace: convert save_stack_trace_*() " Josh Poimboeuf
2016-07-21 21:21 ` [PATCH 14/19] oprofile/x86: convert x86_backtrace() " Josh Poimboeuf
2016-07-21 21:21 ` [PATCH 15/19] x86/dumpstack: convert show_trace_log_lvl() " Josh Poimboeuf
2016-07-21 21:49 ` Byungchul Park
2016-07-22 1:38 ` Josh Poimboeuf
2016-07-21 21:21 ` [PATCH 16/19] x86/dumpstack: remove dump_trace() Josh Poimboeuf
2016-07-21 21:21 ` [PATCH 17/19] x86/entry/dumpstack: encode pt_regs pointer in frame pointer Josh Poimboeuf
2016-07-21 22:27 ` Andy Lutomirski
2016-07-21 21:21 ` [PATCH 18/19] x86/dumpstack: print stack identifier on its own line Josh Poimboeuf
2016-07-21 21:21 ` [PATCH 19/19] x86/dumpstack: print any pt_regs found on the stack Josh Poimboeuf
2016-07-21 22:32 ` Andy Lutomirski
2016-07-22 3:30 ` Josh Poimboeuf
2016-07-22 5:13 ` Andy Lutomirski
2016-07-22 15:57 ` Josh Poimboeuf
2016-07-22 21:46 ` Andy Lutomirski
2016-07-22 22:20 ` Josh Poimboeuf
2016-07-22 23:18 ` Andy Lutomirski
2016-07-22 23:30 ` Josh Poimboeuf
2016-07-22 23:39 ` Andy Lutomirski
2016-07-23 0:00 ` Josh Poimboeuf
2016-07-23 0:22 ` [PATCH 00/19] x86/dumpstack: rewrite x86 stack dump code Linus Torvalds
2016-07-23 0:31 ` Andy Lutomirski
2016-07-23 5:35 ` Josh Poimboeuf
2016-07-23 5:39 ` Linus Torvalds
2016-07-23 12:53 ` Josh Poimboeuf
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