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: Fri, 29 Jul 2016 22:20:36 -0400 [thread overview]
Message-ID: <20160729222036.340b51ce@grimm.local.home> (raw)
In-Reply-To: <20160730005059.5krpl2xsvqfbnntj@treble>
On Fri, 29 Jul 2016 19:50:59 -0500
Josh Poimboeuf <jpoimboe@redhat.com> wrote:
> BTW, it would be really nice if ftrace_graph_ret_addr() were idempotent
> so we could get the "real" return address without having to pass in a
> state variable.
>
> For example we could add an "unsigned long *retp" pointer to
> ftrace_ret_stack, which points to the return address on the stack. Then
> we could get rid of the index state variable in ftrace_graph_ret_addr,
> and also then there would never be a chance of the stack dump getting
> out of sync with the ret_stack.
>
> What do you think?
>
I don't want to extend ret_stack as that is allocated 50 of these
structures for every task. That said, we have the "fp" field that's
used to check for frame pointer corruption when mcount is used. With
CC_USING_FENTRY, that field is ignored. Perhaps we could overload that
field for this.
-- Steve
next prev parent reply other threads:[~2016-07-30 2:20 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 [this message]
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
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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