From: Josh Poimboeuf <jpoimboe@redhat.com>
To: Jann Horn <jannh@google.com>
Cc: the arch/x86 maintainers <x86@kernel.org>,
kernel list <linux-kernel@vger.kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Vince Weaver <vincent.weaver@maine.edu>, Dave Jones <dsj@fb.com>,
Miroslav Benes <mbenes@suse.cz>,
Andy Lutomirski <luto@kernel.org>,
Steven Rostedt <rostedt@goodmis.org>,
Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [PATCH 13/14] x86/unwind/orc: Add more unwinder warnings
Date: Thu, 12 Mar 2020 14:20:05 -0500 [thread overview]
Message-ID: <20200312192005.cv56gzdwwjzttzzy@treble> (raw)
In-Reply-To: <CAG48ez2L5eBfU57_bFnSPSN7DUrocJB56wBLR6cE0e_5DdkURg@mail.gmail.com>
On Thu, Mar 12, 2020 at 08:12:16PM +0100, Jann Horn wrote:
> On Thu, Mar 12, 2020 at 6:31 PM Josh Poimboeuf <jpoimboe@redhat.com> wrote:
> > Make sure warnings are displayed for all error scenarios (except when
> > encountering an empty unwind hint).
> [...]
> > /* End-of-stack check for kernel threads: */
> > if (orc->sp_reg == ORC_REG_UNDEFINED) {
> > - if (!orc->end)
> > + if (!orc->end) {
> > + /*
> > + * This is reported as an error for the caller, but
> > + * otherwise it isn't worth warning about. In theory
> > + * it can only happen when hitting UNWIND_HINT_EMPTY in
> > + * entry code, close to a kernel exit point.
> > + */
> > goto err;
>
> But UNWIND_HINT_EMPTY sets end=1, right? And this is the branch for
> end==0. What am I missing?
You're right. I need to revisit that comment...
--
Josh
next prev parent reply other threads:[~2020-03-12 19:20 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-12 17:30 [PATCH 00/14] x86/unwind/orc: ORC fixes Josh Poimboeuf
2020-03-12 17:30 ` [PATCH 01/14] x86/dumpstack: Add SHOW_REGS_IRET mode Josh Poimboeuf
2020-03-13 11:10 ` Miroslav Benes
2020-03-12 17:30 ` [PATCH 02/14] objtool: Fix stack offset tracking for indirect CFAs Josh Poimboeuf
2020-03-12 17:30 ` [PATCH 03/14] x86/entry/64: Fix unwind hints in register clearing code Josh Poimboeuf
2020-03-12 19:29 ` Andy Lutomirski
2020-03-12 19:57 ` Josh Poimboeuf
2020-03-12 20:07 ` Peter Zijlstra
2020-03-12 21:24 ` Jann Horn
2020-03-12 17:30 ` [PATCH 04/14] x86/entry/64: Fix unwind hints in kernel exit path Josh Poimboeuf
2020-03-12 17:30 ` [PATCH 05/14] x86/entry/64: Fix unwind hints in __switch_to_asm() Josh Poimboeuf
2020-03-12 17:30 ` [PATCH 06/14] x86/entry/64: Fix unwind hints in rewind_stack_do_exit() Josh Poimboeuf
2020-03-12 17:30 ` [PATCH 07/14] x86/unwind/orc: Convert global variables to static Josh Poimboeuf
2020-03-12 17:30 ` [PATCH 08/14] x86/unwind: Prevent false warnings for non-current tasks Josh Poimboeuf
2020-03-12 17:30 ` [PATCH 09/14] x86/unwind/orc: Don't skip the first frame for inactive tasks Josh Poimboeuf
2020-03-12 17:30 ` [PATCH 10/14] x86/unwind/orc: Prevent unwinding before ORC initialization Josh Poimboeuf
2020-03-13 12:24 ` Miroslav Benes
2020-03-12 17:30 ` [PATCH 11/14] x86/unwind/orc: Fix error path for bad ORC entry type Josh Poimboeuf
2020-03-12 17:30 ` [PATCH 12/14] x86/unwind/orc: Fix premature unwind stoppage due to IRET frames Josh Poimboeuf
2020-03-12 17:30 ` [PATCH 13/14] x86/unwind/orc: Add more unwinder warnings Josh Poimboeuf
2020-03-12 19:12 ` Jann Horn
2020-03-12 19:20 ` Josh Poimboeuf [this message]
2020-03-12 17:30 ` [PATCH 14/14] x86/unwind/orc: Add 'unwind_debug' cmdline option Josh Poimboeuf
2020-03-12 19:15 ` [PATCH 00/14] x86/unwind/orc: ORC fixes Peter Zijlstra
2020-03-13 14:00 ` Miroslav Benes
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