From: Steven Rostedt <rostedt@goodmis.org>
To: Jens Remus <jremus@linux.ibm.com>
Cc: Steven Rostedt <rostedt@kernel.org>,
linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org,
bpf@vger.kernel.org, x86@kernel.org,
Masami Hiramatsu <mhiramat@kernel.org>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
Josh Poimboeuf <jpoimboe@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@kernel.org>, Jiri Olsa <jolsa@kernel.org>,
Namhyung Kim <namhyung@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Andrii Nakryiko <andrii@kernel.org>,
Indu Bhagat <indu.bhagat@oracle.com>,
"Jose E. Marchesi" <jemarch@gnu.org>,
Beau Belgrave <beaub@linux.microsoft.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Andrew Morton <akpm@linux-foundation.org>,
Jens Axboe <axboe@kernel.dk>, Florian Weimer <fweimer@redhat.com>,
Sam James <sam@gentoo.org>, Heiko Carstens <hca@linux.ibm.com>,
Vasily Gorbik <gor@linux.ibm.com>
Subject: Re: [PATCH v13 02/14] unwind_user: Add frame pointer support
Date: Thu, 10 Jul 2025 13:08:59 -0400 [thread overview]
Message-ID: <20250710130859.41f3d5d0@batman.local.home> (raw)
In-Reply-To: <155f22cb-b986-4d22-a853-6de49a1c2e03@linux.ibm.com>
On Thu, 10 Jul 2025 17:41:36 +0200
Jens Remus <jremus@linux.ibm.com> wrote:
> cfa + frame->ra_off could be aligned by chance. So could
> cfa + frame->fp_off be as well of course.
>
> On s390 the CFA must be aligned (as the SP must be aligned) and the
> FP and RA offsets from CFA must be aligned, as pointer / 64-bit integers
> (such as 64-bit register values) must be aligned as well.
>
> So the CFA (and/or offset), FP offset, and RA offset could be validated
> individually. Not sure if that would be over engineering though.
I wonder if we should just validate that cfa is aligned? Would that work?
I would think that ra_off and fp_off should be aligned as well and if
cfa is aligned then it would still be aligned when adding those offsets.
-- Steve
next prev parent reply other threads:[~2025-07-10 17:09 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-07-08 1:22 [PATCH v13 00/14] unwind_user: x86: Deferred unwinding infrastructure Steven Rostedt
2025-07-08 1:22 ` [PATCH v13 01/14] unwind_user: Add user space unwinding API Steven Rostedt
2025-07-08 1:22 ` [PATCH v13 02/14] unwind_user: Add frame pointer support Steven Rostedt
2025-07-09 10:01 ` Jens Remus
2025-07-10 12:28 ` Jens Remus
2025-07-10 15:21 ` Steven Rostedt
2025-07-10 15:41 ` Jens Remus
2025-07-10 17:08 ` Steven Rostedt [this message]
2025-07-14 12:52 ` Jens Remus
2025-07-08 1:22 ` [PATCH v13 03/14] unwind_user: Add compat mode " Steven Rostedt
2025-07-08 1:22 ` [PATCH v13 04/14] unwind_user/deferred: Add unwind_user_faultable() Steven Rostedt
2025-07-08 1:22 ` [PATCH v13 05/14] unwind_user/deferred: Add unwind cache Steven Rostedt
2025-07-08 1:22 ` [PATCH v13 06/14] unwind_user/deferred: Add deferred unwinding interface Steven Rostedt
2025-07-08 1:22 ` [PATCH v13 07/14] unwind_user/deferred: Make unwind deferral requests NMI-safe Steven Rostedt
2025-07-14 13:29 ` Peter Zijlstra
2025-07-14 14:19 ` Steven Rostedt
2025-07-14 15:05 ` Peter Zijlstra
2025-07-14 15:11 ` Steven Rostedt
2025-07-15 9:09 ` Peter Zijlstra
2025-07-15 12:35 ` Steven Rostedt
2025-07-08 1:22 ` [PATCH v13 08/14] unwind deferred: Use bitmask to determine which callbacks to call Steven Rostedt
2025-07-08 1:22 ` [PATCH v13 09/14] unwind deferred: Use SRCU unwind_deferred_task_work() Steven Rostedt
2025-07-14 13:56 ` Peter Zijlstra
2025-07-14 14:21 ` Steven Rostedt
2025-07-14 15:03 ` Peter Zijlstra
2025-07-08 1:22 ` [PATCH v13 10/14] unwind: Clear unwind_mask on exit back to user space Steven Rostedt
2025-07-15 10:29 ` Peter Zijlstra
2025-07-15 12:49 ` Steven Rostedt
2025-07-15 18:06 ` Steven Rostedt
2025-07-15 18:10 ` Steven Rostedt
2025-07-15 18:26 ` Steven Rostedt
2025-07-15 19:04 ` Peter Zijlstra
2025-07-15 19:01 ` Peter Zijlstra
2025-07-15 17:20 ` Steven Rostedt
2025-07-15 19:07 ` Peter Zijlstra
2025-07-15 22:01 ` Steven Rostedt
2025-07-16 18:26 ` Steven Rostedt
2025-07-16 18:33 ` Steven Rostedt
2025-07-16 19:25 ` Steven Rostedt
2025-07-08 1:22 ` [PATCH v13 11/14] unwind: Add USED bit to only have one conditional on way " Steven Rostedt
2025-07-08 1:22 ` [PATCH v13 12/14] unwind: Finish up unwind when a task exits Steven Rostedt
2025-07-08 1:22 ` [PATCH v13 13/14] unwind_user/x86: Enable frame pointer unwinding on x86 Steven Rostedt
2025-07-11 8:43 ` David Laight
2025-07-11 16:11 ` Steven Rostedt
2025-07-08 1:22 ` [PATCH v13 14/14] unwind_user/x86: Enable compat mode " Steven Rostedt
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