From: "Madhavan T. Venkataraman" <madvenka@linux.microsoft.com>
To: Mark Brown <broonie@kernel.org>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>,
Miroslav Benes <mbenes@suse.cz>,
linux-arm-kernel@lists.infradead.org
Subject: Re: [RFC PATCH 0/3] arm64: Implement reliable stack trace
Date: Wed, 27 Jan 2021 08:02:41 -0600 [thread overview]
Message-ID: <6439edfb-5d4f-cf15-0059-bf7ff3bebb5c@linux.microsoft.com> (raw)
In-Reply-To: <20201012172605.10715-1-broonie@kernel.org>
On 10/12/20 12:26 PM, Mark Brown wrote:
> This patch series aims to implement reliable stacktrace for arm64.
> Reliable stacktrace exists mainly to support live patching, it provides
> a version of stacktrace that checks for consistency problems in the
> traces it generates and provides an error code to callers indicating if
> any problems were detected.
>
> This is a first cut of support for arm64, I've not really even started
> testing it meaningfully at this point. The main thing I'm looking for
> here is that I'm not sure if there are any more potential indicators of
> unrelabile stacks that I'm missing tests for or anything about the
> interfaces that I've misunderstood.
>
> There's more work that can be done here, mainly that we could sync our
> unwinder more with what's done on S/390 and x86 which should if nothing
> else help with keeping up to date with generic changes, but this should
> be what's needed to allow reliable stack trace.
>
> Mark Brown (2):
> arm64: stacktrace: Report when we reach the end of the stack
> arm64: stacktrace: Implement reliable stacktrace
>
> Mark Rutland (1):
> arm64: remove EL0 exception frame record
>
> arch/arm64/Kconfig | 1 +
> arch/arm64/kernel/entry.S | 10 +++----
> arch/arm64/kernel/stacktrace.c | 55 ++++++++++++++++++++++++++++------
> 3 files changed, 52 insertions(+), 14 deletions(-)
>
This is mostly a question to improve my understanding of the current ARM64
unwinder.
Currently, ARM64 defines different stack types - task stack, IRQ stack, etc.
When it unwinds, it appears to unwind only the currently active stack.
Specifically, if an interrupt has happened and the IRQ stack is the one that
is active, only the IRQ stack is unwound. The task stack is not. Is this
accurate?
My question is - for live patching, we would need to look at the task stack
as well, right? May be, we need to pass a flag to the unwinder to check the
task stack in addition to the active task?
Madhavan
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2021-01-27 17:04 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-12 17:26 [RFC PATCH 0/3] arm64: Implement reliable stack trace Mark Brown
2020-10-12 17:26 ` [RFC PATCH 1/3] arm64: remove EL0 exception frame record Mark Brown
2020-10-12 17:26 ` [RFC PATCH 2/3] arm64: stacktrace: Report when we reach the end of the stack Mark Brown
2020-10-13 11:07 ` Mark Rutland
2020-10-12 17:26 ` [RFC PATCH 3/3] arm64: stacktrace: Implement reliable stacktrace Mark Brown
2020-10-13 10:42 ` Mark Brown
2020-10-13 11:42 ` Mark Rutland
2020-10-13 16:12 ` Mark Brown
2020-10-15 13:33 ` Miroslav Benes
2020-10-15 15:57 ` Mark Brown
2020-10-16 10:13 ` Miroslav Benes
2020-10-16 12:30 ` Mark Brown
2020-10-15 13:39 ` [RFC PATCH 0/3] arm64: Implement reliable stack trace Miroslav Benes
2020-10-15 14:16 ` Mark Rutland
2020-10-15 15:49 ` Mark Brown
2020-10-15 21:29 ` Josh Poimboeuf
2020-10-16 11:14 ` Mark Rutland
2020-10-20 10:03 ` Mark Rutland
2020-10-20 15:58 ` Josh Poimboeuf
2020-10-16 12:15 ` Mark Brown
2020-10-19 23:41 ` Josh Poimboeuf
2020-10-20 15:39 ` Mark Brown
2020-10-20 16:28 ` Josh Poimboeuf
2021-01-27 14:02 ` Madhavan T. Venkataraman [this message]
2021-01-27 16:40 ` Mark Rutland
2021-01-27 17:11 ` Mark Brown
2021-01-27 17:24 ` Madhavan T. Venkataraman
2021-01-27 19:54 ` Madhavan T. Venkataraman
2021-01-28 14:22 ` Mark Brown
2021-01-28 15:26 ` Josh Poimboeuf
2021-01-29 21:39 ` Madhavan T. Venkataraman
2021-02-01 3:20 ` Madhavan T. Venkataraman
2021-02-01 14:39 ` Mark Brown
2021-01-30 4:38 ` Madhavan T. Venkataraman
2021-02-01 15:21 ` Madhavan T. Venkataraman
2021-02-01 15:46 ` Madhavan T. Venkataraman
2021-02-01 16:02 ` Mark Rutland
2021-02-01 16:22 ` Mark Brown
2021-02-01 21:40 ` Madhavan T. Venkataraman
2021-02-01 21:38 ` Madhavan T. Venkataraman
2021-02-01 23:00 ` Josh Poimboeuf
2021-02-02 2:29 ` Madhavan T. Venkataraman
2021-02-02 3:36 ` Josh Poimboeuf
2021-02-02 10:05 ` Mark Rutland
2021-02-02 13:33 ` Madhavan T. Venkataraman
2021-02-02 13:35 ` Madhavan T. Venkataraman
2021-02-02 23:32 ` Madhavan T. Venkataraman
2021-02-03 16:53 ` Mark Rutland
2021-02-03 19:03 ` Madhavan T. Venkataraman
2021-02-05 2:36 ` Madhavan T. Venkataraman
2021-02-01 21:59 ` Madhavan T. Venkataraman
2021-02-02 13:36 ` Mark Brown
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=6439edfb-5d4f-cf15-0059-bf7ff3bebb5c@linux.microsoft.com \
--to=madvenka@linux.microsoft.com \
--cc=broonie@kernel.org \
--cc=catalin.marinas@arm.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=mark.rutland@arm.com \
--cc=mbenes@suse.cz \
--cc=will@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).