live-patching.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: "nobuta.keiya@fujitsu.com" <nobuta.keiya@fujitsu.com>
To: "'madvenka@linux.microsoft.com'" <madvenka@linux.microsoft.com>
Cc: "mark.rutland@arm.com" <mark.rutland@arm.com>,
	"broonie@kernel.org" <broonie@kernel.org>,
	"jpoimboe@redhat.com" <jpoimboe@redhat.com>,
	"ardb@kernel.org" <ardb@kernel.org>,
	"sjitindarsingh@gmail.com" <sjitindarsingh@gmail.com>,
	"catalin.marinas@arm.com" <catalin.marinas@arm.com>,
	"will@kernel.org" <will@kernel.org>,
	"jmorris@namei.org" <jmorris@namei.org>,
	"pasha.tatashin@soleen.com" <pasha.tatashin@soleen.com>,
	"jthierry@redhat.com" <jthierry@redhat.com>,
	"linux-arm-kernel@lists.infradead.org" 
	<linux-arm-kernel@lists.infradead.org>,
	"live-patching@vger.kernel.org" <live-patching@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: RE: [RFC PATCH v8 3/4] arm64: Introduce stack trace reliability checks in the unwinder
Date: Tue, 24 Aug 2021 05:55:01 +0000	[thread overview]
Message-ID: <TY2PR01MB5257EA835C6F28ABF457EB0B85C59@TY2PR01MB5257.jpnprd01.prod.outlook.com> (raw)
In-Reply-To: <20210812190603.25326-4-madvenka@linux.microsoft.com>

Hi Madhavan,

> @@ -245,7 +271,36 @@ noinline notrace void arch_stack_walk(stack_trace_consume_fn consume_entry,
>  		fp = thread_saved_fp(task);
>  		pc = thread_saved_pc(task);
>  	}
> -	unwind(consume_entry, cookie, task, fp, pc);
> +	unwind(consume_entry, cookie, task, fp, pc, false);
> +}
> +
> +/*
> + * arch_stack_walk_reliable() may not be used for livepatch until all of
> + * the reliability checks are in place in unwind_consume(). However,
> + * debug and test code can choose to use it even if all the checks are not
> + * in place.
> + */

I'm glad to see the long-awaited function :)

Does the above comment mean that this comment will be removed by
another patch series that about live patch enablement, instead of [PATCH 4/4]?

It seems to take time... But I start thinking about test code.

Thanks,
Keiya


> +noinline int notrace arch_stack_walk_reliable(stack_trace_consume_fn consume_fn,
> +					      void *cookie,
> +					      struct task_struct *task)
> +{
> +	unsigned long fp, pc;
> +
> +	if (!task)
> +		task = current;
> +
> +	if (task == current) {
> +		/* Skip arch_stack_walk_reliable() in the stack trace. */
> +		fp = (unsigned long)__builtin_frame_address(1);
> +		pc = (unsigned long)__builtin_return_address(0);
> +	} else {
> +		/* Caller guarantees that the task is not running. */
> +		fp = thread_saved_fp(task);
> +		pc = thread_saved_pc(task);
> +	}
> +	if (unwind(consume_fn, cookie, task, fp, pc, true))
> +		return 0;
> +	return -EINVAL;
>  }
> 
>  #endif
> --
> 2.25.1

  reply	other threads:[~2021-08-24  6:02 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <b45aac2843f16ca759e065ea547ab0afff8c0f01>
2021-08-12 19:05 ` [RFC PATCH v8 0/4] arm64: Reorganize the unwinder and implement stack trace reliability checks madvenka
2021-08-12 19:06   ` [RFC PATCH v8 1/4] arm64: Make all stack walking functions use arch_stack_walk() madvenka
2021-08-24 13:13     ` Mark Rutland
2021-08-24 17:21       ` Madhavan T. Venkataraman
2021-08-24 17:38         ` Madhavan T. Venkataraman
2021-08-24 17:38         ` Mark Brown
2021-08-24 17:40           ` Madhavan T. Venkataraman
2021-08-26  4:52       ` Madhavan T. Venkataraman
2021-10-09 23:41       ` Madhavan T. Venkataraman
2021-08-12 19:06   ` [RFC PATCH v8 2/4] arm64: Reorganize the unwinder code for better consistency and maintenance madvenka
2021-08-26 15:46     ` Mark Brown
2021-08-26 23:19       ` Madhavan T. Venkataraman
2021-09-01 16:20         ` Mark Brown
2021-09-02  7:10           ` Madhavan T. Venkataraman
2021-08-12 19:06   ` [RFC PATCH v8 3/4] arm64: Introduce stack trace reliability checks in the unwinder madvenka
2021-08-24  5:55     ` nobuta.keiya [this message]
2021-08-24 12:19       ` Madhavan T. Venkataraman
2021-08-25  0:01         ` nobuta.keiya
2021-08-26 15:57     ` Mark Brown
2021-08-26 23:31       ` Madhavan T. Venkataraman
2021-08-12 19:06   ` [RFC PATCH v8 4/4] arm64: Create a list of SYM_CODE functions, check return PC against list madvenka
2021-08-12 19:17   ` [RFC PATCH v8 0/4] arm64: Reorganize the unwinder and implement stack trace reliability checks Madhavan T. Venkataraman

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=TY2PR01MB5257EA835C6F28ABF457EB0B85C59@TY2PR01MB5257.jpnprd01.prod.outlook.com \
    --to=nobuta.keiya@fujitsu.com \
    --cc=ardb@kernel.org \
    --cc=broonie@kernel.org \
    --cc=catalin.marinas@arm.com \
    --cc=jmorris@namei.org \
    --cc=jpoimboe@redhat.com \
    --cc=jthierry@redhat.com \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=live-patching@vger.kernel.org \
    --cc=madvenka@linux.microsoft.com \
    --cc=mark.rutland@arm.com \
    --cc=pasha.tatashin@soleen.com \
    --cc=sjitindarsingh@gmail.com \
    --cc=will@kernel.org \
    --subject='RE: [RFC PATCH v8 3/4] arm64: Introduce stack trace reliability checks in the unwinder' \
    /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

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).