linux-kernel - Re: [PATCH 1/2] rtla/timerlat: Add --stack-format option

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CAAq0SUnNBgG=o=HrkuVDK7+nf+tjPYeoy6d1mYMyup0G8sU26w@mail.gmail.com>
Date: Wed, 21 Jan 2026 09:39:57 -0300
From: Wander Lairson Costa <wander@...hat.com>
To: Tomas Glozar <tglozar@...hat.com>
Cc: Steven Rostedt <rostedt@...dmis.org>, Costa Shulyupin <costa.shul@...hat.com>, 
	Crystal Wood <crwood@...hat.com>, John Kacur <jkacur@...hat.com>, 
	Luis Goncalves <lgoncalv@...hat.com>, LKML <linux-kernel@...r.kernel.org>, 
	Linux Trace Kernel <linux-trace-kernel@...r.kernel.org>
Subject: Re: [PATCH 1/2] rtla/timerlat: Add --stack-format option

On Mon, Jan 19, 2026 at 8:53 AM Tomas Glozar <tglozar@...hat.com> wrote:
>
> In the current implementation, the auto-analysis code for printing the
> stack captured in the tracefs buffer of the aa instance stops at the
> first encountered address that cannot be resolved into a function
> symbol.
>
> This is not always the desired behavior on all platforms; sometimes,
> there might be resolvable entries after unresolvable ones, and
> sometimes, the user might want to inspect the raw pointers for the
> unresolvable entries.
>
> Add a new option, --stack-format, with three values:
>
> - truncate: stop at first unresolvable entry. This is the current
>   behavior, and is kept as the default.
> - skip: skip unresolvable entries, but do not stop on them.
> - full: print all entries, including unresolvable ones.
>
> To make this work, the "size" field of the stack entry is now also read
> and used as the maximum number of entries to print, capped at 64, since
> that is the fixed length of the "caller" field.
>

[...]

> +int parse_stack_format(char *arg)
> +{
For the sake of function interface, it would be better to
parse_stack_format() return enum stack_format...

> +       if (!strcmp(arg, "truncate"))
> +               return STACK_FORMAT_TRUNCATE;
> +       if (!strcmp(arg, "skip"))
> +               return STACK_FORMAT_SKIP;
> +       if (!strcmp(arg, "full"))
> +               return STACK_FORMAT_FULL;
> +
> +       debug_msg("Error parsing the stack format %s\n", arg);
> +       return -1;
... and add a new entry to the enum STACK_FORMAT_INVALID = -1...

> +}
> +
>  /*
>   * parse_duration - parse duration with s/m/h/d suffix converting it to seconds
>   */
> diff --git a/tools/tracing/rtla/src/utils.h b/tools/tracing/rtla/src/utils.h
> index f7c2a52a0ab5..80d5ec0cf934 100644
> --- a/tools/tracing/rtla/src/utils.h
> +++ b/tools/tracing/rtla/src/utils.h
> @@ -62,8 +62,15 @@ struct sched_attr {
>  };
>  #endif /* SCHED_ATTR_SIZE_VER0 */
>
> +enum stack_format {
> +       STACK_FORMAT_TRUNCATE,
> +       STACK_FORMAT_SKIP,
> +       STACK_FORMAT_FULL
... here

[...]