linux-kernel - Re: [patch V2 20/29] tracing: Simplify stacktrace retrieval in histograms

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: <20190418094014.7d457f29@gandalf.local.home>
Date:   Thu, 18 Apr 2019 09:40:14 -0400
From:   Steven Rostedt <rostedt@...dmis.org>
To:     Thomas Gleixner <tglx@...utronix.de>,
        Tom Zanussi <tom.zanussi@...ux.intel.com>
Cc:     LKML <linux-kernel@...r.kernel.org>,
        Josh Poimboeuf <jpoimboe@...hat.com>, x86@...nel.org,
        Andy Lutomirski <luto@...nel.org>,
        Alexander Potapenko <glider@...gle.com>,
        Alexey Dobriyan <adobriyan@...il.com>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Pekka Enberg <penberg@...nel.org>, linux-mm@...ck.org,
        David Rientjes <rientjes@...gle.com>,
        Christoph Lameter <cl@...ux.com>,
        Catalin Marinas <catalin.marinas@....com>,
        Dmitry Vyukov <dvyukov@...gle.com>,
        Andrey Ryabinin <aryabinin@...tuozzo.com>,
        kasan-dev@...glegroups.com,
        Mike Rapoport <rppt@...ux.vnet.ibm.com>,
        Akinobu Mita <akinobu.mita@...il.com>,
        iommu@...ts.linux-foundation.org,
        Robin Murphy <robin.murphy@....com>,
        Christoph Hellwig <hch@....de>,
        Marek Szyprowski <m.szyprowski@...sung.com>,
        Johannes Thumshirn <jthumshirn@...e.de>,
        David Sterba <dsterba@...e.com>, Chris Mason <clm@...com>,
        Josef Bacik <josef@...icpanda.com>,
        linux-btrfs@...r.kernel.org, dm-devel@...hat.com,
        Mike Snitzer <snitzer@...hat.com>,
        Alasdair Kergon <agk@...hat.com>,
        intel-gfx@...ts.freedesktop.org,
        Joonas Lahtinen <joonas.lahtinen@...ux.intel.com>,
        Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
        dri-devel@...ts.freedesktop.org, David Airlie <airlied@...ux.ie>,
        Jani Nikula <jani.nikula@...ux.intel.com>,
        Daniel Vetter <daniel@...ll.ch>,
        Rodrigo Vivi <rodrigo.vivi@...el.com>,
        linux-arch@...r.kernel.org
Subject: Re: [patch V2 20/29] tracing: Simplify stacktrace retrieval in
 histograms


[ Added Tom Zanussi ]

On Thu, 18 Apr 2019 10:41:39 +0200
Thomas Gleixner <tglx@...utronix.de> wrote:

> The indirection through struct stack_trace is not necessary at all. Use the
> storage array based interface.
> 
> Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
> Cc: Steven Rostedt <rostedt@...dmis.org>

Looks fine to me

Acked-by: Steven Rostedt (VMware) <rostedt@...dmis.org>

 But...

Tom,

Can you review this too?

Patch series starts here:

  http://lkml.kernel.org/r/20190418084119.056416939@linutronix.de

Thanks,

-- Steve

> ---
>  kernel/trace/trace_events_hist.c |   12 +++---------
>  1 file changed, 3 insertions(+), 9 deletions(-)
> 
> --- a/kernel/trace/trace_events_hist.c
> +++ b/kernel/trace/trace_events_hist.c
> @@ -5186,7 +5186,6 @@ static void event_hist_trigger(struct ev
>  	u64 var_ref_vals[TRACING_MAP_VARS_MAX];
>  	char compound_key[HIST_KEY_SIZE_MAX];
>  	struct tracing_map_elt *elt = NULL;
> -	struct stack_trace stacktrace;
>  	struct hist_field *key_field;
>  	u64 field_contents;
>  	void *key = NULL;
> @@ -5198,14 +5197,9 @@ static void event_hist_trigger(struct ev
>  		key_field = hist_data->fields[i];
>  
>  		if (key_field->flags & HIST_FIELD_FL_STACKTRACE) {
> -			stacktrace.max_entries = HIST_STACKTRACE_DEPTH;
> -			stacktrace.entries = entries;
> -			stacktrace.nr_entries = 0;
> -			stacktrace.skip = HIST_STACKTRACE_SKIP;
> -
> -			memset(stacktrace.entries, 0, HIST_STACKTRACE_SIZE);
> -			save_stack_trace(&stacktrace);
> -
> +			memset(entries, 0, HIST_STACKTRACE_SIZE);
> +			stack_trace_save(entries, HIST_STACKTRACE_DEPTH,
> +					 HIST_STACKTRACE_SKIP);
>  			key = entries;
>  		} else {
>  			field_contents = key_field->fn(key_field, elt, rbe, rec);
>