linux-kernel - Re: [PATCH v2 1/4] stacktrace: add interface based on shadow call stack

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: <20220325134629.99699c921bb8c8db413e8e35@linux-foundation.org>
Date:   Fri, 25 Mar 2022 13:46:29 -0700
From:   Andrew Morton <akpm@...ux-foundation.org>
To:     andrey.konovalov@...ux.dev
Cc:     Marco Elver <elver@...gle.com>,
        Alexander Potapenko <glider@...gle.com>,
        Catalin Marinas <catalin.marinas@....com>,
        Will Deacon <will@...nel.org>,
        Andrey Konovalov <andreyknvl@...il.com>,
        Dmitry Vyukov <dvyukov@...gle.com>,
        Andrey Ryabinin <ryabinin.a.a@...il.com>,
        kasan-dev@...glegroups.com, Mark Rutland <mark.rutland@....com>,
        Vincenzo Frascino <vincenzo.frascino@....com>,
        Sami Tolvanen <samitolvanen@...gle.com>,
        Peter Collingbourne <pcc@...gle.com>,
        Evgenii Stepanov <eugenis@...gle.com>,
        Florian Mayer <fmayer@...gle.com>, linux-mm@...ck.org,
        linux-kernel@...r.kernel.org,
        Andrey Konovalov <andreyknvl@...gle.com>
Subject: Re: [PATCH v2 1/4] stacktrace: add interface based on shadow call
 stack

On Wed, 23 Mar 2022 16:32:52 +0100 andrey.konovalov@...ux.dev wrote:

> From: Andrey Konovalov <andreyknvl@...gle.com>
> 
> Add a new interface stack_trace_save_shadow() for collecting stack traces
> by copying frames from the Shadow Call Stack.
> 
> Collecting stack traces this way is significantly faster: boot time
> of a defconfig build with KASAN enabled gets descreased by ~30%.
> 
> The few patches following this one add an implementation of
> stack_trace_save_shadow() for arm64.
> 
> The implementation of the added interface is not meant to use
> stack_trace_consume_fn to avoid making a function call for each
> collected frame to further improve performance.
> 
> ...
>
> @@ -108,4 +111,16 @@ static inline int stack_trace_save_tsk_reliable(struct task_struct *tsk,
>  }
>  #endif
>  
> +#if defined(CONFIG_STACKTRACE) && defined(CONFIG_HAVE_SHADOW_STACKTRACE)
> +int stack_trace_save_shadow(unsigned long *store, unsigned int size,
> +			    unsigned int skipnr);
> +#else
> +static inline int stack_trace_save_shadow(unsigned long *store,
> +					  unsigned int size,
> +					  unsigned int skipnr)
> +{
> +	return -ENOSYS;
> +}
> +#endif

checkpatch sayeth "WARNING: ENOSYS means 'invalid syscall nr' and
nothing else".

checkpatch also picked up a typo in a changelog.  Useful thing to run,
is checkpatch.