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In-Reply-To: <317123b5c05e2f82854fc55d8b285e0869d3cb77.1676063693.git.andreyknvl@google.com>
From:   Alexander Potapenko <glider@google.com>
Date:   Mon, 13 Feb 2023 12:40:10 +0100
Message-ID: <CAG_fn=W+DHE557+u66qAUbo9tjL6qgcktEJPfTCzFRAE7Ckd5A@mail.gmail.com>
Subject: Re: [PATCH v2 15/18] lib/stacktrace, kasan, kmsan: rework extra_bits interface
To:     andrey.konovalov@linux.dev
Cc:     Marco Elver <elver@google.com>,
        Andrey Konovalov <andreyknvl@gmail.com>,
        Vlastimil Babka <vbabka@suse.cz>, kasan-dev@googlegroups.com,
        Evgenii Stepanov <eugenis@google.com>,
        Andrew Morton <akpm@linux-foundation.org>, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org,
        Andrey Konovalov <andreyknvl@google.com>
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On Fri, Feb 10, 2023 at 10:18 PM <andrey.konovalov@linux.dev> wrote:
>
> From: Andrey Konovalov <andreyknvl@google.com>
>
> The current implementation of the extra_bits interface is confusing:
> passing extra_bits to __stack_depot_save makes it seem that the extra
> bits are somehow stored in stack depot. In reality, they are only
> embedded into a stack depot handle and are not used within stack depot.
>
> Drop the extra_bits argument from __stack_depot_save and instead provide
> a new stack_depot_set_extra_bits function (similar to the exsiting
> stack_depot_get_extra_bits) that saves extra bits into a stack depot
> handle.
>
> Update the callers of __stack_depot_save to use the new interace.
>
> This change also fixes a minor issue in the old code: __stack_depot_save
> does not return NULL if saving stack trace fails and extra_bits is used.
>
> Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>