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Message-ID: <b48922e4-a89a-4aaf-94cf-bb2b1bff22cb@linux.ibm.com>
Date: Wed, 10 Jan 2024 15:16:58 +1100
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Subject: Re: [PATCH 09/13] powerpc: Disable KMSAN checks on functions which
 walk the stack
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To: Christophe Leroy <christophe.leroy@csgroup.eu>,
        "glider@google.com" <glider@google.com>,
        "elver@google.com"
 <elver@google.com>,
        "dvyukov@google.com" <dvyukov@google.com>,
        "akpm@linux-foundation.org" <akpm@linux-foundation.org>,
        "mpe@ellerman.id.au" <mpe@ellerman.id.au>,
        "npiggin@gmail.com" <npiggin@gmail.com>
Cc: "linux-mm@kvack.org" <linux-mm@kvack.org>,
        "kasan-dev@googlegroups.com" <kasan-dev@googlegroups.com>,
        "iii@linux.ibm.com" <iii@linux.ibm.com>,
        "linuxppc-dev@lists.ozlabs.org" <linuxppc-dev@lists.ozlabs.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
References: <20231214055539.9420-1-nicholas@linux.ibm.com>
 <20231214055539.9420-10-nicholas@linux.ibm.com>
 <e70b4365-cb0c-4565-b7b1-ac25be85c5a6@csgroup.eu>
From: Nicholas Miehlbradt <nicholas@linux.ibm.com>
In-Reply-To: <e70b4365-cb0c-4565-b7b1-ac25be85c5a6@csgroup.eu>
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On 14/12/2023 8:00 pm, Christophe Leroy wrote:
> 
> 
> Le 14/12/2023 à 06:55, Nicholas Miehlbradt a écrit :
>> Functions which walk the stack read parts of the stack which cannot be
>> instrumented by KMSAN e.g. the backchain. Disable KMSAN sanitization of
>> these functions to prevent false positives.
> 
> Do other architectures have to do it as well ?
> 
> I don't see it for show_stack(), is that a specific need for powerpc ?
> Other archs have the annotation on functions called by show_stack(). For 
x86 it's on show_trace_log_lvl() and for s390 it's on __unwind_start() 
and unwind_next_frame().