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Date:   Fri, 15 May 2020 11:03:19 +0200 (CEST)
From:   Miroslav Benes <mbenes@suse.cz>
To:     Josh Poimboeuf <jpoimboe@redhat.com>
cc:     x86@kernel.org, linux-kernel@vger.kernel.org,
        Peter Zijlstra <peterz@infradead.org>,
        Vince Weaver <vincent.weaver@maine.edu>,
        Dave Jones <dsj@fb.com>, Jann Horn <jannh@google.com>,
        Andy Lutomirski <luto@kernel.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Pavel Machek <pavel@denx.de>
Subject: Re: [PATCH -tip urgent] x86/unwind/orc: Fix error handling in
 __unwind_start()
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References: <d6ac7215a84ca92b895fdd2e1aa546729417e6e6.1589487277.git.jpoimboe@redhat.com>
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On Thu, 14 May 2020, Josh Poimboeuf wrote:

> The unwind_state 'error' field is used to inform the reliable unwinding
> code that the stack trace can't be trusted.  Set this field for all
> errors in __unwind_start().
> 
> Also, move the zeroing out of the unwind_state struct to before the ORC
> table initialization check, to prevent the caller from reading
> uninitialized data if the ORC table is corrupted.
> 
> Fixes: af085d9084b4 ("stacktrace/x86: add function for detecting reliable stack traces")
> Fixes: d3a09104018c ("x86/unwinder/orc: Dont bail on stack overflow")
> Fixes: 98d0c8ebf77e ("x86/unwind/orc: Prevent unwinding before ORC initialization")
> Reported-by: Pavel Machek <pavel@denx.de>
> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>

Reviewed-by: Miroslav Benes <mbenes@suse.cz>

M