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Subject: Re: [PATCH -next] arch/x86: Return value from notify_die should to be
 checked.
To:     Bo YU <tsu.yubo@gmail.com>, tglx@linutronix.de, mingo@redhat.com,
        bp@alien8.de, hpa@zytor.com, peterz@infradead.org, luto@kernel.org,
        jannh@google.com, dave.hansen@linux.intel.com
Cc:     linux-kernel@vger.kernel.org
References: <20200621102634.n43ozcsiravdi2ie@debian.debian-2>
From:   Alexandre Chartre <alexandre.chartre@oracle.com>
Message-ID: <4d1ef78e-f001-a685-9a69-afa68454fdc7@oracle.com>
Date:   Mon, 22 Jun 2020 10:52:23 +0200
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On 6/21/20 12:26 PM, Bo YU wrote:
> This is detected by Coverity scan: #CID: 1464472(CHECKED_RETURN)
> 
> FIXES: c94082656dac7(x86: Use enum instead of literals for trap values)
> Signed-off-by: Bo YU <tsu.yubo@gmail.com>
> ---
> arch/x86/kernel/traps.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
> index af75109485c2..bf014fb59017 100644
> --- a/arch/x86/kernel/traps.c
> +++ b/arch/x86/kernel/traps.c
> @@ -401,7 +401,8 @@ DEFINE_IDTENTRY_DF(exc_double_fault)
> 
>      nmi_enter();
>      instrumentation_begin();
> -    notify_die(DIE_TRAP, str, regs, error_code, X86_TRAP_DF, SIGSEGV);
> +    if (notify_die(DIE_TRAP, str, regs, error_code, X86_TRAP_DF, SIGSEGV))
> +        return;
> 

This change is not correct, if there's a double fault then we should die even if
notify_die() fails. So the appropriate change to make Coverity happy is probably:

  (void) notify_die(DIE_TRAP, str, regs, error_code, X86_TRAP_DF, SIGSEGV);

alex.