Re: [PATCH -next] arch/x86: Return value from notify_die should to be checked.

[Alexandre Chartre <alexandre.chartre@oracle.com>]

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.