linux-kernel - Re: [PATCH v2 5/8] lib: vdso: Remove checks on return value for 32 bit vDSO

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Date:   Fri, 30 Aug 2019 15:16:47 +0100
From:   Vincenzo Frascino <vincenzo.frascino@....com>
To:     linux-arch@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        linux-kernel@...r.kernel.org, linux-mips@...r.kernel.org,
        linux-kselftest@...r.kernel.org
Cc:     catalin.marinas@....com, 0x7f454c46@...il.com, salyzyn@...roid.com,
        paul.burton@...s.com, luto@...nel.org, tglx@...utronix.de,
        will@...nel.org
Subject: Re: [PATCH v2 5/8] lib: vdso: Remove checks on return value for 32
 bit vDSO

On 30/08/2019 14:58, Vincenzo Frascino wrote:
> Since all the architectures that support the generic vDSO library have
> been converted to support the 32 bit fallbacks it is not required
> anymore to check the return value of __cvdso_clock_get*time32_common()
> before updating the old_timespec fields.
> 
> Remove the related checks from the generic vdso library.
> 
> Cc: Thomas Gleixner <tglx@...utronix.de>
> CC: Andy Lutomirski <luto@...nel.org>

Forgot to add to this patch:

Suggested-by: Andy Lutomirski <luto@...nel.org>

> References: c60a32ea4f45 ("lib/vdso/32: Provide legacy syscall fallbacks")
> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@....com>
> ---
>  lib/vdso/gettimeofday.c | 16 ++++++++--------
>  1 file changed, 8 insertions(+), 8 deletions(-)
> 
> diff --git a/lib/vdso/gettimeofday.c b/lib/vdso/gettimeofday.c
> index 2c4b311c226d..d5bc16748f81 100644
> --- a/lib/vdso/gettimeofday.c
> +++ b/lib/vdso/gettimeofday.c
> @@ -129,10 +129,10 @@ __cvdso_clock_gettime32(clockid_t clock, struct old_timespec32 *res)
>  	if (unlikely(ret))
>  		return clock_gettime32_fallback(clock, res);
>  
> -	if (likely(!ret)) {
> -		res->tv_sec = ts.tv_sec;
> -		res->tv_nsec = ts.tv_nsec;
> -	}
> +	/* For ret == 0 */
> +	res->tv_sec = ts.tv_sec;
> +	res->tv_nsec = ts.tv_nsec;
> +
>  	return ret;
>  }
>  #endif /* BUILD_VDSO32 */
> @@ -238,10 +238,10 @@ __cvdso_clock_getres_time32(clockid_t clock, struct old_timespec32 *res)
>  	if (unlikely(ret))
>  		return clock_getres32_fallback(clock, res);
>  
> -	if (likely(!ret)) {
> -		res->tv_sec = ts.tv_sec;
> -		res->tv_nsec = ts.tv_nsec;
> -	}
> +	/* For ret == 0 */
> +	res->tv_sec = ts.tv_sec;
> +	res->tv_nsec = ts.tv_nsec;
> +
>  	return ret;
>  }
>  #endif /* BUILD_VDSO32 */
> 

-- 
Regards,
Vincenzo