From: Vincenzo Frascino <vincenzo.frascino@arm.com>
To: Andy Lutomirski <luto@kernel.org>
Cc: linux-arch <linux-arch@vger.kernel.org>,
linux-arm-kernel <linux-arm-kernel@lists.infradead.org>,
LKML <linux-kernel@vger.kernel.org>,
linux-mips@vger.kernel.org,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>, Paul Burton <paul.burton@mips.com>,
Thomas Gleixner <tglx@linutronix.de>,
Mark Salyzyn <salyzyn@android.com>,
Dmitry Safonov <0x7f454c46@gmail.com>
Subject: Re: [PATCH 4/7] lib: vdso: Remove VDSO_HAS_32BIT_FALLBACK
Date: Thu, 29 Aug 2019 16:51:34 +0100 [thread overview]
Message-ID: <77d5c414-77c4-49e9-3541-772c74a4735d@arm.com> (raw)
In-Reply-To: <CALCETrVprrrR3TSVSAnHfLW4HDQG=gcVrdjmsk6ss6Z3+vKOBg@mail.gmail.com>
On 29/08/2019 16:25, Andy Lutomirski wrote:
> On Thu, Aug 29, 2019 at 4:19 AM Vincenzo Frascino
> <vincenzo.frascino@arm.com> wrote:
>>
>> VDSO_HAS_32BIT_FALLBACK was introduced to address a regression which
>> caused seccomp to deny access to the applications to clock_gettime64()
>> and clock_getres64() because they are not enabled in the existing
>> filters.
>>
>> The purpose of VDSO_HAS_32BIT_FALLBACK was to simplify the conditional
>> implementation of __cvdso_clock_get*time32() variants.
>>
>> Now that all the architectures that support the generic vDSO library
>> have been converted to support the 32 bit fallbacks the conditional
>> can be removed.
>>
>> Cc: Thomas Gleixner <tglx@linutronix.de>
>> CC: Andy Lutomirski <luto@kernel.org>
>> References: c60a32ea4f45 ("lib/vdso/32: Provide legacy syscall fallbacks")
>> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
>> ---
>> lib/vdso/gettimeofday.c | 10 ----------
>> 1 file changed, 10 deletions(-)
>>
>> diff --git a/lib/vdso/gettimeofday.c b/lib/vdso/gettimeofday.c
>> index a86e89e6dedc..2c4b311c226d 100644
>> --- a/lib/vdso/gettimeofday.c
>> +++ b/lib/vdso/gettimeofday.c
>> @@ -126,13 +126,8 @@ __cvdso_clock_gettime32(clockid_t clock, struct old_timespec32 *res)
>>
>> ret = __cvdso_clock_gettime_common(clock, &ts);
>>
>> -#ifdef VDSO_HAS_32BIT_FALLBACK
>> if (unlikely(ret))
>> return clock_gettime32_fallback(clock, res);
>> -#else
>> - if (unlikely(ret))
>> - ret = clock_gettime_fallback(clock, &ts);
>> -#endif
>>
>> if (likely(!ret)) {
>> res->tv_sec = ts.tv_sec;
>
> I think you could have a little follow-up patch to remove the if
> statement -- by the time you get here, it's guaranteed that ret == 0.
>
Thanks, I will add a new patch that does that to v2 (with a comment).
> --Andy
>
--
Regards,
Vincenzo
next prev parent reply other threads:[~2019-08-29 15:51 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-29 11:18 [PATCH 0/7] vdso: Complete the conversion to 32bit syscalls Vincenzo Frascino
2019-08-29 11:18 ` [PATCH 1/7] arm64: compat: vdso: Expose BUILD_VDSO32 Vincenzo Frascino
2019-08-30 12:13 ` Catalin Marinas
2019-08-29 11:18 ` [PATCH 2/7] lib: vdso: Build 32 bit specific functions in the right context Vincenzo Frascino
2019-08-29 15:23 ` Andy Lutomirski
2019-08-29 15:48 ` Vincenzo Frascino
2019-08-29 11:18 ` [PATCH 3/7] mips: compat: vdso: Use legacy syscalls as fallback Vincenzo Frascino
2019-08-29 11:18 ` [PATCH 4/7] lib: vdso: Remove VDSO_HAS_32BIT_FALLBACK Vincenzo Frascino
2019-08-29 15:25 ` Andy Lutomirski
2019-08-29 15:51 ` Vincenzo Frascino [this message]
2019-08-29 11:18 ` [PATCH 5/7] arm64: compat: vdso: Remove unused VDSO_HAS_32BIT_FALLBACK Vincenzo Frascino
2019-08-29 12:21 ` Thomas Gleixner
2019-08-29 15:52 ` Vincenzo Frascino
2019-08-30 12:13 ` Catalin Marinas
2019-08-29 11:18 ` [PATCH 6/7] mips: " Vincenzo Frascino
2019-08-29 11:18 ` [PATCH 7/7] x86: " Vincenzo Frascino
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