From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vincenzo Frascino Subject: [PATCH v2 1/5] arm64: Fix vDSO clock_getres() Date: Tue, 16 Apr 2019 17:14:30 +0100 Message-ID: <20190416161434.32691-2-vincenzo.frascino@arm.com> References: <20190416161434.32691-1-vincenzo.frascino@arm.com> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20190416161434.32691-1-vincenzo.frascino@arm.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linuxppc-dev-bounces+glppe-linuxppc-embedded-2=m.gmane.org@lists.ozlabs.org Sender: "Linuxppc-dev" List-Archive: List-Post: To: linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-kselftest@vger.kernel.org Cc: Arnd Bergmann , Heiko Carstens , Catalin Marinas , Will Deacon , Paul Mackerras , Greentime Hu , Martin Schwidefsky , Thomas Gleixner , Vincent Chen , Shuah Khan List-ID: clock_getres in the vDSO library has to preserve the same behaviour of posix_get_hrtimer_res(). In particular, posix_get_hrtimer_res() does: sec = 0; ns = hrtimer_resolution; and hrtimer_resolution depends on the enablement of the high resolution timers that can happen either at compile or at run time. Fix the arm64 vdso implementation of clock_getres keeping a copy of hrtimer_resolution in vdso data and using that directly. Cc: Catalin Marinas Cc: Will Deacon Signed-off-by: Vincenzo Frascino --- arch/arm64/include/asm/vdso_datapage.h | 1 + arch/arm64/kernel/asm-offsets.c | 2 +- arch/arm64/kernel/vdso.c | 2 ++ arch/arm64/kernel/vdso/gettimeofday.S | 22 +++++++++++----------- 4 files changed, 15 insertions(+), 12 deletions(-) diff --git a/arch/arm64/include/asm/vdso_datapage.h b/arch/arm64/include/asm/vdso_datapage.h index 2b9a63771eda..f89263c8e11a 100644 --- a/arch/arm64/include/asm/vdso_datapage.h +++ b/arch/arm64/include/asm/vdso_datapage.h @@ -38,6 +38,7 @@ struct vdso_data { __u32 tz_minuteswest; /* Whacky timezone stuff */ __u32 tz_dsttime; __u32 use_syscall; + __u32 hrtimer_res; }; #endif /* !__ASSEMBLY__ */ diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c index 7f40dcbdd51d..e10e2a5d9ddc 100644 --- a/arch/arm64/kernel/asm-offsets.c +++ b/arch/arm64/kernel/asm-offsets.c @@ -94,7 +94,7 @@ int main(void) DEFINE(CLOCK_REALTIME, CLOCK_REALTIME); DEFINE(CLOCK_MONOTONIC, CLOCK_MONOTONIC); DEFINE(CLOCK_MONOTONIC_RAW, CLOCK_MONOTONIC_RAW); - DEFINE(CLOCK_REALTIME_RES, MONOTONIC_RES_NSEC); + DEFINE(CLOCK_REALTIME_RES, offsetof(struct vdso_data, hrtimer_res)); DEFINE(CLOCK_REALTIME_COARSE, CLOCK_REALTIME_COARSE); DEFINE(CLOCK_MONOTONIC_COARSE,CLOCK_MONOTONIC_COARSE); DEFINE(CLOCK_COARSE_RES, LOW_RES_NSEC); diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c index 2d419006ad43..5f5759d51c33 100644 --- a/arch/arm64/kernel/vdso.c +++ b/arch/arm64/kernel/vdso.c @@ -245,6 +245,8 @@ void update_vsyscall(struct timekeeper *tk) vdso_data->cs_shift = tk->tkr_mono.shift; } + vdso_data->hrtimer_res = hrtimer_resolution; + smp_wmb(); ++vdso_data->tb_seq_count; } diff --git a/arch/arm64/kernel/vdso/gettimeofday.S b/arch/arm64/kernel/vdso/gettimeofday.S index c39872a7b03c..e2e9dfe9ba4a 100644 --- a/arch/arm64/kernel/vdso/gettimeofday.S +++ b/arch/arm64/kernel/vdso/gettimeofday.S @@ -296,32 +296,32 @@ ENDPROC(__kernel_clock_gettime) /* int __kernel_clock_getres(clockid_t clock_id, struct timespec *res); */ ENTRY(__kernel_clock_getres) .cfi_startproc + adr vdso_data, _vdso_data cmp w0, #CLOCK_REALTIME ccmp w0, #CLOCK_MONOTONIC, #0x4, ne ccmp w0, #CLOCK_MONOTONIC_RAW, #0x4, ne - b.ne 1f + b.ne 2f - ldr x2, 5f - b 2f -1: +1: /* Get hrtimer_res */ + ldr x2, [vdso_data, #CLOCK_REALTIME_RES] + b 3f +2: cmp w0, #CLOCK_REALTIME_COARSE ccmp w0, #CLOCK_MONOTONIC_COARSE, #0x4, ne - b.ne 4f + b.ne 5f ldr x2, 6f -2: - cbz x1, 3f +3: + cbz x1, 4f stp xzr, x2, [x1] -3: /* res == NULL. */ +4: /* res == NULL. */ mov w0, wzr ret -4: /* Syscall fallback. */ +5: /* Syscall fallback. */ mov x8, #__NR_clock_getres svc #0 ret -5: - .quad CLOCK_REALTIME_RES 6: .quad CLOCK_COARSE_RES .cfi_endproc -- 2.21.0 From mboxrd@z Thu Jan 1 00:00:00 1970 From: vincenzo.frascino at arm.com (Vincenzo Frascino) Date: Tue, 16 Apr 2019 17:14:30 +0100 Subject: [PATCH v2 1/5] arm64: Fix vDSO clock_getres() In-Reply-To: <20190416161434.32691-1-vincenzo.frascino@arm.com> References: <20190416161434.32691-1-vincenzo.frascino@arm.com> Message-ID: <20190416161434.32691-2-vincenzo.frascino@arm.com> clock_getres in the vDSO library has to preserve the same behaviour of posix_get_hrtimer_res(). In particular, posix_get_hrtimer_res() does: sec = 0; ns = hrtimer_resolution; and hrtimer_resolution depends on the enablement of the high resolution timers that can happen either at compile or at run time. Fix the arm64 vdso implementation of clock_getres keeping a copy of hrtimer_resolution in vdso data and using that directly. Cc: Catalin Marinas Cc: Will Deacon Signed-off-by: Vincenzo Frascino --- arch/arm64/include/asm/vdso_datapage.h | 1 + arch/arm64/kernel/asm-offsets.c | 2 +- arch/arm64/kernel/vdso.c | 2 ++ arch/arm64/kernel/vdso/gettimeofday.S | 22 +++++++++++----------- 4 files changed, 15 insertions(+), 12 deletions(-) diff --git a/arch/arm64/include/asm/vdso_datapage.h b/arch/arm64/include/asm/vdso_datapage.h index 2b9a63771eda..f89263c8e11a 100644 --- a/arch/arm64/include/asm/vdso_datapage.h +++ b/arch/arm64/include/asm/vdso_datapage.h @@ -38,6 +38,7 @@ struct vdso_data { __u32 tz_minuteswest; /* Whacky timezone stuff */ __u32 tz_dsttime; __u32 use_syscall; + __u32 hrtimer_res; }; #endif /* !__ASSEMBLY__ */ diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c index 7f40dcbdd51d..e10e2a5d9ddc 100644 --- a/arch/arm64/kernel/asm-offsets.c +++ b/arch/arm64/kernel/asm-offsets.c @@ -94,7 +94,7 @@ int main(void) DEFINE(CLOCK_REALTIME, CLOCK_REALTIME); DEFINE(CLOCK_MONOTONIC, CLOCK_MONOTONIC); DEFINE(CLOCK_MONOTONIC_RAW, CLOCK_MONOTONIC_RAW); - DEFINE(CLOCK_REALTIME_RES, MONOTONIC_RES_NSEC); + DEFINE(CLOCK_REALTIME_RES, offsetof(struct vdso_data, hrtimer_res)); DEFINE(CLOCK_REALTIME_COARSE, CLOCK_REALTIME_COARSE); DEFINE(CLOCK_MONOTONIC_COARSE,CLOCK_MONOTONIC_COARSE); DEFINE(CLOCK_COARSE_RES, LOW_RES_NSEC); diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c index 2d419006ad43..5f5759d51c33 100644 --- a/arch/arm64/kernel/vdso.c +++ b/arch/arm64/kernel/vdso.c @@ -245,6 +245,8 @@ void update_vsyscall(struct timekeeper *tk) vdso_data->cs_shift = tk->tkr_mono.shift; } + vdso_data->hrtimer_res = hrtimer_resolution; + smp_wmb(); ++vdso_data->tb_seq_count; } diff --git a/arch/arm64/kernel/vdso/gettimeofday.S b/arch/arm64/kernel/vdso/gettimeofday.S index c39872a7b03c..e2e9dfe9ba4a 100644 --- a/arch/arm64/kernel/vdso/gettimeofday.S +++ b/arch/arm64/kernel/vdso/gettimeofday.S @@ -296,32 +296,32 @@ ENDPROC(__kernel_clock_gettime) /* int __kernel_clock_getres(clockid_t clock_id, struct timespec *res); */ ENTRY(__kernel_clock_getres) .cfi_startproc + adr vdso_data, _vdso_data cmp w0, #CLOCK_REALTIME ccmp w0, #CLOCK_MONOTONIC, #0x4, ne ccmp w0, #CLOCK_MONOTONIC_RAW, #0x4, ne - b.ne 1f + b.ne 2f - ldr x2, 5f - b 2f -1: +1: /* Get hrtimer_res */ + ldr x2, [vdso_data, #CLOCK_REALTIME_RES] + b 3f +2: cmp w0, #CLOCK_REALTIME_COARSE ccmp w0, #CLOCK_MONOTONIC_COARSE, #0x4, ne - b.ne 4f + b.ne 5f ldr x2, 6f -2: - cbz x1, 3f +3: + cbz x1, 4f stp xzr, x2, [x1] -3: /* res == NULL. */ +4: /* res == NULL. */ mov w0, wzr ret -4: /* Syscall fallback. */ +5: /* Syscall fallback. */ mov x8, #__NR_clock_getres svc #0 ret -5: - .quad CLOCK_REALTIME_RES 6: .quad CLOCK_COARSE_RES .cfi_endproc -- 2.21.0 From mboxrd@z Thu Jan 1 00:00:00 1970 From: vincenzo.frascino@arm.com (Vincenzo Frascino) Date: Tue, 16 Apr 2019 17:14:30 +0100 Subject: [PATCH v2 1/5] arm64: Fix vDSO clock_getres() In-Reply-To: <20190416161434.32691-1-vincenzo.frascino@arm.com> References: <20190416161434.32691-1-vincenzo.frascino@arm.com> Message-ID: <20190416161434.32691-2-vincenzo.frascino@arm.com> Content-Type: text/plain; charset="UTF-8" Message-ID: <20190416161430.sk7lF657pi33iLAw65fhqS8Zz1KHwgd7F4K8-cRUngo@z> clock_getres in the vDSO library has to preserve the same behaviour of posix_get_hrtimer_res(). In particular, posix_get_hrtimer_res() does: sec = 0; ns = hrtimer_resolution; and hrtimer_resolution depends on the enablement of the high resolution timers that can happen either at compile or at run time. Fix the arm64 vdso implementation of clock_getres keeping a copy of hrtimer_resolution in vdso data and using that directly. Cc: Catalin Marinas Cc: Will Deacon Signed-off-by: Vincenzo Frascino --- arch/arm64/include/asm/vdso_datapage.h | 1 + arch/arm64/kernel/asm-offsets.c | 2 +- arch/arm64/kernel/vdso.c | 2 ++ arch/arm64/kernel/vdso/gettimeofday.S | 22 +++++++++++----------- 4 files changed, 15 insertions(+), 12 deletions(-) diff --git a/arch/arm64/include/asm/vdso_datapage.h b/arch/arm64/include/asm/vdso_datapage.h index 2b9a63771eda..f89263c8e11a 100644 --- a/arch/arm64/include/asm/vdso_datapage.h +++ b/arch/arm64/include/asm/vdso_datapage.h @@ -38,6 +38,7 @@ struct vdso_data { __u32 tz_minuteswest; /* Whacky timezone stuff */ __u32 tz_dsttime; __u32 use_syscall; + __u32 hrtimer_res; }; #endif /* !__ASSEMBLY__ */ diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c index 7f40dcbdd51d..e10e2a5d9ddc 100644 --- a/arch/arm64/kernel/asm-offsets.c +++ b/arch/arm64/kernel/asm-offsets.c @@ -94,7 +94,7 @@ int main(void) DEFINE(CLOCK_REALTIME, CLOCK_REALTIME); DEFINE(CLOCK_MONOTONIC, CLOCK_MONOTONIC); DEFINE(CLOCK_MONOTONIC_RAW, CLOCK_MONOTONIC_RAW); - DEFINE(CLOCK_REALTIME_RES, MONOTONIC_RES_NSEC); + DEFINE(CLOCK_REALTIME_RES, offsetof(struct vdso_data, hrtimer_res)); DEFINE(CLOCK_REALTIME_COARSE, CLOCK_REALTIME_COARSE); DEFINE(CLOCK_MONOTONIC_COARSE,CLOCK_MONOTONIC_COARSE); DEFINE(CLOCK_COARSE_RES, LOW_RES_NSEC); diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c index 2d419006ad43..5f5759d51c33 100644 --- a/arch/arm64/kernel/vdso.c +++ b/arch/arm64/kernel/vdso.c @@ -245,6 +245,8 @@ void update_vsyscall(struct timekeeper *tk) vdso_data->cs_shift = tk->tkr_mono.shift; } + vdso_data->hrtimer_res = hrtimer_resolution; + smp_wmb(); ++vdso_data->tb_seq_count; } diff --git a/arch/arm64/kernel/vdso/gettimeofday.S b/arch/arm64/kernel/vdso/gettimeofday.S index c39872a7b03c..e2e9dfe9ba4a 100644 --- a/arch/arm64/kernel/vdso/gettimeofday.S +++ b/arch/arm64/kernel/vdso/gettimeofday.S @@ -296,32 +296,32 @@ ENDPROC(__kernel_clock_gettime) /* int __kernel_clock_getres(clockid_t clock_id, struct timespec *res); */ ENTRY(__kernel_clock_getres) .cfi_startproc + adr vdso_data, _vdso_data cmp w0, #CLOCK_REALTIME ccmp w0, #CLOCK_MONOTONIC, #0x4, ne ccmp w0, #CLOCK_MONOTONIC_RAW, #0x4, ne - b.ne 1f + b.ne 2f - ldr x2, 5f - b 2f -1: +1: /* Get hrtimer_res */ + ldr x2, [vdso_data, #CLOCK_REALTIME_RES] + b 3f +2: cmp w0, #CLOCK_REALTIME_COARSE ccmp w0, #CLOCK_MONOTONIC_COARSE, #0x4, ne - b.ne 4f + b.ne 5f ldr x2, 6f -2: - cbz x1, 3f +3: + cbz x1, 4f stp xzr, x2, [x1] -3: /* res == NULL. */ +4: /* res == NULL. */ mov w0, wzr ret -4: /* Syscall fallback. */ +5: /* Syscall fallback. */ mov x8, #__NR_clock_getres svc #0 ret -5: - .quad CLOCK_REALTIME_RES 6: .quad CLOCK_COARSE_RES .cfi_endproc -- 2.21.0 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from foss.arm.com ([217.140.101.70]:58736 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726037AbfDPQOy (ORCPT ); Tue, 16 Apr 2019 12:14:54 -0400 From: Vincenzo Frascino Subject: [PATCH v2 1/5] arm64: Fix vDSO clock_getres() Date: Tue, 16 Apr 2019 17:14:30 +0100 Message-ID: <20190416161434.32691-2-vincenzo.frascino@arm.com> In-Reply-To: <20190416161434.32691-1-vincenzo.frascino@arm.com> References: <20190416161434.32691-1-vincenzo.frascino@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-arch-owner@vger.kernel.org List-ID: To: linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-kselftest@vger.kernel.org Cc: Catalin Marinas , Will Deacon , Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , Martin Schwidefsky , Heiko Carstens , Greentime Hu , Vincent Chen , Shuah Khan , Thomas Gleixner , Arnd Bergmann Message-ID: <20190416161430.2oexMgTt07dwq0dqYBJNPVwKT7oymC_A9pCfL_jmSpo@z> clock_getres in the vDSO library has to preserve the same behaviour of posix_get_hrtimer_res(). In particular, posix_get_hrtimer_res() does: sec = 0; ns = hrtimer_resolution; and hrtimer_resolution depends on the enablement of the high resolution timers that can happen either at compile or at run time. Fix the arm64 vdso implementation of clock_getres keeping a copy of hrtimer_resolution in vdso data and using that directly. Cc: Catalin Marinas Cc: Will Deacon Signed-off-by: Vincenzo Frascino --- arch/arm64/include/asm/vdso_datapage.h | 1 + arch/arm64/kernel/asm-offsets.c | 2 +- arch/arm64/kernel/vdso.c | 2 ++ arch/arm64/kernel/vdso/gettimeofday.S | 22 +++++++++++----------- 4 files changed, 15 insertions(+), 12 deletions(-) diff --git a/arch/arm64/include/asm/vdso_datapage.h b/arch/arm64/include/asm/vdso_datapage.h index 2b9a63771eda..f89263c8e11a 100644 --- a/arch/arm64/include/asm/vdso_datapage.h +++ b/arch/arm64/include/asm/vdso_datapage.h @@ -38,6 +38,7 @@ struct vdso_data { __u32 tz_minuteswest; /* Whacky timezone stuff */ __u32 tz_dsttime; __u32 use_syscall; + __u32 hrtimer_res; }; #endif /* !__ASSEMBLY__ */ diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c index 7f40dcbdd51d..e10e2a5d9ddc 100644 --- a/arch/arm64/kernel/asm-offsets.c +++ b/arch/arm64/kernel/asm-offsets.c @@ -94,7 +94,7 @@ int main(void) DEFINE(CLOCK_REALTIME, CLOCK_REALTIME); DEFINE(CLOCK_MONOTONIC, CLOCK_MONOTONIC); DEFINE(CLOCK_MONOTONIC_RAW, CLOCK_MONOTONIC_RAW); - DEFINE(CLOCK_REALTIME_RES, MONOTONIC_RES_NSEC); + DEFINE(CLOCK_REALTIME_RES, offsetof(struct vdso_data, hrtimer_res)); DEFINE(CLOCK_REALTIME_COARSE, CLOCK_REALTIME_COARSE); DEFINE(CLOCK_MONOTONIC_COARSE,CLOCK_MONOTONIC_COARSE); DEFINE(CLOCK_COARSE_RES, LOW_RES_NSEC); diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c index 2d419006ad43..5f5759d51c33 100644 --- a/arch/arm64/kernel/vdso.c +++ b/arch/arm64/kernel/vdso.c @@ -245,6 +245,8 @@ void update_vsyscall(struct timekeeper *tk) vdso_data->cs_shift = tk->tkr_mono.shift; } + vdso_data->hrtimer_res = hrtimer_resolution; + smp_wmb(); ++vdso_data->tb_seq_count; } diff --git a/arch/arm64/kernel/vdso/gettimeofday.S b/arch/arm64/kernel/vdso/gettimeofday.S index c39872a7b03c..e2e9dfe9ba4a 100644 --- a/arch/arm64/kernel/vdso/gettimeofday.S +++ b/arch/arm64/kernel/vdso/gettimeofday.S @@ -296,32 +296,32 @@ ENDPROC(__kernel_clock_gettime) /* int __kernel_clock_getres(clockid_t clock_id, struct timespec *res); */ ENTRY(__kernel_clock_getres) .cfi_startproc + adr vdso_data, _vdso_data cmp w0, #CLOCK_REALTIME ccmp w0, #CLOCK_MONOTONIC, #0x4, ne ccmp w0, #CLOCK_MONOTONIC_RAW, #0x4, ne - b.ne 1f + b.ne 2f - ldr x2, 5f - b 2f -1: +1: /* Get hrtimer_res */ + ldr x2, [vdso_data, #CLOCK_REALTIME_RES] + b 3f +2: cmp w0, #CLOCK_REALTIME_COARSE ccmp w0, #CLOCK_MONOTONIC_COARSE, #0x4, ne - b.ne 4f + b.ne 5f ldr x2, 6f -2: - cbz x1, 3f +3: + cbz x1, 4f stp xzr, x2, [x1] -3: /* res == NULL. */ +4: /* res == NULL. */ mov w0, wzr ret -4: /* Syscall fallback. */ +5: /* Syscall fallback. */ mov x8, #__NR_clock_getres svc #0 ret -5: - .quad CLOCK_REALTIME_RES 6: .quad CLOCK_COARSE_RES .cfi_endproc -- 2.21.0 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C2840C10F13 for ; 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Tue, 16 Apr 2019 09:14:51 -0700 (PDT) From: Vincenzo Frascino To: linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-kselftest@vger.kernel.org Subject: [PATCH v2 1/5] arm64: Fix vDSO clock_getres() Date: Tue, 16 Apr 2019 17:14:30 +0100 Message-Id: <20190416161434.32691-2-vincenzo.frascino@arm.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190416161434.32691-1-vincenzo.frascino@arm.com> References: <20190416161434.32691-1-vincenzo.frascino@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190416_091454_568291_570A04AD X-CRM114-Status: GOOD ( 12.72 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Benjamin Herrenschmidt , Arnd Bergmann , Heiko Carstens , Catalin Marinas , Will Deacon , Paul Mackerras , Greentime Hu , Michael Ellerman , Martin Schwidefsky , Thomas Gleixner , Vincent Chen , Shuah Khan Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org clock_getres in the vDSO library has to preserve the same behaviour of posix_get_hrtimer_res(). In particular, posix_get_hrtimer_res() does: sec = 0; ns = hrtimer_resolution; and hrtimer_resolution depends on the enablement of the high resolution timers that can happen either at compile or at run time. Fix the arm64 vdso implementation of clock_getres keeping a copy of hrtimer_resolution in vdso data and using that directly. Cc: Catalin Marinas Cc: Will Deacon Signed-off-by: Vincenzo Frascino --- arch/arm64/include/asm/vdso_datapage.h | 1 + arch/arm64/kernel/asm-offsets.c | 2 +- arch/arm64/kernel/vdso.c | 2 ++ arch/arm64/kernel/vdso/gettimeofday.S | 22 +++++++++++----------- 4 files changed, 15 insertions(+), 12 deletions(-) diff --git a/arch/arm64/include/asm/vdso_datapage.h b/arch/arm64/include/asm/vdso_datapage.h index 2b9a63771eda..f89263c8e11a 100644 --- a/arch/arm64/include/asm/vdso_datapage.h +++ b/arch/arm64/include/asm/vdso_datapage.h @@ -38,6 +38,7 @@ struct vdso_data { __u32 tz_minuteswest; /* Whacky timezone stuff */ __u32 tz_dsttime; __u32 use_syscall; + __u32 hrtimer_res; }; #endif /* !__ASSEMBLY__ */ diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c index 7f40dcbdd51d..e10e2a5d9ddc 100644 --- a/arch/arm64/kernel/asm-offsets.c +++ b/arch/arm64/kernel/asm-offsets.c @@ -94,7 +94,7 @@ int main(void) DEFINE(CLOCK_REALTIME, CLOCK_REALTIME); DEFINE(CLOCK_MONOTONIC, CLOCK_MONOTONIC); DEFINE(CLOCK_MONOTONIC_RAW, CLOCK_MONOTONIC_RAW); - DEFINE(CLOCK_REALTIME_RES, MONOTONIC_RES_NSEC); + DEFINE(CLOCK_REALTIME_RES, offsetof(struct vdso_data, hrtimer_res)); DEFINE(CLOCK_REALTIME_COARSE, CLOCK_REALTIME_COARSE); DEFINE(CLOCK_MONOTONIC_COARSE,CLOCK_MONOTONIC_COARSE); DEFINE(CLOCK_COARSE_RES, LOW_RES_NSEC); diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c index 2d419006ad43..5f5759d51c33 100644 --- a/arch/arm64/kernel/vdso.c +++ b/arch/arm64/kernel/vdso.c @@ -245,6 +245,8 @@ void update_vsyscall(struct timekeeper *tk) vdso_data->cs_shift = tk->tkr_mono.shift; } + vdso_data->hrtimer_res = hrtimer_resolution; + smp_wmb(); ++vdso_data->tb_seq_count; } diff --git a/arch/arm64/kernel/vdso/gettimeofday.S b/arch/arm64/kernel/vdso/gettimeofday.S index c39872a7b03c..e2e9dfe9ba4a 100644 --- a/arch/arm64/kernel/vdso/gettimeofday.S +++ b/arch/arm64/kernel/vdso/gettimeofday.S @@ -296,32 +296,32 @@ ENDPROC(__kernel_clock_gettime) /* int __kernel_clock_getres(clockid_t clock_id, struct timespec *res); */ ENTRY(__kernel_clock_getres) .cfi_startproc + adr vdso_data, _vdso_data cmp w0, #CLOCK_REALTIME ccmp w0, #CLOCK_MONOTONIC, #0x4, ne ccmp w0, #CLOCK_MONOTONIC_RAW, #0x4, ne - b.ne 1f + b.ne 2f - ldr x2, 5f - b 2f -1: +1: /* Get hrtimer_res */ + ldr x2, [vdso_data, #CLOCK_REALTIME_RES] + b 3f +2: cmp w0, #CLOCK_REALTIME_COARSE ccmp w0, #CLOCK_MONOTONIC_COARSE, #0x4, ne - b.ne 4f + b.ne 5f ldr x2, 6f -2: - cbz x1, 3f +3: + cbz x1, 4f stp xzr, x2, [x1] -3: /* res == NULL. */ +4: /* res == NULL. */ mov w0, wzr ret -4: /* Syscall fallback. */ +5: /* Syscall fallback. */ mov x8, #__NR_clock_getres svc #0 ret -5: - .quad CLOCK_REALTIME_RES 6: .quad CLOCK_COARSE_RES .cfi_endproc -- 2.21.0 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel