From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>,
Martin Schwidefsky <schwidefsky@de.ibm.com>,
Heiko Carstens <heiko.carstens@de.ibm.com>,
Vasily Gorbik <gor@linux.ibm.com>,
Sasha Levin <sashal@kernel.org>,
linux-s390@vger.kernel.org
Subject: [PATCH AUTOSEL 4.19 11/15] s390/vdso: fix vDSO clock_getres()
Date: Tue, 23 Jun 2020 13:36:26 -0400 [thread overview]
Message-ID: <20200623173630.1355971-11-sashal@kernel.org> (raw)
In-Reply-To: <20200623173630.1355971-1-sashal@kernel.org>
From: Vincenzo Frascino <vincenzo.frascino@arm.com>
[ Upstream commit 478237a595120a18e9b52fd2c57a6e8b7a01e411 ]
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 s390 vdso implementation of clock_getres keeping a copy of
hrtimer_resolution in vdso data and using that directly.
Link: https://lkml.kernel.org/r/20200324121027.21665-1-vincenzo.frascino@arm.com
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
[heiko.carstens@de.ibm.com: use llgf for proper zero extension]
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/s390/include/asm/vdso.h | 1 +
arch/s390/kernel/asm-offsets.c | 2 +-
arch/s390/kernel/time.c | 1 +
arch/s390/kernel/vdso64/clock_getres.S | 10 +++++-----
4 files changed, 8 insertions(+), 6 deletions(-)
diff --git a/arch/s390/include/asm/vdso.h b/arch/s390/include/asm/vdso.h
index 169d7604eb804..f3ba84fa9bd18 100644
--- a/arch/s390/include/asm/vdso.h
+++ b/arch/s390/include/asm/vdso.h
@@ -36,6 +36,7 @@ struct vdso_data {
__u32 tk_shift; /* Shift used for xtime_nsec 0x60 */
__u32 ts_dir; /* TOD steering direction 0x64 */
__u64 ts_end; /* TOD steering end 0x68 */
+ __u32 hrtimer_res; /* hrtimer resolution 0x70 */
};
struct vdso_per_cpu_data {
diff --git a/arch/s390/kernel/asm-offsets.c b/arch/s390/kernel/asm-offsets.c
index 66e830f1c7bfe..e9d09f6e81d25 100644
--- a/arch/s390/kernel/asm-offsets.c
+++ b/arch/s390/kernel/asm-offsets.c
@@ -75,6 +75,7 @@ int main(void)
OFFSET(__VDSO_TK_SHIFT, vdso_data, tk_shift);
OFFSET(__VDSO_TS_DIR, vdso_data, ts_dir);
OFFSET(__VDSO_TS_END, vdso_data, ts_end);
+ OFFSET(__VDSO_CLOCK_REALTIME_RES, vdso_data, hrtimer_res);
OFFSET(__VDSO_ECTG_BASE, vdso_per_cpu_data, ectg_timer_base);
OFFSET(__VDSO_ECTG_USER, vdso_per_cpu_data, ectg_user_time);
OFFSET(__VDSO_CPU_NR, vdso_per_cpu_data, cpu_nr);
@@ -86,7 +87,6 @@ int main(void)
DEFINE(__CLOCK_REALTIME_COARSE, CLOCK_REALTIME_COARSE);
DEFINE(__CLOCK_MONOTONIC_COARSE, CLOCK_MONOTONIC_COARSE);
DEFINE(__CLOCK_THREAD_CPUTIME_ID, CLOCK_THREAD_CPUTIME_ID);
- DEFINE(__CLOCK_REALTIME_RES, MONOTONIC_RES_NSEC);
DEFINE(__CLOCK_COARSE_RES, LOW_RES_NSEC);
BLANK();
/* idle data offsets */
diff --git a/arch/s390/kernel/time.c b/arch/s390/kernel/time.c
index e8766beee5ad8..8ea9db599d38d 100644
--- a/arch/s390/kernel/time.c
+++ b/arch/s390/kernel/time.c
@@ -310,6 +310,7 @@ void update_vsyscall(struct timekeeper *tk)
vdso_data->tk_mult = tk->tkr_mono.mult;
vdso_data->tk_shift = tk->tkr_mono.shift;
+ vdso_data->hrtimer_res = hrtimer_resolution;
smp_wmb();
++vdso_data->tb_update_count;
}
diff --git a/arch/s390/kernel/vdso64/clock_getres.S b/arch/s390/kernel/vdso64/clock_getres.S
index 081435398e0a1..0c79caa32b592 100644
--- a/arch/s390/kernel/vdso64/clock_getres.S
+++ b/arch/s390/kernel/vdso64/clock_getres.S
@@ -17,12 +17,14 @@
.type __kernel_clock_getres,@function
__kernel_clock_getres:
CFI_STARTPROC
- larl %r1,4f
+ larl %r1,3f
+ lg %r0,0(%r1)
cghi %r2,__CLOCK_REALTIME_COARSE
je 0f
cghi %r2,__CLOCK_MONOTONIC_COARSE
je 0f
- larl %r1,3f
+ larl %r1,_vdso_data
+ llgf %r0,__VDSO_CLOCK_REALTIME_RES(%r1)
cghi %r2,__CLOCK_REALTIME
je 0f
cghi %r2,__CLOCK_MONOTONIC
@@ -36,7 +38,6 @@ __kernel_clock_getres:
jz 2f
0: ltgr %r3,%r3
jz 1f /* res == NULL */
- lg %r0,0(%r1)
xc 0(8,%r3),0(%r3) /* set tp->tv_sec to zero */
stg %r0,8(%r3) /* store tp->tv_usec */
1: lghi %r2,0
@@ -45,6 +46,5 @@ __kernel_clock_getres:
svc 0
br %r14
CFI_ENDPROC
-3: .quad __CLOCK_REALTIME_RES
-4: .quad __CLOCK_COARSE_RES
+3: .quad __CLOCK_COARSE_RES
.size __kernel_clock_getres,.-__kernel_clock_getres
--
2.25.1
next prev parent reply other threads:[~2020-06-23 17:36 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-23 17:36 [PATCH AUTOSEL 4.19 01/15] sata_rcar: handle pm_runtime_get_sync failure cases Sasha Levin
2020-06-23 17:36 ` [PATCH AUTOSEL 4.19 02/15] ata/libata: Fix usage of page address by page_address in ata_scsi_mode_select_xlat function Sasha Levin
2020-06-23 17:36 ` [PATCH AUTOSEL 4.19 03/15] drm/amd/display: Use kfree() to free rgb_user in calculate_user_regamma_ramp() Sasha Levin
2020-06-23 17:36 ` [PATCH AUTOSEL 4.19 04/15] riscv/atomic: Fix sign extension for RV64I Sasha Levin
2020-06-23 17:36 ` [PATCH AUTOSEL 4.19 05/15] hwrng: ks-sa - Fix runtime PM imbalance on error Sasha Levin
2020-06-23 17:36 ` [PATCH AUTOSEL 4.19 06/15] arm64/sve: Eliminate data races on sve_default_vl Sasha Levin
2020-06-23 17:36 ` [PATCH AUTOSEL 4.19 07/15] ibmvnic: Harden device login requests Sasha Levin
2020-06-23 17:36 ` [PATCH AUTOSEL 4.19 08/15] net: alx: fix race condition in alx_remove Sasha Levin
2020-06-23 17:36 ` [PATCH AUTOSEL 4.19 09/15] rocker: fix incorrect error handling in dma_rings_init Sasha Levin
2020-06-23 17:36 ` [PATCH AUTOSEL 4.19 10/15] s390/ptrace: fix setting syscall number Sasha Levin
2020-06-23 17:36 ` Sasha Levin [this message]
2020-06-23 17:36 ` [PATCH AUTOSEL 4.19 12/15] arm64: sve: Fix build failure when ARM64_SVE=y and SYSCTL=n Sasha Levin
2020-06-23 17:36 ` [PATCH AUTOSEL 4.19 13/15] kbuild: improve cc-option to clean up all temporary files Sasha Levin
2020-06-23 17:36 ` [PATCH AUTOSEL 4.19 14/15] blktrace: break out of blktrace setup on concurrent calls Sasha Levin
2020-06-23 17:36 ` [PATCH AUTOSEL 4.19 15/15] RISC-V: Don't allow write+exec only page mapping request in mmap Sasha Levin
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