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 powerpc vdso implementation of clock_getres keeping a copy of hrtimer_resolution in vdso data and using that directly.

Fixes: a7f290dad32e ("[PATCH] powerpc: Merge vdso's and add vdso support to 32 bits kernel") Cc: stable@vger.kernel.org Cc: Benjamin Herrenschmidt benh@kernel.crashing.org Cc: Paul Mackerras paulus@samba.org Cc: Michael Ellerman mpe@ellerman.id.au Signed-off-by: Vincenzo Frascino vincenzo.frascino@arm.com Reviewed-by: Christophe Leroy christophe.leroy@c-s.fr ---

Note: This patch is independent from the others in this series, hence it can be merged singularly by the powerpc maintainers.

arch/powerpc/include/asm/vdso_datapage.h | 2 ++ arch/powerpc/kernel/asm-offsets.c | 2 +- arch/powerpc/kernel/time.c | 1 + arch/powerpc/kernel/vdso32/gettimeofday.S | 7 +++++-- arch/powerpc/kernel/vdso64/gettimeofday.S | 7 +++++-- 5 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/arch/powerpc/include/asm/vdso_datapage.h b/arch/powerpc/include/asm/vdso_datapage.h index bbc06bd72b1f..4333b9a473dc 100644 --- a/arch/powerpc/include/asm/vdso_datapage.h +++ b/arch/powerpc/include/asm/vdso_datapage.h @@ -86,6 +86,7 @@ struct vdso_data { __s32 wtom_clock_nsec; /* Wall to monotonic clock nsec */ __s64 wtom_clock_sec; /* Wall to monotonic clock sec */ struct timespec stamp_xtime; /* xtime as at tb_orig_stamp */ + __u32 hrtimer_res; /* hrtimer resolution */ __u32 syscall_map_64[SYSCALL_MAP_SIZE]; /* map of syscalls */ __u32 syscall_map_32[SYSCALL_MAP_SIZE]; /* map of syscalls */ }; @@ -107,6 +108,7 @@ struct vdso_data { __s32 wtom_clock_nsec; struct timespec stamp_xtime; /* xtime as at tb_orig_stamp */ __u32 stamp_sec_fraction; /* fractional seconds of stamp_xtime */ + __u32 hrtimer_res; /* hrtimer resolution */ __u32 syscall_map_32[SYSCALL_MAP_SIZE]; /* map of syscalls */ __u32 dcache_block_size; /* L1 d-cache block size */ __u32 icache_block_size; /* L1 i-cache block size */ diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c index 8e02444e9d3d..dfc40f29f2b9 100644 --- a/arch/powerpc/kernel/asm-offsets.c +++ b/arch/powerpc/kernel/asm-offsets.c @@ -389,6 +389,7 @@ int main(void) OFFSET(WTOM_CLOCK_NSEC, vdso_data, wtom_clock_nsec); OFFSET(STAMP_XTIME, vdso_data, stamp_xtime); OFFSET(STAMP_SEC_FRAC, vdso_data, stamp_sec_fraction); + OFFSET(CLOCK_REALTIME_RES, vdso_data, hrtimer_res); OFFSET(CFG_ICACHE_BLOCKSZ, vdso_data, icache_block_size); OFFSET(CFG_DCACHE_BLOCKSZ, vdso_data, dcache_block_size); OFFSET(CFG_ICACHE_LOGBLOCKSZ, vdso_data, icache_log_block_size); @@ -419,7 +420,6 @@ int main(void) DEFINE(CLOCK_REALTIME_COARSE, CLOCK_REALTIME_COARSE); DEFINE(CLOCK_MONOTONIC_COARSE, CLOCK_MONOTONIC_COARSE); DEFINE(NSEC_PER_SEC, NSEC_PER_SEC); - DEFINE(CLOCK_REALTIME_RES, MONOTONIC_RES_NSEC);

#ifdef CONFIG_BUG DEFINE(BUG_ENTRY_SIZE, sizeof(struct bug_entry)); diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c index 325d60633dfa..4ea4e9d7a58e 100644 --- a/arch/powerpc/kernel/time.c +++ b/arch/powerpc/kernel/time.c @@ -963,6 +963,7 @@ void update_vsyscall(struct timekeeper *tk) vdso_data->wtom_clock_nsec = tk->wall_to_monotonic.tv_nsec; vdso_data->stamp_xtime = xt; vdso_data->stamp_sec_fraction = frac_sec; + vdso_data->hrtimer_res = hrtimer_resolution; smp_wmb(); ++(vdso_data->tb_update_count); } diff --git a/arch/powerpc/kernel/vdso32/gettimeofday.S b/arch/powerpc/kernel/vdso32/gettimeofday.S index afd516b572f8..2b5f9e83c610 100644 --- a/arch/powerpc/kernel/vdso32/gettimeofday.S +++ b/arch/powerpc/kernel/vdso32/gettimeofday.S @@ -160,12 +160,15 @@ V_FUNCTION_BEGIN(__kernel_clock_getres) cror cr0*4+eq,cr0*4+eq,cr1*4+eq bne cr0,99f

+ mflr r12 + .cfi_register lr,r12 + bl __get_datapage@local + lwz r5,CLOCK_REALTIME_RES(r3) + mtlr r12 li r3,0 cmpli cr0,r4,0 crclr cr0*4+so beqlr - lis r5,CLOCK_REALTIME_RES@h - ori r5,r5,CLOCK_REALTIME_RES@l stw r3,TSPC32_TV_SEC(r4) stw r5,TSPC32_TV_NSEC(r4) blr diff --git a/arch/powerpc/kernel/vdso64/gettimeofday.S b/arch/powerpc/kernel/vdso64/gettimeofday.S index 1f324c28705b..f07730f73d5e 100644 --- a/arch/powerpc/kernel/vdso64/gettimeofday.S +++ b/arch/powerpc/kernel/vdso64/gettimeofday.S @@ -190,12 +190,15 @@ V_FUNCTION_BEGIN(__kernel_clock_getres) cror cr0*4+eq,cr0*4+eq,cr1*4+eq bne cr0,99f

+ mflr r12 + .cfi_register lr,r12 + bl V_LOCAL_FUNC(__get_datapage) + lwz r5,CLOCK_REALTIME_RES(r3) + mtlr r12 li r3,0 cmpldi cr0,r4,0 crclr cr0*4+so beqlr - lis r5,CLOCK_REALTIME_RES@h - ori r5,r5,CLOCK_REALTIME_RES@l std r3,TSPC64_TV_SEC(r4) std r5,TSPC64_TV_NSEC(r4) blr

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.

Cc: Martin Schwidefsky schwidefsky@de.ibm.com Cc: Heiko Carstens heiko.carstens@de.ibm.com Signed-off-by: Vincenzo Frascino vincenzo.frascino@arm.com Acked-by: Martin Schwidefsky schwidefsky@de.ibm.com ---

Note: This patch is independent from the others in this series, hence it can be merged singularly by the s390 maintainers.

arch/s390/include/asm/vdso.h | 1 + arch/s390/kernel/asm-offsets.c | 2 +- arch/s390/kernel/time.c | 1 + arch/s390/kernel/vdso32/clock_getres.S | 12 +++++++----- arch/s390/kernel/vdso64/clock_getres.S | 10 +++++----- 5 files changed, 15 insertions(+), 11 deletions(-)

diff --git a/arch/s390/include/asm/vdso.h b/arch/s390/include/asm/vdso.h index 169d7604eb80..f3ba84fa9bd1 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 41ac4ad21311..4a229a60b24a 100644 --- a/arch/s390/kernel/asm-offsets.c +++ b/arch/s390/kernel/asm-offsets.c @@ -76,6 +76,7 @@ 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); @@ -87,7 +88,6 @@ 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 e8766beee5ad..8ea9db599d38 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/vdso32/clock_getres.S b/arch/s390/kernel/vdso32/clock_getres.S index eaf9cf1417f6..fecd7684c645 100644 --- a/arch/s390/kernel/vdso32/clock_getres.S +++ b/arch/s390/kernel/vdso32/clock_getres.S @@ -18,20 +18,22 @@ __kernel_clock_getres: CFI_STARTPROC basr %r1,0 - la %r1,4f-.(%r1) +10: al %r1,4f-10b(%r1) + l %r0,__VDSO_CLOCK_REALTIME_RES(%r1) chi %r2,__CLOCK_REALTIME je 0f chi %r2,__CLOCK_MONOTONIC je 0f - la %r1,5f-4f(%r1) + basr %r1,0 + la %r1,5f-.(%r1) + l %r0,0(%r1) chi %r2,__CLOCK_REALTIME_COARSE je 0f chi %r2,__CLOCK_MONOTONIC_COARSE jne 3f 0: ltr %r3,%r3 jz 2f /* res == NULL */ -1: l %r0,0(%r1) - xc 0(4,%r3),0(%r3) /* set tp->tv_sec to zero */ +1: xc 0(4,%r3),0(%r3) /* set tp->tv_sec to zero */ st %r0,4(%r3) /* store tp->tv_usec */ 2: lhi %r2,0 br %r14 @@ -39,6 +41,6 @@ __kernel_clock_getres: svc 0 br %r14 CFI_ENDPROC -4: .long __CLOCK_REALTIME_RES +4: .long _vdso_data - 10b 5: .long __CLOCK_COARSE_RES .size __kernel_clock_getres,.-__kernel_clock_getres diff --git a/arch/s390/kernel/vdso64/clock_getres.S b/arch/s390/kernel/vdso64/clock_getres.S index 081435398e0a..022b58c980db 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 + l %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

The current version of the multiarch vDSO selftest verifies only gettimeofday.

Extend the vDSO selftest to clock_getres, to verify that the syscall and the vDSO library function return the same information.

The extension has been used to verify the hrtimer_resoltion fix.

Cc: Shuah Khan shuah@kernel.org Signed-off-by: Vincenzo Frascino vincenzo.frascino@arm.com ---

Note: This patch is independent from the others in this series, hence it can be merged singularly by the kselftest maintainers.

tools/testing/selftests/vDSO/Makefile | 2 + .../selftests/vDSO/vdso_clock_getres.c | 124 ++++++++++++++++++ 2 files changed, 126 insertions(+) create mode 100644 tools/testing/selftests/vDSO/vdso_clock_getres.c

diff --git a/tools/testing/selftests/vDSO/Makefile b/tools/testing/selftests/vDSO/Makefile index 9e03d61f52fd..d5c5bfdf1ac1 100644 --- a/tools/testing/selftests/vDSO/Makefile +++ b/tools/testing/selftests/vDSO/Makefile @@ -5,6 +5,7 @@ uname_M := $(shell uname -m 2>/dev/null || echo not) ARCH ?= $(shell echo $(uname_M) | sed -e s/i.86/x86/ -e s/x86_64/x86/)

TEST_GEN_PROGS := $(OUTPUT)/vdso_test +TEST_GEN_PROGS += $(OUTPUT)/vdso_clock_getres ifeq ($(ARCH),x86) TEST_GEN_PROGS += $(OUTPUT)/vdso_standalone_test_x86 endif @@ -18,6 +19,7 @@ endif

all: $(TEST_GEN_PROGS) $(OUTPUT)/vdso_test: parse_vdso.c vdso_test.c +$(OUTPUT)/vdso_clock_getres: vdso_clock_getres.c $(OUTPUT)/vdso_standalone_test_x86: vdso_standalone_test_x86.c parse_vdso.c $(CC) $(CFLAGS) $(CFLAGS_vdso_standalone_test_x86) \ vdso_standalone_test_x86.c parse_vdso.c \ diff --git a/tools/testing/selftests/vDSO/vdso_clock_getres.c b/tools/testing/selftests/vDSO/vdso_clock_getres.c new file mode 100644 index 000000000000..15dcee16ff72 --- /dev/null +++ b/tools/testing/selftests/vDSO/vdso_clock_getres.c @@ -0,0 +1,124 @@ +// SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note +/* + * vdso_clock_getres.c: Sample code to test clock_getres. + * Copyright (c) 2019 Arm Ltd. + * + * Compile with: + * gcc -std=gnu99 vdso_clock_getres.c + * + * Tested on ARM, ARM64, MIPS32, x86 (32-bit and 64-bit), + * Power (32-bit and 64-bit), S390x (32-bit and 64-bit). + * Might work on other architectures. + */ + +#define _GNU_SOURCE +#include <elf.h> +#include <err.h> +#include <fcntl.h> +#include <stdint.h> +#include <stdio.h> +#include <stdlib.h> +#include <time.h> +#include <sys/auxv.h> +#include <sys/mman.h> +#include <sys/time.h> +#include <unistd.h> +#include <sys/syscall.h> + +#include "../kselftest.h" + +static long syscall_clock_getres(clockid_t _clkid, struct timespec *_ts) +{ + long ret; + + ret = syscall(SYS_clock_getres, _clkid, _ts); + + return ret; +} + +const char *vdso_clock_name[12] = { + "CLOCK_REALTIME", + "CLOCK_MONOTONIC", + "CLOCK_PROCESS_CPUTIME_ID", + "CLOCK_THREAD_CPUTIME_ID", + "CLOCK_MONOTONIC_RAW", + "CLOCK_REALTIME_COARSE", + "CLOCK_MONOTONIC_COARSE", + "CLOCK_BOOTTIME", + "CLOCK_REALTIME_ALARM", + "CLOCK_BOOTTIME_ALARM", + "CLOCK_SGI_CYCLE", + "CLOCK_TAI", +}; + +/* + * This function calls clock_getres in vdso and by system call + * with different values for clock_id. + * + * Example of output: + * + * clock_id: CLOCK_REALTIME [PASS] + * clock_id: CLOCK_BOOTTIME [PASS] + * clock_id: CLOCK_TAI [PASS] + * clock_id: CLOCK_REALTIME_COARSE [PASS] + * clock_id: CLOCK_MONOTONIC [PASS] + * clock_id: CLOCK_MONOTONIC_RAW [PASS] + * clock_id: CLOCK_MONOTONIC_COARSE [PASS] + */ +static inline int vdso_test_clock(unsigned int clock_id) +{ + struct timespec x, y; + + printf("clock_id: %s", vdso_clock_name[clock_id]); + clock_getres(clock_id, &x); + syscall_clock_getres(clock_id, &y); + + if ((x.tv_sec != y.tv_sec) || (x.tv_nsec != y.tv_nsec)) { + printf(" [FAIL]\n"); + return KSFT_FAIL; + } + + printf(" [PASS]\n"); + return KSFT_PASS; +} + +int main(int argc, char **argv) +{ + int ret; + +#if _POSIX_TIMERS > 0 + +#ifdef CLOCK_REALTIME + ret = vdso_test_clock(CLOCK_REALTIME); +#endif + +#ifdef CLOCK_BOOTTIME + ret += vdso_test_clock(CLOCK_BOOTTIME); +#endif + +#ifdef CLOCK_TAI + ret += vdso_test_clock(CLOCK_TAI); +#endif + +#ifdef CLOCK_REALTIME_COARSE + ret += vdso_test_clock(CLOCK_REALTIME_COARSE); +#endif + +#ifdef CLOCK_MONOTONIC + ret += vdso_test_clock(CLOCK_MONOTONIC); +#endif + +#ifdef CLOCK_MONOTONIC_RAW + ret += vdso_test_clock(CLOCK_MONOTONIC_RAW); +#endif + +#ifdef CLOCK_MONOTONIC_COARSE + ret += vdso_test_clock(CLOCK_MONOTONIC_COARSE); +#endif + +#endif + if (ret > 0) + return KSFT_FAIL; + + return KSFT_PASS; +}