[PATCH 0/5] Fix vDSO clock_getres()

[PATCH 0/5] Fix vDSO clock_getres()

[Vincenzo Frascino]

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.

A possible fix is to change the vdso implementation of clock_getres,
keeping a copy of hrtimer_resolution in vdso data and using that
directly [1].

This patchset implements the proposed fix for arm64, powerpc, s390,
nds32 and adds a test to verify that the syscall and the vdso library
implementation of clock_getres return the same values.

[1] https://marc.info/?l=linux-arm-kernel&m=155110381930196&w=2 

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>

Vincenzo Frascino (5):
  arm64: Fix vDSO clock_getres()
  powerpc: Fix vDSO clock_getres()
  s390: Fix vDSO clock_getres()
  nds32: Fix vDSO clock_getres()
  kselftest: Extend vDSO selftest to clock_getres

 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         |  25 ++--
 arch/nds32/include/asm/vdso_datapage.h        |   1 +
 arch/nds32/kernel/vdso.c                      |   1 +
 arch/nds32/kernel/vdso/gettimeofday.c         |   4 +-
 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     |  22 ++--
 arch/powerpc/kernel/vdso64/gettimeofday.S     |  22 ++--
 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        |  17 ++-
 arch/s390/kernel/vdso64/clock_getres.S        |  15 ++-
 tools/testing/selftests/vDSO/Makefile         |   2 +
 .../selftests/vDSO/vdso_clock_getres.c        | 107 ++++++++++++++++++
 19 files changed, 191 insertions(+), 39 deletions(-)
 create mode 100644 tools/testing/selftests/vDSO/vdso_clock_getres.c

-- 
2.21.0

[PATCH 0/5] Fix vDSO clock_getres()

[Vincenzo Frascino]

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.

A possible fix is to change the vdso implementation of clock_getres,
keeping a copy of hrtimer_resolution in vdso data and using that
directly [1].

This patchset implements the proposed fix for arm64, powerpc, s390,
nds32 and adds a test to verify that the syscall and the vdso library
implementation of clock_getres return the same values.

[1] https://marc.info/?l=linux-arm-kernel&m=155110381930196&w=2 

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>

Vincenzo Frascino (5):
  arm64: Fix vDSO clock_getres()
  powerpc: Fix vDSO clock_getres()
  s390: Fix vDSO clock_getres()
  nds32: Fix vDSO clock_getres()
  kselftest: Extend vDSO selftest to clock_getres

 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         |  25 ++--
 arch/nds32/include/asm/vdso_datapage.h        |   1 +
 arch/nds32/kernel/vdso.c                      |   1 +
 arch/nds32/kernel/vdso/gettimeofday.c         |   4 +-
 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     |  22 ++--
 arch/powerpc/kernel/vdso64/gettimeofday.S     |  22 ++--
 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        |  17 ++-
 arch/s390/kernel/vdso64/clock_getres.S        |  15 ++-
 tools/testing/selftests/vDSO/Makefile         |   2 +
 .../selftests/vDSO/vdso_clock_getres.c        | 107 ++++++++++++++++++
 19 files changed, 191 insertions(+), 39 deletions(-)
 create mode 100644 tools/testing/selftests/vDSO/vdso_clock_getres.c

-- 
2.21.0


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH 0/5] Fix vDSO clock_getres()

[Vincenzo Frascino]

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.

A possible fix is to change the vdso implementation of clock_getres,
keeping a copy of hrtimer_resolution in vdso data and using that
directly [1].

This patchset implements the proposed fix for arm64, powerpc, s390,
nds32 and adds a test to verify that the syscall and the vdso library
implementation of clock_getres return the same values.

[1] https://marc.info/?l=linux-arm-kernel&m=155110381930196&w=2 

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>

Vincenzo Frascino (5):
  arm64: Fix vDSO clock_getres()
  powerpc: Fix vDSO clock_getres()
  s390: Fix vDSO clock_getres()
  nds32: Fix vDSO clock_getres()
  kselftest: Extend vDSO selftest to clock_getres

 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         |  25 ++--
 arch/nds32/include/asm/vdso_datapage.h        |   1 +
 arch/nds32/kernel/vdso.c                      |   1 +
 arch/nds32/kernel/vdso/gettimeofday.c         |   4 +-
 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     |  22 ++--
 arch/powerpc/kernel/vdso64/gettimeofday.S     |  22 ++--
 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        |  17 ++-
 arch/s390/kernel/vdso64/clock_getres.S        |  15 ++-
 tools/testing/selftests/vDSO/Makefile         |   2 +
 .../selftests/vDSO/vdso_clock_getres.c        | 107 ++++++++++++++++++
 19 files changed, 191 insertions(+), 39 deletions(-)
 create mode 100644 tools/testing/selftests/vDSO/vdso_clock_getres.c

-- 
2.21.0

[PATCH 0/5] Fix vDSO clock_getres()

[Vincenzo Frascino]

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.

A possible fix is to change the vdso implementation of clock_getres,
keeping a copy of hrtimer_resolution in vdso data and using that
directly [1].

This patchset implements the proposed fix for arm64, powerpc, s390,
nds32 and adds a test to verify that the syscall and the vdso library
implementation of clock_getres return the same values.

[1] https://marc.info/?l=linux-arm-kernel&m=155110381930196&w=2 

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>

Vincenzo Frascino (5):
  arm64: Fix vDSO clock_getres()
  powerpc: Fix vDSO clock_getres()
  s390: Fix vDSO clock_getres()
  nds32: Fix vDSO clock_getres()
  kselftest: Extend vDSO selftest to clock_getres

 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         |  25 ++--
 arch/nds32/include/asm/vdso_datapage.h        |   1 +
 arch/nds32/kernel/vdso.c                      |   1 +
 arch/nds32/kernel/vdso/gettimeofday.c         |   4 +-
 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     |  22 ++--
 arch/powerpc/kernel/vdso64/gettimeofday.S     |  22 ++--
 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        |  17 ++-
 arch/s390/kernel/vdso64/clock_getres.S        |  15 ++-
 tools/testing/selftests/vDSO/Makefile         |   2 +
 .../selftests/vDSO/vdso_clock_getres.c        | 107 ++++++++++++++++++
 19 files changed, 191 insertions(+), 39 deletions(-)
 create mode 100644 tools/testing/selftests/vDSO/vdso_clock_getres.c

-- 
2.21.0

[PATCH 1/5] arm64: Fix vDSO clock_getres()

[Vincenzo Frascino]

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 <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
---
 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  | 25 ++++++++++++++-----------
 4 files changed, 18 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..47ba72345739 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..7a2cd2f8e13a 100644
--- a/arch/arm64/kernel/vdso/gettimeofday.S
+++ b/arch/arm64/kernel/vdso/gettimeofday.S
@@ -296,32 +296,35 @@ 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 */
+	seqcnt_acquire
+	syscall_check fail=5f
+	ldr	x2, [vdso_data, #CLOCK_REALTIME_RES]
+	seqcnt_check fail=1b
+	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

[PATCH 1/5] arm64: Fix vDSO clock_getres()

[Vincenzo Frascino]

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 <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
---
 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  | 25 ++++++++++++++-----------
 4 files changed, 18 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..47ba72345739 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..7a2cd2f8e13a 100644
--- a/arch/arm64/kernel/vdso/gettimeofday.S
+++ b/arch/arm64/kernel/vdso/gettimeofday.S
@@ -296,32 +296,35 @@ 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 */
+	seqcnt_acquire
+	syscall_check fail=5f
+	ldr	x2, [vdso_data, #CLOCK_REALTIME_RES]
+	seqcnt_check fail=1b
+	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

[PATCH 1/5] arm64: Fix vDSO clock_getres()

[Vincenzo Frascino]

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 <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
---
 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  | 25 ++++++++++++++-----------
 4 files changed, 18 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..47ba72345739 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..7a2cd2f8e13a 100644
--- a/arch/arm64/kernel/vdso/gettimeofday.S
+++ b/arch/arm64/kernel/vdso/gettimeofday.S
@@ -296,32 +296,35 @@ 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 */
+	seqcnt_acquire
+	syscall_check fail=5f
+	ldr	x2, [vdso_data, #CLOCK_REALTIME_RES]
+	seqcnt_check fail=1b
+	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

[PATCH 1/5] arm64: Fix vDSO clock_getres()

[Vincenzo Frascino]

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 <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
---
 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  | 25 ++++++++++++++-----------
 4 files changed, 18 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..47ba72345739 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..7a2cd2f8e13a 100644
--- a/arch/arm64/kernel/vdso/gettimeofday.S
+++ b/arch/arm64/kernel/vdso/gettimeofday.S
@@ -296,32 +296,35 @@ 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 */
+	seqcnt_acquire
+	syscall_check fail=5f
+	ldr	x2, [vdso_data, #CLOCK_REALTIME_RES]
+	seqcnt_check fail=1b
+	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

Re: [PATCH 1/5] arm64: Fix vDSO clock_getres()

[Catalin Marinas]

On Mon, Apr 01, 2019 at 12:51:48PM +0100, Vincenzo Frascino wrote:
> diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c
> index 2d419006ad43..47ba72345739 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..7a2cd2f8e13a 100644
> --- a/arch/arm64/kernel/vdso/gettimeofday.S
> +++ b/arch/arm64/kernel/vdso/gettimeofday.S
> @@ -296,32 +296,35 @@ 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 */
> +	seqcnt_acquire
> +	syscall_check fail=5f
> +	ldr	x2, [vdso_data, #CLOCK_REALTIME_RES]
> +	seqcnt_check fail=1b
> +	b	3f
> +2:

We talked briefly but I'm still confused why we need the fallback to the
syscall here if archdata.vdso_direct is false. Is it because if the
timer driver code sets vdso_direct to false, we don't don't support
highres timers? If my understanding is correct, you may want to move the
hrtimer_res setting in update_vsyscall() to the !use_syscall block.

-- 
Catalin

Re: [PATCH 1/5] arm64: Fix vDSO clock_getres()

[Catalin Marinas]

On Mon, Apr 01, 2019 at 12:51:48PM +0100, Vincenzo Frascino wrote:
> diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c
> index 2d419006ad43..47ba72345739 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..7a2cd2f8e13a 100644
> --- a/arch/arm64/kernel/vdso/gettimeofday.S
> +++ b/arch/arm64/kernel/vdso/gettimeofday.S
> @@ -296,32 +296,35 @@ 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 */
> +	seqcnt_acquire
> +	syscall_check fail=5f
> +	ldr	x2, [vdso_data, #CLOCK_REALTIME_RES]
> +	seqcnt_check fail=1b
> +	b	3f
> +2:

We talked briefly but I'm still confused why we need the fallback to the
syscall here if archdata.vdso_direct is false. Is it because if the
timer driver code sets vdso_direct to false, we don't don't support
highres timers? If my understanding is correct, you may want to move the
hrtimer_res setting in update_vsyscall() to the !use_syscall block.

-- 
Catalin

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Re: [PATCH 1/5] arm64: Fix vDSO clock_getres()

[Catalin Marinas]

On Mon, Apr 01, 2019 at 12:51:48PM +0100, Vincenzo Frascino wrote:
> diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c
> index 2d419006ad43..47ba72345739 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..7a2cd2f8e13a 100644
> --- a/arch/arm64/kernel/vdso/gettimeofday.S
> +++ b/arch/arm64/kernel/vdso/gettimeofday.S
> @@ -296,32 +296,35 @@ 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 */
> +	seqcnt_acquire
> +	syscall_check fail=5f
> +	ldr	x2, [vdso_data, #CLOCK_REALTIME_RES]
> +	seqcnt_check fail=1b
> +	b	3f
> +2:

We talked briefly but I'm still confused why we need the fallback to the
syscall here if archdata.vdso_direct is false. Is it because if the
timer driver code sets vdso_direct to false, we don't don't support
highres timers? If my understanding is correct, you may want to move the
hrtimer_res setting in update_vsyscall() to the !use_syscall block.

-- 
Catalin

Re: [PATCH 1/5] arm64: Fix vDSO clock_getres()

[Catalin Marinas]

On Mon, Apr 01, 2019 at 12:51:48PM +0100, Vincenzo Frascino wrote:
> diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c
> index 2d419006ad43..47ba72345739 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..7a2cd2f8e13a 100644
> --- a/arch/arm64/kernel/vdso/gettimeofday.S
> +++ b/arch/arm64/kernel/vdso/gettimeofday.S
> @@ -296,32 +296,35 @@ 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 */
> +	seqcnt_acquire
> +	syscall_check fail=5f
> +	ldr	x2, [vdso_data, #CLOCK_REALTIME_RES]
> +	seqcnt_check fail=1b
> +	b	3f
> +2:

We talked briefly but I'm still confused why we need the fallback to the
syscall here if archdata.vdso_direct is false. Is it because if the
timer driver code sets vdso_direct to false, we don't don't support
highres timers? If my understanding is correct, you may want to move the
hrtimer_res setting in update_vsyscall() to the !use_syscall block.

-- 
Catalin

Re: [PATCH 1/5] arm64: Fix vDSO clock_getres()

[Vincenzo Frascino]

Hi Catalin,

On 15/04/2019 18:35, Catalin Marinas wrote:
> On Mon, Apr 01, 2019 at 12:51:48PM +0100, Vincenzo Frascino wrote:
>> diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c
>> index 2d419006ad43..47ba72345739 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..7a2cd2f8e13a 100644
>> --- a/arch/arm64/kernel/vdso/gettimeofday.S
>> +++ b/arch/arm64/kernel/vdso/gettimeofday.S
>> @@ -296,32 +296,35 @@ 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 */
>> +	seqcnt_acquire
>> +	syscall_check fail=5f
>> +	ldr	x2, [vdso_data, #CLOCK_REALTIME_RES]
>> +	seqcnt_check fail=1b
>> +	b	3f
>> +2:
> 
> We talked briefly but I'm still confused why we need the fallback to the
> syscall here if archdata.vdso_direct is false. Is it because if the
> timer driver code sets vdso_direct to false, we don't don't support
> highres timers? If my understanding is correct, you may want to move the
> hrtimer_res setting in update_vsyscall() to the !use_syscall block.
> 

Ok, so let me try to provide more details on what I mentioned yesterday:
- clock_getres syscall follows the rules of what defined in posix-timers.c
- based on the clock_id that, for this purpose, can be separated in coarse and
non-coarse calls either posix_get_coarse_res() or posix_get_hrtimer_res().
- if clock id is set to a coarse clock and posix_get_coarse_res() is invoked,
happens what follows:

static int posix_get_coarse_res(const clockid_t which_clock,
				struct timespec64 *tp)
{
	*tp = ktime_to_timespec64(KTIME_LOW_RES);
	return 0;
}

Note that since CONFIG_1HZ seems not supported (jiffies.h) by the kernel in this
case we do not need rounding in our vDSO implementation.

- if clock id is set to non-coarse and posix_get_hrtimer_res() is invoked,
happens the following:

static int posix_get_hrtimer_res(clockid_t which_clock, struct timespec64 *tp)
{
	tp->tv_sec = 0;
	tp->tv_nsec = hrtimer_resolution;
	return 0;
}

hrtimer_resolution can be high res or low res depending on the call of
hrtimer_switch_to_hres(). For us the only way to preserve the correct value is
to keep it in the vdso data page.

- The assembly code mimics exactly the same behaviour detailed above, with one
difference: the one related to the use_syscall parameter which is specific to arm64.
The use_syscall parameter is set by arm_arch_timer and consumed by
update_vsyscall(). To mirror what update_vsyscall does in update_vsyscall() I
check "syscall_check fail=5f" in clock_getres vdso function.

Said that, even if functionally it is the same thing, I think it is logically
more correct to have hrtimer_res setting inside the !use_syscall block, hence I
am going to change it in the next iteration.

Please let me know your thoughts.

-- 
Regards,
Vincenzo

Re: [PATCH 1/5] arm64: Fix vDSO clock_getres()

[Vincenzo Frascino]

Hi Catalin,

On 15/04/2019 18:35, Catalin Marinas wrote:
> On Mon, Apr 01, 2019 at 12:51:48PM +0100, Vincenzo Frascino wrote:
>> diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c
>> index 2d419006ad43..47ba72345739 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..7a2cd2f8e13a 100644
>> --- a/arch/arm64/kernel/vdso/gettimeofday.S
>> +++ b/arch/arm64/kernel/vdso/gettimeofday.S
>> @@ -296,32 +296,35 @@ 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 */
>> +	seqcnt_acquire
>> +	syscall_check fail=5f
>> +	ldr	x2, [vdso_data, #CLOCK_REALTIME_RES]
>> +	seqcnt_check fail=1b
>> +	b	3f
>> +2:
> 
> We talked briefly but I'm still confused why we need the fallback to the
> syscall here if archdata.vdso_direct is false. Is it because if the
> timer driver code sets vdso_direct to false, we don't don't support
> highres timers? If my understanding is correct, you may want to move the
> hrtimer_res setting in update_vsyscall() to the !use_syscall block.
> 

Ok, so let me try to provide more details on what I mentioned yesterday:
- clock_getres syscall follows the rules of what defined in posix-timers.c
- based on the clock_id that, for this purpose, can be separated in coarse and
non-coarse calls either posix_get_coarse_res() or posix_get_hrtimer_res().
- if clock id is set to a coarse clock and posix_get_coarse_res() is invoked,
happens what follows:

static int posix_get_coarse_res(const clockid_t which_clock,
				struct timespec64 *tp)
{
	*tp = ktime_to_timespec64(KTIME_LOW_RES);
	return 0;
}

Note that since CONFIG_1HZ seems not supported (jiffies.h) by the kernel in this
case we do not need rounding in our vDSO implementation.

- if clock id is set to non-coarse and posix_get_hrtimer_res() is invoked,
happens the following:

static int posix_get_hrtimer_res(clockid_t which_clock, struct timespec64 *tp)
{
	tp->tv_sec = 0;
	tp->tv_nsec = hrtimer_resolution;
	return 0;
}

hrtimer_resolution can be high res or low res depending on the call of
hrtimer_switch_to_hres(). For us the only way to preserve the correct value is
to keep it in the vdso data page.

- The assembly code mimics exactly the same behaviour detailed above, with one
difference: the one related to the use_syscall parameter which is specific to arm64.
The use_syscall parameter is set by arm_arch_timer and consumed by
update_vsyscall(). To mirror what update_vsyscall does in update_vsyscall() I
check "syscall_check fail=5f" in clock_getres vdso function.

Said that, even if functionally it is the same thing, I think it is logically
more correct to have hrtimer_res setting inside the !use_syscall block, hence I
am going to change it in the next iteration.

Please let me know your thoughts.

-- 
Regards,
Vincenzo

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Re: [PATCH 1/5] arm64: Fix vDSO clock_getres()

[Vincenzo Frascino]

Hi Catalin,

On 15/04/2019 18:35, Catalin Marinas wrote:
> On Mon, Apr 01, 2019 at 12:51:48PM +0100, Vincenzo Frascino wrote:
>> diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c
>> index 2d419006ad43..47ba72345739 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..7a2cd2f8e13a 100644
>> --- a/arch/arm64/kernel/vdso/gettimeofday.S
>> +++ b/arch/arm64/kernel/vdso/gettimeofday.S
>> @@ -296,32 +296,35 @@ 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 */
>> +	seqcnt_acquire
>> +	syscall_check fail=5f
>> +	ldr	x2, [vdso_data, #CLOCK_REALTIME_RES]
>> +	seqcnt_check fail=1b
>> +	b	3f
>> +2:
> 
> We talked briefly but I'm still confused why we need the fallback to the
> syscall here if archdata.vdso_direct is false. Is it because if the
> timer driver code sets vdso_direct to false, we don't don't support
> highres timers? If my understanding is correct, you may want to move the
> hrtimer_res setting in update_vsyscall() to the !use_syscall block.
> 

Ok, so let me try to provide more details on what I mentioned yesterday:
- clock_getres syscall follows the rules of what defined in posix-timers.c
- based on the clock_id that, for this purpose, can be separated in coarse and
non-coarse calls either posix_get_coarse_res() or posix_get_hrtimer_res().
- if clock id is set to a coarse clock and posix_get_coarse_res() is invoked,
happens what follows:

static int posix_get_coarse_res(const clockid_t which_clock,
				struct timespec64 *tp)
{
	*tp = ktime_to_timespec64(KTIME_LOW_RES);
	return 0;
}

Note that since CONFIG_1HZ seems not supported (jiffies.h) by the kernel in this
case we do not need rounding in our vDSO implementation.

- if clock id is set to non-coarse and posix_get_hrtimer_res() is invoked,
happens the following:

static int posix_get_hrtimer_res(clockid_t which_clock, struct timespec64 *tp)
{
	tp->tv_sec = 0;
	tp->tv_nsec = hrtimer_resolution;
	return 0;
}

hrtimer_resolution can be high res or low res depending on the call of
hrtimer_switch_to_hres(). For us the only way to preserve the correct value is
to keep it in the vdso data page.

- The assembly code mimics exactly the same behaviour detailed above, with one
difference: the one related to the use_syscall parameter which is specific to arm64.
The use_syscall parameter is set by arm_arch_timer and consumed by
update_vsyscall(). To mirror what update_vsyscall does in update_vsyscall() I
check "syscall_check fail=5f" in clock_getres vdso function.

Said that, even if functionally it is the same thing, I think it is logically
more correct to have hrtimer_res setting inside the !use_syscall block, hence I
am going to change it in the next iteration.

Please let me know your thoughts.

-- 
Regards,
Vincenzo

Re: [PATCH 1/5] arm64: Fix vDSO clock_getres()

[Vincenzo Frascino]

Hi Catalin,

On 15/04/2019 18:35, Catalin Marinas wrote:
> On Mon, Apr 01, 2019 at 12:51:48PM +0100, Vincenzo Frascino wrote:
>> diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c
>> index 2d419006ad43..47ba72345739 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..7a2cd2f8e13a 100644
>> --- a/arch/arm64/kernel/vdso/gettimeofday.S
>> +++ b/arch/arm64/kernel/vdso/gettimeofday.S
>> @@ -296,32 +296,35 @@ 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 */
>> +	seqcnt_acquire
>> +	syscall_check fail=5f
>> +	ldr	x2, [vdso_data, #CLOCK_REALTIME_RES]
>> +	seqcnt_check fail=1b
>> +	b	3f
>> +2:
> 
> We talked briefly but I'm still confused why we need the fallback to the
> syscall here if archdata.vdso_direct is false. Is it because if the
> timer driver code sets vdso_direct to false, we don't don't support
> highres timers? If my understanding is correct, you may want to move the
> hrtimer_res setting in update_vsyscall() to the !use_syscall block.
> 

Ok, so let me try to provide more details on what I mentioned yesterday:
- clock_getres syscall follows the rules of what defined in posix-timers.c
- based on the clock_id that, for this purpose, can be separated in coarse and
non-coarse calls either posix_get_coarse_res() or posix_get_hrtimer_res().
- if clock id is set to a coarse clock and posix_get_coarse_res() is invoked,
happens what follows:

static int posix_get_coarse_res(const clockid_t which_clock,
				struct timespec64 *tp)
{
	*tp = ktime_to_timespec64(KTIME_LOW_RES);
	return 0;
}

Note that since CONFIG_1HZ seems not supported (jiffies.h) by the kernel in this
case we do not need rounding in our vDSO implementation.

- if clock id is set to non-coarse and posix_get_hrtimer_res() is invoked,
happens the following:

static int posix_get_hrtimer_res(clockid_t which_clock, struct timespec64 *tp)
{
	tp->tv_sec = 0;
	tp->tv_nsec = hrtimer_resolution;
	return 0;
}

hrtimer_resolution can be high res or low res depending on the call of
hrtimer_switch_to_hres(). For us the only way to preserve the correct value is
to keep it in the vdso data page.

- The assembly code mimics exactly the same behaviour detailed above, with one
difference: the one related to the use_syscall parameter which is specific to arm64.
The use_syscall parameter is set by arm_arch_timer and consumed by
update_vsyscall(). To mirror what update_vsyscall does in update_vsyscall() I
check "syscall_check fail=5f" in clock_getres vdso function.

Said that, even if functionally it is the same thing, I think it is logically
more correct to have hrtimer_res setting inside the !use_syscall block, hence I
am going to change it in the next iteration.

Please let me know your thoughts.

-- 
Regards,
Vincenzo

Re: [PATCH 1/5] arm64: Fix vDSO clock_getres()

[Will Deacon]

On Tue, Apr 16, 2019 at 01:42:58PM +0100, Vincenzo Frascino wrote:
> On 15/04/2019 18:35, Catalin Marinas wrote:
> > On Mon, Apr 01, 2019 at 12:51:48PM +0100, Vincenzo Frascino wrote:
> >> +1:	/* Get hrtimer_res */
> >> +	seqcnt_acquire
> >> +	syscall_check fail=5f
> >> +	ldr	x2, [vdso_data, #CLOCK_REALTIME_RES]
> >> +	seqcnt_check fail=1b
> >> +	b	3f
> >> +2:
> > 
> > We talked briefly but I'm still confused why we need the fallback to the
> > syscall here if archdata.vdso_direct is false. Is it because if the
> > timer driver code sets vdso_direct to false, we don't don't support
> > highres timers? If my understanding is correct, you may want to move the
> > hrtimer_res setting in update_vsyscall() to the !use_syscall block.
> > 
> 
> Ok, so let me try to provide more details on what I mentioned yesterday:
> - clock_getres syscall follows the rules of what defined in posix-timers.c
> - based on the clock_id that, for this purpose, can be separated in coarse and
> non-coarse calls either posix_get_coarse_res() or posix_get_hrtimer_res().
> - if clock id is set to a coarse clock and posix_get_coarse_res() is invoked,
> happens what follows:
> 
> static int posix_get_coarse_res(const clockid_t which_clock,
> 				struct timespec64 *tp)
> {
> 	*tp = ktime_to_timespec64(KTIME_LOW_RES);
> 	return 0;
> }
> 
> Note that since CONFIG_1HZ seems not supported (jiffies.h) by the kernel in this
> case we do not need rounding in our vDSO implementation.
> 
> - if clock id is set to non-coarse and posix_get_hrtimer_res() is invoked,
> happens the following:
> 
> static int posix_get_hrtimer_res(clockid_t which_clock, struct timespec64 *tp)
> {
> 	tp->tv_sec = 0;
> 	tp->tv_nsec = hrtimer_resolution;
> 	return 0;
> }
> 
> hrtimer_resolution can be high res or low res depending on the call of
> hrtimer_switch_to_hres(). For us the only way to preserve the correct value is
> to keep it in the vdso data page.
> 
> - The assembly code mimics exactly the same behaviour detailed above, with one
> difference: the one related to the use_syscall parameter which is specific to arm64.
> The use_syscall parameter is set by arm_arch_timer and consumed by
> update_vsyscall(). To mirror what update_vsyscall does in update_vsyscall() I
> check "syscall_check fail=5f" in clock_getres vdso function.
> 
> Said that, even if functionally it is the same thing, I think it is logically
> more correct to have hrtimer_res setting inside the !use_syscall block, hence I
> am going to change it in the next iteration.
> 
> Please let me know your thoughts.

I think you can ignore the syscall_check, just like we seem to do for
CLOCK_REALTIME_COARSE and CLOCK_MONOTONIC_COARSE in clock_gettime().

Will

Re: [PATCH 1/5] arm64: Fix vDSO clock_getres()

[Will Deacon]

On Tue, Apr 16, 2019 at 01:42:58PM +0100, Vincenzo Frascino wrote:
> On 15/04/2019 18:35, Catalin Marinas wrote:
> > On Mon, Apr 01, 2019 at 12:51:48PM +0100, Vincenzo Frascino wrote:
> >> +1:	/* Get hrtimer_res */
> >> +	seqcnt_acquire
> >> +	syscall_check fail=5f
> >> +	ldr	x2, [vdso_data, #CLOCK_REALTIME_RES]
> >> +	seqcnt_check fail=1b
> >> +	b	3f
> >> +2:
> > 
> > We talked briefly but I'm still confused why we need the fallback to the
> > syscall here if archdata.vdso_direct is false. Is it because if the
> > timer driver code sets vdso_direct to false, we don't don't support
> > highres timers? If my understanding is correct, you may want to move the
> > hrtimer_res setting in update_vsyscall() to the !use_syscall block.
> > 
> 
> Ok, so let me try to provide more details on what I mentioned yesterday:
> - clock_getres syscall follows the rules of what defined in posix-timers.c
> - based on the clock_id that, for this purpose, can be separated in coarse and
> non-coarse calls either posix_get_coarse_res() or posix_get_hrtimer_res().
> - if clock id is set to a coarse clock and posix_get_coarse_res() is invoked,
> happens what follows:
> 
> static int posix_get_coarse_res(const clockid_t which_clock,
> 				struct timespec64 *tp)
> {
> 	*tp = ktime_to_timespec64(KTIME_LOW_RES);
> 	return 0;
> }
> 
> Note that since CONFIG_1HZ seems not supported (jiffies.h) by the kernel in this
> case we do not need rounding in our vDSO implementation.
> 
> - if clock id is set to non-coarse and posix_get_hrtimer_res() is invoked,
> happens the following:
> 
> static int posix_get_hrtimer_res(clockid_t which_clock, struct timespec64 *tp)
> {
> 	tp->tv_sec = 0;
> 	tp->tv_nsec = hrtimer_resolution;
> 	return 0;
> }
> 
> hrtimer_resolution can be high res or low res depending on the call of
> hrtimer_switch_to_hres(). For us the only way to preserve the correct value is
> to keep it in the vdso data page.
> 
> - The assembly code mimics exactly the same behaviour detailed above, with one
> difference: the one related to the use_syscall parameter which is specific to arm64.
> The use_syscall parameter is set by arm_arch_timer and consumed by
> update_vsyscall(). To mirror what update_vsyscall does in update_vsyscall() I
> check "syscall_check fail=5f" in clock_getres vdso function.
> 
> Said that, even if functionally it is the same thing, I think it is logically
> more correct to have hrtimer_res setting inside the !use_syscall block, hence I
> am going to change it in the next iteration.
> 
> Please let me know your thoughts.

I think you can ignore the syscall_check, just like we seem to do for
CLOCK_REALTIME_COARSE and CLOCK_MONOTONIC_COARSE in clock_gettime().

Will

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Re: [PATCH 1/5] arm64: Fix vDSO clock_getres()

[Will Deacon]

On Tue, Apr 16, 2019 at 01:42:58PM +0100, Vincenzo Frascino wrote:
> On 15/04/2019 18:35, Catalin Marinas wrote:
> > On Mon, Apr 01, 2019 at 12:51:48PM +0100, Vincenzo Frascino wrote:
> >> +1:	/* Get hrtimer_res */
> >> +	seqcnt_acquire
> >> +	syscall_check fail=5f
> >> +	ldr	x2, [vdso_data, #CLOCK_REALTIME_RES]
> >> +	seqcnt_check fail=1b
> >> +	b	3f
> >> +2:
> > 
> > We talked briefly but I'm still confused why we need the fallback to the
> > syscall here if archdata.vdso_direct is false. Is it because if the
> > timer driver code sets vdso_direct to false, we don't don't support
> > highres timers? If my understanding is correct, you may want to move the
> > hrtimer_res setting in update_vsyscall() to the !use_syscall block.
> > 
> 
> Ok, so let me try to provide more details on what I mentioned yesterday:
> - clock_getres syscall follows the rules of what defined in posix-timers.c
> - based on the clock_id that, for this purpose, can be separated in coarse and
> non-coarse calls either posix_get_coarse_res() or posix_get_hrtimer_res().
> - if clock id is set to a coarse clock and posix_get_coarse_res() is invoked,
> happens what follows:
> 
> static int posix_get_coarse_res(const clockid_t which_clock,
> 				struct timespec64 *tp)
> {
> 	*tp = ktime_to_timespec64(KTIME_LOW_RES);
> 	return 0;
> }
> 
> Note that since CONFIG_1HZ seems not supported (jiffies.h) by the kernel in this
> case we do not need rounding in our vDSO implementation.
> 
> - if clock id is set to non-coarse and posix_get_hrtimer_res() is invoked,
> happens the following:
> 
> static int posix_get_hrtimer_res(clockid_t which_clock, struct timespec64 *tp)
> {
> 	tp->tv_sec = 0;
> 	tp->tv_nsec = hrtimer_resolution;
> 	return 0;
> }
> 
> hrtimer_resolution can be high res or low res depending on the call of
> hrtimer_switch_to_hres(). For us the only way to preserve the correct value is
> to keep it in the vdso data page.
> 
> - The assembly code mimics exactly the same behaviour detailed above, with one
> difference: the one related to the use_syscall parameter which is specific to arm64.
> The use_syscall parameter is set by arm_arch_timer and consumed by
> update_vsyscall(). To mirror what update_vsyscall does in update_vsyscall() I
> check "syscall_check fail=5f" in clock_getres vdso function.
> 
> Said that, even if functionally it is the same thing, I think it is logically
> more correct to have hrtimer_res setting inside the !use_syscall block, hence I
> am going to change it in the next iteration.
> 
> Please let me know your thoughts.

I think you can ignore the syscall_check, just like we seem to do for
CLOCK_REALTIME_COARSE and CLOCK_MONOTONIC_COARSE in clock_gettime().

Will

[PATCH 2/5] powerpc: Fix vDSO clock_getres()

[Vincenzo Frascino]

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.

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>
---
 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 | 22 +++++++++++++++-------
 arch/powerpc/kernel/vdso64/gettimeofday.S | 22 +++++++++++++++-------
 5 files changed, 34 insertions(+), 15 deletions(-)

diff --git a/arch/powerpc/include/asm/vdso_datapage.h b/arch/powerpc/include/asm/vdso_datapage.h
index 1afe90ade595..4ae43fc77fe9 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;
 	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_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 86a61e5f8285..52e4b98a8492 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -383,6 +383,7 @@ 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);
@@ -413,7 +414,6 @@ 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 bc0503ef9c9c..62c04a6746d8 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -955,6 +955,7 @@ 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 1e0bc5955a40..b21630079496 100644
--- a/arch/powerpc/kernel/vdso32/gettimeofday.S
+++ b/arch/powerpc/kernel/vdso32/gettimeofday.S
@@ -160,14 +160,21 @@ V_FUNCTION_BEGIN(__kernel_clock_getres)
 	cror	cr0*4+eq,cr0*4+eq,cr1*4+eq
 	bne	cr0,99f
 
-	li	r3,0
-	cmpli	cr0,r4,0
+	mflr	r12
+  .cfi_register lr,r12
+	mr	r11,r4
+	bl	__get_datapage@local
+	lwz	r5,CLOCK_REALTIME_RES(r3)
+	li	r4,0
+	cmplwi	r11,0		/* check if res is NULL */
+	beq	1f
+
+	stw	r4,TSPC32_TV_SEC(r11)
+	stw	r5,TSPC32_TV_NSEC(r11)
+
+1:	mtlr	r12
 	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)
+	li	r3,0
 	blr
 
 	/*
@@ -175,6 +182,7 @@ V_FUNCTION_BEGIN(__kernel_clock_getres)
 	 */
 99:
 	li	r0,__NR_clock_getres
+  .cfi_restore lr
 	sc
 	blr
   .cfi_endproc
diff --git a/arch/powerpc/kernel/vdso64/gettimeofday.S b/arch/powerpc/kernel/vdso64/gettimeofday.S
index a4ed9edfd5f0..a7e49bddd475 100644
--- a/arch/powerpc/kernel/vdso64/gettimeofday.S
+++ b/arch/powerpc/kernel/vdso64/gettimeofday.S
@@ -190,14 +190,21 @@ V_FUNCTION_BEGIN(__kernel_clock_getres)
 	cror	cr0*4+eq,cr0*4+eq,cr1*4+eq
 	bne	cr0,99f
 
-	li	r3,0
-	cmpldi	cr0,r4,0
+	mflr	r12
+  .cfi_register lr,r12
+	mr	r11, r4
+	bl	V_LOCAL_FUNC(__get_datapage)
+	lwz	r5,CLOCK_REALTIME_RES(r3)
+	li	r4,0
+	cmpldi	r11,0		/* check if res is NULL */
+	beq	1f
+
+	std	r4,TSPC64_TV_SEC(r11)
+	std	r5,TSPC64_TV_NSEC(r11)
+
+1:	mtlr	r12
 	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)
+	li	r3,0
 	blr
 
 	/*
@@ -205,6 +212,7 @@ V_FUNCTION_BEGIN(__kernel_clock_getres)
 	 */
 99:
 	li	r0,__NR_clock_getres
+  .cfi_restore lr
 	sc
 	blr
   .cfi_endproc
-- 
2.21.0

[PATCH 2/5] powerpc: Fix vDSO clock_getres()

[Vincenzo Frascino]

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.

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>
---
 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 | 22 +++++++++++++++-------
 arch/powerpc/kernel/vdso64/gettimeofday.S | 22 +++++++++++++++-------
 5 files changed, 34 insertions(+), 15 deletions(-)

diff --git a/arch/powerpc/include/asm/vdso_datapage.h b/arch/powerpc/include/asm/vdso_datapage.h
index 1afe90ade595..4ae43fc77fe9 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;
 	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_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 86a61e5f8285..52e4b98a8492 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -383,6 +383,7 @@ 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);
@@ -413,7 +414,6 @@ 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 bc0503ef9c9c..62c04a6746d8 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -955,6 +955,7 @@ 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 1e0bc5955a40..b21630079496 100644
--- a/arch/powerpc/kernel/vdso32/gettimeofday.S
+++ b/arch/powerpc/kernel/vdso32/gettimeofday.S
@@ -160,14 +160,21 @@ V_FUNCTION_BEGIN(__kernel_clock_getres)
 	cror	cr0*4+eq,cr0*4+eq,cr1*4+eq
 	bne	cr0,99f
 
-	li	r3,0
-	cmpli	cr0,r4,0
+	mflr	r12
+  .cfi_register lr,r12
+	mr	r11,r4
+	bl	__get_datapage@local
+	lwz	r5,CLOCK_REALTIME_RES(r3)
+	li	r4,0
+	cmplwi	r11,0		/* check if res is NULL */
+	beq	1f
+
+	stw	r4,TSPC32_TV_SEC(r11)
+	stw	r5,TSPC32_TV_NSEC(r11)
+
+1:	mtlr	r12
 	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)
+	li	r3,0
 	blr
 
 	/*
@@ -175,6 +182,7 @@ V_FUNCTION_BEGIN(__kernel_clock_getres)
 	 */
 99:
 	li	r0,__NR_clock_getres
+  .cfi_restore lr
 	sc
 	blr
   .cfi_endproc
diff --git a/arch/powerpc/kernel/vdso64/gettimeofday.S b/arch/powerpc/kernel/vdso64/gettimeofday.S
index a4ed9edfd5f0..a7e49bddd475 100644
--- a/arch/powerpc/kernel/vdso64/gettimeofday.S
+++ b/arch/powerpc/kernel/vdso64/gettimeofday.S
@@ -190,14 +190,21 @@ V_FUNCTION_BEGIN(__kernel_clock_getres)
 	cror	cr0*4+eq,cr0*4+eq,cr1*4+eq
 	bne	cr0,99f
 
-	li	r3,0
-	cmpldi	cr0,r4,0
+	mflr	r12
+  .cfi_register lr,r12
+	mr	r11, r4
+	bl	V_LOCAL_FUNC(__get_datapage)
+	lwz	r5,CLOCK_REALTIME_RES(r3)
+	li	r4,0
+	cmpldi	r11,0		/* check if res is NULL */
+	beq	1f
+
+	std	r4,TSPC64_TV_SEC(r11)
+	std	r5,TSPC64_TV_NSEC(r11)
+
+1:	mtlr	r12
 	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)
+	li	r3,0
 	blr
 
 	/*
@@ -205,6 +212,7 @@ V_FUNCTION_BEGIN(__kernel_clock_getres)
 	 */
 99:
 	li	r0,__NR_clock_getres
+  .cfi_restore lr
 	sc
 	blr
   .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

[PATCH 2/5] powerpc: Fix vDSO clock_getres()

[Vincenzo Frascino]

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.

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>
---
 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 | 22 +++++++++++++++-------
 arch/powerpc/kernel/vdso64/gettimeofday.S | 22 +++++++++++++++-------
 5 files changed, 34 insertions(+), 15 deletions(-)

diff --git a/arch/powerpc/include/asm/vdso_datapage.h b/arch/powerpc/include/asm/vdso_datapage.h
index 1afe90ade595..4ae43fc77fe9 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;
 	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_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 86a61e5f8285..52e4b98a8492 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -383,6 +383,7 @@ 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);
@@ -413,7 +414,6 @@ 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 bc0503ef9c9c..62c04a6746d8 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -955,6 +955,7 @@ 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 1e0bc5955a40..b21630079496 100644
--- a/arch/powerpc/kernel/vdso32/gettimeofday.S
+++ b/arch/powerpc/kernel/vdso32/gettimeofday.S
@@ -160,14 +160,21 @@ V_FUNCTION_BEGIN(__kernel_clock_getres)
 	cror	cr0*4+eq,cr0*4+eq,cr1*4+eq
 	bne	cr0,99f
 
-	li	r3,0
-	cmpli	cr0,r4,0
+	mflr	r12
+  .cfi_register lr,r12
+	mr	r11,r4
+	bl	__get_datapage@local
+	lwz	r5,CLOCK_REALTIME_RES(r3)
+	li	r4,0
+	cmplwi	r11,0		/* check if res is NULL */
+	beq	1f
+
+	stw	r4,TSPC32_TV_SEC(r11)
+	stw	r5,TSPC32_TV_NSEC(r11)
+
+1:	mtlr	r12
 	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)
+	li	r3,0
 	blr
 
 	/*
@@ -175,6 +182,7 @@ V_FUNCTION_BEGIN(__kernel_clock_getres)
 	 */
 99:
 	li	r0,__NR_clock_getres
+  .cfi_restore lr
 	sc
 	blr
   .cfi_endproc
diff --git a/arch/powerpc/kernel/vdso64/gettimeofday.S b/arch/powerpc/kernel/vdso64/gettimeofday.S
index a4ed9edfd5f0..a7e49bddd475 100644
--- a/arch/powerpc/kernel/vdso64/gettimeofday.S
+++ b/arch/powerpc/kernel/vdso64/gettimeofday.S
@@ -190,14 +190,21 @@ V_FUNCTION_BEGIN(__kernel_clock_getres)
 	cror	cr0*4+eq,cr0*4+eq,cr1*4+eq
 	bne	cr0,99f
 
-	li	r3,0
-	cmpldi	cr0,r4,0
+	mflr	r12
+  .cfi_register lr,r12
+	mr	r11, r4
+	bl	V_LOCAL_FUNC(__get_datapage)
+	lwz	r5,CLOCK_REALTIME_RES(r3)
+	li	r4,0
+	cmpldi	r11,0		/* check if res is NULL */
+	beq	1f
+
+	std	r4,TSPC64_TV_SEC(r11)
+	std	r5,TSPC64_TV_NSEC(r11)
+
+1:	mtlr	r12
 	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)
+	li	r3,0
 	blr
 
 	/*
@@ -205,6 +212,7 @@ V_FUNCTION_BEGIN(__kernel_clock_getres)
 	 */
 99:
 	li	r0,__NR_clock_getres
+  .cfi_restore lr
 	sc
 	blr
   .cfi_endproc
-- 
2.21.0

[PATCH 2/5] powerpc: Fix vDSO clock_getres()

[Vincenzo Frascino]

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.

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>
---
 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 | 22 +++++++++++++++-------
 arch/powerpc/kernel/vdso64/gettimeofday.S | 22 +++++++++++++++-------
 5 files changed, 34 insertions(+), 15 deletions(-)

diff --git a/arch/powerpc/include/asm/vdso_datapage.h b/arch/powerpc/include/asm/vdso_datapage.h
index 1afe90ade595..4ae43fc77fe9 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;
 	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_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 86a61e5f8285..52e4b98a8492 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -383,6 +383,7 @@ 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);
@@ -413,7 +414,6 @@ 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 bc0503ef9c9c..62c04a6746d8 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -955,6 +955,7 @@ 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 1e0bc5955a40..b21630079496 100644
--- a/arch/powerpc/kernel/vdso32/gettimeofday.S
+++ b/arch/powerpc/kernel/vdso32/gettimeofday.S
@@ -160,14 +160,21 @@ V_FUNCTION_BEGIN(__kernel_clock_getres)
 	cror	cr0*4+eq,cr0*4+eq,cr1*4+eq
 	bne	cr0,99f
 
-	li	r3,0
-	cmpli	cr0,r4,0
+	mflr	r12
+  .cfi_register lr,r12
+	mr	r11,r4
+	bl	__get_datapage@local
+	lwz	r5,CLOCK_REALTIME_RES(r3)
+	li	r4,0
+	cmplwi	r11,0		/* check if res is NULL */
+	beq	1f
+
+	stw	r4,TSPC32_TV_SEC(r11)
+	stw	r5,TSPC32_TV_NSEC(r11)
+
+1:	mtlr	r12
 	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)
+	li	r3,0
 	blr
 
 	/*
@@ -175,6 +182,7 @@ V_FUNCTION_BEGIN(__kernel_clock_getres)
 	 */
 99:
 	li	r0,__NR_clock_getres
+  .cfi_restore lr
 	sc
 	blr
   .cfi_endproc
diff --git a/arch/powerpc/kernel/vdso64/gettimeofday.S b/arch/powerpc/kernel/vdso64/gettimeofday.S
index a4ed9edfd5f0..a7e49bddd475 100644
--- a/arch/powerpc/kernel/vdso64/gettimeofday.S
+++ b/arch/powerpc/kernel/vdso64/gettimeofday.S
@@ -190,14 +190,21 @@ V_FUNCTION_BEGIN(__kernel_clock_getres)
 	cror	cr0*4+eq,cr0*4+eq,cr1*4+eq
 	bne	cr0,99f
 
-	li	r3,0
-	cmpldi	cr0,r4,0
+	mflr	r12
+  .cfi_register lr,r12
+	mr	r11, r4
+	bl	V_LOCAL_FUNC(__get_datapage)
+	lwz	r5,CLOCK_REALTIME_RES(r3)
+	li	r4,0
+	cmpldi	r11,0		/* check if res is NULL */
+	beq	1f
+
+	std	r4,TSPC64_TV_SEC(r11)
+	std	r5,TSPC64_TV_NSEC(r11)
+
+1:	mtlr	r12
 	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)
+	li	r3,0
 	blr
 
 	/*
@@ -205,6 +212,7 @@ V_FUNCTION_BEGIN(__kernel_clock_getres)
 	 */
 99:
 	li	r0,__NR_clock_getres
+  .cfi_restore lr
 	sc
 	blr
   .cfi_endproc
-- 
2.21.0

Re: [PATCH 2/5] powerpc: Fix vDSO clock_getres()

[Christophe Leroy]

On 04/01/2019 11:51 AM, Vincenzo Frascino wrote:
> 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.
> 
> 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>
> ---
>   arch/powerpc/include/asm/vdso_datapage.h  |  2 ++

Conflicts with commit b5b4453e7912 ("powerpc/vdso64: Fix CLOCK_MONOTONIC 
inconsistencies across Y2038")

Christophe



>   arch/powerpc/kernel/asm-offsets.c         |  2 +-
>   arch/powerpc/kernel/time.c                |  1 +
>   arch/powerpc/kernel/vdso32/gettimeofday.S | 22 +++++++++++++++-------
>   arch/powerpc/kernel/vdso64/gettimeofday.S | 22 +++++++++++++++-------
>   5 files changed, 34 insertions(+), 15 deletions(-)
> 
> diff --git a/arch/powerpc/include/asm/vdso_datapage.h b/arch/powerpc/include/asm/vdso_datapage.h
> index 1afe90ade595..4ae43fc77fe9 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;
>   	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_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 86a61e5f8285..52e4b98a8492 100644
> --- a/arch/powerpc/kernel/asm-offsets.c
> +++ b/arch/powerpc/kernel/asm-offsets.c
> @@ -383,6 +383,7 @@ 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);
> @@ -413,7 +414,6 @@ 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 bc0503ef9c9c..62c04a6746d8 100644
> --- a/arch/powerpc/kernel/time.c
> +++ b/arch/powerpc/kernel/time.c
> @@ -955,6 +955,7 @@ 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 1e0bc5955a40..b21630079496 100644
> --- a/arch/powerpc/kernel/vdso32/gettimeofday.S
> +++ b/arch/powerpc/kernel/vdso32/gettimeofday.S
> @@ -160,14 +160,21 @@ V_FUNCTION_BEGIN(__kernel_clock_getres)
>   	cror	cr0*4+eq,cr0*4+eq,cr1*4+eq
>   	bne	cr0,99f
>   
> -	li	r3,0
> -	cmpli	cr0,r4,0
> +	mflr	r12
> +  .cfi_register lr,r12
> +	mr	r11,r4
> +	bl	__get_datapage@local
> +	lwz	r5,CLOCK_REALTIME_RES(r3)
> +	li	r4,0
> +	cmplwi	r11,0		/* check if res is NULL */
> +	beq	1f
> +
> +	stw	r4,TSPC32_TV_SEC(r11)
> +	stw	r5,TSPC32_TV_NSEC(r11)
> +
> +1:	mtlr	r12
>   	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)
> +	li	r3,0
>   	blr
>   
>   	/*
> @@ -175,6 +182,7 @@ V_FUNCTION_BEGIN(__kernel_clock_getres)
>   	 */
>   99:
>   	li	r0,__NR_clock_getres
> +  .cfi_restore lr
>   	sc
>   	blr
>     .cfi_endproc
> diff --git a/arch/powerpc/kernel/vdso64/gettimeofday.S b/arch/powerpc/kernel/vdso64/gettimeofday.S
> index a4ed9edfd5f0..a7e49bddd475 100644
> --- a/arch/powerpc/kernel/vdso64/gettimeofday.S
> +++ b/arch/powerpc/kernel/vdso64/gettimeofday.S
> @@ -190,14 +190,21 @@ V_FUNCTION_BEGIN(__kernel_clock_getres)
>   	cror	cr0*4+eq,cr0*4+eq,cr1*4+eq
>   	bne	cr0,99f
>   
> -	li	r3,0
> -	cmpldi	cr0,r4,0
> +	mflr	r12
> +  .cfi_register lr,r12
> +	mr	r11, r4
> +	bl	V_LOCAL_FUNC(__get_datapage)
> +	lwz	r5,CLOCK_REALTIME_RES(r3)
> +	li	r4,0
> +	cmpldi	r11,0		/* check if res is NULL */
> +	beq	1f
> +
> +	std	r4,TSPC64_TV_SEC(r11)
> +	std	r5,TSPC64_TV_NSEC(r11)
> +
> +1:	mtlr	r12
>   	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)
> +	li	r3,0
>   	blr
>   
>   	/*
> @@ -205,6 +212,7 @@ V_FUNCTION_BEGIN(__kernel_clock_getres)
>   	 */
>   99:
>   	li	r0,__NR_clock_getres
> +  .cfi_restore lr
>   	sc
>   	blr
>     .cfi_endproc
> 

Re: [PATCH 2/5] powerpc: Fix vDSO clock_getres()

[Christophe Leroy]

On 04/01/2019 11:51 AM, Vincenzo Frascino wrote:
> 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.
> 
> 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>
> ---
>   arch/powerpc/include/asm/vdso_datapage.h  |  2 ++

Conflicts with commit b5b4453e7912 ("powerpc/vdso64: Fix CLOCK_MONOTONIC 
inconsistencies across Y2038")

Christophe



>   arch/powerpc/kernel/asm-offsets.c         |  2 +-
>   arch/powerpc/kernel/time.c                |  1 +
>   arch/powerpc/kernel/vdso32/gettimeofday.S | 22 +++++++++++++++-------
>   arch/powerpc/kernel/vdso64/gettimeofday.S | 22 +++++++++++++++-------
>   5 files changed, 34 insertions(+), 15 deletions(-)
> 
> diff --git a/arch/powerpc/include/asm/vdso_datapage.h b/arch/powerpc/include/asm/vdso_datapage.h
> index 1afe90ade595..4ae43fc77fe9 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;
>   	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_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 86a61e5f8285..52e4b98a8492 100644
> --- a/arch/powerpc/kernel/asm-offsets.c
> +++ b/arch/powerpc/kernel/asm-offsets.c
> @@ -383,6 +383,7 @@ 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);
> @@ -413,7 +414,6 @@ 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 bc0503ef9c9c..62c04a6746d8 100644
> --- a/arch/powerpc/kernel/time.c
> +++ b/arch/powerpc/kernel/time.c
> @@ -955,6 +955,7 @@ 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 1e0bc5955a40..b21630079496 100644
> --- a/arch/powerpc/kernel/vdso32/gettimeofday.S
> +++ b/arch/powerpc/kernel/vdso32/gettimeofday.S
> @@ -160,14 +160,21 @@ V_FUNCTION_BEGIN(__kernel_clock_getres)
>   	cror	cr0*4+eq,cr0*4+eq,cr1*4+eq
>   	bne	cr0,99f
>   
> -	li	r3,0
> -	cmpli	cr0,r4,0
> +	mflr	r12
> +  .cfi_register lr,r12
> +	mr	r11,r4
> +	bl	__get_datapage@local
> +	lwz	r5,CLOCK_REALTIME_RES(r3)
> +	li	r4,0
> +	cmplwi	r11,0		/* check if res is NULL */
> +	beq	1f
> +
> +	stw	r4,TSPC32_TV_SEC(r11)
> +	stw	r5,TSPC32_TV_NSEC(r11)
> +
> +1:	mtlr	r12
>   	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)
> +	li	r3,0
>   	blr
>   
>   	/*
> @@ -175,6 +182,7 @@ V_FUNCTION_BEGIN(__kernel_clock_getres)
>   	 */
>   99:
>   	li	r0,__NR_clock_getres
> +  .cfi_restore lr
>   	sc
>   	blr
>     .cfi_endproc
> diff --git a/arch/powerpc/kernel/vdso64/gettimeofday.S b/arch/powerpc/kernel/vdso64/gettimeofday.S
> index a4ed9edfd5f0..a7e49bddd475 100644
> --- a/arch/powerpc/kernel/vdso64/gettimeofday.S
> +++ b/arch/powerpc/kernel/vdso64/gettimeofday.S
> @@ -190,14 +190,21 @@ V_FUNCTION_BEGIN(__kernel_clock_getres)
>   	cror	cr0*4+eq,cr0*4+eq,cr1*4+eq
>   	bne	cr0,99f
>   
> -	li	r3,0
> -	cmpldi	cr0,r4,0
> +	mflr	r12
> +  .cfi_register lr,r12
> +	mr	r11, r4
> +	bl	V_LOCAL_FUNC(__get_datapage)
> +	lwz	r5,CLOCK_REALTIME_RES(r3)
> +	li	r4,0
> +	cmpldi	r11,0		/* check if res is NULL */
> +	beq	1f
> +
> +	std	r4,TSPC64_TV_SEC(r11)
> +	std	r5,TSPC64_TV_NSEC(r11)
> +
> +1:	mtlr	r12
>   	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)
> +	li	r3,0
>   	blr
>   
>   	/*
> @@ -205,6 +212,7 @@ V_FUNCTION_BEGIN(__kernel_clock_getres)
>   	 */
>   99:
>   	li	r0,__NR_clock_getres
> +  .cfi_restore lr
>   	sc
>   	blr
>     .cfi_endproc
> 

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Re: [PATCH 2/5] powerpc: Fix vDSO clock_getres()

[Vincenzo Frascino]

Hi Christophe,

thank you for your review.

On 02/04/2019 06:54, Christophe Leroy wrote:
> 
> 
> On 04/01/2019 11:51 AM, Vincenzo Frascino wrote:
>> 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.
>>
>> 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>
>> ---
>>   arch/powerpc/include/asm/vdso_datapage.h  |  2 ++
> 
> Conflicts with commit b5b4453e7912 ("powerpc/vdso64: Fix CLOCK_MONOTONIC 
> inconsistencies across Y2038")
> 

Thanks for pointing this out, I will rebase my code on top of the latest version
before reissuing v2.

...

-- 
Regards,
Vincenzo

Re: [PATCH 2/5] powerpc: Fix vDSO clock_getres()

[Vincenzo Frascino]

Hi Christophe,

thank you for your review.

On 02/04/2019 06:54, Christophe Leroy wrote:
> 
> 
> On 04/01/2019 11:51 AM, Vincenzo Frascino wrote:
>> 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.
>>
>> 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>
>> ---
>>   arch/powerpc/include/asm/vdso_datapage.h  |  2 ++
> 
> Conflicts with commit b5b4453e7912 ("powerpc/vdso64: Fix CLOCK_MONOTONIC 
> inconsistencies across Y2038")
> 

Thanks for pointing this out, I will rebase my code on top of the latest version
before reissuing v2.

...

-- 
Regards,
Vincenzo

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Re: [PATCH 2/5] powerpc: Fix vDSO clock_getres()

[Christophe Leroy]

On 04/01/2019 11:51 AM, Vincenzo Frascino wrote:
> 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.
> 
> 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>
> ---
>   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 | 22 +++++++++++++++-------
>   arch/powerpc/kernel/vdso64/gettimeofday.S | 22 +++++++++++++++-------
>   5 files changed, 34 insertions(+), 15 deletions(-)
> 

[...]

> diff --git a/arch/powerpc/kernel/vdso32/gettimeofday.S b/arch/powerpc/kernel/vdso32/gettimeofday.S
> index 1e0bc5955a40..b21630079496 100644
> --- a/arch/powerpc/kernel/vdso32/gettimeofday.S
> +++ b/arch/powerpc/kernel/vdso32/gettimeofday.S
> @@ -160,14 +160,21 @@ V_FUNCTION_BEGIN(__kernel_clock_getres)
>   	cror	cr0*4+eq,cr0*4+eq,cr1*4+eq
>   	bne	cr0,99f
>   
> -	li	r3,0
> -	cmpli	cr0,r4,0
> +	mflr	r12
> +  .cfi_register lr,r12
> +	mr	r11,r4
> +	bl	__get_datapage@local
> +	lwz	r5,CLOCK_REALTIME_RES(r3)
> +	li	r4,0
> +	cmplwi	r11,0		/* check if res is NULL */
> +	beq	1f
> +
> +	stw	r4,TSPC32_TV_SEC(r11)
> +	stw	r5,TSPC32_TV_NSEC(r11)
> +
> +1:	mtlr	r12
>   	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)
> +	li	r3,0
>   	blr

The above can be done simpler, see below

@@ -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

Christophe

>   
>   	/*
> @@ -175,6 +182,7 @@ V_FUNCTION_BEGIN(__kernel_clock_getres)
>   	 */
>   99:
>   	li	r0,__NR_clock_getres
> +  .cfi_restore lr
>   	sc
>   	blr
>     .cfi_endproc
> diff --git a/arch/powerpc/kernel/vdso64/gettimeofday.S b/arch/powerpc/kernel/vdso64/gettimeofday.S
> index a4ed9edfd5f0..a7e49bddd475 100644
> --- a/arch/powerpc/kernel/vdso64/gettimeofday.S
> +++ b/arch/powerpc/kernel/vdso64/gettimeofday.S
> @@ -190,14 +190,21 @@ V_FUNCTION_BEGIN(__kernel_clock_getres)
>   	cror	cr0*4+eq,cr0*4+eq,cr1*4+eq
>   	bne	cr0,99f
>   
> -	li	r3,0
> -	cmpldi	cr0,r4,0
> +	mflr	r12
> +  .cfi_register lr,r12
> +	mr	r11, r4
> +	bl	V_LOCAL_FUNC(__get_datapage)
> +	lwz	r5,CLOCK_REALTIME_RES(r3)
> +	li	r4,0
> +	cmpldi	r11,0		/* check if res is NULL */
> +	beq	1f
> +
> +	std	r4,TSPC64_TV_SEC(r11)
> +	std	r5,TSPC64_TV_NSEC(r11)
> +
> +1:	mtlr	r12
>   	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)
> +	li	r3,0
>   	blr

The same type of simplification applies here too.

Christophe


>   
>   	/*
> @@ -205,6 +212,7 @@ V_FUNCTION_BEGIN(__kernel_clock_getres)
>   	 */
>   99:
>   	li	r0,__NR_clock_getres
> +  .cfi_restore lr
>   	sc
>   	blr
>     .cfi_endproc
> 

Re: [PATCH 2/5] powerpc: Fix vDSO clock_getres()

[Christophe Leroy]

On 04/01/2019 11:51 AM, Vincenzo Frascino wrote:
> 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.
> 
> 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>
> ---
>   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 | 22 +++++++++++++++-------
>   arch/powerpc/kernel/vdso64/gettimeofday.S | 22 +++++++++++++++-------
>   5 files changed, 34 insertions(+), 15 deletions(-)
> 

[...]

> diff --git a/arch/powerpc/kernel/vdso32/gettimeofday.S b/arch/powerpc/kernel/vdso32/gettimeofday.S
> index 1e0bc5955a40..b21630079496 100644
> --- a/arch/powerpc/kernel/vdso32/gettimeofday.S
> +++ b/arch/powerpc/kernel/vdso32/gettimeofday.S
> @@ -160,14 +160,21 @@ V_FUNCTION_BEGIN(__kernel_clock_getres)
>   	cror	cr0*4+eq,cr0*4+eq,cr1*4+eq
>   	bne	cr0,99f
>   
> -	li	r3,0
> -	cmpli	cr0,r4,0
> +	mflr	r12
> +  .cfi_register lr,r12
> +	mr	r11,r4
> +	bl	__get_datapage@local
> +	lwz	r5,CLOCK_REALTIME_RES(r3)
> +	li	r4,0
> +	cmplwi	r11,0		/* check if res is NULL */
> +	beq	1f
> +
> +	stw	r4,TSPC32_TV_SEC(r11)
> +	stw	r5,TSPC32_TV_NSEC(r11)
> +
> +1:	mtlr	r12
>   	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)
> +	li	r3,0
>   	blr

The above can be done simpler, see below

@@ -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

Christophe

>   
>   	/*
> @@ -175,6 +182,7 @@ V_FUNCTION_BEGIN(__kernel_clock_getres)
>   	 */
>   99:
>   	li	r0,__NR_clock_getres
> +  .cfi_restore lr
>   	sc
>   	blr
>     .cfi_endproc
> diff --git a/arch/powerpc/kernel/vdso64/gettimeofday.S b/arch/powerpc/kernel/vdso64/gettimeofday.S
> index a4ed9edfd5f0..a7e49bddd475 100644
> --- a/arch/powerpc/kernel/vdso64/gettimeofday.S
> +++ b/arch/powerpc/kernel/vdso64/gettimeofday.S
> @@ -190,14 +190,21 @@ V_FUNCTION_BEGIN(__kernel_clock_getres)
>   	cror	cr0*4+eq,cr0*4+eq,cr1*4+eq
>   	bne	cr0,99f
>   
> -	li	r3,0
> -	cmpldi	cr0,r4,0
> +	mflr	r12
> +  .cfi_register lr,r12
> +	mr	r11, r4
> +	bl	V_LOCAL_FUNC(__get_datapage)
> +	lwz	r5,CLOCK_REALTIME_RES(r3)
> +	li	r4,0
> +	cmpldi	r11,0		/* check if res is NULL */
> +	beq	1f
> +
> +	std	r4,TSPC64_TV_SEC(r11)
> +	std	r5,TSPC64_TV_NSEC(r11)
> +
> +1:	mtlr	r12
>   	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)
> +	li	r3,0
>   	blr

The same type of simplification applies here too.

Christophe


>   
>   	/*
> @@ -205,6 +212,7 @@ V_FUNCTION_BEGIN(__kernel_clock_getres)
>   	 */
>   99:
>   	li	r0,__NR_clock_getres
> +  .cfi_restore lr
>   	sc
>   	blr
>     .cfi_endproc
> 

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Re: [PATCH 2/5] powerpc: Fix vDSO clock_getres()

[Vincenzo Frascino]

On 02/04/2019 07:14, Christophe Leroy wrote:
> 
> 
> On 04/01/2019 11:51 AM, Vincenzo Frascino wrote:
>> 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.
>>
>> 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>
>> ---
>>   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 | 22 +++++++++++++++-------
>>   arch/powerpc/kernel/vdso64/gettimeofday.S | 22 +++++++++++++++-------
>>   5 files changed, 34 insertions(+), 15 deletions(-)
>>
> 
> [...]
> 
>> diff --git a/arch/powerpc/kernel/vdso32/gettimeofday.S b/arch/powerpc/kernel/vdso32/gettimeofday.S
>> index 1e0bc5955a40..b21630079496 100644
>> --- a/arch/powerpc/kernel/vdso32/gettimeofday.S
>> +++ b/arch/powerpc/kernel/vdso32/gettimeofday.S
>> @@ -160,14 +160,21 @@ V_FUNCTION_BEGIN(__kernel_clock_getres)
>>   	cror	cr0*4+eq,cr0*4+eq,cr1*4+eq
>>   	bne	cr0,99f
>>   
>> -	li	r3,0
>> -	cmpli	cr0,r4,0
>> +	mflr	r12
>> +  .cfi_register lr,r12
>> +	mr	r11,r4
>> +	bl	__get_datapage@local
>> +	lwz	r5,CLOCK_REALTIME_RES(r3)
>> +	li	r4,0
>> +	cmplwi	r11,0		/* check if res is NULL */
>> +	beq	1f
>> +
>> +	stw	r4,TSPC32_TV_SEC(r11)
>> +	stw	r5,TSPC32_TV_NSEC(r11)
>> +
>> +1:	mtlr	r12
>>   	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)
>> +	li	r3,0
>>   	blr
> 
> The above can be done simpler, see below
> 
> @@ -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
> 

Thank you for this, I will update my code accordingly before posting v2.

> Christophe
> 
>>   
>>   	/*
>> @@ -175,6 +182,7 @@ V_FUNCTION_BEGIN(__kernel_clock_getres)
>>   	 */
>>   99:
>>   	li	r0,__NR_clock_getres
>> +  .cfi_restore lr
>>   	sc
>>   	blr
>>     .cfi_endproc
>> diff --git a/arch/powerpc/kernel/vdso64/gettimeofday.S b/arch/powerpc/kernel/vdso64/gettimeofday.S
>> index a4ed9edfd5f0..a7e49bddd475 100644
>> --- a/arch/powerpc/kernel/vdso64/gettimeofday.S
>> +++ b/arch/powerpc/kernel/vdso64/gettimeofday.S
>> @@ -190,14 +190,21 @@ V_FUNCTION_BEGIN(__kernel_clock_getres)
>>   	cror	cr0*4+eq,cr0*4+eq,cr1*4+eq
>>   	bne	cr0,99f
>>   
>> -	li	r3,0
>> -	cmpldi	cr0,r4,0
>> +	mflr	r12
>> +  .cfi_register lr,r12
>> +	mr	r11, r4
>> +	bl	V_LOCAL_FUNC(__get_datapage)
>> +	lwz	r5,CLOCK_REALTIME_RES(r3)
>> +	li	r4,0
>> +	cmpldi	r11,0		/* check if res is NULL */
>> +	beq	1f
>> +
>> +	std	r4,TSPC64_TV_SEC(r11)
>> +	std	r5,TSPC64_TV_NSEC(r11)
>> +
>> +1:	mtlr	r12
>>   	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)
>> +	li	r3,0
>>   	blr
> 
> The same type of simplification applies here too.
> 
> Christophe
> 
> 
>>   
>>   	/*
>> @@ -205,6 +212,7 @@ V_FUNCTION_BEGIN(__kernel_clock_getres)
>>   	 */
>>   99:
>>   	li	r0,__NR_clock_getres
>> +  .cfi_restore lr
>>   	sc
>>   	blr
>>     .cfi_endproc
>>

-- 
Regards,
Vincenzo

Re: [PATCH 2/5] powerpc: Fix vDSO clock_getres()

[Vincenzo Frascino]

On 02/04/2019 07:14, Christophe Leroy wrote:
> 
> 
> On 04/01/2019 11:51 AM, Vincenzo Frascino wrote:
>> 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.
>>
>> 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>
>> ---
>>   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 | 22 +++++++++++++++-------
>>   arch/powerpc/kernel/vdso64/gettimeofday.S | 22 +++++++++++++++-------
>>   5 files changed, 34 insertions(+), 15 deletions(-)
>>
> 
> [...]
> 
>> diff --git a/arch/powerpc/kernel/vdso32/gettimeofday.S b/arch/powerpc/kernel/vdso32/gettimeofday.S
>> index 1e0bc5955a40..b21630079496 100644
>> --- a/arch/powerpc/kernel/vdso32/gettimeofday.S
>> +++ b/arch/powerpc/kernel/vdso32/gettimeofday.S
>> @@ -160,14 +160,21 @@ V_FUNCTION_BEGIN(__kernel_clock_getres)
>>   	cror	cr0*4+eq,cr0*4+eq,cr1*4+eq
>>   	bne	cr0,99f
>>   
>> -	li	r3,0
>> -	cmpli	cr0,r4,0
>> +	mflr	r12
>> +  .cfi_register lr,r12
>> +	mr	r11,r4
>> +	bl	__get_datapage@local
>> +	lwz	r5,CLOCK_REALTIME_RES(r3)
>> +	li	r4,0
>> +	cmplwi	r11,0		/* check if res is NULL */
>> +	beq	1f
>> +
>> +	stw	r4,TSPC32_TV_SEC(r11)
>> +	stw	r5,TSPC32_TV_NSEC(r11)
>> +
>> +1:	mtlr	r12
>>   	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)
>> +	li	r3,0
>>   	blr
> 
> The above can be done simpler, see below
> 
> @@ -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
> 

Thank you for this, I will update my code accordingly before posting v2.

> Christophe
> 
>>   
>>   	/*
>> @@ -175,6 +182,7 @@ V_FUNCTION_BEGIN(__kernel_clock_getres)
>>   	 */
>>   99:
>>   	li	r0,__NR_clock_getres
>> +  .cfi_restore lr
>>   	sc
>>   	blr
>>     .cfi_endproc
>> diff --git a/arch/powerpc/kernel/vdso64/gettimeofday.S b/arch/powerpc/kernel/vdso64/gettimeofday.S
>> index a4ed9edfd5f0..a7e49bddd475 100644
>> --- a/arch/powerpc/kernel/vdso64/gettimeofday.S
>> +++ b/arch/powerpc/kernel/vdso64/gettimeofday.S
>> @@ -190,14 +190,21 @@ V_FUNCTION_BEGIN(__kernel_clock_getres)
>>   	cror	cr0*4+eq,cr0*4+eq,cr1*4+eq
>>   	bne	cr0,99f
>>   
>> -	li	r3,0
>> -	cmpldi	cr0,r4,0
>> +	mflr	r12
>> +  .cfi_register lr,r12
>> +	mr	r11, r4
>> +	bl	V_LOCAL_FUNC(__get_datapage)
>> +	lwz	r5,CLOCK_REALTIME_RES(r3)
>> +	li	r4,0
>> +	cmpldi	r11,0		/* check if res is NULL */
>> +	beq	1f
>> +
>> +	std	r4,TSPC64_TV_SEC(r11)
>> +	std	r5,TSPC64_TV_NSEC(r11)
>> +
>> +1:	mtlr	r12
>>   	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)
>> +	li	r3,0
>>   	blr
> 
> The same type of simplification applies here too.
> 
> Christophe
> 
> 
>>   
>>   	/*
>> @@ -205,6 +212,7 @@ V_FUNCTION_BEGIN(__kernel_clock_getres)
>>   	 */
>>   99:
>>   	li	r0,__NR_clock_getres
>> +  .cfi_restore lr
>>   	sc
>>   	blr
>>     .cfi_endproc
>>

-- 
Regards,
Vincenzo

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH 3/5] s390: Fix vDSO clock_getres()

[Vincenzo Frascino]

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>
---
 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 | 17 ++++++++++++-----
 arch/s390/kernel/vdso64/clock_getres.S | 15 ++++++++++-----
 5 files changed, 25 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 164bec175628..36db4a9ee703 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 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..00fc50ad228c 100644
--- a/arch/s390/kernel/vdso32/clock_getres.S
+++ b/arch/s390/kernel/vdso32/clock_getres.S
@@ -18,20 +18,27 @@
 __kernel_clock_getres:
 	CFI_STARTPROC
 	basr	%r1,0
-	la	%r1,4f-.(%r1)
+10:	al	%r1,4f-10b(%r1)
+11:	l	%r4,__VDSO_UPD_COUNT+4(%r1)	/* load update counter */
+	tml	%r4,0x0001			/* pending update ? loop */
+	jnz	11b
+	l	%r0,__VDSO_CLOCK_REALTIME_RES(%r1)
+	cl	%r4,__VDSO_UPD_COUNT+4(%r1)	/* check update counter */
+	jne	11b
 	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 +46,6 @@ __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..1400a8df9802 100644
--- a/arch/s390/kernel/vdso64/clock_getres.S
+++ b/arch/s390/kernel/vdso64/clock_getres.S
@@ -17,12 +17,19 @@
 	.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
+11:	lg	%r4,__VDSO_UPD_COUNT(%r1)	/* load update counter */
+	tmll	%r4,0x0001			/* pending update ? loop */
+	jnz	11b
+	l	%r0,__VDSO_CLOCK_REALTIME_RES(%r1)
+	clg	%r4,__VDSO_UPD_COUNT(%r1)	/* check update counter */
+	jne	11b
 	cghi	%r2,__CLOCK_REALTIME
 	je	0f
 	cghi	%r2,__CLOCK_MONOTONIC
@@ -36,7 +43,6 @@ __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 +51,5 @@ __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
-- 
2.21.0

[PATCH 3/5] s390: Fix vDSO clock_getres()

[Vincenzo Frascino]

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>
---
 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 | 17 ++++++++++++-----
 arch/s390/kernel/vdso64/clock_getres.S | 15 ++++++++++-----
 5 files changed, 25 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 164bec175628..36db4a9ee703 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 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..00fc50ad228c 100644
--- a/arch/s390/kernel/vdso32/clock_getres.S
+++ b/arch/s390/kernel/vdso32/clock_getres.S
@@ -18,20 +18,27 @@
 __kernel_clock_getres:
 	CFI_STARTPROC
 	basr	%r1,0
-	la	%r1,4f-.(%r1)
+10:	al	%r1,4f-10b(%r1)
+11:	l	%r4,__VDSO_UPD_COUNT+4(%r1)	/* load update counter */
+	tml	%r4,0x0001			/* pending update ? loop */
+	jnz	11b
+	l	%r0,__VDSO_CLOCK_REALTIME_RES(%r1)
+	cl	%r4,__VDSO_UPD_COUNT+4(%r1)	/* check update counter */
+	jne	11b
 	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 +46,6 @@ __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..1400a8df9802 100644
--- a/arch/s390/kernel/vdso64/clock_getres.S
+++ b/arch/s390/kernel/vdso64/clock_getres.S
@@ -17,12 +17,19 @@
 	.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
+11:	lg	%r4,__VDSO_UPD_COUNT(%r1)	/* load update counter */
+	tmll	%r4,0x0001			/* pending update ? loop */
+	jnz	11b
+	l	%r0,__VDSO_CLOCK_REALTIME_RES(%r1)
+	clg	%r4,__VDSO_UPD_COUNT(%r1)	/* check update counter */
+	jne	11b
 	cghi	%r2,__CLOCK_REALTIME
 	je	0f
 	cghi	%r2,__CLOCK_MONOTONIC
@@ -36,7 +43,6 @@ __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 +51,5 @@ __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
-- 
2.21.0


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH 3/5] s390: Fix vDSO clock_getres()

[Vincenzo Frascino]

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>
---
 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 | 17 ++++++++++++-----
 arch/s390/kernel/vdso64/clock_getres.S | 15 ++++++++++-----
 5 files changed, 25 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 164bec175628..36db4a9ee703 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 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..00fc50ad228c 100644
--- a/arch/s390/kernel/vdso32/clock_getres.S
+++ b/arch/s390/kernel/vdso32/clock_getres.S
@@ -18,20 +18,27 @@
 __kernel_clock_getres:
 	CFI_STARTPROC
 	basr	%r1,0
-	la	%r1,4f-.(%r1)
+10:	al	%r1,4f-10b(%r1)
+11:	l	%r4,__VDSO_UPD_COUNT+4(%r1)	/* load update counter */
+	tml	%r4,0x0001			/* pending update ? loop */
+	jnz	11b
+	l	%r0,__VDSO_CLOCK_REALTIME_RES(%r1)
+	cl	%r4,__VDSO_UPD_COUNT+4(%r1)	/* check update counter */
+	jne	11b
 	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 +46,6 @@ __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..1400a8df9802 100644
--- a/arch/s390/kernel/vdso64/clock_getres.S
+++ b/arch/s390/kernel/vdso64/clock_getres.S
@@ -17,12 +17,19 @@
 	.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
+11:	lg	%r4,__VDSO_UPD_COUNT(%r1)	/* load update counter */
+	tmll	%r4,0x0001			/* pending update ? loop */
+	jnz	11b
+	l	%r0,__VDSO_CLOCK_REALTIME_RES(%r1)
+	clg	%r4,__VDSO_UPD_COUNT(%r1)	/* check update counter */
+	jne	11b
 	cghi	%r2,__CLOCK_REALTIME
 	je	0f
 	cghi	%r2,__CLOCK_MONOTONIC
@@ -36,7 +43,6 @@ __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 +51,5 @@ __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
-- 
2.21.0

[PATCH 3/5] s390: Fix vDSO clock_getres()

[Vincenzo Frascino]

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>
---
 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 | 17 ++++++++++++-----
 arch/s390/kernel/vdso64/clock_getres.S | 15 ++++++++++-----
 5 files changed, 25 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 164bec175628..36db4a9ee703 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 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..00fc50ad228c 100644
--- a/arch/s390/kernel/vdso32/clock_getres.S
+++ b/arch/s390/kernel/vdso32/clock_getres.S
@@ -18,20 +18,27 @@
 __kernel_clock_getres:
 	CFI_STARTPROC
 	basr	%r1,0
-	la	%r1,4f-.(%r1)
+10:	al	%r1,4f-10b(%r1)
+11:	l	%r4,__VDSO_UPD_COUNT+4(%r1)	/* load update counter */
+	tml	%r4,0x0001			/* pending update ? loop */
+	jnz	11b
+	l	%r0,__VDSO_CLOCK_REALTIME_RES(%r1)
+	cl	%r4,__VDSO_UPD_COUNT+4(%r1)	/* check update counter */
+	jne	11b
 	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 +46,6 @@ __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..1400a8df9802 100644
--- a/arch/s390/kernel/vdso64/clock_getres.S
+++ b/arch/s390/kernel/vdso64/clock_getres.S
@@ -17,12 +17,19 @@
 	.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
+11:	lg	%r4,__VDSO_UPD_COUNT(%r1)	/* load update counter */
+	tmll	%r4,0x0001			/* pending update ? loop */
+	jnz	11b
+	l	%r0,__VDSO_CLOCK_REALTIME_RES(%r1)
+	clg	%r4,__VDSO_UPD_COUNT(%r1)	/* check update counter */
+	jne	11b
 	cghi	%r2,__CLOCK_REALTIME
 	je	0f
 	cghi	%r2,__CLOCK_MONOTONIC
@@ -36,7 +43,6 @@ __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 +51,5 @@ __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
-- 
2.21.0

Re: [PATCH 3/5] s390: Fix vDSO clock_getres()

[Martin Schwidefsky]

On Mon,  1 Apr 2019 12:51:50 +0100
Vincenzo Frascino <vincenzo.frascino@arm.com> wrote:

> 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>
> ---
>  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 | 17 ++++++++++++-----
>  arch/s390/kernel/vdso64/clock_getres.S | 15 ++++++++++-----
>  5 files changed, 25 insertions(+), 11 deletions(-)

I tried this patch and in principle this works. In that regard
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

But I wonder if the loop to check the update counter is really
necessary. The hrtimer_resolution value can only changes once with
the first call to hrtimer_switch_to_hres(). With the TOD clock
as the only clock available on s390 we always have the ability
to do hrtimer. It then all depends on the highres=[on|off] kernel
parameter what value we get with clock_getres().

-- 
blue skies,
   Martin.

"Reality continues to ruin my life." - Calvin.

Re: [PATCH 3/5] s390: Fix vDSO clock_getres()

[Martin Schwidefsky]

On Mon,  1 Apr 2019 12:51:50 +0100
Vincenzo Frascino <vincenzo.frascino@arm.com> wrote:

> 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>
> ---
>  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 | 17 ++++++++++++-----
>  arch/s390/kernel/vdso64/clock_getres.S | 15 ++++++++++-----
>  5 files changed, 25 insertions(+), 11 deletions(-)

I tried this patch and in principle this works. In that regard
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

But I wonder if the loop to check the update counter is really
necessary. The hrtimer_resolution value can only changes once with
the first call to hrtimer_switch_to_hres(). With the TOD clock
as the only clock available on s390 we always have the ability
to do hrtimer. It then all depends on the highres=[on|off] kernel
parameter what value we get with clock_getres().

-- 
blue skies,
   Martin.

"Reality continues to ruin my life." - Calvin.


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH 3/5] s390: Fix vDSO clock_getres()

[Martin Schwidefsky]

On Mon,  1 Apr 2019 12:51:50 +0100
Vincenzo Frascino <vincenzo.frascino@arm.com> wrote:

> 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>
> ---
>  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 | 17 ++++++++++++-----
>  arch/s390/kernel/vdso64/clock_getres.S | 15 ++++++++++-----
>  5 files changed, 25 insertions(+), 11 deletions(-)

I tried this patch and in principle this works. In that regard
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

But I wonder if the loop to check the update counter is really
necessary. The hrtimer_resolution value can only changes once with
the first call to hrtimer_switch_to_hres(). With the TOD clock
as the only clock available on s390 we always have the ability
to do hrtimer. It then all depends on the highres=[on|off] kernel
parameter what value we get with clock_getres().

-- 
blue skies,
   Martin.

"Reality continues to ruin my life." - Calvin.

Re: [PATCH 3/5] s390: Fix vDSO clock_getres()

[Martin Schwidefsky]

On Mon,  1 Apr 2019 12:51:50 +0100
Vincenzo Frascino <vincenzo.frascino@arm.com> wrote:

> 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>
> ---
>  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 | 17 ++++++++++++-----
>  arch/s390/kernel/vdso64/clock_getres.S | 15 ++++++++++-----
>  5 files changed, 25 insertions(+), 11 deletions(-)

I tried this patch and in principle this works. In that regard
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

But I wonder if the loop to check the update counter is really
necessary. The hrtimer_resolution value can only changes once with
the first call to hrtimer_switch_to_hres(). With the TOD clock
as the only clock available on s390 we always have the ability
to do hrtimer. It then all depends on the highres=[on|off] kernel
parameter what value we get with clock_getres().

-- 
blue skies,
   Martin.

"Reality continues to ruin my life." - Calvin.

Re: [PATCH 3/5] s390: Fix vDSO clock_getres()

[Thomas Gleixner]

On Wed, 3 Apr 2019, Martin Schwidefsky wrote:

> On Mon,  1 Apr 2019 12:51:50 +0100
> Vincenzo Frascino <vincenzo.frascino@arm.com> wrote:
> 
> > 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>
> > ---
> >  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 | 17 ++++++++++++-----
> >  arch/s390/kernel/vdso64/clock_getres.S | 15 ++++++++++-----
> >  5 files changed, 25 insertions(+), 11 deletions(-)
> 
> I tried this patch and in principle this works. In that regard
> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
> 
> But I wonder if the loop to check the update counter is really
> necessary. The hrtimer_resolution value can only changes once with
> the first call to hrtimer_switch_to_hres(). With the TOD clock
> as the only clock available on s390 we always have the ability
> to do hrtimer. It then all depends on the highres=[on|off] kernel
> parameter what value we get with clock_getres().

Yes, it's not changing after boot anymore.

Thanks,

	tglx

Re: [PATCH 3/5] s390: Fix vDSO clock_getres()

[Thomas Gleixner]

On Wed, 3 Apr 2019, Martin Schwidefsky wrote:

> On Mon,  1 Apr 2019 12:51:50 +0100
> Vincenzo Frascino <vincenzo.frascino@arm.com> wrote:
> 
> > 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>
> > ---
> >  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 | 17 ++++++++++++-----
> >  arch/s390/kernel/vdso64/clock_getres.S | 15 ++++++++++-----
> >  5 files changed, 25 insertions(+), 11 deletions(-)
> 
> I tried this patch and in principle this works. In that regard
> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
> 
> But I wonder if the loop to check the update counter is really
> necessary. The hrtimer_resolution value can only changes once with
> the first call to hrtimer_switch_to_hres(). With the TOD clock
> as the only clock available on s390 we always have the ability
> to do hrtimer. It then all depends on the highres=[on|off] kernel
> parameter what value we get with clock_getres().

Yes, it's not changing after boot anymore.

Thanks,

	tglx

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH 3/5] s390: Fix vDSO clock_getres()

[Thomas Gleixner]

On Wed, 3 Apr 2019, Martin Schwidefsky wrote:

> On Mon,  1 Apr 2019 12:51:50 +0100
> Vincenzo Frascino <vincenzo.frascino@arm.com> wrote:
> 
> > 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>
> > ---
> >  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 | 17 ++++++++++++-----
> >  arch/s390/kernel/vdso64/clock_getres.S | 15 ++++++++++-----
> >  5 files changed, 25 insertions(+), 11 deletions(-)
> 
> I tried this patch and in principle this works. In that regard
> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
> 
> But I wonder if the loop to check the update counter is really
> necessary. The hrtimer_resolution value can only changes once with
> the first call to hrtimer_switch_to_hres(). With the TOD clock
> as the only clock available on s390 we always have the ability
> to do hrtimer. It then all depends on the highres=[on|off] kernel
> parameter what value we get with clock_getres().

Yes, it's not changing after boot anymore.

Thanks,

	tglx

Re: [PATCH 3/5] s390: Fix vDSO clock_getres()

[Thomas Gleixner]

On Wed, 3 Apr 2019, Martin Schwidefsky wrote:

> On Mon,  1 Apr 2019 12:51:50 +0100
> Vincenzo Frascino <vincenzo.frascino@arm.com> wrote:
> 
> > 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>
> > ---
> >  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 | 17 ++++++++++++-----
> >  arch/s390/kernel/vdso64/clock_getres.S | 15 ++++++++++-----
> >  5 files changed, 25 insertions(+), 11 deletions(-)
> 
> I tried this patch and in principle this works. In that regard
> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
> 
> But I wonder if the loop to check the update counter is really
> necessary. The hrtimer_resolution value can only changes once with
> the first call to hrtimer_switch_to_hres(). With the TOD clock
> as the only clock available on s390 we always have the ability
> to do hrtimer. It then all depends on the highres=[on|off] kernel
> parameter what value we get with clock_getres().

Yes, it's not changing after boot anymore.

Thanks,

	tglx

Re: [PATCH 3/5] s390: Fix vDSO clock_getres()

[Vincenzo Frascino]

On 03/04/2019 11:06, Thomas Gleixner wrote:
> On Wed, 3 Apr 2019, Martin Schwidefsky wrote:
> 
>> On Mon,  1 Apr 2019 12:51:50 +0100
>> Vincenzo Frascino <vincenzo.frascino@arm.com> wrote:
>>
>>> 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>
>>> ---
>>>  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 | 17 ++++++++++++-----
>>>  arch/s390/kernel/vdso64/clock_getres.S | 15 ++++++++++-----
>>>  5 files changed, 25 insertions(+), 11 deletions(-)
>>
>> I tried this patch and in principle this works. In that regard
>> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
>>
>> But I wonder if the loop to check the update counter is really
>> necessary. The hrtimer_resolution value can only changes once with
>> the first call to hrtimer_switch_to_hres(). With the TOD clock
>> as the only clock available on s390 we always have the ability
>> to do hrtimer. It then all depends on the highres=[on|off] kernel
>> parameter what value we get with clock_getres().
> 
> Yes, it's not changing after boot anymore.
> 
> Thanks,
> 
> 	tglx
> 

Ok, I will remove the loop from both the implementations and post it with v2.

-- 
Regards,
Vincenzo

Re: [PATCH 3/5] s390: Fix vDSO clock_getres()

[Vincenzo Frascino]

On 03/04/2019 11:06, Thomas Gleixner wrote:
> On Wed, 3 Apr 2019, Martin Schwidefsky wrote:
> 
>> On Mon,  1 Apr 2019 12:51:50 +0100
>> Vincenzo Frascino <vincenzo.frascino@arm.com> wrote:
>>
>>> 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>
>>> ---
>>>  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 | 17 ++++++++++++-----
>>>  arch/s390/kernel/vdso64/clock_getres.S | 15 ++++++++++-----
>>>  5 files changed, 25 insertions(+), 11 deletions(-)
>>
>> I tried this patch and in principle this works. In that regard
>> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
>>
>> But I wonder if the loop to check the update counter is really
>> necessary. The hrtimer_resolution value can only changes once with
>> the first call to hrtimer_switch_to_hres(). With the TOD clock
>> as the only clock available on s390 we always have the ability
>> to do hrtimer. It then all depends on the highres=[on|off] kernel
>> parameter what value we get with clock_getres().
> 
> Yes, it's not changing after boot anymore.
> 
> Thanks,
> 
> 	tglx
> 

Ok, I will remove the loop from both the implementations and post it with v2.

-- 
Regards,
Vincenzo

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH 3/5] s390: Fix vDSO clock_getres()

[Vincenzo Frascino]

On 03/04/2019 11:06, Thomas Gleixner wrote:
> On Wed, 3 Apr 2019, Martin Schwidefsky wrote:
> 
>> On Mon,  1 Apr 2019 12:51:50 +0100
>> Vincenzo Frascino <vincenzo.frascino@arm.com> wrote:
>>
>>> 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>
>>> ---
>>>  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 | 17 ++++++++++++-----
>>>  arch/s390/kernel/vdso64/clock_getres.S | 15 ++++++++++-----
>>>  5 files changed, 25 insertions(+), 11 deletions(-)
>>
>> I tried this patch and in principle this works. In that regard
>> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
>>
>> But I wonder if the loop to check the update counter is really
>> necessary. The hrtimer_resolution value can only changes once with
>> the first call to hrtimer_switch_to_hres(). With the TOD clock
>> as the only clock available on s390 we always have the ability
>> to do hrtimer. It then all depends on the highres=[on|off] kernel
>> parameter what value we get with clock_getres().
> 
> Yes, it's not changing after boot anymore.
> 
> Thanks,
> 
> 	tglx
> 

Ok, I will remove the loop from both the implementations and post it with v2.

-- 
Regards,
Vincenzo

Re: [PATCH 3/5] s390: Fix vDSO clock_getres()

[Vincenzo Frascino]

On 03/04/2019 11:06, Thomas Gleixner wrote:
> On Wed, 3 Apr 2019, Martin Schwidefsky wrote:
> 
>> On Mon,  1 Apr 2019 12:51:50 +0100
>> Vincenzo Frascino <vincenzo.frascino@arm.com> wrote:
>>
>>> 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>
>>> ---
>>>  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 | 17 ++++++++++++-----
>>>  arch/s390/kernel/vdso64/clock_getres.S | 15 ++++++++++-----
>>>  5 files changed, 25 insertions(+), 11 deletions(-)
>>
>> I tried this patch and in principle this works. In that regard
>> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
>>
>> But I wonder if the loop to check the update counter is really
>> necessary. The hrtimer_resolution value can only changes once with
>> the first call to hrtimer_switch_to_hres(). With the TOD clock
>> as the only clock available on s390 we always have the ability
>> to do hrtimer. It then all depends on the highres=[on|off] kernel
>> parameter what value we get with clock_getres().
> 
> Yes, it's not changing after boot anymore.
> 
> Thanks,
> 
> 	tglx
> 

Ok, I will remove the loop from both the implementations and post it with v2.

-- 
Regards,
Vincenzo

[PATCH 4/5] nds32: Fix vDSO clock_getres()

[Vincenzo Frascino]

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 nds32 vdso implementation of clock_getres keeping a copy of
hrtimer_resolution in vdso data and using that directly.

Cc: Greentime Hu <green.hu@gmail.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
---
 arch/nds32/include/asm/vdso_datapage.h | 1 +
 arch/nds32/kernel/vdso.c               | 1 +
 arch/nds32/kernel/vdso/gettimeofday.c  | 4 +++-
 3 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/arch/nds32/include/asm/vdso_datapage.h b/arch/nds32/include/asm/vdso_datapage.h
index 79db5a12ca5e..34d80548297f 100644
--- a/arch/nds32/include/asm/vdso_datapage.h
+++ b/arch/nds32/include/asm/vdso_datapage.h
@@ -20,6 +20,7 @@ struct vdso_data {
 	u32 xtime_clock_sec;	/* CLOCK_REALTIME - seconds */
 	u32 cs_mult;		/* clocksource multiplier */
 	u32 cs_shift;		/* Cycle to nanosecond divisor (power of two) */
+	u32 hrtimer_res;	/* hrtimer resolution */
 
 	u64 cs_cycle_last;	/* last cycle value */
 	u64 cs_mask;		/* clocksource mask */
diff --git a/arch/nds32/kernel/vdso.c b/arch/nds32/kernel/vdso.c
index 016f15891f6d..90bcae6f8554 100644
--- a/arch/nds32/kernel/vdso.c
+++ b/arch/nds32/kernel/vdso.c
@@ -220,6 +220,7 @@ void update_vsyscall(struct timekeeper *tk)
 	vdso_data->xtime_coarse_sec = tk->xtime_sec;
 	vdso_data->xtime_coarse_nsec = tk->tkr_mono.xtime_nsec >>
 	    tk->tkr_mono.shift;
+	vdso_data->hrtimer_res = hrtimer_resolution;
 	vdso_write_end(vdso_data);
 }
 
diff --git a/arch/nds32/kernel/vdso/gettimeofday.c b/arch/nds32/kernel/vdso/gettimeofday.c
index 038721af40e3..b02581891c33 100644
--- a/arch/nds32/kernel/vdso/gettimeofday.c
+++ b/arch/nds32/kernel/vdso/gettimeofday.c
@@ -208,6 +208,8 @@ static notrace int clock_getres_fallback(clockid_t _clk_id,
 
 notrace int __vdso_clock_getres(clockid_t clk_id, struct timespec *res)
 {
+	struct vdso_data *vdata = __get_datapage();
+
 	if (res == NULL)
 		return 0;
 	switch (clk_id) {
@@ -215,7 +217,7 @@ notrace int __vdso_clock_getres(clockid_t clk_id, struct timespec *res)
 	case CLOCK_MONOTONIC:
 	case CLOCK_MONOTONIC_RAW:
 		res->tv_sec = 0;
-		res->tv_nsec = CLOCK_REALTIME_RES;
+		res->tv_nsec = vdata->hrtimer_res;
 		break;
 	case CLOCK_REALTIME_COARSE:
 	case CLOCK_MONOTONIC_COARSE:
-- 
2.21.0

[PATCH 4/5] nds32: Fix vDSO clock_getres()

[Vincenzo Frascino]

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 nds32 vdso implementation of clock_getres keeping a copy of
hrtimer_resolution in vdso data and using that directly.

Cc: Greentime Hu <green.hu@gmail.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
---
 arch/nds32/include/asm/vdso_datapage.h | 1 +
 arch/nds32/kernel/vdso.c               | 1 +
 arch/nds32/kernel/vdso/gettimeofday.c  | 4 +++-
 3 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/arch/nds32/include/asm/vdso_datapage.h b/arch/nds32/include/asm/vdso_datapage.h
index 79db5a12ca5e..34d80548297f 100644
--- a/arch/nds32/include/asm/vdso_datapage.h
+++ b/arch/nds32/include/asm/vdso_datapage.h
@@ -20,6 +20,7 @@ struct vdso_data {
 	u32 xtime_clock_sec;	/* CLOCK_REALTIME - seconds */
 	u32 cs_mult;		/* clocksource multiplier */
 	u32 cs_shift;		/* Cycle to nanosecond divisor (power of two) */
+	u32 hrtimer_res;	/* hrtimer resolution */
 
 	u64 cs_cycle_last;	/* last cycle value */
 	u64 cs_mask;		/* clocksource mask */
diff --git a/arch/nds32/kernel/vdso.c b/arch/nds32/kernel/vdso.c
index 016f15891f6d..90bcae6f8554 100644
--- a/arch/nds32/kernel/vdso.c
+++ b/arch/nds32/kernel/vdso.c
@@ -220,6 +220,7 @@ void update_vsyscall(struct timekeeper *tk)
 	vdso_data->xtime_coarse_sec = tk->xtime_sec;
 	vdso_data->xtime_coarse_nsec = tk->tkr_mono.xtime_nsec >>
 	    tk->tkr_mono.shift;
+	vdso_data->hrtimer_res = hrtimer_resolution;
 	vdso_write_end(vdso_data);
 }
 
diff --git a/arch/nds32/kernel/vdso/gettimeofday.c b/arch/nds32/kernel/vdso/gettimeofday.c
index 038721af40e3..b02581891c33 100644
--- a/arch/nds32/kernel/vdso/gettimeofday.c
+++ b/arch/nds32/kernel/vdso/gettimeofday.c
@@ -208,6 +208,8 @@ static notrace int clock_getres_fallback(clockid_t _clk_id,
 
 notrace int __vdso_clock_getres(clockid_t clk_id, struct timespec *res)
 {
+	struct vdso_data *vdata = __get_datapage();
+
 	if (res == NULL)
 		return 0;
 	switch (clk_id) {
@@ -215,7 +217,7 @@ notrace int __vdso_clock_getres(clockid_t clk_id, struct timespec *res)
 	case CLOCK_MONOTONIC:
 	case CLOCK_MONOTONIC_RAW:
 		res->tv_sec = 0;
-		res->tv_nsec = CLOCK_REALTIME_RES;
+		res->tv_nsec = vdata->hrtimer_res;
 		break;
 	case CLOCK_REALTIME_COARSE:
 	case CLOCK_MONOTONIC_COARSE:
-- 
2.21.0


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[PATCH 4/5] nds32: Fix vDSO clock_getres()

[Vincenzo Frascino]

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 nds32 vdso implementation of clock_getres keeping a copy of
hrtimer_resolution in vdso data and using that directly.

Cc: Greentime Hu <green.hu@gmail.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
---
 arch/nds32/include/asm/vdso_datapage.h | 1 +
 arch/nds32/kernel/vdso.c               | 1 +
 arch/nds32/kernel/vdso/gettimeofday.c  | 4 +++-
 3 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/arch/nds32/include/asm/vdso_datapage.h b/arch/nds32/include/asm/vdso_datapage.h
index 79db5a12ca5e..34d80548297f 100644
--- a/arch/nds32/include/asm/vdso_datapage.h
+++ b/arch/nds32/include/asm/vdso_datapage.h
@@ -20,6 +20,7 @@ struct vdso_data {
 	u32 xtime_clock_sec;	/* CLOCK_REALTIME - seconds */
 	u32 cs_mult;		/* clocksource multiplier */
 	u32 cs_shift;		/* Cycle to nanosecond divisor (power of two) */
+	u32 hrtimer_res;	/* hrtimer resolution */
 
 	u64 cs_cycle_last;	/* last cycle value */
 	u64 cs_mask;		/* clocksource mask */
diff --git a/arch/nds32/kernel/vdso.c b/arch/nds32/kernel/vdso.c
index 016f15891f6d..90bcae6f8554 100644
--- a/arch/nds32/kernel/vdso.c
+++ b/arch/nds32/kernel/vdso.c
@@ -220,6 +220,7 @@ void update_vsyscall(struct timekeeper *tk)
 	vdso_data->xtime_coarse_sec = tk->xtime_sec;
 	vdso_data->xtime_coarse_nsec = tk->tkr_mono.xtime_nsec >>
 	    tk->tkr_mono.shift;
+	vdso_data->hrtimer_res = hrtimer_resolution;
 	vdso_write_end(vdso_data);
 }
 
diff --git a/arch/nds32/kernel/vdso/gettimeofday.c b/arch/nds32/kernel/vdso/gettimeofday.c
index 038721af40e3..b02581891c33 100644
--- a/arch/nds32/kernel/vdso/gettimeofday.c
+++ b/arch/nds32/kernel/vdso/gettimeofday.c
@@ -208,6 +208,8 @@ static notrace int clock_getres_fallback(clockid_t _clk_id,
 
 notrace int __vdso_clock_getres(clockid_t clk_id, struct timespec *res)
 {
+	struct vdso_data *vdata = __get_datapage();
+
 	if (res == NULL)
 		return 0;
 	switch (clk_id) {
@@ -215,7 +217,7 @@ notrace int __vdso_clock_getres(clockid_t clk_id, struct timespec *res)
 	case CLOCK_MONOTONIC:
 	case CLOCK_MONOTONIC_RAW:
 		res->tv_sec = 0;
-		res->tv_nsec = CLOCK_REALTIME_RES;
+		res->tv_nsec = vdata->hrtimer_res;
 		break;
 	case CLOCK_REALTIME_COARSE:
 	case CLOCK_MONOTONIC_COARSE:
-- 
2.21.0

[PATCH 4/5] nds32: Fix vDSO clock_getres()

[Vincenzo Frascino]

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 nds32 vdso implementation of clock_getres keeping a copy of
hrtimer_resolution in vdso data and using that directly.

Cc: Greentime Hu <green.hu@gmail.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
---
 arch/nds32/include/asm/vdso_datapage.h | 1 +
 arch/nds32/kernel/vdso.c               | 1 +
 arch/nds32/kernel/vdso/gettimeofday.c  | 4 +++-
 3 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/arch/nds32/include/asm/vdso_datapage.h b/arch/nds32/include/asm/vdso_datapage.h
index 79db5a12ca5e..34d80548297f 100644
--- a/arch/nds32/include/asm/vdso_datapage.h
+++ b/arch/nds32/include/asm/vdso_datapage.h
@@ -20,6 +20,7 @@ struct vdso_data {
 	u32 xtime_clock_sec;	/* CLOCK_REALTIME - seconds */
 	u32 cs_mult;		/* clocksource multiplier */
 	u32 cs_shift;		/* Cycle to nanosecond divisor (power of two) */
+	u32 hrtimer_res;	/* hrtimer resolution */
 
 	u64 cs_cycle_last;	/* last cycle value */
 	u64 cs_mask;		/* clocksource mask */
diff --git a/arch/nds32/kernel/vdso.c b/arch/nds32/kernel/vdso.c
index 016f15891f6d..90bcae6f8554 100644
--- a/arch/nds32/kernel/vdso.c
+++ b/arch/nds32/kernel/vdso.c
@@ -220,6 +220,7 @@ void update_vsyscall(struct timekeeper *tk)
 	vdso_data->xtime_coarse_sec = tk->xtime_sec;
 	vdso_data->xtime_coarse_nsec = tk->tkr_mono.xtime_nsec >>
 	    tk->tkr_mono.shift;
+	vdso_data->hrtimer_res = hrtimer_resolution;
 	vdso_write_end(vdso_data);
 }
 
diff --git a/arch/nds32/kernel/vdso/gettimeofday.c b/arch/nds32/kernel/vdso/gettimeofday.c
index 038721af40e3..b02581891c33 100644
--- a/arch/nds32/kernel/vdso/gettimeofday.c
+++ b/arch/nds32/kernel/vdso/gettimeofday.c
@@ -208,6 +208,8 @@ static notrace int clock_getres_fallback(clockid_t _clk_id,
 
 notrace int __vdso_clock_getres(clockid_t clk_id, struct timespec *res)
 {
+	struct vdso_data *vdata = __get_datapage();
+
 	if (res == NULL)
 		return 0;
 	switch (clk_id) {
@@ -215,7 +217,7 @@ notrace int __vdso_clock_getres(clockid_t clk_id, struct timespec *res)
 	case CLOCK_MONOTONIC:
 	case CLOCK_MONOTONIC_RAW:
 		res->tv_sec = 0;
-		res->tv_nsec = CLOCK_REALTIME_RES;
+		res->tv_nsec = vdata->hrtimer_res;
 		break;
 	case CLOCK_REALTIME_COARSE:
 	case CLOCK_MONOTONIC_COARSE:
-- 
2.21.0

[PATCH 5/5] kselftest: Extend vDSO selftest to clock_getres

[Vincenzo Frascino]

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>
---
 tools/testing/selftests/vDSO/Makefile         |   2 +
 .../selftests/vDSO/vdso_clock_getres.c        | 107 ++++++++++++++++++
 2 files changed, 109 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..589949f6ca90
--- /dev/null
+++ b/tools/testing/selftests/vDSO/vdso_clock_getres.c
@@ -0,0 +1,107 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * 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.
+ */
+#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>
+#define _GNU_SOURCE
+#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",
+};
+
+/*
+ * Macro to call clock_getres in vdso and by system call
+ * with different values for clock_id.
+ */
+#define vdso_test_clock(clock_id)				\
+do {								\
+	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_sec != y.tv_sec)) {	\
+		printf(" [FAIL]\n");				\
+		return KSFT_SKIP;				\
+	} else {						\
+		printf(" [PASS]\n");				\
+	}							\
+} while (0)
+
+int main(int argc, char **argv)
+{
+
+#if _POSIX_TIMERS > 0
+
+#ifdef CLOCK_REALTIME
+	vdso_test_clock(CLOCK_REALTIME);
+#endif
+
+#ifdef CLOCK_BOOTTIME
+	vdso_test_clock(CLOCK_BOOTTIME);
+#endif
+
+#ifdef CLOCK_TAI
+	vdso_test_clock(CLOCK_TAI);
+#endif
+
+#ifdef CLOCK_REALTIME_COARSE
+	vdso_test_clock(CLOCK_REALTIME_COARSE);
+#endif
+
+#ifdef CLOCK_MONOTONIC
+	vdso_test_clock(CLOCK_MONOTONIC);
+#endif
+
+#ifdef CLOCK_MONOTONIC_RAW
+	vdso_test_clock(CLOCK_MONOTONIC_RAW);
+#endif
+
+#ifdef CLOCK_MONOTONIC_COARSE
+	vdso_test_clock(CLOCK_MONOTONIC_COARSE);
+#endif
+
+#endif
+
+	return 0;
+}
-- 
2.21.0

[PATCH 5/5] kselftest: Extend vDSO selftest to clock_getres

[Vincenzo Frascino]

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>
---
 tools/testing/selftests/vDSO/Makefile         |   2 +
 .../selftests/vDSO/vdso_clock_getres.c        | 107 ++++++++++++++++++
 2 files changed, 109 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..589949f6ca90
--- /dev/null
+++ b/tools/testing/selftests/vDSO/vdso_clock_getres.c
@@ -0,0 +1,107 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * 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.
+ */
+#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>
+#define _GNU_SOURCE
+#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",
+};
+
+/*
+ * Macro to call clock_getres in vdso and by system call
+ * with different values for clock_id.
+ */
+#define vdso_test_clock(clock_id)				\
+do {								\
+	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_sec != y.tv_sec)) {	\
+		printf(" [FAIL]\n");				\
+		return KSFT_SKIP;				\
+	} else {						\
+		printf(" [PASS]\n");				\
+	}							\
+} while (0)
+
+int main(int argc, char **argv)
+{
+
+#if _POSIX_TIMERS > 0
+
+#ifdef CLOCK_REALTIME
+	vdso_test_clock(CLOCK_REALTIME);
+#endif
+
+#ifdef CLOCK_BOOTTIME
+	vdso_test_clock(CLOCK_BOOTTIME);
+#endif
+
+#ifdef CLOCK_TAI
+	vdso_test_clock(CLOCK_TAI);
+#endif
+
+#ifdef CLOCK_REALTIME_COARSE
+	vdso_test_clock(CLOCK_REALTIME_COARSE);
+#endif
+
+#ifdef CLOCK_MONOTONIC
+	vdso_test_clock(CLOCK_MONOTONIC);
+#endif
+
+#ifdef CLOCK_MONOTONIC_RAW
+	vdso_test_clock(CLOCK_MONOTONIC_RAW);
+#endif
+
+#ifdef CLOCK_MONOTONIC_COARSE
+	vdso_test_clock(CLOCK_MONOTONIC_COARSE);
+#endif
+
+#endif
+
+	return 0;
+}
-- 
2.21.0


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH 5/5] kselftest: Extend vDSO selftest to clock_getres

[Vincenzo Frascino]

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>
---
 tools/testing/selftests/vDSO/Makefile         |   2 +
 .../selftests/vDSO/vdso_clock_getres.c        | 107 ++++++++++++++++++
 2 files changed, 109 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..589949f6ca90
--- /dev/null
+++ b/tools/testing/selftests/vDSO/vdso_clock_getres.c
@@ -0,0 +1,107 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * 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.
+ */
+#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>
+#define _GNU_SOURCE
+#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",
+};
+
+/*
+ * Macro to call clock_getres in vdso and by system call
+ * with different values for clock_id.
+ */
+#define vdso_test_clock(clock_id)				\
+do {								\
+	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_sec != y.tv_sec)) {	\
+		printf(" [FAIL]\n");				\
+		return KSFT_SKIP;				\
+	} else {						\
+		printf(" [PASS]\n");				\
+	}							\
+} while (0)
+
+int main(int argc, char **argv)
+{
+
+#if _POSIX_TIMERS > 0
+
+#ifdef CLOCK_REALTIME
+	vdso_test_clock(CLOCK_REALTIME);
+#endif
+
+#ifdef CLOCK_BOOTTIME
+	vdso_test_clock(CLOCK_BOOTTIME);
+#endif
+
+#ifdef CLOCK_TAI
+	vdso_test_clock(CLOCK_TAI);
+#endif
+
+#ifdef CLOCK_REALTIME_COARSE
+	vdso_test_clock(CLOCK_REALTIME_COARSE);
+#endif
+
+#ifdef CLOCK_MONOTONIC
+	vdso_test_clock(CLOCK_MONOTONIC);
+#endif
+
+#ifdef CLOCK_MONOTONIC_RAW
+	vdso_test_clock(CLOCK_MONOTONIC_RAW);
+#endif
+
+#ifdef CLOCK_MONOTONIC_COARSE
+	vdso_test_clock(CLOCK_MONOTONIC_COARSE);
+#endif
+
+#endif
+
+	return 0;
+}
-- 
2.21.0

[PATCH 5/5] kselftest: Extend vDSO selftest to clock_getres

[Vincenzo Frascino]

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>
---
 tools/testing/selftests/vDSO/Makefile         |   2 +
 .../selftests/vDSO/vdso_clock_getres.c        | 107 ++++++++++++++++++
 2 files changed, 109 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..589949f6ca90
--- /dev/null
+++ b/tools/testing/selftests/vDSO/vdso_clock_getres.c
@@ -0,0 +1,107 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * 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.
+ */
+#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>
+#define _GNU_SOURCE
+#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",
+};
+
+/*
+ * Macro to call clock_getres in vdso and by system call
+ * with different values for clock_id.
+ */
+#define vdso_test_clock(clock_id)				\
+do {								\
+	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_sec != y.tv_sec)) {	\
+		printf(" [FAIL]\n");				\
+		return KSFT_SKIP;				\
+	} else {						\
+		printf(" [PASS]\n");				\
+	}							\
+} while (0)
+
+int main(int argc, char **argv)
+{
+
+#if _POSIX_TIMERS > 0
+
+#ifdef CLOCK_REALTIME
+	vdso_test_clock(CLOCK_REALTIME);
+#endif
+
+#ifdef CLOCK_BOOTTIME
+	vdso_test_clock(CLOCK_BOOTTIME);
+#endif
+
+#ifdef CLOCK_TAI
+	vdso_test_clock(CLOCK_TAI);
+#endif
+
+#ifdef CLOCK_REALTIME_COARSE
+	vdso_test_clock(CLOCK_REALTIME_COARSE);
+#endif
+
+#ifdef CLOCK_MONOTONIC
+	vdso_test_clock(CLOCK_MONOTONIC);
+#endif
+
+#ifdef CLOCK_MONOTONIC_RAW
+	vdso_test_clock(CLOCK_MONOTONIC_RAW);
+#endif
+
+#ifdef CLOCK_MONOTONIC_COARSE
+	vdso_test_clock(CLOCK_MONOTONIC_COARSE);
+#endif
+
+#endif
+
+	return 0;
+}
-- 
2.21.0