[PATCH 0/3] arm: Enable unified vDSO

[PATCH 0/3] arm: Enable unified vDSO

[Vincenzo Frascino]

This patch series is a follow up of [1] and enables the unified vDSO
library in the arm architecture.

The porting has been validated using the vdsotest test-suite [2]
extended to cover all the clock ids [3].

[1] https://patchwork.kernel.org/cover/11009649/
[2] https://github.com/nathanlynch/vdsotest
[3] https://github.com/fvincenzo/vdsotest

Cc: Russell King <linux@armlinux.org.uk>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>

Vincenzo Frascino (3):
  arm: Add support for generic vDSO
  arm: Add clock_getres entry point
  arm: Add clock_gettime64 entry point

 arch/arm/include/asm/vdso/gettimeofday.h |  94 +++++++++
 arch/arm/include/asm/vdso/vsyscall.h     |  71 +++++++
 arch/arm/include/asm/vdso_datapage.h     |  29 +--
 arch/arm/kernel/vdso.c                   |  87 +-------
 arch/arm/mm/Kconfig                      |   3 +
 arch/arm/vdso/Makefile                   |  18 +-
 arch/arm/vdso/note.c                     |  15 ++
 arch/arm/vdso/vdso.lds.S                 |   2 +
 arch/arm/vdso/vgettimeofday.c            | 255 ++---------------------
 9 files changed, 223 insertions(+), 351 deletions(-)
 create mode 100644 arch/arm/include/asm/vdso/gettimeofday.h
 create mode 100644 arch/arm/include/asm/vdso/vsyscall.h
 create mode 100644 arch/arm/vdso/note.c

-- 
2.23.0


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

[PATCH 1/3] arm: Add support for generic vDSO

[Vincenzo Frascino]

The arm vDSO library requires some adaptations to take advantage of
the newly introduced generic vDSO library.

Introduce the following changes:
 - Modification vdso.c to be compliant with the common vdso datapage
 - Use of lib/vdso for gettimeofday
 - Implementation of elf note

Cc: Russell King <linux@armlinux.org.uk>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
---
 arch/arm/include/asm/vdso/gettimeofday.h |  74 +++++++
 arch/arm/include/asm/vdso/vsyscall.h     |  71 +++++++
 arch/arm/include/asm/vdso_datapage.h     |  29 +--
 arch/arm/kernel/vdso.c                   |  87 +-------
 arch/arm/mm/Kconfig                      |   3 +
 arch/arm/vdso/Makefile                   |  18 +-
 arch/arm/vdso/note.c                     |  15 ++
 arch/arm/vdso/vgettimeofday.c            | 255 +----------------------
 8 files changed, 195 insertions(+), 357 deletions(-)
 create mode 100644 arch/arm/include/asm/vdso/gettimeofday.h
 create mode 100644 arch/arm/include/asm/vdso/vsyscall.h
 create mode 100644 arch/arm/vdso/note.c

diff --git a/arch/arm/include/asm/vdso/gettimeofday.h b/arch/arm/include/asm/vdso/gettimeofday.h
new file mode 100644
index 000000000000..30ce4e87dffc
--- /dev/null
+++ b/arch/arm/include/asm/vdso/gettimeofday.h
@@ -0,0 +1,74 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2018 ARM Limited
+ */
+#ifndef __ASM_VDSO_GETTIMEOFDAY_H
+#define __ASM_VDSO_GETTIMEOFDAY_H
+
+#ifndef __ASSEMBLY__
+
+#include <asm/barrier.h>
+#include <asm/cp15.h>
+#include <asm/unistd.h>
+#include <uapi/linux/time.h>
+
+extern struct vdso_data *__get_datapage(void);
+
+static __always_inline int gettimeofday_fallback(
+				struct __kernel_old_timeval *_tv,
+				struct timezone *_tz)
+{
+	register struct timezone *tz asm("r1") = _tz;
+	register struct __kernel_old_timeval *tv asm("r0") = _tv;
+	register long ret asm ("r0");
+	register long nr asm("r7") = __NR_gettimeofday;
+
+	asm volatile(
+	"	swi #0\n"
+	: "=r" (ret)
+	: "r" (tv), "r" (tz), "r" (nr)
+	: "memory");
+
+	return ret;
+}
+
+static __always_inline long clock_gettime_fallback(
+					clockid_t _clkid,
+					struct __kernel_timespec *_ts)
+{
+	register struct __kernel_timespec *ts asm("r1") = _ts;
+	register clockid_t clkid asm("r0") = _clkid;
+	register long ret asm ("r0");
+	register long nr asm("r7") = __NR_clock_gettime64;
+
+	asm volatile(
+	"	swi #0\n"
+	: "=r" (ret)
+	: "r" (clkid), "r" (ts), "r" (nr)
+	: "memory");
+
+	return ret;
+}
+
+static __always_inline u64 __arch_get_hw_counter(int clock_mode)
+{
+#ifdef CONFIG_ARM_ARCH_TIMER
+	u64 cycle_now;
+
+	isb();
+	cycle_now = read_sysreg(CNTVCT);
+
+	return cycle_now;
+#else
+	return -EINVAL; /* use fallback */
+#endif
+}
+
+static __always_inline const struct vdso_data *__arch_get_vdso_data(void)
+{
+	return __get_datapage();
+}
+
+#endif /* !__ASSEMBLY__ */
+
+#endif /* __ASM_VDSO_GETTIMEOFDAY_H */
diff --git a/arch/arm/include/asm/vdso/vsyscall.h b/arch/arm/include/asm/vdso/vsyscall.h
new file mode 100644
index 000000000000..c4166f317071
--- /dev/null
+++ b/arch/arm/include/asm/vdso/vsyscall.h
@@ -0,0 +1,71 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ASM_VDSO_VSYSCALL_H
+#define __ASM_VDSO_VSYSCALL_H
+
+#ifndef __ASSEMBLY__
+
+#include <linux/timekeeper_internal.h>
+#include <vdso/datapage.h>
+#include <asm/cacheflush.h>
+
+extern struct vdso_data *vdso_data;
+extern bool cntvct_ok;
+
+static __always_inline
+bool tk_is_cntvct(const struct timekeeper *tk)
+{
+	if (!IS_ENABLED(CONFIG_ARM_ARCH_TIMER))
+		return false;
+
+	if (!tk->tkr_mono.clock->archdata.vdso_direct)
+		return false;
+
+	return true;
+}
+
+/*
+ * Update the vDSO data page to keep in sync with kernel timekeeping.
+ */
+static __always_inline
+struct vdso_data *__arm_get_k_vdso_data(void)
+{
+	return vdso_data;
+}
+#define __arch_get_k_vdso_data __arm_get_k_vdso_data
+
+static __always_inline
+int __arm_update_vdso_data(void)
+{
+	return !cntvct_ok;
+}
+#define __arch_update_vdso_data __arm_update_vdso_data
+
+static __always_inline
+int __arm_get_clock_mode(struct timekeeper *tk)
+{
+	u32 __tk_is_cntvct = tk_is_cntvct(tk);
+
+	return __tk_is_cntvct;
+}
+#define __arch_get_clock_mode __arm_get_clock_mode
+
+static __always_inline
+int __arm_use_vsyscall(struct vdso_data *vdata)
+{
+	return vdata[CS_HRES_COARSE].clock_mode;
+}
+#define __arch_use_vsyscall __arm_use_vsyscall
+
+static __always_inline
+void __arm_sync_vdso_data(struct vdso_data *vdata)
+{
+	flush_dcache_page(virt_to_page(vdata));
+}
+#define __arch_sync_vdso_data __arm_sync_vdso_data
+
+/* The asm-generic header needs to be included after the definitions above */
+#include <asm-generic/vdso/vsyscall.h>
+
+#endif /* !__ASSEMBLY__ */
+
+#endif /* __ASM_VDSO_VSYSCALL_H */
diff --git a/arch/arm/include/asm/vdso_datapage.h b/arch/arm/include/asm/vdso_datapage.h
index 7910abf89b1c..bef68f59928d 100644
--- a/arch/arm/include/asm/vdso_datapage.h
+++ b/arch/arm/include/asm/vdso_datapage.h
@@ -11,35 +11,12 @@
 
 #ifndef __ASSEMBLY__
 
+#include <vdso/datapage.h>
 #include <asm/page.h>
 
-/* Try to be cache-friendly on systems that don't implement the
- * generic timer: fit the unconditionally updated fields in the first
- * 32 bytes.
- */
-struct vdso_data {
-	u32 seq_count;		/* sequence count - odd during updates */
-	u16 tk_is_cntvct;	/* fall back to syscall if false */
-	u16 cs_shift;		/* clocksource shift */
-	u32 xtime_coarse_sec;	/* coarse time */
-	u32 xtime_coarse_nsec;
-
-	u32 wtm_clock_sec;	/* wall to monotonic offset */
-	u32 wtm_clock_nsec;
-	u32 xtime_clock_sec;	/* CLOCK_REALTIME - seconds */
-	u32 cs_mult;		/* clocksource multiplier */
-
-	u64 cs_cycle_last;	/* last cycle value */
-	u64 cs_mask;		/* clocksource mask */
-
-	u64 xtime_clock_snsec;	/* CLOCK_REALTIME sub-ns base */
-	u32 tz_minuteswest;	/* timezone info for gettimeofday(2) */
-	u32 tz_dsttime;
-};
-
 union vdso_data_store {
-	struct vdso_data data;
-	u8 page[PAGE_SIZE];
+	struct vdso_data	data[CS_BASES];
+	u8			page[PAGE_SIZE];
 };
 
 #endif /* !__ASSEMBLY__ */
diff --git a/arch/arm/kernel/vdso.c b/arch/arm/kernel/vdso.c
index 9bf16c93ee6a..c89ac1b9d28b 100644
--- a/arch/arm/kernel/vdso.c
+++ b/arch/arm/kernel/vdso.c
@@ -23,6 +23,8 @@
 #include <asm/vdso.h>
 #include <asm/vdso_datapage.h>
 #include <clocksource/arm_arch_timer.h>
+#include <vdso/helpers.h>
+#include <vdso/vsyscall.h>
 
 #define MAX_SYMNAME	64
 
@@ -37,7 +39,7 @@ unsigned int vdso_total_pages __ro_after_init;
  * The VDSO data page.
  */
 static union vdso_data_store vdso_data_store __page_aligned_data;
-static struct vdso_data *vdso_data = &vdso_data_store.data;
+struct vdso_data *vdso_data = vdso_data_store.data;
 
 static struct page *vdso_data_page __ro_after_init;
 static const struct vm_special_mapping vdso_data_mapping = {
@@ -77,7 +79,7 @@ struct elfinfo {
 /* Cached result of boot-time check for whether the arch timer exists,
  * and if so, whether the virtual counter is useable.
  */
-static bool cntvct_ok __ro_after_init;
+bool cntvct_ok __ro_after_init;
 
 static bool __init cntvct_functional(void)
 {
@@ -262,84 +264,3 @@ void arm_install_vdso(struct mm_struct *mm, unsigned long addr)
 		mm->context.vdso = addr;
 }
 
-static void vdso_write_begin(struct vdso_data *vdata)
-{
-	++vdso_data->seq_count;
-	smp_wmb(); /* Pairs with smp_rmb in vdso_read_retry */
-}
-
-static void vdso_write_end(struct vdso_data *vdata)
-{
-	smp_wmb(); /* Pairs with smp_rmb in vdso_read_begin */
-	++vdso_data->seq_count;
-}
-
-static bool tk_is_cntvct(const struct timekeeper *tk)
-{
-	if (!IS_ENABLED(CONFIG_ARM_ARCH_TIMER))
-		return false;
-
-	if (!tk->tkr_mono.clock->archdata.vdso_direct)
-		return false;
-
-	return true;
-}
-
-/**
- * update_vsyscall - update the vdso data page
- *
- * Increment the sequence counter, making it odd, indicating to
- * userspace that an update is in progress.  Update the fields used
- * for coarse clocks and, if the architected system timer is in use,
- * the fields used for high precision clocks.  Increment the sequence
- * counter again, making it even, indicating to userspace that the
- * update is finished.
- *
- * Userspace is expected to sample seq_count before reading any other
- * fields from the data page.  If seq_count is odd, userspace is
- * expected to wait until it becomes even.  After copying data from
- * the page, userspace must sample seq_count again; if it has changed
- * from its previous value, userspace must retry the whole sequence.
- *
- * Calls to update_vsyscall are serialized by the timekeeping core.
- */
-void update_vsyscall(struct timekeeper *tk)
-{
-	struct timespec64 *wtm = &tk->wall_to_monotonic;
-
-	if (!cntvct_ok) {
-		/* The entry points have been zeroed, so there is no
-		 * point in updating the data page.
-		 */
-		return;
-	}
-
-	vdso_write_begin(vdso_data);
-
-	vdso_data->tk_is_cntvct			= tk_is_cntvct(tk);
-	vdso_data->xtime_coarse_sec		= tk->xtime_sec;
-	vdso_data->xtime_coarse_nsec		= (u32)(tk->tkr_mono.xtime_nsec >>
-							tk->tkr_mono.shift);
-	vdso_data->wtm_clock_sec		= wtm->tv_sec;
-	vdso_data->wtm_clock_nsec		= wtm->tv_nsec;
-
-	if (vdso_data->tk_is_cntvct) {
-		vdso_data->cs_cycle_last	= tk->tkr_mono.cycle_last;
-		vdso_data->xtime_clock_sec	= tk->xtime_sec;
-		vdso_data->xtime_clock_snsec	= tk->tkr_mono.xtime_nsec;
-		vdso_data->cs_mult		= tk->tkr_mono.mult;
-		vdso_data->cs_shift		= tk->tkr_mono.shift;
-		vdso_data->cs_mask		= tk->tkr_mono.mask;
-	}
-
-	vdso_write_end(vdso_data);
-
-	flush_dcache_page(virt_to_page(vdso_data));
-}
-
-void update_vsyscall_tz(void)
-{
-	vdso_data->tz_minuteswest	= sys_tz.tz_minuteswest;
-	vdso_data->tz_dsttime		= sys_tz.tz_dsttime;
-	flush_dcache_page(virt_to_page(vdso_data));
-}
diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig
index 0ab3a86b1f52..f112dde735de 100644
--- a/arch/arm/mm/Kconfig
+++ b/arch/arm/mm/Kconfig
@@ -896,7 +896,10 @@ config VDSO
 	bool "Enable VDSO for acceleration of some system calls"
 	depends on AEABI && MMU && CPU_V7
 	default y if ARM_ARCH_TIMER
+	select HAVE_GENERIC_VDSO
 	select GENERIC_TIME_VSYSCALL
+	select GENERIC_VDSO_32
+	select GENERIC_GETTIMEOFDAY
 	help
 	  Place in the process address space an ELF shared object
 	  providing fast implementations of gettimeofday and
diff --git a/arch/arm/vdso/Makefile b/arch/arm/vdso/Makefile
index 87b7769214e0..0fda344beb0b 100644
--- a/arch/arm/vdso/Makefile
+++ b/arch/arm/vdso/Makefile
@@ -1,7 +1,13 @@
 # SPDX-License-Identifier: GPL-2.0
+
+# Absolute relocation type $(ARCH_REL_TYPE_ABS) needs to be defined before
+# the inclusion of generic Makefile.
+ARCH_REL_TYPE_ABS := R_ARM_JUMP_SLOT|R_ARM_GLOB_DAT|R_ARM_ABS32
+include $(srctree)/lib/vdso/Makefile
+
 hostprogs-y := vdsomunge
 
-obj-vdso := vgettimeofday.o datapage.o
+obj-vdso := vgettimeofday.o datapage.o note.o
 
 # Build rules
 targets := $(obj-vdso) vdso.so vdso.so.dbg vdso.so.raw vdso.lds
@@ -24,7 +30,11 @@ CFLAGS_REMOVE_vdso.o = -pg
 
 # Force -O2 to avoid libgcc dependencies
 CFLAGS_REMOVE_vgettimeofday.o = -pg -Os
+ifeq ($(c-gettimeofday-y),)
 CFLAGS_vgettimeofday.o = -O2
+else
+CFLAGS_vgettimeofday.o = -O2 -include $(c-gettimeofday-y)
+endif
 
 # Disable gcov profiling for VDSO code
 GCOV_PROFILE := n
@@ -37,7 +47,7 @@ $(obj)/vdso.o : $(obj)/vdso.so
 
 # Link rule for the .so file
 $(obj)/vdso.so.raw: $(obj)/vdso.lds $(obj-vdso) FORCE
-	$(call if_changed,ld)
+	$(call if_changed,vdsold_and_vdso_check)
 
 $(obj)/vdso.so.dbg: $(obj)/vdso.so.raw $(obj)/vdsomunge FORCE
 	$(call if_changed,vdsomunge)
@@ -47,6 +57,10 @@ $(obj)/%.so: OBJCOPYFLAGS := -S
 $(obj)/%.so: $(obj)/%.so.dbg FORCE
 	$(call if_changed,objcopy)
 
+# Actual build commands
+quiet_cmd_vdsold_and_vdso_check = LD      $@
+      cmd_vdsold_and_vdso_check = $(cmd_ld); $(cmd_vdso_check)
+
 quiet_cmd_vdsomunge = MUNGE   $@
       cmd_vdsomunge = $(objtree)/$(obj)/vdsomunge $< $@
 
diff --git a/arch/arm/vdso/note.c b/arch/arm/vdso/note.c
new file mode 100644
index 000000000000..eff5bf9efb8b
--- /dev/null
+++ b/arch/arm/vdso/note.c
@@ -0,0 +1,15 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2012-2018 ARM Limited
+ *
+ * This supplies .note.* sections to go into the PT_NOTE inside the vDSO text.
+ * Here we can supply some information useful to userland.
+ */
+
+#include <linux/uts.h>
+#include <linux/version.h>
+#include <linux/elfnote.h>
+#include <linux/build-salt.h>
+
+ELFNOTE32("Linux", 0, LINUX_VERSION_CODE);
+BUILD_SALT;
diff --git a/arch/arm/vdso/vgettimeofday.c b/arch/arm/vdso/vgettimeofday.c
index d1fdbb12760a..e64deb75178e 100644
--- a/arch/arm/vdso/vgettimeofday.c
+++ b/arch/arm/vdso/vgettimeofday.c
@@ -1,259 +1,22 @@
 // SPDX-License-Identifier: GPL-2.0-only
 /*
+ * ARM userspace implementations of gettimeofday() and similar.
+ *
  * Copyright 2015 Mentor Graphics Corporation.
  */
-
-#include <linux/compiler.h>
-#include <linux/hrtimer.h>
 #include <linux/time.h>
-#include <asm/barrier.h>
-#include <asm/bug.h>
-#include <asm/cp15.h>
-#include <asm/page.h>
-#include <asm/unistd.h>
-#include <asm/vdso_datapage.h>
-
-#ifndef CONFIG_AEABI
-#error This code depends on AEABI system call conventions
-#endif
-
-extern struct vdso_data *__get_datapage(void);
-
-static notrace u32 __vdso_read_begin(const struct vdso_data *vdata)
-{
-	u32 seq;
-repeat:
-	seq = READ_ONCE(vdata->seq_count);
-	if (seq & 1) {
-		cpu_relax();
-		goto repeat;
-	}
-	return seq;
-}
-
-static notrace u32 vdso_read_begin(const struct vdso_data *vdata)
-{
-	u32 seq;
-
-	seq = __vdso_read_begin(vdata);
-
-	smp_rmb(); /* Pairs with smp_wmb in vdso_write_end */
-	return seq;
-}
-
-static notrace int vdso_read_retry(const struct vdso_data *vdata, u32 start)
-{
-	smp_rmb(); /* Pairs with smp_wmb in vdso_write_begin */
-	return vdata->seq_count != start;
-}
-
-static notrace long clock_gettime_fallback(clockid_t _clkid,
-					   struct timespec *_ts)
-{
-	register struct timespec *ts asm("r1") = _ts;
-	register clockid_t clkid asm("r0") = _clkid;
-	register long ret asm ("r0");
-	register long nr asm("r7") = __NR_clock_gettime;
-
-	asm volatile(
-	"	swi #0\n"
-	: "=r" (ret)
-	: "r" (clkid), "r" (ts), "r" (nr)
-	: "memory");
-
-	return ret;
-}
-
-static notrace int do_realtime_coarse(struct timespec *ts,
-				      struct vdso_data *vdata)
-{
-	u32 seq;
+#include <linux/types.h>
 
-	do {
-		seq = vdso_read_begin(vdata);
-
-		ts->tv_sec = vdata->xtime_coarse_sec;
-		ts->tv_nsec = vdata->xtime_coarse_nsec;
-
-	} while (vdso_read_retry(vdata, seq));
-
-	return 0;
-}
-
-static notrace int do_monotonic_coarse(struct timespec *ts,
-				       struct vdso_data *vdata)
+int __vdso_clock_gettime(clockid_t clock,
+			 struct old_timespec32 *ts)
 {
-	struct timespec tomono;
-	u32 seq;
-
-	do {
-		seq = vdso_read_begin(vdata);
-
-		ts->tv_sec = vdata->xtime_coarse_sec;
-		ts->tv_nsec = vdata->xtime_coarse_nsec;
-
-		tomono.tv_sec = vdata->wtm_clock_sec;
-		tomono.tv_nsec = vdata->wtm_clock_nsec;
-
-	} while (vdso_read_retry(vdata, seq));
-
-	ts->tv_sec += tomono.tv_sec;
-	timespec_add_ns(ts, tomono.tv_nsec);
-
-	return 0;
+	return __cvdso_clock_gettime32(clock, ts);
 }
 
-#ifdef CONFIG_ARM_ARCH_TIMER
-
-static notrace u64 get_ns(struct vdso_data *vdata)
-{
-	u64 cycle_delta;
-	u64 cycle_now;
-	u64 nsec;
-
-	isb();
-	cycle_now = read_sysreg(CNTVCT);
-
-	cycle_delta = (cycle_now - vdata->cs_cycle_last) & vdata->cs_mask;
-
-	nsec = (cycle_delta * vdata->cs_mult) + vdata->xtime_clock_snsec;
-	nsec >>= vdata->cs_shift;
-
-	return nsec;
-}
-
-static notrace int do_realtime(struct timespec *ts, struct vdso_data *vdata)
+int __vdso_gettimeofday(struct __kernel_old_timeval *tv,
+			struct timezone *tz)
 {
-	u64 nsecs;
-	u32 seq;
-
-	do {
-		seq = vdso_read_begin(vdata);
-
-		if (!vdata->tk_is_cntvct)
-			return -1;
-
-		ts->tv_sec = vdata->xtime_clock_sec;
-		nsecs = get_ns(vdata);
-
-	} while (vdso_read_retry(vdata, seq));
-
-	ts->tv_nsec = 0;
-	timespec_add_ns(ts, nsecs);
-
-	return 0;
-}
-
-static notrace int do_monotonic(struct timespec *ts, struct vdso_data *vdata)
-{
-	struct timespec tomono;
-	u64 nsecs;
-	u32 seq;
-
-	do {
-		seq = vdso_read_begin(vdata);
-
-		if (!vdata->tk_is_cntvct)
-			return -1;
-
-		ts->tv_sec = vdata->xtime_clock_sec;
-		nsecs = get_ns(vdata);
-
-		tomono.tv_sec = vdata->wtm_clock_sec;
-		tomono.tv_nsec = vdata->wtm_clock_nsec;
-
-	} while (vdso_read_retry(vdata, seq));
-
-	ts->tv_sec += tomono.tv_sec;
-	ts->tv_nsec = 0;
-	timespec_add_ns(ts, nsecs + tomono.tv_nsec);
-
-	return 0;
-}
-
-#else /* CONFIG_ARM_ARCH_TIMER */
-
-static notrace int do_realtime(struct timespec *ts, struct vdso_data *vdata)
-{
-	return -1;
-}
-
-static notrace int do_monotonic(struct timespec *ts, struct vdso_data *vdata)
-{
-	return -1;
-}
-
-#endif /* CONFIG_ARM_ARCH_TIMER */
-
-notrace int __vdso_clock_gettime(clockid_t clkid, struct timespec *ts)
-{
-	struct vdso_data *vdata;
-	int ret = -1;
-
-	vdata = __get_datapage();
-
-	switch (clkid) {
-	case CLOCK_REALTIME_COARSE:
-		ret = do_realtime_coarse(ts, vdata);
-		break;
-	case CLOCK_MONOTONIC_COARSE:
-		ret = do_monotonic_coarse(ts, vdata);
-		break;
-	case CLOCK_REALTIME:
-		ret = do_realtime(ts, vdata);
-		break;
-	case CLOCK_MONOTONIC:
-		ret = do_monotonic(ts, vdata);
-		break;
-	default:
-		break;
-	}
-
-	if (ret)
-		ret = clock_gettime_fallback(clkid, ts);
-
-	return ret;
-}
-
-static notrace long gettimeofday_fallback(struct timeval *_tv,
-					  struct timezone *_tz)
-{
-	register struct timezone *tz asm("r1") = _tz;
-	register struct timeval *tv asm("r0") = _tv;
-	register long ret asm ("r0");
-	register long nr asm("r7") = __NR_gettimeofday;
-
-	asm volatile(
-	"	swi #0\n"
-	: "=r" (ret)
-	: "r" (tv), "r" (tz), "r" (nr)
-	: "memory");
-
-	return ret;
-}
-
-notrace int __vdso_gettimeofday(struct timeval *tv, struct timezone *tz)
-{
-	struct timespec ts;
-	struct vdso_data *vdata;
-	int ret;
-
-	vdata = __get_datapage();
-
-	ret = do_realtime(&ts, vdata);
-	if (ret)
-		return gettimeofday_fallback(tv, tz);
-
-	if (tv) {
-		tv->tv_sec = ts.tv_sec;
-		tv->tv_usec = ts.tv_nsec / 1000;
-	}
-	if (tz) {
-		tz->tz_minuteswest = vdata->tz_minuteswest;
-		tz->tz_dsttime = vdata->tz_dsttime;
-	}
-
-	return ret;
+	return __cvdso_gettimeofday(tv, tz);
 }
 
 /* Avoid unresolved references emitted by GCC */
-- 
2.23.0


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

[PATCH 2/3] arm: Add clock_getres entry point

[Vincenzo Frascino]

The generic vDSO library provides an implementation of clock_getres() that
can be leveraged by each architecture.

Add clock_getres() entry point on arm to be on pair with arm64.

Cc: Russell King <linux@armlinux.org.uk>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
---
 arch/arm/include/asm/vdso/gettimeofday.h | 20 ++++++++++++++++++++
 arch/arm/vdso/vdso.lds.S                 |  1 +
 arch/arm/vdso/vgettimeofday.c            |  6 ++++++
 3 files changed, 27 insertions(+)

diff --git a/arch/arm/include/asm/vdso/gettimeofday.h b/arch/arm/include/asm/vdso/gettimeofday.h
index 30ce4e87dffc..5b879ae7afc1 100644
--- a/arch/arm/include/asm/vdso/gettimeofday.h
+++ b/arch/arm/include/asm/vdso/gettimeofday.h
@@ -12,6 +12,8 @@
 #include <asm/unistd.h>
 #include <uapi/linux/time.h>
 
+#define VDSO_HAS_CLOCK_GETRES		1
+
 extern struct vdso_data *__get_datapage(void);
 
 static __always_inline int gettimeofday_fallback(
@@ -50,6 +52,24 @@ static __always_inline long clock_gettime_fallback(
 	return ret;
 }
 
+static __always_inline int clock_getres_fallback(
+					clockid_t _clkid,
+					struct __kernel_timespec *_ts)
+{
+	register struct __kernel_timespec *ts asm("r1") = _ts;
+	register clockid_t clkid asm("r0") = _clkid;
+	register long ret asm ("r0");
+	register long nr asm("r7") = __NR_clock_getres_time64;
+
+	asm volatile(
+	"       swi #0\n"
+	: "=r" (ret)
+	: "r" (clkid), "r" (ts), "r" (nr)
+	: "memory");
+
+	return ret;
+}
+
 static __always_inline u64 __arch_get_hw_counter(int clock_mode)
 {
 #ifdef CONFIG_ARM_ARCH_TIMER
diff --git a/arch/arm/vdso/vdso.lds.S b/arch/arm/vdso/vdso.lds.S
index 73cf205b003e..38cb8b0aa3b9 100644
--- a/arch/arm/vdso/vdso.lds.S
+++ b/arch/arm/vdso/vdso.lds.S
@@ -71,6 +71,7 @@ VERSION
 	global:
 		__vdso_clock_gettime;
 		__vdso_gettimeofday;
+		__vdso_clock_getres;
 	local: *;
 	};
 }
diff --git a/arch/arm/vdso/vgettimeofday.c b/arch/arm/vdso/vgettimeofday.c
index e64deb75178e..f6da91f9ccc7 100644
--- a/arch/arm/vdso/vgettimeofday.c
+++ b/arch/arm/vdso/vgettimeofday.c
@@ -19,6 +19,12 @@ int __vdso_gettimeofday(struct __kernel_old_timeval *tv,
 	return __cvdso_gettimeofday(tv, tz);
 }
 
+int __vdso_clock_getres(clockid_t clock_id,
+			struct old_timespec32 *res)
+{
+	return __cvdso_clock_getres_time32(clock_id, res);
+}
+
 /* Avoid unresolved references emitted by GCC */
 
 void __aeabi_unwind_cpp_pr0(void)
-- 
2.23.0


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

[PATCH 3/3] arm: Add clock_gettime64 entry point

[Vincenzo Frascino]

With the release of Linux 5.1 has been added a new syscall,
clock_gettime64, that provided a 64 bit time value for a specified
clock_ID to make the kernel Y2038 safe on 32 bit architectures.

Update the arm specific vDSO library accordingly with what it has
been done for the kernel syscall exposing the clock_gettime64 entry
point.

Cc: Russell King <linux@armlinux.org.uk>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
---
 arch/arm/vdso/vdso.lds.S      | 1 +
 arch/arm/vdso/vgettimeofday.c | 6 ++++++
 2 files changed, 7 insertions(+)

diff --git a/arch/arm/vdso/vdso.lds.S b/arch/arm/vdso/vdso.lds.S
index 38cb8b0aa3b9..165d1d2eb76b 100644
--- a/arch/arm/vdso/vdso.lds.S
+++ b/arch/arm/vdso/vdso.lds.S
@@ -72,6 +72,7 @@ VERSION
 		__vdso_clock_gettime;
 		__vdso_gettimeofday;
 		__vdso_clock_getres;
+		__vdso_clock_gettime64;
 	local: *;
 	};
 }
diff --git a/arch/arm/vdso/vgettimeofday.c b/arch/arm/vdso/vgettimeofday.c
index f6da91f9ccc7..1976c6f325a4 100644
--- a/arch/arm/vdso/vgettimeofday.c
+++ b/arch/arm/vdso/vgettimeofday.c
@@ -13,6 +13,12 @@ int __vdso_clock_gettime(clockid_t clock,
 	return __cvdso_clock_gettime32(clock, ts);
 }
 
+int __vdso_clock_gettime64(clockid_t clock,
+			   struct __kernel_timespec *ts)
+{
+	return __cvdso_clock_gettime(clock, ts);
+}
+
 int __vdso_gettimeofday(struct __kernel_old_timeval *tv,
 			struct timezone *tz)
 {
-- 
2.23.0


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