[PATCH 1/1] posix clocks: introduce syscall for clock tuning.
From: Richard Cochran
Date: Mon Aug 23 2010 - 04:16:26 EST
A new syscall is introduced that allows tuning of a POSIX clock. The
syscall is implemented for four architectures: arm, blackfin, powerpc,
and x86.
The new syscall, clock_adjtime, takes two parameters, a frequency
adjustment in parts per billion, and a pointer to a struct timespec
containing the clock offset. If the pointer is NULL, a frequency
adjustment is performed. Otherwise, the clock offset is immediately
corrected by skipping to the new time value.
In addtion, the patch provides way to unregister a posix clock. This
function is need to support posix clocks implemented as modules.
Signed-off-by: Richard Cochran <richard.cochran@xxxxxxxxxx>
---
arch/arm/include/asm/unistd.h | 1 +
arch/arm/kernel/calls.S | 1 +
arch/blackfin/include/asm/unistd.h | 3 +-
arch/blackfin/mach-common/entry.S | 1 +
arch/powerpc/include/asm/systbl.h | 1 +
arch/powerpc/include/asm/unistd.h | 3 +-
arch/x86/ia32/ia32entry.S | 1 +
arch/x86/include/asm/unistd_32.h | 3 +-
arch/x86/include/asm/unistd_64.h | 2 +
arch/x86/kernel/syscall_table_32.S | 1 +
include/linux/posix-timers.h | 5 ++++
include/linux/syscalls.h | 3 ++
kernel/compat.c | 20 ++++++++++++++++++
kernel/posix-cpu-timers.c | 5 ++++
kernel/posix-timers.c | 38 ++++++++++++++++++++++++++++++++++++
15 files changed, 85 insertions(+), 3 deletions(-)
diff --git a/arch/arm/include/asm/unistd.h b/arch/arm/include/asm/unistd.h
index dd2bf53..6bea0b7 100644
--- a/arch/arm/include/asm/unistd.h
+++ b/arch/arm/include/asm/unistd.h
@@ -392,6 +392,7 @@
#define __NR_rt_tgsigqueueinfo (__NR_SYSCALL_BASE+363)
#define __NR_perf_event_open (__NR_SYSCALL_BASE+364)
#define __NR_recvmmsg (__NR_SYSCALL_BASE+365)
+#define __NR_clock_adjtime (__NR_SYSCALL_BASE+366)
/*
* The following SWIs are ARM private.
diff --git a/arch/arm/kernel/calls.S b/arch/arm/kernel/calls.S
index 37ae301..8a22fdd 100644
--- a/arch/arm/kernel/calls.S
+++ b/arch/arm/kernel/calls.S
@@ -375,6 +375,7 @@
CALL(sys_rt_tgsigqueueinfo)
CALL(sys_perf_event_open)
/* 365 */ CALL(sys_recvmmsg)
+ CALL(sys_clock_adjtime)
#ifndef syscalls_counted
.equ syscalls_padding, ((NR_syscalls + 3) & ~3) - NR_syscalls
#define syscalls_counted
diff --git a/arch/blackfin/include/asm/unistd.h b/arch/blackfin/include/asm/unistd.h
index 22886cb..6671913 100644
--- a/arch/blackfin/include/asm/unistd.h
+++ b/arch/blackfin/include/asm/unistd.h
@@ -389,8 +389,9 @@
#define __NR_rt_tgsigqueueinfo 368
#define __NR_perf_event_open 369
#define __NR_recvmmsg 370
+#define __NR_clock_adjtime 371
-#define __NR_syscall 371
+#define __NR_syscall 372
#define NR_syscalls __NR_syscall
/* Old optional stuff no one actually uses */
diff --git a/arch/blackfin/mach-common/entry.S b/arch/blackfin/mach-common/entry.S
index a5847f5..252f2fa 100644
--- a/arch/blackfin/mach-common/entry.S
+++ b/arch/blackfin/mach-common/entry.S
@@ -1628,6 +1628,7 @@ ENTRY(_sys_call_table)
.long _sys_rt_tgsigqueueinfo
.long _sys_perf_event_open
.long _sys_recvmmsg /* 370 */
+ .long _sys_clock_adjtime
.rept NR_syscalls-(.-_sys_call_table)/4
.long _sys_ni_syscall
diff --git a/arch/powerpc/include/asm/systbl.h b/arch/powerpc/include/asm/systbl.h
index a5ee345..e7dce86 100644
--- a/arch/powerpc/include/asm/systbl.h
+++ b/arch/powerpc/include/asm/systbl.h
@@ -326,3 +326,4 @@ SYSCALL_SPU(perf_event_open)
COMPAT_SYS_SPU(preadv)
COMPAT_SYS_SPU(pwritev)
COMPAT_SYS(rt_tgsigqueueinfo)
+COMPAT_SYS_SPU(clock_adjtime)
diff --git a/arch/powerpc/include/asm/unistd.h b/arch/powerpc/include/asm/unistd.h
index f0a1026..7d4d9c8 100644
--- a/arch/powerpc/include/asm/unistd.h
+++ b/arch/powerpc/include/asm/unistd.h
@@ -345,10 +345,11 @@
#define __NR_preadv 320
#define __NR_pwritev 321
#define __NR_rt_tgsigqueueinfo 322
+#define __NR_clock_adjtime 323
#ifdef __KERNEL__
-#define __NR_syscalls 323
+#define __NR_syscalls 324
#define __NR__exit __NR_exit
#define NR_syscalls __NR_syscalls
diff --git a/arch/x86/ia32/ia32entry.S b/arch/x86/ia32/ia32entry.S
index e790bc1..8237c8d 100644
--- a/arch/x86/ia32/ia32entry.S
+++ b/arch/x86/ia32/ia32entry.S
@@ -842,4 +842,5 @@ ia32_sys_call_table:
.quad compat_sys_rt_tgsigqueueinfo /* 335 */
.quad sys_perf_event_open
.quad compat_sys_recvmmsg
+ .quad compat_sys_clock_adjtime
ia32_syscall_end:
diff --git a/arch/x86/include/asm/unistd_32.h b/arch/x86/include/asm/unistd_32.h
index beb9b5f..79cbef6 100644
--- a/arch/x86/include/asm/unistd_32.h
+++ b/arch/x86/include/asm/unistd_32.h
@@ -343,10 +343,11 @@
#define __NR_rt_tgsigqueueinfo 335
#define __NR_perf_event_open 336
#define __NR_recvmmsg 337
+#define __NR_clock_adjtime 338
#ifdef __KERNEL__
-#define NR_syscalls 338
+#define NR_syscalls 339
#define __ARCH_WANT_IPC_PARSE_VERSION
#define __ARCH_WANT_OLD_READDIR
diff --git a/arch/x86/include/asm/unistd_64.h b/arch/x86/include/asm/unistd_64.h
index ff4307b..3ee70cd 100644
--- a/arch/x86/include/asm/unistd_64.h
+++ b/arch/x86/include/asm/unistd_64.h
@@ -663,6 +663,8 @@ __SYSCALL(__NR_rt_tgsigqueueinfo, sys_rt_tgsigqueueinfo)
__SYSCALL(__NR_perf_event_open, sys_perf_event_open)
#define __NR_recvmmsg 299
__SYSCALL(__NR_recvmmsg, sys_recvmmsg)
+#define __NR_clock_adjtime 300
+__SYSCALL(__NR_clock_adjtime, sys_clock_adjtime)
#ifndef __NO_STUBS
#define __ARCH_WANT_OLD_READDIR
diff --git a/arch/x86/kernel/syscall_table_32.S b/arch/x86/kernel/syscall_table_32.S
index 8b37293..3569859 100644
--- a/arch/x86/kernel/syscall_table_32.S
+++ b/arch/x86/kernel/syscall_table_32.S
@@ -337,3 +337,4 @@ ENTRY(sys_call_table)
.long sys_rt_tgsigqueueinfo /* 335 */
.long sys_perf_event_open
.long sys_recvmmsg
+ .long sys_clock_adjtime
diff --git a/include/linux/posix-timers.h b/include/linux/posix-timers.h
index 4f71bf4..534c12d 100644
--- a/include/linux/posix-timers.h
+++ b/include/linux/posix-timers.h
@@ -71,6 +71,8 @@ struct k_clock {
int (*clock_getres) (const clockid_t which_clock, struct timespec *tp);
int (*clock_set) (const clockid_t which_clock, struct timespec * tp);
int (*clock_get) (const clockid_t which_clock, struct timespec * tp);
+ int (*clock_adj) (const clockid_t which_clock, int ppb,
+ struct timespec *tp);
int (*timer_create) (struct k_itimer *timer);
int (*nsleep) (const clockid_t which_clock, int flags,
struct timespec *, struct timespec __user *);
@@ -85,6 +87,7 @@ struct k_clock {
};
void register_posix_clock(const clockid_t clock_id, struct k_clock *new_clock);
+void unregister_posix_clock(const clockid_t clock_id);
/* error handlers for timer_create, nanosleep and settime */
int do_posix_clock_nonanosleep(const clockid_t, int flags, struct timespec *,
@@ -97,6 +100,8 @@ int posix_timer_event(struct k_itimer *timr, int si_private);
int posix_cpu_clock_getres(const clockid_t which_clock, struct timespec *ts);
int posix_cpu_clock_get(const clockid_t which_clock, struct timespec *ts);
int posix_cpu_clock_set(const clockid_t which_clock, const struct timespec *ts);
+int posix_cpu_clock_adj(const clockid_t which_clock, int ppb,
+ struct timespec *tp);
int posix_cpu_timer_create(struct k_itimer *timer);
int posix_cpu_nsleep(const clockid_t which_clock, int flags,
struct timespec *rqtp, struct timespec __user *rmtp);
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index 13ebb54..f641cc5 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -314,6 +314,9 @@ asmlinkage long sys_clock_settime(clockid_t which_clock,
const struct timespec __user *tp);
asmlinkage long sys_clock_gettime(clockid_t which_clock,
struct timespec __user *tp);
+asmlinkage long sys_clock_adjtime(clockid_t which_clock,
+ int ppb,
+ const struct timespec __user *tp);
asmlinkage long sys_clock_getres(clockid_t which_clock,
struct timespec __user *tp);
asmlinkage long sys_clock_nanosleep(clockid_t which_clock, int flags,
diff --git a/kernel/compat.c b/kernel/compat.c
index 5adab05..df1e469 100644
--- a/kernel/compat.c
+++ b/kernel/compat.c
@@ -628,6 +628,26 @@ long compat_sys_clock_gettime(clockid_t which_clock,
return err;
}
+long compat_sys_clock_adjtime(clockid_t which_clock, int ppb,
+ struct compat_timespec __user *tp)
+{
+ long err;
+ mm_segment_t oldfs;
+ struct timespec ts, *ptr = NULL;
+
+ if (tp) {
+ if (get_compat_timespec(&ts, tp))
+ return -EFAULT;
+ ptr = &ts;
+ }
+ oldfs = get_fs();
+ set_fs(KERNEL_DS);
+ err = sys_clock_adjtime(which_clock, ppb,
+ (struct timespec __user *) ptr);
+ set_fs(oldfs);
+ return err;
+}
+
long compat_sys_clock_getres(clockid_t which_clock,
struct compat_timespec __user *tp)
{
diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c
index 9829646..5843f5a 100644
--- a/kernel/posix-cpu-timers.c
+++ b/kernel/posix-cpu-timers.c
@@ -207,6 +207,11 @@ int posix_cpu_clock_set(const clockid_t which_clock, const struct timespec *tp)
return error;
}
+int posix_cpu_clock_adj(const clockid_t which_clock, int ppb,
+ struct timespec *tp)
+{
+ return -EOPNOTSUPP;
+}
/*
* Sample a per-thread clock for the given task.
diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c
index ad72342..089b0d1 100644
--- a/kernel/posix-timers.c
+++ b/kernel/posix-timers.c
@@ -197,6 +197,12 @@ static int common_timer_create(struct k_itimer *new_timer)
return 0;
}
+static inline int common_clock_adj(const clockid_t which_clock, int ppb,
+ struct timespec *tp)
+{
+ return -EOPNOTSUPP;
+}
+
static int no_timer_create(struct k_itimer *new_timer)
{
return -EOPNOTSUPP;
@@ -488,6 +494,21 @@ void register_posix_clock(const clockid_t clock_id, struct k_clock *new_clock)
}
EXPORT_SYMBOL_GPL(register_posix_clock);
+void unregister_posix_clock(const clockid_t clock_id)
+{
+ struct k_clock *clock;
+
+ if ((unsigned) clock_id >= MAX_CLOCKS) {
+ pr_err("POSIX clock unregister failed for clock_id %d\n",
+ clock_id);
+ return;
+ }
+
+ clock = &posix_clocks[clock_id];
+ memset(clock, 0, sizeof(*clock));
+}
+EXPORT_SYMBOL_GPL(unregister_posix_clock);
+
static struct k_itimer * alloc_posix_timer(void)
{
struct k_itimer *tmr;
@@ -968,6 +989,23 @@ SYSCALL_DEFINE2(clock_gettime, const clockid_t, which_clock,
}
+SYSCALL_DEFINE3(clock_adjtime, const clockid_t, which_clock,
+ int, ppb, const struct timespec __user *, tp)
+{
+ struct timespec new_tp, *ts = NULL;
+
+ if (invalid_clockid(which_clock))
+ return -EINVAL;
+
+ if (tp) {
+ if (copy_from_user(&new_tp, tp, sizeof(*tp)))
+ return -EFAULT;
+ ts = &new_tp;
+ }
+
+ return CLOCK_DISPATCH(which_clock, clock_adj, (which_clock, ppb, ts));
+}
+
SYSCALL_DEFINE2(clock_getres, const clockid_t, which_clock,
struct timespec __user *, tp)
{
--
1.7.0.4
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