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Message-Id: <20170619064515.922-3-deepa.kernel@gmail.com>
Date: Sun, 18 Jun 2017 23:45:09 -0700
From: Deepa Dinamani <deepa.kernel@...il.com>
To: tglx@...utronix.de, viro@...iv.linux.org.uk,
linux-kernel@...r.kernel.org
Cc: john.stultz@...aro.org, nicolas.pitre@...aro.org, arnd@...db.de,
y2038@...ts.linaro.org, linux-fsdevel@...r.kernel.org
Subject: [PATCH 2/8] nanosleep: Move native and compat syscalls
Move nanosleep syscall to a new file that is compiled
unconditionally. This helps share common nanosleep code
between posix-timers and posix-stubs. The latter part
is addressed in subsequent patches in the series.
In this series, this also servers as a preparatory patch
to eliminate the use of set_fs()/get_fs() in the compat
syscall path.
Note that the clock_nanosleep compat syscalls have to be moved
twice, once into each file: posix_timers.c and posix-stubs.c.
Signed-off-by: Deepa Dinamani <deepa.kernel@...il.com>
---
kernel/compat.c | 131 ---------------------------------------------
kernel/time/hrtimer.c | 17 +-----
kernel/time/nanosleep.c | 94 ++++++++++++++++++++++++++++++++
kernel/time/posix-stubs.c | 56 +++++++++++++++++++
kernel/time/posix-timers.c | 58 ++++++++++++++++++++
5 files changed, 209 insertions(+), 147 deletions(-)
create mode 100644 kernel/time/nanosleep.c
diff --git a/kernel/compat.c b/kernel/compat.c
index c7a01a01222d..89d10cf47e9c 100644
--- a/kernel/compat.c
+++ b/kernel/compat.c
@@ -257,82 +257,6 @@ int compat_convert_timespec(struct timespec __user **kts,
return 0;
}
-static long compat_nanosleep_restart(struct restart_block *restart)
-{
- struct compat_timespec __user *rmtp;
- struct timespec rmt;
- mm_segment_t oldfs;
- long ret;
-
- restart->nanosleep.rmtp = (struct timespec __user *) &rmt;
- oldfs = get_fs();
- set_fs(KERNEL_DS);
- ret = hrtimer_nanosleep_restart(restart);
- set_fs(oldfs);
-
- if (ret == -ERESTART_RESTARTBLOCK) {
- rmtp = restart->nanosleep.compat_rmtp;
-
- if (rmtp && compat_put_timespec(&rmt, rmtp))
- return -EFAULT;
- }
-
- return ret;
-}
-
-COMPAT_SYSCALL_DEFINE2(nanosleep, struct compat_timespec __user *, rqtp,
- struct compat_timespec __user *, rmtp)
-{
- struct timespec tu, rmt;
- struct timespec64 tu64;
- mm_segment_t oldfs;
- long ret;
-
- if (compat_get_timespec(&tu, rqtp))
- return -EFAULT;
-
- tu64 = timespec_to_timespec64(tu);
- if (!timespec64_valid(&tu64))
- return -EINVAL;
-
- oldfs = get_fs();
- set_fs(KERNEL_DS);
- ret = hrtimer_nanosleep(&tu64,
- rmtp ? (struct timespec __user *)&rmt : NULL,
- HRTIMER_MODE_REL, CLOCK_MONOTONIC);
- set_fs(oldfs);
-
- /*
- * hrtimer_nanosleep() can only return 0 or
- * -ERESTART_RESTARTBLOCK here because:
- *
- * - we call it with HRTIMER_MODE_REL and therefor exclude the
- * -ERESTARTNOHAND return path.
- *
- * - we supply the rmtp argument from the task stack (due to
- * the necessary compat conversion. So the update cannot
- * fail, which excludes the -EFAULT return path as well. If
- * it fails nevertheless we have a bigger problem and wont
- * reach this place anymore.
- *
- * - if the return value is 0, we do not have to update rmtp
- * because there is no remaining time.
- *
- * We check for -ERESTART_RESTARTBLOCK nevertheless if the
- * core implementation decides to return random nonsense.
- */
- if (ret == -ERESTART_RESTARTBLOCK) {
- struct restart_block *restart = ¤t->restart_block;
-
- restart->fn = compat_nanosleep_restart;
- restart->nanosleep.compat_rmtp = rmtp;
-
- if (rmtp && compat_put_timespec(&rmt, rmtp))
- return -EFAULT;
- }
- return ret;
-}
-
static inline long get_compat_itimerval(struct itimerval *o,
struct compat_itimerval __user *i)
{
@@ -865,61 +789,6 @@ COMPAT_SYSCALL_DEFINE2(clock_getres, clockid_t, which_clock,
return err;
}
-static long compat_clock_nanosleep_restart(struct restart_block *restart)
-{
- long err;
- mm_segment_t oldfs;
- struct timespec tu;
- struct compat_timespec __user *rmtp = restart->nanosleep.compat_rmtp;
-
- restart->nanosleep.rmtp = (struct timespec __user *) &tu;
- oldfs = get_fs();
- set_fs(KERNEL_DS);
- err = clock_nanosleep_restart(restart);
- set_fs(oldfs);
-
- if ((err == -ERESTART_RESTARTBLOCK) && rmtp &&
- compat_put_timespec(&tu, rmtp))
- return -EFAULT;
-
- if (err == -ERESTART_RESTARTBLOCK) {
- restart->fn = compat_clock_nanosleep_restart;
- restart->nanosleep.compat_rmtp = rmtp;
- }
- return err;
-}
-
-COMPAT_SYSCALL_DEFINE4(clock_nanosleep, clockid_t, which_clock, int, flags,
- struct compat_timespec __user *, rqtp,
- struct compat_timespec __user *, rmtp)
-{
- long err;
- mm_segment_t oldfs;
- struct timespec in, out;
- struct restart_block *restart;
-
- if (compat_get_timespec(&in, rqtp))
- return -EFAULT;
-
- oldfs = get_fs();
- set_fs(KERNEL_DS);
- err = sys_clock_nanosleep(which_clock, flags,
- (struct timespec __user *) &in,
- (struct timespec __user *) &out);
- set_fs(oldfs);
-
- if ((err == -ERESTART_RESTARTBLOCK) && rmtp &&
- compat_put_timespec(&out, rmtp))
- return -EFAULT;
-
- if (err == -ERESTART_RESTARTBLOCK) {
- restart = ¤t->restart_block;
- restart->fn = compat_clock_nanosleep_restart;
- restart->nanosleep.compat_rmtp = rmtp;
- }
- return err;
-}
-
/*
* We currently only need the following fields from the sigevent
* structure: sigev_value, sigev_signo, sig_notify and (sometimes
diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c
index ac053bb5296e..e95628910b00 100644
--- a/kernel/time/hrtimer.c
+++ b/kernel/time/hrtimer.c
@@ -37,6 +37,7 @@
#include <linux/hrtimer.h>
#include <linux/notifier.h>
#include <linux/syscalls.h>
+#include <linux/compat.h>
#include <linux/kallsyms.h>
#include <linux/interrupt.h>
#include <linux/tick.h>
@@ -1544,22 +1545,6 @@ long hrtimer_nanosleep(struct timespec64 *rqtp, struct timespec __user *rmtp,
return ret;
}
-SYSCALL_DEFINE2(nanosleep, struct timespec __user *, rqtp,
- struct timespec __user *, rmtp)
-{
- struct timespec64 tu64;
- struct timespec tu;
-
- if (copy_from_user(&tu, rqtp, sizeof(tu)))
- return -EFAULT;
-
- tu64 = timespec_to_timespec64(tu);
- if (!timespec64_valid(&tu64))
- return -EINVAL;
-
- return hrtimer_nanosleep(&tu64, rmtp, HRTIMER_MODE_REL, CLOCK_MONOTONIC);
-}
-
/*
* Functions related to boot-time initialization:
*/
diff --git a/kernel/time/nanosleep.c b/kernel/time/nanosleep.c
new file mode 100644
index 000000000000..2b6e6980b65d
--- /dev/null
+++ b/kernel/time/nanosleep.c
@@ -0,0 +1,94 @@
+SYSCALL_DEFINE2(nanosleep, struct timespec __user *, rqtp,
+ struct timespec __user *, rmtp)
+{
+ struct timespec64 tu64;
+ struct timespec tu;
+
+ if (copy_from_user(&tu, rqtp, sizeof(tu)))
+ return -EFAULT;
+
+ tu64 = timespec_to_timespec64(tu);
+ if (!timespec64_valid(&tu64))
+ return -EINVAL;
+
+ return hrtimer_nanosleep(&tu64, rmtp, HRTIMER_MODE_REL, CLOCK_MONOTONIC);
+}
+
+#ifdef CONFIG_COMPAT
+static long compat_nanosleep_restart(struct restart_block *restart)
+{
+ struct compat_timespec __user *rmtp;
+ struct timespec rmt;
+ mm_segment_t oldfs;
+ long ret;
+
+ restart->nanosleep.rmtp = (struct timespec __user *) &rmt;
+ oldfs = get_fs();
+ set_fs(KERNEL_DS);
+ ret = hrtimer_nanosleep_restart(restart);
+ set_fs(oldfs);
+
+ if (ret == -ERESTART_RESTARTBLOCK) {
+ rmtp = restart->nanosleep.compat_rmtp;
+
+ if (rmtp && compat_put_timespec(&rmt, rmtp))
+ return -EFAULT;
+ }
+
+ return ret;
+}
+
+COMPAT_SYSCALL_DEFINE2(nanosleep, struct compat_timespec __user *, rqtp,
+ struct compat_timespec __user *, rmtp)
+{
+ struct timespec tu, rmt;
+ struct timespec64 tu64;
+ mm_segment_t oldfs;
+ long ret;
+
+ if (compat_get_timespec(&tu, rqtp))
+ return -EFAULT;
+
+ tu64 = timespec_to_timespec64(tu);
+ if (!timespec64_valid(&tu64))
+ return -EINVAL;
+
+ oldfs = get_fs();
+ set_fs(KERNEL_DS);
+ ret = hrtimer_nanosleep(&tu64,
+ rmtp ? (struct timespec __user *)&rmt : NULL,
+ HRTIMER_MODE_REL, CLOCK_MONOTONIC);
+ set_fs(oldfs);
+
+ /*
+ * hrtimer_nanosleep() can only return 0 or
+ * -ERESTART_RESTARTBLOCK here because:
+ *
+ * - we call it with HRTIMER_MODE_REL and therefor exclude the
+ * -ERESTARTNOHAND return path.
+ *
+ * - we supply the rmtp argument from the task stack (due to
+ * the necessary compat conversion. So the update cannot
+ * fail, which excludes the -EFAULT return path as well. If
+ * it fails nevertheless we have a bigger problem and wont
+ * reach this place anymore.
+ *
+ * - if the return value is 0, we do not have to update rmtp
+ * because there is no remaining time.
+ *
+ * We check for -ERESTART_RESTARTBLOCK nevertheless if the
+ * core implementation decides to return random nonsense.
+ */
+ if (ret == -ERESTART_RESTARTBLOCK) {
+ struct restart_block *restart = ¤t->restart_block;
+
+ restart->fn = compat_nanosleep_restart;
+ restart->nanosleep.compat_rmtp = rmtp;
+
+ if (rmtp && compat_put_timespec(&rmt, rmtp))
+ return -EFAULT;
+ }
+ return ret;
+}
+#endif
+
diff --git a/kernel/time/posix-stubs.c b/kernel/time/posix-stubs.c
index c0cd53eb018a..3031a28921ba 100644
--- a/kernel/time/posix-stubs.c
+++ b/kernel/time/posix-stubs.c
@@ -14,6 +14,7 @@
#include <linux/sched.h>
#include <linux/errno.h>
#include <linux/syscalls.h>
+#include <linux/compat.h>
#include <linux/ktime.h>
#include <linux/timekeeping.h>
#include <linux/posix-timers.h>
@@ -128,4 +129,59 @@ long clock_nanosleep_restart(struct restart_block *restart_block)
{
return hrtimer_nanosleep_restart(restart_block);
}
+
+static long compat_clock_nanosleep_restart(struct restart_block *restart)
+{
+ long err;
+ mm_segment_t oldfs;
+ struct timespec tu;
+ struct compat_timespec __user *rmtp = restart->nanosleep.compat_rmtp;
+
+ restart->nanosleep.rmtp = (struct timespec __user *) &tu;
+ oldfs = get_fs();
+ set_fs(KERNEL_DS);
+ err = clock_nanosleep_restart(restart);
+ set_fs(oldfs);
+
+ if ((err == -ERESTART_RESTARTBLOCK) && rmtp &&
+ compat_put_timespec(&tu, rmtp))
+ return -EFAULT;
+
+ if (err == -ERESTART_RESTARTBLOCK) {
+ restart->fn = compat_clock_nanosleep_restart;
+ restart->nanosleep.compat_rmtp = rmtp;
+ }
+ return err;
+}
+
+COMPAT_SYSCALL_DEFINE4(clock_nanosleep, clockid_t, which_clock, int, flags,
+ struct compat_timespec __user *, rqtp,
+ struct compat_timespec __user *, rmtp)
+{
+ long err;
+ mm_segment_t oldfs;
+ struct timespec in, out;
+ struct restart_block *restart;
+
+ if (compat_get_timespec(&in, rqtp))
+ return -EFAULT;
+
+ oldfs = get_fs();
+ set_fs(KERNEL_DS);
+ err = sys_clock_nanosleep(which_clock, flags,
+ (struct timespec __user *) &in,
+ (struct timespec __user *) &out);
+ set_fs(oldfs);
+
+ if ((err == -ERESTART_RESTARTBLOCK) && rmtp &&
+ compat_put_timespec(&out, rmtp))
+ return -EFAULT;
+
+ if (err == -ERESTART_RESTARTBLOCK) {
+ restart = ¤t->restart_block;
+ restart->fn = compat_clock_nanosleep_restart;
+ restart->nanosleep.compat_rmtp = rmtp;
+ }
+ return err;
+}
#endif
diff --git a/kernel/time/posix-timers.c b/kernel/time/posix-timers.c
index 6e7a70b1bf37..cf32adccd062 100644
--- a/kernel/time/posix-timers.c
+++ b/kernel/time/posix-timers.c
@@ -45,6 +45,7 @@
#include <linux/posix-clock.h>
#include <linux/posix-timers.h>
#include <linux/syscalls.h>
+#include <linux/compat.h>
#include <linux/wait.h>
#include <linux/workqueue.h>
#include <linux/export.h>
@@ -1176,3 +1177,60 @@ static const struct k_clock *clockid_to_kclock(const clockid_t id)
return NULL;
return posix_clocks[id];
}
+
+#ifdef CONFIG_COMPAT
+static long compat_clock_nanosleep_restart(struct restart_block *restart)
+{
+ long err;
+ mm_segment_t oldfs;
+ struct timespec tu;
+ struct compat_timespec __user *rmtp = restart->nanosleep.compat_rmtp;
+
+ restart->nanosleep.rmtp = (struct timespec __user *) &tu;
+ oldfs = get_fs();
+ set_fs(KERNEL_DS);
+ err = clock_nanosleep_restart(restart);
+ set_fs(oldfs);
+
+ if ((err == -ERESTART_RESTARTBLOCK) && rmtp &&
+ compat_put_timespec(&tu, rmtp))
+ return -EFAULT;
+
+ if (err == -ERESTART_RESTARTBLOCK) {
+ restart->fn = compat_clock_nanosleep_restart;
+ restart->nanosleep.compat_rmtp = rmtp;
+ }
+ return err;
+}
+
+COMPAT_SYSCALL_DEFINE4(clock_nanosleep, clockid_t, which_clock, int, flags,
+ struct compat_timespec __user *, rqtp,
+ struct compat_timespec __user *, rmtp)
+{
+ long err;
+ mm_segment_t oldfs;
+ struct timespec in, out;
+ struct restart_block *restart;
+
+ if (compat_get_timespec(&in, rqtp))
+ return -EFAULT;
+
+ oldfs = get_fs();
+ set_fs(KERNEL_DS);
+ err = sys_clock_nanosleep(which_clock, flags,
+ (struct timespec __user *) &in,
+ (struct timespec __user *) &out);
+ set_fs(oldfs);
+
+ if ((err == -ERESTART_RESTARTBLOCK) && rmtp &&
+ compat_put_timespec(&out, rmtp))
+ return -EFAULT;
+
+ if (err == -ERESTART_RESTARTBLOCK) {
+ restart = ¤t->restart_block;
+ restart->fn = compat_clock_nanosleep_restart;
+ restart->nanosleep.compat_rmtp = rmtp;
+ }
+ return err;
+}
+#endif
--
2.11.0
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