The following commit has been merged into the x86/urgent branch of tip:

Commit-ID: 5abbe51a526253b9f003e9a0a195638dc882d660 Gitweb: https://git.kernel.org/tip/5abbe51a526253b9f003e9a0a195638dc882d660 Author: Oleg Nesterov oleg@redhat.com AuthorDate: Mon, 01 Feb 2021 18:46:41 +01:00 Committer: Thomas Gleixner tglx@linutronix.de CommitterDate: Tue, 16 Mar 2021 22:13:10 +01:00

kernel, fs: Introduce and use set_restart_fn() and arch_set_restart_data()

Preparation for fixing get_nr_restart_syscall() on X86 for COMPAT.

Add a new helper which sets restart_block->fn and calls a dummy arch_set_restart_data() helper.

Fixes: 609c19a385c8 ("x86/ptrace: Stop setting TS_COMPAT in ptrace code") Signed-off-by: Oleg Nesterov oleg@redhat.com Signed-off-by: Thomas Gleixner tglx@linutronix.de Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20210201174641.GA17871@redhat.com

--- fs/select.c | 10 ++++------ include/linux/thread_info.h | 13 +++++++++++++ kernel/futex.c | 3 +-- kernel/time/alarmtimer.c | 2 +- kernel/time/hrtimer.c | 2 +- kernel/time/posix-cpu-timers.c | 2 +- 6 files changed, 21 insertions(+), 11 deletions(-)

diff --git a/fs/select.c b/fs/select.c index 37aaa83..945896d 100644 --- a/fs/select.c +++ b/fs/select.c @@ -1055,10 +1055,9 @@ static long do_restart_poll(struct restart_block *restart_block)

ret = do_sys_poll(ufds, nfds, to);

- if (ret == -ERESTARTNOHAND) { - restart_block->fn = do_restart_poll; - ret = -ERESTART_RESTARTBLOCK; - } + if (ret == -ERESTARTNOHAND) + ret = set_restart_fn(restart_block, do_restart_poll); + return ret; }

@@ -1080,7 +1079,6 @@ SYSCALL_DEFINE3(poll, struct pollfd __user *, ufds, unsigned int, nfds, struct restart_block *restart_block;

restart_block = &current->restart_block; - restart_block->fn = do_restart_poll; restart_block->poll.ufds = ufds; restart_block->poll.nfds = nfds;

@@ -1091,7 +1089,7 @@ SYSCALL_DEFINE3(poll, struct pollfd __user *, ufds, unsigned int, nfds, } else restart_block->poll.has_timeout = 0;

- ret = -ERESTART_RESTARTBLOCK; + ret = set_restart_fn(restart_block, do_restart_poll); } return ret; } diff --git a/include/linux/thread_info.h b/include/linux/thread_info.h index 9b2158c..157762d 100644 --- a/include/linux/thread_info.h +++ b/include/linux/thread_info.h @@ -11,6 +11,7 @@ #include <linux/types.h> #include <linux/bug.h> #include <linux/restart_block.h> +#include <linux/errno.h>

#ifdef CONFIG_THREAD_INFO_IN_TASK /* @@ -59,6 +60,18 @@ enum syscall_work_bit {

#ifdef __KERNEL__

+#ifndef arch_set_restart_data +#define arch_set_restart_data(restart) do { } while (0) +#endif + +static inline long set_restart_fn(struct restart_block *restart, + long (*fn)(struct restart_block *)) +{ + restart->fn = fn; + arch_set_restart_data(restart); + return -ERESTART_RESTARTBLOCK; +} + #ifndef THREAD_ALIGN #define THREAD_ALIGN THREAD_SIZE #endif diff --git a/kernel/futex.c b/kernel/futex.c index e68db77..00febd6 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -2728,14 +2728,13 @@ retry: goto out;

restart = &current->restart_block; - restart->fn = futex_wait_restart; restart->futex.uaddr = uaddr; restart->futex.val = val; restart->futex.time = *abs_time; restart->futex.bitset = bitset; restart->futex.flags = flags | FLAGS_HAS_TIMEOUT;

- ret = -ERESTART_RESTARTBLOCK; + ret = set_restart_fn(restart, futex_wait_restart);

out: if (to) { diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c index 98d7a15..4d94e2b 100644 --- a/kernel/time/alarmtimer.c +++ b/kernel/time/alarmtimer.c @@ -854,9 +854,9 @@ static int alarm_timer_nsleep(const clockid_t which_clock, int flags, if (flags == TIMER_ABSTIME) return -ERESTARTNOHAND;

- restart->fn = alarm_timer_nsleep_restart; restart->nanosleep.clockid = type; restart->nanosleep.expires = exp; + set_restart_fn(restart, alarm_timer_nsleep_restart); return ret; }

diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c index 788b9d1..5c9d968 100644 --- a/kernel/time/hrtimer.c +++ b/kernel/time/hrtimer.c @@ -1957,9 +1957,9 @@ long hrtimer_nanosleep(ktime_t rqtp, const enum hrtimer_mode mode, }

restart = &current->restart_block; - restart->fn = hrtimer_nanosleep_restart; restart->nanosleep.clockid = t.timer.base->clockid; restart->nanosleep.expires = hrtimer_get_expires_tv64(&t.timer); + set_restart_fn(restart, hrtimer_nanosleep_restart); out: destroy_hrtimer_on_stack(&t.timer); return ret; diff --git a/kernel/time/posix-cpu-timers.c b/kernel/time/posix-cpu-timers.c index a71758e..9abe152 100644 --- a/kernel/time/posix-cpu-timers.c +++ b/kernel/time/posix-cpu-timers.c @@ -1480,8 +1480,8 @@ static int posix_cpu_nsleep(const clockid_t which_clock, int flags, if (flags & TIMER_ABSTIME) return -ERESTARTNOHAND;

- restart_block->fn = posix_cpu_nsleep_restart; restart_block->nanosleep.clockid = which_clock; + set_restart_fn(restart_block, posix_cpu_nsleep_restart); } return error; }