[tip: timers/core] posix-timers: Document sys_clock_settime() permissions in place

tip-bot2 for Thomas Gleixner
2023-06-18T20:50:42Z

The following commit has been merged into the timers/core branch of tip:

Commit-ID: 3561fcb402b7ab7fdb4c1746dae4995889506605
Gitweb: https://git.kernel.org/tip/3561fcb402b7ab7fdb4c1746dae4995889506605
Author: Thomas Gleixner <tglx@linutronix.de>
AuthorDate: Tue, 25 Apr 2023 20:49:16 +02:00
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Sun, 18 Jun 2023 22:41:51 +02:00

posix-timers: Document sys_clock_settime() permissions in place

The documentation of sys_clock_settime() permissions is at a random place
and mostly word salad.

Remove it and add a concise comment into sys_clock_settime().

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20230425183313.514700292@linutronix.de

---
kernel/time/posix-timers.c | 11 ++++-------
1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/kernel/time/posix-timers.c b/kernel/time/posix-timers.c
index 191ecf5..03ef6af 100644
--- a/kernel/time/posix-timers.c
+++ b/kernel/time/posix-timers.c
@@ -74,13 +74,6 @@ static const struct k_clock clock_realtime, clock_monotonic;
* following: 1.) The k_itimer struct (sched.h) is used for
* the timer. 2.) The list, it_lock, it_clock, it_id and
* it_pid fields are not modified by timer code.
- *
- * Permissions: It is assumed that the clock_settime() function defined
- * for each clock will take care of permission checks. Some
- * clocks may be set able by any user (i.e. local process
- * clocks) others not. Currently the only set able clock we
- * have is CLOCK_REALTIME and its high res counter part, both of
- * which we beg off on and pass to do_sys_settimeofday().
*/
static struct k_itimer *__lock_timer(timer_t timer_id, unsigned long *flags);

@@ -1159,6 +1152,10 @@ SYSCALL_DEFINE2(clock_settime, const clockid_t, which_clock,
if (get_timespec64(&new_tp, tp))
return -EFAULT;

+ /*
+ * Permission checks have to be done inside the clock specific
+ * setter callback.
+ */
return kc->clock_set(which_clock, &new_tp);
}