diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2025-10-27 09:44:26 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2025-11-04 08:30:09 +0100 |
| commit | d923739e2e356424cc566143a3323c62cd6ed067 (patch) | |
| tree | bf852569d2a610de7c98b934374f47665a9a603b /include/uapi | |
| parent | 067b3b41b4dd5bf51d6874206f5c1f72e0684eeb (diff) | |
rseq: Simplify the event notification
Since commit 0190e4198e47 ("rseq: Deprecate RSEQ_CS_FLAG_NO_RESTART_ON_*
flags") the bits in task::rseq_event_mask are meaningless and just extra
work in terms of setting them individually.
Aside of that the only relevant point where an event has to be raised is
context switch. Neither the CPU nor MM CID can change without going through
a context switch.
Collapse them all into a single boolean which simplifies the code a lot and
remove the pointless invocations which have been sprinkled all over the
place for no value.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://patch.msgid.link/20251027084306.336978188@linutronix.de
Diffstat (limited to 'include/uapi')
| -rw-r--r-- | include/uapi/linux/rseq.h | 21 |
1 files changed, 7 insertions, 14 deletions
diff --git a/include/uapi/linux/rseq.h b/include/uapi/linux/rseq.h index c233aae5eac9..1b76d508400c 100644 --- a/include/uapi/linux/rseq.h +++ b/include/uapi/linux/rseq.h @@ -114,20 +114,13 @@ struct rseq { /* * Restartable sequences flags field. * - * This field should only be updated by the thread which - * registered this data structure. Read by the kernel. - * Mainly used for single-stepping through rseq critical sections - * with debuggers. - * - * - RSEQ_CS_FLAG_NO_RESTART_ON_PREEMPT - * Inhibit instruction sequence block restart on preemption - * for this thread. - * - RSEQ_CS_FLAG_NO_RESTART_ON_SIGNAL - * Inhibit instruction sequence block restart on signal - * delivery for this thread. - * - RSEQ_CS_FLAG_NO_RESTART_ON_MIGRATE - * Inhibit instruction sequence block restart on migration for - * this thread. + * This field was initially intended to allow event masking for + * single-stepping through rseq critical sections with debuggers. + * The kernel does not support this anymore and the relevant bits + * are checked for being always false: + * - RSEQ_CS_FLAG_NO_RESTART_ON_PREEMPT + * - RSEQ_CS_FLAG_NO_RESTART_ON_SIGNAL + * - RSEQ_CS_FLAG_NO_RESTART_ON_MIGRATE */ __u32 flags; |