diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2025-10-27 09:45:10 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2025-11-04 08:33:47 +0100 |
| commit | 9f6ffd4cebda86841700775de3213f22bb0ea22d (patch) | |
| tree | b1cd57fb664fa27497894816ac35a8d0796110a7 /include/linux/rseq.h | |
| parent | 0f085b41880e3140efa6941ff2b8fd43bac4d659 (diff) | |
rseq: Separate the signal delivery path
Completely separate the signal delivery path from the notify handler as
they have different semantics versus the event handling.
The signal delivery only needs to ensure that the interrupted user context
was not in a critical section or the section is aborted before it switches
to the signal frame context. The signal frame context does not have the
original instruction pointer anymore, so that can't be handled on exit to
user space.
No point in updating the CPU/CID ids as they might change again before the
task returns to user space for real.
The fast path optimization, which checks for the 'entry from user via
interrupt' condition is only available for architectures which use the
generic entry code.
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/20251027084307.455429038@linutronix.de
Diffstat (limited to 'include/linux/rseq.h')
| -rw-r--r-- | include/linux/rseq.h | 21 |
1 files changed, 16 insertions, 5 deletions
diff --git a/include/linux/rseq.h b/include/linux/rseq.h index 92f9cd49489b..f5a43188023f 100644 --- a/include/linux/rseq.h +++ b/include/linux/rseq.h @@ -7,22 +7,33 @@ #include <uapi/linux/rseq.h> -void __rseq_handle_notify_resume(struct ksignal *sig, struct pt_regs *regs); +void __rseq_handle_notify_resume(struct pt_regs *regs); static inline void rseq_handle_notify_resume(struct pt_regs *regs) { if (current->rseq.event.has_rseq) - __rseq_handle_notify_resume(NULL, regs); + __rseq_handle_notify_resume(regs); } +void __rseq_signal_deliver(int sig, struct pt_regs *regs); + +/* + * Invoked from signal delivery to fixup based on the register context before + * switching to the signal delivery context. + */ static inline void rseq_signal_deliver(struct ksignal *ksig, struct pt_regs *regs) { - if (current->rseq.event.has_rseq) { - current->rseq.event.sched_switch = true; - __rseq_handle_notify_resume(ksig, regs); + if (IS_ENABLED(CONFIG_GENERIC_IRQ_ENTRY)) { + /* '&' is intentional to spare one conditional branch */ + if (current->rseq.event.has_rseq & current->rseq.event.user_irq) + __rseq_signal_deliver(ksig->sig, regs); + } else { + if (current->rseq.event.has_rseq) + __rseq_signal_deliver(ksig->sig, regs); } } +/* Raised from context switch and exevce to force evaluation on exit to user */ static inline void rseq_sched_switch_event(struct task_struct *t) { if (t->rseq.event.has_rseq) { |