diff options
| -rw-r--r-- | include/linux/rseq.h | 21 | ||||
| -rw-r--r-- | kernel/rseq.c | 30 |
2 files changed, 38 insertions, 13 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) { diff --git a/kernel/rseq.c b/kernel/rseq.c index 1e4f1d2cdfe5..13faadc737ad 100644 --- a/kernel/rseq.c +++ b/kernel/rseq.c @@ -250,13 +250,12 @@ efault: * respect to other threads scheduled on the same CPU, and with respect * to signal handlers. */ -void __rseq_handle_notify_resume(struct ksignal *ksig, struct pt_regs *regs) +void __rseq_handle_notify_resume(struct pt_regs *regs) { struct task_struct *t = current; struct rseq_ids ids; u32 node_id; bool event; - int sig; /* * If invoked from hypervisors before entering the guest via @@ -275,10 +274,7 @@ void __rseq_handle_notify_resume(struct ksignal *ksig, struct pt_regs *regs) if (unlikely(t->flags & PF_EXITING)) return; - if (ksig) - rseq_stat_inc(rseq_stats.signal); - else - rseq_stat_inc(rseq_stats.slowpath); + rseq_stat_inc(rseq_stats.slowpath); /* * Read and clear the event pending bit first. If the task @@ -317,8 +313,26 @@ void __rseq_handle_notify_resume(struct ksignal *ksig, struct pt_regs *regs) return; error: - sig = ksig ? ksig->sig : 0; - force_sigsegv(sig); + force_sig(SIGSEGV); +} + +void __rseq_signal_deliver(int sig, struct pt_regs *regs) +{ + rseq_stat_inc(rseq_stats.signal); + /* + * Don't update IDs, they are handled on exit to user if + * necessary. The important thing is to abort a critical section of + * the interrupted context as after this point the instruction + * pointer in @regs points to the signal handler. + */ + if (unlikely(!rseq_handle_cs(current, regs))) { + /* + * Clear the errors just in case this might survive + * magically, but leave the rest intact. + */ + current->rseq.event.error = 0; + force_sigsegv(sig); + } } /* |