diff options
| -rw-r--r-- | include/linux/irq-entry-common.h | 7 | ||||
| -rw-r--r-- | include/linux/resume_user_mode.h | 2 | ||||
| -rw-r--r-- | include/linux/rseq.h | 18 | ||||
| -rw-r--r-- | init/Kconfig | 2 | ||||
| -rw-r--r-- | kernel/entry/common.c | 26 | ||||
| -rw-r--r-- | kernel/rseq.c | 8 |
6 files changed, 41 insertions, 22 deletions
diff --git a/include/linux/irq-entry-common.h b/include/linux/irq-entry-common.h index cb31fb84d7b4..8f5ceeaaaea5 100644 --- a/include/linux/irq-entry-common.h +++ b/include/linux/irq-entry-common.h @@ -197,11 +197,8 @@ static __always_inline void arch_exit_to_user_mode(void) { } */ void arch_do_signal_or_restart(struct pt_regs *regs); -/** - * exit_to_user_mode_loop - do any pending work before leaving to user space - */ -unsigned long exit_to_user_mode_loop(struct pt_regs *regs, - unsigned long ti_work); +/* Handle pending TIF work */ +unsigned long exit_to_user_mode_loop(struct pt_regs *regs, unsigned long ti_work); /** * exit_to_user_mode_prepare - call exit_to_user_mode_loop() if required diff --git a/include/linux/resume_user_mode.h b/include/linux/resume_user_mode.h index dd3bf7da90a8..bf92227c78d0 100644 --- a/include/linux/resume_user_mode.h +++ b/include/linux/resume_user_mode.h @@ -59,7 +59,7 @@ static inline void resume_user_mode_work(struct pt_regs *regs) mem_cgroup_handle_over_high(GFP_KERNEL); blkcg_maybe_throttle_current(); - rseq_handle_notify_resume(regs); + rseq_handle_slowpath(regs); } #endif /* LINUX_RESUME_USER_MODE_H */ diff --git a/include/linux/rseq.h b/include/linux/rseq.h index abfbeb42d1a2..ded4baa34586 100644 --- a/include/linux/rseq.h +++ b/include/linux/rseq.h @@ -7,13 +7,19 @@ #include <uapi/linux/rseq.h> -void __rseq_handle_notify_resume(struct pt_regs *regs); +void __rseq_handle_slowpath(struct pt_regs *regs); -static inline void rseq_handle_notify_resume(struct pt_regs *regs) +/* Invoked from resume_user_mode_work() */ +static inline void rseq_handle_slowpath(struct pt_regs *regs) { - /* '&' is intentional to spare one conditional branch */ - if (current->rseq.event.sched_switch & current->rseq.event.has_rseq) - __rseq_handle_notify_resume(regs); + if (IS_ENABLED(CONFIG_GENERIC_ENTRY)) { + if (current->rseq.event.slowpath) + __rseq_handle_slowpath(regs); + } else { + /* '&' is intentional to spare one conditional branch */ + if (current->rseq.event.sched_switch & current->rseq.event.has_rseq) + __rseq_handle_slowpath(regs); + } } void __rseq_signal_deliver(int sig, struct pt_regs *regs); @@ -152,7 +158,7 @@ static inline void rseq_fork(struct task_struct *t, u64 clone_flags) } #else /* CONFIG_RSEQ */ -static inline void rseq_handle_notify_resume(struct pt_regs *regs) { } +static inline void rseq_handle_slowpath(struct pt_regs *regs) { } static inline void rseq_signal_deliver(struct ksignal *ksig, struct pt_regs *regs) { } static inline void rseq_sched_switch_event(struct task_struct *t) { } static inline void rseq_sched_set_task_cpu(struct task_struct *t, unsigned int cpu) { } diff --git a/init/Kconfig b/init/Kconfig index bde40ab664e2..d1c606ec632e 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1941,7 +1941,7 @@ config RSEQ_DEBUG_DEFAULT_ENABLE config DEBUG_RSEQ default n bool "Enable debugging of rseq() system call" if EXPERT - depends on RSEQ && DEBUG_KERNEL + depends on RSEQ && DEBUG_KERNEL && !GENERIC_ENTRY select RSEQ_DEBUG_DEFAULT_ENABLE help Enable extra debugging checks for the rseq system call. diff --git a/kernel/entry/common.c b/kernel/entry/common.c index 70a16db4cc0a..523a3e758af4 100644 --- a/kernel/entry/common.c +++ b/kernel/entry/common.c @@ -11,13 +11,8 @@ /* Workaround to allow gradual conversion of architecture code */ void __weak arch_do_signal_or_restart(struct pt_regs *regs) { } -/** - * exit_to_user_mode_loop - do any pending work before leaving to user space - * @regs: Pointer to pt_regs on entry stack - * @ti_work: TIF work flags as read by the caller - */ -__always_inline unsigned long exit_to_user_mode_loop(struct pt_regs *regs, - unsigned long ti_work) +static __always_inline unsigned long __exit_to_user_mode_loop(struct pt_regs *regs, + unsigned long ti_work) { /* * Before returning to user space ensure that all pending work @@ -62,6 +57,23 @@ __always_inline unsigned long exit_to_user_mode_loop(struct pt_regs *regs, return ti_work; } +/** + * exit_to_user_mode_loop - do any pending work before leaving to user space + * @regs: Pointer to pt_regs on entry stack + * @ti_work: TIF work flags as read by the caller + */ +__always_inline unsigned long exit_to_user_mode_loop(struct pt_regs *regs, + unsigned long ti_work) +{ + for (;;) { + ti_work = __exit_to_user_mode_loop(regs, ti_work); + + if (likely(!rseq_exit_to_user_mode_restart(regs))) + return ti_work; + ti_work = read_thread_flags(); + } +} + noinstr irqentry_state_t irqentry_enter(struct pt_regs *regs) { irqentry_state_t ret = { diff --git a/kernel/rseq.c b/kernel/rseq.c index c5d6336c6956..395d8b002350 100644 --- a/kernel/rseq.c +++ b/kernel/rseq.c @@ -237,7 +237,11 @@ efault: static void rseq_slowpath_update_usr(struct pt_regs *regs) { - /* Preserve rseq state and user_irq state for exit to user */ + /* + * Preserve rseq state and user_irq state. The generic entry code + * clears user_irq on the way out, the non-generic entry + * architectures are not having user_irq. + */ const struct rseq_event evt_mask = { .has_rseq = true, .user_irq = true, }; struct task_struct *t = current; struct rseq_ids ids; @@ -289,7 +293,7 @@ static void rseq_slowpath_update_usr(struct pt_regs *regs) } } -void __rseq_handle_notify_resume(struct pt_regs *regs) +void __rseq_handle_slowpath(struct pt_regs *regs) { /* * If invoked from hypervisors before entering the guest via |