diff options
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/sched.h | 134 | ||||
| -rw-r--r-- | include/linux/syscalls.h | 4 |
2 files changed, 137 insertions, 1 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h index 14e4f9c12337..3aa4fcb74e76 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -27,6 +27,7 @@ #include <linux/signal_types.h> #include <linux/mm_types_task.h> #include <linux/task_io_accounting.h> +#include <linux/rseq.h> /* task_struct member predeclarations (sorted alphabetically): */ struct audit_context; @@ -1047,6 +1048,17 @@ struct task_struct { unsigned long numa_pages_migrated; #endif /* CONFIG_NUMA_BALANCING */ +#ifdef CONFIG_RSEQ + struct rseq __user *rseq; + u32 rseq_len; + u32 rseq_sig; + /* + * RmW on rseq_event_mask must be performed atomically + * with respect to preemption. + */ + unsigned long rseq_event_mask; +#endif + struct tlbflush_unmap_batch tlb_ubc; struct rcu_head rcu; @@ -1757,4 +1769,126 @@ extern long sched_getaffinity(pid_t pid, struct cpumask *mask); #define TASK_SIZE_OF(tsk) TASK_SIZE #endif +#ifdef CONFIG_RSEQ + +/* + * Map the event mask on the user-space ABI enum rseq_cs_flags + * for direct mask checks. + */ +enum rseq_event_mask_bits { + RSEQ_EVENT_PREEMPT_BIT = RSEQ_CS_FLAG_NO_RESTART_ON_PREEMPT_BIT, + RSEQ_EVENT_SIGNAL_BIT = RSEQ_CS_FLAG_NO_RESTART_ON_SIGNAL_BIT, + RSEQ_EVENT_MIGRATE_BIT = RSEQ_CS_FLAG_NO_RESTART_ON_MIGRATE_BIT, +}; + +enum rseq_event_mask { + RSEQ_EVENT_PREEMPT = (1U << RSEQ_EVENT_PREEMPT_BIT), + RSEQ_EVENT_SIGNAL = (1U << RSEQ_EVENT_SIGNAL_BIT), + RSEQ_EVENT_MIGRATE = (1U << RSEQ_EVENT_MIGRATE_BIT), +}; + +static inline void rseq_set_notify_resume(struct task_struct *t) +{ + if (t->rseq) + set_tsk_thread_flag(t, TIF_NOTIFY_RESUME); +} + +void __rseq_handle_notify_resume(struct pt_regs *regs); + +static inline void rseq_handle_notify_resume(struct pt_regs *regs) +{ + if (current->rseq) + __rseq_handle_notify_resume(regs); +} + +static inline void rseq_signal_deliver(struct pt_regs *regs) +{ + preempt_disable(); + __set_bit(RSEQ_EVENT_SIGNAL_BIT, ¤t->rseq_event_mask); + preempt_enable(); + rseq_handle_notify_resume(regs); +} + +/* rseq_preempt() requires preemption to be disabled. */ +static inline void rseq_preempt(struct task_struct *t) +{ + __set_bit(RSEQ_EVENT_PREEMPT_BIT, &t->rseq_event_mask); + rseq_set_notify_resume(t); +} + +/* rseq_migrate() requires preemption to be disabled. */ +static inline void rseq_migrate(struct task_struct *t) +{ + __set_bit(RSEQ_EVENT_MIGRATE_BIT, &t->rseq_event_mask); + rseq_set_notify_resume(t); +} + +/* + * If parent process has a registered restartable sequences area, the + * child inherits. Only applies when forking a process, not a thread. In + * case a parent fork() in the middle of a restartable sequence, set the + * resume notifier to force the child to retry. + */ +static inline void rseq_fork(struct task_struct *t, unsigned long clone_flags) +{ + if (clone_flags & CLONE_THREAD) { + t->rseq = NULL; + t->rseq_len = 0; + t->rseq_sig = 0; + t->rseq_event_mask = 0; + } else { + t->rseq = current->rseq; + t->rseq_len = current->rseq_len; + t->rseq_sig = current->rseq_sig; + t->rseq_event_mask = current->rseq_event_mask; + rseq_preempt(t); + } +} + +static inline void rseq_execve(struct task_struct *t) +{ + t->rseq = NULL; + t->rseq_len = 0; + t->rseq_sig = 0; + t->rseq_event_mask = 0; +} + +#else + +static inline void rseq_set_notify_resume(struct task_struct *t) +{ +} +static inline void rseq_handle_notify_resume(struct pt_regs *regs) +{ +} +static inline void rseq_signal_deliver(struct pt_regs *regs) +{ +} +static inline void rseq_preempt(struct task_struct *t) +{ +} +static inline void rseq_migrate(struct task_struct *t) +{ +} +static inline void rseq_fork(struct task_struct *t, unsigned long clone_flags) +{ +} +static inline void rseq_execve(struct task_struct *t) +{ +} + +#endif + +#ifdef CONFIG_DEBUG_RSEQ + +void rseq_syscall(struct pt_regs *regs); + +#else + +static inline void rseq_syscall(struct pt_regs *regs) +{ +} + +#endif + #endif diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index 390e814fdc8d..73810808cdf2 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -66,6 +66,7 @@ struct old_linux_dirent; struct perf_event_attr; struct file_handle; struct sigaltstack; +struct rseq; union bpf_attr; #include <linux/types.h> @@ -897,7 +898,8 @@ asmlinkage long sys_pkey_alloc(unsigned long flags, unsigned long init_val); asmlinkage long sys_pkey_free(int pkey); asmlinkage long sys_statx(int dfd, const char __user *path, unsigned flags, unsigned mask, struct statx __user *buffer); - +asmlinkage long sys_rseq(struct rseq __user *rseq, uint32_t rseq_len, + int flags, uint32_t sig); /* * Architecture-specific system calls |