Considering that we explicitly forbid system calls in rseq critical sections, it is not valid to issue a fork or clone system call within a rseq critical section, so rseq_fork() is not required to restart an active rseq c.s. in the child process.
Signed-off-by: Mathieu Desnoyers <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Joel Fernandes <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Catalin Marinas <[email protected]> Cc: Dave Watson <[email protected]> Cc: Will Deacon <[email protected]> Cc: Shuah Khan <[email protected]> Cc: Andi Kleen <[email protected]> Cc: [email protected] Cc: "H . Peter Anvin" <[email protected]> Cc: Chris Lameter <[email protected]> Cc: Russell King <[email protected]> Cc: Michael Kerrisk <[email protected]> Cc: "Paul E . McKenney" <[email protected]> Cc: Paul Turner <[email protected]> Cc: Boqun Feng <[email protected]> Cc: Josh Triplett <[email protected]> Cc: Steven Rostedt <[email protected]> Cc: Ben Maurer <[email protected]> Cc: [email protected] Cc: Andy Lutomirski <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Linus Torvalds <[email protected]> --- include/linux/sched.h | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) diff --git a/include/linux/sched.h b/include/linux/sched.h index 87bf02d93a27..c1882643d455 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1831,9 +1831,7 @@ static inline void rseq_migrate(struct task_struct *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. + * child inherits. Only applies when forking a process, not a thread. */ static inline void rseq_fork(struct task_struct *t, unsigned long clone_flags) { @@ -1847,7 +1845,6 @@ static inline void rseq_fork(struct task_struct *t, unsigned long clone_flags) t->rseq_len = current->rseq_len; t->rseq_sig = current->rseq_sig; t->rseq_event_mask = current->rseq_event_mask; - rseq_preempt(t); } } -- 2.11.0
