On 03/19, Andrei Vagin wrote: > > There are a few system calls (pselect, ppoll, etc) which replace a task > sigmask while they are running in a kernel-space > > When a task calls one of these syscalls, the kernel saves a current > sigmask in task->saved_sigmask and sets a syscall sigmask. > > On syscall-exit-stop, ptrace traps a task before restoring the > saved_sigmask, so PTRACE_GETSIGMASK returns the syscall sigmask and > PTRACE_SETSIGMASK does nothing, because its sigmask is replaced by > saved_sigmask, when the task returns to user-space. > > This patch fixes this problem. PTRACE_GET_SIGMASK returns saved_sigmask > is it's set. PTRACE_SETSIGMASK drops the TIF_RESTORE_SIGMASK flag.
Acked-by: Oleg Nesterov <[email protected]>
