On Mon, Feb 27, 2012 at 11:22 AM, Oleg Nesterov <oleg@xxxxxxxxxx> wrote: > On 02/24, Will Drewry wrote: >> >> To ensure that SIGSYS delivery occurs on return from the triggering >> system call, SIGSYS is added to the SYNCHRONOUS_MASK macro. > > Hmm. Can't understand... please help. > >> #define SYNCHRONOUS_MASK \ >> (sigmask(SIGSEGV) | sigmask(SIGBUS) | sigmask(SIGILL) | \ >> - sigmask(SIGTRAP) | sigmask(SIGFPE)) >> + sigmask(SIGTRAP) | sigmask(SIGFPE) | sigmask(SIGSYS)) > > Why? > > SYNCHRONOUS_MASK just tells dequeue_signal() "pick them first". > This is needed to make sure that the handler for, say SIGSEGV, > can use ucontext->ip as a faulting addr. I think that Roland covered this. (Since the syscall_rollback was called it's nice to let our handler get first go.) > But seccomp adds info->si_call_addr, this looks unneeded. True enough. I can drop it. It'd only be useful if the SIGSYS wasn't being forced and the signal was being handled without ucontext_t access. thanks! -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
