On 06/26, Ralf Baechle wrote:
>
> On Wed, Jun 26, 2013 at 06:14:52PM +0200, Oleg Nesterov wrote:
>
> > Or simply remove the BUG_ON(), this can equally confuse wait(status).
> > 128 & 0x7f == 0.
> >
> > Still I think it would be better to change _NSIG on mips.
>
> If it was that easy. That's going to outright break binary compatibility,
> see kernel/signal.c:
>
> SYSCALL_DEFINE4(rt_sigprocmask, int, how, sigset_t __user *, nset,
> sigset_t __user *, oset, size_t, sigsetsize)
> {
> sigset_t old_set, new_set;
> int error;
>
> /* XXX: Don't preclude handling different sized sigset_t's. */
> if (sigsetsize != sizeof(sigset_t))
> return -EINVAL;
I meant the minimal hack like
--- x/arch/mips/include/uapi/asm/signal.h
+++ x/arch/mips/include/uapi/asm/signal.h
@@ -11,9 +11,9 @@
#include <linux/types.h>
-#define _NSIG 128
+#define _NSIG 127
#define _NSIG_BPW (sizeof(unsigned long) * 8)
-#define _NSIG_WORDS (_NSIG / _NSIG_BPW)
+#define _NSIG_WORDS DIV_ROUND_UP(_NSIG / _NSIG_BPW)
typedef struct {
unsigned long sig[_NSIG_WORDS];
just to avoid BUG_ON().
I agree that _NSIG == 126 or 64 needs more discussion. Although personally
I think this is the only choice in the long term, or we should change ABI
and break user-space completely.
And, just in case, the hack above doesn't kill SIG_128 completely.
Say, the task can block/unblock it.
Oleg.
