Among signal generation syscalls, only sigqueue(2) is allowed by POSIX

to fail due to lack of resources to queue siginfo. Add KSI_SIGQ flag
that allows sigqueue_add() to fail while trying to allocate memory for
new siginfo. When the flag is not set, behaviour is the same as for
KSI_TRAP: if memory cannot be allocated, set bit in sq_kill. KSI_TRAP is
kept to preserve KBI.

Add SI_KERNEL si_code, to be used in siginfo.si_code when signal is
generated by kernel. Deliver siginfo when signal is generated by kill(2)
family of syscalls (SI_USER with properly filled si_uid and si_pid), or
by kernel (SI_KERNEL, mostly job control or SIGIO). Since KSI_SIGQ flag
is not set for the ksi, low memory condition cause old behaviour.

Keep psignal(9) KBI intact, but modify it to generate SI_KERNEL
si_code. Pgsignal(9) and gsignal(9) now take ksi explicitely. Add
pksignal(9) that behaves like psignal but takes ksi, and ddb kill
command implemented as pksignal(..., ksi = NULL) to not do allocation
while in debugger.

While there, remove some register specifiers and use ANSI C prototypes.

Reviewed by:	davidxu
MFC after:	1 month

1 files changed, 1 insertions, 1 deletions

diff --git a/sys/ddb/db_command.c b/sys/ddb/db_command.c
index 1e34016..73de0c5 100644
--- a/sys/ddb/db_command.c
+++ b/sys/ddb/db_command.c
@@ -652,7 +652,7 @@ db_kill(dummy1, dummy2, dummy3, dummy4)
 	if (PROC_TRYLOCK(p) == 0)
 		DB_ERROR(("Can't lock process with pid %ld\n", (long) pid));
 	else {
-		psignal(p, sig);
+		pksignal(p, sig, NULL);
 		PROC_UNLOCK(p);
 	}