Allow SIGKILL to terminate coredumping processes. Semantics decided

with kettenis guenther and beck.
ok guenther

3 files changed, 23 insertions, 8 deletions

diff --git a/sys/kern/kern_sig.c b/sys/kern/kern_sig.c
index 0820b9c0501..a817906af65 100644
--- a/sys/kern/kern_sig.c
+++ b/sys/kern/kern_sig.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kern_sig.c,v 1.146 2013/01/15 01:34:27 deraadt Exp $	*/
+/*	$OpenBSD: kern_sig.c,v 1.147 2013/01/15 02:03:38 deraadt Exp $	*/
 /*	$NetBSD: kern_sig.c,v 1.54 1996/04/22 01:38:32 christos Exp $	*/
 
 /*
@@ -803,6 +803,14 @@ ptsignal(struct proc *p, int signum, enum signal_type type)
 	mask = sigmask(signum);
 
 	if (type == SPROCESS) {
+		/* Accept SIGKILL to coredumping processes */
+		if (pr->ps_flags & PS_COREDUMP && signum == SIGKILL) {
+			if (pr->ps_single != NULL)
+				p = pr->ps_single;
+			atomic_setbits_int(&p->p_siglist, mask);
+			return;
+		}
+
 		/*
 		 * A process-wide signal can be diverted to a different
 		 * thread that's in sigwait() for this signal.  If there
@@ -1414,6 +1422,8 @@ coredump(struct proc *p)
 	char name[sizeof("/var/crash/") + MAXCOMLEN + sizeof(".core")];
 	char *dir = "";
 
+	p->p_p->ps_flags |= PS_COREDUMP;
+
 	/*
 	 * Don't dump if not root and the process has used set user or
 	 * group privileges, unless the nosuidcoredump sysctl is set to 2,
@@ -1540,6 +1550,9 @@ coredump_write(void *cookie, enum uio_seg segflg, const void *data, size_t len)
 
 	csize = len;
 	do {
+		if (io->io_proc->p_siglist & sigmask(SIGKILL))
+			return (EINTR);
+
 		/* Rest of the loop sleeps with lock held, so... */
 		yield();
 
diff --git a/sys/sys/proc.h b/sys/sys/proc.h
index da04d28451d..4760b86c058 100644
--- a/sys/sys/proc.h
+++ b/sys/sys/proc.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: proc.h,v 1.163 2012/09/11 15:44:19 deraadt Exp $	*/
+/*	$OpenBSD: proc.h,v 1.164 2013/01/15 02:03:38 deraadt Exp $	*/
 /*	$NetBSD: proc.h,v 1.44 1996/04/22 01:23:21 christos Exp $	*/
 
 /*-
@@ -245,6 +245,7 @@ struct process {
 #define	PS_SINGLEEXIT	_P_SINGLEEXIT
 #define	PS_SINGLEUNWIND	_P_SINGLEUNWIND
 #define	PS_EXITING	_P_EXITING
+#define	PS_COREDUMP	_P_COREDUMP
 
 struct proc {
 	TAILQ_ENTRY(proc) p_runq;
@@ -381,12 +382,10 @@ struct proc {
 
 /* Should be moved to machine-dependent areas. */
 #define	P_OWEUPC	0x008000	/* Owe proc an addupc() at next ast. */
-#define	_P_ISPWAIT	0x010000	/* Is parent of PPWAIT child. */
 
-/* XXX Not sure what to do with these, yet. */
-#define	P_SSTEP		0x020000	/* proc needs single-step fixup ??? */
+#define	_P_ISPWAIT	0x010000	/* Is parent of PPWAIT child. */
+#define	_P_COREDUMP	0x020000	/* busy coredumping */
 #define	_P_SUGIDEXEC	0x040000	/* last execve() was set[ug]id */
-
 #define	P_SUSPSINGLE	0x080000	/* Need to stop for single threading. */
 #define	P_NOZOMBIE	0x100000	/* Pid 1 waits for me instead of dad */
 #define _P_INEXEC	0x200000	/* Process is doing an exec right now */
@@ -415,7 +414,7 @@ struct proc {
 #define	P_BITS \
     ("\20\02CONTROLT\03INMEM\04SIGPAUSE\05PPWAIT\06PROFIL\07SELECT" \
      "\010SINTR\011SUGID\012SYSTEM\013TIMEOUT\014TRACED\015WAITED\016WEXIT" \
-     "\017EXEC\020PWEUPC\021ISPWAIT\022SSTEP\023SUGIDEXEC\024SUSPSINGLE" \
+     "\017EXEC\020PWEUPC\021ISPWAIT\022COREDUMPING\023SUGIDEXEC\024SUSPSINGLE" \
      "\025NOZOMBIE\026INEXEC\027SYSTRACE\030CONTINUED" \
      "\031SINGLEEXIT\032SINGLEUNWIND" \
      "\033THREAD\034SUSPSIG\035SOFTDEP\036STOPPED\037CPUPEG")
diff --git a/sys/uvm/uvm_unix.c b/sys/uvm/uvm_unix.c
index a94bf92cbf0..11bd29f977b 100644
--- a/sys/uvm/uvm_unix.c
+++ b/sys/uvm/uvm_unix.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: uvm_unix.c,v 1.44 2013/01/15 01:34:27 deraadt Exp $	*/
+/*	$OpenBSD: uvm_unix.c,v 1.45 2013/01/15 02:03:38 deraadt Exp $	*/
 /*	$NetBSD: uvm_unix.c,v 1.18 2000/09/13 15:00:25 thorpej Exp $	*/
 
 /*
@@ -237,6 +237,9 @@ uvm_coredump(struct proc *p, struct vnode *vp, struct ucred *cred,
 		coffset = 0;
 		csize = (int)cseg.c_size;
 		do {
+			if (p->p_siglist & sigmask(SIGKILL))
+				return (EINTR);
+
 			/* Rest of the loop sleeps with lock held, so... */
 			yield();