Protect the ps_pgrp pointer by either the KERNEL_LOCK or the ps_mtx.

This should be enough to be on the safe side when unlocking ptsignal
where a pr->ps_pgrp->pg_jobc == 0 check happens.
OK mpi@ kettenis@

diff --git a/sys/kern/kern_proc.c b/sys/kern/kern_proc.c
index f061b06..7abbab5 100644 (file)
--- a/sys/kern/kern_proc.c
+++ b/sys/kern/kern_proc.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: kern_proc.c,v 1.100 2024/10/15 13:49:26 claudio Exp $ */
+/*     $OpenBSD: kern_proc.c,v 1.101 2024/10/22 11:54:04 claudio Exp $ */
 /*     $NetBSD: kern_proc.c,v 1.14 1996/02/09 18:59:41 christos Exp $  */
 
 /*
@@ -319,7 +319,9 @@ enterthispgrp(struct process *pr, struct pgrp *pgrp)
        fixjobc(pr, savepgrp, 0);
 
        LIST_REMOVE(pr, ps_pglist);
+       mtx_enter(&pr->ps_mtx);
        pr->ps_pgrp = pgrp;
+       mtx_leave(&pr->ps_mtx);
        LIST_INSERT_HEAD(&pgrp->pg_members, pr, ps_pglist);
        if (LIST_EMPTY(&savepgrp->pg_members))
                pgdelete(savepgrp);
@@ -337,7 +339,9 @@ leavepgrp(struct process *pr)
        LIST_REMOVE(pr, ps_pglist);
        if (LIST_EMPTY(&pr->ps_pgrp->pg_members))
                pgdelete(pr->ps_pgrp);
+       mtx_enter(&pr->ps_mtx);
        pr->ps_pgrp = NULL;
+       mtx_leave(&pr->ps_mtx);
 }
 
 /*

diff --git a/sys/kern/kern_sig.c b/sys/kern/kern_sig.c
index 98edd73..6d3800c 100644 (file)
--- a/sys/kern/kern_sig.c
+++ b/sys/kern/kern_sig.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: kern_sig.c,v 1.343 2024/10/17 09:11:35 claudio Exp $  */
+/*     $OpenBSD: kern_sig.c,v 1.344 2024/10/22 11:54:04 claudio Exp $  */
 /*     $NetBSD: kern_sig.c,v 1.54 1996/04/22 01:38:32 christos Exp $   */
 
 /*
@@ -1436,10 +1436,14 @@ cursig(struct proc *p, struct sigctx *sctx, int deep)
                         * process group, ignore tty stop signals.
                         */
                        if (prop & SA_STOP) {
+                               mtx_enter(&pr->ps_mtx);
                                if (pr->ps_flags & PS_TRACED ||
                                    (pr->ps_pgrp->pg_jobc == 0 &&
-                                   prop & SA_TTYSTOP))
+                                   prop & SA_TTYSTOP)) {
+                                       mtx_leave(&pr->ps_mtx);
                                        break;  /* == ignore */
+                               }
+                               mtx_leave(&pr->ps_mtx);
                                pr->ps_xsig = signum;
                                SCHED_LOCK();
                                proc_stop(p, 1);

diff --git a/sys/sys/proc.h b/sys/sys/proc.h
index 4667ddb..b76f2bb 100644 (file)
--- a/sys/sys/proc.h
+++ b/sys/sys/proc.h
@@ -1,4 +1,4 @@
-/*     $OpenBSD: proc.h,v 1.375 2024/10/15 13:49:26 claudio Exp $      */
+/*     $OpenBSD: proc.h,v 1.376 2024/10/22 11:54:05 claudio Exp $      */
 /*     $NetBSD: proc.h,v 1.44 1996/04/22 01:23:21 christos Exp $       */
 
 /*-
@@ -227,7 +227,7 @@ struct process {
 /* The following fields are all copied upon creation in process_new. */
 #define        ps_startcopy    ps_limit
        struct  plimit *ps_limit;       /* [m,R] Process limits. */
-       struct  pgrp *ps_pgrp;          /* Pointer to process group. */
+       struct  pgrp *ps_pgrp;          /* [K|m] Pointer to process group. */
 
        char    ps_comm[_MAXCOMLEN];    /* command name, incl NUL */