Update to FreeBSD head 2017-10-01

Git mirror commit b2f0376b45428f13151d229c5ae9d4d8f74acbd1.

Update #3472.

1 files changed, 89 insertions, 11 deletions

diff --git a/freebsd/sys/kern/kern_sysctl.c b/freebsd/sys/kern/kern_sysctl.c
index 90b15444..e99a8bd6 100644
--- a/freebsd/sys/kern/kern_sysctl.c
+++ b/freebsd/sys/kern/kern_sysctl.c
@@ -90,7 +90,7 @@ static MALLOC_DEFINE(M_SYSCTLTMP, "sysctltmp", "sysctl temp output buffer");
  * sysctl requests larger than a single page via an exclusive lock.
  */
 static struct rmlock sysctllock;
-static struct sx sysctlmemlock;
+static struct sx __exclusive_cache_line sysctlmemlock;
 
 #define	SYSCTL_WLOCK()		rm_wlock(&sysctllock)
 #define	SYSCTL_WUNLOCK()	rm_wunlock(&sysctllock)
@@ -327,6 +327,91 @@ sysctl_load_tunable_by_oid_locked(struct sysctl_oid *oidp)
 }
 #endif /* __rtems__ */
 
+static int
+sbuf_printf_drain(void *arg __unused, const char *data, int len)
+{
+
+	return (printf("%.*s", len, data));
+}
+
+/*
+ * Locate the path to a given oid.  Returns the length of the resulting path,
+ * or -1 if the oid was not found.  nodes must have room for CTL_MAXNAME
+ * elements and be NULL initialized.
+ */
+static int
+sysctl_search_oid(struct sysctl_oid **nodes, struct sysctl_oid *needle)
+{
+	int indx;
+
+	SYSCTL_ASSERT_LOCKED();
+	indx = 0;
+	while (indx < CTL_MAXNAME && indx >= 0) {
+		if (nodes[indx] == NULL && indx == 0)
+			nodes[indx] = SLIST_FIRST(&sysctl__children);
+		else if (nodes[indx] == NULL)
+			nodes[indx] = SLIST_FIRST(&nodes[indx - 1]->oid_children);
+		else
+			nodes[indx] = SLIST_NEXT(nodes[indx], oid_link);
+
+		if (nodes[indx] == needle)
+			return (indx + 1);
+
+		if (nodes[indx] == NULL) {
+			indx--;
+			continue;
+		}
+
+		if ((nodes[indx]->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
+			indx++;
+			continue;
+		}
+	}
+	return (-1);
+}
+
+static void
+sysctl_warn_reuse(const char *func, struct sysctl_oid *leaf)
+{
+	struct sysctl_oid *nodes[CTL_MAXNAME];
+	char buf[128];
+	struct sbuf sb;
+	int rc, i;
+
+	(void)sbuf_new(&sb, buf, sizeof(buf), SBUF_FIXEDLEN | SBUF_INCLUDENUL);
+	sbuf_set_drain(&sb, sbuf_printf_drain, NULL);
+
+	sbuf_printf(&sb, "%s: can't re-use a leaf (", __func__);
+
+	memset(nodes, 0, sizeof(nodes));
+	rc = sysctl_search_oid(nodes, leaf);
+	if (rc > 0) {
+		for (i = 0; i < rc; i++)
+			sbuf_printf(&sb, "%s%.*s", nodes[i]->oid_name,
+			    i != (rc - 1), ".");
+	} else {
+		sbuf_printf(&sb, "%s", leaf->oid_name);
+	}
+	sbuf_printf(&sb, ")!\n");
+
+	(void)sbuf_finish(&sb);
+}
+
+#ifdef SYSCTL_DEBUG
+static int
+sysctl_reuse_test(SYSCTL_HANDLER_ARGS)
+{
+	struct rm_priotracker tracker;
+
+	SYSCTL_RLOCK(&tracker);
+	sysctl_warn_reuse(__func__, oidp);
+	SYSCTL_RUNLOCK(&tracker);
+	return (0);
+}
+SYSCTL_PROC(_sysctl, 0, reuse_test, CTLTYPE_STRING|CTLFLAG_RD|CTLFLAG_MPSAFE,
+	0, 0, sysctl_reuse_test, "-", "");
+#endif
+
 void
 sysctl_register_oid(struct sysctl_oid *oidp)
 {
@@ -347,7 +432,7 @@ sysctl_register_oid(struct sysctl_oid *oidp)
 			p->oid_refcnt++;
 			return;
 		} else {
-			printf("can't re-use a leaf (%s)!\n", p->oid_name);
+			sysctl_warn_reuse(__func__, p);
 			return;
 		}
 	}
@@ -721,8 +806,8 @@ sysctl_add_oid(struct sysctl_ctx_list *clist, struct sysctl_oid_list *parent,
 			SYSCTL_WUNLOCK();
 			return (oidp);
 		} else {
+			sysctl_warn_reuse(__func__, oidp);
 			SYSCTL_WUNLOCK();
-			printf("can't re-use a leaf (%s)!\n", name);
 			return (NULL);
 		}
 	}
@@ -2005,16 +2090,9 @@ userland_sysctl(struct thread *td, int *name, u_int namelen, void *old,
 		}
 	}
 	req.validlen = req.oldlen;
-
-	if (old) {
-		if (!useracc(old, req.oldlen, VM_PROT_WRITE))
-			return (EFAULT);
-		req.oldptr= old;
-	}
+	req.oldptr = old;
 
 	if (new != NULL) {
-		if (!useracc(new, newlen, VM_PROT_READ))
-			return (EFAULT);
 		req.newlen = newlen;
 		req.newptr = new;
 	}