Make malloc and mbuf allocation mode flags nonoverlapping.

Under INVARIANTS whine if we get incompatible flags.

Submitted by:   imp

4 files changed, 39 insertions, 7 deletions

diff --git a/sys/kern/kern_malloc.c b/sys/kern/kern_malloc.c
index 04bf4b4..978fc6a 100644
--- a/sys/kern/kern_malloc.c
+++ b/sys/kern/kern_malloc.c
@@ -167,11 +167,28 @@ malloc(size, type, flags)
 #endif
 	register struct malloc_type *ksp = type;
 
+/* #ifdef INVARIANTS */
+	/*
+	 * To make sure that WAITOK or NOWAIT is set, but not more than
+	 * one, and check against the API botches that are common.
+	 */
+	indx = flags & (M_WAITOK | M_NOWAIT | M_DONTWAIT | M_TRYWAIT);
+	if (indx != M_NOWAIT && indx != M_WAITOK) {
+		static	struct timeval lasterr;
+		static	int curerr, once;
+		if (once == 0 && ppsratecheck(&lasterr, &curerr, 1)) {
+			printf("Bad malloc flags: %x\n", indx);
+			backtrace();
+			flags |= M_WAITOK;
+			once++;
+		}
+	}
+/* #endif */
 #if 0
 	if (size == 0)
 		Debugger("zero size malloc");
 #endif
-	if (!(flags & M_NOWAIT))
+	if (flags & M_WAITOK)
 		KASSERT(curthread->td_intr_nesting_level == 0,
 		   ("malloc(M_WAITOK) in interrupt context"));
 	if (size <= KMEM_ZMAX) {
diff --git a/sys/kern/subr_mbuf.c b/sys/kern/subr_mbuf.c
index 7906ab1..285d376 100644
--- a/sys/kern/subr_mbuf.c
+++ b/sys/kern/subr_mbuf.c
@@ -614,6 +614,21 @@ mb_alloc(struct mb_lstmngr *mb_list, int how, short type, short persist,
 	struct mb_bucket *bucket;
 	void *m;
 
+/* #ifdef INVARIANTS */
+	int flags;
+	
+	flags = how & (M_WAITOK | M_NOWAIT | M_DONTWAIT | M_TRYWAIT);
+	if (flags != M_DONTWAIT && flags != M_TRYWAIT) {
+		static	struct timeval lasterr;
+		static	int curerr;
+		if (ppsratecheck(&lasterr, &curerr, 1)) {
+			printf("Bad mbuf alloc flags: %x\n", flags);
+			backtrace();
+			how = M_TRYWAIT;
+		}
+	}
+/* #endif */
+
 	m = NULL;
 	if ((persist & MBP_PERSISTENT) != 0) {
 		/*
diff --git a/sys/sys/malloc.h b/sys/sys/malloc.h
index f610439..3d2d2cf 100644
--- a/sys/sys/malloc.h
+++ b/sys/sys/malloc.h
@@ -46,11 +46,11 @@
 /*
  * flags to malloc.
  */
-#define	M_WAITOK	0x0000
 #define	M_NOWAIT	0x0001		/* do not block */
-#define	M_USE_RESERVE	0x0002		/* can alloc out of reserve memory */
-#define	M_ZERO		0x0004		/* bzero the allocation */
-#define	M_NOVM		0x0008		/* don't ask VM for pages */
+#define	M_WAITOK	0x0002		/* do not block */
+#define	M_ZERO		0x0100		/* bzero the allocation */
+#define	M_NOVM		0x0200		/* don't ask VM for pages */
+#define	M_USE_RESERVE	0x0400		/* can alloc out of reserve memory */
 
 #define	M_MAGIC		877983977	/* time when first defined :-) */
 
diff --git a/sys/sys/mbuf.h b/sys/sys/mbuf.h
index d13964b..8035b8e 100644
--- a/sys/sys/mbuf.h
+++ b/sys/sys/mbuf.h
@@ -269,8 +269,8 @@ struct mbstat {
  * M_TRYWAIT means "block for mbuf_wait ticks at most if nothing is
  * available."
  */
-#define	M_DONTWAIT	1
-#define	M_TRYWAIT	0
+#define	M_DONTWAIT	0x4		/* don't conflict with M_NOWAIT */
+#define	M_TRYWAIT	0x8		/* or M_WAITOK */
 #define	M_WAIT		M_TRYWAIT	/* XXX: Deprecated. */
 
 #ifdef _KERNEL