Allow servers to run with fewer privileges:

- allow non-root processes to get their own endpoint
- make alloc_contig() call sys_umap() only when requested

etc/drivers.conf

@@ -290,7 +290,6 @@ driver mfs
 		SAFECOPYTO	# 32
 		GETINFO
 		SETGRANT	# 34
-                UMAP            # 14
 		PROFBUF		# 38
 		SYSCTL
 		;

include/minix/type.h

@@ -162,8 +162,7 @@ struct memory {
 
 #define STATICINIT(v, n) \
 	if(!(v)) {	\
-		phys_bytes myph; \
-		if(!((v) = alloc_contig(sizeof(*(v)) * (n), 0, &myph))) { \
+		if(!((v) = alloc_contig(sizeof(*(v)) * (n), 0, NULL))) { \
 			panic(__FILE__, "allocating " #v " failed", n);	\
 		}	\
 	}

lib/syslib/alloc_util.c

@@ -66,8 +66,8 @@ void *alloc_contig(size_t len, int flags, phys_bytes *phys)
 			buf += align - (buf % align);
 	}
 
-	/* Get physical address. */
-        if(sys_umap_data_fb(SELF, buf, len, phys) != OK)
+	/* Get physical address, if requested. */
+        if(phys != NULL && sys_umap_data_fb(SELF, buf, len, phys) != OK)
 		panic("alloc_contig.c", "sys_umap_data_fb failed", NO_NUM);
 
 	return (void *) buf;

servers/mfs/cache.c

@@ -82,10 +82,9 @@ int only_search;		/* if NO_READ, don't read, else act normal */
   if ((bp = front) == NIL_BUF) panic(__FILE__,"all buffers in use", NR_BUFS);
 
   if(bp->b_bytes < fs_block_size) {
-	phys_bytes ph;
 	ASSERT(!bp->bp);
 	ASSERT(bp->b_bytes == 0);
-	if(!(bp->bp = alloc_contig(fs_block_size, 0, &ph))) {
+	if(!(bp->bp = alloc_contig(fs_block_size, 0, NULL))) {
 		printf("MFS: couldn't allocate a new block.\n");
 		for(bp = front;
 			bp && bp->b_bytes < fs_block_size; bp = bp->b_next)

servers/pm/misc.c

@@ -314,6 +314,13 @@ PUBLIC int do_getprocnr()
   /* This call should be moved to DS. */
   if (mp->mp_effuid != 0)
   {
+	/* For now, allow non-root processes to request their own endpoint. */
+	if (m_in.pid < 0 && m_in.namelen == 0) {
+		mp->mp_reply.PM_ENDPT = who_e;
+		mp->mp_reply.PM_PENDPT = NONE;
+		return OK;
+	}
+
 	printf("PM: unauthorized call of do_getprocnr by proc %d\n",
 		mp->mp_endpoint);
 	sys_sysctl_stacktrace(mp->mp_endpoint);