From f197bcb435f419c7c92d3c8aff1264b07dd1b50b Mon Sep 17 00:00:00 2001
From: David van Moolenbroek <david@minix3.org>
Date: Wed, 2 Dec 2009 10:06:58 +0000
Subject: [PATCH] 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        | 1 -
 include/minix/type.h    | 3 +--
 lib/syslib/alloc_util.c | 4 ++--
 servers/mfs/cache.c     | 3 +--
 servers/pm/misc.c       | 7 +++++++
 5 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/etc/drivers.conf b/etc/drivers.conf
index eb0c3e647..ef62bca24 100644
--- a/etc/drivers.conf
+++ b/etc/drivers.conf
@@ -290,7 +290,6 @@ driver mfs
 		SAFECOPYTO	# 32
 		GETINFO
 		SETGRANT	# 34
-                UMAP            # 14
 		PROFBUF		# 38
 		SYSCTL
 		;
diff --git a/include/minix/type.h b/include/minix/type.h
index 4dd0edfe9..d5a526c3b 100644
--- a/include/minix/type.h
+++ b/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);	\
 		}	\
 	}
diff --git a/lib/syslib/alloc_util.c b/lib/syslib/alloc_util.c
index 52d7792e5..1fe2e2ec9 100644
--- a/lib/syslib/alloc_util.c
+++ b/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;
diff --git a/servers/mfs/cache.c b/servers/mfs/cache.c
index 1936479a7..5ccf9aa34 100644
--- a/servers/mfs/cache.c
+++ b/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)
diff --git a/servers/pm/misc.c b/servers/pm/misc.c
index 2d2c3cdf7..27e0aed91 100644
--- a/servers/pm/misc.c
+++ b/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);
-- 
2.44.0