# This adds a check that /tmp is not mounted noexec.  UML needs to be able
# to do PROT_EXEC mmaps of temp files.  Previously, a noexec /tmp would
# cause an early mysterious UML crash.
Index: um/arch/um/include/mem_user.h
===================================================================
--- um.orig/arch/um/include/mem_user.h	2004-06-29 08:42:03.000000000 -0400
+++ um/arch/um/include/mem_user.h	2004-09-20 11:28:09.000000000 -0400
@@ -66,6 +66,7 @@
 extern int protect_memory(unsigned long addr, unsigned long len, 
 			  int r, int w, int x, int must_succeed);
 extern unsigned long get_kmem_end(void);
+extern void check_tmpexec(void);
 
 #endif
 
Index: um/arch/um/kernel/mem_user.c
===================================================================
--- um.orig/arch/um/kernel/mem_user.c	2004-08-12 14:25:02.000000000 -0400
+++ um/arch/um/kernel/mem_user.c	2004-09-20 11:29:26.000000000 -0400
@@ -83,6 +83,26 @@
 	return(fd);
 }
 
+void check_tmpexec(void)
+{
+	void *addr;
+	int err, fd = create_tmp_file(UM_KERN_PAGE_SIZE);
+
+	addr = mmap(NULL, UM_KERN_PAGE_SIZE, 
+		    PROT_READ | PROT_WRITE | PROT_EXEC, MAP_PRIVATE, fd, 0);
+	printf("Checking PROT_EXEC mmap in /tmp...");
+	fflush(stdout);
+	if(addr == MAP_FAILED){
+		err = errno;
+		perror("failed");
+		if(err == EPERM)
+			printf("/tmp must be not mounted noexec\n");
+		exit(1);
+	}
+	printf("OK\n");
+	munmap(addr, UM_KERN_PAGE_SIZE);
+}
+
 static int have_devanon(void)
 {
 	int fd;
@@ -109,7 +129,7 @@
 		exit(1);
 	}
 
-	addr = mmap(NULL, len, PROT_READ | PROT_WRITE , MAP_PRIVATE, fd, 0);
+	addr = mmap(NULL, len, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
 	if(addr == MAP_FAILED){
 		os_print_error((int) addr, "mapping physmem file");
 		exit(1);
Index: um/arch/um/kernel/um_arch.c
===================================================================
--- um.orig/arch/um/kernel/um_arch.c	2004-08-12 21:25:45.000000000 -0400
+++ um/arch/um/kernel/um_arch.c	2004-09-20 11:28:09.000000000 -0400
@@ -319,6 +319,11 @@
 	uml_start = CHOOSE_MODE_PROC(set_task_sizes_tt, set_task_sizes_skas, 0,
 				     &host_task_size, &task_size);
 
+	/* Need to check this early because mmapping happens before the
+	 * kernel is running.
+	 */
+	check_tmpexec();
+
 	brk_start = (unsigned long) sbrk(0);
 	CHOOSE_MODE_PROC(before_mem_tt, before_mem_skas, brk_start);
 	/* Increase physical memory size for exec-shield users