diff --git a/arch/um/include/tempfile.h b/arch/um/include/tempfile.h
index e36d9e0f51058dc88f730701bcde3b72037a4816..d441eac936b9830014e4ec650562d10f262dc0f8 100644
--- a/arch/um/include/tempfile.h
+++ b/arch/um/include/tempfile.h
@@ -9,13 +9,3 @@
 extern int make_tempfile(const char *template, char **tempname, int do_unlink);
 
 #endif
-/*
- * Overrides for Emacs so that we follow Linus's tabbing style.
- * Emacs will notice this stuff at the end of the file and automatically
- * adjust the settings for this buffer only.  This must remain at the end
- * of the file.
- * ---------------------------------------------------------------------------
- * Local variables:
- * c-file-style: "linux"
- * End:
- */
diff --git a/arch/um/kernel/mem.c b/arch/um/kernel/mem.c
index d1480ff0f2a61518ec1c27f755f9d53ab93a4d13..e85d65deea0db9c46f16085c8f168e56e4a475c5 100644
--- a/arch/um/kernel/mem.c
+++ b/arch/um/kernel/mem.c
@@ -24,8 +24,9 @@
 #include "init.h"
 #include "kern_constants.h"
 
-/* Changed during early boot */
+/* allocated in paging_init, zeroed in mem_init, and unchanged thereafter */
 unsigned long *empty_zero_page = NULL;
+/* allocated in paging_init and unchanged thereafter */
 unsigned long *empty_bad_page = NULL;
 pgd_t swapper_pg_dir[PTRS_PER_PGD];
 unsigned long long highmem;
diff --git a/arch/um/os-Linux/mem.c b/arch/um/os-Linux/mem.c
index 4203681e508d0a680635347c53a2168fdd3a68be..82b874580f639d102b125a052869db43fd5295f0 100644
--- a/arch/um/os-Linux/mem.c
+++ b/arch/um/os-Linux/mem.c
@@ -20,7 +20,13 @@
 
 #include <sys/param.h>
 
+/* Modified by which_tmpdir, which is called during early boot */
 static char *default_tmpdir = "/tmp";
+
+/*
+ *  Modified when creating the physical memory file and when checking
+ * the tmp filesystem for usability, both happening during early boot.
+ */
 static char *tempdir = NULL;
 
 static void __init find_tempdir(void)
@@ -83,6 +89,7 @@ static int next(int fd, char *buf, int size, char c)
 	return 1;
 }
 
+/* which_tmpdir is called only during early boot */
 static int checked_tmpdir = 0;
 
 /* Look for a tmpfs mounted at /dev/shm.  I couldn't find a cleaner