4 files changed, 26 insertions, 14 deletions

diff --git a/arch/um/kernel/physmem.c b/arch/um/kernel/physmem.c
index 4c9861b421fd..f02596e9931d 100644
--- a/arch/um/kernel/physmem.c
+++ b/arch/um/kernel/physmem.c
@@ -89,8 +89,8 @@ void __init setup_physmem(unsigned long start, unsigned long reserve_end,
 	offset = uml_reserved - uml_physmem;
 	map_size = len - offset;
 	if(map_size <= 0) {
-		printf("Too few physical memory! Needed=%d, given=%d\n",
-		       offset, len);
+		os_warn("Too few physical memory! Needed=%lu, given=%lu\n",
+			offset, len);
 		exit(1);
 	}
 
@@ -99,9 +99,9 @@ void __init setup_physmem(unsigned long start, unsigned long reserve_end,
 	err = os_map_memory((void *) uml_reserved, physmem_fd, offset,
 			    map_size, 1, 1, 1);
 	if (err < 0) {
-		printf("setup_physmem - mapping %ld bytes of memory at 0x%p "
-		       "failed - errno = %d\n", map_size,
-		       (void *) uml_reserved, err);
+		os_warn("setup_physmem - mapping %ld bytes of memory at 0x%p "
+			"failed - errno = %d\n", map_size,
+			(void *) uml_reserved, err);
 		exit(1);
 	}
 
diff --git a/arch/um/kernel/trap.c b/arch/um/kernel/trap.c
index 59158871b9fc..4e6fcb32620f 100644
--- a/arch/um/kernel/trap.c
+++ b/arch/um/kernel/trap.c
@@ -183,6 +183,16 @@ void fatal_sigsegv(void)
 	os_dump_core();
 }
 
+/**
+ * segv_handler() - the SIGSEGV handler
+ * @sig:	the signal number
+ * @unused_si:	the signal info struct; unused in this handler
+ * @regs:	the ptrace register information
+ *
+ * The handler first extracts the faultinfo from the UML ptrace regs struct.
+ * If the userfault did not happen in an UML userspace process, bad_segv is called.
+ * Otherwise the signal did happen in a cloned userspace process, handle it.
+ */
 void segv_handler(int sig, struct siginfo *unused_si, struct uml_pt_regs *regs)
 {
 	struct faultinfo * fi = UPT_FAULTINFO(regs);
diff --git a/arch/um/kernel/um_arch.c b/arch/um/kernel/um_arch.c
index 7b5640117325..f433690b9b37 100644
--- a/arch/um/kernel/um_arch.c
+++ b/arch/um/kernel/um_arch.c
@@ -34,7 +34,7 @@ static char __initdata command_line[COMMAND_LINE_SIZE] = { 0 };
 static void __init add_arg(char *arg)
 {
 	if (strlen(command_line) + strlen(arg) + 1 > COMMAND_LINE_SIZE) {
-		printf("add_arg: Too many command line arguments!\n");
+		os_warn("add_arg: Too many command line arguments!\n");
 		exit(1);
 	}
 	if (strlen(command_line) > 0)
@@ -120,6 +120,7 @@ static const char *usage_string =
 
 static int __init uml_version_setup(char *line, int *add)
 {
+	/* Explicitly use printf() to show version in stdout */
 	printf("%s\n", init_utsname()->release);
 	exit(0);
 
@@ -148,8 +149,8 @@ __uml_setup("root=", uml_root_setup,
 
 static int __init no_skas_debug_setup(char *line, int *add)
 {
-	printf("'debug' is not necessary to gdb UML in skas mode - run \n");
-	printf("'gdb linux'\n");
+	os_warn("'debug' is not necessary to gdb UML in skas mode - run\n");
+	os_warn("'gdb linux'\n");
 
 	return 0;
 }
@@ -165,6 +166,7 @@ static int __init Usage(char *line, int *add)
 
 	printf(usage_string, init_utsname()->release);
 	p = &__uml_help_start;
+	/* Explicitly use printf() to show help in stdout */
 	while (p < &__uml_help_end) {
 		printf("%s", *p);
 		p++;
@@ -283,8 +285,8 @@ int __init linux_main(int argc, char **argv)
 
 	diff = UML_ROUND_UP(brk_start) - UML_ROUND_UP(&_end);
 	if (diff > 1024 * 1024) {
-		printf("Adding %ld bytes to physical memory to account for "
-		       "exec-shield gap\n", diff);
+		os_info("Adding %ld bytes to physical memory to account for "
+			"exec-shield gap\n", diff);
 		physmem_size += UML_ROUND_UP(brk_start) - UML_ROUND_UP(&_end);
 	}
 
@@ -324,8 +326,8 @@ int __init linux_main(int argc, char **argv)
 	end_vm = start_vm + virtmem_size;
 
 	if (virtmem_size < physmem_size)
-		printf("Kernel virtual memory size shrunk to %lu bytes\n",
-		       virtmem_size);
+		os_info("Kernel virtual memory size shrunk to %lu bytes\n",
+			virtmem_size);
 
 	os_flush_stdout();
 
diff --git a/arch/um/kernel/umid.c b/arch/um/kernel/umid.c
index f6cc3bd61781..10bf4aca529f 100644
--- a/arch/um/kernel/umid.c
+++ b/arch/um/kernel/umid.c
@@ -16,14 +16,14 @@ static int __init set_umid_arg(char *name, int *add)
 	int err;
 
 	if (umid_inited) {
-		printf("umid already set\n");
+		os_warn("umid already set\n");
 		return 0;
 	}
 
 	*add = 0;
 	err = set_umid(name);
 	if (err == -EEXIST)
-		printf("umid '%s' already in use\n", name);
+		os_warn("umid '%s' already in use\n", name);
 	else if (!err)
 		umid_inited = 1;