[v6,06/22] init/main.c: Alloc initcall_command_line in do_initcall() and free it

Commit Message

Masami Hiramatsu (Google) Jan. 10, 2020, 4:04 p.m. UTC

Since initcall_command_line is used as a temporary buffer,
it could be freed after usage. Allocate it in do_initcall()
and free it after used.

Signed-off-by: Masami Hiramatsu <[e-mail]>
---
 init/main.c |   26 +++++++++++++++-----------
 1 file changed, 15 insertions(+), 11 deletions(-)

Patch

diff --git a/init/main.c b/init/main.c
index 59c418a57f92..0b4e0c8ccf16 100644
--- a/init/main.c
+++ b/init/main.c
@@ -137,8 +137,6 @@  char __initdata boot_command_line[COMMAND_LINE_SIZE];
 char *saved_command_line;
 /* Command line for parameter parsing */
 static char *static_command_line;
-/* Command line for per-initcall parameter parsing */
-static char *initcall_command_line;
 
 static char *execute_command;
 static char *ramdisk_execute_command;
@@ -433,10 +431,6 @@  static void __init setup_command_line(char *command_line)
 	if (!saved_command_line)
 		panic("%s: Failed to allocate %zu bytes\n", __func__, len);
 
-	initcall_command_line =	memblock_alloc(len, SMP_CACHE_BYTES);
-	if (!initcall_command_line)
-		panic("%s: Failed to allocate %zu bytes\n", __func__, len);
-
 	static_command_line = memblock_alloc(len, SMP_CACHE_BYTES);
 	if (!static_command_line)
 		panic("%s: Failed to allocate %zu bytes\n", __func__, len);
@@ -1044,13 +1038,12 @@  static const char *initcall_level_names[] __initdata = {
 	"late",
 };
 
-static void __init do_initcall_level(int level)
+static void __init do_initcall_level(int level, char *command_line)
 {
 	initcall_entry_t *fn;
 
-	strcpy(initcall_command_line, saved_command_line);
 	parse_args(initcall_level_names[level],
-		   initcall_command_line, __start___param,
+		   command_line, __start___param,
 		   __stop___param - __start___param,
 		   level, level,
 		   NULL, &repair_env_string);
@@ -1063,9 +1056,20 @@  static void __init do_initcall_level(int level)
 static void __init do_initcalls(void)
 {
 	int level;
+	size_t len = strlen(saved_command_line) + 1;
+	char *command_line;
+
+	command_line = kzalloc(len, GFP_KERNEL);
+	if (!command_line)
+		panic("%s: Failed to allocate %zu bytes\n", __func__, len);
+
+	for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++) {
+		/* Parser modifies command_line, restore it each time */
+		strcpy(command_line, saved_command_line);
+		do_initcall_level(level, command_line);
+	}
 
-	for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++)
-		do_initcall_level(level);
+	kfree(command_line);
 }
 
 /*