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

Masami Hiramatsu
2020-01-10T16:04:39Z

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 <mhiramat@kernel.org>
---
init/main.c | 26 +++++++++++++++-----------
1 file changed, 15 insertions(+), 11 deletions(-)

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);
}

/*