[PATCH v2 2/3] init/bootconfig: Reorder init parameter from bootconfig and cmdline

Masami Hiramatsu
2021-08-27T02:16:26Z

Reorder the init parameters from bootconfig and kernel cmdline
so that the kernel cmdline always be the last part of the
parameters as below.

" -- "[bootconfig init params][cmdline init params]

This change will help us to prevent that bootconfig init params
overwrite the init params which user gives in the command line.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
---
init/main.c | 23 ++++++++++++++---------
1 file changed, 14 insertions(+), 9 deletions(-)

diff --git a/init/main.c b/init/main.c
index d35c4a865adb..d08caed17c7f 100644
--- a/init/main.c
+++ b/init/main.c
@@ -153,10 +153,10 @@ static char *extra_init_args;
#ifdef CONFIG_BOOT_CONFIG
/* Is bootconfig on command line? */
static bool bootconfig_found;
-static bool initargs_found;
+static size_t initargs_offs;
#else
# define bootconfig_found false
-# define initargs_found false
+# define initargs_offs 0
#endif

static char *execute_command;
@@ -422,9 +422,9 @@ static void __init setup_boot_config(void)
if (IS_ERR(err) || !bootconfig_found)
return;

- /* parse_args() stops at '--' and returns an address */
+ /* parse_args() stops at the next param of '--' and returns an address */
if (err)
- initargs_found = true;
+ initargs_offs = err - tmp_cmdline;

if (!data) {
pr_err("'bootconfig' found on command line, but no bootconfig found\n");
@@ -655,16 +655,21 @@ static void __init setup_command_line(char *command_line)
* Append supplemental init boot args to saved_command_line
* so that user can check what command line options passed
* to init.
+ * The order should always be
+ * " -- "[bootconfig init-param][cmdline init-param]
*/
- len = strlen(saved_command_line);
- if (initargs_found) {
- saved_command_line[len++] = ' ';
+ if (initargs_offs) {
+ len = xlen + initargs_offs;
+ strcpy(saved_command_line + len, extra_init_args);
+ len += ilen - 4; /* strlen(extra_init_args) */
+ strcpy(saved_command_line + len,
+ boot_command_line + initargs_offs - 1);
} else {
+ len = strlen(saved_command_line);
strcpy(saved_command_line + len, " -- ");
len += 4;
+ strcpy(saved_command_line + len, extra_init_args);
}
-
- strcpy(saved_command_line + len, extra_init_args);
}
}