[PATCH 1/2] x86/setup: update boot_command_line with builtin_cmdline in separate function

Alexander Kuleshov
2015-04-08T09:31:58Z

This patch introduces setup_cmdline function which appends/overrides
boot_command_linew with builtin_cmdline if CONFIG_CMDLINE_BOOL is set.
Previously this functional was in the setup_arch, but we need to move
it for getting actual command line as early as possible in the
arch/x86/kernel/head{32,64}.c

Signed-off-by: Alexander Kuleshov <kuleshovmail@gmail.com>
---
arch/x86/kernel/head32.c | 1 +
arch/x86/kernel/head64.c | 1 +
arch/x86/kernel/setup.c | 31 ++++++++++++++++++-------------
include/linux/init.h | 6 +++++-
4 files changed, 25 insertions(+), 14 deletions(-)

diff --git a/arch/x86/kernel/head32.c b/arch/x86/kernel/head32.c
index 2911ef3..7ad0ad0 100644
--- a/arch/x86/kernel/head32.c
+++ b/arch/x86/kernel/head32.c
@@ -31,6 +31,7 @@ static void __init i386_default_early_setup(void)

asmlinkage __visible void __init i386_start_kernel(void)
{
+ setup_cmdline();
cr4_init_shadow();
sanitize_boot_params(&boot_params);

diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index c4f8d46..6eea2de 100644
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -171,6 +171,7 @@ asmlinkage __visible void __init x86_64_start_kernel(char * real_mode_data)
load_idt((const struct desc_ptr *)&idt_descr);

copy_bootdata(__va(real_mode_data));
+ setup_cmdline();

/*
* Load microcode early on BSP.
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 0a2421c..d578f37 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -841,6 +841,24 @@ dump_kernel_offset(struct notifier_block *self, unsigned long v, void *p)
}

/*
+ * Append/Override boot command line with builtin command line if need
+ */
+void __init setup_cmdline(void) {
+#ifdef CONFIG_CMDLINE_BOOL
+#ifdef CONFIG_CMDLINE_OVERRIDE
+ strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
+#else
+ if (builtin_cmdline[0]) {
+ /* append boot loader cmdline to builtin */
+ strlcat(builtin_cmdline, " ", COMMAND_LINE_SIZE);
+ strlcat(builtin_cmdline, boot_command_line, COMMAND_LINE_SIZE);
+ strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
+ }
+#endif
+#endif
+}
+
+/*
* Determine if we were loaded by an EFI loader. If so, then we have also been
* passed the efi memmap, systab, etc., so we should use these data structures
* for initialization. Note, the efi init code path is determined by the
@@ -968,19 +986,6 @@ void __init setup_arch(char **cmdline_p)
bss_resource.start = __pa_symbol(__bss_start);
bss_resource.end = __pa_symbol(__bss_stop)-1;

-#ifdef CONFIG_CMDLINE_BOOL
-#ifdef CONFIG_CMDLINE_OVERRIDE
- strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
-#else
- if (builtin_cmdline[0]) {
- /* append boot loader cmdline to builtin */
- strlcat(builtin_cmdline, " ", COMMAND_LINE_SIZE);
- strlcat(builtin_cmdline, boot_command_line, COMMAND_LINE_SIZE);
- strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
- }
-#endif
-#endif
-
strlcpy(command_line, boot_command_line, COMMAND_LINE_SIZE);
*cmdline_p = command_line;

diff --git a/include/linux/init.h b/include/linux/init.h
index 2df8e8d..af8f2ec 100644
--- a/include/linux/init.h
+++ b/include/linux/init.h
@@ -152,7 +152,11 @@ void setup_arch(char **);
void prepare_namespace(void);
void __init load_default_modules(void);
int __init init_rootfs(void);
-
+#ifdef CONFIG_CMDLINE_BOOL
+void __init setup_cmdline(void);
+#else
+static void __init setup_cmdline(void) {};
+#endif
extern void (*late_time_init)(void);

extern bool initcall_debug;
--
2.3.3.611.g09038fc.dirty