Re: [PATCH v2 1/2] x86/setup: introduce setup_bultin_cmdline

From: Andy Shevchenko
Date: Mon May 11 2015 - 06:36:25 EST


On Mon, 2015-05-11 at 16:09 +0600, Alexander Kuleshov wrote:
> This patch introduces setup_builtin_cmdline function which appends/overrides
> boot_command_line with the 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 for the earlyprintk setup.
>

Thanks for update. See my comments below. Don't forget to address what
Borislav told already twice.

> Changes:
>
> v2: function renamed from setup_cmdline to setup_builtin_cmdline to
> avoid conflict with the setup_cmdline from the arch/x86/kernel/kexec-bzimage64.c

You mare remove those lines since it should be a part of cover letter
now. Or, if you still wish to have them, move after --- line.

>
> Signed-off-by: Alexander Kuleshov <kuleshovmail@xxxxxxxxx>
> ---
> arch/x86/include/asm/setup.h | 3 ++-
> arch/x86/kernel/head32.c | 1 +
> arch/x86/kernel/head64.c | 1 +
> arch/x86/kernel/setup.c | 28 +++++++++++++++-------------
> 4 files changed, 19 insertions(+), 14 deletions(-)
>
> diff --git a/arch/x86/include/asm/setup.h b/arch/x86/include/asm/setup.h
> index f69e06b..dde474a 100644
> --- a/arch/x86/include/asm/setup.h
> +++ b/arch/x86/include/asm/setup.h
> @@ -24,6 +24,7 @@
> #define OLD_CL_ADDRESS 0x020 /* Relative to real mode data */
> #define NEW_CL_POINTER 0x228 /* Relative to real mode data */
>
> +
> #ifndef __ASSEMBLY__
> #include <asm/bootparam.h>
> #include <asm/x86_init.h>

This chunk is not needed.

> @@ -117,8 +118,8 @@ asmlinkage void __init i386_start_kernel(void);
> #else
> asmlinkage void __init x86_64_start_kernel(char *real_mode);
> asmlinkage void __init x86_64_start_reservations(char *real_mode_data);
> -

Why? It shouldn't be here since it's redundant change.

> #endif /* __i386__ */
> +void __init setup_builtin_cmdline(void);
> #endif /* _SETUP */
> #else
> #define RESERVE_BRK(name,sz) \
> diff --git a/arch/x86/kernel/head32.c b/arch/x86/kernel/head32.c
> index 2911ef3..95eed21 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_builtin_cmdline();
> cr4_init_shadow();
> sanitize_boot_params(&boot_params);
>
> diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
> index 2b55ee6..df290d1 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_builtin_cmdline();
>
> /*
> * Load microcode early on BSP.
> diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
> index d74ac33..c9d1896 100644
> --- a/arch/x86/kernel/setup.c
> +++ b/arch/x86/kernel/setup.c
> @@ -845,6 +845,21 @@ dump_kernel_offset(struct notifier_block *self, unsigned long v, void *p)
> return 0;
> }
>
> +void __init setup_builtin_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
> +}
> +

It might be a nice idea to split this to two patches:
1) split helper function,
2) update usage of it.

> /*
> * 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
> @@ -973,19 +988,6 @@ 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;
>


--
Andy Shevchenko <andriy.shevchenko@xxxxxxxxx>
Intel Finland Oy

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