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

[Andy Shevchenko <andriy.shevchenko@linux.intel.com>]

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@gmail.com>
> ---
>  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@intel.com>
Intel Finland Oy