diff mbox series

[v4,18/20] x86: Convert to GENERIC_CMDLINE

Message ID ab0fd4477964cdbf99e3dd2965a455aa3e738e4b.1617375802.git.christophe.leroy@csgroup.eu (mailing list archive)
State New, archived
Headers show
Series Implement GENERIC_CMDLINE | expand

Commit Message

Christophe Leroy April 2, 2021, 3:18 p.m. UTC 
This converts the architecture to GENERIC_CMDLINE.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/x86/Kconfig        | 45 ++---------------------------------------
 arch/x86/kernel/setup.c | 17 ++--------------
 2 files changed, 4 insertions(+), 58 deletions(-)

Comments

Rob Herring April 8, 2021, 7:41 p.m. UTC | #1 
On Fri, Apr 02, 2021 at 03:18:20PM +0000, Christophe Leroy wrote:
> This converts the architecture to GENERIC_CMDLINE.
> 
> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
> ---
>  arch/x86/Kconfig        | 45 ++---------------------------------------
>  arch/x86/kernel/setup.c | 17 ++--------------
>  2 files changed, 4 insertions(+), 58 deletions(-)
> 
> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> index a20684d56b4b..66b384228ca3 100644
> --- a/arch/x86/Kconfig
> +++ b/arch/x86/Kconfig
> @@ -104,6 +104,7 @@ config X86
>  	select ARCH_USE_QUEUED_SPINLOCKS
>  	select ARCH_USE_SYM_ANNOTATIONS
>  	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
> +	select ARCH_WANT_CMDLINE_PREPEND_BY_DEFAULT

Seems to be non-existent kconfig option.

>  	select ARCH_WANT_DEFAULT_BPF_JIT	if X86_64
>  	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
>  	select ARCH_WANT_HUGE_PMD_SHARE
> @@ -118,6 +119,7 @@ config X86
>  	select EDAC_SUPPORT
>  	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
>  	select GENERIC_CLOCKEVENTS_MIN_ADJUST
> +	select GENERIC_CMDLINE
>  	select GENERIC_CMOS_UPDATE
>  	select GENERIC_CPU_AUTOPROBE
>  	select GENERIC_CPU_VULNERABILITIES
> @@ -2358,49 +2360,6 @@ choice
>  
>  endchoice
>  
> -config CMDLINE_BOOL
> -	bool "Built-in kernel command line"
> -	help
> -	  Allow for specifying boot arguments to the kernel at
> -	  build time.  On some systems (e.g. embedded ones), it is
> -	  necessary or convenient to provide some or all of the
> -	  kernel boot arguments with the kernel itself (that is,
> -	  to not rely on the boot loader to provide them.)
> -
> -	  To compile command line arguments into the kernel,
> -	  set this option to 'Y', then fill in the
> -	  boot arguments in CONFIG_CMDLINE.
> -
> -	  Systems with fully functional boot loaders (i.e. non-embedded)
> -	  should leave this option set to 'N'.
> -
> -config CMDLINE
> -	string "Built-in kernel command string"
> -	depends on CMDLINE_BOOL
> -	default ""
> -	help
> -	  Enter arguments here that should be compiled into the kernel
> -	  image and used at boot time.  If the boot loader provides a
> -	  command line at boot time, it is appended to this string to
> -	  form the full kernel command line, when the system boots.
> -
> -	  However, you can use the CONFIG_CMDLINE_FORCE option to
> -	  change this behavior.
> -
> -	  In most cases, the command line (whether built-in or provided
> -	  by the boot loader) should specify the device for the root
> -	  file system.
> -
> -config CMDLINE_FORCE
> -	bool "Built-in command line overrides boot loader arguments"
> -	depends on CMDLINE_BOOL && CMDLINE != ""
> -	help
> -	  Set this option to 'Y' to have the kernel ignore the boot loader
> -	  command line, and use ONLY the built-in command line.
> -
> -	  This is used to work around broken boot loaders.  This should
> -	  be set to 'N' under normal conditions.
> -
>  config MODIFY_LDT_SYSCALL
>  	bool "Enable the LDT (local descriptor table)" if EXPERT
>  	default y
> diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
> index 6f2de58eeb54..3f274b02e51c 100644
> --- a/arch/x86/kernel/setup.c
> +++ b/arch/x86/kernel/setup.c
> @@ -5,6 +5,7 @@
>   * This file contains the setup_arch() code, which handles the architecture-dependent
>   * parts of early kernel initialization.
>   */
> +#include <linux/cmdline.h>
>  #include <linux/console.h>
>  #include <linux/crash_dump.h>
>  #include <linux/dma-map-ops.h>
> @@ -161,9 +162,6 @@ unsigned long saved_video_mode;
>  #define RAMDISK_LOAD_FLAG		0x4000
>  
>  static char __initdata command_line[COMMAND_LINE_SIZE];
> -#ifdef CONFIG_CMDLINE_BOOL
> -static char __initdata builtin_cmdline[COMMAND_LINE_SIZE] = CONFIG_CMDLINE;
> -#endif
>  
>  #if defined(CONFIG_EDD) || defined(CONFIG_EDD_MODULE)
>  struct edd edd;
> @@ -883,18 +881,7 @@ 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_FORCE
> -	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
> +	cmdline_build(boot_command_line, boot_command_line);
>  
>  	strlcpy(command_line, boot_command_line, COMMAND_LINE_SIZE);
>  	*cmdline_p = command_line;

Once this is all done, I wonder if we can get rid of the strlcpy and 
perhaps also cmdline_p.

Rob
Christophe Leroy April 9, 2021, 10:20 a.m. UTC | #2 
Le 08/04/2021 à 21:41, Rob Herring a écrit :
> On Fri, Apr 02, 2021 at 03:18:20PM +0000, Christophe Leroy wrote:
>> This converts the architecture to GENERIC_CMDLINE.
>>
>> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
>> ---
>>   arch/x86/Kconfig        | 45 ++---------------------------------------
>>   arch/x86/kernel/setup.c | 17 ++--------------
>>   2 files changed, 4 insertions(+), 58 deletions(-)
>>
>> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
>> index a20684d56b4b..66b384228ca3 100644
>> --- a/arch/x86/Kconfig
>> +++ b/arch/x86/Kconfig
>> @@ -104,6 +104,7 @@ config X86
>>   	select ARCH_USE_QUEUED_SPINLOCKS
>>   	select ARCH_USE_SYM_ANNOTATIONS
>>   	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
>> +	select ARCH_WANT_CMDLINE_PREPEND_BY_DEFAULT
> 
> Seems to be non-existent kconfig option.

Oops. Added in v5.

>> @@ -883,18 +881,7 @@ 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_FORCE
>> -	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
>> +	cmdline_build(boot_command_line, boot_command_line);
>>   
>>   	strlcpy(command_line, boot_command_line, COMMAND_LINE_SIZE);
>>   	*cmdline_p = command_line;
> 
> Once this is all done, I wonder if we can get rid of the strlcpy and
> perhaps also cmdline_p.
> 

It seems rather complicated, in init/main.c you have heavy manipulations of command lines which 
seems to be done in setup_command_line() which seems to add stuff in front of command lines, at the 
end we end up with several command lines:

/* Untouched saved command line (eg. for /proc) */
char *saved_command_line;
/* Command line for parameter parsing */
static char *static_command_line;
/* Untouched extra command line */
static char *extra_command_line;

Some of them come from the cmdline_p which others are from boot_command_line.

I think a cleanup on all that stuff would be worth it as a further step.
diff mbox series

Patch

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index a20684d56b4b..66b384228ca3 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -104,6 +104,7 @@  config X86
 	select ARCH_USE_QUEUED_SPINLOCKS
 	select ARCH_USE_SYM_ANNOTATIONS
 	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
+	select ARCH_WANT_CMDLINE_PREPEND_BY_DEFAULT
 	select ARCH_WANT_DEFAULT_BPF_JIT	if X86_64
 	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
 	select ARCH_WANT_HUGE_PMD_SHARE
@@ -118,6 +119,7 @@  config X86
 	select EDAC_SUPPORT
 	select GENERIC_CLOCKEVENTS_BROADCAST	if X86_64 || (X86_32 && X86_LOCAL_APIC)
 	select GENERIC_CLOCKEVENTS_MIN_ADJUST
+	select GENERIC_CMDLINE
 	select GENERIC_CMOS_UPDATE
 	select GENERIC_CPU_AUTOPROBE
 	select GENERIC_CPU_VULNERABILITIES
@@ -2358,49 +2360,6 @@  choice
 
 endchoice
 
-config CMDLINE_BOOL
-	bool "Built-in kernel command line"
-	help
-	  Allow for specifying boot arguments to the kernel at
-	  build time.  On some systems (e.g. embedded ones), it is
-	  necessary or convenient to provide some or all of the
-	  kernel boot arguments with the kernel itself (that is,
-	  to not rely on the boot loader to provide them.)
-
-	  To compile command line arguments into the kernel,
-	  set this option to 'Y', then fill in the
-	  boot arguments in CONFIG_CMDLINE.
-
-	  Systems with fully functional boot loaders (i.e. non-embedded)
-	  should leave this option set to 'N'.
-
-config CMDLINE
-	string "Built-in kernel command string"
-	depends on CMDLINE_BOOL
-	default ""
-	help
-	  Enter arguments here that should be compiled into the kernel
-	  image and used at boot time.  If the boot loader provides a
-	  command line at boot time, it is appended to this string to
-	  form the full kernel command line, when the system boots.
-
-	  However, you can use the CONFIG_CMDLINE_FORCE option to
-	  change this behavior.
-
-	  In most cases, the command line (whether built-in or provided
-	  by the boot loader) should specify the device for the root
-	  file system.
-
-config CMDLINE_FORCE
-	bool "Built-in command line overrides boot loader arguments"
-	depends on CMDLINE_BOOL && CMDLINE != ""
-	help
-	  Set this option to 'Y' to have the kernel ignore the boot loader
-	  command line, and use ONLY the built-in command line.
-
-	  This is used to work around broken boot loaders.  This should
-	  be set to 'N' under normal conditions.
-
 config MODIFY_LDT_SYSCALL
 	bool "Enable the LDT (local descriptor table)" if EXPERT
 	default y
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 6f2de58eeb54..3f274b02e51c 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -5,6 +5,7 @@ 
  * This file contains the setup_arch() code, which handles the architecture-dependent
  * parts of early kernel initialization.
  */
+#include <linux/cmdline.h>
 #include <linux/console.h>
 #include <linux/crash_dump.h>
 #include <linux/dma-map-ops.h>
@@ -161,9 +162,6 @@  unsigned long saved_video_mode;
 #define RAMDISK_LOAD_FLAG		0x4000
 
 static char __initdata command_line[COMMAND_LINE_SIZE];
-#ifdef CONFIG_CMDLINE_BOOL
-static char __initdata builtin_cmdline[COMMAND_LINE_SIZE] = CONFIG_CMDLINE;
-#endif
 
 #if defined(CONFIG_EDD) || defined(CONFIG_EDD_MODULE)
 struct edd edd;
@@ -883,18 +881,7 @@  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_FORCE
-	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
+	cmdline_build(boot_command_line, boot_command_line);
 
 	strlcpy(command_line, boot_command_line, COMMAND_LINE_SIZE);
 	*cmdline_p = command_line;