[PATCH 8/8] CMDLINE: arm64: convert to generic builtin command line

Christophe Leroy christophe.leroy at csgroup.eu
Thu Nov 23 17:39:50 AEDT 2023



Le 10/11/2023 à 02:38, Daniel Walker a écrit :
> This removes arm64 from the device tree handling of the
> command line arguments.

You should provide more details on how each existing Kconfig option is 
converted, for instance when CONFIG_CMDLINE_FORCE becomes 
CONFIG_CMDLINE_OVERRIDE.

> 
> The boot_command_line variable is populated inside the earliest
> user of the command line, which is in idreg-override.c.
> 
> The device tree should not be needed to do any further handling
> of the boot command line options.

should not be ? But what's the result at the end, is it needed or not ?

> 
> Cc: xe-linux-external at cisco.com
> Signed-off-by: Daniel Walker <danielwa at cisco.com>
> ---
>   arch/arm64/Kconfig                  | 33 +----------------------------
>   arch/arm64/include/asm/setup.h      |  4 ++++
>   arch/arm64/include/uapi/asm/setup.h |  2 ++
>   arch/arm64/kernel/idreg-override.c  |  9 ++++----
>   arch/arm64/kernel/pi/kaslr_early.c  | 14 ++++++------
>   5 files changed, 19 insertions(+), 43 deletions(-)
> 
> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> index 78f20e632712..d3b7fd1080d0 100644
> --- a/arch/arm64/Kconfig
> +++ b/arch/arm64/Kconfig
> @@ -131,6 +131,7 @@ config ARM64
>   	select GENERIC_ALLOCATOR
>   	select GENERIC_ARCH_TOPOLOGY
>   	select GENERIC_CLOCKEVENTS_BROADCAST
> +	select GENERIC_CMDLINE
>   	select GENERIC_CPU_AUTOPROBE
>   	select GENERIC_CPU_VULNERABILITIES
>   	select GENERIC_EARLY_IOREMAP
> @@ -2217,38 +2218,6 @@ config ARM64_ACPI_PARKING_PROTOCOL
>   	  protocol even if the corresponding data is present in the ACPI
>   	  MADT table.
>   
> -config CMDLINE
> -	string "Default kernel command string"
> -	default ""
> -	help
> -	  Provide a set of default command-line options at build time by
> -	  entering them here. As a minimum, you should specify the the
> -	  root device (e.g. root=/dev/nfs).
> -
> -choice
> -	prompt "Kernel command line type" if CMDLINE != ""
> -	default CMDLINE_FROM_BOOTLOADER
> -	help
> -	  Choose how the kernel will handle the provided default kernel
> -	  command line string.
> -
> -config CMDLINE_FROM_BOOTLOADER
> -	bool "Use bootloader kernel arguments if available"
> -	help
> -	  Uses the command-line options passed by the boot loader. If
> -	  the boot loader doesn't provide any, the default kernel command
> -	  string provided in CMDLINE will be used.
> -
> -config CMDLINE_FORCE
> -	bool "Always use the default kernel command string"
> -	help
> -	  Always use the default kernel command string, even if the boot
> -	  loader passes other arguments to the kernel.
> -	  This is useful if you cannot or don't want to change the
> -	  command-line options your boot loader passes to the kernel.
> -
> -endchoice
> -
>   config EFI_STUB
>   	bool
>   
> diff --git a/arch/arm64/include/asm/setup.h b/arch/arm64/include/asm/setup.h
> index f4af547ef54c..5a8037262cbb 100644
> --- a/arch/arm64/include/asm/setup.h
> +++ b/arch/arm64/include/asm/setup.h
> @@ -3,10 +3,13 @@
>   #ifndef __ARM64_ASM_SETUP_H
>   #define __ARM64_ASM_SETUP_H
>   
> +#ifndef __ASSEMBLY__
>   #include <linux/string.h>
> +#endif
>   
>   #include <uapi/asm/setup.h>
>   
> +#ifndef __ASSEMBLY__
>   void *get_early_fdt_ptr(void);
>   void early_fdt_map(u64 dt_phys);
>   
> @@ -30,5 +33,6 @@ static inline bool arch_parse_debug_rodata(char *arg)
>   	return false;
>   }
>   #define arch_parse_debug_rodata arch_parse_debug_rodata
> +#endif /* __ASSEMBLY__ */
>   
>   #endif
> diff --git a/arch/arm64/include/uapi/asm/setup.h b/arch/arm64/include/uapi/asm/setup.h
> index 5d703888f351..f5fc5b806369 100644
> --- a/arch/arm64/include/uapi/asm/setup.h
> +++ b/arch/arm64/include/uapi/asm/setup.h
> @@ -20,7 +20,9 @@
>   #ifndef __ASM_SETUP_H
>   #define __ASM_SETUP_H
>   
> +#ifndef __ASSEMBLY__
>   #include <linux/types.h>
> +#endif
>   
>   #define COMMAND_LINE_SIZE	2048
>   
> diff --git a/arch/arm64/kernel/idreg-override.c b/arch/arm64/kernel/idreg-override.c
> index 3addc09f8746..6334a9228909 100644
> --- a/arch/arm64/kernel/idreg-override.c
> +++ b/arch/arm64/kernel/idreg-override.c
> @@ -9,6 +9,7 @@
>   #include <linux/ctype.h>
>   #include <linux/kernel.h>
>   #include <linux/libfdt.h>
> +#include <linux/cmdline.h>
>   
>   #include <asm/cacheflush.h>
>   #include <asm/cpufeature.h>
> @@ -304,11 +305,11 @@ static __init void parse_cmdline(void)
>   {
>   	const u8 *prop = get_bootargs_cmdline();
>   
> -	if (IS_ENABLED(CONFIG_CMDLINE_FORCE) || !prop)
> -		__parse_cmdline(CONFIG_CMDLINE, true);
> +	strscpy(boot_command_line, prop, COMMAND_LINE_SIZE);
> +	cmdline_add_builtin(boot_command_line);
> +
> +	__parse_cmdline(boot_command_line, true);
>   
> -	if (!IS_ENABLED(CONFIG_CMDLINE_FORCE) && prop)
> -		__parse_cmdline(prop, true);
>   }
>   
>   /* Keep checkers quiet */
> diff --git a/arch/arm64/kernel/pi/kaslr_early.c b/arch/arm64/kernel/pi/kaslr_early.c
> index 17bff6e399e4..1e00bc01fa7a 100644
> --- a/arch/arm64/kernel/pi/kaslr_early.c
> +++ b/arch/arm64/kernel/pi/kaslr_early.c
> @@ -11,6 +11,7 @@
>   #include <linux/types.h>
>   #include <linux/sizes.h>
>   #include <linux/string.h>
> +#include <linux/cmdline.h>
>   
>   #include <asm/archrandom.h>
>   #include <asm/memory.h>
> @@ -42,7 +43,7 @@ static bool cmdline_contains_nokaslr(const u8 *cmdline)
>   
>   static bool is_kaslr_disabled_cmdline(void *fdt)
>   {
> -	if (!IS_ENABLED(CONFIG_CMDLINE_FORCE)) {
> +	if (!IS_ENABLED(CONFIG_CMDLINE_OVERRIDE)) {
>   		int node;
>   		const u8 *prop;
>   
> @@ -54,16 +55,15 @@ static bool is_kaslr_disabled_cmdline(void *fdt)
>   		if (!prop)
>   			goto out;
>   
> +		if (cmdline_contains_nokaslr(CMDLINE_STATIC_APPEND))
> +			return true;
>   		if (cmdline_contains_nokaslr(prop))
>   			return true;
> -
> -		if (IS_ENABLED(CONFIG_CMDLINE_EXTEND))
> -			goto out;
> -
> -		return false;
> +		if (cmdline_contains_nokaslr(CMDLINE_STATIC_PREPEND))
> +			return true;
>   	}
>   out:
> -	return cmdline_contains_nokaslr(CONFIG_CMDLINE);
> +	return cmdline_contains_nokaslr(cmdline_get_static_builtin());
>   }
>   
>   static u64 get_kaslr_seed(void *fdt)


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