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

From: Christophe Leroy
Date: Thu Nov 23 2023 - 01:39:58 EST




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@xxxxxxxxx
> Signed-off-by: Daniel Walker <danielwa@xxxxxxxxx>
> ---
> 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)