Re: [PATCH] x86: move parse_early_param to earlier code for add_efi_memmap

From: Dave Young
Date: Thu Dec 14 2017 - 05:41:32 EST


On 11/30/17 at 01:23pm, Dave Young wrote:
> 'add_efi_memmap' is an early param, but do_add_efi_memmap() has no
> chance to run because the code path is before parse_early_param().
> I believe it worked when the param was introduced but probably later
> some other changes caused the wrong order and nobody noticed it.
>
> Move parse_early_param before efi_memblock_x86_reserve_range to fix
> this.
>
> Signed-off-by: Dave Young <dyoung@xxxxxxxxxx>
> ---
> arch/x86/kernel/setup.c | 55 ++++++++++++++++++++++++------------------------
> 1 file changed, 28 insertions(+), 27 deletions(-)
>
> --- linux-x86.orig/arch/x86/kernel/setup.c
> +++ linux-x86/arch/x86/kernel/setup.c
> @@ -897,6 +897,34 @@ void __init setup_arch(char **cmdline_p)
> rd_prompt = ((boot_params.hdr.ram_size & RAMDISK_PROMPT_FLAG) != 0);
> rd_doload = ((boot_params.hdr.ram_size & RAMDISK_LOAD_FLAG) != 0);
> #endif
> +
> +#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;
> +
> + /*
> + * x86_configure_nx() is called before parse_early_param() to detect
> + * whether hardware doesn't support NX (so that the early EHCI debug
> + * console setup can safely call set_fixmap()). It may then be called
> + * again from within noexec_setup() during parsing early parameters
> + * to honor the respective command line option.
> + */
> + x86_configure_nx();
> +
> + parse_early_param();
> +
> #ifdef CONFIG_EFI
> if (!strncmp((char *)&boot_params.efi_info.efi_loader_signature,
> EFI32_LOADER_SIGNATURE, 4)) {
> @@ -935,33 +963,6 @@ 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;
> -
> - /*
> - * x86_configure_nx() is called before parse_early_param() to detect
> - * whether hardware doesn't support NX (so that the early EHCI debug
> - * console setup can safely call set_fixmap()). It may then be called
> - * again from within noexec_setup() during parsing early parameters
> - * to honor the respective command line option.
> - */
> - x86_configure_nx();
> -
> - parse_early_param();
> -
> #ifdef CONFIG_MEMORY_HOTPLUG
> /*
> * Memory used by the kernel cannot be hot-removed because Linux
> --
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Ping for review..

Another way is move "efi_memblock_x86_reserve_range" to later code
Maybe below is better?

---
arch/x86/kernel/setup.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)

--- linux-x86.orig/arch/x86/kernel/setup.c
+++ linux-x86/arch/x86/kernel/setup.c
@@ -906,9 +906,6 @@ void __init setup_arch(char **cmdline_p)
set_bit(EFI_BOOT, &efi.flags);
set_bit(EFI_64BIT, &efi.flags);
}
-
- if (efi_enabled(EFI_BOOT))
- efi_memblock_x86_reserve_range();
#endif

x86_init.oem.arch_setup();
@@ -962,6 +959,8 @@ void __init setup_arch(char **cmdline_p)

parse_early_param();

+ if (efi_enabled(EFI_BOOT))
+ efi_memblock_x86_reserve_range();
#ifdef CONFIG_MEMORY_HOTPLUG
/*
* Memory used by the kernel cannot be hot-removed because Linux

Thanks
Dave