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Commit 48fcb2d0 authored by Ard Biesheuvel's avatar Ard Biesheuvel Committed by Catalin Marinas
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efi: stub: use high allocation for converted command line 



Before we can move the command line processing before the allocation
of the kernel, which is required for detecting the 'nokaslr' option
which controls that allocation, move the converted command line higher
up in memory, to prevent it from interfering with the kernel itself.

Since x86 needs the address to fit in 32 bits, use UINT_MAX as the upper
bound there. Otherwise, use ULONG_MAX (i.e., no limit)

Reviewed-by: default avatarMatt Fleming <matt@codeblueprint.co.uk>
Signed-off-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent 2ddbfc81

arch/x86/include/asm/efi.h

+2 −0
Original line number Diff line number Diff line
@@ -25,6 +25,8 @@ 
#define EFI32_LOADER_SIGNATURE	"EL32"

#define EFI64_LOADER_SIGNATURE	"EL64"



#define MAX_CMDLINE_ADDRESS	UINT_MAX



#ifdef CONFIG_X86_32

drivers/firmware/efi/libstub/efi-stub-helper.c

+6 −1
Original line number Diff line number Diff line
@@ -649,6 +649,10 @@ static u8 *efi_utf16_to_utf8(u8 *dst, const u16 *src, int n) 
	return dst;

}



#ifndef MAX_CMDLINE_ADDRESS

#define MAX_CMDLINE_ADDRESS	ULONG_MAX

#endif



/*

 * Convert the unicode UEFI command line to ASCII to pass to kernel.

 * Size of memory allocated return in *cmd_line_len.
@@ -684,7 +688,8 @@ char *efi_convert_cmdline(efi_system_table_t *sys_table_arg, 


	options_bytes++;	/* NUL termination */



	status = efi_low_alloc(sys_table_arg, options_bytes, 0, &cmdline_addr);

	status = efi_high_alloc(sys_table_arg, options_bytes, 0,

				&cmdline_addr, MAX_CMDLINE_ADDRESS);

	if (status != EFI_SUCCESS)

		return NULL;