From 48fcb2d0216103d15306caa4814e2381104df6d8 Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Mon, 11 Jan 2016 11:47:49 +0100 Subject: [PATCH] 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: Matt Fleming Signed-off-by: Ard Biesheuvel Signed-off-by: Catalin Marinas --- arch/x86/include/asm/efi.h | 2 ++ drivers/firmware/efi/libstub/efi-stub-helper.c | 7 ++++++- 2 files changed, 8 insertions(+), 1 deletion(-) diff --git a/arch/x86/include/asm/efi.h b/arch/x86/include/asm/efi.h index 0010c78c4998..08b1f2f6ea50 100644 --- a/arch/x86/include/asm/efi.h +++ b/arch/x86/include/asm/efi.h @@ -25,6 +25,8 @@ #define EFI32_LOADER_SIGNATURE "EL32" #define EFI64_LOADER_SIGNATURE "EL64" +#define MAX_CMDLINE_ADDRESS UINT_MAX + #ifdef CONFIG_X86_32 diff --git a/drivers/firmware/efi/libstub/efi-stub-helper.c b/drivers/firmware/efi/libstub/efi-stub-helper.c index f07d4a67fa76..29ed2f9b218c 100644 --- a/drivers/firmware/efi/libstub/efi-stub-helper.c +++ b/drivers/firmware/efi/libstub/efi-stub-helper.c @@ -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;