From 98b228f55014870092c15d7d168fecac69f2f12a Mon Sep 17 00:00:00 2001 From: Roy Franz Date: Wed, 15 Apr 2015 16:32:24 -0700 Subject: [PATCH] x86/efi: Store upper bits of command line buffer address in ext_cmd_line_ptr Until now, the EFI stub was only setting the 32 bit cmd_line_ptr in the setup_header structure, so on 64 bit platforms this could be truncated. This patch adds setting the upper bits of the buffer address in ext_cmd_line_ptr. This case was likely never hit, as the allocation for this buffer is done at the lowest available address. Only x86_64 kernels have this problem, as the 1-1 mapping mandated by EFI ensures that all memory is 32 bit addressable on 32 bit platforms. The EFI stub does not support mixed mode, so the 32 bit kernel on 64 bit firmware case does not need to be handled. Signed-off-by: Roy Franz Cc: Signed-off-by: Matt Fleming --- arch/x86/boot/compressed/eboot.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c index 92b9a5f2aed6..5999980206bf 100644 --- a/arch/x86/boot/compressed/eboot.c +++ b/arch/x86/boot/compressed/eboot.c @@ -1110,6 +1110,8 @@ struct boot_params *make_boot_params(struct efi_config *c) if (!cmdline_ptr) goto fail; hdr->cmd_line_ptr = (unsigned long)cmdline_ptr; + /* Fill in upper bits of command line address, NOP on 32 bit */ + boot_params->ext_cmd_line_ptr = (u64)(unsigned long)cmdline_ptr >> 32; hdr->ramdisk_image = 0; hdr->ramdisk_size = 0; -- 2.20.1