From: H. Peter Anvin <hpa@xxxxxxxxx> The 64-bit code already clears EFLAGS as soon as it has a stack. This seems like a reasonable precaution, so do it on 32 bits as well. [ Impact: extra paranoia ] Signed-off-by: H. Peter Anvin <hpa at zytor.com> --- arch/x86/boot/compressed/head_32.S | 10 ++++++++-- 1 files changed, 8 insertions(+), 2 deletions(-) diff --git a/arch/x86/boot/compressed/head_32.S b/arch/x86/boot/compressed/head_32.S index 47636b3..48c2047 100644 --- a/arch/x86/boot/compressed/head_32.S +++ b/arch/x86/boot/compressed/head_32.S @@ -12,9 +12,9 @@ * the page directory. [According to comments etc elsewhere on a compressed * kernel it will end up at 0x1000 + 1Mb I hope so as I assume this. - AC] * - * Page 0 is deliberately kept safe, since System Management Mode code in + * Page 0 is deliberately kept safe, since System Management Mode code in * laptops may need to access the BIOS data stored there. This is also - * useful for future device drivers that either access the BIOS via VM86 + * useful for future device drivers that either access the BIOS via VM86 * mode. */ @@ -84,6 +84,12 @@ ENTRY(startup_32) leal boot_stack_end(%ebx), %esp /* + * Zero EFLAGS + */ + pushl $0 + popfl + +/* * Copy the compressed kernel to the end of our buffer * where decompression in place becomes safe. */ -- 1.6.0.6
