linux-sg2042/arch/x86/boot
Kirill A. Shutemov 45b13b424f x86/boot/compressed/64: Do not corrupt EDX on EFER.LME=1 setting
RDMSR in the trampoline code overwrites EDX but that register is used
to indicate whether 5-level paging has to be enabled and if clobbered,
leads to failure to boot on a 5-level paging machine.

Preserve EDX on the stack while we are dealing with EFER.

Fixes: b677dfae5a ("x86/boot/compressed/64: Set EFER.LME=1 in 32-bit trampoline before returning to long mode")
Reported-by: Kyle D Pelton <kyle.d.pelton@intel.com>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: dave.hansen@linux.intel.com
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Wei Huang <wei@redhat.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190206115253.1907-1-kirill.shutemov@linux.intel.com
2019-02-06 18:56:18 +01:00
..
compressed x86/boot/compressed/64: Do not corrupt EDX on EFER.LME=1 setting 2019-02-06 18:56:18 +01:00
tools
.gitignore
Makefile
a20.c
apm.c
bioscall.S
bitops.h
boot.h
cmdline.c
code16gcc.h
copy.S
cpu.c
cpucheck.c
cpuflags.c
cpuflags.h
ctype.h
early_serial_console.c
edd.c
genimage.sh
header.S
install.sh
main.c
memory.c
mkcpustr.c
mtools.conf.in
pm.c
pmjump.S
printf.c
regs.c
setup.ld
string.c
string.h
tty.c
version.c
vesa.h
video-bios.c
video-mode.c
video-vesa.c
video-vga.c
video.c
video.h