3rd-party/linux-kernel-module-cheat
1
0
Fork 0
mirror of https://github.com/cirosantilli/linux-kernel-module-cheat.git synced 2026-01-30 05:24:25 +01:00
Code Issues Releases Wiki Activity

x86 asm: move rotation and bit instructoins in from x86-assembly-cheat

Browse Source
This commit is contained in:
Ciro Santilli 六四事件 法轮功
2019-06-16 00:00:03 +00:00
parent 89084d2332
commit 658ac53d0f
10 changed files with 313 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

24
userland/arch/x86_64/sal.S Normal file
View File

@@ -0,0 +1,24 @@
/* https://github.com/cirosantilli/linux-kernel-module-cheat#x86-shift-and-rotate-instructions */
#include <lkmc.h>
LKMC_PROLOGUE
/* 0xFF == -1 in 2's complement with 8-bits. */
mov $0xFF, %r12
sal %r12b
LKMC_ASSERT(jc)
/* 0xFE == -2 in 2's complement with 8-bits. */
LKMC_ASSERT_EQ(%r12, $0xFE)
/* SAR*/
sar %r12b
LKMC_ASSERT(jnc)
/* -1 */
LKMC_ASSERT_EQ(%r12, $0xFF)
/* SAR rounds to -infinity: -1 goes to -1 again. */
sar %r12b
LKMC_ASSERT(jc)
/* -1 */
LKMC_ASSERT_EQ(%r12, $0xFF)
LKMC_EPILOGUE