diff options
author | Yunhong Jiang <yunhong.jiang@intel.com> | 2015-08-04 12:17:53 -0700 |
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committer | Yunhong Jiang <yunhong.jiang@intel.com> | 2015-08-04 15:44:42 -0700 |
commit | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch) | |
tree | 1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/arch/x86/mm/kmemcheck/opcode.c | |
parent | 98260f3884f4a202f9ca5eabed40b1354c489b29 (diff) |
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base.
It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:
commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Sat Jul 25 12:13:34 2015 +0200
Prepare v4.1.3-rt3
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.
Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/arch/x86/mm/kmemcheck/opcode.c')
-rw-r--r-- | kernel/arch/x86/mm/kmemcheck/opcode.c | 106 |
1 files changed, 106 insertions, 0 deletions
diff --git a/kernel/arch/x86/mm/kmemcheck/opcode.c b/kernel/arch/x86/mm/kmemcheck/opcode.c new file mode 100644 index 000000000..324aa3f07 --- /dev/null +++ b/kernel/arch/x86/mm/kmemcheck/opcode.c @@ -0,0 +1,106 @@ +#include <linux/types.h> + +#include "opcode.h" + +static bool opcode_is_prefix(uint8_t b) +{ + return + /* Group 1 */ + b == 0xf0 || b == 0xf2 || b == 0xf3 + /* Group 2 */ + || b == 0x2e || b == 0x36 || b == 0x3e || b == 0x26 + || b == 0x64 || b == 0x65 + /* Group 3 */ + || b == 0x66 + /* Group 4 */ + || b == 0x67; +} + +#ifdef CONFIG_X86_64 +static bool opcode_is_rex_prefix(uint8_t b) +{ + return (b & 0xf0) == 0x40; +} +#else +static bool opcode_is_rex_prefix(uint8_t b) +{ + return false; +} +#endif + +#define REX_W (1 << 3) + +/* + * This is a VERY crude opcode decoder. We only need to find the size of the + * load/store that caused our #PF and this should work for all the opcodes + * that we care about. Moreover, the ones who invented this instruction set + * should be shot. + */ +void kmemcheck_opcode_decode(const uint8_t *op, unsigned int *size) +{ + /* Default operand size */ + int operand_size_override = 4; + + /* prefixes */ + for (; opcode_is_prefix(*op); ++op) { + if (*op == 0x66) + operand_size_override = 2; + } + + /* REX prefix */ + if (opcode_is_rex_prefix(*op)) { + uint8_t rex = *op; + + ++op; + if (rex & REX_W) { + switch (*op) { + case 0x63: + *size = 4; + return; + case 0x0f: + ++op; + + switch (*op) { + case 0xb6: + case 0xbe: + *size = 1; + return; + case 0xb7: + case 0xbf: + *size = 2; + return; + } + + break; + } + + *size = 8; + return; + } + } + + /* escape opcode */ + if (*op == 0x0f) { + ++op; + + /* + * This is move with zero-extend and sign-extend, respectively; + * we don't have to think about 0xb6/0xbe, because this is + * already handled in the conditional below. + */ + if (*op == 0xb7 || *op == 0xbf) + operand_size_override = 2; + } + + *size = (*op & 1) ? operand_size_override : 1; +} + +const uint8_t *kmemcheck_opcode_get_primary(const uint8_t *op) +{ + /* skip prefixes */ + while (opcode_is_prefix(*op)) + ++op; + if (opcode_is_rex_prefix(*op)) + ++op; + return op; +} |