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author | Mark Brown <broonie@kernel.org> | 2018-01-08 15:54:50 +0000 |
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committer | Mark Brown <broonie@kernel.org> | 2018-01-08 15:54:50 +0000 |
commit | 498495dba268b20e8eadd7fe93c140c68b6cc9d2 (patch) | |
tree | 00d1562049d8bc2194fddd9ba0cbbe0812ad6f68 /arch/x86/mm/kmemcheck/opcode.c | |
parent | d5cc0a1fcbb5ddbef9fdd4c4a978da3254ddbf37 (diff) | |
parent | 5c256045b87b8aa8e5bc9d2e2fdc0802351c1f99 (diff) | |
download | linux-stable-498495dba268b20e8eadd7fe93c140c68b6cc9d2.tar.gz linux-stable-498495dba268b20e8eadd7fe93c140c68b6cc9d2.tar.bz2 linux-stable-498495dba268b20e8eadd7fe93c140c68b6cc9d2.zip |
Merge branch 'fix/intel' of https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound into asoc-intel
Diffstat (limited to 'arch/x86/mm/kmemcheck/opcode.c')
-rw-r--r-- | arch/x86/mm/kmemcheck/opcode.c | 107 |
1 files changed, 1 insertions, 106 deletions
diff --git a/arch/x86/mm/kmemcheck/opcode.c b/arch/x86/mm/kmemcheck/opcode.c index 324aa3f07237..cec594032515 100644 --- a/arch/x86/mm/kmemcheck/opcode.c +++ b/arch/x86/mm/kmemcheck/opcode.c @@ -1,106 +1 @@ -#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; -} +// SPDX-License-Identifier: GPL-2.0 |