diff options
Diffstat (limited to 'arch/x86/lib')
| -rw-r--r-- | arch/x86/lib/copy_user_64.S | 4 | ||||
| -rw-r--r-- | arch/x86/lib/insn-eval.c | 109 |
2 files changed, 109 insertions, 4 deletions
diff --git a/arch/x86/lib/copy_user_64.S b/arch/x86/lib/copy_user_64.S index 2797e630b9b1..1c429f0489dd 100644 --- a/arch/x86/lib/copy_user_64.S +++ b/arch/x86/lib/copy_user_64.S @@ -200,8 +200,8 @@ EXPORT_SYMBOL(copy_user_generic_string) */ SYM_FUNC_START(copy_user_enhanced_fast_string) ASM_STAC - cmpl $64,%edx - jb .L_copy_short_string /* less then 64 bytes, avoid the costly 'rep' */ + /* CPUs without FSRM should avoid rep movsb for short copies */ + ALTERNATIVE "cmpl $64, %edx; jb .L_copy_short_string", "", X86_FEATURE_FSRM movl %edx,%ecx 1: rep movsb diff --git a/arch/x86/lib/insn-eval.c b/arch/x86/lib/insn-eval.c index eb3ccffb9b9d..53e57ef5925c 100644 --- a/arch/x86/lib/insn-eval.c +++ b/arch/x86/lib/insn-eval.c @@ -37,8 +37,6 @@ enum reg_type { */ static bool is_string_insn(struct insn *insn) { - insn_get_opcode(insn); - /* All string instructions have a 1-byte opcode. */ if (insn->opcode.nbytes != 1) return false; @@ -851,6 +849,26 @@ int insn_get_modrm_reg_off(struct insn *insn, struct pt_regs *regs) } /** + * insn_get_modrm_reg_ptr() - Obtain register pointer based on ModRM byte + * @insn: Instruction containing the ModRM byte + * @regs: Register values as seen when entering kernel mode + * + * Returns: + * + * The register indicated by the reg part of the ModRM byte. + * The register is obtained as a pointer within pt_regs. + */ +unsigned long *insn_get_modrm_reg_ptr(struct insn *insn, struct pt_regs *regs) +{ + int offset; + + offset = insn_get_modrm_reg_off(insn, regs); + if (offset < 0) + return NULL; + return (void *)regs + offset; +} + +/** * get_seg_base_limit() - obtain base address and limit of a segment * @insn: Instruction. Must be valid. * @regs: Register values as seen when entering kernel mode @@ -1405,6 +1423,9 @@ void __user *insn_get_addr_ref(struct insn *insn, struct pt_regs *regs) if (!insn || !regs) return (void __user *)-1L; + if (insn_get_opcode(insn)) + return (void __user *)-1L; + switch (insn->addr_bytes) { case 2: return get_addr_ref_16(insn, regs); @@ -1539,3 +1560,87 @@ bool insn_decode_from_regs(struct insn *insn, struct pt_regs *regs, return true; } + +/** + * insn_decode_mmio() - Decode a MMIO instruction + * @insn: Structure to store decoded instruction + * @bytes: Returns size of memory operand + * + * Decodes instruction that used for Memory-mapped I/O. + * + * Returns: + * + * Type of the instruction. Size of the memory operand is stored in + * @bytes. If decode failed, MMIO_DECODE_FAILED returned. + */ +enum mmio_type insn_decode_mmio(struct insn *insn, int *bytes) +{ + enum mmio_type type = MMIO_DECODE_FAILED; + + *bytes = 0; + + if (insn_get_opcode(insn)) + return MMIO_DECODE_FAILED; + + switch (insn->opcode.bytes[0]) { + case 0x88: /* MOV m8,r8 */ + *bytes = 1; + fallthrough; + case 0x89: /* MOV m16/m32/m64, r16/m32/m64 */ + if (!*bytes) + *bytes = insn->opnd_bytes; + type = MMIO_WRITE; + break; + + case 0xc6: /* MOV m8, imm8 */ + *bytes = 1; + fallthrough; + case 0xc7: /* MOV m16/m32/m64, imm16/imm32/imm64 */ + if (!*bytes) + *bytes = insn->opnd_bytes; + type = MMIO_WRITE_IMM; + break; + + case 0x8a: /* MOV r8, m8 */ + *bytes = 1; + fallthrough; + case 0x8b: /* MOV r16/r32/r64, m16/m32/m64 */ + if (!*bytes) + *bytes = insn->opnd_bytes; + type = MMIO_READ; + break; + + case 0xa4: /* MOVS m8, m8 */ + *bytes = 1; + fallthrough; + case 0xa5: /* MOVS m16/m32/m64, m16/m32/m64 */ + if (!*bytes) + *bytes = insn->opnd_bytes; + type = MMIO_MOVS; + break; + + case 0x0f: /* Two-byte instruction */ + switch (insn->opcode.bytes[1]) { + case 0xb6: /* MOVZX r16/r32/r64, m8 */ + *bytes = 1; + fallthrough; + case 0xb7: /* MOVZX r32/r64, m16 */ + if (!*bytes) + *bytes = 2; + type = MMIO_READ_ZERO_EXTEND; + break; + + case 0xbe: /* MOVSX r16/r32/r64, m8 */ + *bytes = 1; + fallthrough; + case 0xbf: /* MOVSX r32/r64, m16 */ + if (!*bytes) + *bytes = 2; + type = MMIO_READ_SIGN_EXTEND; + break; + } + break; + } + + return type; +} |