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Diffstat (limited to 'arch/x86/lib/insn-eval.c')
-rw-r--r--arch/x86/lib/insn-eval.c180
1 files changed, 154 insertions, 26 deletions
diff --git a/arch/x86/lib/insn-eval.c b/arch/x86/lib/insn-eval.c
index eb3ccffb9b9d..b781d324211b 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;
@@ -412,32 +410,44 @@ static short get_segment_selector(struct pt_regs *regs, int seg_reg_idx)
#endif /* CONFIG_X86_64 */
}
-static int get_reg_offset(struct insn *insn, struct pt_regs *regs,
- enum reg_type type)
+static const int pt_regoff[] = {
+ offsetof(struct pt_regs, ax),
+ offsetof(struct pt_regs, cx),
+ offsetof(struct pt_regs, dx),
+ offsetof(struct pt_regs, bx),
+ offsetof(struct pt_regs, sp),
+ offsetof(struct pt_regs, bp),
+ offsetof(struct pt_regs, si),
+ offsetof(struct pt_regs, di),
+#ifdef CONFIG_X86_64
+ offsetof(struct pt_regs, r8),
+ offsetof(struct pt_regs, r9),
+ offsetof(struct pt_regs, r10),
+ offsetof(struct pt_regs, r11),
+ offsetof(struct pt_regs, r12),
+ offsetof(struct pt_regs, r13),
+ offsetof(struct pt_regs, r14),
+ offsetof(struct pt_regs, r15),
+#else
+ offsetof(struct pt_regs, ds),
+ offsetof(struct pt_regs, es),
+ offsetof(struct pt_regs, fs),
+ offsetof(struct pt_regs, gs),
+#endif
+};
+
+int pt_regs_offset(struct pt_regs *regs, int regno)
+{
+ if ((unsigned)regno < ARRAY_SIZE(pt_regoff))
+ return pt_regoff[regno];
+ return -EDOM;
+}
+
+static int get_regno(struct insn *insn, enum reg_type type)
{
+ int nr_registers = ARRAY_SIZE(pt_regoff);
int regno = 0;
- static const int regoff[] = {
- offsetof(struct pt_regs, ax),
- offsetof(struct pt_regs, cx),
- offsetof(struct pt_regs, dx),
- offsetof(struct pt_regs, bx),
- offsetof(struct pt_regs, sp),
- offsetof(struct pt_regs, bp),
- offsetof(struct pt_regs, si),
- offsetof(struct pt_regs, di),
-#ifdef CONFIG_X86_64
- offsetof(struct pt_regs, r8),
- offsetof(struct pt_regs, r9),
- offsetof(struct pt_regs, r10),
- offsetof(struct pt_regs, r11),
- offsetof(struct pt_regs, r12),
- offsetof(struct pt_regs, r13),
- offsetof(struct pt_regs, r14),
- offsetof(struct pt_regs, r15),
-#endif
- };
- int nr_registers = ARRAY_SIZE(regoff);
/*
* Don't possibly decode a 32-bit instructions as
* reading a 64-bit-only register.
@@ -505,7 +515,18 @@ static int get_reg_offset(struct insn *insn, struct pt_regs *regs,
WARN_ONCE(1, "decoded an instruction with an invalid register");
return -EINVAL;
}
- return regoff[regno];
+ return regno;
+}
+
+static int get_reg_offset(struct insn *insn, struct pt_regs *regs,
+ enum reg_type type)
+{
+ int regno = get_regno(insn, type);
+
+ if (regno < 0)
+ return regno;
+
+ return pt_regs_offset(regs, regno);
}
/**
@@ -851,6 +872,26 @@ 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 +1446,9 @@ 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 +1583,87 @@ 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;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-29 19:40:53 +0000