1 files changed, 24 insertions, 20 deletions

diff --git a/arch/x86/lib/insn-eval.c b/arch/x86/lib/insn-eval.c
index 2bf07e18e38c..a67afd74232c 100644
--- a/arch/x86/lib/insn-eval.c
+++ b/arch/x86/lib/insn-eval.c
@@ -404,10 +404,6 @@ static short get_segment_selector(struct pt_regs *regs, int seg_reg_idx)
 	case INAT_SEG_REG_FS:
 		return (unsigned short)(regs->fs & 0xffff);
 	case INAT_SEG_REG_GS:
-		/*
-		 * GS may or may not be in regs as per CONFIG_X86_32_LAZY_GS.
-		 * The macro below takes care of both cases.
-		 */
 		return get_user_gs(regs);
 	case INAT_SEG_REG_IGNORE:
 	default:
@@ -928,10 +924,11 @@ static int get_seg_base_limit(struct insn *insn, struct pt_regs *regs,
 static int get_eff_addr_reg(struct insn *insn, struct pt_regs *regs,
 			    int *regoff, long *eff_addr)
 {
-	insn_get_modrm(insn);
+	int ret;
 
-	if (!insn->modrm.nbytes)
-		return -EINVAL;
+	ret = insn_get_modrm(insn);
+	if (ret)
+		return ret;
 
 	if (X86_MODRM_MOD(insn->modrm.value) != 3)
 		return -EINVAL;
@@ -977,14 +974,14 @@ static int get_eff_addr_modrm(struct insn *insn, struct pt_regs *regs,
 			      int *regoff, long *eff_addr)
 {
 	long tmp;
+	int ret;
 
 	if (insn->addr_bytes != 8 && insn->addr_bytes != 4)
 		return -EINVAL;
 
-	insn_get_modrm(insn);
-
-	if (!insn->modrm.nbytes)
-		return -EINVAL;
+	ret = insn_get_modrm(insn);
+	if (ret)
+		return ret;
 
 	if (X86_MODRM_MOD(insn->modrm.value) > 2)
 		return -EINVAL;
@@ -1106,18 +1103,21 @@ static int get_eff_addr_modrm_16(struct insn *insn, struct pt_regs *regs,
  * @base_offset will have a register, as an offset from the base of pt_regs,
  * that can be used to resolve the associated segment.
  *
- * -EINVAL on error.
+ * Negative value on error.
  */
 static int get_eff_addr_sib(struct insn *insn, struct pt_regs *regs,
 			    int *base_offset, long *eff_addr)
 {
 	long base, indx;
 	int indx_offset;
+	int ret;
 
 	if (insn->addr_bytes != 8 && insn->addr_bytes != 4)
 		return -EINVAL;
 
-	insn_get_modrm(insn);
+	ret = insn_get_modrm(insn);
+	if (ret)
+		return ret;
 
 	if (!insn->modrm.nbytes)
 		return -EINVAL;
@@ -1125,7 +1125,9 @@ static int get_eff_addr_sib(struct insn *insn, struct pt_regs *regs,
 	if (X86_MODRM_MOD(insn->modrm.value) > 2)
 		return -EINVAL;
 
-	insn_get_sib(insn);
+	ret = insn_get_sib(insn);
+	if (ret)
+		return ret;
 
 	if (!insn->sib.nbytes)
 		return -EINVAL;
@@ -1194,8 +1196,8 @@ static void __user *get_addr_ref_16(struct insn *insn, struct pt_regs *regs)
 	short eff_addr;
 	long tmp;
 
-	insn_get_modrm(insn);
-	insn_get_displacement(insn);
+	if (insn_get_displacement(insn))
+		goto out;
 
 	if (insn->addr_bytes != 2)
 		goto out;
@@ -1492,7 +1494,7 @@ int insn_fetch_from_user_inatomic(struct pt_regs *regs, unsigned char buf[MAX_IN
 }
 
 /**
- * insn_decode() - Decode an instruction
+ * insn_decode_from_regs() - Decode an instruction
  * @insn:	Structure to store decoded instruction
  * @regs:	Structure with register values as seen when entering kernel mode
  * @buf:	Buffer containing the instruction bytes
@@ -1505,8 +1507,8 @@ int insn_fetch_from_user_inatomic(struct pt_regs *regs, unsigned char buf[MAX_IN
  *
  * True if instruction was decoded, False otherwise.
  */
-bool insn_decode(struct insn *insn, struct pt_regs *regs,
-		 unsigned char buf[MAX_INSN_SIZE], int buf_size)
+bool insn_decode_from_regs(struct insn *insn, struct pt_regs *regs,
+			   unsigned char buf[MAX_INSN_SIZE], int buf_size)
 {
 	int seg_defs;
 
@@ -1529,7 +1531,9 @@ bool insn_decode(struct insn *insn, struct pt_regs *regs,
 	insn->addr_bytes = INSN_CODE_SEG_ADDR_SZ(seg_defs);
 	insn->opnd_bytes = INSN_CODE_SEG_OPND_SZ(seg_defs);
 
-	insn_get_length(insn);
+	if (insn_get_length(insn))
+		return false;
+
 	if (buf_size < insn->length)
 		return false;