perf/x86/intel/ds: Check return values of insn decoder functions

branch_type() doesn't need to call the full insn_decode() because it
doesn't need it in all cases thus leave the calls separate.
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210304174237.31945-9-bp@alien8.de

arch/x86/events/intel/lbr.c

@@ -1224,8 +1224,7 @@ static int branch_type(unsigned long from, unsigned long to, int abort)
 	is64 = kernel_ip((unsigned long)addr) || any_64bit_mode(current_pt_regs());
 #endif
 	insn_init(&insn, addr, bytes_read, is64);
-	insn_get_opcode(&insn);
-	if (!insn.opcode.got)
+	if (insn_get_opcode(&insn))
 		return X86_BR_ABORT;
 
 	switch (insn.opcode.bytes[0]) {
@@ -1262,8 +1261,7 @@ static int branch_type(unsigned long from, unsigned long to, int abort)
 		ret = X86_BR_INT;
 		break;
 	case 0xe8: /* call near rel */
-		insn_get_immediate(&insn);
-		if (insn.immediate1.value == 0) {
+		if (insn_get_immediate(&insn) || insn.immediate1.value == 0) {
 			/* zero length call */
 			ret = X86_BR_ZERO_CALL;
 			break;
@@ -1279,7 +1277,9 @@ static int branch_type(unsigned long from, unsigned long to, int abort)
 		ret = X86_BR_JMP;
 		break;
 	case 0xff: /* call near absolute, call far absolute ind */
-		insn_get_modrm(&insn);
+		if (insn_get_modrm(&insn))
+			return X86_BR_ABORT;
+
 		ext = (insn.modrm.bytes[0] >> 3) & 0x7;
 		switch (ext) {
 		case 2: /* near ind call */