From: Jan Stancek <jstancek@redhat.com>
Date: Mon, 24 Aug 2015 13:50:15 +0000 (+0100)
Subject: Fix the partial disassembly of a broken three byte instruction at the end of a function.
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=5f40e14d768b94f7fdc050aeba5ee62e6a8d5756;p=binutils-gdb.git

Fix the partial disassembly of a broken three byte instruction at the end of a function.

opcodes	* i386-dis.c (print_insn): Fix decoding of three byte operands.

tests	* gas/i386/intel.s: Add test of disassembly of a potential
	three byte instuction at the end of a function.
	* gas/i386/intel.d: Update expected disassembly.
---

diff --git a/gas/testsuite/ChangeLog b/gas/testsuite/ChangeLog
index 2951966c0a2..6b852496958 100644
--- a/gas/testsuite/ChangeLog
+++ b/gas/testsuite/ChangeLog
@@ -1,3 +1,9 @@
+2015-08-24  Jan Stancek  <jstancek@redhat.com>
+
+	* gas/i386/intel.s: Add test of disassembly of a potential
+	three byte instuction at the end of a function.
+	* gas/i386/intel.d: Update expected disassembly.
+
 2015-08-21  Nick Clifton  <nickc@redhat.com>
 
 	PR gas/18581
diff --git a/gas/testsuite/gas/i386/intel.d b/gas/testsuite/gas/i386/intel.d
index 45a66a5e41f..d10b4f00bb4 100644
--- a/gas/testsuite/gas/i386/intel.d
+++ b/gas/testsuite/gas/i386/intel.d
@@ -698,4 +698,8 @@ Disassembly of section .text:
 [ 	]*[a-f0-9]+:	0f 4b 90 90 90 90 90 	cmovnp -0x6f6f6f70\(%eax\),%edx
 [ 	]*[a-f0-9]+:	66 0f 4a 90 90 90 90 90 	cmovp  -0x6f6f6f70\(%eax\),%dx
 [ 	]*[a-f0-9]+:	66 0f 4b 90 90 90 90 90 	cmovnp -0x6f6f6f70\(%eax\),%dx
+[ 	]*[a-f0-9]+:	24 2f                	and    \$0x2f,%al
+[ 	]*[a-f0-9]+:	0f                   	\.byte 0xf
+[a-f0-9]+ <barn>:
+[ 	]*[a-f0-9]+:	0f ba e2 03          	bt     \$0x3,%edx
 #pass
diff --git a/gas/testsuite/gas/i386/intel.s b/gas/testsuite/gas/i386/intel.s
index a3a07b336a4..045d6ae0fd0 100644
--- a/gas/testsuite/gas/i386/intel.s
+++ b/gas/testsuite/gas/i386/intel.s
@@ -698,3 +698,14 @@ fidivr  dword ptr [ebx]
  cmovpo edx, 0x90909090[eax]
  cmovpe  dx, 0x90909090[eax]
  cmovpo dx, 0x90909090[eax]
+
+	# Test that disassembly of a partial instruction shows the partial byte:
+	# https://www.sourceware.org/ml/binutils/2015-08/msg00226.html
+	.byte 0x24
+	.byte 0x2f
+	.byte 0x0f
+barn:
+        .byte 0x0f
+        .byte 0xba
+        .byte 0xe2
+        .byte 0x03
diff --git a/opcodes/ChangeLog b/opcodes/ChangeLog
index 89e150fa42d..3529dbc66a1 100644
--- a/opcodes/ChangeLog
+++ b/opcodes/ChangeLog
@@ -1,3 +1,7 @@
+2015-08-24  Jan Stancek  <jstancek@redhat.com>
+
+	* i386-dis.c (print_insn): Fix decoding of three byte operands.
+
 2015-08-21  Alexander Fomin  <alexander.fomin@intel.com>
 
 	PR binutils/18257
diff --git a/opcodes/i386-dis.c b/opcodes/i386-dis.c
index 055b38f9863..ae18cf2dee0 100644
--- a/opcodes/i386-dis.c
+++ b/opcodes/i386-dis.c
@@ -13438,8 +13438,10 @@ print_insn (bfd_vma pc, disassemble_info *info)
   if (*codep == 0x0f)
     {
       unsigned char threebyte;
-      FETCH_DATA (info, codep + 2);
-      threebyte = *++codep;
+
+      codep++;
+      FETCH_DATA (info, codep + 1);
+      threebyte = *codep;
       dp = &dis386_twobyte[threebyte];
       need_modrm = twobyte_has_modrm[*codep];
       codep++;