[binutils-gdb] Prevent a left shift by a negative value when disassembling IA64 binaries.

[Nick Clifton]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=993a00a986d0795a3cbb7a2dd0c640d8e6d66734

commit 993a00a986d0795a3cbb7a2dd0c640d8e6d66734
Author: Nick Clifton <nickc@redhat.com>
Date:   Tue Oct 29 10:01:27 2019 +0000

    Prevent a left shift by a negative value when disassembling IA64 binaries.
    
    	* ia64-opc.c (locate_opcode_ent): Prevent a negative shift when
    	locating the bit to be tested.

Diff:
---
 opcodes/ChangeLog  | 5 +++++
 opcodes/ia64-opc.c | 9 ++++++---
 2 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/opcodes/ChangeLog b/opcodes/ChangeLog
index d83b5ba..d596729 100644
--- a/opcodes/ChangeLog
+++ b/opcodes/ChangeLog
@@ -1,5 +1,10 @@
 2019-10-29  Nick Clifton  <nickc@redhat.com>
 
+	* ia64-opc.c (locate_opcode_ent): Prevent a negative shift when
+	locating the bit to be tested.
+
+2019-10-29  Nick Clifton  <nickc@redhat.com>
+
 	* s12z-dis.c (opr_emit_disassembly): Check for illegal register
 	values.
 	(shift_size_table): Use a fixed size defined as S12Z_N_SIZES.
diff --git a/opcodes/ia64-opc.c b/opcodes/ia64-opc.c
index 5aa1198..ba60f8a 100644
--- a/opcodes/ia64-opc.c
+++ b/opcodes/ia64-opc.c
@@ -372,13 +372,16 @@ locate_opcode_ent (ia64_insn opcode, enum ia64_insn_type type)
 
       bitpos[currstatenum] = currbitnum;
 
-      /* Skip opval[0] bits in the instruction. */
+      /* Skip opval[0] bits in the instruction.  */
       if (op & 0x40)
 	{
 	  currbitnum -= opval[0];
 	}
 
-      /* The value of the current bit being tested. */
+      if (currbitnum < 0)
+	currbitnum = 0;
+
+      /* The value of the current bit being tested.  */
       currbit = opcode & (((ia64_insn) 1) << currbitnum) ? 1 : 0;
       next_op = -1;
 
@@ -463,7 +466,7 @@ locate_opcode_ent (ia64_insn opcode, enum ia64_insn_type type)
 
 	  if (next_op > 65535)
 	    {
-	      abort ();
+	      return -1;
 	    }
 
 	  /* Run through the list of opcodes to check, trying to find