[binutils-gdb] ubsan: moxie: left shift of negative value

[Alan Modra]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=8c9b4171877df495a55b75365203258785da0041

commit 8c9b4171877df495a55b75365203258785da0041
Author: Alan Modra <amodra@gmail.com>
Date:   Wed Dec 11 08:26:58 2019 +1030

    ubsan: moxie: left shift of negative value
    
    	* moxie-dis.c (INST2OFFSET): Don't sign extend using shifts.

Diff:
---
 opcodes/ChangeLog   | 4 ++++
 opcodes/moxie-dis.c | 2 +-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/opcodes/ChangeLog b/opcodes/ChangeLog
index ffe57a4..60dfe76 100644
--- a/opcodes/ChangeLog
+++ b/opcodes/ChangeLog
@@ -1,5 +1,9 @@
 2019-12-11  Alan Modra  <amodra@gmail.com>
 
+	* moxie-dis.c (INST2OFFSET): Don't sign extend using shifts.
+
+2019-12-11  Alan Modra  <amodra@gmail.com>
+
 	* m68k-dis.c (COERCE32): Cast value first.
 	(NEXTLONG, NEXTULONG): Avoid signed overflow.
 
diff --git a/opcodes/moxie-dis.c b/opcodes/moxie-dis.c
index 3097fa0..cbfcf95 100644
--- a/opcodes/moxie-dis.c
+++ b/opcodes/moxie-dis.c
@@ -33,7 +33,7 @@ static void *stream;
 /* Macros to extract operands from the instruction word.  */
 #define OP_A(i) ((i >> 4) & 0xf)
 #define OP_B(i) (i & 0xf)
-#define INST2OFFSET(o) ((((signed short)((o & ((1<<10)-1))<<6))>>6)<<1)
+#define INST2OFFSET(o) (((((o) & 0x3ff) ^ 0x200) - 0x200) << 1)
 
 static const char * reg_names[16] =
   { "$fp", "$sp", "$r0", "$r1", "$r2", "$r3", "$r4", "$r5",