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

[Alan Modra]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=cedfc77485dbb566619dc1e2d729ce0a70d1a4ad

commit cedfc77485dbb566619dc1e2d729ce0a70d1a4ad
Author: Alan Modra <amodra@gmail.com>
Date:   Mon Dec 16 10:31:34 2019 +1030

    ubsan: bfin: left shift of negative value
    
    	* bfin-dis.c (fmtconst, fmtconst_val): Avoid signed overflow.

Diff:
---
 opcodes/ChangeLog  |  4 ++++
 opcodes/bfin-dis.c | 17 ++++++++---------
 2 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/opcodes/ChangeLog b/opcodes/ChangeLog
index 65ef685..ca47606 100644
--- a/opcodes/ChangeLog
+++ b/opcodes/ChangeLog
@@ -1,5 +1,9 @@
 2019-12-16  Alan Modra  <amodra@gmail.com>
 
+	* bfin-dis.c (fmtconst, fmtconst_val): Avoid signed overflow.
+
+2019-12-16  Alan Modra  <amodra@gmail.com>
+
 	* nds32-dis.c (print_insn16, print_insn32): Remove forward decls.
 	(struct objdump_disasm_info): Delete.
 	(nds32_parse_audio_ext, nds32_parse_opcode): Cast result of
diff --git a/opcodes/bfin-dis.c b/opcodes/bfin-dis.c
index 711f7e1..19ce426 100644
--- a/opcodes/bfin-dis.c
+++ b/opcodes/bfin-dis.c
@@ -128,7 +128,8 @@ fmtconst (const_forms_t cf, TIword x, bfd_vma pc, disassemble_info *outf)
 
       if (constant_formats[cf].pcrel)
 	x = SIGNEXTEND (x, constant_formats[cf].nbits);
-      ea = (x + constant_formats[cf].offset) << constant_formats[cf].scale;
+      ea = x + constant_formats[cf].offset;
+      ea = ea << constant_formats[cf].scale;
       if (constant_formats[cf].pcrel)
 	ea += pc;
 
@@ -152,17 +153,14 @@ fmtconst (const_forms_t cf, TIword x, bfd_vma pc, disassemble_info *outf)
     {
       int nb = constant_formats[cf].nbits + 1;
 
-      x = x | (1 << constant_formats[cf].nbits);
+      x = x | (1ul << constant_formats[cf].nbits);
       x = SIGNEXTEND (x, nb);
     }
   else if (constant_formats[cf].issigned)
     x = SIGNEXTEND (x, constant_formats[cf].nbits);
 
-  if (constant_formats[cf].offset)
-    x += constant_formats[cf].offset;
-
-  if (constant_formats[cf].scale)
-    x <<= constant_formats[cf].scale;
+  x += constant_formats[cf].offset;
+  x = (unsigned long) x << constant_formats[cf].scale;
 
   if (constant_formats[cf].decimal)
     sprintf (buf, "%*li", constant_formats[cf].leading, x);
@@ -186,7 +184,8 @@ fmtconst_val (const_forms_t cf, unsigned int x, unsigned int pc)
 
       if (constant_formats[cf].pcrel)
 	x = SIGNEXTEND (x, constant_formats[cf].nbits);
-      ea = (x + constant_formats[cf].offset) << constant_formats[cf].scale;
+      ea = x + constant_formats[cf].offset;
+      ea = ea << constant_formats[cf].scale;
       if (constant_formats[cf].pcrel)
 	ea += pc;
 
@@ -197,7 +196,7 @@ fmtconst_val (const_forms_t cf, unsigned int x, unsigned int pc)
   if (constant_formats[cf].negative)
     {
       int nb = constant_formats[cf].nbits + 1;
-      x = x | (1u << constant_formats[cf].nbits);
+      x = x | (1ul << constant_formats[cf].nbits);
       x = SIGNEXTEND (x, nb);
     }
   else if (constant_formats[cf].issigned)