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authorTom de Vries <tdevries@suse.de>2022-05-23 14:50:02 +0200
committerTom de Vries <tdevries@suse.de>2022-05-23 14:50:02 +0200
commit5a3cf18c2ed9593f194ea22f50ea5651532f6cfc (patch)
tree4b617189ef5761bb5f892e09774bedf49865dc52 /gdb/valarith.c
parent05527d8ca1082b4607e9ddc3209691f454b3b186 (diff)
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[gdb/exp] Fix UB in scalar_binop
When building gdb with -fsanitize=undefined, I run into: ... $ gdb -q -batch -ex "p -(-0x7fffffffffffffff - 1)" src/gdb/valarith.c:1385:10: runtime error: signed integer overflow: \ 0 - -9223372036854775808 cannot be represented in type 'long int' $1 = -9223372036854775808 ... Fix this by performing the substraction in scalar_binop using unsigned types. Tested on x86_64-linux.
Diffstat (limited to 'gdb/valarith.c')
-rw-r--r--gdb/valarith.c5
1 files changed, 4 insertions, 1 deletions
diff --git a/gdb/valarith.c b/gdb/valarith.c
index 6210267..526cc02 100644
--- a/gdb/valarith.c
+++ b/gdb/valarith.c
@@ -1382,7 +1382,10 @@ scalar_binop (struct value *arg1, struct value *arg2, enum exp_opcode op)
break;
case BINOP_SUB:
- v = v1 - v2;
+ /* Avoid runtime error: signed integer overflow: \
+ 0 - -9223372036854775808 cannot be represented in type
+ 'long int'. */
+ v = (ULONGEST)v1 - (ULONGEST)v2;
break;
case BINOP_MUL: