From 487b0ff02ddafeb27641c7674d4c8b3c9f62c6c3 Mon Sep 17 00:00:00 2001 From: Alan Modra Date: Sat, 1 Jan 2022 13:52:53 +1030 Subject: [PATCH] ubsan: signed integer multiply overflow 9223371018427387904 * 2 cannot be represented in type 'long', yes, but we don't care. * expr.c (expr): Avoid signed overflow. --- gas/expr.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/gas/expr.c b/gas/expr.c index 03caa91f4d1..618927a605f 100644 --- a/gas/expr.c +++ b/gas/expr.c @@ -1959,7 +1959,12 @@ expr (int rankarg, /* Larger # is higher rank. */ switch (op_left) { default: goto general; - case O_multiply: resultP->X_add_number *= v; break; + case O_multiply: + /* Do the multiply as unsigned to silence ubsan. The + result is of course the same when we throw away high + bits of the result. */ + resultP->X_add_number *= (valueT) v; + break; case O_divide: resultP->X_add_number /= v; break; case O_modulus: resultP->X_add_number %= v; break; case O_left_shift: -- 2.30.2