From e36144c932b0ad0de4774b8bb2552178e4f2f2a6 Mon Sep 17 00:00:00 2001 From: liuzhensong Date: Tue, 16 Nov 2021 19:15:29 +0800 Subject: [PATCH] ubsan: loongarch : signed integer shift overflow. opcodes/ * loongarch-coder.c : int32_t ret = 0; ret <<= sizeof (ret) * 8 - len; ret >>= sizeof (ret) * 8 - len; ... Avoid ubsan warning. --- opcodes/loongarch-coder.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/opcodes/loongarch-coder.c b/opcodes/loongarch-coder.c index cb6d5648da0..c957b95df74 100644 --- a/opcodes/loongarch-coder.c +++ b/opcodes/loongarch-coder.c @@ -106,11 +106,13 @@ loongarch_decode_imm (const char *bit_field, insn_t insn, int si) else if (*bit_field_1 == '+') ret += atoi (bit_field_1 + 1); + /* Extend signed bit. */ if (si) { - ret <<= sizeof (ret) * 8 - len; - ret >>= sizeof (ret) * 8 - len; + uint32_t sign = 1u << (len - 1); + ret = (ret ^ sign) - sign; } + return ret; } @@ -133,7 +135,8 @@ loongarch_encode_imm (const char *bit_field, int32_t imm) else if (*t == '+') uimm -= atoi (t + 1); - uimm <<= sizeof (uimm) * 8 - width; + uimm = width ? (uimm << (sizeof (uimm) * 8 - width)) : 0; + while (1) { b_start = strtol (bit_field_1, &bit_field_1, 10); @@ -141,10 +144,10 @@ loongarch_encode_imm (const char *bit_field, int32_t imm) break; width = strtol (bit_field_1 + 1, &bit_field_1, 10); i = uimm; - i >>= sizeof (i) * 8 - width; - i <<= b_start; + i = width ? (i >> (sizeof (i) * 8 - width)) : 0; + i = (b_start == 32) ? 0 : (i << b_start); ret |= i; - uimm <<= width; + uimm = (width == 32) ? 0 : (uimm << width); if (*bit_field_1 != '|') break; -- 2.30.2