* [PATCH] ubsan: loongarch : signed integer shift overflow.
@ 2022-03-12 7:40 liuzhensong
0 siblings, 0 replies; only message in thread
From: liuzhensong @ 2022-03-12 7:40 UTC (permalink / raw)
To: binutils; +Cc: liuzhensong
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;
--
2.31.1
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2022-03-12 7:40 [PATCH] ubsan: loongarch : signed integer shift overflow liuzhensong
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