From: liuzhensong <liuzhensong@loongson.cn>
To: binutils@sourceware.org
Cc: liuzhensong <liuzhensong@loongson.cn>
Subject: [PATCH] ubsan: loongarch : signed integer shift overflow.
Date: Sat, 12 Mar 2022 15:40:39 +0800 [thread overview]
Message-ID: <20220312074039.3808325-1-liuzhensong@loongson.cn> (raw)
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
reply other threads:[~2022-03-12 7:40 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20220312074039.3808325-1-liuzhensong@loongson.cn \
--to=liuzhensong@loongson.cn \
--cc=binutils@sourceware.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).