From: Simon Marchi <simon.marchi@polymtl.ca>
To: gdb-patches@sourceware.org
Subject: [PATCH] gdb: fix nr_bits gdb_assert in append_flags_type_field
Date: Fri, 23 Jul 2021 00:32:23 -0400 [thread overview]
Message-ID: <20210723043223.1980356-1-simon.marchi@polymtl.ca> (raw)
The assertion
gdb_assert (nr_bits >= 1 && nr_bits <= type_bitsize);
is not correct. Well, it's correct in that we do want the number of
bits to be in the range [1, type_bitsize]. But we don't check anywhere
that the end of the specified flag is within the containing type.
The following code should generate a failed assertion, as the flag goes
past the 32 bits of the underlying type, but it's currently not caught:
static void
test_print_flag (gdbarch *arch)
{
type *flags_type = arch_flags_type (arch, "test_type", 32);
type *field_type = builtin_type (arch)->builtin_uint32;
append_flags_type_field (flags_type, 31, 2, field_type, "invalid");
}
(You can test this by registering it as a selftest using
selftests::register_test_foreach_arc and running.)
Change the assertion to verify that the end bit is within the range of
the underlying type. This implicitly verifies that nr_bits is not
too big as well, so we don't need a separate assertion for that.
Change-Id: I9be79e5fd7a5917bf25b03b598727e6274c892e8
Co-Authored-By: Tony Tye <Tony.Tye@amd.com>
---
gdb/gdbtypes.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/gdb/gdbtypes.c b/gdb/gdbtypes.c
index 1a261719422a..85c9df0e2c6d 100644
--- a/gdb/gdbtypes.c
+++ b/gdb/gdbtypes.c
@@ -5825,7 +5825,7 @@ append_flags_type_field (struct type *type, int start_bitpos, int nr_bits,
gdb_assert (type->code () == TYPE_CODE_FLAGS);
gdb_assert (type->num_fields () + 1 <= type_bitsize);
gdb_assert (start_bitpos >= 0 && start_bitpos < type_bitsize);
- gdb_assert (nr_bits >= 1 && nr_bits <= type_bitsize);
+ gdb_assert (nr_bits >= 1 && (start_bitpos + nr_bits) <= type_bitsize);
gdb_assert (name != NULL);
TYPE_FIELD_NAME (type, field_nr) = xstrdup (name);
--
2.32.0
next reply other threads:[~2021-07-23 4:32 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-23 4:32 Simon Marchi [this message]
2021-07-29 20:04 ` Tom Tromey
2021-07-30 1:59 ` Simon Marchi
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=20210723043223.1980356-1-simon.marchi@polymtl.ca \
--to=simon.marchi@polymtl.ca \
--cc=gdb-patches@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).