From: "Joel Fernandes (Google)" <joel@joelfernandes.org>
To: linux-kernel@vger.kernel.org
Cc: kernel-team@android.com,
"Joel Fernandes (Google)" <joel@joelfernandes.org>,
dancol@google.com, minchan@kernel.org,
Al Viro <viro@zeniv.linux.org.uk>,
Andrew Morton <akpm@linux-foundation.org>,
gregkh@linuxfoundation.org,
"J. Bruce Fields" <bfields@fieldses.org>,
Jeff Layton <jlayton@kernel.org>,
John Stultz <john.stultz@linaro.org>,
jreck@google.com, linux-fsdevel@vger.kernel.org,
linux-kselftest@vger.kernel.org, linux-mm@kvack.org,
marcandre.lureau@redhat.com,
Mike Kravetz <mike.kravetz@oracle.com>,
Shuah Khan <shuah@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
tkjos@google.com
Subject: [PATCH v3 2/2] selftests/memfd: Add tests for F_SEAL_FS_WRITE seal
Date: Wed, 17 Oct 2018 23:59:08 -0700 [thread overview]
Message-ID: <20181018065908.254389-2-joel@joelfernandes.org> (raw)
In-Reply-To: <20181018065908.254389-1-joel@joelfernandes.org>
Add tests to verify sealing memfds with the F_SEAL_FS_WRITE works as
expected.
Cc: dancol@google.com
Cc: minchan@kernel.org
Reviewed-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
---
tools/testing/selftests/memfd/memfd_test.c | 74 ++++++++++++++++++++++
1 file changed, 74 insertions(+)
diff --git a/tools/testing/selftests/memfd/memfd_test.c b/tools/testing/selftests/memfd/memfd_test.c
index 10baa1652fc2..32b207ca7372 100644
--- a/tools/testing/selftests/memfd/memfd_test.c
+++ b/tools/testing/selftests/memfd/memfd_test.c
@@ -692,6 +692,79 @@ static void test_seal_write(void)
close(fd);
}
+/*
+ * Test SEAL_FUTURE_WRITE
+ * Test whether SEAL_FUTURE_WRITE actually prevents modifications.
+ */
+static void test_seal_future_write(void)
+{
+ int fd;
+ void *p;
+
+ printf("%s SEAL-FUTURE-WRITE\n", memfd_str);
+
+ fd = mfd_assert_new("kern_memfd_seal_future_write",
+ mfd_def_size,
+ MFD_CLOEXEC | MFD_ALLOW_SEALING);
+
+ p = mfd_assert_mmap_shared(fd);
+
+ mfd_assert_has_seals(fd, 0);
+ /* Not adding grow/shrink seals makes the future write
+ * seal fail to get added
+ */
+ mfd_fail_add_seals(fd, F_SEAL_FUTURE_WRITE);
+
+ mfd_assert_add_seals(fd, F_SEAL_GROW);
+ mfd_assert_has_seals(fd, F_SEAL_GROW);
+
+ /* Should still fail since shrink seal has
+ * not yet been added
+ */
+ mfd_fail_add_seals(fd, F_SEAL_FUTURE_WRITE);
+
+ mfd_assert_add_seals(fd, F_SEAL_SHRINK);
+ mfd_assert_has_seals(fd, F_SEAL_GROW |
+ F_SEAL_SHRINK);
+
+ /* Now should succeed, also verifies that the seal
+ * could be added with an existing writable mmap
+ */
+ mfd_assert_add_seals(fd, F_SEAL_FUTURE_WRITE);
+ mfd_assert_has_seals(fd, F_SEAL_SHRINK |
+ F_SEAL_GROW |
+ F_SEAL_FUTURE_WRITE);
+
+ /* read should pass, writes should fail */
+ mfd_assert_read(fd);
+ mfd_fail_write(fd);
+
+ munmap(p, mfd_def_size);
+ close(fd);
+
+ /* Test adding all seals (grow, shrink, future write) at once */
+ fd = mfd_assert_new("kern_memfd_seal_future_write2",
+ mfd_def_size,
+ MFD_CLOEXEC | MFD_ALLOW_SEALING);
+
+ p = mfd_assert_mmap_shared(fd);
+
+ mfd_assert_has_seals(fd, 0);
+ mfd_assert_add_seals(fd, F_SEAL_SHRINK |
+ F_SEAL_GROW |
+ F_SEAL_FUTURE_WRITE);
+ mfd_assert_has_seals(fd, F_SEAL_SHRINK |
+ F_SEAL_GROW |
+ F_SEAL_FUTURE_WRITE);
+
+ /* read should pass, writes should fail */
+ mfd_assert_read(fd);
+ mfd_fail_write(fd);
+
+ munmap(p, mfd_def_size);
+ close(fd);
+}
+
/*
* Test SEAL_SHRINK
* Test whether SEAL_SHRINK actually prevents shrinking
@@ -945,6 +1018,7 @@ int main(int argc, char **argv)
test_basic();
test_seal_write();
+ test_seal_future_write();
test_seal_shrink();
test_seal_grow();
test_seal_resize();
--
2.19.1.331.ge82ca0e54c-goog
next prev parent reply other threads:[~2018-10-18 6:59 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-18 6:59 [PATCH v3 1/2] mm: Add an F_SEAL_FUTURE_WRITE seal to memfd Joel Fernandes (Google)
2018-10-18 6:59 ` Joel Fernandes (Google) [this message]
2018-10-18 7:08 ` [PATCH v3 2/2] selftests/memfd: Add tests for F_SEAL_FS_WRITE seal Joel Fernandes
2018-10-19 17:32 ` [PATCH v3 1/2] mm: Add an F_SEAL_FUTURE_WRITE seal to memfd valdis.kletnieks
2018-10-19 17:57 ` Joel Fernandes
2018-10-19 18:49 ` valdis.kletnieks
2018-10-19 19:32 ` Joel Fernandes
2018-10-22 23:49 ` Joel Fernandes
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=20181018065908.254389-2-joel@joelfernandes.org \
--to=joel@joelfernandes.org \
--cc=akpm@linux-foundation.org \
--cc=bfields@fieldses.org \
--cc=dancol@google.com \
--cc=gregkh@linuxfoundation.org \
--cc=jlayton@kernel.org \
--cc=john.stultz@linaro.org \
--cc=jreck@google.com \
--cc=kernel-team@android.com \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-kselftest@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=marcandre.lureau@redhat.com \
--cc=mike.kravetz@oracle.com \
--cc=minchan@kernel.org \
--cc=shuah@kernel.org \
--cc=tglx@linutronix.de \
--cc=tkjos@google.com \
--cc=viro@zeniv.linux.org.uk \
/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 NNTP newsgroup(s).