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10 commits

Author SHA1 Message Date
Shuah Khan
fc1d330358 selftests/core: remove ARRAY_SIZE define from close_range_test.c
ARRAY_SIZE is defined in several selftests. Remove definitions from
individual test files and include header file for the define instead.
ARRAY_SIZE define is added in a separate patch to prepare for this
change.

Remove ARRAY_SIZE from close_range_test.c and pickup the one defined
in kselftest.h.

Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2021-12-10 17:50:38 -07:00
Shuah Khan
f35dcaa0a8 selftests/core: fix conflicting types compile error for close_range()
close_range() test type conflicts with close_range() library call in
x86_64-linux-gnu/bits/unistd_ext.h. Fix it by changing the name to
core_close_range().

gcc -g -I../../../../usr/include/    close_range_test.c  -o ../tools/testing/selftests/core/close_range_test
In file included from close_range_test.c:16:
close_range_test.c:57:6: error: conflicting types for ‘close_range’; have ‘void(struct __test_metadata *)’
   57 | TEST(close_range)
      |      ^~~~~~~~~~~
../kselftest_harness.h:181:21: note: in definition of macro ‘__TEST_IMPL’
  181 |         static void test_name(struct __test_metadata *_metadata); \
      |                     ^~~~~~~~~
close_range_test.c:57:1: note: in expansion of macro ‘TEST’
   57 | TEST(close_range)
      | ^~~~
In file included from /usr/include/unistd.h:1204,
                 from close_range_test.c:13:
/usr/include/x86_64-linux-gnu/bits/unistd_ext.h:56:12: note: previous declaration of ‘close_range’ with type ‘int(unsigned int,  unsigned int,  int)’
   56 | extern int close_range (unsigned int __fd, unsigned int __max_fd,
      |            ^~~~~~~~~~~

Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2021-10-29 13:09:42 -06:00
Christian Brauner
6abc20f8f8
selftests/core: add regression test for CLOSE_RANGE_UNSHARE | CLOSE_RANGE_CLOEXEC
This test is a minimalized version of the reproducer given by syzbot
(cf. [1]).

After introducing CLOSE_RANGE_CLOEXEC syzbot reported a crash when
CLOSE_RANGE_CLOEXEC is specified in conjunction with
CLOSE_RANGE_UNSHARE. When CLOSE_RANGE_UNSHARE is specified the caller
will receive a private file descriptor table in case their file
descriptor table is currently shared.
For the case where the caller has requested all file descriptors to be
actually closed via e.g. close_range(3, ~0U, 0) the kernel knows that
the caller does not need any of the file descriptors anymore and will
optimize the close operation by only copying all files in the range from
0 to 3 and no others.

However, if the caller requested CLOSE_RANGE_CLOEXEC together with
CLOSE_RANGE_UNSHARE the caller wants to still make use of the file
descriptors so the kernel needs to copy all of them and can't optimize.

The original patch didn't account for this and thus could cause oopses
as evidenced by the syzbot report. Add tests for this regression.

We first create a huge gap in the fd table. When we now call
CLOSE_RANGE_UNSHARE with a shared fd table and and with ~0U as upper
bound the kernel will only copy up to fd1 file descriptors into the new
fd table. If the kernel is buggy and doesn't handle CLOSE_RANGE_CLOEXEC
correctly it will not have copied all file descriptors and we will oops!

This test passes on a fixed kernel and will trigger an oops on a buggy
kernel.

[1]: https://syzkaller.appspot.com/text?tag=KernelConfig&x=db720fe37a6a41d8

Cc: Giuseppe Scrivano <gscrivan@redhat.com>
Cc: linux-fsdevel@vger.kernel.org
Link: syzbot+96cfd2b22b3213646a93@syzkaller.appspotmail.com
Link: https://lore.kernel.org/r/20201218145415.801063-4-christian.brauner@ubuntu.com
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2020-12-19 16:23:19 +01:00
Christian Brauner
fe325c3ff3
selftests/core: add test for CLOSE_RANGE_UNSHARE | CLOSE_RANGE_CLOEXEC
Add a test to verify that CLOSE_RANGE_UNSHARE works correctly when combined
with CLOSE_RANGE_CLOEXEC for the single-threaded case.

Cc: Giuseppe Scrivano <gscrivan@redhat.com>
Cc: linux-fsdevel@vger.kernel.org
Link: https://lore.kernel.org/r/20201218145415.801063-3-christian.brauner@ubuntu.com
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2020-12-19 16:23:18 +01:00
Christian Brauner
ae78ba8d3b
selftests/core: handle missing syscall number for close_range
This improves the syscall number handling in the close_range()
selftests. This should handle any architecture.

Cc: Giuseppe Scrivano <gscrivan@redhat.com>
Cc: linux-fsdevel@vger.kernel.org
Link: https://lore.kernel.org/r/20201218145415.801063-2-christian.brauner@ubuntu.com
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2020-12-19 16:23:18 +01:00
Tobias Klauser
ca202504ea
selftests/core: fix close_range_test build after XFAIL removal
XFAIL was removed in commit 9847d24af9 ("selftests/harness: Refactor
XFAIL into SKIP") and its use in close_range_test was already replaced
by commit 1d44d0dd61 ("selftests: core: use SKIP instead of XFAIL in
close_range_test.c"). However, commit 23afeaeff3 ("selftests: core:
add tests for CLOSE_RANGE_CLOEXEC") introduced usage of XFAIL in
TEST(close_range_cloexec). Use SKIP there as well.

Fixes: 23afeaeff3 ("selftests: core: add tests for CLOSE_RANGE_CLOEXEC")
Cc: Giuseppe Scrivano <gscrivan@redhat.com>
Cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Link: https://lore.kernel.org/r/20201218112428.13662-1-tklauser@distanz.ch
Link: https://lore.kernel.org/r/20201218145415.801063-1-christian.brauner@ubuntu.com
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2020-12-19 16:23:18 +01:00
Giuseppe Scrivano
23afeaeff3
selftests: core: add tests for CLOSE_RANGE_CLOEXEC
check that close_range(initial_fd, last_fd, CLOSE_RANGE_CLOEXEC)
correctly sets the close-on-exec bit for the specified file
descriptors.

Open 100 file descriptors and set the close-on-exec flag for a subset
of them first, then set it for every file descriptor above 2.  Make
sure RLIMIT_NOFILE doesn't affect the result.

Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>
Link: https://lore.kernel.org/r/20201118104746.873084-3-gscrivan@redhat.com
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2020-12-04 12:06:16 +01:00
Tommi Rantala
1d44d0dd61 selftests: core: use SKIP instead of XFAIL in close_range_test.c
XFAIL is gone since commit 9847d24af9 ("selftests/harness: Refactor XFAIL
into SKIP"), use SKIP instead.

Fixes: 9847d24af9 ("selftests/harness: Refactor XFAIL into SKIP")
Signed-off-by: Tommi Rantala <tommi.t.rantala@nokia.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2020-11-05 10:08:15 -07:00
Christian Brauner
a5161eeef9
tests: add CLOSE_RANGE_UNSHARE tests
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2020-06-17 00:07:38 +02:00
Christian Brauner
2c5db60e46
tests: add close_range() tests
This adds basic tests for the new close_range() syscall.
- test that no invalid flags can be passed
- test that a range of file descriptors is correctly closed
- test that a range of file descriptors is correctly closed if there there
  are already closed file descriptors in the range
- test that max_fd is correctly capped to the current fdtable maximum

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Jann Horn <jannh@google.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Dmitry V. Levin <ldv@altlinux.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: linux-api@vger.kernel.org
Cc: linux-kselftest@vger.kernel.org
2020-06-17 00:07:38 +02:00