I had posted a patch to fix a theoretical race with sysfs and device
removal [0]. While the issue is no longer present with the patch
present, the zram driver has already a lot of enhancements, so much so,
that the race alone is very difficult to reproduce. Likewise, the zram
driver had a series of other races on module removal which I recently
posted fixes for [1], and it makes it unclear if these paper over the
possible theoretical sysfs race. Although we even have gdb output
from an actual race where this issue presented itself, there are
other races which could happen before that and so what we realy need
is a clean separate driver where we can experiment and try to reproduce
unusual races.
This adds such a driver, a new sysfs_test driver, along with a set of
new tests for it. We take hint of observed issues with the sysfs on the
zram driver, and build sandbox based where wher can try to poke holes at
the kernel with.
There are two main races we're after trying to reproduce:
1) proving the deadlock is real
2) allowing for enough slack for us to try to see if we can
reproduce the syfs / device removal race
In order to tackle the second race, we need a bit of help from kernefs,
given that the race is difficult to reproduce. So we add fault injection
support to kernfs, which allows us to trigger all possible races on
write.
This should be enough evidence for us to drop the suggested patch for
sysfs for the second race. The first race however which leads to a
deadlock is clearly explained now and I hope this shows how we need a
generic solution.
[0] https://lkml.kernel.org/r/20210623215007.862787-1-mcgrof@kernel.org
[1] https://lkml.kernel.org/r/20210702043716.2692247-1-mcgrof@kernel.org
Luis Chamberlain (4):
selftests: add tests_sysfs module
kernfs: add initial failure injection support
test_sysfs: add support to use kernfs failure injection
test_sysfs: demonstrate deadlock fix
.../fault-injection/fault-injection.rst | 22 +
MAINTAINERS | 9 +-
fs/kernfs/Makefile | 1 +
fs/kernfs/failure-injection.c | 82 +
fs/kernfs/file.c | 13 +
fs/kernfs/kernfs-internal.h | 73 +
include/linux/kernfs.h | 5 +
lib/Kconfig.debug | 23 +
lib/Makefile | 1 +
lib/test_sysfs.c | 1037 +++++++++++++
tools/testing/selftests/sysfs/Makefile | 12 +
tools/testing/selftests/sysfs/config | 5 +
tools/testing/selftests/sysfs/sysfs.sh | 1376 +++++++++++++++++
13 files changed, 2658 insertions(+), 1 deletion(-)
create mode 100644 fs/kernfs/failure-injection.c
create mode 100644 lib/test_sysfs.c
create mode 100644 tools/testing/selftests/sysfs/Makefile
create mode 100644 tools/testing/selftests/sysfs/config
create mode 100755 tools/testing/selftests/sysfs/sysfs.sh
--
2.27.0
Hi Linus,
Please pull the following Kselftest update for Linux 5.14-rc1.
This Kselftest update for Linux 5.14-rc1 consists of fixes to
existing tests and framework:
-- migrate sgx test to kselftest harness
-- add new test cases to sgx test
-- ftrace test fix event-no-pid on 1-core machine
-- splice test adjust for handler fallback removal
diff is attached.
Apologies if this message appears to have double spacing. My email
client is at fault - I am trying to figure out what changed.
thanks,
-- Shuah
----------------------------------------------------------------
The following changes since commit d07f6ca923ea0927a1024dfccafc5b53b61cfecc:
Linux 5.13-rc2 (2021-05-16 15:27:44 -0700)
are available in the Git repository at:
git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest
tags/linux-kselftest-next-5.14-rc1
for you to fetch changes up to 4896df9d53ae5521f3ce83751e828ad70bc65c80:
selftests/sgx: remove checks for file execute permissions (2021-06-23
18:38:04 -0600)
----------------------------------------------------------------
linux-kselftest-next-5.14-rc1
This Kselftest update for Linux 5.14-rc1 consists of fixes to
existing tests and framework:
-- migrate sgx test to kselftest harness
-- add new test cases to sgx test
-- ftrace test fix event-no-pid on 1-core machine
-- splice test adjust for handler fallback removal
----------------------------------------------------------------
Dave Hansen (1):
selftests/sgx: remove checks for file execute permissions
Jarkko Sakkinen (5):
selftests/sgx: Rename 'eenter' and 'sgx_call_vdso'
selftests/sgx: Migrate to kselftest harness
selftests/sgx: Dump enclave memory map
selftests/sgx: Add EXPECT_EEXIT() macro
selftests/sgx: Refine the test enclave to have storage
Kees Cook (3):
selftests/tls: Add {} to avoid static checker warning
selftests: splice: Adjust for handler fallback removal
selftests: lib.mk: Also install "config" and "settings"
Krzysztof Kozlowski (1):
selftests/ftrace: fix event-no-pid on 1-core machine
Po-Hsu Lin (1):
selftests: timers: rtcpie: skip test if default RTC device does
not exist
Xiaochen Shen (1):
selftests/resctrl: Fix incorrect parsing of option "-t"
.../selftests/ftrace/test.d/event/event-no-pid.tc | 7 +
tools/testing/selftests/lib.mk | 1 +
tools/testing/selftests/net/tls.c | 3 +-
tools/testing/selftests/resctrl/README | 2 +-
tools/testing/selftests/resctrl/resctrl_tests.c | 4 +-
tools/testing/selftests/sgx/call.S | 6 +-
tools/testing/selftests/sgx/defines.h | 10 +
tools/testing/selftests/sgx/load.c | 19 +-
tools/testing/selftests/sgx/main.c | 239
+++++++++++++--------
tools/testing/selftests/sgx/main.h | 4 +-
tools/testing/selftests/sgx/test_encl.c | 19 +-
tools/testing/selftests/sgx/test_encl.lds | 3 +-
.../testing/selftests/splice/short_splice_read.sh | 119 ++++++++--
tools/testing/selftests/timers/rtcpie.c | 10 +-
14 files changed, 308 insertions(+), 138 deletions(-)
----------------------------------------------------------------
Unless the user sets overcommit_memory or has plenty of swap, the latest
changes to the testcase will result in ENOMEM failures for hosts with
less than 64GB RAM. As we do not use much of the allocated memory, we
can use MAP_NORESERVE to avoid this error.
Cc: Zenghui Yu <yuzenghui(a)huawei.com>
Cc: vkuznets(a)redhat.com
Cc: wanghaibin.wang(a)huawei.com
Cc: stable(a)vger.kernel.org
Fixes: 309505dd5685 ("KVM: selftests: Fix mapping length truncation in m{,un}map()")
Signed-off-by: Christian Borntraeger <borntraeger(a)de.ibm.com>
---
tools/testing/selftests/kvm/set_memory_region_test.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/kvm/set_memory_region_test.c b/tools/testing/selftests/kvm/set_memory_region_test.c
index d8812f27648c..d31f54ac4e98 100644
--- a/tools/testing/selftests/kvm/set_memory_region_test.c
+++ b/tools/testing/selftests/kvm/set_memory_region_test.c
@@ -377,7 +377,8 @@ static void test_add_max_memory_regions(void)
(max_mem_slots - 1), MEM_REGION_SIZE >> 10);
mem = mmap(NULL, (size_t)max_mem_slots * MEM_REGION_SIZE + alignment,
- PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+ PROT_READ | PROT_WRITE,
+ MAP_PRIVATE | MAP_ANONYMOUS | MAP_NORESERVE, -1, 0);
TEST_ASSERT(mem != MAP_FAILED, "Failed to mmap() host");
mem_aligned = (void *)(((size_t) mem + alignment - 1) & ~(alignment - 1));
--
2.31.1
This patch addresses misleading error messages reported by kunit_tool in
two cases. First, in the case of TAP output having an incorrect header
format or missing a header, the parser used to output an error message of
'no tests run!'. Now the parser outputs an error message of 'could not
parse test results!'.
As an example:
Before:
$ ./tools/testing/kunit/kunit.py parse /dev/null
[ERROR] no tests run!
...
After:
$ ./tools/testing/kunit/kunit.py parse /dev/null
[ERROR] could not parse test results!
...
Second, in the case of TAP output with the correct header but no
tests, the parser used to output an error message of 'could not parse
test results!'. Now the parser outputs an error message of 'no tests
run!'.
As an example:
Before:
$ echo -e 'TAP version 14\n1..0' | ./tools/testing/kunit/kunit.py parse
[ERROR] could not parse test results!
After:
$ echo -e 'TAP version 14\n1..0' | ./tools/testing/kunit/kunit.py parse
[ERROR] no tests run!
Additionally, this patch also corrects the tests in kunit_tool_test.py
and adds a test to check the error in the case of TAP output with the
correct header but no tests.
Signed-off-by: Rae Moar <rmoar(a)google.com>
Reviewed-by: David Gow <davidgow(a)google.com>
Reviewed-by: Daniel Latypov <dlatypov(a)google.com>
---
V1 -> V2:
* Simplified log for the test for TAP output with the correct header
but no tests
* Added examples in commit message of error messages before and after
---
tools/testing/kunit/kunit_parser.py | 6 ++++--
tools/testing/kunit/kunit_tool_test.py | 16 +++++++++++++---
...st_is_test_passed-no_tests_run_no_header.log} | 0
...t_is_test_passed-no_tests_run_with_header.log | 2 ++
4 files changed, 19 insertions(+), 5 deletions(-)
rename tools/testing/kunit/test_data/{test_is_test_passed-no_tests_run.log => test_is_test_passed-no_tests_run_no_header.log} (100%)
create mode 100644 tools/testing/kunit/test_data/test_is_test_passed-no_tests_run_with_header.log
diff --git a/tools/testing/kunit/kunit_parser.py b/tools/testing/kunit/kunit_parser.py
index c3c524b79db8..b88db3f51dc5 100644
--- a/tools/testing/kunit/kunit_parser.py
+++ b/tools/testing/kunit/kunit_parser.py
@@ -338,9 +338,11 @@ def bubble_up_suite_errors(test_suites: Iterable[TestSuite]) -> TestStatus:
def parse_test_result(lines: LineStream) -> TestResult:
consume_non_diagnostic(lines)
if not lines or not parse_tap_header(lines):
- return TestResult(TestStatus.NO_TESTS, [], lines)
+ return TestResult(TestStatus.FAILURE_TO_PARSE_TESTS, [], lines)
expected_test_suite_num = parse_test_plan(lines)
- if not expected_test_suite_num:
+ if expected_test_suite_num == 0:
+ return TestResult(TestStatus.NO_TESTS, [], lines)
+ elif expected_test_suite_num is None:
return TestResult(TestStatus.FAILURE_TO_PARSE_TESTS, [], lines)
test_suites = []
for i in range(1, expected_test_suite_num + 1):
diff --git a/tools/testing/kunit/kunit_tool_test.py b/tools/testing/kunit/kunit_tool_test.py
index bdae0e5f6197..75045aa0f8a1 100755
--- a/tools/testing/kunit/kunit_tool_test.py
+++ b/tools/testing/kunit/kunit_tool_test.py
@@ -157,8 +157,18 @@ class KUnitParserTest(unittest.TestCase):
kunit_parser.TestStatus.FAILURE,
result.status)
+ def test_no_header(self):
+ empty_log = test_data_path('test_is_test_passed-no_tests_run_no_header.log')
+ with open(empty_log) as file:
+ result = kunit_parser.parse_run_tests(
+ kunit_parser.extract_tap_lines(file.readlines()))
+ self.assertEqual(0, len(result.suites))
+ self.assertEqual(
+ kunit_parser.TestStatus.FAILURE_TO_PARSE_TESTS,
+ result.status)
+
def test_no_tests(self):
- empty_log = test_data_path('test_is_test_passed-no_tests_run.log')
+ empty_log = test_data_path('test_is_test_passed-no_tests_run_with_header.log')
with open(empty_log) as file:
result = kunit_parser.parse_run_tests(
kunit_parser.extract_tap_lines(file.readlines()))
@@ -173,7 +183,7 @@ class KUnitParserTest(unittest.TestCase):
with open(crash_log) as file:
result = kunit_parser.parse_run_tests(
kunit_parser.extract_tap_lines(file.readlines()))
- print_mock.assert_any_call(StrContains('no tests run!'))
+ print_mock.assert_any_call(StrContains('could not parse test results!'))
print_mock.stop()
file.close()
@@ -309,7 +319,7 @@ class KUnitJsonTest(unittest.TestCase):
result["sub_groups"][1]["test_cases"][0])
def test_no_tests_json(self):
- result = self._json_for('test_is_test_passed-no_tests_run.log')
+ result = self._json_for('test_is_test_passed-no_tests_run_with_header.log')
self.assertEqual(0, len(result['sub_groups']))
class StrContains(str):
diff --git a/tools/testing/kunit/test_data/test_is_test_passed-no_tests_run.log b/tools/testing/kunit/test_data/test_is_test_passed-no_tests_run_no_header.log
similarity index 100%
rename from tools/testing/kunit/test_data/test_is_test_passed-no_tests_run.log
rename to tools/testing/kunit/test_data/test_is_test_passed-no_tests_run_no_header.log
diff --git a/tools/testing/kunit/test_data/test_is_test_passed-no_tests_run_with_header.log b/tools/testing/kunit/test_data/test_is_test_passed-no_tests_run_with_header.log
new file mode 100644
index 000000000000..5f48ee659d40
--- /dev/null
+++ b/tools/testing/kunit/test_data/test_is_test_passed-no_tests_run_with_header.log
@@ -0,0 +1,2 @@
+TAP version 14
+1..0
--
2.32.0.93.g670b81a890-goog
Hi,
This is v8 of syscall user dispatch. Last version got some acks but
there was one small documentation fix I wanted to do, as requested by
Florian. This also addresses the commit message fixup Peter requested.
The only actual code change from v7 is solving a trivial merge conflict
I myself created with the entry code fixup I made week and with
something else in the TIP tree.
I also shared this with glibc and there wasn't any complaints other than
the matter about user-notif vs. siginfo, which was discussed in v7 and
the understanding is that it is not necessary now and can be added
later, if needed, on the same infrastructure without a new api.
I'm not sure about TIP the rules, but is it too late to be queued for
the next merge window? I'd love to have this in 5.11 if possible, since
it has been flying for quite a while.
This is based on tip/master.
As usual, a working tree with this patchset is available at:
https://gitlab.collabora.com/krisman/linux -b syscall-user-dispatch-v8
Previous submissions are archived at:
RFC/v1: https://lkml.org/lkml/2020/7/8/96
v2: https://lkml.org/lkml/2020/7/9/17
v3: https://lkml.org/lkml/2020/7/12/4
v4: https://www.spinics.net/lists/linux-kselftest/msg16377.html
v5: https://lkml.org/lkml/2020/8/10/1320
v6: https://lkml.org/lkml/2020/9/4/1122
v7: https://lwn.net/Articles/837598/
Gabriel Krisman Bertazi (7):
x86: vdso: Expose sigreturn address on vdso to the kernel
signal: Expose SYS_USER_DISPATCH si_code type
kernel: Implement selective syscall userspace redirection
entry: Support Syscall User Dispatch on common syscall entry
selftests: Add kselftest for syscall user dispatch
selftests: Add benchmark for syscall user dispatch
docs: Document Syscall User Dispatch
.../admin-guide/syscall-user-dispatch.rst | 87 +++++
arch/x86/entry/vdso/vdso2c.c | 2 +
arch/x86/entry/vdso/vdso32/sigreturn.S | 2 +
arch/x86/entry/vdso/vma.c | 15 +
arch/x86/include/asm/elf.h | 2 +
arch/x86/include/asm/vdso.h | 2 +
arch/x86/kernel/signal_compat.c | 2 +-
fs/exec.c | 3 +
include/linux/entry-common.h | 2 +
include/linux/sched.h | 2 +
include/linux/syscall_user_dispatch.h | 40 +++
include/linux/thread_info.h | 2 +
include/uapi/asm-generic/siginfo.h | 3 +-
include/uapi/linux/prctl.h | 5 +
kernel/entry/Makefile | 2 +-
kernel/entry/common.c | 17 +
kernel/entry/common.h | 16 +
kernel/entry/syscall_user_dispatch.c | 102 ++++++
kernel/fork.c | 1 +
kernel/sys.c | 5 +
tools/testing/selftests/Makefile | 1 +
.../syscall_user_dispatch/.gitignore | 3 +
.../selftests/syscall_user_dispatch/Makefile | 9 +
.../selftests/syscall_user_dispatch/config | 1 +
.../syscall_user_dispatch/sud_benchmark.c | 200 +++++++++++
.../syscall_user_dispatch/sud_test.c | 310 ++++++++++++++++++
26 files changed, 833 insertions(+), 3 deletions(-)
create mode 100644 Documentation/admin-guide/syscall-user-dispatch.rst
create mode 100644 include/linux/syscall_user_dispatch.h
create mode 100644 kernel/entry/common.h
create mode 100644 kernel/entry/syscall_user_dispatch.c
create mode 100644 tools/testing/selftests/syscall_user_dispatch/.gitignore
create mode 100644 tools/testing/selftests/syscall_user_dispatch/Makefile
create mode 100644 tools/testing/selftests/syscall_user_dispatch/config
create mode 100644 tools/testing/selftests/syscall_user_dispatch/sud_benchmark.c
create mode 100644 tools/testing/selftests/syscall_user_dispatch/sud_test.c
--
2.29.2
This patch addresses misleading error messages reported by kunit_tool in
two cases. First, in the case of TAP output having an incorrect header
format or missing a header, the parser used to output an error message of
'no tests run!'. Now the parser outputs an error message of 'could not
parse test results!'.
As an example:
Before:
$ ./tools/testing/kunit/kunit.py parse /dev/null
[ERROR] no tests run!
...
After:
$ ./tools/testing/kunit/kunit.py parse /dev/null
[ERROR] could not parse test results!
...
Second, in the case of TAP output with the correct header but no
tests, the parser used to output an error message of 'could not parse
test results!'. Now the parser outputs an error message of 'no tests
run!'.
As an example:
Before:
$ echo -e 'TAP version 14\n1..0' | ./tools/testing/kunit/kunit.py parse
[ERROR] could not parse test results!
After:
$ echo -e 'TAP version 14\n1..0' | ./tools/testing/kunit/kunit.py parse
[ERROR] no tests run!
Additionally, this patch also corrects the tests in kunit_tool_test.py
and adds a test to check the error in the case of TAP output with the
correct header but no tests (the log for this test was simplified from
the first version of this patch).
Signed-off-by: Rae Moar <rmoar(a)google.com>
---
tools/testing/kunit/kunit_parser.py | 6 ++++--
tools/testing/kunit/kunit_tool_test.py | 16 +++++++++++++---
...st_is_test_passed-no_tests_run_no_header.log} | 0
...t_is_test_passed-no_tests_run_with_header.log | 2 ++
4 files changed, 19 insertions(+), 5 deletions(-)
rename tools/testing/kunit/test_data/{test_is_test_passed-no_tests_run.log => test_is_test_passed-no_tests_run_no_header.log} (100%)
create mode 100644 tools/testing/kunit/test_data/test_is_test_passed-no_tests_run_with_header.log
diff --git a/tools/testing/kunit/kunit_parser.py b/tools/testing/kunit/kunit_parser.py
index c3c524b79db8..b88db3f51dc5 100644
--- a/tools/testing/kunit/kunit_parser.py
+++ b/tools/testing/kunit/kunit_parser.py
@@ -338,9 +338,11 @@ def bubble_up_suite_errors(test_suites: Iterable[TestSuite]) -> TestStatus:
def parse_test_result(lines: LineStream) -> TestResult:
consume_non_diagnostic(lines)
if not lines or not parse_tap_header(lines):
- return TestResult(TestStatus.NO_TESTS, [], lines)
+ return TestResult(TestStatus.FAILURE_TO_PARSE_TESTS, [], lines)
expected_test_suite_num = parse_test_plan(lines)
- if not expected_test_suite_num:
+ if expected_test_suite_num == 0:
+ return TestResult(TestStatus.NO_TESTS, [], lines)
+ elif expected_test_suite_num is None:
return TestResult(TestStatus.FAILURE_TO_PARSE_TESTS, [], lines)
test_suites = []
for i in range(1, expected_test_suite_num + 1):
diff --git a/tools/testing/kunit/kunit_tool_test.py b/tools/testing/kunit/kunit_tool_test.py
index bdae0e5f6197..75045aa0f8a1 100755
--- a/tools/testing/kunit/kunit_tool_test.py
+++ b/tools/testing/kunit/kunit_tool_test.py
@@ -157,8 +157,18 @@ class KUnitParserTest(unittest.TestCase):
kunit_parser.TestStatus.FAILURE,
result.status)
+ def test_no_header(self):
+ empty_log = test_data_path('test_is_test_passed-no_tests_run_no_header.log')
+ with open(empty_log) as file:
+ result = kunit_parser.parse_run_tests(
+ kunit_parser.extract_tap_lines(file.readlines()))
+ self.assertEqual(0, len(result.suites))
+ self.assertEqual(
+ kunit_parser.TestStatus.FAILURE_TO_PARSE_TESTS,
+ result.status)
+
def test_no_tests(self):
- empty_log = test_data_path('test_is_test_passed-no_tests_run.log')
+ empty_log = test_data_path('test_is_test_passed-no_tests_run_with_header.log')
with open(empty_log) as file:
result = kunit_parser.parse_run_tests(
kunit_parser.extract_tap_lines(file.readlines()))
@@ -173,7 +183,7 @@ class KUnitParserTest(unittest.TestCase):
with open(crash_log) as file:
result = kunit_parser.parse_run_tests(
kunit_parser.extract_tap_lines(file.readlines()))
- print_mock.assert_any_call(StrContains('no tests run!'))
+ print_mock.assert_any_call(StrContains('could not parse test results!'))
print_mock.stop()
file.close()
@@ -309,7 +319,7 @@ class KUnitJsonTest(unittest.TestCase):
result["sub_groups"][1]["test_cases"][0])
def test_no_tests_json(self):
- result = self._json_for('test_is_test_passed-no_tests_run.log')
+ result = self._json_for('test_is_test_passed-no_tests_run_with_header.log')
self.assertEqual(0, len(result['sub_groups']))
class StrContains(str):
diff --git a/tools/testing/kunit/test_data/test_is_test_passed-no_tests_run.log b/tools/testing/kunit/test_data/test_is_test_passed-no_tests_run_no_header.log
similarity index 100%
rename from tools/testing/kunit/test_data/test_is_test_passed-no_tests_run.log
rename to tools/testing/kunit/test_data/test_is_test_passed-no_tests_run_no_header.log
diff --git a/tools/testing/kunit/test_data/test_is_test_passed-no_tests_run_with_header.log b/tools/testing/kunit/test_data/test_is_test_passed-no_tests_run_with_header.log
new file mode 100644
index 000000000000..5f48ee659d40
--- /dev/null
+++ b/tools/testing/kunit/test_data/test_is_test_passed-no_tests_run_with_header.log
@@ -0,0 +1,2 @@
+TAP version 14
+1..0
--
2.32.0.93.g670b81a890-goog