linux/lib/kunit/try-catch.c

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// SPDX-License-Identifier: GPL-2.0
/*
* An API to allow a function, that may fail, to be executed, and recover in a
* controlled manner.
*
* Copyright (C) 2019, Google LLC.
* Author: Brendan Higgins <brendanhiggins@google.com>
*/
#include <kunit/test.h>
#include <linux/completion.h>
#include <linux/kernel.h>
#include <linux/kthread.h>
#include <linux/sched/task.h>
#include "try-catch-impl.h"
void __noreturn kunit_try_catch_throw(struct kunit_try_catch *try_catch)
{
try_catch->try_result = -EFAULT;
kthread_exit(0);
}
kunit: allow kunit tests to be loaded as a module As tests are added to kunit, it will become less feasible to execute all built tests together. By supporting modular tests we provide a simple way to do selective execution on a running system; specifying CONFIG_KUNIT=y CONFIG_KUNIT_EXAMPLE_TEST=m ...means we can simply "insmod example-test.ko" to run the tests. To achieve this we need to do the following: o export the required symbols in kunit o string-stream tests utilize non-exported symbols so for now we skip building them when CONFIG_KUNIT_TEST=m. o drivers/base/power/qos-test.c contains a few unexported interface references, namely freq_qos_read_value() and freq_constraints_init(). Both of these could be potentially defined as static inline functions in include/linux/pm_qos.h, but for now we simply avoid supporting module build for that test suite. o support a new way of declaring test suites. Because a module cannot do multiple late_initcall()s, we provide a kunit_test_suites() macro to declare multiple suites within the same module at once. o some test module names would have been too general ("test-test" and "example-test" for kunit tests, "inode-test" for ext4 tests); rename these as appropriate ("kunit-test", "kunit-example-test" and "ext4-inode-test" respectively). Also define kunit_test_suite() via kunit_test_suites() as callers in other trees may need the old definition. Co-developed-by: Knut Omang <knut.omang@oracle.com> Signed-off-by: Knut Omang <knut.omang@oracle.com> Signed-off-by: Alan Maguire <alan.maguire@oracle.com> Reviewed-by: Brendan Higgins <brendanhiggins@google.com> Acked-by: Theodore Ts'o <tytso@mit.edu> # for ext4 bits Acked-by: David Gow <davidgow@google.com> # For list-test Reported-by: kbuild test robot <lkp@intel.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2020-01-06 22:28:20 +00:00
EXPORT_SYMBOL_GPL(kunit_try_catch_throw);
static int kunit_generic_run_threadfn_adapter(void *data)
{
struct kunit_try_catch *try_catch = data;
try_catch->try_result = -EINTR;
try_catch->try(try_catch->context);
if (try_catch->try_result == -EINTR)
try_catch->try_result = 0;
return 0;
}
static unsigned long kunit_test_timeout(void)
{
/*
* TODO(brendanhiggins@google.com): We should probably have some type of
* variable timeout here. The only question is what that timeout value
* should be.
*
* The intention has always been, at some point, to be able to label
* tests with some type of size bucket (unit/small, integration/medium,
* large/system/end-to-end, etc), where each size bucket would get a
* default timeout value kind of like what Bazel does:
* https://docs.bazel.build/versions/master/be/common-definitions.html#test.size
* There is still some debate to be had on exactly how we do this. (For
* one, we probably want to have some sort of test runner level
* timeout.)
*
* For more background on this topic, see:
* https://mike-bland.com/2011/11/01/small-medium-large.html
*
* If tests timeout due to exceeding sysctl_hung_task_timeout_secs,
* the task will be killed and an oops generated.
*/
return 300 * msecs_to_jiffies(MSEC_PER_SEC); /* 5 min */
}
void kunit_try_catch_run(struct kunit_try_catch *try_catch, void *context)
{
struct kunit *test = try_catch->test;
struct task_struct *task_struct;
struct completion *task_done;
int exit_code, time_remaining;
try_catch->context = context;
try_catch->try_result = 0;
task_struct = kthread_create(kunit_generic_run_threadfn_adapter,
try_catch, "kunit_try_catch_thread");
if (IS_ERR(task_struct)) {
try_catch->try_result = PTR_ERR(task_struct);
try_catch->catch(try_catch->context);
return;
}
get_task_struct(task_struct);
/*
* As for a vfork(2), task_struct->vfork_done (pointing to the
* underlying kthread->exited) can be used to wait for the end of a
* kernel thread. It is set to NULL when the thread exits, so we
* keep a copy here.
*/
task_done = task_struct->vfork_done;
wake_up_process(task_struct);
time_remaining = wait_for_completion_timeout(task_done,
kunit_test_timeout());
if (time_remaining == 0) {
try_catch->try_result = -ETIMEDOUT;
kunit: fix UAF when run kfence test case test_gfpzero Patch series "kunit: fix a UAF bug and do some optimization", v2. This series is to fix UAF (use after free) when running kfence test case test_gfpzero, which is time costly. This UAF bug can be easily triggered by setting CONFIG_KFENCE_NUM_OBJECTS = 65535. Furthermore, some optimization for kunit tests has been done. This patch (of 3): Kunit will create a new thread to run an actual test case, and the main process will wait for the completion of the actual test thread until overtime. The variable "struct kunit test" has local property in function kunit_try_catch_run, and will be used in the test case thread. Task kunit_try_catch_run will free "struct kunit test" when kunit runs overtime, but the actual test case is still run and an UAF bug will be triggered. The above problem has been both observed in a physical machine and qemu platform when running kfence kunit tests. The problem can be triggered when setting CONFIG_KFENCE_NUM_OBJECTS = 65535. Under this setting, the test case test_gfpzero will cost hours and kunit will run to overtime. The follows show the panic log. BUG: unable to handle page fault for address: ffffffff82d882e9 Call Trace: kunit_log_append+0x58/0xd0 ... test_alloc.constprop.0.cold+0x6b/0x8a [kfence_test] test_gfpzero.cold+0x61/0x8ab [kfence_test] kunit_try_run_case+0x4c/0x70 kunit_generic_run_threadfn_adapter+0x11/0x20 kthread+0x166/0x190 ret_from_fork+0x22/0x30 Kernel panic - not syncing: Fatal exception Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014 To solve this problem, the test case thread should be stopped when the kunit frame runs overtime. The stop signal will send in function kunit_try_catch_run, and test_gfpzero will handle it. Link: https://lkml.kernel.org/r/20220309083753.1561921-1-liupeng256@huawei.com Link: https://lkml.kernel.org/r/20220309083753.1561921-2-liupeng256@huawei.com Signed-off-by: Peng Liu <liupeng256@huawei.com> Reviewed-by: Marco Elver <elver@google.com> Reviewed-by: Brendan Higgins <brendanhiggins@google.com> Tested-by: Brendan Higgins <brendanhiggins@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Wang Kefeng <wangkefeng.wang@huawei.com> Cc: Daniel Latypov <dlatypov@google.com> Cc: David Gow <davidgow@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-22 21:48:16 +00:00
kthread_stop(task_struct);
}
put_task_struct(task_struct);
exit_code = try_catch->try_result;
if (!exit_code)
return;
if (exit_code == -EFAULT)
try_catch->try_result = 0;
else if (exit_code == -EINTR) {
if (test->last_seen.file)
kunit_err(test, "try faulted: last line seen %s:%d\n",
test->last_seen.file, test->last_seen.line);
else
kunit_err(test, "try faulted\n");
} else if (exit_code == -ETIMEDOUT)
kunit_err(test, "try timed out\n");
else if (exit_code)
kunit_err(test, "Unknown error: %d\n", exit_code);
try_catch->catch(try_catch->context);
}
kunit: allow kunit tests to be loaded as a module As tests are added to kunit, it will become less feasible to execute all built tests together. By supporting modular tests we provide a simple way to do selective execution on a running system; specifying CONFIG_KUNIT=y CONFIG_KUNIT_EXAMPLE_TEST=m ...means we can simply "insmod example-test.ko" to run the tests. To achieve this we need to do the following: o export the required symbols in kunit o string-stream tests utilize non-exported symbols so for now we skip building them when CONFIG_KUNIT_TEST=m. o drivers/base/power/qos-test.c contains a few unexported interface references, namely freq_qos_read_value() and freq_constraints_init(). Both of these could be potentially defined as static inline functions in include/linux/pm_qos.h, but for now we simply avoid supporting module build for that test suite. o support a new way of declaring test suites. Because a module cannot do multiple late_initcall()s, we provide a kunit_test_suites() macro to declare multiple suites within the same module at once. o some test module names would have been too general ("test-test" and "example-test" for kunit tests, "inode-test" for ext4 tests); rename these as appropriate ("kunit-test", "kunit-example-test" and "ext4-inode-test" respectively). Also define kunit_test_suite() via kunit_test_suites() as callers in other trees may need the old definition. Co-developed-by: Knut Omang <knut.omang@oracle.com> Signed-off-by: Knut Omang <knut.omang@oracle.com> Signed-off-by: Alan Maguire <alan.maguire@oracle.com> Reviewed-by: Brendan Higgins <brendanhiggins@google.com> Acked-by: Theodore Ts'o <tytso@mit.edu> # for ext4 bits Acked-by: David Gow <davidgow@google.com> # For list-test Reported-by: kbuild test robot <lkp@intel.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2020-01-06 22:28:20 +00:00
EXPORT_SYMBOL_GPL(kunit_try_catch_run);