Re: [PATCH v2 1/7] kunit: Handle thread creation error
On Fri, Mar 1, 2024 at 2:40 PM Mickaël Salaün wrote:
>
> Previously, if a thread creation failed (e.g. -ENOMEM), the function was
> called (kunit_catch_run_case or kunit_catch_run_case_cleanup) without
> marking the test as failed. Instead, fill try_result with the error
> code returned by kthread_run(), which will mark the test as failed and
> print "internal error occurred...".
Hello!
I have tested this and this fix looks good to me. Thanks!
-Rae
Reviewed-by: Rae Moar
>
> Cc: Brendan Higgins
> Cc: David Gow
> Cc: Rae Moar
> Cc: Shuah Khan
> Reviewed-by: Kees Cook
> Signed-off-by: Mickaël Salaün
> Link: https://lore.kernel.org/r/20240301194037.532117-2-...@digikod.net
> ---
>
> Changes since v1:
> * Added Kees's Reviewed-by.
> ---
> lib/kunit/try-catch.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/lib/kunit/try-catch.c b/lib/kunit/try-catch.c
> index f7825991d576..a5cb2ef70a25 100644
> --- a/lib/kunit/try-catch.c
> +++ b/lib/kunit/try-catch.c
> @@ -69,6 +69,7 @@ void kunit_try_catch_run(struct kunit_try_catch *try_catch,
> void *context)
> 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;
> }
> --
> 2.44.0
>
Re: [PATCH v2 2/7] kunit: Fix kthread reference
On Fri, Mar 1, 2024 at 2:40 PM Mickaël Salaün wrote:
>
> There is a race condition when a kthread finishes after the deadline and
> before the call to kthread_stop(), which may lead to use after free.
Hello!
I have tested this patch and it looks good to me.
Thanks!
-Rae
Reviewed-by: Rae Moar
>
> Cc: Brendan Higgins
> Cc: David Gow
> Cc: Rae Moar
> Cc: Shuah Khan
> Reviewed-by: Kees Cook
> Signed-off-by: Mickaël Salaün
> Link: https://lore.kernel.org/r/20240301194037.532117-3-...@digikod.net
> ---
>
> Changes since v1:
> * Added Kees's Reviewed-by.
> ---
> lib/kunit/try-catch.c | 9 ++---
> 1 file changed, 6 insertions(+), 3 deletions(-)
>
> diff --git a/lib/kunit/try-catch.c b/lib/kunit/try-catch.c
> index a5cb2ef70a25..73f5007f20ea 100644
> --- a/lib/kunit/try-catch.c
> +++ b/lib/kunit/try-catch.c
> @@ -11,6 +11,7 @@
> #include
> #include
> #include
> +#include
>
> #include "try-catch-impl.h"
>
> @@ -65,14 +66,15 @@ void kunit_try_catch_run(struct kunit_try_catch
> *try_catch, void *context)
> try_catch->context = context;
> try_catch->try_completion = &try_completion;
> try_catch->try_result = 0;
> - task_struct = kthread_run(kunit_generic_run_threadfn_adapter,
> - try_catch,
> - "kunit_try_catch_thread");
> + 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);
> + wake_up_process(task_struct);
>
> time_remaining = wait_for_completion_timeout(&try_completion,
> kunit_test_timeout());
> @@ -82,6 +84,7 @@ void kunit_try_catch_run(struct kunit_try_catch *try_catch,
> void *context)
> kthread_stop(task_struct);
> }
>
> + put_task_struct(task_struct);
> exit_code = try_catch->try_result;
>
> if (!exit_code)
> --
> 2.44.0
>
Re: [PATCH v2 3/7] kunit: Fix timeout message
On Fri, Mar 1, 2024 at 2:40 PM Mickaël Salaün wrote:
>
> The exit code is always checked, so let's properly handle the -ETIMEDOUT
> error code.
Hello!
This change looks good to me. Thanks!
-Rae
Reviewed-by: Rae Moar
>
> Cc: Brendan Higgins
> Cc: David Gow
> Cc: Rae Moar
> Cc: Shuah Khan
> Reviewed-by: Kees Cook
> Signed-off-by: Mickaël Salaün
> Link: https://lore.kernel.org/r/20240301194037.532117-4-...@digikod.net
> ---
>
> Changes since v1:
> * Added Kees's Reviewed-by.
> ---
> lib/kunit/try-catch.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/lib/kunit/try-catch.c b/lib/kunit/try-catch.c
> index 73f5007f20ea..cab8b24b5d5a 100644
> --- a/lib/kunit/try-catch.c
> +++ b/lib/kunit/try-catch.c
> @@ -79,7 +79,6 @@ void kunit_try_catch_run(struct kunit_try_catch *try_catch,
> void *context)
> time_remaining = wait_for_completion_timeout(&try_completion,
> kunit_test_timeout());
> if (time_remaining == 0) {
> - kunit_err(test, "try timed out\n");
> try_catch->try_result = -ETIMEDOUT;
> kthread_stop(task_struct);
> }
> @@ -94,6 +93,8 @@ void kunit_try_catch_run(struct kunit_try_catch *try_catch,
> void *context)
> try_catch->try_result = 0;
> else if (exit_code == -EINTR)
> kunit_err(test, "wake_up_process() was never called\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);
>
> --
> 2.44.0
>
Re: [PATCH v2 4/7] kunit: Handle test faults
On Fri, Mar 1, 2024 at 2:40 PM Mickaël Salaün wrote:
>
> Previously, when a kernel test thread crashed (e.g. NULL pointer
> dereference, general protection fault), the KUnit test hanged for 30
> seconds and exited with a timeout error.
>
> Fix this issue by waiting on task_struct->vfork_done instead of the
> custom kunit_try_catch.try_completion, and track the execution state by
> initially setting try_result with -EFAULT and only setting it to 0 if
Hello!
Thanks for your patch! This has been tested and seems pretty good to
me but I just have a few questions. First, do you mean here "setting
try_result with -EINTR" instead?
But happy to add the tested-by.
Tested-by: Rae Moar
Thanks!
-Rae
> the test passed.
>
> Fix kunit_generic_run_threadfn_adapter() signature by returning 0
> instead of calling kthread_complete_and_exit(). Because thread's exit
> code is never checked, always set it to 0 to make it clear.
>
> Fix the -EINTR error message, which couldn't be reached until now.
>
> This is tested with a following patch.
>
> Cc: Brendan Higgins
> Cc: David Gow
> Cc: Rae Moar
> Cc: Shuah Khan
> Reviewed-by: Kees Cook
> Signed-off-by: Mickaël Salaün
> Link: https://lore.kernel.org/r/20240301194037.532117-5-...@digikod.net
> ---
>
> Changes since v1:
> * Added Kees's Reviewed-by.
> ---
> include/kunit/try-catch.h | 3 ---
> lib/kunit/try-catch.c | 14 +++---
> 2 files changed, 7 insertions(+), 10 deletions(-)
>
> diff --git a/include/kunit/try-catch.h b/include/kunit/try-catch.h
> index c507dd43119d..7c966a1adbd3 100644
> --- a/include/kunit/try-catch.h
> +++ b/include/kunit/try-catch.h
> @@ -14,13 +14,11 @@
>
> typedef void (*kunit_try_catch_func_t)(void *);
>
> -struct completion;
> struct kunit;
>
> /**
> * struct kunit_try_catch - provides a generic way to run code which might
> fail.
> * @test: The test case that is currently being executed.
> - * @try_completion: Completion that the control thread waits on while test
> runs.
> * @try_result: Contains any errno obtained while running test case.
> * @try: The function, the test case, to attempt to run.
> * @catch: The function called if @try bails out.
> @@ -46,7 +44,6 @@ struct kunit;
> struct kunit_try_catch {
> /* private: internal use only. */
> struct kunit *test;
> - struct completion *try_completion;
> int try_result;
> kunit_try_catch_func_t try;
> kunit_try_catch_func_t catch;
> diff --git a/lib/kunit/try-catch.c b/lib/kunit/try-catch.c
> index cab8b24b5d5a..c6ee4db0b3bd 100644
> --- a/lib/kunit/try-catch.c
> +++ b/lib/kunit/try-catch.c
> @@ -18,7 +18,7 @@
> void __noreturn kunit_try_catch_throw(struct kunit_try_catch *try_catch)
> {
> try_catch->try_result = -EFAULT;
> - kthread_complete_and_exit(try_catch->try_completion, -EFAULT);
> + kthread_exit(0);
> }
> EXPORT_SYMBOL_GPL(kunit_try_catch_throw);
>
> @@ -26,9 +26,12 @@ 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;
>
> - kthread_complete_and_exit(try_catch->try_completion, 0);
> + return 0;
Really my only question is why we do not need to still do a
kthread_exit(0) here? I realize we are not checking the thread's exit
code but isn't it safer to call kthread_exit(). I'm new to kthread so
I am not too sure.
> }
>
> static unsigned long kunit_test_timeout(void)
> @@ -58,13 +61,11 @@ static unsigned long kunit_test_timeout(void)
>
> void kunit_try_catch_run(struct kunit_try_catch *try_catch, void *context)
> {
> - DECLARE_COMPLETION_ONSTACK(try_completion);
> struct kunit *test = try_catch->test;
> struct task_struct *task_struct;
> int exit_code, time_remaining;
>
> try_catch->context = context;
> - try_catch->try_completion = &try_completion;
> try_catch->try_result = 0;
> task_struct = kthread_create(kunit_generic_run_threadfn_adapter,
> try_catch, "kunit_try_catch_thread");
> @@ -75,8 +76,7 @@ void kunit_try_catch_run(struct kunit_try_catch *try_catch,
> void *context)
> }
> get_task_struct(task_struct);
> wake_up_process(task_struct);
> -
> - time_remaining = wait_for_completion_timeout(&try_completion,
> + time_remaining = wait_for_completion_timeout(task_struc
