On Thu, Jun 29, 2023 at 01:50:38PM -0700, Axel Rasmussen wrote:
> Previously, we had "one fault handler to rule them all", which used
> several branches to deal with all of the scenarios required by all of
> the various tests.
>
> In upcoming patches, I plan to add a new test, which has its own
> slightly different fault handling logic. Instead of continuing to add
> cruft to the existing fault handler, let's allow tests to define custom
> ones, separate from other tests.
>
> Signed-off-by: Axel Rasmussen <axelrasmussen@xxxxxxxxxx>
> ---
> tools/testing/selftests/mm/uffd-common.c | 5 ++++-
> tools/testing/selftests/mm/uffd-common.h | 3 +++
> tools/testing/selftests/mm/uffd-stress.c | 12 +++++++-----
> 3 files changed, 14 insertions(+), 6 deletions(-)
>
> diff --git a/tools/testing/selftests/mm/uffd-common.c b/tools/testing/selftests/mm/uffd-common.c
> index ba20d7504022..02b89860e193 100644
> --- a/tools/testing/selftests/mm/uffd-common.c
> +++ b/tools/testing/selftests/mm/uffd-common.c
> @@ -499,6 +499,9 @@ void *uffd_poll_thread(void *arg)
> int ret;
> char tmp_chr;
>
> + if (!args->handle_fault)
> + args->handle_fault = uffd_handle_page_fault;
> +
> pollfd[0].fd = uffd;
> pollfd[0].events = POLLIN;
> pollfd[1].fd = pipefd[cpu*2];
> @@ -527,7 +530,7 @@ void *uffd_poll_thread(void *arg)
> err("unexpected msg event %u\n", msg.event);
> break;
> case UFFD_EVENT_PAGEFAULT:
> - uffd_handle_page_fault(&msg, args);
> + args->handle_fault(&msg, args);
> break;
> case UFFD_EVENT_FORK:
> close(uffd);
> diff --git a/tools/testing/selftests/mm/uffd-common.h b/tools/testing/selftests/mm/uffd-common.h
> index 197f5262fe0d..7c4fa964c3b0 100644
> --- a/tools/testing/selftests/mm/uffd-common.h
> +++ b/tools/testing/selftests/mm/uffd-common.h
> @@ -77,6 +77,9 @@ struct uffd_args {
> unsigned long missing_faults;
> unsigned long wp_faults;
> unsigned long minor_faults;
> +
> + /* A custom fault handler; defaults to uffd_handle_page_fault. */
> + void (*handle_fault)(struct uffd_msg *msg, struct uffd_args *args);
> };
>
> struct uffd_test_ops {
> diff --git a/tools/testing/selftests/mm/uffd-stress.c b/tools/testing/selftests/mm/uffd-stress.c
> index 995ff13e74c7..50b1224d72c7 100644
> --- a/tools/testing/selftests/mm/uffd-stress.c
> +++ b/tools/testing/selftests/mm/uffd-stress.c
> @@ -189,10 +189,8 @@ static int stress(struct uffd_args *args)
> locking_thread, (void *)cpu))
> return 1;
> if (bounces & BOUNCE_POLL) {
> - if (pthread_create(&uffd_threads[cpu], &attr,
> - uffd_poll_thread,
> - (void *)&args[cpu]))
> - return 1;
> + if (pthread_create(&uffd_threads[cpu], &attr, uffd_poll_thread, &args[cpu]))
> + err("uffd_poll_thread create");
irrelevant change?
> } else {
> if (pthread_create(&uffd_threads[cpu], &attr,
> uffd_read_thread,
> @@ -247,9 +245,13 @@ static int userfaultfd_stress(void)
> {
> void *area;
> unsigned long nr;
> - struct uffd_args args[nr_cpus];
> + struct uffd_args *args;
> uint64_t mem_size = nr_pages * page_size;
>
> + args = calloc(nr_cpus, sizeof(struct uffd_args));
> + if (!args)
> + err("allocating args array failed");
> +
It's leaked?
Isn't "args[] = { 0 }" already working?
Thanks,
> if (uffd_test_ctx_init(UFFD_FEATURE_WP_UNPOPULATED, NULL))
> err("context init failed");
>
> --
> 2.41.0.255.g8b1d071c50-goog
>
--
Peter Xu
