From: Edward Liaw <edliaw@xxxxxxxxxx> commit 3673167a3a07f25b3f06754d69f406edea65543a upstream. This reverts commit e61ef21e27e8deed8c474e9f47f4aa7bc37e138c. uffd_poll_thread may be called by other tests that do not initialize the pthread_barrier, so this approach is not correct. This will revert to using atomic_bool instead. Link: https://lkml.kernel.org/r/20241018171734.2315053-3-edliaw@xxxxxxxxxx Fixes: e61ef21e27e8 ("selftests/mm: replace atomic_bool with pthread_barrier_t") Signed-off-by: Edward Liaw <edliaw@xxxxxxxxxx> Cc: Ryan Roberts <ryan.roberts@xxxxxxx> Cc: Peter Xu <peterx@xxxxxxxxxx> Cc: Shuah Khan <shuah@xxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- tools/testing/selftests/mm/uffd-common.c | 5 ++--- tools/testing/selftests/mm/uffd-common.h | 3 ++- tools/testing/selftests/mm/uffd-unit-tests.c | 14 ++++++-------- 3 files changed, 10 insertions(+), 12 deletions(-) --- a/tools/testing/selftests/mm/uffd-common.c +++ b/tools/testing/selftests/mm/uffd-common.c @@ -17,7 +17,7 @@ bool map_shared; bool test_uffdio_wp = true; unsigned long long *count_verify; uffd_test_ops_t *uffd_test_ops; -pthread_barrier_t ready_for_fork; +atomic_bool ready_for_fork; static int uffd_mem_fd_create(off_t mem_size, bool hugetlb) { @@ -508,8 +508,7 @@ void *uffd_poll_thread(void *arg) pollfd[1].fd = pipefd[cpu*2]; pollfd[1].events = POLLIN; - /* Ready for parent thread to fork */ - pthread_barrier_wait(&ready_for_fork); + ready_for_fork = true; for (;;) { ret = poll(pollfd, 2, -1); --- a/tools/testing/selftests/mm/uffd-common.h +++ b/tools/testing/selftests/mm/uffd-common.h @@ -33,6 +33,7 @@ #include <inttypes.h> #include <stdint.h> #include <sys/random.h> +#include <stdatomic.h> #include "../kselftest.h" #include "vm_util.h" @@ -98,7 +99,7 @@ extern bool map_shared; extern bool test_uffdio_wp; extern unsigned long long *count_verify; extern volatile bool test_uffdio_copy_eexist; -extern pthread_barrier_t ready_for_fork; +extern atomic_bool ready_for_fork; extern uffd_test_ops_t anon_uffd_test_ops; extern uffd_test_ops_t shmem_uffd_test_ops; --- a/tools/testing/selftests/mm/uffd-unit-tests.c +++ b/tools/testing/selftests/mm/uffd-unit-tests.c @@ -770,7 +770,7 @@ static void uffd_sigbus_test_common(bool char c; struct uffd_args args = { 0 }; - pthread_barrier_init(&ready_for_fork, NULL, 2); + ready_for_fork = false; fcntl(uffd, F_SETFL, uffd_flags | O_NONBLOCK); @@ -787,9 +787,8 @@ static void uffd_sigbus_test_common(bool if (pthread_create(&uffd_mon, NULL, uffd_poll_thread, &args)) err("uffd_poll_thread create"); - /* Wait for child thread to start before forking */ - pthread_barrier_wait(&ready_for_fork); - pthread_barrier_destroy(&ready_for_fork); + while (!ready_for_fork) + ; /* Wait for the poll_thread to start executing before forking */ pid = fork(); if (pid < 0) @@ -830,7 +829,7 @@ static void uffd_events_test_common(bool char c; struct uffd_args args = { 0 }; - pthread_barrier_init(&ready_for_fork, NULL, 2); + ready_for_fork = false; fcntl(uffd, F_SETFL, uffd_flags | O_NONBLOCK); if (uffd_register(uffd, area_dst, nr_pages * page_size, @@ -841,9 +840,8 @@ static void uffd_events_test_common(bool if (pthread_create(&uffd_mon, NULL, uffd_poll_thread, &args)) err("uffd_poll_thread create"); - /* Wait for child thread to start before forking */ - pthread_barrier_wait(&ready_for_fork); - pthread_barrier_destroy(&ready_for_fork); + while (!ready_for_fork) + ; /* Wait for the poll_thread to start executing before forking */ pid = fork(); if (pid < 0) Patches currently in stable-queue which might be from edliaw@xxxxxxxxxx are queue-6.6/revert-selftests-mm-fix-deadlock-for-fork-after-pthread_create-on-arm.patch queue-6.6/revert-selftests-mm-replace-atomic_bool-with-pthread_barrier_t.patch
