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[PATCH v2] selftests/mm: Confirm VA exhaustion without reliance on correctness of mmap()

by Dev Jain

Currently, VA exhaustion is being checked by passing a hint to mmap() and expecting it to fail. This patch makes a stricter test by successful write() calls from /proc/self/maps to a dump file, confirming that a free chunk is indeed not available. Changes in v2: - Replace SZ_1GB with MAP_CHUNK_SIZE, tidy-up Signed-off-by: Dev Jain <dev.jain(a)arm.com> --- Merge dependency: https://lore.kernel.org/all/20240314122250.68534-1-dev.jain@arm.com/ .../selftests/mm/virtual_address_range.c | 66 +++++++++++++++++++ 1 file changed, 66 insertions(+) diff --git a/tools/testing/selftests/mm/virtual_address_range.c b/tools/testing/selftests/mm/virtual_address_range.c index 7bcf8d48256a..050e997e3be2 100644 --- a/tools/testing/selftests/mm/virtual_address_range.c +++ b/tools/testing/selftests/mm/virtual_address_range.c @@ -12,6 +12,8 @@ #include <errno.h> #include <sys/mman.h> #include <sys/time.h> +#include <fcntl.h> + #include "../kselftest.h" /* @@ -93,6 +95,66 @@ static int validate_lower_address_hint(void) return 1; } +static int validate_complete_va_space(void) +{ + unsigned long start_addr, end_addr, prev_end_addr; + char line[400]; + char prot[6]; + FILE *file; + int fd; + + fd = open("va_dump", O_CREAT | O_WRONLY, 0600); + unlink("va_dump"); + if (fd < 0) { + ksft_test_result_skip("cannot create or open dump file\n"); + ksft_finished(); + } + + file = fopen("/proc/self/maps", "r"); + if (file == NULL) + ksft_exit_fail_msg("cannot open /proc/self/maps\n"); + + prev_end_addr = 0; + while (fgets(line, sizeof(line), file)) { + unsigned long hop; + + if (sscanf(line, "%lx-%lx %s[rwxp-]", + &start_addr, &end_addr, prot) != 3) + ksft_exit_fail_msg("cannot parse /proc/self/maps\n"); + + /* end of userspace mappings; ignore vsyscall mapping */ + if (start_addr & (1UL << 63)) + return 0; + + /* /proc/self/maps must have gaps less than MAP_CHUNK_SIZE */ + if (start_addr - prev_end_addr >= MAP_CHUNK_SIZE) + return 1; + + prev_end_addr = end_addr; + + if (prot[0] != 'r') + continue; + + /* + * Confirm whether MAP_CHUNK_SIZE chunk can be found or not. + * If write succeeds, no need to check MAP_CHUNK_SIZE - 1 + * addresses after that. If the address was not held by this + * process, write would fail with errno set to EFAULT. + * Anyways, if write returns anything apart from 1, exit the + * program since that would mean a bug in /proc/self/maps. + */ + hop = 0; + while (start_addr + hop < end_addr) { + if (write(fd, (void *)(start_addr + hop), 1) != 1) + return 1; + lseek(fd, 0, SEEK_SET); + + hop += MAP_CHUNK_SIZE; + } + } + return 0; +} + int main(int argc, char *argv[]) { char *ptr[NR_CHUNKS_LOW]; @@ -135,6 +197,10 @@ int main(int argc, char *argv[]) validate_addr(hptr[i], 1); } hchunks = i; + if (validate_complete_va_space()) { + ksft_test_result_fail("BUG in mmap() or /proc/self/maps\n"); + ksft_finished(); + } for (i = 0; i < lchunks; i++) munmap(ptr[i], MAP_CHUNK_SIZE); -- 2.34.1

10 months

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[PATCH bpf] selftests/bpf: verifier_arena: fix mmap address for arm64

by Puranjay Mohan

The arena_list selftest uses (1ull << 32) in the mmap address computation for arm64. Use the same in the verifier_arena selftest. This makes the selftest pass for arm64 on the CI[1]. [1] https://github.com/kernel-patches/bpf/pull/6622 Signed-off-by: Puranjay Mohan <puranjay12(a)gmail.com> --- tools/testing/selftests/bpf/progs/verifier_arena.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/bpf/progs/verifier_arena.c b/tools/testing/selftests/bpf/progs/verifier_arena.c index 5540b05ff9ee..91818a84e86d 100644 --- a/tools/testing/selftests/bpf/progs/verifier_arena.c +++ b/tools/testing/selftests/bpf/progs/verifier_arena.c @@ -12,7 +12,11 @@ struct { __uint(type, BPF_MAP_TYPE_ARENA); __uint(map_flags, BPF_F_MMAPABLE); __uint(max_entries, 2); /* arena of two pages close to 32-bit boundary*/ - __ulong(map_extra, (1ull << 44) | (~0u - __PAGE_SIZE * 2 + 1)); /* start of mmap() region */ +#ifdef __TARGET_ARCH_arm64 + __ulong(map_extra, (1ull << 32) | (~0u - __PAGE_SIZE * 2 + 1)); /* start of mmap() region */ +#else + __ulong(map_extra, (1ull << 44) | (~0u - __PAGE_SIZE * 2 + 1)); /* start of mmap() region */ +#endif } arena SEC(".maps"); SEC("syscall") -- 2.40.1

10 months

2
1
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[PATCH] selftests/mm: Confirm VA exhaustion without reliance on correctness of mmap()

by Dev Jain

Currently, VA exhaustion is being checked by passing a hint to mmap() and expecting it to fail. This patch makes a stricter test by successful write() calls from /proc/self/maps to a dump file, confirming that a free chunk is indeed not available. Signed-off-by: Dev Jain <dev.jain(a)arm.com> --- Merge dependency: https://lore.kernel.org/all/20240314122250.68534-1-dev.jain@arm.com/ .../selftests/mm/virtual_address_range.c | 69 +++++++++++++++++++ 1 file changed, 69 insertions(+) diff --git a/tools/testing/selftests/mm/virtual_address_range.c b/tools/testing/selftests/mm/virtual_address_range.c index 7bcf8d48256a..31063613dfd9 100644 --- a/tools/testing/selftests/mm/virtual_address_range.c +++ b/tools/testing/selftests/mm/virtual_address_range.c @@ -12,6 +12,8 @@ #include <errno.h> #include <sys/mman.h> #include <sys/time.h> +#include <fcntl.h> + #include "../kselftest.h" /* @@ -93,6 +95,69 @@ static int validate_lower_address_hint(void) return 1; } +static int validate_complete_va_space(void) +{ + unsigned long start_addr, end_addr, prev_end_addr; + char line[400]; + char prot[6]; + FILE *file; + int fd; + + fd = open("va_dump", O_CREAT | O_WRONLY, 0600); + unlink("va_dump"); + if (fd < 0) { + ksft_test_result_skip("cannot create or open dump file\n"); + ksft_finished(); + } + + file = fopen("/proc/self/maps", "r"); + if (file == NULL) + ksft_exit_fail_msg("cannot open /proc/self/maps\n"); + + prev_end_addr = 0; + while (fgets(line, sizeof(line), file)) { + unsigned long hop; + int ret; + + ret = sscanf(line, "%lx-%lx %s[rwxp-]", + &start_addr, &end_addr, prot); + if (ret != 3) + ksft_exit_fail_msg("sscanf failed, cannot parse\n"); + + /* end of userspace mappings; ignore vsyscall mapping */ + if (start_addr & (1UL << 63)) + return 0; + + /* /proc/self/maps must have gaps less than 1GB only */ + if (start_addr - prev_end_addr >= SZ_1GB) + return 1; + + prev_end_addr = end_addr; + + if (prot[0] != 'r') + continue; + + /* + * Confirm whether MAP_CHUNK_SIZE chunk can be found or not. + * If write succeeds, no need to check MAP_CHUNK_SIZE - 1 + * addresses after that. If the address was not held by this + * process, write would fail with errno set to EFAULT. + * Anyways, if write returns anything apart from 1, exit the + * program since that would mean a bug in /proc/self/maps. + */ + hop = 0; + while (start_addr + hop < end_addr) { + if (write(fd, (void *)(start_addr + hop), 1) != 1) + return 1; + else + lseek(fd, 0, SEEK_SET); + + hop += MAP_CHUNK_SIZE; + } + } + return 0; +} + int main(int argc, char *argv[]) { char *ptr[NR_CHUNKS_LOW]; @@ -135,6 +200,10 @@ int main(int argc, char *argv[]) validate_addr(hptr[i], 1); } hchunks = i; + if (validate_complete_va_space()) { + ksft_test_result_fail("BUG in mmap() or /proc/self/maps\n"); + ksft_finished(); + } for (i = 0; i < lchunks; i++) munmap(ptr[i], MAP_CHUNK_SIZE); -- 2.34.1

10 months

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[PATCH v1 0/5] Add support for the Idle HLT intercept feature

by Manali Shukla

The upcoming new Idle HLT Intercept feature allows for the HLT instruction execution by a vCPU to be intercepted by the hypervisor only if there are no pending V_INTR and V_NMI events for the vCPU. When the vCPU is expected to service the pending V_INTR and V_NMI events, the Idle HLT intercept won’t trigger. The feature allows the hypervisor to determine if the vCPU is actually idle and reduces wasteful VMEXITs. Presence of the Idle HLT Intercept feature is indicated via CPUID function Fn8000_000A_EDX[30]. Document for the Idle HLT intercept feature will be available in the next version of "AMD64 Architecture Programmer’s Manual". Testing Done: Added a selftest to test the Idle HLT intercept functionality. Tested SEV and SEV-ES guest for the Idle HLT intercept functionality. Manali Shukla (5): x86/cpufeatures: Add CPUID feature bit for Idle HLT intercept KVM: SVM: Add Idle HLT intercept support tools: Add KVM exit reason for the Idle HLT selftests: Add an interface to read the data of named vcpu stat selftests: KVM: SVM: Add Idle HLT intercept test arch/x86/include/asm/cpufeatures.h | 1 + arch/x86/include/asm/svm.h | 1 + arch/x86/include/uapi/asm/svm.h | 2 + arch/x86/kvm/svm/svm.c | 11 +- tools/arch/x86/include/uapi/asm/svm.h | 2 + tools/testing/selftests/kvm/Makefile | 1 + .../selftests/kvm/include/kvm_util_base.h | 11 ++ tools/testing/selftests/kvm/lib/kvm_util.c | 41 ++++++ .../selftests/kvm/x86_64/svm_idlehlt_test.c | 119 ++++++++++++++++++ 9 files changed, 186 insertions(+), 3 deletions(-) create mode 100644 tools/testing/selftests/kvm/x86_64/svm_idlehlt_test.c base-commit: fdd58834d132046149699b88a27a0db26829f4fb -- 2.34.1

10 months

2
12
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[PATCH] selftests/mm: Parse VMA range in one go

by Dev Jain

Use sscanf() to directly parse the VMA range. No functional change is intended. Signed-off-by: Dev Jain <dev.jain(a)arm.com> --- tools/testing/selftests/mm/mlock2-tests.c | 15 +-------------- 1 file changed, 1 insertion(+), 14 deletions(-) diff --git a/tools/testing/selftests/mm/mlock2-tests.c b/tools/testing/selftests/mm/mlock2-tests.c index 26f744188ad0..7f0d50fa361d 100644 --- a/tools/testing/selftests/mm/mlock2-tests.c +++ b/tools/testing/selftests/mm/mlock2-tests.c @@ -20,8 +20,6 @@ static int get_vm_area(unsigned long addr, struct vm_boundaries *area) FILE *file; int ret = 1; char line[1024] = {0}; - char *end_addr; - char *stop; unsigned long start; unsigned long end; @@ -37,21 +35,10 @@ static int get_vm_area(unsigned long addr, struct vm_boundaries *area) memset(area, 0, sizeof(struct vm_boundaries)); while(fgets(line, 1024, file)) { - end_addr = strchr(line, '-'); - if (!end_addr) { + if (sscanf(line, "%lx-%lx", &start, &end) != 2) { ksft_print_msg("cannot parse /proc/self/maps\n"); goto out; } - *end_addr = '\0'; - end_addr++; - stop = strchr(end_addr, ' '); - if (!stop) { - ksft_print_msg("cannot parse /proc/self/maps\n"); - goto out; - } - - sscanf(line, "%lx", &start); - sscanf(end_addr, "%lx", &end); if (start <= addr && end > addr) { area->start = start; -- 2.34.1

10 months

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[PATCH v1] selftests/mm: sigbus-wp test requires UFFD_FEATURE_WP_HUGETLBFS_SHMEM

by Edward Liaw

The sigbus-wp test requires the UFFD_FEATURE_WP_HUGETLBFS_SHMEM flag for shmem and hugetlb targets. Otherwise it is not backwards compatible with kernels <5.19 and fails with EINVAL. Signed-off-by: Edward Liaw <edliaw(a)google.com> --- tools/testing/selftests/mm/uffd-unit-tests.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/mm/uffd-unit-tests.c b/tools/testing/selftests/mm/uffd-unit-tests.c index 4a48dc617c6b..21ec23206ab4 100644 --- a/tools/testing/selftests/mm/uffd-unit-tests.c +++ b/tools/testing/selftests/mm/uffd-unit-tests.c @@ -1437,7 +1437,8 @@ uffd_test_case_t uffd_tests[] = { .uffd_fn = uffd_sigbus_wp_test, .mem_targets = MEM_ALL, .uffd_feature_required = UFFD_FEATURE_SIGBUS | - UFFD_FEATURE_EVENT_FORK | UFFD_FEATURE_PAGEFAULT_FLAG_WP, + UFFD_FEATURE_EVENT_FORK | UFFD_FEATURE_PAGEFAULT_FLAG_WP | + UFFD_FEATURE_WP_HUGETLBFS_SHMEM, }, { .name = "events", -- 2.44.0.396.g6e790dbe36-goog

10 months

2
1
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[PATCH v2] uffd-unit-tests: Fix ARM related issue with fork after pthread_create

by Edward Liaw

Following issue was observed while running the uffd-unit-tests selftest on ARM devices. On x86_64 no issues were detected: pthread_create followed by fork caused deadlock in certain cases wherein fork required some work to be completed by the created thread. Used synchronization to ensure that created thread's start function has started before invoking fork. Signed-off-by: Lokesh Gidra <lokeshgidra(a)google.com> [edliaw: Refactored to use atomic_bool] Signed-off-by: Edward Liaw <edliaw(a)google.com> --- tools/testing/selftests/mm/uffd-common.c | 3 +++ tools/testing/selftests/mm/uffd-common.h | 2 ++ tools/testing/selftests/mm/uffd-unit-tests.c | 10 ++++++++++ 3 files changed, 15 insertions(+) diff --git a/tools/testing/selftests/mm/uffd-common.c b/tools/testing/selftests/mm/uffd-common.c index b0ac0ec2356d..7ad6ba660c7d 100644 --- a/tools/testing/selftests/mm/uffd-common.c +++ b/tools/testing/selftests/mm/uffd-common.c @@ -18,6 +18,7 @@ bool test_uffdio_wp = true; unsigned long long *count_verify; uffd_test_ops_t *uffd_test_ops; uffd_test_case_ops_t *uffd_test_case_ops; +atomic_bool ready_for_fork; static int uffd_mem_fd_create(off_t mem_size, bool hugetlb) { @@ -518,6 +519,8 @@ void *uffd_poll_thread(void *arg) pollfd[1].fd = pipefd[cpu*2]; pollfd[1].events = POLLIN; + ready_for_fork = true; + for (;;) { ret = poll(pollfd, 2, -1); if (ret <= 0) { diff --git a/tools/testing/selftests/mm/uffd-common.h b/tools/testing/selftests/mm/uffd-common.h index cb055282c89c..cc5629c3d2aa 100644 --- a/tools/testing/selftests/mm/uffd-common.h +++ b/tools/testing/selftests/mm/uffd-common.h @@ -32,6 +32,7 @@ #include <inttypes.h> #include <stdint.h> #include <sys/random.h> +#include <stdatomic.h> #include "../kselftest.h" #include "vm_util.h" @@ -103,6 +104,7 @@ extern bool map_shared; extern bool test_uffdio_wp; extern unsigned long long *count_verify; extern volatile bool test_uffdio_copy_eexist; +extern atomic_bool ready_for_fork; extern uffd_test_ops_t anon_uffd_test_ops; extern uffd_test_ops_t shmem_uffd_test_ops; diff --git a/tools/testing/selftests/mm/uffd-unit-tests.c b/tools/testing/selftests/mm/uffd-unit-tests.c index 2b9f8cc52639..4a48dc617c6b 100644 --- a/tools/testing/selftests/mm/uffd-unit-tests.c +++ b/tools/testing/selftests/mm/uffd-unit-tests.c @@ -775,6 +775,8 @@ static void uffd_sigbus_test_common(bool wp) char c; struct uffd_args args = { 0 }; + ready_for_fork = false; + fcntl(uffd, F_SETFL, uffd_flags | O_NONBLOCK); if (uffd_register(uffd, area_dst, nr_pages * page_size, @@ -790,6 +792,9 @@ static void uffd_sigbus_test_common(bool wp) if (pthread_create(&uffd_mon, NULL, uffd_poll_thread, &args)) err("uffd_poll_thread create"); + while (!ready_for_fork) + ; /* Wait for the poll_thread to start executing before forking */ + pid = fork(); if (pid < 0) err("fork"); @@ -829,6 +834,8 @@ static void uffd_events_test_common(bool wp) char c; struct uffd_args args = { 0 }; + ready_for_fork = false; + fcntl(uffd, F_SETFL, uffd_flags | O_NONBLOCK); if (uffd_register(uffd, area_dst, nr_pages * page_size, true, wp, false)) @@ -838,6 +845,9 @@ static void uffd_events_test_common(bool wp) if (pthread_create(&uffd_mon, NULL, uffd_poll_thread, &args)) err("uffd_poll_thread create"); + while (!ready_for_fork) + ; /* Wait for the poll_thread to start executing before forking */ + pid = fork(); if (pid < 0) err("fork"); -- 2.44.0.396.g6e790dbe36-goog

10 months

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[BUG] selftests/net: test_vxlan_mdb.sh: 84 out of 642 tests [FAIL]

by Mirsad Todorovac

Hi, While running kselftest on vanilla torvalds tree kernel commit v6.8-11167-g4438a810f396, the test suite reported a number of errors. I was using the latest iproute2-next suite on an Ubuntu 22.04 LTS box. # Tests passed: 558 # Tests failed: 84 not ok 90 selftests: net: test_vxlan_mdb.sh # exit=1 495:# TEST: Destination IP - match [FAIL] 496:# TEST: Destination IP - no match [FAIL] 497:# TEST: Default destination port - match [FAIL] 498:# TEST: Default destination port - no match [FAIL] 499:# TEST: Non-default destination port - match [FAIL] 500:# TEST: Non-default destination port - no match [FAIL] 501:# TEST: Default destination VNI - match [FAIL] 502:# TEST: Default destination VNI - no match [FAIL] 503:# TEST: Non-default destination VNI - match [FAIL] 504:# TEST: Non-default destination VNI - no match [FAIL] 521:# TEST: Destination IP - match [FAIL] 522:# TEST: Destination IP - no match [FAIL] 523:# TEST: Default destination port - match [FAIL] 524:# TEST: Default destination port - no match [FAIL] 525:# TEST: Non-default destination port - match [FAIL] 526:# TEST: Non-default destination port - no match [FAIL] 527:# TEST: Default destination VNI - match [FAIL] 528:# TEST: Default destination VNI - no match [FAIL] 529:# TEST: Non-default destination VNI - match [FAIL] 530:# TEST: Non-default destination VNI - no match [FAIL] 549:# TEST: Forward valid source - first VTEP [FAIL] 550:# TEST: Forward valid source - second VTEP [FAIL] 551:# TEST: Block excluded source after removal - first VTEP [FAIL] 552:# TEST: Block excluded source after removal - second VTEP [FAIL] 553:# TEST: Forward valid source after removal - first VTEP [FAIL] 554:# TEST: Forward valid source after removal - second VTEP [FAIL] 571:# TEST: Forward valid source - first VTEP [FAIL] 572:# TEST: Forward valid source - second VTEP [FAIL] 573:# TEST: Block excluded source after removal - first VTEP [FAIL] 574:# TEST: Block excluded source after removal - second VTEP [FAIL] 575:# TEST: Forward valid source after removal - first VTEP [FAIL] 576:# TEST: Forward valid source after removal - second VTEP [FAIL] 593:# TEST: Forward valid source - first VTEP [FAIL] 594:# TEST: Forward valid source - second VTEP [FAIL] 595:# TEST: Block excluded source after removal - first VTEP [FAIL] 596:# TEST: Block excluded source after removal - second VTEP [FAIL] 597:# TEST: Forward valid source after removal - first VTEP [FAIL] 598:# TEST: Forward valid source after removal - second VTEP [FAIL] 615:# TEST: Forward valid source - first VTEP [FAIL] 616:# TEST: Forward valid source - second VTEP [FAIL] 617:# TEST: Block excluded source after removal - first VTEP [FAIL] 618:# TEST: Block excluded source after removal - second VTEP [FAIL] 619:# TEST: Forward valid source after removal - first VTEP [FAIL] 620:# TEST: Forward valid source after removal - second VTEP [FAIL] 636:# TEST: Forward valid source [FAIL] 637:# TEST: Receive of valid source after removal from group [FAIL] 648:# TEST: Forward valid source [FAIL] 649:# TEST: Receive of valid source after removal from group [FAIL] 660:# TEST: Forward valid source [FAIL] 661:# TEST: Receive of valid source after removal from group [FAIL] 672:# TEST: Forward valid source [FAIL] 673:# TEST: Receive of valid source after removal from group [FAIL] 683:# TEST: Egress VNI translation - PVID configured [FAIL] 684:# TEST: Egress VNI translation - no PVID configured [FAIL] 685:# TEST: Egress VNI translation - PVID reconfigured [FAIL] 695:# TEST: Egress VNI translation - PVID configured [FAIL] 696:# TEST: Egress VNI translation - no PVID configured [FAIL] 697:# TEST: Egress VNI translation - PVID reconfigured [FAIL] 707:# TEST: Registered IPv4 multicast - first VTEP [FAIL] 709:# TEST: Unregistered IPv4 multicast - first VTEP [FAIL] 710:# TEST: Unregistered IPv4 multicast - second VTEP [FAIL] 711:# TEST: Link-local IPv4 multicast - first VTEP [FAIL] 712:# TEST: Link-local IPv4 multicast - second VTEP [FAIL] 713:# TEST: Registered IPv4 multicast with a unicast MAC - first VTEP [FAIL] 714:# TEST: Registered IPv4 multicast with a unicast MAC - second VTEP [FAIL] 715:# TEST: Registered IPv4 multicast with a broadcast MAC - first VTEP [FAIL] 716:# TEST: Registered IPv4 multicast with a broadcast MAC - second VTEP [FAIL] 734:# TEST: Registered IPv4 multicast - first VTEP [FAIL] 736:# TEST: Unregistered IPv4 multicast - first VTEP [FAIL] 737:# TEST: Unregistered IPv4 multicast - second VTEP [FAIL] 738:# TEST: Link-local IPv4 multicast - first VTEP [FAIL] 739:# TEST: Link-local IPv4 multicast - second VTEP [FAIL] 740:# TEST: Registered IPv4 multicast with a unicast MAC - first VTEP [FAIL] 741:# TEST: Registered IPv4 multicast with a unicast MAC - second VTEP [FAIL] 742:# TEST: Registered IPv4 multicast with a broadcast MAC - first VTEP [FAIL] 743:# TEST: Registered IPv4 multicast with a broadcast MAC - second VTEP [FAIL] 761:# TEST: IP multicast - first VTEP [FAIL] 763:# TEST: Broadcast - first VTEP [FAIL] 765:# TEST: IP multicast after removal - first VTEP [FAIL] 766:# TEST: IP multicast after removal - second VTEP [FAIL] 779:# TEST: IP multicast - first VTEP [FAIL] 781:# TEST: Broadcast - first VTEP [FAIL] 783:# TEST: IP multicast after removal - first VTEP [FAIL] 784:# TEST: IP multicast after removal - second VTEP [FAIL] The problem is present at least since 6.8-rc7. Please find attached the config and the full output of test_vxlan_mdb.sh. Hope this helps. Best regards, Mirsad Todorovac

10 months

3
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[PATCH v1] uffd-unit-tests: Fix ARM related issue with fork after pthread_create

by Edward Liaw

Following issue was observed while running the uffd-unit-tests selftest on ARM devices. On x86_64 no issues were detected: pthread_create followed by fork caused deadlock in certain cases wherein fork required some work to be completed by the created thread. Used synchronization to ensure that created thread's start function has started before invoking fork. Signed-off-by: Lokesh Gidra <lokeshgidra(a)google.com> [edliaw: Refactored to use atomic_bool] Signed-off-by: Edward Liaw <edliaw(a)google.com> --- tools/testing/selftests/mm/uffd-common.c | 4 +++- tools/testing/selftests/mm/uffd-common.h | 2 ++ tools/testing/selftests/mm/uffd-unit-tests.c | 10 ++++++++++ 3 files changed, 15 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/mm/uffd-common.c b/tools/testing/selftests/mm/uffd-common.c index b0ac0ec2356d..14ed98c3a389 100644 --- 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; -uffd_test_case_ops_t *uffd_test_case_ops; +atomic_bool ready_for_fork; static int uffd_mem_fd_create(off_t mem_size, bool hugetlb) { @@ -518,6 +518,8 @@ void *uffd_poll_thread(void *arg) pollfd[1].fd = pipefd[cpu*2]; pollfd[1].events = POLLIN; + ready_for_fork = true; + for (;;) { ret = poll(pollfd, 2, -1); if (ret <= 0) { diff --git a/tools/testing/selftests/mm/uffd-common.h b/tools/testing/selftests/mm/uffd-common.h index cb055282c89c..cc5629c3d2aa 100644 --- a/tools/testing/selftests/mm/uffd-common.h +++ b/tools/testing/selftests/mm/uffd-common.h @@ -32,6 +32,7 @@ #include <inttypes.h> #include <stdint.h> #include <sys/random.h> +#include <stdatomic.h> #include "../kselftest.h" #include "vm_util.h" @@ -103,6 +104,7 @@ extern bool map_shared; extern bool test_uffdio_wp; extern unsigned long long *count_verify; extern volatile bool test_uffdio_copy_eexist; +extern atomic_bool ready_for_fork; extern uffd_test_ops_t anon_uffd_test_ops; extern uffd_test_ops_t shmem_uffd_test_ops; diff --git a/tools/testing/selftests/mm/uffd-unit-tests.c b/tools/testing/selftests/mm/uffd-unit-tests.c index 2b9f8cc52639..4a48dc617c6b 100644 --- a/tools/testing/selftests/mm/uffd-unit-tests.c +++ b/tools/testing/selftests/mm/uffd-unit-tests.c @@ -775,6 +775,8 @@ static void uffd_sigbus_test_common(bool wp) char c; struct uffd_args args = { 0 }; + ready_for_fork = false; + fcntl(uffd, F_SETFL, uffd_flags | O_NONBLOCK); if (uffd_register(uffd, area_dst, nr_pages * page_size, @@ -790,6 +792,9 @@ static void uffd_sigbus_test_common(bool wp) if (pthread_create(&uffd_mon, NULL, uffd_poll_thread, &args)) err("uffd_poll_thread create"); + while (!ready_for_fork) + ; /* Wait for the poll_thread to start executing before forking */ + pid = fork(); if (pid < 0) err("fork"); @@ -829,6 +834,8 @@ static void uffd_events_test_common(bool wp) char c; struct uffd_args args = { 0 }; + ready_for_fork = false; + fcntl(uffd, F_SETFL, uffd_flags | O_NONBLOCK); if (uffd_register(uffd, area_dst, nr_pages * page_size, true, wp, false)) @@ -838,6 +845,9 @@ static void uffd_events_test_common(bool wp) if (pthread_create(&uffd_mon, NULL, uffd_poll_thread, &args)) err("uffd_poll_thread create"); + while (!ready_for_fork) + ; /* Wait for the poll_thread to start executing before forking */ + pid = fork(); if (pid < 0) err("fork"); -- 2.44.0.396.g6e790dbe36-goog

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[PATCH bpf-next v4 0/6] sleepable bpf_timer (was: allow HID-BPF to do device IOs)

by Benjamin Tissoires

New version of the sleepable bpf_timer code, without the HID changes, as they can now go through the HID tree independantly. For reference, the use cases I have in mind: --- Basically, I need to be able to defer a HID-BPF program for the following reasons (from the aforementioned patch): 1. defer an event: Sometimes we receive an out of proximity event, but the device can not be trusted enough, and we need to ensure that we won't receive another one in the following n milliseconds. So we need to wait those n milliseconds, and eventually re-inject that event in the stack. 2. inject new events in reaction to one given event: We might want to transform one given event into several. This is the case for macro keys where a single key press is supposed to send a sequence of key presses. But this could also be used to patch a faulty behavior, if a device forgets to send a release event. 3. communicate with the device in reaction to one event: We might want to communicate back to the device after a given event. For example a device might send us an event saying that it came back from sleeping state and needs to be re-initialized. Currently we can achieve that by keeping a userspace program around, raise a bpf event, and let that userspace program inject the events and commands. However, we are just keeping that program alive as a daemon for just scheduling commands. There is no logic in it, so it doesn't really justify an actual userspace wakeup. So a kernel workqueue seems simpler to handle. bpf_timers are currently running in a soft IRQ context, this patch series implements a sleppable context for them. Cheers, Benjamin To: Alexei Starovoitov <ast(a)kernel.org> To: Daniel Borkmann <daniel(a)iogearbox.net> To: Andrii Nakryiko <andrii(a)kernel.org> To: Martin KaFai Lau <martin.lau(a)linux.dev> To: Eduard Zingerman <eddyz87(a)gmail.com> To: Song Liu <song(a)kernel.org> To: Yonghong Song <yonghong.song(a)linux.dev> To: John Fastabend <john.fastabend(a)gmail.com> To: KP Singh <kpsingh(a)kernel.org> To: Stanislav Fomichev <sdf(a)google.com> To: Hao Luo <haoluo(a)google.com> To: Jiri Olsa <jolsa(a)kernel.org> To: Mykola Lysenko <mykolal(a)fb.com> To: Shuah Khan <shuah(a)kernel.org> Cc: Benjamin Tissoires <bentiss(a)kernel.org> Cc: <bpf(a)vger.kernel.org> Cc: <linux-kernel(a)vger.kernel.org> Cc: <linux-kselftest(a)vger.kernel.org> --- Changes in v4: - dropped the HID changes, they can go independently from bpf-core - addressed Alexei's and Eduard's remarks - added selftests - Link to v3: https://lore.kernel.org/r/20240221-hid-bpf-sleepable-v3-0-1fb378ca6301@kern… Changes in v3: - fixed the crash from v2 - changed the API to have only BPF_F_TIMER_SLEEPABLE for bpf_timer_start() - split the new kfuncs/verifier patch into several sub-patches, for easier reviews - Link to v2: https://lore.kernel.org/r/20240214-hid-bpf-sleepable-v2-0-5756b054724d@kern… Changes in v2: - make use of bpf_timer (and dropped the custom HID handling) - implemented bpf_timer_set_sleepable_cb as a kfunc - still not implemented global subprogs - no sleepable bpf_timer selftests yet - Link to v1: https://lore.kernel.org/r/20240209-hid-bpf-sleepable-v1-0-4cc895b5adbd@kern… --- Benjamin Tissoires (6): bpf/helpers: introduce sleepable bpf_timers bpf/verifier: add bpf_timer as a kfunc capable type bpf/helpers: introduce bpf_timer_set_sleepable_cb() kfunc bpf/helpers: mark the callback of bpf_timer_set_sleepable_cb() as sleepable tools: sync include/uapi/linux/bpf.h selftests/bpf: add sleepable timer tests include/linux/bpf_verifier.h | 1 + include/uapi/linux/bpf.h | 4 + kernel/bpf/helpers.c | 132 ++++++++++++++++++++- kernel/bpf/verifier.c | 92 +++++++++++++- tools/include/uapi/linux/bpf.h | 4 + tools/testing/selftests/bpf/bpf_experimental.h | 4 + .../selftests/bpf/bpf_testmod/bpf_testmod.c | 5 + .../selftests/bpf/bpf_testmod/bpf_testmod_kfunc.h | 1 + tools/testing/selftests/bpf/prog_tests/timer.c | 1 + tools/testing/selftests/bpf/progs/timer.c | 40 ++++++- tools/testing/selftests/bpf/progs/timer_failure.c | 114 +++++++++++++++++- 11 files changed, 387 insertions(+), 11 deletions(-) --- base-commit: 9187210eee7d87eea37b45ea93454a88681894a4 change-id: 20240205-hid-bpf-sleepable-c01260fd91c4 Best regards, -- Benjamin Tissoires <bentiss(a)kernel.org>

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