- Linux-kselftest-mirror - lists.linaro.org

[PATCH] selftest/futex: fix format-security warnings in futex_priv_hash

by Nai-Chen Cheng

Fix format-security warnings by using proper format strings when passing message variables to ksft_exit_fail_msg(), ksft_test_result_pass(), and ksft_test_result_skip() function. This prevents potential security issues and eliminates compiler warnings when building with -Wformat-security. Signed-off-by: Nai-Chen Cheng <bleach1827(a)gmail.com> --- .../selftests/futex/functional/futex_priv_hash.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/tools/testing/selftests/futex/functional/futex_priv_hash.c b/tools/testing/selftests/futex/functional/futex_priv_hash.c index 24a92dc94eb8..19651087c4de 100644 --- a/tools/testing/selftests/futex/functional/futex_priv_hash.c +++ b/tools/testing/selftests/futex/functional/futex_priv_hash.c @@ -184,10 +184,10 @@ int main(int argc, char *argv[]) futex_slots1 = futex_hash_slots_get(); if (futex_slots1 <= 0) { ksft_print_msg("Current hash buckets: %d\n", futex_slots1); - ksft_exit_fail_msg(test_msg_auto_create); + ksft_exit_fail_msg("%s", test_msg_auto_create); } - ksft_test_result_pass(test_msg_auto_create); + ksft_test_result_pass("%s", test_msg_auto_create); online_cpus = sysconf(_SC_NPROCESSORS_ONLN); ret = pthread_barrier_init(&barrier_main, NULL, MAX_THREADS + 1); @@ -212,11 +212,11 @@ int main(int argc, char *argv[]) if (futex_slotsn < 0 || futex_slots1 == futex_slotsn) { ksft_print_msg("Expected increase of hash buckets but got: %d -> %d\n", futex_slots1, futex_slotsn); - ksft_exit_fail_msg(test_msg_auto_inc); + ksft_exit_fail_msg("%s", test_msg_auto_inc); } - ksft_test_result_pass(test_msg_auto_inc); + ksft_test_result_pass("%s", test_msg_auto_inc); } else { - ksft_test_result_skip(test_msg_auto_inc); + ksft_test_result_skip("%s", test_msg_auto_inc); } ret = pthread_mutex_unlock(&global_lock); -- 2.43.0

5 months, 1 week

1
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[PATCH] kselftest/arm4: Provide local defines for AT_HWCAP3

by Mark Brown

Some build environments for the selftests are not picking up the newly added AT_HWCAP3 when using the libc headers, even with headers_install (which we require already for the arm64 selftests). As a quick fix add local definitions of the constant to tools use it, while auxvec.h is installed with some toolchains it needs some persuasion to get picked up. Signed-off-by: Mark Brown <broonie(a)kernel.org> --- tools/testing/selftests/arm64/abi/hwcap.c | 4 ++++ tools/testing/selftests/arm64/mte/check_prctl.c | 4 ++++ 2 files changed, 8 insertions(+) diff --git a/tools/testing/selftests/arm64/abi/hwcap.c b/tools/testing/selftests/arm64/abi/hwcap.c index 35f521e5f41c..aa902408facd 100644 --- a/tools/testing/selftests/arm64/abi/hwcap.c +++ b/tools/testing/selftests/arm64/abi/hwcap.c @@ -21,6 +21,10 @@ #define TESTS_PER_HWCAP 3 +#ifndef AT_HWCAP3 +#define AT_HWCAP3 29 +#endif + /* * Function expected to generate exception when the feature is not * supported and return when it is supported. If the specific exception diff --git a/tools/testing/selftests/arm64/mte/check_prctl.c b/tools/testing/selftests/arm64/mte/check_prctl.c index 4c89e9538ca0..c36c4c49ff95 100644 --- a/tools/testing/selftests/arm64/mte/check_prctl.c +++ b/tools/testing/selftests/arm64/mte/check_prctl.c @@ -12,6 +12,10 @@ #include "kselftest.h" +#ifndef AT_HWCAP3 +#define AT_HWCAP3 29 +#endif + static int set_tagged_addr_ctrl(int val) { int ret; --- base-commit: 86731a2a651e58953fc949573895f2fa6d456841 change-id: 20250710-arm64-selftest-bodge-hwcap3-b6ab30ab69cd Best regards, -- Mark Brown <broonie(a)kernel.org>

5 months, 1 week

3
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[PATCH v9 00/29] iommufd: Add vIOMMU infrastructure (Part-4 HW QUEUE)

by Nicolin Chen

The vIOMMU object is designed to represent a slice of an IOMMU HW for its virtualization features shared with or passed to user space (a VM mostly) in a way of HW acceleration. This extended the HWPT-based design for more advanced virtualization feature. HW QUEUE introduced by this series as a part of the vIOMMU infrastructure represents a HW accelerated queue/buffer for VM to use exclusively, e.g. - NVIDIA's Virtual Command Queue - AMD vIOMMU's Command Buffer, Event Log Buffer, and PPR Log Buffer each of which allows its IOMMU HW to directly access a queue memory owned by a guest VM and allows a guest OS to control the HW queue direclty, to avoid VM Exit overheads to improve the performance. Introduce IOMMUFD_OBJ_HW_QUEUE and its pairing IOMMUFD_CMD_HW_QUEUE_ALLOC allowing VMM to forward the IOMMU-specific queue info, such as queue base address, size, and etc. Meanwhile, a guest-owned queue needs the guest kernel to control the queue by reading/writing its consumer and producer indexes, via MMIO acceses to the hardware MMIO registers. Introduce an mmap infrastructure for iommufd to support passing through a piece of MMIO region from the host physical address space to the guest physical address space. The mmap info (offset/ length) used by an mmap syscall must be pre-allocated and returned to the user space via an output driver-data during an IOMMUFD_CMD_HW_QUEUE_ALLOC call. Thus, it requires a driver-specific user data support in the vIOMMU allocation flow. As a real-world use case, this series implements a HW QUEUE support in the tegra241-cmdqv driver for VCMDQs on NVIDIA Grace CPU. In another word, it is also the Tegra CMDQV series Part-2 (user-space support), reworked from Previous RFCv1: https://lore.kernel.org/all/cover.1712978212.git.nicolinc@nvidia.com/ This enables the HW accelerated feature for NVIDIA Grace CPU. Compared to the standard SMMUv3 operating in the nested translation mode trapping CMDQ for TLBI and ATC_INV commands, this gives a huge performance improvement: 70% to 90% reductions of invalidation time were measured by various DMA unmap tests running in a guest OS. // Unmap latencies from "dma_map_benchmark -g @granule -t @threads", // by toggling "/sys/kernel/debug/iommu/tegra241_cmdqv/bypass_vcmdq" @granule | @threads | bypass_vcmdq=1 | bypass_vcmdq=0 4KB 1 35.7 us 5.3 us 16KB 1 41.8 us 6.8 us 64KB 1 68.9 us 9.9 us 128KB 1 109.0 us 12.6 us 256KB 1 187.1 us 18.0 us 4KB 2 96.9 us 6.8 us 16KB 2 97.8 us 7.5 us 64KB 2 151.5 us 10.7 us 128KB 2 257.8 us 12.7 us 256KB 2 443.0 us 17.9 us This is on Github: https://github.com/nicolinc/iommufd/commits/iommufd_hw_queue-v9 Paring QEMU branch for testing (reusing v8): https://github.com/nicolinc/qemu/commits/wip/for_iommufd_hw_queue-v8 Changelog v9 (attached git-diff v8..v9 at the end of this letter) * Add Reviewed-by from Vasant and Jason * [iommufd] Fix offset calculation * [iommufd] Add unaligned iova/length selftest coverage for hw_queue * [iommufd] Pass in aligned iova/length to iommufd_access_pin_pages() * [smmu] Change "u32 *type" at arm_smmu_hw_info() in the header v8 https://lore.kernel.org/all/cover.1751677708.git.nicolinc@nvidia.com/ * Add Reviewed-by from Pranj, Kevin and Jason * Improve kdoc and comments * [iommufd] Skip selftest for no_viommu variants * [iommufd] Add unmap coverage for non internal area * [iommufd] Skip the first page when mtree_alloc_range() * [iommufd] Correct the passed in index to mtree_erase() * [iommufd] Correct variable types in iommufd_hw_queue_alloc_phys() * [iommufd] Reject iopt_unmap_iova_range() if area->num_locks is set * [tegra] Rename "SID replacement" with "SID mapping" * [tegra] Unwrap useless _tegra241_vcmdq_hw_init helper v7 https://lore.kernel.org/all/cover.1750966133.git.nicolinc@nvidia.com/ * Rebased on Jason's for-next tree (iommufd_hw_queue-prep series) * Add Reviewed-by from Baolu, Jason, Pranjal * Update kdocs and notes * [iommu] Replace "u32" with "enum iommu_hw_info_type" * [iommufd] Rename vdev->id to vdev->virt_id * [iommufd] Replace macros with inline helpers * [iommufd] Report unmapped_bytes in error path * [iommufd] Add iommufd_access_is_internal helper * [iommufd] Do not drop ops->unmap check for mdevs * [iommufd] Store physical addresses in immap structure * [iommufd] Reorder access and hw_queue object allocations * [iommufd] Scan for an internal access before any unmap call * [iommufd] Drop unused ictx pointer in struct iommufd_hw_queue * [iommufd] Use kcalloc to avoid failure due to memory fragmentation * [tegra] Use "else" * [tegra] Lock destroy() using lvcmdq_mutex v6 https://lore.kernel.org/all/cover.1749884998.git.nicolinc@nvidia.com/ * Rebase on iommufd_hw_queue-prep-v2 * Add Reviewed-by from Kevin and Jason * [iommufd] Update kdocs and notes * [iommufd] Drop redundant pages[i] check * [iommufd] Allow nesting_parent_iova to be 0 * [iommufd] Add iommufd_hw_queue_alloc_phys() * [iommufd] Revise iommufd_viommu_alloc/destroy_mmap APIs * [iommufd] Move destroy ops to vdevice/hw_queue structures * [iommufd] Add union in hw_info struct to share out_data_type field * [iommufd] Replace iopt_pin/unpin_pages() with internal access APIs * [iommufd] Replace vdevice_alloc with vdevice_size and vdevice_init * [iommufd] Replace hw_queue_alloc with get_hw_queue_size/hw_queue_init * [iommufd] Replace IOMMUFD_VIOMMU_FLAG_HW_QUEUE_READS_PA with init_phys * [smmu] Drop arm_smmu_domain_ipa_to_pa * [smmu] Update arm_smmu_impl_ops changes for vsmmu_init * [tegra] Add a vdev_to_vsid macro * [tegra] Add lvcmdq_mutex to protect multi queues * [tegra] Drop duplicated kcalloc for vintf->lvcmdqs (memory leak) v5 https://lore.kernel.org/all/cover.1747537752.git.nicolinc@nvidia.com/ * Rebase on v6.15-rc6 * Add Reviewed-by from Jason and Kevin * Correct typos in kdoc and update commit logs * [iommufd] Add a cosmetic fix * [iommufd] Drop unused num_pfns * [iommufd] Drop unnecessary check * [iommufd] Reorder patch sequence * [iommufd] Use io_remap_pfn_range() * [iommufd] Use success oriented flow * [iommufd] Fix max_npages calculation * [iommufd] Add more selftest coverage * [iommufd] Drop redundant static_assert * [iommufd] Fix mmap pfn range validation * [iommufd] Reject unmap on pinned iovas * [iommufd] Drop redundant vm_flags_set() * [iommufd] Drop iommufd_struct_destroy() * [iommufd] Drop redundant queue iova test * [iommufd] Use "mmio_addr" and "mmio_pfn" * [iommufd] Rename to "nesting_parent_iova" * [iommufd] Make iopt_pin_pages call option * [iommufd] Add ictx comparison in depend() * [iommufd] Add iommufd_object_alloc_ucmd() * [iommufd] Move kcalloc() after validations * [iommufd] Replace ictx setting with WARN_ON * [iommufd] Make hw_info's type bidirectional * [smmu] Add supported_vsmmu_type in impl_ops * [smmu] Drop impl report in smmu vendor struct * [tegra] Add IOMMU_HW_INFO_TYPE_TEGRA241_CMDQV * [tegra] Replace "number of VINTFs" with a note * [tegra] Drop the redundant lvcmdq pointer setting * [tegra] Flag IOMMUFD_VIOMMU_FLAG_HW_QUEUE_READS_PA * [tegra] Use "vintf_alloc_vsid" for vdevice_alloc op v4 https://lore.kernel.org/all/cover.1746757630.git.nicolinc@nvidia.com/ * Rebase on v6.15-rc5 * Add Reviewed-by from Vasant * Rename "vQUEUE" to "HW QUEUE" * Use "offset" and "length" for all mmap-related variables * [iommufd] Use u64 for guest PA * [iommufd] Fix typo in uAPI doc * [iommufd] Rename immap_id to offset * [iommufd] Drop the partial-size mmap support * [iommufd] Do not replace WARN_ON with WARN_ON_ONCE * [iommufd] Use "u64 base_addr" for queue base address * [iommufd] Use u64 base_pfn/num_pfns for immap structure * [iommufd] Correct the size passed in to mtree_alloc_range() * [iommufd] Add IOMMUFD_VIOMMU_FLAG_HW_QUEUE_READS_PA to viommu_ops v3 https://lore.kernel.org/all/cover.1746139811.git.nicolinc@nvidia.com/ * Add Reviewed-by from Baolu, Pranjal, and Alok * Revise kdocs, uAPI docs, and commit logs * Rename "vCMDQ" back to "vQUEUE" for AMD cases * [tegra] Add tegra241_vcmdq_hw_flush_timeout() * [tegra] Rename vsmmu_alloc to alloc_vintf_user * [tegra] Use writel for SID replacement registers * [tegra] Move mmap removal call to vsmmu_destroy op * [tegra] Fix revert in tegra241_vintf_alloc_lvcmdq_user() * [iommufd] Replace "& ~PAGE_MASK" with PAGE_ALIGNED() * [iommufd] Add an object-type "owner" to immap structure * [iommufd] Drop the ictx input in the new for-driver APIs * [iommufd] Add iommufd_vma_ops to keep track of mmap lifecycle * [iommufd] Add viommu-based iommufd_viommu_alloc/destroy_mmap helpers * [iommufd] Rename iommufd_ctx_alloc/free_mmap to _iommufd_alloc/destroy_mmap v2 https://lore.kernel.org/all/cover.1745646960.git.nicolinc@nvidia.com/ * Add Reviewed-by from Jason * [smmu] Fix vsmmu initial value * [smmu] Support impl for hw_info * [tegra] Rename "slot" to "vsid" * [tegra] Update kdocs and commit logs * [tegra] Map/unmap LVCMDQ dynamically * [tegra] Refcount the previous LVCMDQ * [tegra] Return -EEXIST if LVCMDQ exists * [tegra] Simplify VINTF cleanup routine * [tegra] Use vmid and s2_domain in vsmmu * [tegra] Rename "mmap_pgoff" to "immap_id" * [tegra] Add more addr and length validation * [iommufd] Add more narrative to mmap's kdoc * [iommufd] Add iommufd_struct_depend/undepend() * [iommufd] Rename vcmdq_free op to vcmdq_destroy * [iommufd] Fix bug in iommu_copy_struct_to_user() * [iommufd] Drop is_io from iommufd_ctx_alloc_mmap() * [iommufd] Test the queue memory for its contiguity * [iommufd] Return -ENXIO if address or length fails * [iommufd] Do not change @min_last in mock_viommu_alloc() * [iommufd] Generalize TEGRA241_VCMDQ data in core structure * [iommufd] Add selftest coverage for IOMMUFD_CMD_VCMDQ_ALLOC * [iommufd] Add iopt_pin_pages() to prevent queue memory from unmapping v1 https://lore.kernel.org/all/cover.1744353300.git.nicolinc@nvidia.com/ Thanks Nicolin Nicolin Chen (29): iommufd: Report unmapped bytes in the error path of iopt_unmap_iova_range iommufd: Correct virt_id kdoc at struct iommu_vdevice_alloc iommufd/viommu: Explicitly define vdev->virt_id iommu: Use enum iommu_hw_info_type for type in hw_info op iommu: Add iommu_copy_struct_to_user helper iommu: Pass in a driver-level user data structure to viommu_init op iommufd/viommu: Allow driver-specific user data for a vIOMMU object iommufd/selftest: Support user_data in mock_viommu_alloc iommufd/selftest: Add coverage for viommu data iommufd/access: Add internal APIs for HW queue to use iommufd/access: Bypass access->ops->unmap for internal use iommufd/viommu: Add driver-defined vDEVICE support iommufd/viommu: Introduce IOMMUFD_OBJ_HW_QUEUE and its related struct iommufd/viommu: Add IOMMUFD_CMD_HW_QUEUE_ALLOC ioctl iommufd/driver: Add iommufd_hw_queue_depend/undepend() helpers iommufd/selftest: Add coverage for IOMMUFD_CMD_HW_QUEUE_ALLOC iommufd: Add mmap interface iommufd/selftest: Add coverage for the new mmap interface Documentation: userspace-api: iommufd: Update HW QUEUE iommu: Allow an input type in hw_info op iommufd: Allow an input data_type via iommu_hw_info iommufd/selftest: Update hw_info coverage for an input data_type iommu/arm-smmu-v3-iommufd: Add vsmmu_size/type and vsmmu_init impl ops iommu/arm-smmu-v3-iommufd: Add hw_info to impl_ops iommu/tegra241-cmdqv: Use request_threaded_irq iommu/tegra241-cmdqv: Simplify deinit flow in tegra241_cmdqv_remove_vintf() iommu/tegra241-cmdqv: Do not statically map LVCMDQs iommu/tegra241-cmdqv: Add user-space use support iommu/tegra241-cmdqv: Add IOMMU_VEVENTQ_TYPE_TEGRA241_CMDQV support drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 25 +- drivers/iommu/iommufd/io_pagetable.h | 5 +- drivers/iommu/iommufd/iommufd_private.h | 46 +- drivers/iommu/iommufd/iommufd_test.h | 20 + include/linux/iommu.h | 50 +- include/linux/iommufd.h | 160 ++++++ include/uapi/linux/iommufd.h | 147 +++++- tools/testing/selftests/iommu/iommufd_utils.h | 89 +++- .../arm/arm-smmu-v3/arm-smmu-v3-iommufd.c | 28 +- .../iommu/arm/arm-smmu-v3/tegra241-cmdqv.c | 477 +++++++++++++++++- drivers/iommu/intel/iommu.c | 7 +- drivers/iommu/iommufd/device.c | 87 +++- drivers/iommu/iommufd/driver.c | 82 ++- drivers/iommu/iommufd/io_pagetable.c | 13 +- drivers/iommu/iommufd/main.c | 69 +++ drivers/iommu/iommufd/pages.c | 12 +- drivers/iommu/iommufd/selftest.c | 153 +++++- drivers/iommu/iommufd/viommu.c | 218 +++++++- tools/testing/selftests/iommu/iommufd.c | 141 +++++- .../selftests/iommu/iommufd_fail_nth.c | 15 +- Documentation/userspace-api/iommufd.rst | 12 + 21 files changed, 1745 insertions(+), 111 deletions(-) -- 2.43.0 diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h index aa25156e04a3..3fa02c51df9f 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h @@ -1045,7 +1045,8 @@ struct arm_vsmmu { }; #if IS_ENABLED(CONFIG_ARM_SMMU_V3_IOMMUFD) -void *arm_smmu_hw_info(struct device *dev, u32 *length, u32 *type); +void *arm_smmu_hw_info(struct device *dev, u32 *length, + enum iommu_hw_info_type *type); size_t arm_smmu_get_viommu_size(struct device *dev, enum iommu_viommu_type viommu_type); int arm_vsmmu_init(struct iommufd_viommu *viommu, diff --git a/drivers/iommu/iommufd/viommu.c b/drivers/iommu/iommufd/viommu.c index 00641204efb2..91339f799916 100644 --- a/drivers/iommu/iommufd/viommu.c +++ b/drivers/iommu/iommufd/viommu.c @@ -206,7 +206,11 @@ static void iommufd_hw_queue_destroy_access(struct iommufd_ctx *ictx, struct iommufd_access *access, u64 base_iova, size_t length) { - iommufd_access_unpin_pages(access, base_iova, length); + u64 aligned_iova = PAGE_ALIGN_DOWN(base_iova); + u64 offset = base_iova - aligned_iova; + + iommufd_access_unpin_pages(access, aligned_iova, + PAGE_ALIGN(length + offset)); iommufd_access_detach_internal(access); iommufd_access_destroy_internal(ictx, access); } @@ -239,22 +243,23 @@ static struct iommufd_access * iommufd_hw_queue_alloc_phys(struct iommu_hw_queue_alloc *cmd, struct iommufd_viommu *viommu, phys_addr_t *base_pa) { + u64 aligned_iova = PAGE_ALIGN_DOWN(cmd->nesting_parent_iova); + u64 offset = cmd->nesting_parent_iova - aligned_iova; struct iommufd_access *access; struct page **pages; size_t max_npages; size_t length; - u64 offset; size_t i; int rc; - offset = - cmd->nesting_parent_iova - PAGE_ALIGN(cmd->nesting_parent_iova); - /* DIV_ROUND_UP(offset + cmd->length, PAGE_SIZE) */ + /* max_npages = DIV_ROUND_UP(offset + cmd->length, PAGE_SIZE) */ if (check_add_overflow(offset, cmd->length, &length)) return ERR_PTR(-ERANGE); if (check_add_overflow(length, PAGE_SIZE - 1, &length)) return ERR_PTR(-ERANGE); max_npages = length / PAGE_SIZE; + /* length needs to be page aligned too */ + length = max_npages * PAGE_SIZE; /* * Use kvcalloc() to avoid memory fragmentation for a large page array. @@ -274,8 +279,7 @@ iommufd_hw_queue_alloc_phys(struct iommu_hw_queue_alloc *cmd, if (rc) goto out_destroy; - rc = iommufd_access_pin_pages(access, cmd->nesting_parent_iova, - cmd->length, pages, 0); + rc = iommufd_access_pin_pages(access, aligned_iova, length, pages, 0); if (rc) goto out_detach; @@ -287,13 +291,12 @@ iommufd_hw_queue_alloc_phys(struct iommu_hw_queue_alloc *cmd, goto out_unpin; } - *base_pa = page_to_pfn(pages[0]) << PAGE_SHIFT; + *base_pa = (page_to_pfn(pages[0]) << PAGE_SHIFT) + offset; kfree(pages); return access; out_unpin: - iommufd_access_unpin_pages(access, cmd->nesting_parent_iova, - cmd->length); + iommufd_access_unpin_pages(access, aligned_iova, length); out_detach: iommufd_access_detach_internal(access); out_destroy: diff --git a/tools/testing/selftests/iommu/iommufd.c b/tools/testing/selftests/iommu/iommufd.c index 9d5b852d5e19..d59d48022a24 100644 --- a/tools/testing/selftests/iommu/iommufd.c +++ b/tools/testing/selftests/iommu/iommufd.c @@ -3104,17 +3104,18 @@ TEST_F(iommufd_viommu, hw_queue) /* Allocate index=0, declare ownership of the iova */ test_cmd_hw_queue_alloc(viommu_id, IOMMU_HW_QUEUE_TYPE_SELFTEST, 0, iova, PAGE_SIZE, &hw_queue_id[0]); - /* Fail duplicate */ + /* Fail duplicated index */ test_err_hw_queue_alloc(EEXIST, viommu_id, IOMMU_HW_QUEUE_TYPE_SELFTEST, 0, iova, PAGE_SIZE, &hw_queue_id[0]); /* Fail unmap, due to iova ownership */ test_err_ioctl_ioas_unmap(EBUSY, iova, PAGE_SIZE); /* The 2nd page is not pinned, so it can be unmmap */ - test_ioctl_ioas_unmap(iova + PAGE_SIZE, PAGE_SIZE); + test_ioctl_ioas_unmap(iova2, PAGE_SIZE); - /* Allocate index=1 */ + /* Allocate index=1, with an unaligned case */ test_cmd_hw_queue_alloc(viommu_id, IOMMU_HW_QUEUE_TYPE_SELFTEST, 1, - iova, PAGE_SIZE, &hw_queue_id[1]); + iova + PAGE_SIZE / 2, PAGE_SIZE / 2, + &hw_queue_id[1]); /* Fail to destroy, due to dependency */ EXPECT_ERRNO(EBUSY, _test_ioctl_destroy(self->fd, hw_queue_id[0]));

5 months, 1 week

5
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[PATCH v3 0/6] binder: Set up KUnit tests for alloc

by Tiffany Yang

Hello, binder_alloc_selftest provides a robust set of checks for the binder allocator, but it rarely runs because it must hook into a running binder process and block all other binder threads until it completes. The test itself is a good candidate for conversion to KUnit, and it can be further isolated from user processes by using a test-specific lru freelist instead of the global one. This series converts the selftest to KUnit to make it less burdensome to run and to set up a foundation for unit testing future binder_alloc changes. Thanks, Tiffany Tiffany Yang (6): binder: Fix selftest page indexing binder: Store lru freelist in binder_alloc kunit: test: Export kunit_attach_mm() binder: Scaffolding for binder_alloc KUnit tests binder: Convert binder_alloc selftests to KUnit binder: encapsulate individual alloc test cases drivers/android/Kconfig | 15 +- drivers/android/Makefile | 2 +- drivers/android/binder.c | 10 +- drivers/android/binder_alloc.c | 39 +- drivers/android/binder_alloc.h | 14 +- drivers/android/binder_alloc_selftest.c | 306 ----------- drivers/android/binder_internal.h | 4 + drivers/android/tests/.kunitconfig | 3 + drivers/android/tests/Makefile | 3 + drivers/android/tests/binder_alloc_kunit.c | 573 +++++++++++++++++++++ include/kunit/test.h | 12 + lib/kunit/user_alloc.c | 4 +- 12 files changed, 645 insertions(+), 340 deletions(-) delete mode 100644 drivers/android/binder_alloc_selftest.c create mode 100644 drivers/android/tests/.kunitconfig create mode 100644 drivers/android/tests/Makefile create mode 100644 drivers/android/tests/binder_alloc_kunit.c -- 2.50.0.727.gbf7dc18ff4-goog

5 months, 1 week

3
24
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[PATCH v7 0/7] use per-vma locks for /proc/pid/maps reads

by Suren Baghdasaryan

Reading /proc/pid/maps requires read-locking mmap_lock which prevents any other task from concurrently modifying the address space. This guarantees coherent reporting of virtual address ranges, however it can block important updates from happening. Oftentimes /proc/pid/maps readers are low priority monitoring tasks and them blocking high priority tasks results in priority inversion. Locking the entire address space is required to present fully coherent picture of the address space, however even current implementation does not strictly guarantee that by outputting vmas in page-size chunks and dropping mmap_lock in between each chunk. Address space modifications are possible while mmap_lock is dropped and userspace reading the content is expected to deal with possible concurrent address space modifications. Considering these relaxed rules, holding mmap_lock is not strictly needed as long as we can guarantee that a concurrently modified vma is reported either in its original form or after it was modified. This patchset switches from holding mmap_lock while reading /proc/pid/maps to taking per-vma locks as we walk the vma tree. This reduces the contention with tasks modifying the address space because they would have to contend for the same vma as opposed to the entire address space. Previous version of this patchset [1] tried to perform /proc/pid/maps reading under RCU, however its implementation is quite complex and the results are worse than the new version because it still relied on mmap_lock speculation which retries if any part of the address space gets modified. New implementaion is both simpler and results in less contention. Note that similar approach would not work for /proc/pid/smaps reading as it also walks the page table and that's not RCU-safe. Paul McKenney's designed a test [2] to measure mmap/munmap latencies while concurrently reading /proc/pid/maps. The test has a pair of processes scanning /proc/PID/maps, and another process unmapping and remapping 4K pages from a 128MB range of anonymous memory. At the end of each 10 second run, the latency of each mmap() or munmap() operation is measured, and for each run the maximum and mean latency is printed. The map/unmap process is started first, its PID is passed to the scanners, and then the map/unmap process waits until both scanners are running before starting its timed test. The scanners keep scanning until the specified /proc/PID/maps file disappears. The latest results from Paul: Stock mm-unstable, all of the runs had maximum latencies in excess of 0.5 milliseconds, and with 80% of the runs' latencies exceeding a full millisecond, and ranging up beyond 4 full milliseconds. In contrast, 99% of the runs with this patch series applied had maximum latencies of less than 0.5 milliseconds, with the single outlier at only 0.608 milliseconds. From a median-performance (as opposed to maximum-latency) viewpoint, this patch series also looks good, with stock mm weighing in at 11 microseconds and patch series at 6 microseconds, better than a 2x improvement. Before the change: ./run-proc-vs-map.sh --nsamples 100 --rawdata -- --busyduration 2 0.011 0.008 0.521 0.011 0.008 0.552 0.011 0.008 0.590 0.011 0.008 0.660 ... 0.011 0.015 2.987 0.011 0.015 3.038 0.011 0.016 3.431 0.011 0.016 4.707 After the change: ./run-proc-vs-map.sh --nsamples 100 --rawdata -- --busyduration 2 0.006 0.005 0.026 0.006 0.005 0.029 0.006 0.005 0.034 0.006 0.005 0.035 ... 0.006 0.006 0.421 0.006 0.006 0.423 0.006 0.006 0.439 0.006 0.006 0.608 The patchset also adds a number of tests to check for /proc/pid/maps data coherency. They are designed to detect any unexpected data tearing while performing some common address space modifications (vma split, resize and remap). Even before these changes, reading /proc/pid/maps might have inconsistent data because the file is read page-by-page with mmap_lock being dropped between the pages. An example of user-visible inconsistency can be that the same vma is printed twice: once before it was modified and then after the modifications. For example if vma was extended, it might be found and reported twice. What is not expected is to see a gap where there should have been a vma both before and after modification. This patchset increases the chances of such tearing, therefore it's even more important now to test for unexpected inconsistencies. In [3] Lorenzo identified the following possible vma merging/splitting scenarios: Merges with changes to existing vmas: 1 Merge both - mapping a vma over another one and between two vmas which can be merged after this replacement; 2. Merge left full - mapping a vma at the end of an existing one and completely over its right neighbor; 3. Merge left partial - mapping a vma at the end of an existing one and partially over its right neighbor; 4. Merge right full - mapping a vma before the start of an existing one and completely over its left neighbor; 5. Merge right partial - mapping a vma before the start of an existing one and partially over its left neighbor; Merges without changes to existing vmas: 6. Merge both - mapping a vma into a gap between two vmas which can be merged after the insertion; 7. Merge left - mapping a vma at the end of an existing one; 8. Merge right - mapping a vma before the start end of an existing one; Splits 9. Split with new vma at the lower address; 10. Split with new vma at the higher address; If such merges or splits happen concurrently with the /proc/maps reading we might report a vma twice, once before the modification and once after it is modified: Case 1 might report overwritten and previous vma along with the final merged vma; Case 2 might report previous and the final merged vma; Case 3 might cause us to retry once we detect the temporary gap caused by shrinking of the right neighbor; Case 4 might report overritten and the final merged vma; Case 5 might cause us to retry once we detect the temporary gap caused by shrinking of the left neighbor; Case 6 might report previous vma and the gap along with the final marged vma; Case 7 might report previous and the final merged vma; Case 8 might report the original gap and the final merged vma covering the gap; Case 9 might cause us to retry once we detect the temporary gap caused by shrinking of the original vma at the vma start; Case 10 might cause us to retry once we detect the temporary gap caused by shrinking of the original vma at the vma end; In all these cases the retry mechanism prevents us from reporting possible temporary gaps. Changes since v6 [4]: - Updated patch 7/8 changelog, per Lorenzo Stoakes - Added comments, per Lorenzo Stoakes - Added Reviewed-by, per Lorenzo Stoakes and Liam Howlett - Replaced iter with vmi, per Lorenzo Stoakes - Renamed from lock_vma_under_mmap_lock() to lock_next_vma_under_mmap_lock(), per Lorenzo Stoakes - Renamed lock_next_vma() parameter from addr to from_addr - Renamed labels in lock_next_vma() to reflect fallback cases, per Lorenzo Stoakes - Handle vma_start_read_locked() failure inside lock_next_vma_under_mmap_lock() and added fallback_to_mmap_lock() for that, per Vlastimil Babka - Added missing vma_iter_init() after re-entering rcu read section inside lock_next_vma(), per Vlastimil Babka - Replaced vma_iter_init() with vma_iter_set(), per Liam Howlett - Removed the last patch converting PROCMAP_QUERY to use per-vma locks. That patch will be posted separately, per David Hildenbrand, Vlastimil Babka and Liam Howlett - Updated performance numbers, per Paul E. McKenney !!! NOTES FOR APPLYING THE PATCHSET !!! Applies cleanly over mm-unstable after reverting v6 version of this patchset (from 2771a4b86aa1 to a20b00f7cf33 in mm-unstable). [1] https://lore.kernel.org/all/20250418174959.1431962-1-surenb@google.com/ [2] https://github.com/paulmckrcu/proc-mmap_sem-test [3] https://lore.kernel.org/all/e1863f40-39ab-4e5b-984a-c48765ffde1c@lucifer.lo… [4] https://lore.kernel.org/all/20250704060727.724817-1-surenb@google.com/ Suren Baghdasaryan (7): selftests/proc: add /proc/pid/maps tearing from vma split test selftests/proc: extend /proc/pid/maps tearing test to include vma resizing selftests/proc: extend /proc/pid/maps tearing test to include vma remapping selftests/proc: test PROCMAP_QUERY ioctl while vma is concurrently modified selftests/proc: add verbose more for tests to facilitate debugging fs/proc/task_mmu: remove conversion of seq_file position to unsigned fs/proc/task_mmu: read proc/pid/maps under per-vma lock fs/proc/internal.h | 5 + fs/proc/task_mmu.c | 155 +++- include/linux/mmap_lock.h | 11 + mm/madvise.c | 3 +- mm/mmap_lock.c | 93 ++ tools/testing/selftests/proc/.gitignore | 1 + tools/testing/selftests/proc/Makefile | 1 + tools/testing/selftests/proc/proc-maps-race.c | 829 ++++++++++++++++++ 8 files changed, 1082 insertions(+), 16 deletions(-) create mode 100644 tools/testing/selftests/proc/proc-maps-race.c -- 2.50.0.727.gbf7dc18ff4-goog

5 months, 1 week

5
19
0 0

[PATCH 0/2] bpf, arm64: relax constraint in BPF JIT compiler

by Alexis Lothoré (eBPF Foundation)

Hello, this series follows up on the one introducing 9+ args for tracing programs [1]. It has been observed with this series that there are cases for which we can not identify accurately the location of the target function arguments to prepare correctly the corresponding BPF trampoline. This is the case for example if: - the function consumes a struct variable _by value_ - it is passed on the stack (no more register available for it) - it has some __packed__ or __aligned(X)__ attribute As a consequence, a small restrictive check has been added to the ARM64 side, highlighting that other arch supporting 9+ args in BPF trampolines are already suffering from the same issue. After a bit of discussions and attempts, the chosen solution is, rather than applying the same constraint to all JIT compilers, to prevent such function from being encoded at all in BTF info([2]). As the pahole side is closed to be integrated, we can now remove the restrictive check from kernel side. [1] https://lore.kernel.org/bpf/20250527-many_args_arm64-v3-0-3faf7bb8e4a2@boot… [2] https://lore.kernel.org/bpf/20250707-btf_skip_structs_on_stack-v3-0-29569e0… Signed-off-by: Alexis Lothoré (eBPF Foundation) <alexis.lothore(a)bootlin.com> --- Alexis Lothoré (eBPF Foundation) (2): bpf, arm64: remove structs on stack constraint selftests/bpf: enable tracing_struct tests for arm64 arch/arm64/net/bpf_jit_comp.c | 5 ----- tools/testing/selftests/bpf/DENYLIST.aarch64 | 1 - 2 files changed, 6 deletions(-) --- base-commit: 8da1e37fc84868b50ba6a7cdf082aa3b0d11e006 change-id: 20250708-arm64_relax_jit_comp-e8889647d8d2 Best regards, -- Alexis Lothoré, Bootlin Embedded Linux and Kernel engineering https://bootlin.com

5 months, 1 week

5
8
0 0

[PATCH net-next v7 0/3] selftest: net: Add selftest for netpoll

by Breno Leitao

I am submitting a new selftest for the netpoll subsystem specifically targeting the case where the RX is polling in the TX path, which is a case that we don't have any test in the tree today. This is done when netpoll_poll_dev() called, and this test creates a scenario when that is probably. The test does the following: 1) Configuring a single RX/TX queue to increase contention on the interface. 2) Generating background traffic to saturate the network, mimicking real-world congestion. 3) Sending netconsole messages to trigger netpoll polling and monitor its behavior. 4) Using dynamic netconsole targets via configfs, with the ability to delete and recreate targets during the test. 5) Running bpftrace in parallel to verify that netpoll_poll_dev() is called when expected. If it is called, then the test passes, otherwise the test is marked as skipped. In order to achieve it, I stole Jakub's bpftrace helper from [1], and did some small changes that I found useful to use the helper. So, this patchset basically contains: 1) The code stolen from Jakub 2) Improvements on bpftrace() helper 3) The selftest itself Link: https://lore.kernel.org/all/20250421222827.283737-22-kuba@kernel.org/ [1] --- Changes in v7: - Rebased on top of net-next - Using `ethtool -l` json option instead of parsing it manually. - Link to v6: https://lore.kernel.org/r/20250711-netpoll_test-v6-0-130465f286a8@debian.org Changes in v6: - Remove the network toggled (Jakub) - Set ringsize and queue size (Jakub) - Some other general improvements (Jakub) - Link to v5: https://lore.kernel.org/r/20250709-netpoll_test-v5-0-b3737895affe@debian.org Changes in v5: - Rebased on top of net-next. - Calling bpftrace_stop using the defer helper. (Willem) - Link to v4: https://lore.kernel.org/r/20250702-netpoll_test-v4-0-cec227e85639@debian.org Changes in v4: - Make the test XFail if it doesn't hit the function we are looking for - Toggle the interface while the traffic is flowing. - Bumped the number of messages from 10 to 40 per iterations. * This is hitting ~15 times per run on my vng test. - Decreased the time from 15 seconds to 10 seconds, given that if it didn't hit the function in 10 seconds, 5 seconds extra will not help. - Link to v3: https://lore.kernel.org/r/20250627-netpoll_test-v3-0-575bd200c8a9@debian.org Changes in v3: - Make pylint happy (Simon) - Remove the unnecessary patch in bpftrace to raise an exception when it fails. (Jakub) - Improved the bpftrace code (Willem) - Stop sending messages if bpftrace is not alive anymore. - Link to v2: https://lore.kernel.org/r/20250625-netpoll_test-v2-0-47d27775222c@debian.org Changes in v2: - Stole Jakub's helper to run bpftrace - Removed the DEBUG option and moved logs to logging - Change the code to have a higher chance of calling netpoll_poll_dev(). In my current configuration, it is hitting multiple times during the test. - Save and restore TX/RX queue size (Jakub) - Link to v1: https://lore.kernel.org/r/20250620-netpoll_test-v1-1-5068832f72fc@debian.org --- Breno Leitao (2): selftests: drv-net: Strip '@' prefix from bpftrace map keys selftests: net: add netpoll basic functionality test Jakub Kicinski (1): selftests: drv-net: add helper/wrapper for bpftrace tools/testing/selftests/drivers/net/Makefile | 1 + .../selftests/drivers/net/lib/py/__init__.py | 4 +- .../testing/selftests/drivers/net/netpoll_basic.py | 396 +++++++++++++++++++++ tools/testing/selftests/net/lib/py/utils.py | 35 ++ 4 files changed, 434 insertions(+), 2 deletions(-) --- base-commit: b06c4311711c57c5e558bd29824b08f0a6e2a155 change-id: 20250612-netpoll_test-a1324d2057c8 Best regards, -- Breno Leitao <leitao(a)debian.org>

5 months, 1 week

2
4
0 0

[PATCH v2 4/4] selftests/rseq: Add test for mm_cid compaction

by Gabriele Monaco

A task in the kernel (task_mm_cid_work) runs somewhat periodically to compact the mm_cid for each process. Add a test to validate that it runs correctly and timely. The test spawns 1 thread pinned to each CPU, then each thread, including the main one, runs in short bursts for some time. During this period, the mm_cids should be spanning all numbers between 0 and nproc. At the end of this phase, a thread with high enough mm_cid (>= nproc/2) is selected to be the new leader, all other threads terminate. After some time, the only running thread should see 0 as mm_cid, if that doesn't happen, the compaction mechanism didn't work and the test fails. The test never fails if only 1 core is available, in which case, we cannot test anything as the only available mm_cid is 0. Acked-by: Shuah Khan <skhan(a)linuxfoundation.org> Signed-off-by: Gabriele Monaco <gmonaco(a)redhat.com> --- tools/testing/selftests/rseq/.gitignore | 1 + tools/testing/selftests/rseq/Makefile | 2 +- .../selftests/rseq/mm_cid_compaction_test.c | 204 ++++++++++++++++++ 3 files changed, 206 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/rseq/mm_cid_compaction_test.c diff --git a/tools/testing/selftests/rseq/.gitignore b/tools/testing/selftests/rseq/.gitignore index 0fda241fa62b0..b3920c59bf401 100644 --- a/tools/testing/selftests/rseq/.gitignore +++ b/tools/testing/selftests/rseq/.gitignore @@ -3,6 +3,7 @@ basic_percpu_ops_test basic_percpu_ops_mm_cid_test basic_test basic_rseq_op_test +mm_cid_compaction_test param_test param_test_benchmark param_test_compare_twice diff --git a/tools/testing/selftests/rseq/Makefile b/tools/testing/selftests/rseq/Makefile index 0d0a5fae59547..bc4d940f66d40 100644 --- a/tools/testing/selftests/rseq/Makefile +++ b/tools/testing/selftests/rseq/Makefile @@ -17,7 +17,7 @@ OVERRIDE_TARGETS = 1 TEST_GEN_PROGS = basic_test basic_percpu_ops_test basic_percpu_ops_mm_cid_test param_test \ param_test_benchmark param_test_compare_twice param_test_mm_cid \ param_test_mm_cid_benchmark param_test_mm_cid_compare_twice \ - syscall_errors_test + syscall_errors_test mm_cid_compaction_test TEST_GEN_PROGS_EXTENDED = librseq.so diff --git a/tools/testing/selftests/rseq/mm_cid_compaction_test.c b/tools/testing/selftests/rseq/mm_cid_compaction_test.c new file mode 100644 index 0000000000000..d13623625f5a9 --- /dev/null +++ b/tools/testing/selftests/rseq/mm_cid_compaction_test.c @@ -0,0 +1,204 @@ +// SPDX-License-Identifier: LGPL-2.1 +#define _GNU_SOURCE +#include <assert.h> +#include <pthread.h> +#include <sched.h> +#include <stdint.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <stddef.h> + +#include "../kselftest.h" +#include "rseq.h" + +#define VERBOSE 0 +#define printf_verbose(fmt, ...) \ + do { \ + if (VERBOSE) \ + printf(fmt, ##__VA_ARGS__); \ + } while (0) + +/* 50 ms */ +#define RUNNER_PERIOD 50000 +/* + * Number of runs before we terminate or get the token. + * The number is slowly increasing with the number of CPUs as the compaction + * process can take longer on larger systems. This is an arbitrary value. + */ +#define THREAD_RUNS (3 + args->num_cpus/8) + +/* + * Number of times we check that the mm_cid were compacted. + * Checks are repeated every RUNNER_PERIOD. + */ +#define MM_CID_COMPACT_TIMEOUT 10 + +struct thread_args { + int cpu; + int num_cpus; + pthread_mutex_t *token; + pthread_barrier_t *barrier; + pthread_t *tinfo; + struct thread_args *args_head; +}; + +static void __noreturn *thread_runner(void *arg) +{ + struct thread_args *args = arg; + int i, ret, curr_mm_cid; + cpu_set_t cpumask; + + CPU_ZERO(&cpumask); + CPU_SET(args->cpu, &cpumask); + ret = pthread_setaffinity_np(pthread_self(), sizeof(cpumask), &cpumask); + if (ret) { + errno = ret; + perror("Error: failed to set affinity"); + abort(); + } + pthread_barrier_wait(args->barrier); + + for (i = 0; i < THREAD_RUNS; i++) + usleep(RUNNER_PERIOD); + curr_mm_cid = rseq_current_mm_cid(); + /* + * We select one thread with high enough mm_cid to be the new leader. + * All other threads (including the main thread) will terminate. + * After some time, the mm_cid of the only remaining thread should + * converge to 0, if not, the test fails. + */ + if (curr_mm_cid >= args->num_cpus / 2 && + !pthread_mutex_trylock(args->token)) { + printf_verbose( + "cpu%d has mm_cid=%d and will be the new leader.\n", + sched_getcpu(), curr_mm_cid); + for (i = 0; i < args->num_cpus; i++) { + if (args->tinfo[i] == pthread_self()) + continue; + ret = pthread_join(args->tinfo[i], NULL); + if (ret) { + errno = ret; + perror("Error: failed to join thread"); + abort(); + } + } + pthread_barrier_destroy(args->barrier); + free(args->tinfo); + free(args->token); + free(args->barrier); + free(args->args_head); + + for (i = 0; i < MM_CID_COMPACT_TIMEOUT; i++) { + curr_mm_cid = rseq_current_mm_cid(); + printf_verbose("run %d: mm_cid=%d on cpu%d.\n", i, + curr_mm_cid, sched_getcpu()); + if (curr_mm_cid == 0) + exit(EXIT_SUCCESS); + usleep(RUNNER_PERIOD); + } + exit(EXIT_FAILURE); + } + printf_verbose("cpu%d has mm_cid=%d and is going to terminate.\n", + sched_getcpu(), curr_mm_cid); + pthread_exit(NULL); +} + +int test_mm_cid_compaction(void) +{ + cpu_set_t affinity; + int i, j, ret = 0, num_threads; + pthread_t *tinfo; + pthread_mutex_t *token; + pthread_barrier_t *barrier; + struct thread_args *args; + + sched_getaffinity(0, sizeof(affinity), &affinity); + num_threads = CPU_COUNT(&affinity); + tinfo = calloc(num_threads, sizeof(*tinfo)); + if (!tinfo) { + perror("Error: failed to allocate tinfo"); + return -1; + } + args = calloc(num_threads, sizeof(*args)); + if (!args) { + perror("Error: failed to allocate args"); + ret = -1; + goto out_free_tinfo; + } + token = malloc(sizeof(*token)); + if (!token) { + perror("Error: failed to allocate token"); + ret = -1; + goto out_free_args; + } + barrier = malloc(sizeof(*barrier)); + if (!barrier) { + perror("Error: failed to allocate barrier"); + ret = -1; + goto out_free_token; + } + if (num_threads == 1) { + fprintf(stderr, "Cannot test on a single cpu. " + "Skipping mm_cid_compaction test.\n"); + /* only skipping the test, this is not a failure */ + goto out_free_barrier; + } + pthread_mutex_init(token, NULL); + ret = pthread_barrier_init(barrier, NULL, num_threads); + if (ret) { + errno = ret; + perror("Error: failed to initialise barrier"); + goto out_free_barrier; + } + for (i = 0, j = 0; i < CPU_SETSIZE && j < num_threads; i++) { + if (!CPU_ISSET(i, &affinity)) + continue; + args[j].num_cpus = num_threads; + args[j].tinfo = tinfo; + args[j].token = token; + args[j].barrier = barrier; + args[j].cpu = i; + args[j].args_head = args; + if (!j) { + /* The first thread is the main one */ + tinfo[0] = pthread_self(); + ++j; + continue; + } + ret = pthread_create(&tinfo[j], NULL, thread_runner, &args[j]); + if (ret) { + errno = ret; + perror("Error: failed to create thread"); + abort(); + } + ++j; + } + printf_verbose("Started %d threads.\n", num_threads); + + /* Also main thread will terminate if it is not selected as leader */ + thread_runner(&args[0]); + + /* only reached in case of errors */ +out_free_barrier: + free(barrier); +out_free_token: + free(token); +out_free_args: + free(args); +out_free_tinfo: + free(tinfo); + + return ret; +} + +int main(int argc, char **argv) +{ + if (!rseq_mm_cid_available()) { + fprintf(stderr, "Error: rseq_mm_cid unavailable\n"); + return -1; + } + if (test_mm_cid_compaction()) + return -1; + return 0; +} -- 2.50.1

5 months, 1 week

1
0
0 0

[PATCH net-next V5 0/5] net: netdevsim: hook in XDP handling

by Mohsin Bashir

This patch series add tests to validate XDP native support for PASS, DROP, ABORT, and TX actions, as well as headroom and tailroom adjustment. For adjustment tests, validate support for both the extension and shrinking cases across various packet sizes and offset values. The pass criteria for head/tail adjustment tests require that at-least one adjustment value works for at-least one packet size. This ensure that the variability in maximum supported head/tail adjustment offset across different drivers is being incorporated. The results reported in this series are based on fbnic. However, the series is tested against multiple other drivers including netdevism. Note: The XDP support for fbnic will be added later. --- Change-log: V5: - Fix warning caused by rcu_dereference() in p1 - Fix checkpatch warnings with P3, P4, and P5 V4: https://lore.kernel.org/netdev/20250714210352.1115230-1-mohsin.bashr@gmail.… V3: https://lore.kernel.org/netdev/20250712002648.2385849-1-mohsin.bashr@gmail.… V2: https://lore.kernel.org/netdev/20250710184351.63797-1-mohsin.bashr@gmail.com V1: https://lore.kernel.org/netdev/20250709173707.3177206-1-mohsin.bashr@gmail.… Jakub Kicinski (1): net: netdevsim: hook in XDP handling Mohsin Bashir (4): selftests: drv-net: Test XDP_PASS/DROP support selftests: drv-net: Test XDP_TX support selftests: drv-net: Test tail-adjustment support selftests: drv-net: Test head-adjustment support drivers/net/netdevsim/netdev.c | 19 +- tools/testing/selftests/drivers/net/Makefile | 1 + tools/testing/selftests/drivers/net/xdp.py | 656 ++++++++++++++++++ .../selftests/net/lib/xdp_native.bpf.c | 540 ++++++++++++++ 4 files changed, 1215 insertions(+), 1 deletion(-) create mode 100755 tools/testing/selftests/drivers/net/xdp.py create mode 100644 tools/testing/selftests/net/lib/xdp_native.bpf.c -- 2.47.1

5 months, 1 week

2
6
0 0

[PATCH v6 0/8] use per-vma locks for /proc/pid/maps reads and PROCMAP_QUERY

by Suren Baghdasaryan

Reading /proc/pid/maps requires read-locking mmap_lock which prevents any other task from concurrently modifying the address space. This guarantees coherent reporting of virtual address ranges, however it can block important updates from happening. Oftentimes /proc/pid/maps readers are low priority monitoring tasks and them blocking high priority tasks results in priority inversion. Locking the entire address space is required to present fully coherent picture of the address space, however even current implementation does not strictly guarantee that by outputting vmas in page-size chunks and dropping mmap_lock in between each chunk. Address space modifications are possible while mmap_lock is dropped and userspace reading the content is expected to deal with possible concurrent address space modifications. Considering these relaxed rules, holding mmap_lock is not strictly needed as long as we can guarantee that a concurrently modified vma is reported either in its original form or after it was modified. This patchset switches from holding mmap_lock while reading /proc/pid/maps to taking per-vma locks as we walk the vma tree. This reduces the contention with tasks modifying the address space because they would have to contend for the same vma as opposed to the entire address space. Same is done for PROCMAP_QUERY ioctl which locks only the vma that fell into the requested range instead of the entire address space. Previous version of this patchset [1] tried to perform /proc/pid/maps reading under RCU, however its implementation is quite complex and the results are worse than the new version because it still relied on mmap_lock speculation which retries if any part of the address space gets modified. New implementaion is both simpler and results in less contention. Note that similar approach would not work for /proc/pid/smaps reading as it also walks the page table and that's not RCU-safe. Paul McKenney's designed a test [2] to measure mmap/munmap latencies while concurrently reading /proc/pid/maps. The test has a pair of processes scanning /proc/PID/maps, and another process unmapping and remapping 4K pages from a 128MB range of anonymous memory. At the end of each 10 second run, the latency of each mmap() or munmap() operation is measured, and for each run the maximum and mean latency is printed. The map/unmap process is started first, its PID is passed to the scanners, and then the map/unmap process waits until both scanners are running before starting its timed test. The scanners keep scanning until the specified /proc/PID/maps file disappears. This test registered close to 10x improvement in update latencies: Before the change: ./run-proc-vs-map.sh --nsamples 100 --rawdata -- --busyduration 2 0.011 0.008 0.455 0.011 0.008 0.472 0.011 0.008 0.535 0.011 0.009 0.545 ... 0.011 0.014 2.875 0.011 0.014 2.913 0.011 0.014 3.007 0.011 0.015 3.018 After the change: ./run-proc-vs-map.sh --nsamples 100 --rawdata -- --busyduration 2 0.006 0.005 0.036 0.006 0.005 0.039 0.006 0.005 0.039 0.006 0.005 0.039 ... 0.006 0.006 0.403 0.006 0.006 0.474 0.006 0.006 0.479 0.006 0.006 0.498 The patchset also adds a number of tests to check for /proc/pid/maps data coherency. They are designed to detect any unexpected data tearing while performing some common address space modifications (vma split, resize and remap). Even before these changes, reading /proc/pid/maps might have inconsistent data because the file is read page-by-page with mmap_lock being dropped between the pages. An example of user-visible inconsistency can be that the same vma is printed twice: once before it was modified and then after the modifications. For example if vma was extended, it might be found and reported twice. What is not expected is to see a gap where there should have been a vma both before and after modification. This patchset increases the chances of such tearing, therefore it's even more important now to test for unexpected inconsistencies. In [3] Lorenzo identified the following possible vma merging/splitting scenarios: Merges with changes to existing vmas: 1 Merge both - mapping a vma over another one and between two vmas which can be merged after this replacement; 2. Merge left full - mapping a vma at the end of an existing one and completely over its right neighbor; 3. Merge left partial - mapping a vma at the end of an existing one and partially over its right neighbor; 4. Merge right full - mapping a vma before the start of an existing one and completely over its left neighbor; 5. Merge right partial - mapping a vma before the start of an existing one and partially over its left neighbor; Merges without changes to existing vmas: 6. Merge both - mapping a vma into a gap between two vmas which can be merged after the insertion; 7. Merge left - mapping a vma at the end of an existing one; 8. Merge right - mapping a vma before the start end of an existing one; Splits 9. Split with new vma at the lower address; 10. Split with new vma at the higher address; If such merges or splits happen concurrently with the /proc/maps reading we might report a vma twice, once before the modification and once after it is modified: Case 1 might report overwritten and previous vma along with the final merged vma; Case 2 might report previous and the final merged vma; Case 3 might cause us to retry once we detect the temporary gap caused by shrinking of the right neighbor; Case 4 might report overritten and the final merged vma; Case 5 might cause us to retry once we detect the temporary gap caused by shrinking of the left neighbor; Case 6 might report previous vma and the gap along with the final marged vma; Case 7 might report previous and the final merged vma; Case 8 might report the original gap and the final merged vma covering the gap; Case 9 might cause us to retry once we detect the temporary gap caused by shrinking of the original vma at the vma start; Case 10 might cause us to retry once we detect the temporary gap caused by shrinking of the original vma at the vma end; In all these cases the retry mechanism prevents us from reporting possible temporary gaps. Changes since v5 [4]: - Made /proc/pid/maps tearing test a separate selftest, per Alexey Dobriyan - Changed asserts with or'ed conditions into separate ones, per Alexey Dobriyan - Added a small cleanup patch [6/8] to avoid unnecessary seq_file position type casting - Removed unnecessary is_sentinel_pos() helper - Changed titles to use fs/proc/task_mmu instead of mm/maps prefix, per David Hildenbrand - Included Lorenzo's fix for mmap lock assertion in anon_vma_name() - Reworked the last patch to avoid allocation in the rcu read section, which replaces Jeongjun Park's fix !!! NOTES FOR APPLYING THE PATCHSET !!! Applies cleanly over mm-unstable after reverting old version with fixes. The following patches should be reverted before applyng this patchset: b33ce1be8a40 ("selftests/proc: add /proc/pid/maps tearing from vma split test") b538e0580fd6 ("selftests/proc: extend /proc/pid/maps tearing test to include vma resizing") 4996b4409cc6 ("selftests/proc: extend /proc/pid/maps tearing test to include vma remapping") c39471f78d5e ("selftests/proc: test PROCMAP_QUERY ioctl while vma is concurrently modified") 487570f548f3 ("selftests/proc: add verbose more for tests to facilitate debugging") e1ba4969cba1 ("mm/maps: read proc/pid/maps under per-vma lock") ecb110179e77 ("mm/madvise: fixup stray mmap lock assert in anon_vma_name()") 6772c457a865 ("fs/proc/task_mmu:: execute PROCMAP_QUERY ioctl under per-vma locks") d5c67bb2c5fb ("mm/maps: move kmalloc() call location in do_procmap_query() out of RCU critical section") [1] https://lore.kernel.org/all/20250418174959.1431962-1-surenb@google.com/ [2] https://github.com/paulmckrcu/proc-mmap_sem-test [3] https://lore.kernel.org/all/e1863f40-39ab-4e5b-984a-c48765ffde1c@lucifer.lo… [4] https://lore.kernel.org/all/20250624193359.3865351-1-surenb@google.com/ Suren Baghdasaryan (8): selftests/proc: add /proc/pid/maps tearing from vma split test selftests/proc: extend /proc/pid/maps tearing test to include vma resizing selftests/proc: extend /proc/pid/maps tearing test to include vma remapping selftests/proc: test PROCMAP_QUERY ioctl while vma is concurrently modified selftests/proc: add verbose more for tests to facilitate debugging fs/proc/task_mmu: remove conversion of seq_file position to unsigned fs/proc/task_mmu: read proc/pid/maps under per-vma lock fs/proc/task_mmu: execute PROCMAP_QUERY ioctl under per-vma locks fs/proc/internal.h | 5 + fs/proc/task_mmu.c | 188 +++- include/linux/mmap_lock.h | 11 + mm/madvise.c | 3 +- mm/mmap_lock.c | 88 ++ tools/testing/selftests/proc/.gitignore | 1 + tools/testing/selftests/proc/Makefile | 1 + tools/testing/selftests/proc/proc-maps-race.c | 829 ++++++++++++++++++ 8 files changed, 1098 insertions(+), 28 deletions(-) create mode 100644 tools/testing/selftests/proc/proc-maps-race.c -- 2.50.0.727.gbf7dc18ff4-goog

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