October 2024 - Linux-kselftest-mirror

[PATCH v3 0/5] implement lightweight guard pages

by Lorenzo Stoakes

Userland library functions such as allocators and threading implementations often require regions of memory to act as 'guard pages' - mappings which, when accessed, result in a fatal signal being sent to the accessing process. The current means by which these are implemented is via a PROT_NONE mmap() mapping, which provides the required semantics however incur an overhead of a VMA for each such region. With a great many processes and threads, this can rapidly add up and incur a significant memory penalty. It also has the added problem of preventing merges that might otherwise be permitted. This series takes a different approach - an idea suggested by Vlasimil Babka (and before him David Hildenbrand and Jann Horn - perhaps more - the provenance becomes a little tricky to ascertain after this - please forgive any omissions!) - rather than locating the guard pages at the VMA layer, instead placing them in page tables mapping the required ranges. Early testing of the prototype version of this code suggests a 5 times speed up in memory mapping invocations (in conjunction with use of process_madvise()) and a 13% reduction in VMAs on an entirely idle android system and unoptimised code. We expect with optimisation and a loaded system with a larger number of guard pages this could significantly increase, but in any case these numbers are encouraging. This way, rather than having separate VMAs specifying which parts of a range are guard pages, instead we have a VMA spanning the entire range of memory a user is permitted to access and including ranges which are to be 'guarded'. After mapping this, a user can specify which parts of the range should result in a fatal signal when accessed. By restricting the ability to specify guard pages to memory mapped by existing VMAs, we can rely on the mappings being torn down when the mappings are ultimately unmapped and everything works simply as if the memory were not faulted in, from the point of view of the containing VMAs. This mechanism in effect poisons memory ranges similar to hardware memory poisoning, only it is an entirely software-controlled form of poisoning. The mechanism is implemented via madvise() behaviour - MADV_GUARD_INSTALL which installs page table-level guard page markers - and MADV_GUARD_REMOVE - which clears them. Guard markers can be installed across multiple VMAs and any existing mappings will be cleared, that is zapped, before installing the guard page markers in the page tables. There is no concept of 'nested' guard markers, multiple attempts to install guard markers in a range will, after the first attempt, have no effect. Importantly, removing guard markers over a range that contains both guard markers and ordinary backed memory has no effect on anything but the guard markers (including leaving huge pages un-split), so a user can safely remove guard markers over a range of memory leaving the rest intact. The actual mechanism by which the page table entries are specified makes use of existing logic - PTE markers, which are used for the userfaultfd UFFDIO_POISON mechanism. Unfortunately PTE_MARKER_POISONED is not suited for the guard page mechanism as it results in VM_FAULT_HWPOISON semantics in the fault handler, so we add our own specific PTE_MARKER_GUARD and adapt existing logic to handle it. We also extend the generic page walk mechanism to allow for installation of PTEs (carefully restricted to memory management logic only to prevent unwanted abuse). We ensure that zapping performed by MADV_DONTNEED and MADV_FREE do not remove guard markers, nor does forking (except when VM_WIPEONFORK is specified for a VMA which implies a total removal of memory characteristics). It's important to note that the guard page implementation is emphatically NOT a security feature, so a user can remove the markers if they wish. We simply implement it in such a way as to provide the least surprising behaviour. An extensive set of self-tests are provided which ensure behaviour is as expected and additionally self-documents expected behaviour of guard ranges. Suggested-by: Vlastimil Babka <vbabka(a)suse.cz> Suggested-by: Jann Horn <jannh(a)google.com> Suggested-by: David Hildenbrand <david(a)redhat.com> v3 * Cleaned up mm/pagewalk.c logic a bit to make things clearer, as suggested by Vlastiml. * Explicitly avoid splitting THP on PTE installation, as suggested by Vlastimil. Note this has no impact on the guard pages logic, which has page table entry handlers at PUD, PMD and PTE level. * Added WARN_ON_ONCE() to mm/hugetlb.c path where we don't expect a guard marker, as suggested by Vlastimil. * Reverted change to is_poisoned_swp_entry() to exclude guard pages which has the effect of MADV_FREE _not_ clearing guard pages. After discussion with Vlastimil, it became apparent that the ability to 'cancel' the freeing operation by writing to the mapping after having issued an MADV_FREE would mean that we would risk unexpected behaviour should the guard pages be removed, so we now do not remove markers here at all. * Added comment to PTE_MARKER_GUARD to highlight that memory tagged with the marker behaves as if it were a region mapped PROT_NONE, as highlighted by David. * Rename poison -> install, unpoison -> remove (i.e. MADV_GUARD_INSTALL / MADV_GUARD_REMOVE over MADV_GUARD_POISON / MADV_GUARD_REMOVE) at the request of David and John who both find the poison analogy confusing/overloaded. * After a lot of discussion, replace the looping behaviour should page faults race with guard page installation with a modest reattempt followed by returning -ERESTARTNOINTR to have the operation abort and re-enter, relieving lock contention and avoiding the possibility of allowing a malicious sandboxed process to impact the mmap lock or stall the overall process more than necessary, as suggested by Jann and Vlastimil having raised the issue. * Adjusted the page table walker so a populated huge PUD or PMD is correctly treated as being populated, necessitating a zap. In v2 we incorrectly skipped over these, which would cause the logic to wrongly proceed as if nothing were populated and the install succeeded. Instead, explicitly check to see if a huge page - if so, do not split but rather abort the operation and let zap take care of things. * Updated the guard remove logic to not unnecessarily split huge pages either. * Added a debug check to assert that the number of installed PTEs matches expectation, accounting for any existing guard pages. * Adapted vector_madvise() used by the process_madvise() system call to handle -ERESTARTNOINTR correctly. v2 * The macros in kselftest_harness.h seem to be broken - __EXPECT() is terminated by '} while (0); OPTIONAL_HANDLER(_assert)' meaning it is not safe in single line if / else or for /which blocks, however working around this results in checkpatch producing invalid warnings, as reported by Shuah. * Fixing these macros is out of scope for this series, so compromise and instead rewrite test blocks so as to use multiple lines by separating out a decl in most cases. This has the side effect of, for the most part, making things more readable. * Heavily document the use of the volatile keyword - we can't avoid checkpatch complaining about this, so we explain it, as reported by Shuah. * Updated commit message to highlight that we skip tests we lack permissions for, as reported by Shuah. * Replaced a perror() with ksft_exit_fail_perror(), as reported by Shuah. * Added user friendly messages to cases where tests are skipped due to lack of permissions, as reported by Shuah. * Update the tool header to include the new MADV_GUARD_POISON/UNPOISON defines and directly include asm-generic/mman.h to get the platform-neutral versions to ensure we import them. * Finally fixed Vlastimil's email address in Suggested-by tags from suze to suse, as reported by Vlastimil. * Added linux-api to cc list, as reported by Vlastimil. https://lore.kernel.org/all/cover.1729440856.git.lorenzo.stoakes@oracle.com/ v1 * Un-RFC'd as appears no major objections to approach but rather debate on implementation. * Fixed issue with arches which need mmu_context.h and tlbfush.h. header imports in pagewalker logic to be able to use update_mmu_cache() as reported by the kernel test bot. * Added comments in page walker logic to clarify who can use ops->install_pte and why as well as adding a check_ops_valid() helper function, as suggested by Christoph. * Pass false in full parameter in pte_clear_not_present_full() as suggested by Jann. * Stopped erroneously requiring a write lock for the poison operation as suggested by Jann and Suren. * Moved anon_vma_prepare() to the start of madvise_guard_poison() to be consistent with how this is used elsewhere in the kernel as suggested by Jann. * Avoid returning -EAGAIN if we are raced on page faults, just keep looping and duck out if a fatal signal is pending or a conditional reschedule is needed, as suggested by Jann. * Avoid needlessly splitting huge PUDs and PMDs by specifying ACTION_CONTINUE, as suggested by Jann. https://lore.kernel.org/all/cover.1729196871.git.lorenzo.stoakes@oracle.com/ RFC https://lore.kernel.org/all/cover.1727440966.git.lorenzo.stoakes@oracle.com/ Lorenzo Stoakes (5): mm: pagewalk: add the ability to install PTEs mm: add PTE_MARKER_GUARD PTE marker mm: madvise: implement lightweight guard page mechanism tools: testing: update tools UAPI header for mman-common.h selftests/mm: add self tests for guard page feature arch/alpha/include/uapi/asm/mman.h | 3 + arch/mips/include/uapi/asm/mman.h | 3 + arch/parisc/include/uapi/asm/mman.h | 3 + arch/xtensa/include/uapi/asm/mman.h | 3 + include/linux/mm_inline.h | 2 +- include/linux/pagewalk.h | 18 +- include/linux/swapops.h | 24 +- include/uapi/asm-generic/mman-common.h | 3 + mm/hugetlb.c | 4 + mm/internal.h | 12 + mm/madvise.c | 225 ++++ mm/memory.c | 18 +- mm/mprotect.c | 6 +- mm/mseal.c | 1 + mm/pagewalk.c | 227 +++- tools/include/uapi/asm-generic/mman-common.h | 3 + tools/testing/selftests/mm/.gitignore | 1 + tools/testing/selftests/mm/Makefile | 1 + tools/testing/selftests/mm/guard-pages.c | 1239 ++++++++++++++++++ 19 files changed, 1720 insertions(+), 76 deletions(-) create mode 100644 tools/testing/selftests/mm/guard-pages.c -- 2.47.0

10 months

5
28
0 0

kselftest:arm64/FVP: arm64_check_buffer_fill - failed on Linux next-20241025

by Naresh Kamboju

The following kselftest arm64 and FVP failed with Linux next-20241025 on - Qemu-arm64 - FVP running Linux next-20241025 kernel. First seen on next-20241025 Good: next-20241024 BAD: next-20241025 kselftest-arm64, FVP * arm64_check_buffer_fill * arm64_check_mmap_options * arm64_check_child_memory Anyone have seen these failures ? Reported-by: Linux Kernel Functional Testing <lkft(a)linaro.org> Test log: ---------- # selftests: arm64: check_buffer_fill # 1..20 # ok 1 Check buffer correctness by byte with sync err mode and mmap memory # ok 2 Check buffer correctness by byte with async err mode and mmap memory # ok 3 Check buffer correctness by byte with sync err mode and mmap/mprotect memory # ok 4 Check buffer correctness by byte with async err mode and mmap/mprotect memory # ok 5 Check buffer write underflow by byte with sync mode and mmap memory # ok 6 Check buffer write underflow by byte with async mode and mmap memory # ok 7 Check buffer write underflow by byte with tag check fault ignore and mmap memory # ok 8 Check buffer write underflow by byte with sync mode and mmap memory # ok 9 Check buffer write underflow by byte with async mode and mmap memory # ok 10 Check buffer write underflow by byte with tag check fault ignore and mmap memory # ok 11 Check buffer write overflow by byte with sync mode and mmap memory # ok 12 Check buffer write overflow by byte with async mode and mmap memory # ok 13 Check buffer write overflow by byte with tag fault ignore mode and mmap memory # ok 14 Check buffer write correctness by block with sync mode and mmap memory # ok 15 Check buffer write correctness by block with async mode and mmap memory # ok 16 Check buffer write correctness by block with tag fault ignore and mmap memory # # FAIL: mmap allocation # # FAIL: memory allocation # not ok 17 Check initial tags with private mapping, sync error mode and mmap memory # ok 18 Check initial tags with private mapping, sync error mode and mmap/mprotect memory # # FAIL: mmap allocation # # FAIL: memory allocation # not ok 19 Check initial tags with shared mapping, sync error mode and mmap memory # ok 20 Check initial tags with shared mapping, sync error mode and mmap/mprotect memory # # Totals: pass:18 fail:2 xfail:0 xpass:0 skip:0 error:0 not ok 21 selftests: arm64: check_buffer_fill # exit=1 # timeout set to 45 # selftests: arm64: check_child_memory # 1..12 # ok 1 Check child anonymous memory with private mapping, precise mode and mmap memory # ok 2 Check child anonymous memory with shared mapping, precise mode and mmap memory # ok 3 Check child anonymous memory with private mapping, imprecise mode and mmap memory # ok 4 Check child anonymous memory with shared mapping, imprecise mode and mmap memory # ok 5 Check child anonymous memory with private mapping, precise mode and mmap/mprotect memory # ok 6 Check child anonymous memory with shared mapping, precise mode and mmap/mprotect memory # # FAIL: mmap allocation # # FAIL: memory allocation # not ok 7 Check child file memory with private mapping, precise mode and mmap memory # # FAIL: mmap allocation # # FAIL: memory allocation # not ok 8 Check child file memory with shared mapping, precise mode and mmap memory # ok 9 Check child file memory with private mapping, imprecise mode and mmap memory # ok 10 Check child file memory with shared mapping, imprecise mode and mmap memory # ok 11 Check child file memory with private mapping, precise mode and mmap/mprotect memory # ok 12 Check child file memory with shared mapping, precise mode and mmap/mprotect memory # # Totals: pass:10 fail:2 xfail:0 xpass:0 skip:0 error:0 not ok 22 selftests: arm64: check_child_memory # exit=1 boot Log links, -------- - https://qa-reports.linaro.org/lkft/linux-next-master/build/next-20241028/te… - https://qa-reports.linaro.org/lkft/linux-next-master/build/next-20241028/te… Test results history: ---------- - https://qa-reports.linaro.org/lkft/linux-next-master/build/next-20241028/te… - https://qa-reports.linaro.org/lkft/linux-next-master/build/next-20241028/te… metadata: ---- git describe: next-20241028 git repo: https://gitlab.com/Linaro/lkft/mirrors/next/linux-next git sha: dec9255a128e19c5fcc3bdb18175d78094cc624d kernel config: https://storage.tuxsuite.com/public/linaro/lkft/builds/2o3tMqzOtHXYQjlvfR5t… build url: https://storage.tuxsuite.com/public/linaro/lkft/builds/2o3tMqzOtHXYQjlvfR5t… toolchain: gcc-13 Steps to reproduce: --------- - https://tuxapi.tuxsuite.com/v1/groups/linaro/projects/lkft/tests/2o3tON5kNi… - https://tuxapi.tuxsuite.com/v1/groups/linaro/projects/lkft/tests/2o3tON5kNi… -- Linaro LKFT https://lkft.linaro.org

10 months

2
1
0 0

[PATCH v1 00/10] iommufd: Add VIOMMU infrastructure (Part-2 VIRQ)

by Nicolin Chen

As the part-2 of the VIOMMU infrastructure, this series introduces a VIRQ object after repurposing the existing FAULT object, which provides a nice notification pathway to the user space already. So, the first thing to do is reworking the FAULT object. Mimicing the HWPT structures, add a common EVENT structure to support its derivatives: EVENT_IOPF (the prior FAULT object) and EVENT_VIRQ (new one). IOMMUFD_CMD_VIRQ_ALLOC is introduced to allocate EVENT_VIRQ for a VIOMMU. One VIOMMU can have multiple VIRQs in different types but can not support multiple VIRQs with the same types. Drivers might need the VIOMMU's vdev_id list or the exact vdev_id link of the passthrough device's to forward IRQs/events via the VIOMMU framework. Thus, extend the set/unset_vdev_id ioctls down to the driver using VIOMMU ops. This allows drivers to take the control of a vdev_id's lifecycle. The forwarding part is fairly simple but might need to replace a physical device ID with a virtual device ID. So, there comes with some helpers for drivers to use. As usual, this series comes with the selftest coverage for this new VIRQ, and with a real world use case in the ARM SMMUv3 driver. This must be based on the VIOMMU Part-1 series. It's on Github: https://github.com/nicolinc/iommufd/commits/iommufd_virq-v1 Paring QEMU branch for testing: https://github.com/nicolinc/qemu/commits/wip/for_iommufd_virq-v1 Thanks! Nicolin Nicolin Chen (10): iommufd: Rename IOMMUFD_OBJ_FAULT to IOMMUFD_OBJ_EVENT_IOPF iommufd: Rename fault.c to event.c iommufd: Add IOMMUFD_OBJ_EVENT_VIRQ and IOMMUFD_CMD_VIRQ_ALLOC iommufd/viommu: Allow drivers to control vdev_id lifecycle iommufd/viommu: Add iommufd_vdev_id_to_dev helper iommufd/viommu: Add iommufd_viommu_report_irq helper iommufd/selftest: Implement mock_viommu_set/unset_vdev_id iommufd/selftest: Add IOMMU_TEST_OP_TRIGGER_VIRQ for VIRQ coverage iommufd/selftest: Add EVENT_VIRQ test coverage iommu/arm-smmu-v3: Report virtual IRQ for device in user space drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 109 +++- drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 2 + drivers/iommu/iommufd/Makefile | 2 +- drivers/iommu/iommufd/device.c | 2 + drivers/iommu/iommufd/event.c | 613 ++++++++++++++++++ drivers/iommu/iommufd/fault.c | 443 ------------- drivers/iommu/iommufd/hw_pagetable.c | 12 +- drivers/iommu/iommufd/iommufd_private.h | 147 ++++- drivers/iommu/iommufd/iommufd_test.h | 10 + drivers/iommu/iommufd/main.c | 13 +- drivers/iommu/iommufd/selftest.c | 66 ++ drivers/iommu/iommufd/viommu.c | 25 +- drivers/iommu/iommufd/viommu_api.c | 54 ++ include/linux/iommufd.h | 28 + include/uapi/linux/iommufd.h | 46 ++ tools/testing/selftests/iommu/iommufd.c | 11 + tools/testing/selftests/iommu/iommufd_utils.h | 64 ++ 17 files changed, 1130 insertions(+), 517 deletions(-) create mode 100644 drivers/iommu/iommufd/event.c delete mode 100644 drivers/iommu/iommufd/fault.c -- 2.43.0

10 months

2
16
0 0

[PATCH RFC 08/10] mm: page_frag: add testing for the newly added API

by Yunsheng Lin

Add testing for the newly added prepare API, for both aligned and non-aligned API, also probe API is also tested along with prepare API. CC: Alexander Duyck <alexander.duyck(a)gmail.com> CC: Andrew Morton <akpm(a)linux-foundation.org> CC: Linux-MM <linux-mm(a)kvack.org> Signed-off-by: Yunsheng Lin <linyunsheng(a)huawei.com> --- .../selftests/mm/page_frag/page_frag_test.c | 76 +++++++++++++++++-- tools/testing/selftests/mm/run_vmtests.sh | 4 + tools/testing/selftests/mm/test_page_frag.sh | 27 +++++++ 3 files changed, 102 insertions(+), 5 deletions(-) diff --git a/tools/testing/selftests/mm/page_frag/page_frag_test.c b/tools/testing/selftests/mm/page_frag/page_frag_test.c index e806c1866e36..3b3c32389def 100644 --- a/tools/testing/selftests/mm/page_frag/page_frag_test.c +++ b/tools/testing/selftests/mm/page_frag/page_frag_test.c @@ -32,6 +32,10 @@ static bool test_align; module_param(test_align, bool, 0); MODULE_PARM_DESC(test_align, "use align API for testing"); +static bool test_prepare; +module_param(test_prepare, bool, 0); +MODULE_PARM_DESC(test_prepare, "use prepare API for testing"); + static int test_alloc_len = 2048; module_param(test_alloc_len, int, 0); MODULE_PARM_DESC(test_alloc_len, "alloc len for testing"); @@ -74,6 +78,21 @@ static int page_frag_pop_thread(void *arg) return 0; } +static void frag_frag_test_commit(struct page_frag_cache *nc, + struct page_frag *prepare_pfrag, + struct page_frag *probe_pfrag, + unsigned int used_sz) +{ + if (prepare_pfrag->page != probe_pfrag->page || + prepare_pfrag->offset != probe_pfrag->offset || + prepare_pfrag->size != probe_pfrag->size) { + force_exit = true; + WARN_ONCE(true, TEST_FAILED_PREFIX "wrong probed info\n"); + } + + page_frag_refill_commit(nc, prepare_pfrag, used_sz); +} + static int page_frag_push_thread(void *arg) { struct ptr_ring *ring = arg; @@ -86,15 +105,61 @@ static int page_frag_push_thread(void *arg) int ret; if (test_align) { - va = page_frag_alloc_align(&test_nc, test_alloc_len, - GFP_KERNEL, SMP_CACHE_BYTES); + if (test_prepare) { + struct page_frag prepare_frag, probe_frag; + void *probe_va; + + va = page_frag_alloc_refill_prepare_align(&test_nc, + test_alloc_len, + &prepare_frag, + GFP_KERNEL, + SMP_CACHE_BYTES); + + probe_va = __page_frag_alloc_refill_probe_align(&test_nc, + test_alloc_len, + &probe_frag, + -SMP_CACHE_BYTES); + if (va != probe_va) { + force_exit = true; + WARN_ONCE(true, TEST_FAILED_PREFIX "wrong va\n"); + } + + if (likely(va)) + frag_frag_test_commit(&test_nc, &prepare_frag, + &probe_frag, test_alloc_len); + } else { + va = page_frag_alloc_align(&test_nc, + test_alloc_len, + GFP_KERNEL, + SMP_CACHE_BYTES); + } if ((unsigned long)va & (SMP_CACHE_BYTES - 1)) { force_exit = true; WARN_ONCE(true, TEST_FAILED_PREFIX "unaligned va returned\n"); } } else { - va = page_frag_alloc(&test_nc, test_alloc_len, GFP_KERNEL); + if (test_prepare) { + struct page_frag prepare_frag, probe_frag; + void *probe_va; + + va = page_frag_alloc_refill_prepare(&test_nc, test_alloc_len, + &prepare_frag, GFP_KERNEL); + + probe_va = page_frag_alloc_refill_probe(&test_nc, test_alloc_len, + &probe_frag); + + if (va != probe_va) { + force_exit = true; + WARN_ONCE(true, TEST_FAILED_PREFIX "wrong va\n"); + } + + if (likely(va)) + frag_frag_test_commit(&test_nc, &prepare_frag, + &probe_frag, test_alloc_len); + } else { + va = page_frag_alloc(&test_nc, test_alloc_len, GFP_KERNEL); + } } if (!va) @@ -176,8 +241,9 @@ static int __init page_frag_test_init(void) } duration = (u64)ktime_us_delta(ktime_get(), start); - pr_info("%d of iterations for %s testing took: %lluus\n", nr_test, - test_align ? "aligned" : "non-aligned", duration); + pr_info("%d of iterations for %s %s API testing took: %lluus\n", nr_test, + test_align ? "aligned" : "non-aligned", + test_prepare ? "prepare" : "alloc", duration); out: ptr_ring_cleanup(&ptr_ring, NULL); diff --git a/tools/testing/selftests/mm/run_vmtests.sh b/tools/testing/selftests/mm/run_vmtests.sh index 2c5394584af4..f6ff9080a6f2 100755 --- a/tools/testing/selftests/mm/run_vmtests.sh +++ b/tools/testing/selftests/mm/run_vmtests.sh @@ -464,6 +464,10 @@ CATEGORY="page_frag" run_test ./test_page_frag.sh aligned CATEGORY="page_frag" run_test ./test_page_frag.sh nonaligned +CATEGORY="page_frag" run_test ./test_page_frag.sh aligned_prepare + +CATEGORY="page_frag" run_test ./test_page_frag.sh nonaligned_prepare + echo "SUMMARY: PASS=${count_pass} SKIP=${count_skip} FAIL=${count_fail}" | tap_prefix echo "1..${count_total}" | tap_output diff --git a/tools/testing/selftests/mm/test_page_frag.sh b/tools/testing/selftests/mm/test_page_frag.sh index f55b105084cf..1c757fd11844 100755 --- a/tools/testing/selftests/mm/test_page_frag.sh +++ b/tools/testing/selftests/mm/test_page_frag.sh @@ -43,6 +43,8 @@ check_test_failed_prefix() { SMOKE_PARAM="test_push_cpu=$TEST_CPU_0 test_pop_cpu=$TEST_CPU_1" NONALIGNED_PARAM="$SMOKE_PARAM test_alloc_len=75 nr_test=$NR_TEST" ALIGNED_PARAM="$NONALIGNED_PARAM test_align=1" +NONALIGNED_PREPARE_PARAM="$NONALIGNED_PARAM test_prepare=1" +ALIGNED_PREPARE_PARAM="$ALIGNED_PARAM test_prepare=1" check_test_requirements() { @@ -77,6 +79,20 @@ run_aligned_check() insmod $DRIVER $ALIGNED_PARAM > /dev/null 2>&1 } +run_nonaligned_prepare_check() +{ + echo "Run performance tests to evaluate how fast nonaligned prepare API is." + + insmod $DRIVER $NONALIGNED_PREPARE_PARAM > /dev/null 2>&1 +} + +run_aligned_prepare_check() +{ + echo "Run performance tests to evaluate how fast aligned prepare API is." + + insmod $DRIVER $ALIGNED_PREPARE_PARAM > /dev/null 2>&1 +} + run_smoke_check() { echo "Run smoke test." @@ -87,6 +103,7 @@ run_smoke_check() usage() { echo -n "Usage: $0 [ aligned ] | [ nonaligned ] | | [ smoke ] | " + echo "[ aligned_prepare ] | [ nonaligned_prepare ] | " echo "manual parameters" echo echo "Valid tests and parameters:" @@ -107,6 +124,12 @@ usage() echo "# Performance testing for aligned alloc API" echo "$0 aligned" echo + echo "# Performance testing for nonaligned prepare API" + echo "$0 nonaligned_prepare" + echo + echo "# Performance testing for aligned prepare API" + echo "$0 aligned_prepare" + echo exit 0 } @@ -158,6 +181,10 @@ function run_test() run_nonaligned_check elif [[ "$1" = "aligned" ]]; then run_aligned_check + elif [[ "$1" = "nonaligned_prepare" ]]; then + run_nonaligned_prepare_check + elif [[ "$1" = "aligned_prepare" ]]; then + run_aligned_prepare_check else run_manual_check $@ fi -- 2.33.0

10 months

1
0
0 0

[PATCH net-next v23 4/7] mm: page_frag: avoid caller accessing 'page_frag_cache' directly

by Yunsheng Lin

Use appropriate frag_page API instead of caller accessing 'page_frag_cache' directly. CC: Alexander Duyck <alexander.duyck(a)gmail.com> CC: Andrew Morton <akpm(a)linux-foundation.org> CC: Linux-MM <linux-mm(a)kvack.org> Signed-off-by: Yunsheng Lin <linyunsheng(a)huawei.com> Reviewed-by: Alexander Duyck <alexanderduyck(a)fb.com> Acked-by: Chuck Lever <chuck.lever(a)oracle.com> --- drivers/vhost/net.c | 2 +- include/linux/page_frag_cache.h | 10 ++++++++++ net/core/skbuff.c | 6 +++--- net/rxrpc/conn_object.c | 4 +--- net/rxrpc/local_object.c | 4 +--- net/sunrpc/svcsock.c | 6 ++---- tools/testing/selftests/mm/page_frag/page_frag_test.c | 2 +- 7 files changed, 19 insertions(+), 15 deletions(-) diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c index f16279351db5..9ad37c012189 100644 --- a/drivers/vhost/net.c +++ b/drivers/vhost/net.c @@ -1325,7 +1325,7 @@ static int vhost_net_open(struct inode *inode, struct file *f) vqs[VHOST_NET_VQ_RX]); f->private_data = n; - n->pf_cache.va = NULL; + page_frag_cache_init(&n->pf_cache); return 0; } diff --git a/include/linux/page_frag_cache.h b/include/linux/page_frag_cache.h index 67ac8626ed9b..0a52f7a179c8 100644 --- a/include/linux/page_frag_cache.h +++ b/include/linux/page_frag_cache.h @@ -7,6 +7,16 @@ #include <linux/mm_types_task.h> #include <linux/types.h> +static inline void page_frag_cache_init(struct page_frag_cache *nc) +{ + nc->va = NULL; +} + +static inline bool page_frag_cache_is_pfmemalloc(struct page_frag_cache *nc) +{ + return !!nc->pfmemalloc; +} + void page_frag_cache_drain(struct page_frag_cache *nc); void __page_frag_cache_drain(struct page *page, unsigned int count); void *__page_frag_alloc_align(struct page_frag_cache *nc, unsigned int fragsz, diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 00afeb90c23a..6841e61a6bd0 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -753,14 +753,14 @@ struct sk_buff *__netdev_alloc_skb(struct net_device *dev, unsigned int len, if (in_hardirq() || irqs_disabled()) { nc = this_cpu_ptr(&netdev_alloc_cache); data = page_frag_alloc(nc, len, gfp_mask); - pfmemalloc = nc->pfmemalloc; + pfmemalloc = page_frag_cache_is_pfmemalloc(nc); } else { local_bh_disable(); local_lock_nested_bh(&napi_alloc_cache.bh_lock); nc = this_cpu_ptr(&napi_alloc_cache.page); data = page_frag_alloc(nc, len, gfp_mask); - pfmemalloc = nc->pfmemalloc; + pfmemalloc = page_frag_cache_is_pfmemalloc(nc); local_unlock_nested_bh(&napi_alloc_cache.bh_lock); local_bh_enable(); @@ -850,7 +850,7 @@ struct sk_buff *napi_alloc_skb(struct napi_struct *napi, unsigned int len) len = SKB_HEAD_ALIGN(len); data = page_frag_alloc(&nc->page, len, gfp_mask); - pfmemalloc = nc->page.pfmemalloc; + pfmemalloc = page_frag_cache_is_pfmemalloc(&nc->page); } local_unlock_nested_bh(&napi_alloc_cache.bh_lock); diff --git a/net/rxrpc/conn_object.c b/net/rxrpc/conn_object.c index 1539d315afe7..694c4df7a1a3 100644 --- a/net/rxrpc/conn_object.c +++ b/net/rxrpc/conn_object.c @@ -337,9 +337,7 @@ static void rxrpc_clean_up_connection(struct work_struct *work) */ rxrpc_purge_queue(&conn->rx_queue); - if (conn->tx_data_alloc.va) - __page_frag_cache_drain(virt_to_page(conn->tx_data_alloc.va), - conn->tx_data_alloc.pagecnt_bias); + page_frag_cache_drain(&conn->tx_data_alloc); call_rcu(&conn->rcu, rxrpc_rcu_free_connection); } diff --git a/net/rxrpc/local_object.c b/net/rxrpc/local_object.c index f9623ace2201..2792d2304605 100644 --- a/net/rxrpc/local_object.c +++ b/net/rxrpc/local_object.c @@ -452,9 +452,7 @@ void rxrpc_destroy_local(struct rxrpc_local *local) #endif rxrpc_purge_queue(&local->rx_queue); rxrpc_purge_client_connections(local); - if (local->tx_alloc.va) - __page_frag_cache_drain(virt_to_page(local->tx_alloc.va), - local->tx_alloc.pagecnt_bias); + page_frag_cache_drain(&local->tx_alloc); } /* diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c index 825ec5357691..b785425c3315 100644 --- a/net/sunrpc/svcsock.c +++ b/net/sunrpc/svcsock.c @@ -1608,7 +1608,6 @@ static void svc_tcp_sock_detach(struct svc_xprt *xprt) static void svc_sock_free(struct svc_xprt *xprt) { struct svc_sock *svsk = container_of(xprt, struct svc_sock, sk_xprt); - struct page_frag_cache *pfc = &svsk->sk_frag_cache; struct socket *sock = svsk->sk_sock; trace_svcsock_free(svsk, sock); @@ -1618,8 +1617,7 @@ static void svc_sock_free(struct svc_xprt *xprt) sockfd_put(sock); else sock_release(sock); - if (pfc->va) - __page_frag_cache_drain(virt_to_head_page(pfc->va), - pfc->pagecnt_bias); + + page_frag_cache_drain(&svsk->sk_frag_cache); kfree(svsk); } diff --git a/tools/testing/selftests/mm/page_frag/page_frag_test.c b/tools/testing/selftests/mm/page_frag/page_frag_test.c index 13c44133e009..e806c1866e36 100644 --- a/tools/testing/selftests/mm/page_frag/page_frag_test.c +++ b/tools/testing/selftests/mm/page_frag/page_frag_test.c @@ -126,7 +126,7 @@ static int __init page_frag_test_init(void) u64 duration; int ret; - test_nc.va = NULL; + page_frag_cache_init(&test_nc); atomic_set(&nthreads, 2); init_completion(&wait); -- 2.33.0

10 months

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[PATCH net-next v23 2/7] mm: move the page fragment allocator from page_alloc into its own file

by Yunsheng Lin

Inspired by [1], move the page fragment allocator from page_alloc into its own c file and header file, as we are about to make more change for it to replace another page_frag implementation in sock.c As this patchset is going to replace 'struct page_frag' with 'struct page_frag_cache' in sched.h, including page_frag_cache.h in sched.h has a compiler error caused by interdependence between mm_types.h and mm.h for asm-offsets.c, see [2]. So avoid the compiler error by moving 'struct page_frag_cache' to mm_types_task.h as suggested by Alexander, see [3]. 1. https://lore.kernel.org/all/20230411160902.4134381-3-dhowells@redhat.com/ 2. https://lore.kernel.org/all/15623dac-9358-4597-b3ee-3694a5956920@gmail.com/ 3. https://lore.kernel.org/all/CAKgT0UdH1yD=LSCXFJ=YM_aiA4OomD-2wXykO42bizaWMt… CC: David Howells <dhowells(a)redhat.com> CC: Alexander Duyck <alexander.duyck(a)gmail.com> CC: Andrew Morton <akpm(a)linux-foundation.org> CC: Linux-MM <linux-mm(a)kvack.org> Signed-off-by: Yunsheng Lin <linyunsheng(a)huawei.com> Acked-by: Andrew Morton <akpm(a)linux-foundation.org> Reviewed-by: Alexander Duyck <alexanderduyck(a)fb.com> --- include/linux/gfp.h | 22 --- include/linux/mm_types.h | 18 --- include/linux/mm_types_task.h | 18 +++ include/linux/page_frag_cache.h | 31 ++++ include/linux/skbuff.h | 1 + mm/Makefile | 1 + mm/page_alloc.c | 136 ---------------- mm/page_frag_cache.c | 145 ++++++++++++++++++ .../selftests/mm/page_frag/page_frag_test.c | 2 +- 9 files changed, 197 insertions(+), 177 deletions(-) create mode 100644 include/linux/page_frag_cache.h create mode 100644 mm/page_frag_cache.c diff --git a/include/linux/gfp.h b/include/linux/gfp.h index a951de920e20..a0a6d25f883f 100644 --- a/include/linux/gfp.h +++ b/include/linux/gfp.h @@ -371,28 +371,6 @@ __meminit void *alloc_pages_exact_nid_noprof(int nid, size_t size, gfp_t gfp_mas extern void __free_pages(struct page *page, unsigned int order); extern void free_pages(unsigned long addr, unsigned int order); -struct page_frag_cache; -void page_frag_cache_drain(struct page_frag_cache *nc); -extern void __page_frag_cache_drain(struct page *page, unsigned int count); -void *__page_frag_alloc_align(struct page_frag_cache *nc, unsigned int fragsz, - gfp_t gfp_mask, unsigned int align_mask); - -static inline void *page_frag_alloc_align(struct page_frag_cache *nc, - unsigned int fragsz, gfp_t gfp_mask, - unsigned int align) -{ - WARN_ON_ONCE(!is_power_of_2(align)); - return __page_frag_alloc_align(nc, fragsz, gfp_mask, -align); -} - -static inline void *page_frag_alloc(struct page_frag_cache *nc, - unsigned int fragsz, gfp_t gfp_mask) -{ - return __page_frag_alloc_align(nc, fragsz, gfp_mask, ~0u); -} - -extern void page_frag_free(void *addr); - #define __free_page(page) __free_pages((page), 0) #define free_page(addr) free_pages((addr), 0) diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 6e3bdf8e38bc..92314ef2d978 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -521,9 +521,6 @@ static_assert(sizeof(struct ptdesc) <= sizeof(struct page)); */ #define STRUCT_PAGE_MAX_SHIFT (order_base_2(sizeof(struct page))) -#define PAGE_FRAG_CACHE_MAX_SIZE __ALIGN_MASK(32768, ~PAGE_MASK) -#define PAGE_FRAG_CACHE_MAX_ORDER get_order(PAGE_FRAG_CACHE_MAX_SIZE) - /* * page_private can be used on tail pages. However, PagePrivate is only * checked by the VM on the head page. So page_private on the tail pages @@ -542,21 +539,6 @@ static inline void *folio_get_private(struct folio *folio) return folio->private; } -struct page_frag_cache { - void * va; -#if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE) - __u16 offset; - __u16 size; -#else - __u32 offset; -#endif - /* we maintain a pagecount bias, so that we dont dirty cache line - * containing page->_refcount every time we allocate a fragment. - */ - unsigned int pagecnt_bias; - bool pfmemalloc; -}; - typedef unsigned long vm_flags_t; /* diff --git a/include/linux/mm_types_task.h b/include/linux/mm_types_task.h index bff5706b76e1..0ac6daebdd5c 100644 --- a/include/linux/mm_types_task.h +++ b/include/linux/mm_types_task.h @@ -8,6 +8,7 @@ * (These are defined separately to decouple sched.h from mm_types.h as much as possible.) */ +#include <linux/align.h> #include <linux/types.h> #include <asm/page.h> @@ -43,6 +44,23 @@ struct page_frag { #endif }; +#define PAGE_FRAG_CACHE_MAX_SIZE __ALIGN_MASK(32768, ~PAGE_MASK) +#define PAGE_FRAG_CACHE_MAX_ORDER get_order(PAGE_FRAG_CACHE_MAX_SIZE) +struct page_frag_cache { + void *va; +#if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE) + __u16 offset; + __u16 size; +#else + __u32 offset; +#endif + /* we maintain a pagecount bias, so that we dont dirty cache line + * containing page->_refcount every time we allocate a fragment. + */ + unsigned int pagecnt_bias; + bool pfmemalloc; +}; + /* Track pages that require TLB flushes */ struct tlbflush_unmap_batch { #ifdef CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH diff --git a/include/linux/page_frag_cache.h b/include/linux/page_frag_cache.h new file mode 100644 index 000000000000..67ac8626ed9b --- /dev/null +++ b/include/linux/page_frag_cache.h @@ -0,0 +1,31 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef _LINUX_PAGE_FRAG_CACHE_H +#define _LINUX_PAGE_FRAG_CACHE_H + +#include <linux/log2.h> +#include <linux/mm_types_task.h> +#include <linux/types.h> + +void page_frag_cache_drain(struct page_frag_cache *nc); +void __page_frag_cache_drain(struct page *page, unsigned int count); +void *__page_frag_alloc_align(struct page_frag_cache *nc, unsigned int fragsz, + gfp_t gfp_mask, unsigned int align_mask); + +static inline void *page_frag_alloc_align(struct page_frag_cache *nc, + unsigned int fragsz, gfp_t gfp_mask, + unsigned int align) +{ + WARN_ON_ONCE(!is_power_of_2(align)); + return __page_frag_alloc_align(nc, fragsz, gfp_mask, -align); +} + +static inline void *page_frag_alloc(struct page_frag_cache *nc, + unsigned int fragsz, gfp_t gfp_mask) +{ + return __page_frag_alloc_align(nc, fragsz, gfp_mask, ~0u); +} + +void page_frag_free(void *addr); + +#endif diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 48f1e0fa2a13..7adca0fa2602 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -31,6 +31,7 @@ #include <linux/in6.h> #include <linux/if_packet.h> #include <linux/llist.h> +#include <linux/page_frag_cache.h> #include <net/flow.h> #if IS_ENABLED(CONFIG_NF_CONNTRACK) #include <linux/netfilter/nf_conntrack_common.h> diff --git a/mm/Makefile b/mm/Makefile index d5639b036166..dba52bb0da8a 100644 --- a/mm/Makefile +++ b/mm/Makefile @@ -65,6 +65,7 @@ page-alloc-$(CONFIG_SHUFFLE_PAGE_ALLOCATOR) += shuffle.o memory-hotplug-$(CONFIG_MEMORY_HOTPLUG) += memory_hotplug.o obj-y += page-alloc.o +obj-y += page_frag_cache.o obj-y += init-mm.o obj-y += memblock.o obj-y += $(memory-hotplug-y) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 8afab64814dc..6ca2abce857b 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -4836,142 +4836,6 @@ void free_pages(unsigned long addr, unsigned int order) EXPORT_SYMBOL(free_pages); -/* - * Page Fragment: - * An arbitrary-length arbitrary-offset area of memory which resides - * within a 0 or higher order page. Multiple fragments within that page - * are individually refcounted, in the page's reference counter. - * - * The page_frag functions below provide a simple allocation framework for - * page fragments. This is used by the network stack and network device - * drivers to provide a backing region of memory for use as either an - * sk_buff->head, or to be used in the "frags" portion of skb_shared_info. - */ -static struct page *__page_frag_cache_refill(struct page_frag_cache *nc, - gfp_t gfp_mask) -{ - struct page *page = NULL; - gfp_t gfp = gfp_mask; - -#if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE) - gfp_mask = (gfp_mask & ~__GFP_DIRECT_RECLAIM) | __GFP_COMP | - __GFP_NOWARN | __GFP_NORETRY | __GFP_NOMEMALLOC; - page = alloc_pages_node(NUMA_NO_NODE, gfp_mask, - PAGE_FRAG_CACHE_MAX_ORDER); - nc->size = page ? PAGE_FRAG_CACHE_MAX_SIZE : PAGE_SIZE; -#endif - if (unlikely(!page)) - page = alloc_pages_node(NUMA_NO_NODE, gfp, 0); - - nc->va = page ? page_address(page) : NULL; - - return page; -} - -void page_frag_cache_drain(struct page_frag_cache *nc) -{ - if (!nc->va) - return; - - __page_frag_cache_drain(virt_to_head_page(nc->va), nc->pagecnt_bias); - nc->va = NULL; -} -EXPORT_SYMBOL(page_frag_cache_drain); - -void __page_frag_cache_drain(struct page *page, unsigned int count) -{ - VM_BUG_ON_PAGE(page_ref_count(page) == 0, page); - - if (page_ref_sub_and_test(page, count)) - free_unref_page(page, compound_order(page)); -} -EXPORT_SYMBOL(__page_frag_cache_drain); - -void *__page_frag_alloc_align(struct page_frag_cache *nc, - unsigned int fragsz, gfp_t gfp_mask, - unsigned int align_mask) -{ - unsigned int size = PAGE_SIZE; - struct page *page; - int offset; - - if (unlikely(!nc->va)) { -refill: - page = __page_frag_cache_refill(nc, gfp_mask); - if (!page) - return NULL; - -#if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE) - /* if size can vary use size else just use PAGE_SIZE */ - size = nc->size; -#endif - /* Even if we own the page, we do not use atomic_set(). - * This would break get_page_unless_zero() users. - */ - page_ref_add(page, PAGE_FRAG_CACHE_MAX_SIZE); - - /* reset page count bias and offset to start of new frag */ - nc->pfmemalloc = page_is_pfmemalloc(page); - nc->pagecnt_bias = PAGE_FRAG_CACHE_MAX_SIZE + 1; - nc->offset = size; - } - - offset = nc->offset - fragsz; - if (unlikely(offset < 0)) { - page = virt_to_page(nc->va); - - if (!page_ref_sub_and_test(page, nc->pagecnt_bias)) - goto refill; - - if (unlikely(nc->pfmemalloc)) { - free_unref_page(page, compound_order(page)); - goto refill; - } - -#if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE) - /* if size can vary use size else just use PAGE_SIZE */ - size = nc->size; -#endif - /* OK, page count is 0, we can safely set it */ - set_page_count(page, PAGE_FRAG_CACHE_MAX_SIZE + 1); - - /* reset page count bias and offset to start of new frag */ - nc->pagecnt_bias = PAGE_FRAG_CACHE_MAX_SIZE + 1; - offset = size - fragsz; - if (unlikely(offset < 0)) { - /* - * The caller is trying to allocate a fragment - * with fragsz > PAGE_SIZE but the cache isn't big - * enough to satisfy the request, this may - * happen in low memory conditions. - * We don't release the cache page because - * it could make memory pressure worse - * so we simply return NULL here. - */ - return NULL; - } - } - - nc->pagecnt_bias--; - offset &= align_mask; - nc->offset = offset; - - return nc->va + offset; -} -EXPORT_SYMBOL(__page_frag_alloc_align); - -/* - * Frees a page fragment allocated out of either a compound or order 0 page. - */ -void page_frag_free(void *addr) -{ - struct page *page = virt_to_head_page(addr); - - if (unlikely(put_page_testzero(page))) - free_unref_page(page, compound_order(page)); -} -EXPORT_SYMBOL(page_frag_free); - static void *make_alloc_exact(unsigned long addr, unsigned int order, size_t size) { diff --git a/mm/page_frag_cache.c b/mm/page_frag_cache.c new file mode 100644 index 000000000000..609a485cd02a --- /dev/null +++ b/mm/page_frag_cache.c @@ -0,0 +1,145 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Page fragment allocator + * + * Page Fragment: + * An arbitrary-length arbitrary-offset area of memory which resides within a + * 0 or higher order page. Multiple fragments within that page are + * individually refcounted, in the page's reference counter. + * + * The page_frag functions provide a simple allocation framework for page + * fragments. This is used by the network stack and network device drivers to + * provide a backing region of memory for use as either an sk_buff->head, or to + * be used in the "frags" portion of skb_shared_info. + */ + +#include <linux/export.h> +#include <linux/gfp_types.h> +#include <linux/init.h> +#include <linux/mm.h> +#include <linux/page_frag_cache.h> +#include "internal.h" + +static struct page *__page_frag_cache_refill(struct page_frag_cache *nc, + gfp_t gfp_mask) +{ + struct page *page = NULL; + gfp_t gfp = gfp_mask; + +#if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE) + gfp_mask = (gfp_mask & ~__GFP_DIRECT_RECLAIM) | __GFP_COMP | + __GFP_NOWARN | __GFP_NORETRY | __GFP_NOMEMALLOC; + page = alloc_pages_node(NUMA_NO_NODE, gfp_mask, + PAGE_FRAG_CACHE_MAX_ORDER); + nc->size = page ? PAGE_FRAG_CACHE_MAX_SIZE : PAGE_SIZE; +#endif + if (unlikely(!page)) + page = alloc_pages_node(NUMA_NO_NODE, gfp, 0); + + nc->va = page ? page_address(page) : NULL; + + return page; +} + +void page_frag_cache_drain(struct page_frag_cache *nc) +{ + if (!nc->va) + return; + + __page_frag_cache_drain(virt_to_head_page(nc->va), nc->pagecnt_bias); + nc->va = NULL; +} +EXPORT_SYMBOL(page_frag_cache_drain); + +void __page_frag_cache_drain(struct page *page, unsigned int count) +{ + VM_BUG_ON_PAGE(page_ref_count(page) == 0, page); + + if (page_ref_sub_and_test(page, count)) + free_unref_page(page, compound_order(page)); +} +EXPORT_SYMBOL(__page_frag_cache_drain); + +void *__page_frag_alloc_align(struct page_frag_cache *nc, + unsigned int fragsz, gfp_t gfp_mask, + unsigned int align_mask) +{ + unsigned int size = PAGE_SIZE; + struct page *page; + int offset; + + if (unlikely(!nc->va)) { +refill: + page = __page_frag_cache_refill(nc, gfp_mask); + if (!page) + return NULL; + +#if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE) + /* if size can vary use size else just use PAGE_SIZE */ + size = nc->size; +#endif + /* Even if we own the page, we do not use atomic_set(). + * This would break get_page_unless_zero() users. + */ + page_ref_add(page, PAGE_FRAG_CACHE_MAX_SIZE); + + /* reset page count bias and offset to start of new frag */ + nc->pfmemalloc = page_is_pfmemalloc(page); + nc->pagecnt_bias = PAGE_FRAG_CACHE_MAX_SIZE + 1; + nc->offset = size; + } + + offset = nc->offset - fragsz; + if (unlikely(offset < 0)) { + page = virt_to_page(nc->va); + + if (!page_ref_sub_and_test(page, nc->pagecnt_bias)) + goto refill; + + if (unlikely(nc->pfmemalloc)) { + free_unref_page(page, compound_order(page)); + goto refill; + } + +#if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE) + /* if size can vary use size else just use PAGE_SIZE */ + size = nc->size; +#endif + /* OK, page count is 0, we can safely set it */ + set_page_count(page, PAGE_FRAG_CACHE_MAX_SIZE + 1); + + /* reset page count bias and offset to start of new frag */ + nc->pagecnt_bias = PAGE_FRAG_CACHE_MAX_SIZE + 1; + offset = size - fragsz; + if (unlikely(offset < 0)) { + /* + * The caller is trying to allocate a fragment + * with fragsz > PAGE_SIZE but the cache isn't big + * enough to satisfy the request, this may + * happen in low memory conditions. + * We don't release the cache page because + * it could make memory pressure worse + * so we simply return NULL here. + */ + return NULL; + } + } + + nc->pagecnt_bias--; + offset &= align_mask; + nc->offset = offset; + + return nc->va + offset; +} +EXPORT_SYMBOL(__page_frag_alloc_align); + +/* + * Frees a page fragment allocated out of either a compound or order 0 page. + */ +void page_frag_free(void *addr) +{ + struct page *page = virt_to_head_page(addr); + + if (unlikely(put_page_testzero(page))) + free_unref_page(page, compound_order(page)); +} +EXPORT_SYMBOL(page_frag_free); diff --git a/tools/testing/selftests/mm/page_frag/page_frag_test.c b/tools/testing/selftests/mm/page_frag/page_frag_test.c index 912d97b99107..13c44133e009 100644 --- a/tools/testing/selftests/mm/page_frag/page_frag_test.c +++ b/tools/testing/selftests/mm/page_frag/page_frag_test.c @@ -6,12 +6,12 @@ * Copyright (C) 2024 Yunsheng Lin <linyunsheng(a)huawei.com> */ -#include <linux/mm.h> #include <linux/module.h> #include <linux/cpumask.h> #include <linux/completion.h> #include <linux/ptr_ring.h> #include <linux/kthread.h> +#include <linux/page_frag_cache.h> #define TEST_FAILED_PREFIX "page_frag_test failed: " -- 2.33.0

10 months

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[PATCH v4 00/11] iommufd: Add vIOMMU infrastructure (Part-1)

by Nicolin Chen

This series introduces a new vIOMMU infrastructure and related ioctls. IOMMUFD has been using the HWPT infrastructure for all cases, including a nested IO page table support. Yet, there're limitations for an HWPT-based structure to support some advanced HW-accelerated features, such as CMDQV on NVIDIA Grace, and HW-accelerated vIOMMU on AMD. Even for a multi-IOMMU environment, it is not straightforward for nested HWPTs to share the same parent HWPT (stage-2 IO pagetable), with the HWPT infrastructure alone: a parent HWPT typically hold one stage-2 IO pagetable and tag it with only one ID in the cache entries. When sharing one large stage-2 IO pagetable across physical IOMMU instances, that one ID may not always be available across all the IOMMU instances. In other word, it's ideal for SW to have a different container for the stage-2 IO pagetable so it can hold another ID that's available. For this "different container", add vIOMMU, an additional layer to hold extra virtualization information: _______________________________________________________________________ | iommufd (with vIOMMU) | | | | [5] | | _____________ | | | | | | |----------------| vIOMMU | | | | | | | | | | | | | | [1] | | [4] [2] | | | ______ | | _____________ ________ | | | | | | [3] | | | | | | | | | IOAS |<---|(HWPT_PAGING)|<---| HWPT_NESTED |<--| DEVICE | | | | |______| |_____________| |_____________| |________| | | | | | | | | |______|________|______________|__________________|_______________|_____| | | | | | ______v_____ | ______v_____ ______v_____ ___v__ | struct | | PFN | (paging) | | (nested) | |struct| |iommu_device| |------>|iommu_domain|<----|iommu_domain|<----|device| |____________| storage|____________| |____________| |______| The vIOMMU object should be seen as a slice of a physical IOMMU instance that is passed to or shared with a VM. That can be some HW/SW resources: - Security namespace for guest owned ID, e.g. guest-controlled cache tags - Access to a sharable nesting parent pagetable across physical IOMMUs - Virtualization of various platforms IDs, e.g. RIDs and others - Delivery of paravirtualized invalidation - Direct assigned invalidation queues - Direct assigned interrupts - Non-affiliated event reporting On a multi-IOMMU system, the vIOMMU object must be instanced to the number of the physical IOMMUs that are passed to (via devices) a guest VM, while being able to hold the shareable parent HWPT. Each vIOMMU then just needs to allocate its own individual ID to tag its own cache: ---------------------------- ---------------- | | paging_hwpt0 | | hwpt_nested0 |--->| viommu0 ------------------ ---------------- | | IDx | ---------------------------- ---------------------------- ---------------- | | paging_hwpt0 | | hwpt_nested1 |--->| viommu1 ------------------ ---------------- | | IDy | ---------------------------- As an initial part-1, add IOMMUFD_CMD_VIOMMU_ALLOC ioctl for an allocation only. And implement it in arm-smmu-v3 driver as a real world use case. More vIOMMU-based structs and ioctls will be introduced in the follow-up series to support vDEVICE, vIRQ (vEVENT) and vQUEUE objects. Although we repurposed the vIOMMU object from an earlier RFC, just for a referece: https://lore.kernel.org/all/cover.1712978212.git.nicolinc@nvidia.com/ This series is on Github: https://github.com/nicolinc/iommufd/commits/iommufd_viommu_p1-v4 (paring QEMU branch for testing will be provided with the part2 series) Changelog v4 * Added "Reviewed-by" from Jason * Dropped IOMMU_VIOMMU_TYPE_DEFAULT support * Dropped iommufd_object_alloc_elm renamings * Renamed iommufd's viommu_api.c to driver.c * Reworked iommufd_viommu_alloc helper * Added a separate iommufd_hwpt_nested_alloc_for_viommu function for hwpt_nested allocations on a vIOMMU, and added comparison between viommu->iommu_dev->ops and dev_iommu_ops(idev->dev) * Replaced s2_parent with vsmmu in arm_smmu_nested_domain * Replaced domain_alloc_user in iommu_ops with domain_alloc_nested in viommu_ops * Replaced wait_queue_head_t with a completion, to delay the unplug of mock_iommu_dev * Corrected documentation graph that was missing struct iommu_device * Added an iommufd_verify_unfinalized_object helper to verify driver- allocated vIOMMU/vDEVICE objects * Added missing test cases for TEST_LENGTH and fail_nth v3 https://lore.kernel.org/all/cover.1728491453.git.nicolinc@nvidia.com/ * Rebased on top of Jason's nesting v3 series https://lore.kernel.org/all/0-v3-e2e16cd7467f+2a6a1-smmuv3_nesting_jgg@nvid… * Split the series into smaller parts * Added Jason's Reviewed-by * Added back viommu->iommu_dev * Added support for driver-allocated vIOMMU v.s. core-allocated * Dropped arm_smmu_cache_invalidate_user * Added an iommufd_test_wait_for_users() in selftest * Reworked test code to make viommu an individual FIXTURE * Added missing TEST_LENGTH case for the new ioctl command v2 https://lore.kernel.org/all/cover.1724776335.git.nicolinc@nvidia.com/ * Limited vdev_id to one per idev * Added a rw_sem to protect the vdev_id list * Reworked driver-level APIs with proper lockings * Added a new viommu_api file for IOMMUFD_DRIVER config * Dropped useless iommu_dev point from the viommu structure * Added missing index numnbers to new types in the uAPI header * Dropped IOMMU_VIOMMU_INVALIDATE uAPI; Instead, reuse the HWPT one * Reworked mock_viommu_cache_invalidate() using the new iommu helper * Reordered details of set/unset_vdev_id handlers for proper lockings v1 https://lore.kernel.org/all/cover.1723061377.git.nicolinc@nvidia.com/ Thanks! Nicolin Nicolin Chen (11): iommufd: Move struct iommufd_object to public iommufd header iommufd: Introduce IOMMUFD_OBJ_VIOMMU and its related struct iommufd: Add iommufd_verify_unfinalized_object iommufd/viommu: Add IOMMU_VIOMMU_ALLOC ioctl iommufd: Add domain_alloc_nested op to iommufd_viommu_ops iommufd: Allow pt_id to carry viommu_id for IOMMU_HWPT_ALLOC iommufd/selftest: Add refcount to mock_iommu_device iommufd/selftest: Add IOMMU_VIOMMU_TYPE_SELFTEST iommufd/selftest: Add IOMMU_VIOMMU_ALLOC test coverage Documentation: userspace-api: iommufd: Update vIOMMU iommu/arm-smmu-v3: Add IOMMU_VIOMMU_TYPE_ARM_SMMUV3 support drivers/iommu/iommufd/Makefile | 5 +- drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 26 +++--- drivers/iommu/iommufd/iommufd_private.h | 36 ++------ drivers/iommu/iommufd/iommufd_test.h | 2 + include/linux/iommu.h | 14 +++ include/linux/iommufd.h | 89 +++++++++++++++++++ include/uapi/linux/iommufd.h | 56 ++++++++++-- tools/testing/selftests/iommu/iommufd_utils.h | 28 ++++++ .../arm/arm-smmu-v3/arm-smmu-v3-iommufd.c | 79 ++++++++++------ drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 9 +- drivers/iommu/iommufd/driver.c | 38 ++++++++ drivers/iommu/iommufd/hw_pagetable.c | 69 +++++++++++++- drivers/iommu/iommufd/main.c | 58 ++++++------ drivers/iommu/iommufd/selftest.c | 73 +++++++++++++-- drivers/iommu/iommufd/viommu.c | 85 ++++++++++++++++++ tools/testing/selftests/iommu/iommufd.c | 78 ++++++++++++++++ .../selftests/iommu/iommufd_fail_nth.c | 11 +++ Documentation/userspace-api/iommufd.rst | 69 +++++++++++++- 18 files changed, 701 insertions(+), 124 deletions(-) create mode 100644 drivers/iommu/iommufd/driver.c create mode 100644 drivers/iommu/iommufd/viommu.c -- 2.43.0

10 months

4
35
0 0

[PATCH] selftests/mount_setattr: fix idmap_mount_tree_invalid failed to run

by zhouyuhang

From: zhouyuhang <zhouyuhang(a)kylinos.cn> Test case idmap_mount_tree_invalid failed to run on the newer kernel with the following output: # RUN mount_setattr_idmapped.idmap_mount_tree_invalid ... # mount_setattr_test.c:1428:idmap_mount_tree_invalid:Expected sys_mount_setattr(open_tree_fd, "", AT_EMPTY_PATH, &attr, sizeof(attr)) (0) ! = 0 (0) # idmap_mount_tree_invalid: Test terminated by assertion This is because tmpfs is mounted at "/mnt/A", and tmpfs already contains the flag FS_ALLOW_IDMAP after the commit 7a80e5b8c6fa ("shmem: support idmapped mounts for tmpfs"). So calling sys_mount_setattr here returns 0 instead of -EINVAL as expected. Ramfs is mounted at "/mnt/B" and does not support idmap mounts. So we can use "/mnt/B" instead of "/mnt/A" to make the test run successfully with the following output: # Starting 1 tests from 1 test cases. # RUN mount_setattr_idmapped.idmap_mount_tree_invalid ... # OK mount_setattr_idmapped.idmap_mount_tree_invalid ok 1 mount_setattr_idmapped.idmap_mount_tree_invalid # PASSED: 1 / 1 tests passed. Signed-off-by: zhouyuhang <zhouyuhang(a)kylinos.cn> --- tools/testing/selftests/mount_setattr/mount_setattr_test.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/testing/selftests/mount_setattr/mount_setattr_test.c b/tools/testing/selftests/mount_setattr/mount_setattr_test.c index c6a8c732b802..54552c19bc24 100644 --- a/tools/testing/selftests/mount_setattr/mount_setattr_test.c +++ b/tools/testing/selftests/mount_setattr/mount_setattr_test.c @@ -1414,7 +1414,7 @@ TEST_F(mount_setattr_idmapped, idmap_mount_tree_invalid) ASSERT_EQ(expected_uid_gid(-EBADF, "/tmp/B/b", 0, 0, 0), 0); ASSERT_EQ(expected_uid_gid(-EBADF, "/tmp/B/BB/b", 0, 0, 0), 0); - open_tree_fd = sys_open_tree(-EBADF, "/mnt/A", + open_tree_fd = sys_open_tree(-EBADF, "/mnt/B", AT_RECURSIVE | AT_EMPTY_PATH | AT_NO_AUTOMOUNT | -- 2.27.0

10 months

2
3
0 0

[PATCH v2] selftests: tmpfs: Add kselftest support to tmpfs

by Shivam Chaudhary

Add kselftest support for open, linkat, unshare, mount tests - Replace direct error handling with `ksft_test_result_*` macros for better reporting of test outcomes. - Add `ksft_print_header()` and `ksft_set_plan()` to structure test outputs more effectively. - Introduce the helper function `is_unshare()` to handle unshare() related checks. - Improve the test flow by adding more detailed pass/fail reporting for unshare, mounting, file opening, and linking operations. - Skip the test if it's not run as root, providing an appropriate Warning. Test logs: Before change: - Without root error: unshare, errno 1 - With root No, output After change: - Without root TAP version 13 1..1 ok 1 # SKIP This test needs root to run - With root TAP version 13 1..1 ok 1 unshare(): we have a new mount namespace. 1..2 ok 2 mount(): Root filesystem private mount: Success 1..3 ok 3 mount(): Mounting tmpfs on /tmp: Success 1..4 ok 4 openat(): Open first temporary file: Success 1..5 ok 5 linkat(): Linking the temporary file: Success 1..6 ok 6 openat(): Opening the second temporary file: Success # Totals: pass:6 fail:0 xfail:0 xpass:0 skip:0 error:0 Signed-off-by: Shivam Chaudhary <cvam0000(a)gmail.com> --- Notes: Changes in v2: - Make the commit message more clear. link to v1: https://lore.kernel.org/all/20241024200228.1075840-1-cvam0000@gmail.com/T/#u .../selftests/tmpfs/bug-link-o-tmpfile.c | 72 +++++++++++++++---- 1 file changed, 58 insertions(+), 14 deletions(-) diff --git a/tools/testing/selftests/tmpfs/bug-link-o-tmpfile.c b/tools/testing/selftests/tmpfs/bug-link-o-tmpfile.c index b5c3ddb90942..26dea19c1614 100644 --- a/tools/testing/selftests/tmpfs/bug-link-o-tmpfile.c +++ b/tools/testing/selftests/tmpfs/bug-link-o-tmpfile.c @@ -23,45 +23,89 @@ #include <sys/mount.h> #include <unistd.h> -int main(void) -{ - int fd; +#include "../kselftest.h" - if (unshare(CLONE_NEWNS) == -1) { +static int is_unshare(int flag) +{ + if (unshare(flag) == -1) { if (errno == ENOSYS || errno == EPERM) { - fprintf(stderr, "error: unshare, errno %d\n", errno); - return 4; + ksft_test_result_fail("error: unshare, errno %d\n", errno); + return -1; // Return -1 for failure } fprintf(stderr, "error: unshare, errno %d\n", errno); + return -1; + } + + return 0; // Return 0 for success +} + +int main(void) +{ + int fd; + + // Setting up kselftest framework + ksft_print_header(); + ksft_set_plan(1); + + // Check if test is run as root + if (geteuid()) { + ksft_test_result_skip("This test needs root to run!\n"); return 1; } - if (mount(NULL, "/", NULL, MS_PRIVATE|MS_REC, NULL) == -1) { - fprintf(stderr, "error: mount '/', errno %d\n", errno); + + if (is_unshare(CLONE_NEWNS) == 0) { + ksft_test_result_pass("unshare(): we have a new mount namespace.\n"); + } else { + ksft_test_result_fail("unshare(): failed\n"); return 1; } + ksft_set_plan(2); + + if (mount(NULL, "/", NULL, MS_PRIVATE | MS_REC, NULL) == -1) { + ksft_test_result_fail("mount(): Root filesystem private mount: Fail %d\n", errno); + return 1; + } else { + ksft_test_result_pass("mount(): Root filesystem private mount: Success\n"); + } + + ksft_set_plan(3); /* Our heroes: 1 root inode, 1 O_TMPFILE inode, 1 permanent inode. */ if (mount(NULL, "/tmp", "tmpfs", 0, "nr_inodes=3") == -1) { - fprintf(stderr, "error: mount tmpfs, errno %d\n", errno); + ksft_test_result_fail("mount(): Mounting tmpfs on /tmp: Fail %d\n", errno); return 1; + } else { + ksft_test_result_pass("mount(): Mounting tmpfs on /tmp: Success\n"); } - fd = openat(AT_FDCWD, "/tmp", O_WRONLY|O_TMPFILE, 0600); + ksft_set_plan(4); + fd = openat(AT_FDCWD, "/tmp", O_WRONLY | O_TMPFILE, 0600); if (fd == -1) { - fprintf(stderr, "error: open 1, errno %d\n", errno); + ksft_test_result_fail("openat(): Open first temporary file: Fail %d\n", errno); return 1; + } else { + ksft_test_result_pass("openat(): Open first temporary file: Success\n"); } + + ksft_set_plan(5); if (linkat(fd, "", AT_FDCWD, "/tmp/1", AT_EMPTY_PATH) == -1) { - fprintf(stderr, "error: linkat, errno %d\n", errno); + ksft_test_result_fail("linkat(): Linking the temporary file: Fail %d\n", errno); + close(fd); // Ensure fd is closed on failure return 1; + } else { + ksft_test_result_pass("linkat(): Linking the temporary file: Success\n"); } close(fd); - fd = openat(AT_FDCWD, "/tmp", O_WRONLY|O_TMPFILE, 0600); + ksft_set_plan(6); + fd = openat(AT_FDCWD, "/tmp", O_WRONLY | O_TMPFILE, 0600); if (fd == -1) { - fprintf(stderr, "error: open 2, errno %d\n", errno); + ksft_test_result_fail("openat(): Opening the second temporary file: Fail %d\n", errno); return 1; + } else { + ksft_test_result_pass("openat(): Opening the second temporary file: Success\n"); } + ksft_exit_pass(); return 0; } -- 2.34.1

10 months

2
1
0 0

[PATCH v2] lib/math: Add int_sqrt test suite

by Luis Felipe Hernandez

Adds test suite for integer based square root function. The test suite is designed to verify the correctness of the int_sqrt math library function. Signed-off-by: Luis Felipe Hernandez <luis.hernandez093(a)gmail.com> --- lib/Kconfig.debug | 16 +++++++++++ lib/math/Makefile | 1 + lib/math/tests/Makefile | 1 + lib/math/tests/int_sqrt_kunit.c | 51 +++++++++++++++++++++++++++++++++ 4 files changed, 69 insertions(+) create mode 100644 lib/math/tests/int_sqrt_kunit.c diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 7312ae7c3cc5..772c681dff3e 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -2993,6 +2993,22 @@ config TEST_OBJPOOL If unsure, say N. +config INT_SQRT_KUNIT_TEST + tristate "Integer square root test test" if !KUNIT_ALL_TESTS + depends on KUNIT + default KUNIT_ALL_TESTS + help + This option enables the KUnit test suite for the int_sqrt function, + which performs square root calculation. The test suite checks + various scenarios, including edge cases, to ensure correctness. + + Enabling this option will include tests that check various scenarios + and edge cases to ensure the accuracy and reliability of the square root + function. + + If unsure, say N + + endif # RUNTIME_TESTING_MENU config ARCH_USE_MEMTEST diff --git a/lib/math/Makefile b/lib/math/Makefile index 3ef11305f8d2..25bcb968b369 100644 --- a/lib/math/Makefile +++ b/lib/math/Makefile @@ -9,3 +9,4 @@ obj-$(CONFIG_INT_POW_TEST) += tests/int_pow_kunit.o obj-$(CONFIG_TEST_DIV64) += test_div64.o obj-$(CONFIG_TEST_MULDIV64) += test_mul_u64_u64_div_u64.o obj-$(CONFIG_RATIONAL_KUNIT_TEST) += rational-test.o +obj-y += tests/ diff --git a/lib/math/tests/Makefile b/lib/math/tests/Makefile index 6a169123320a..e1a79f093b2d 100644 --- a/lib/math/tests/Makefile +++ b/lib/math/tests/Makefile @@ -1,3 +1,4 @@ # SPDX-License-Identifier: GPL-2.0-only obj-$(CONFIG_INT_POW_TEST) += int_pow_kunit.o +obj-$(CONFIG_INT_SQRT_KUNIT_TEST) += int_sqrt_kunit.o diff --git a/lib/math/tests/int_sqrt_kunit.c b/lib/math/tests/int_sqrt_kunit.c new file mode 100644 index 000000000000..a93aba31cd05 --- /dev/null +++ b/lib/math/tests/int_sqrt_kunit.c @@ -0,0 +1,51 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#include <kunit/test.h> +#include <linux/math.h> +#include <linux/module.h> +#include <linux/string.h> +#include <limits.h> + +struct test_case_params { + unsigned long x; + unsigned long expected_result; + const char *name; +}; + +static const struct test_case_params params[] = { + { 0, 0, "edge-case: square root of 0" }, + { 4, 2, "perfect square: square root of 4" }, + { 81, 9, "perfect square: square root of 9" }, + { 2, 1, "non-perfect square: square root of 2" }, + { 5, 2, "non-perfect square: square root of 5"}, + { ULONG_MAX, 4294967295, "large input"}, +}; + +static void get_desc(const struct test_case_params *tc, char *desc) +{ + strscpy(desc, tc->name, KUNIT_PARAM_DESC_SIZE); +} + +KUNIT_ARRAY_PARAM(int_sqrt, params, get_desc); + +static void int_sqrt_test(struct kunit *test) +{ + const struct test_case_params *tc = (const struct test_case_params *)test->param_value; + + KUNIT_EXPECT_EQ(test, tc->expected_result, int_sqrt(tc->x)); +} + +static struct kunit_case math_int_sqrt_test_cases[] = { + KUNIT_CASE_PARAM(int_sqrt_test, int_sqrt_gen_params), + {} +}; + +static struct kunit_suite int_sqrt_test_suite = { + .name = "math-int_sqrt", + .test_cases = math_int_sqrt_test_cases, +}; + +kunit_test_suites(&int_sqrt_test_suite); + +MODULE_DESCRIPTION("math.int_sqrt KUnit test suite"); +MODULE_LICENSE("GPL"); -- 2.47.0

10 months

3
5
0 0

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