June 2023 - Linux-kselftest-mirror

[PATCH v1 00/22] selftests/nolibc: add minimal kernel config support

by Zhangjin Wu

Willy, Thomas We just sent the 'selftests/nolibc: allow run with minimal kernel config' series [1], Here is the 'minimal' kernel config support, with both of them, it is possible to run nolibc-test for all architectures with oneline command and in less than ~30 minutes - 1 hour (not fullly measured yet): // run with tiny config + qemu-system // Note: rv32 and loongarch require to download the bios at first $ time make run-tiny-all QUIET_RUN=1 // run with default config + qemu-system $ time make run-default-all QUIET_RUN=1 // run with qemu-user $ time make run-user-all QUIET_RUN=1 Besides the 'tinyconfig' suggestion from Thomas, this patch also merge the generic part of my local powerpc porting (the extconfig to add additional console support). This is applied after the test report patchset [2] and the rv32 compile patchset [3], because all of them touched the same Makefile. Even without the 'selftests/nolibc: allow run with minimal kernel config' series [1], all of the tests can pass except the /proc/self/net related ones (We haven't enable CONFIG_NET in this patchset), the chmod_net one will be removed by Thomas from this patchset [4] for the wrong chmodable attribute issue of /proc/self/net, the link_cross one can be simply fixed up by using another /proc/self interface (like /proc/self/cmdline), which will be covered in our revision of the [1] series. Beside the core 'minimal' config support, some generic patch are added together to avoid patch conflicts. * selftests/nolibc: add test for -include /path/to/nolibc.h Add a test switch to allow run nolibc-test with nolibc.h * selftests/nolibc: print result to the screen too Let the run targets print results by default, allow disable by QUIET_RUN=1 * selftests/nolibc: allow use x86_64 toolchain for i386 Allow use x86_64 toolchains for i386 * selftests/nolibc: add menuconfig target for manual config a new 'menuconfig' target added for development and debugging * selftests/nolibc: add tinyconfig target a new 'tinyconfig' compare to 'defconfig', smaller and faster, but not enough for boot and print, require following 'extconfig' target * selftests/nolibc: allow customize extra kernel config options a new 'extconfig' allows to add extra config options for 'defconfig' and 'tinyconfig' * selftests/nolibc: add common extra config options selftests/nolibc: add power reset control support selftests/nolibc: add procfs, shmem and tmpfs Add common extra configs, the 3rd one (procfs, shmem and tmpfs) can be completely reverted after [1] series, but as discuss with Thomas, procfs may be still a hard requirement. * selftests/nolibc: add extra configs for i386 selftests/nolibc: add extra configs for x86_64 selftests/nolibc: add extra configs for arm64 selftests/nolibc: add extra configs for arm selftests/nolibc: add extra configs for mips selftests/nolibc: add extra configs for riscv32 selftests/nolibc: add extra configs for riscv64 selftests/nolibc: add extra configs for s390x selftests/nolibc: add extra configs for loongarch Add architecture specific extra configs to let kernel boot and nolibc-test print. The rv32 added here is only for test, it should not be merged before the missing 64bit syscalls are added (still wait for the merging of the __sysret and -ENOSYS patches). * selftests/nolibc: config default CROSS_COMPILE selftests/nolibc: add run-tiny and run-default both run-tiny and run-default are added to do config and run together, this easier test a log. * selftests/nolibc: allow run tests on all targets selftests/nolibc: detect bios existing to avoid hang Further allow do run-user, run-tiny and run-default for all architectures at once, the -all suffix is added to do so. Since some generic patches are still in review, before sending the left rv32 patches, I'm will send more generic patches later, the coming one is arch-xxx.h cleanup, and then, the 32bit powerpc porting support. For the compile speedup, the next step may be add architecture specific 'O' support, which may allow us rerun across architectures without mrproper, for a single architecture development, this 'minimal' config should be enough ;-) Thanks. Best regards, Zhangjin --- [1]: https://lore.kernel.org/lkml/cover.1687344643.git.falcon@tinylab.org/ [2]: https://lore.kernel.org/lkml/cover.1687156559.git.falcon@tinylab.org/ [3]: https://lore.kernel.org/linux-riscv/cover.1687176996.git.falcon@tinylab.org/ [4]: https://lore.kernel.org/lkml/20230624-proc-net-setattr-v1-0-73176812adee@we… Zhangjin Wu (22): selftests/nolibc: add test for -include /path/to/nolibc.h selftests/nolibc: print result to the screen too selftests/nolibc: allow use x86_64 toolchain for i386 selftests/nolibc: add menuconfig target for manual config selftests/nolibc: add tinyconfig target selftests/nolibc: allow customize extra kernel config options selftests/nolibc: add common extra config options selftests/nolibc: add power reset control support selftests/nolibc: add procfs, shmem and tmpfs selftests/nolibc: add extra configs for i386 selftests/nolibc: add extra configs for x86_64 selftests/nolibc: add extra configs for arm64 selftests/nolibc: add extra configs for arm selftests/nolibc: add extra configs for mips selftests/nolibc: add extra configs for riscv32 selftests/nolibc: add extra configs for riscv64 selftests/nolibc: add extra configs for s390x selftests/nolibc: add extra configs for loongarch selftests/nolibc: config default CROSS_COMPILE selftests/nolibc: add run-tiny and run-default selftests/nolibc: allow run tests on all targets selftests/nolibc: detect bios existing to avoid hang tools/testing/selftests/nolibc/Makefile | 125 ++++++++++++++++++++++-- 1 file changed, 119 insertions(+), 6 deletions(-) -- 2.25.1

1 year, 5 months

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[PATCH 0/2] kselftest/alsa: Decrease pcm-test duration to avoid timeouts

by Nícolas F. R. A. Prado

This series decreases the pcm-test duration in order to avoid timeouts by first moving the audio stream duration to a variable and subsequently decreasing it. Nícolas F. R. A. Prado (2): kselftest/alsa: pcm-test: Move stream duration and margin to variables kselftest/alsa: pcm-test: Decrease stream duration from 4 to 2 seconds tools/testing/selftests/alsa/pcm-test.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) -- 2.41.0

1 year, 5 months

5
15
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[PATCH] Documentation: mm/memfd: vm.memfd_noexec

by jeffxu＠chromium.org

From: Jeff Xu <jeffxu(a)google.com> Add documentation for sysctl vm.memfd_noexec Link:https://lore.kernel.org/linux-mm/CABi2SkXUX_QqTQ10Yx9bBUGpN1wByOi_=gZU… Reported-by: Dominique Martinet <asmadeus(a)codewreck.org> Signed-off-by: Jeff Xu <jeffxu(a)google.com> --- Documentation/admin-guide/sysctl/vm.rst | 29 +++++++++++++++++++++++++ 1 file changed, 29 insertions(+) diff --git a/Documentation/admin-guide/sysctl/vm.rst b/Documentation/admin-guide/sysctl/vm.rst index 45ba1f4dc004..71923c3d7044 100644 --- a/Documentation/admin-guide/sysctl/vm.rst +++ b/Documentation/admin-guide/sysctl/vm.rst @@ -424,6 +424,35 @@ e.g., up to one or two maps per allocation. The default value is 65530. +memfd_noexec: +============= +This pid namespaced sysctl controls memfd_create(). + +The new MFD_NOEXEC_SEAL and MFD_EXEC flags of memfd_create() allows +application to set executable bit at creation time. + +When MFD_NOEXEC_SEAL is set, memfd is created without executable bit +(mode:0666), and sealed with F_SEAL_EXEC, so it can't be chmod to +be executable (mode: 0777) after creation. + +when MFD_EXEC flag is set, memfd is created with executable bit +(mode:0777), this is the same as the old behavior of memfd_create. + +The new pid namespaced sysctl vm.memfd_noexec has 3 values: +0: memfd_create() without MFD_EXEC nor MFD_NOEXEC_SEAL acts like + MFD_EXEC was set. +1: memfd_create() without MFD_EXEC nor MFD_NOEXEC_SEAL acts like + MFD_NOEXEC_SEAL was set. +2: memfd_create() without MFD_NOEXEC_SEAL will be rejected. + +The default value is 0. + +Once set, it can't be downgraded at runtime, i.e. 2=>1, 1=>0 +are denied. + +This is pid namespaced sysctl, child processes inherit the parent +process's pid at the time of fork. Changes to the parent process +after fork are not automatically propagated to the child process. memory_failure_early_kill: ========================== -- 2.41.0.255.g8b1d071c50-goog

1 year, 5 months

2
1
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[RESEND PATCH] selftests/mincore: fix skip condition for check_huge_pages test

by Ricardo Cañuelo

The check_huge_pages test was failing instead of skipping on qemu-armv7 because the skip condition wasn't handled properly. Add an additional check to fix it. Signed-off-by: Ricardo Cañuelo <ricardo.canuelo(a)collabora.com> Reported-by: Naresh Kamboju <naresh.kamboju(a)linaro.org> Reported-by: Linux Kernel Functional Testing <lkft(a)linaro.org> Reviewed-by: Muhammad Usama Anjum <usama.anjum(a)collabora.com> Tested-by: Anders Roxell <anders.roxell(a)linaro.org> Closes: https://lore.kernel.org/all/CA+G9fYuoB8Ug8PcTU-YGmemL7_eeEksXFihvxWF6OikD7s… --- tools/testing/selftests/mincore/mincore_selftest.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/mincore/mincore_selftest.c b/tools/testing/selftests/mincore/mincore_selftest.c index 4c88238fc8f0..6fb3eea5b6ee 100644 --- a/tools/testing/selftests/mincore/mincore_selftest.c +++ b/tools/testing/selftests/mincore/mincore_selftest.c @@ -150,8 +149,8 @@ TEST(check_huge_pages) MAP_PRIVATE | MAP_ANONYMOUS | MAP_HUGETLB, -1, 0); if (addr == MAP_FAILED) { - if (errno == ENOMEM) - SKIP(return, "No huge pages available."); + if (errno == ENOMEM || errno == EINVAL) + SKIP(return, "No huge pages available or CONFIG_HUGETLB_PAGE disabled."); else TH_LOG("mmap error: %s", strerror(errno)); } -- 2.25.1

1 year, 5 months

2
1
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[PATCH 0/2] proc: proc_setattr for /proc/$PID/net

by Thomas Weißschuh

/proc/$PID/net currently allows the setting of file attributes, in contrast to other /proc/$PID/ files and directories. This would break the nolibc testsuite so the first patch in the series removes the offending testcase. The "fix" for nolibc-test is intentionally kept trivial as the series will most likely go through the filesystem tree and if conflicts arise, it is obvious on how to resolve them. Technically this can lead to breakage of nolibc-test if an old nolibc-test is used with a newer kernel containing the fix. Note: Except for /proc itself this is the only "struct inode_operations" in fs/proc/ that is missing an implementation of setattr(). Signed-off-by: Thomas Weißschuh <linux(a)weissschuh.net> --- Thomas Weißschuh (2): selftests/nolibc: drop test chmod_net proc: use generic setattr() for /proc/$PID/net fs/proc/proc_net.c | 1 + tools/testing/selftests/nolibc/nolibc-test.c | 1 - 2 files changed, 1 insertion(+), 1 deletion(-) --- base-commit: a92b7d26c743b9dc06d520f863d624e94978a1d9 change-id: 20230624-proc-net-setattr-8f0a6b8eb2f5 Best regards, -- Thomas Weißschuh <linux(a)weissschuh.net>

1 year, 5 months

5
15
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[PATCH v4 0/9] cgroup/cpuset: Support remote partitions

by Waiman Long

v4: - [v3] https://lore.kernel.org/lkml/20230627005529.1564984-1-longman@redhat.com/ - Fix compilation problem reported by kernel test robot. v3: - [v2] https://lore.kernel.org/lkml/20230531163405.2200292-1-longman@redhat.com/ - Change the new control file from root-only "cpuset.cpus.reserve" to non-root "cpuset.cpus.exclusive" which lists the set of exclusive CPUs distributed down the hierarchy. - Add a patch to restrict boot-time isolated CPUs to isolated partitions only. - Update the test_cpuset_prs.sh test script and documentation accordingly. This patch series introduces a new cpuset control file "cpuset.cpus.exclusive" which must be a subset of "cpuset.cpus" and the parent's "cpuset.cpus.exclusive". This control file lists the exclusive CPUs to be distributed down the hierarchy. Any one of the exclusive CPUs can only be distributed to at most one child cpuset. Unlike "cpuset.cpus", invalid input to "cpuset.cpus.exclusive" will be rejected with an error. This new control file has no effect on the behavior of the cpuset until it turns into a partition root. At that point, its effective CPUs will be set to its exclusive CPUs unless some of them are offline. This patch series also introduces a new category of cpuset partition called remote partitions. The existing partition category where the partition roots have to be clustered around the root cgroup in a hierarchical way is now referred to as local partitions. A remote partition can be formed far from the root cgroup with no partition root parent. While local partitions can be created without touching "cpuset.cpus.exclusive" as it can be set automatically if a cpuset becomes a local partition root. Properly set "cpuset.cpus.exclusive" values down the hierarchy are required to create a remote partition. Both scheduling and isolated partitions can be formed in a remote partition. A local partition can be created under a remote partition. A remote partition, however, cannot be formed under a local partition for now. Modern container orchestration tools like Kubernetes use the cgroup hierarchy to manage different containers. And it is relying on other middleware like systemd to help managing it. If a container needs to use isolated CPUs, it is hard to get those with the local partitions as it will require the administrative parent cgroup to be a partition root too which tool like systemd may not be ready to manage. With this patch series, we allow the creation of remote partition far from the root. The container management tool can manage the "cpuset.cpus.exclusive" file without impacting the other cpuset files that are managed by other middlewares. Of course, invalid "cpuset.cpus.exclusive" values will be rejected and changes to "cpuset.cpus" can affect the value of "cpuset.cpus.exclusive" due to the requirement that it has to be a subset of the former control file. Waiman Long (9): cgroup/cpuset: Inherit parent's load balance state in v2 cgroup/cpuset: Extract out CS_CPU_EXCLUSIVE & CS_SCHED_LOAD_BALANCE handling cgroup/cpuset: Improve temporary cpumasks handling cgroup/cpuset: Allow suppression of sched domain rebuild in update_cpumasks_hier() cgroup/cpuset: Add cpuset.cpus.exclusive for v2 cgroup/cpuset: Introduce remote partition cgroup/cpuset: Check partition conflict with housekeeping setup cgroup/cpuset: Documentation update for partition cgroup/cpuset: Extend test_cpuset_prs.sh to test remote partition Documentation/admin-guide/cgroup-v2.rst | 100 +- kernel/cgroup/cpuset.c | 1347 ++++++++++++----- .../selftests/cgroup/test_cpuset_prs.sh | 398 +++-- 3 files changed, 1291 insertions(+), 554 deletions(-) -- 2.31.1

1 year, 5 months

2
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[PATCH bpf-next v4 0/7] Add SO_REUSEPORT support for TC bpf_sk_assign

by Lorenz Bauer

We want to replace iptables TPROXY with a BPF program at TC ingress. To make this work in all cases we need to assign a SO_REUSEPORT socket to an skb, which is currently prohibited. This series adds support for such sockets to bpf_sk_assing. I did some refactoring to cut down on the amount of duplicate code. The key to this is to use INDIRECT_CALL in the reuseport helpers. To show that this approach is not just beneficial to TC sk_assign I removed duplicate code for bpf_sk_lookup as well. Joint work with Daniel Borkmann. Signed-off-by: Lorenz Bauer <lmb(a)isovalent.com> --- Changes in v4: - WARN_ON_ONCE if reuseport socket is refcounted (Kuniyuki) - Use inet[6]_ehashfn_t to shorten function declarations (Kuniyuki) - Shuffle documentation patch around (Kuniyuki) - Update commit message to explain why IPv6 needs EXPORT_SYMBOL - Link to v3: https://lore.kernel.org/r/20230613-so-reuseport-v3-0-907b4cbb7b99@isovalent… Changes in v3: - Fix warning re udp_ehashfn and udp6_ehashfn (Simon) - Return higher scoring connected UDP reuseport sockets (Kuniyuki) - Fix ipv6 module builds - Link to v2: https://lore.kernel.org/r/20230613-so-reuseport-v2-0-b7c69a342613@isovalent… Changes in v2: - Correct commit abbrev length (Kuniyuki) - Reduce duplication (Kuniyuki) - Add checks on sk_state (Martin) - Split exporting inet[6]_lookup_reuseport into separate patch (Eric) --- Daniel Borkmann (1): selftests/bpf: Test that SO_REUSEPORT can be used with sk_assign helper Lorenz Bauer (6): udp: re-score reuseport groups when connected sockets are present net: export inet_lookup_reuseport and inet6_lookup_reuseport net: remove duplicate reuseport_lookup functions net: document inet[6]_lookup_reuseport sk_state requirements net: remove duplicate sk_lookup helpers bpf, net: Support SO_REUSEPORT sockets with bpf_sk_assign include/net/inet6_hashtables.h | 81 ++++++++- include/net/inet_hashtables.h | 74 +++++++- include/net/sock.h | 7 +- include/uapi/linux/bpf.h | 3 - net/core/filter.c | 2 - net/ipv4/inet_hashtables.c | 67 ++++--- net/ipv4/udp.c | 88 ++++----- net/ipv6/inet6_hashtables.c | 70 +++++--- net/ipv6/udp.c | 98 ++++------ tools/include/uapi/linux/bpf.h | 3 - tools/testing/selftests/bpf/network_helpers.c | 3 + .../selftests/bpf/prog_tests/assign_reuse.c | 197 +++++++++++++++++++++ .../selftests/bpf/progs/test_assign_reuse.c | 142 +++++++++++++++ 13 files changed, 656 insertions(+), 179 deletions(-) --- base-commit: 970308a7b544fa1c7ee98a2721faba3765be8dd8 change-id: 20230613-so-reuseport-e92c526173ee Best regards, -- Lorenz Bauer <lmb(a)isovalent.com>

1 year, 5 months

3
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[PATCH v7 00/19] Add iommufd physical device operations for replace and alloc hwpt

by Jason Gunthorpe

This is the basic functionality for iommufd to support iommufd_device_replace() and IOMMU_HWPT_ALLOC for physical devices. iommufd_device_replace() allows changing the HWPT associated with the device to a new IOAS or HWPT. Replace does this in way that failure leaves things unchanged, and utilizes the iommu iommu_group_replace_domain() API to allow the iommu driver to perform an optional non-disruptive change. IOMMU_HWPT_ALLOC allows HWPTs to be explicitly allocated by the user and used by attach or replace. At this point it isn't very useful since the HWPT is the same as the automatically managed HWPT from the IOAS. However a following series will allow userspace to customize the created HWPT. The implementation is complicated because we have to introduce some per-iommu_group memory in iommufd and redo how we think about multi-device groups to be more explicit. This solves all the locking problems in the prior attempts. This series is infrastructure work for the following series which: - Add replace for attach - Expose replace through VFIO APIs - Implement driver parameters for HWPT creation (nesting) Once review of this is complete I will keep it on a side branch and accumulate the following series when they are ready so we can have a stable base and make more incremental progress. When we have all the parts together to get a full implementation it can go to Linus. This is on github: https://github.com/jgunthorpe/linux/commits/iommufd_hwpt v7: - Rebase to v6.4-rc2, update to new signature of iommufd_get_ioas() v6: https://lore.kernel.org/r/0-v6-fdb604df649a+369-iommufd_alloc_jgg@nvidia.com - Go back to the v4 locking arragnment with now both the attach/detach igroup->locks inside the functions, Kevin says he needs this for a followup series. This still fixes the syzkaller bug - Fix two more error unwind locking bugs where iommufd_object_abort_and_destroy(hwpt) would deadlock or be mislocked. Make sure fail_nth will catch these mistakes - Add a patch allowing objects to have different abort than destroy function, it allows hwpt abort to require the caller to continue to hold the lock and enforces this with lockdep. v5: https://lore.kernel.org/r/0-v5-6716da355392+c5-iommufd_alloc_jgg@nvidia.com - Go back to the v3 version of the code, keep the comment changes from v4. Syzkaller says the group lock change in v4 didn't work. - Adjust the fail_nth test to cover the path syzkaller found. We need to have an ioas with a mapped page installed to inject a failure during domain attachment. v4: https://lore.kernel.org/r/0-v4-9cd79ad52ee8+13f5-iommufd_alloc_jgg@nvidia.c… - Refine comments and commit messages - Move the group lock into iommufd_hw_pagetable_attach() - Fix error unwind in iommufd_device_do_replace() v3: https://lore.kernel.org/r/0-v3-61d41fd9e13e+1f5-iommufd_alloc_jgg@nvidia.com - Refine comments and commit messages - Adjust the flow in iommufd_device_auto_get_domain() so pt_id is only set on success - Reject replace on non-attached devices - Add missing __reserved check for IOMMU_HWPT_ALLOC v2: https://lore.kernel.org/r/0-v2-51b9896e7862+8a8c-iommufd_alloc_jgg@nvidia.c… - Use WARN_ON for the igroup->group test and move that logic to a function iommufd_group_try_get() - Change igroup->devices to igroup->device list Replace will need to iterate over all attached idevs - Rename to iommufd_group_setup_msi() - New patch to export iommu_get_resv_regions() - New patch to use per-device reserved regions instead of per-group regions - Split out the reorganizing of iommufd_device_change_pt() from the replace patch - Replace uses the per-dev reserved regions - Use stdev_id in a few more places in the selftest - Fix error handling in IOMMU_HWPT_ALLOC - Clarify comments - Rebase on v6.3-rc1 v1: https://lore.kernel.org/all/0-v1-7612f88c19f5+2f21-iommufd_alloc_jgg@nvidia… Jason Gunthorpe (17): iommufd: Move isolated msi enforcement to iommufd_device_bind() iommufd: Add iommufd_group iommufd: Replace the hwpt->devices list with iommufd_group iommu: Export iommu_get_resv_regions() iommufd: Keep track of each device's reserved regions instead of groups iommufd: Use the iommufd_group to avoid duplicate MSI setup iommufd: Make sw_msi_start a group global iommufd: Move putting a hwpt to a helper function iommufd: Add enforced_cache_coherency to iommufd_hw_pagetable_alloc() iommufd: Allow a hwpt to be aborted after allocation iommufd: Fix locking around hwpt allocation iommufd: Reorganize iommufd_device_attach into iommufd_device_change_pt iommufd: Add iommufd_device_replace() iommufd: Make destroy_rwsem use a lock class per object type iommufd: Add IOMMU_HWPT_ALLOC iommufd/selftest: Return the real idev id from selftest mock_domain iommufd/selftest: Add a selftest for IOMMU_HWPT_ALLOC Nicolin Chen (2): iommu: Introduce a new iommu_group_replace_domain() API iommufd/selftest: Test iommufd_device_replace() drivers/iommu/iommu-priv.h | 10 + drivers/iommu/iommu.c | 41 +- drivers/iommu/iommufd/device.c | 553 +++++++++++++----- drivers/iommu/iommufd/hw_pagetable.c | 112 +++- drivers/iommu/iommufd/io_pagetable.c | 32 +- drivers/iommu/iommufd/iommufd_private.h | 52 +- drivers/iommu/iommufd/iommufd_test.h | 6 + drivers/iommu/iommufd/main.c | 24 +- drivers/iommu/iommufd/selftest.c | 40 ++ include/linux/iommufd.h | 1 + include/uapi/linux/iommufd.h | 26 + tools/testing/selftests/iommu/iommufd.c | 67 ++- .../selftests/iommu/iommufd_fail_nth.c | 67 ++- tools/testing/selftests/iommu/iommufd_utils.h | 63 +- 14 files changed, 868 insertions(+), 226 deletions(-) create mode 100644 drivers/iommu/iommu-priv.h base-commit: f1fcbaa18b28dec10281551dfe6ed3a3ed80e3d6 -- 2.40.1

1 year, 5 months

5
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ww_mutex.sh hangs since v5.16-rc1

by Li Zhijian

Hi Folks LKP/0Day found that ww_mutex.sh cannot complete since v5.16-rc1, but I'm pretty sorry that we failed to bisect the FBC, instead, the bisection pointed to a/below merge commit(91e1c99e17) finally. Due to this hang, other tests in the same group are also blocked in 0Day, we hope we can fix this hang ASAP. So if you have any idea about this, or need more debug information, feel free to let me know :) BTW, ww_mutex.sh was failed in v5.15 without hang, and looks it cannot reproduce on a vm. Our box: root@lkp-knm01 ~# lscpu Architecture: x86_64 CPU op-mode(s): 32-bit, 64-bit Byte Order: Little Endian Address sizes: 46 bits physical, 48 bits virtual CPU(s): 288 On-line CPU(s) list: 0-287 Thread(s) per core: 4 Core(s) per socket: 72 Socket(s): 1 NUMA node(s): 2 Vendor ID: GenuineIntel CPU family: 6 Model: 133 Model name: Intel(R) Xeon Phi(TM) CPU 7295 @ 1.50GHz Stepping: 0 CPU MHz: 1385.255 CPU max MHz: 1600.0000 CPU min MHz: 1000.0000 BogoMIPS: 2992.76 Virtualization: VT-x L1d cache: 32K L1i cache: 32K L2 cache: 1024K NUMA node0 CPU(s): 0-287 NUMA node1 CPU(s): Flags: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx pdpe1gb rdtscp lm constant_tsc arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc cpuid aperfmperf pni pclmulqdq dtes64 monitor ds_cpl vmx est tm2 ssse3 fma cx16 xtpr pdcm sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand lahf_lm abm 3dnowprefetch ring3mwait cpuid_fault epb pti tpr_shadow vnmi flexpriority ept vpid fsgsbase tsc_adjust bmi1 avx2 smep bmi2 erms avx512f rdseed adx avx512pf avx512er avx512cd xsaveopt dtherm ida arat pln pts avx512_vpopcntdq avx512_4vnniw avx512_4fmaps Below the call stack in v5.16-rc2 [ 1000.374954][ T2713] make: Leaving directory '/usr/src/perf_selftests-x86_64-rhel-8.3-kselftests-136057256686de39cc3a07c2e39ef6bc43003ff6/tools/testing/selftests/locking' [ 1000.375030][ T2713] [ 1000.428791][ T2713] 2021-11-22 22:21:27 make run_tests -C locking [ 1000.428864][ T2713] [ 1000.491043][ T2713] make: Entering directory '/usr/src/perf_selftests-x86_64-rhel-8.3-kselftests-136057256686de39cc3a07c2e39ef6bc43003ff6/tools/testing/selftests/locking' [ 1000.491121][ T2713] [ 1000.540807][ T2713] TAP version 13 [ 1000.540882][ T2713] [ 1000.576050][ T2713] 1..1 [ 1000.576282][ T2713] [ 1000.612980][ T2713] # selftests: locking: ww_mutex.sh [ 1000.613288][ T2713] [ 1495.201324][ T1577] INFO: task kworker/u576:16:1470 blocked for more than 491 seconds. [ 1495.220059][ T1577] Tainted: G B 5.16.0-rc2 #1 [ 1495.240902][ T1577] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 1495.265617][ T1577] task:kworker/u576:16 state:D stack: 0 pid: 1470 ppid: 2 flags:0x00004000 [ 1495.289054][ T1577] Workqueue: test-ww_mutex test_cycle_work [test_ww_mutex] [ 1495.310936][ T1577] Call Trace: [ 1495.327809][ T1577] <TASK> [ 1495.344735][ T1577] __schedule+0xdb0/0x25c0 [ 1495.362764][ T1577] ? io_schedule_timeout+0x180/0x180 [ 1495.382013][ T1577] ? lock_downgrade+0x680/0x680 [ 1495.400894][ T1577] ? do_raw_spin_lock+0x125/0x2c0 [ 1495.418866][ T1577] schedule+0xe4/0x280 [ 1495.435597][ T1577] schedule_preempt_disabled+0x18/0x40 [ 1495.454588][ T1577] __ww_mutex_lock+0x1248/0x34c0 [ 1495.476189][ T1577] ? test_cycle_work+0x1bb/0x500 [test_ww_mutex] [ 1495.497763][ T1577] ? mutex_lock_interruptible_nested+0x40/0x40 [ 1495.518959][ T1577] ? lock_downgrade+0x680/0x680 [ 1495.536861][ T1577] ? wait_for_completion_interruptible+0x340/0x340 [ 1495.556253][ T1577] ? ww_mutex_lock+0x3e/0x380 [ 1495.574003][ T1577] ww_mutex_lock+0x3e/0x380 [ 1495.591958][ T1577] test_cycle_work+0x1bb/0x500 [test_ww_mutex] [ 1495.612260][ T1577] ? stress_reorder_work+0xa00/0xa00 [test_ww_mutex] [ 1495.632857][ T1577] ? 0xffffffff81000000 [ 1495.649027][ T1577] ? rcu_read_lock_sched_held+0x5f/0x100 [ 1495.668211][ T1577] ? rcu_read_lock_bh_held+0xc0/0xc0 [ 1495.687010][ T1577] process_one_work+0x817/0x13c0 [ 1495.704991][ T1577] ? rcu_read_unlock+0x40/0x40 [ 1495.723024][ T1577] ? pwq_dec_nr_in_flight+0x280/0x280 [ 1495.740211][ T1577] ? rwlock_bug+0xc0/0xc0 [ 1495.758038][ T1577] worker_thread+0x8b/0xd80 [ 1495.775008][ T1577] ? process_one_work+0x13c0/0x13c0 [ 1495.793017][ T1577] kthread+0x3b9/0x4c0 [ 1495.810782][ T1577] ? set_kthread_struct+0x100/0x100 [ 1495.829988][ T1577] ret_from_fork+0x22/0x30 [ 1495.845811][ T1577] </TASK> [ 1495.859087][ T1577] INFO: task kworker/u576:36:1490 blocked for more than 492 seconds. [ 1495.879048][ T1577] Tainted: G B 5.16.0-rc2 #1 [ 1495.897879][ T1577] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 1495.919582][ T1577] task:kworker/u576:36 state:D stack: 0 pid: 1490 ppid: 2 flags:0x00004000 [ 1495.941865][ T1577] Workqueue: test-ww_mutex test_cycle_work [test_ww_mutex] [ 1495.959889][ T1577] Call Trace: [ 1495.974816][ T1577] <TASK> [ 1495.988759][ T1577] __schedule+0xdb0/0x25c0 [ 1495.988759][ T1577] __schedule+0xdb0/0x25c0 [ 1496.003849][ T1577] ? io_schedule_timeout+0x180/0x180 [ 1496.020839][ T1577] ? lock_downgrade+0x680/0x680 [ 1496.036854][ T1577] ? do_raw_spin_lock+0x125/0x2c0 [ 1496.051976][ T1577] schedule+0xe4/0x280 [ 1496.067780][ T1577] schedule_preempt_disabled+0x18/0x40 [ 1496.085004][ T1577] __ww_mutex_lock+0x1248/0x34c0 [ 1496.101895][ T1577] ? test_cycle_work+0x1bb/0x500 [test_ww_mutex] [ 1496.119889][ T1577] ? mutex_lock_interruptible_nested+0x40/0x40 [ 1496.137873][ T1577] ? lock_downgrade+0x680/0x680 [ 1496.152657][ T1577] ? wait_for_completion_interruptible+0x340/0x340 [ 1496.168773][ T1577] ? ww_mutex_lock+0x3e/0x380 [ 1496.184862][ T1577] ww_mutex_lock+0x3e/0x380 [ 1496.199979][ T1577] test_cycle_work+0x1bb/0x500 [test_ww_mutex] [ 1496.216277][ T1577] ? stress_reorder_work+0xa00/0xa00 [test_ww_mutex] [ 1496.234904][ T1577] ? 0xffffffff81000000 [ 1496.249856][ T1577] ? rcu_read_lock_sched_held+0x5f/0x100 [ 1496.265951][ T1577] ? rcu_read_lock_bh_held+0xc0/0xc0 [ 1496.282815][ T1577] process_one_work+0x817/0x13c0 [ 1496.299791][ T1577] ? rcu_read_unlock+0x40/0x40 [ 1496.314754][ T1577] ? pwq_dec_nr_in_flight+0x280/0x280 [ 1496.331779][ T1577] ? rwlock_bug+0xc0/0xc0 [ 1496.348007][ T1577] worker_thread+0x8b/0xd80 [ 1496.362905][ T1577] ? process_one_work+0x13c0/0x13c0 [ 1496.378975][ T1577] kthread+0x3b9/0x4c0 [ 1496.393866][ T1577] ? set_kthread_struct+0x100/0x100 [ 1496.408827][ T1577] ret_from_fork+0x22/0x30 [ 1496.423901][ T1577] </TASK> [ 1496.437994][ T1577] INFO: task kworker/u576:0:15113 blocked for more than 492 seconds. [ 1496.455862][ T1577] Tainted: G B 5.16.0-rc2 #1 [ 1496.473759][ T1577] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 1496.494808][ T1577] task:kworker/u576:0 state:D stack: 0 pid:15113 ppid: 2 flags:0x00004000 [ 1496.517000][ T1577] Workqueue: test-ww_mutex test_cycle_work [test_ww_mutex] [ 1496.537035][ T1577] Call Trace: [ 1496.551187][ T1577] <TASK> [ 1496.566405][ T1577] __schedule+0xdb0/0x25c0 [ 1496.582012][ T1577] ? io_schedule_timeout+0x180/0x180 [ 1496.598049][ T1577] ? lock_downgrade+0x680/0x680 [ 1496.615360][ T1577] ? do_raw_spin_lock+0x125/0x2c0 [ 1496.631835][ T1577] schedule+0xe4/0x280 [ 1496.645972][ T1577] schedule_preempt_disabled+0x18/0x40 [ 1496.663774][ T1577] __ww_mutex_lock+0x1248/0x34c0 [ 1496.681795][ T1577] ? test_cycle_work+0x1bb/0x500 [test_ww_mutex] [ 1496.698731][ T1577] ? mutex_lock_interruptible_nested+0x40/0x40 [ 1496.714996][ T1577] ? lock_downgrade+0x680/0x680 [ 1496.730888][ T1577] ? wait_for_completion_interruptible+0x340/0x340 [ 1496.747926][ T1577] ? ww_mutex_lock+0x3e/0x380 [ 1496.762482][ T1577] ww_mutex_lock+0x3e/0x380 [ 1496.778844][ T1577] test_cycle_work+0x1bb/0x500 [test_ww_mutex] And, we found that it occasionally hangs on v5.16-rc3 (1/3 runs), below is a good dmesg. [ 962.136756][ T2950] make: Entering directory '/usr/src/perf_selftests-x86_64-rhel-8.3-kselftests-d58071a8a76d779eedab38033ae4c821c30295a5/tools/testing/selftests/locking' [ 962.136831][ T2950]- [ 962.205036][ T2950] TAP version 13 [ 962.206003][ T2950]- [ 962.298458][ T2950] 1..1 [ 962.299657][ T2950]- [ 962.345588][ T2950] # selftests: locking: ww_mutex.sh [ 962.345657][ T2950]- [ 973.641869][T25509] All ww mutex selftests passed [ 973.773996][ T2950] # locking/ww_mutex: ok [ 973.774068][ T2950]- [ 973.774236][ T2960] # locking/ww_mutex: ok [ 973.802355][ T2960]- [ 973.829966][ T2950] ok 1 selftests: locking: ww_mutex.sh [ 973.834748][ T2950]- [ 973.838302][ T2960] ok 1 selftests: locking: ww_mutex.sh [ 973.899815][ T2960]- [ 973.921431][ T2950] make: Leaving directory '/usr/src/perf_selftests-x86_64-rhel-8.3-kselftests-d58071a8a76d779eedab38033ae4c821c30295a5/tools/testing/selftests/locking' [ 973.932312][ T2950]- [ 973.957345][ T2960] make: Leaving directory '/usr/src/perf_selftests-x86_64-rhel-8.3-kselftests-d58071a8a76d779eedab38033ae4c821c30295a5/tools/testing/selftests/locking' Thanks Zhijian@0Day

1 year, 5 months

3
3
0 0

[PATCH v22 0/5] Implement IOCTL to get and optionally clear info about PTEs

by Muhammad Usama Anjum

Changes in v22: - Interface change: - Replace [start start + len) with [start, end) - Return the ending address of the address walk in start Changes in v21: - Abort walk instead of returning error if WP is to be performed on partial hugetlb *Changes in v20* - Correct PAGE_IS_FILE and add PAGE_IS_PFNZERO *Changes in v19* - Minor changes and interface updates *Changes in v18* - Rebase on top of next-20230613 - Minor updates *Changes in v17* - Rebase on top of next-20230606 - Minor improvements in PAGEMAP_SCAN IOCTL patch *Changes in v16* - Fix a corner case - Add exclusive PM_SCAN_OP_WP back *Changes in v15* - Build fix (Add missed build fix in RESEND) *Changes in v14* - Fix build error caused by #ifdef added at last minute in some configs *Changes in v13* - Rebase on top of next-20230414 - Give-up on using uffd_wp_range() and write new helpers, flush tlb only once *Changes in v12* - Update and other memory types to UFFD_FEATURE_WP_ASYNC - Rebaase on top of next-20230406 - Review updates *Changes in v11* - Rebase on top of next-20230307 - Base patches on UFFD_FEATURE_WP_UNPOPULATED - Do a lot of cosmetic changes and review updates - Remove ENGAGE_WP + !GET operation as it can be performed with UFFDIO_WRITEPROTECT *Changes in v10* - Add specific condition to return error if hugetlb is used with wp async - Move changes in tools/include/uapi/linux/fs.h to separate patch - Add documentation *Changes in v9:* - Correct fault resolution for userfaultfd wp async - Fix build warnings and errors which were happening on some configs - Simplify pagemap ioctl's code *Changes in v8:* - Update uffd async wp implementation - Improve PAGEMAP_IOCTL implementation *Changes in v7:* - Add uffd wp async - Update the IOCTL to use uffd under the hood instead of soft-dirty flags *Motivation* The real motivation for adding PAGEMAP_SCAN IOCTL is to emulate Windows GetWriteWatch() syscall [1]. The GetWriteWatch{} retrieves the addresses of the pages that are written to in a region of virtual memory. This syscall is used in Windows applications and games etc. This syscall is being emulated in pretty slow manner in userspace. Our purpose is to enhance the kernel such that we translate it efficiently in a better way. Currently some out of tree hack patches are being used to efficiently emulate it in some kernels. We intend to replace those with these patches. So the whole gaming on Linux can effectively get benefit from this. It means there would be tons of users of this code. CRIU use case [2] was mentioned by Andrei and Danylo: > Use cases for migrating sparse VMAs are binaries sanitized with ASAN, > MSAN or TSAN [3]. All of these sanitizers produce sparse mappings of > shadow memory [4]. Being able to migrate such binaries allows to highly > reduce the amount of work needed to identify and fix post-migration > crashes, which happen constantly. Andrei's defines the following uses of this code: * it is more granular and allows us to track changed pages more effectively. The current interface can clear dirty bits for the entire process only. In addition, reading info about pages is a separate operation. It means we must freeze the process to read information about all its pages, reset dirty bits, only then we can start dumping pages. The information about pages becomes more and more outdated, while we are processing pages. The new interface solves both these downsides. First, it allows us to read pte bits and clear the soft-dirty bit atomically. It means that CRIU will not need to freeze processes to pre-dump their memory. Second, it clears soft-dirty bits for a specified region of memory. It means CRIU will have actual info about pages to the moment of dumping them. * The new interface has to be much faster because basic page filtering is happening in the kernel. With the old interface, we have to read pagemap for each page. *Implementation Evolution (Short Summary)* From the definition of GetWriteWatch(), we feel like kernel's soft-dirty feature can be used under the hood with some additions like: * reset soft-dirty flag for only a specific region of memory instead of clearing the flag for the entire process * get and clear soft-dirty flag for a specific region atomically So we decided to use ioctl on pagemap file to read or/and reset soft-dirty flag. But using soft-dirty flag, sometimes we get extra pages which weren't even written. They had become soft-dirty because of VMA merging and VM_SOFTDIRTY flag. This breaks the definition of GetWriteWatch(). We were able to by-pass this short coming by ignoring VM_SOFTDIRTY until David reported that mprotect etc messes up the soft-dirty flag while ignoring VM_SOFTDIRTY [5]. This wasn't happening until [6] got introduced. We discussed if we can revert these patches. But we could not reach to any conclusion. So at this point, I made couple of tries to solve this whole VM_SOFTDIRTY issue by correcting the soft-dirty implementation: * [7] Correct the bug fixed wrongly back in 2014. It had potential to cause regression. We left it behind. * [8] Keep a list of soft-dirty part of a VMA across splits and merges. I got the reply don't increase the size of the VMA by 8 bytes. At this point, we left soft-dirty considering it is too much delicate and userfaultfd [9] seemed like the only way forward. From there onward, we have been basing soft-dirty emulation on userfaultfd wp feature where kernel resolves the faults itself when WP_ASYNC feature is used. It was straight forward to add WP_ASYNC feature in userfautlfd. Now we get only those pages dirty or written-to which are really written in reality. (PS There is another WP_UNPOPULATED userfautfd feature is required which is needed to avoid pre-faulting memory before write-protecting [9].) All the different masks were added on the request of CRIU devs to create interface more generic and better. [1] https://learn.microsoft.com/en-us/windows/win32/api/memoryapi/nf-memoryapi-… [2] https://lore.kernel.org/all/20221014134802.1361436-1-mdanylo@google.com [3] https://github.com/google/sanitizers [4] https://github.com/google/sanitizers/wiki/AddressSanitizerAlgorithm#64-bit [5] https://lore.kernel.org/all/bfcae708-db21-04b4-0bbe-712badd03071@redhat.com [6] https://lore.kernel.org/all/20220725142048.30450-1-peterx@redhat.com/ [7] https://lore.kernel.org/all/20221122115007.2787017-1-usama.anjum@collabora.… [8] https://lore.kernel.org/all/20221220162606.1595355-1-usama.anjum@collabora.… [9] https://lore.kernel.org/all/20230306213925.617814-1-peterx@redhat.com [10] https://lore.kernel.org/all/20230125144529.1630917-1-mdanylo@google.com * Original Cover letter from v8* Hello, Note: Soft-dirty pages and pages which have been written-to are synonyms. As kernel already has soft-dirty feature inside which we have given up to use, we are using written-to terminology while using UFFD async WP under the hood. This IOCTL, PAGEMAP_SCAN on pagemap file can be used to get and/or clear the info about page table entries. The following operations are supported in this ioctl: - Get the information if the pages have been written-to (PAGE_IS_WRITTEN), file mapped (PAGE_IS_FILE), present (PAGE_IS_PRESENT) or swapped (PAGE_IS_SWAPPED). - Write-protect the pages (PAGEMAP_WP_ENGAGE) to start finding which pages have been written-to. - Find pages which have been written-to and write protect the pages (atomic PAGE_IS_WRITTEN + PAGEMAP_WP_ENGAGE) It is possible to find and clear soft-dirty pages entirely in userspace. But it isn't efficient: - The mprotect and SIGSEGV handler for bookkeeping - The userfaultfd wp (synchronous) with the handler for bookkeeping Some benchmarks can be seen here[1]. This series adds features that weren't present earlier: - There is no atomic get soft-dirty/Written-to status and clear present in the kernel. - The pages which have been written-to can not be found in accurate way. (Kernel's soft-dirty PTE bit + sof_dirty VMA bit shows more soft-dirty pages than there actually are.) Historically, soft-dirty PTE bit tracking has been used in the CRIU project. The procfs interface is enough for finding the soft-dirty bit status and clearing the soft-dirty bit of all the pages of a process. We have the use case where we need to track the soft-dirty PTE bit for only specific pages on-demand. We need this tracking and clear mechanism of a region of memory while the process is running to emulate the getWriteWatch() syscall of Windows. *(Moved to using UFFD instead of soft-dirtyi feature to find pages which have been written-to from v7 patch series)*: Stop using the soft-dirty flags for finding which pages have been written to. It is too delicate and wrong as it shows more soft-dirty pages than the actual soft-dirty pages. There is no interest in correcting it [2][3] as this is how the feature was written years ago. It shouldn't be updated to changed behaviour. Peter Xu has suggested using the async version of the UFFD WP [4] as it is based inherently on the PTEs. So in this patch series, I've added a new mode to the UFFD which is asynchronous version of the write protect. When this variant of the UFFD WP is used, the page faults are resolved automatically by the kernel. The pages which have been written-to can be found by reading pagemap file (!PM_UFFD_WP). This feature can be used successfully to find which pages have been written to from the time the pages were write protected. This works just like the soft-dirty flag without showing any extra pages which aren't soft-dirty in reality. The information related to pages if the page is file mapped, present and swapped is required for the CRIU project [5][6]. The addition of the required mask, any mask, excluded mask and return masks are also required for the CRIU project [5]. The IOCTL returns the addresses of the pages which match the specific masks. The page addresses are returned in struct page_region in a compact form. The max_pages is needed to support a use case where user only wants to get a specific number of pages. So there is no need to find all the pages of interest in the range when max_pages is specified. The IOCTL returns when the maximum number of the pages are found. The max_pages is optional. If max_pages is specified, it must be equal or greater than the vec_size. This restriction is needed to handle worse case when one page_region only contains info of one page and it cannot be compacted. This is needed to emulate the Windows getWriteWatch() syscall. The patch series include the detailed selftest which can be used as an example for the uffd async wp test and PAGEMAP_IOCTL. It shows the interface usages as well. [1] https://lore.kernel.org/lkml/54d4c322-cd6e-eefd-b161-2af2b56aae24@collabora… [2] https://lore.kernel.org/all/20221220162606.1595355-1-usama.anjum@collabora.… [3] https://lore.kernel.org/all/20221122115007.2787017-1-usama.anjum@collabora.… [4] https://lore.kernel.org/all/Y6Hc2d+7eTKs7AiH@x1n [5] https://lore.kernel.org/all/YyiDg79flhWoMDZB@gmail.com/ [6] https://lore.kernel.org/all/20221014134802.1361436-1-mdanylo@google.com/ Regards, Muhammad Usama Anjum Muhammad Usama Anjum (4): fs/proc/task_mmu: Implement IOCTL to get and optionally clear info about PTEs tools headers UAPI: Update linux/fs.h with the kernel sources mm/pagemap: add documentation of PAGEMAP_SCAN IOCTL selftests: mm: add pagemap ioctl tests Peter Xu (1): userfaultfd: UFFD_FEATURE_WP_ASYNC Documentation/admin-guide/mm/pagemap.rst | 58 + Documentation/admin-guide/mm/userfaultfd.rst | 35 + fs/proc/task_mmu.c | 565 +++++++ fs/userfaultfd.c | 26 +- include/linux/hugetlb.h | 1 + include/linux/userfaultfd_k.h | 21 +- include/uapi/linux/fs.h | 55 + include/uapi/linux/userfaultfd.h | 9 +- mm/hugetlb.c | 34 +- mm/memory.c | 27 +- tools/include/uapi/linux/fs.h | 55 + tools/testing/selftests/mm/.gitignore | 2 + tools/testing/selftests/mm/Makefile | 3 +- tools/testing/selftests/mm/config | 1 + tools/testing/selftests/mm/pagemap_ioctl.c | 1464 ++++++++++++++++++ tools/testing/selftests/mm/run_vmtests.sh | 4 + 16 files changed, 2336 insertions(+), 24 deletions(-) create mode 100644 tools/testing/selftests/mm/pagemap_ioctl.c mode change 100644 => 100755 tools/testing/selftests/mm/run_vmtests.sh -- 2.39.2

1 year, 5 months

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Linux-kselftest-mirror June 2023