February 2024 - Linux-kselftest-mirror

[PATCH v8 00/38] arm64/gcs: Provide support for GCS in userspace

by Mark Brown

The arm64 Guarded Control Stack (GCS) feature provides support for hardware protected stacks of return addresses, intended to provide hardening against return oriented programming (ROP) attacks and to make it easier to gather call stacks for applications such as profiling. When GCS is active a secondary stack called the Guarded Control Stack is maintained, protected with a memory attribute which means that it can only be written with specific GCS operations. The current GCS pointer can not be directly written to by userspace. When a BL is executed the value stored in LR is also pushed onto the GCS, and when a RET is executed the top of the GCS is popped and compared to LR with a fault being raised if the values do not match. GCS operations may only be performed on GCS pages, a data abort is generated if they are not. The combination of hardware enforcement and lack of extra instructions in the function entry and exit paths should result in something which has less overhead and is more difficult to attack than a purely software implementation like clang's shadow stacks. This series implements support for use of GCS by userspace, along with support for use of GCS within KVM guests. It does not enable use of GCS by either EL1 or EL2, this will be implemented separately. Executables are started without GCS and must use a prctl() to enable it, it is expected that this will be done very early in application execution by the dynamic linker or other startup code. For dynamic linking this will be done by checking that everything in the executable is marked as GCS compatible. x86 has an equivalent feature called shadow stacks, this series depends on the x86 patches for generic memory management support for the new guarded/shadow stack page type and shares APIs as much as possible. As there has been extensive discussion with the wider community around the ABI for shadow stacks I have as far as practical kept implementation decisions close to those for x86, anticipating that review would lead to similar conclusions in the absence of strong reasoning for divergence. The main divergence I am concious of is that x86 allows shadow stack to be enabled and disabled repeatedly, freeing the shadow stack for the thread whenever disabled, while this implementation keeps the GCS allocated after disable but refuses to reenable it. This is to avoid races with things actively walking the GCS during a disable, we do anticipate that some systems will wish to disable GCS at runtime but are not aware of any demand for subsequently reenabling it. x86 uses an arch_prctl() to manage enable and disable, since only x86 and S/390 use arch_prctl() a generic prctl() was proposed[1] as part of a patch set for the equivalent RISC-V Zicfiss feature which I initially adopted fairly directly but following review feedback has been revised quite a bit. We currently maintain the x86 pattern of implicitly allocating a shadow stack for threads started with shadow stack enabled, there has been some discussion of removing this support and requiring the use of clone3() with explicit allocation of shadow stacks instead. I have no strong feelings either way, implicit allocation is not really consistent with anything else we do and creates the potential for errors around thread exit but on the other hand it is existing ABI on x86 and minimises the changes needed in userspace code. There is an open issue with support for CRIU, on x86 this required the ability to set the GCS mode via ptrace. This series supports configuring mode bits other than enable/disable via ptrace but it needs to be confirmed if this is sufficient. The series depends on support for shadow stacks in clone3(), that series includes the addition of ARCH_HAS_USER_SHADOW_STACK. https://lore.kernel.org/r/20231120-clone3-shadow-stack-v3-0-a7b8ed3e2acc@ke… It also depends on the addition of more waitpid() flags to nolibc: https://lore.kernel.org/r/20231023-nolibc-waitpid-flags-v2-1-b09d096f091f@k… You can see a branch with the full set of dependencies against Linus' tree at: https://git.kernel.org/pub/scm/linux/kernel/git/broonie/misc.git arm64-gcs [1] https://lore.kernel.org/lkml/20230213045351.3945824-1-debug@rivosinc.com/ Signed-off-by: Mark Brown <broonie(a)kernel.org> --- Changes in v8: - Invalidate signal cap token on stack when consuming. - Typo and other trivial fixes. - Don't try to use process_vm_write() on GCS, it intentionally does not work. - Fix leak of thread GCSs. - Rebase onto latest clone3() series. - Link to v7: https://lore.kernel.org/r/20231122-arm64-gcs-v7-0-201c483bd775@kernel.org Changes in v7: - Rebase onto v6.7-rc2 via the clone3() patch series. - Change the token used to cap the stack during signal handling to be compatible with GCSPOPM. - Fix flags for new page types. - Fold in support for clone3(). - Replace copy_to_user_gcs() with put_user_gcs(). - Link to v6: https://lore.kernel.org/r/20231009-arm64-gcs-v6-0-78e55deaa4dd@kernel.org Changes in v6: - Rebase onto v6.6-rc3. - Add some more gcsb_dsync() barriers following spec clarifications. - Due to ongoing discussion around clone()/clone3() I've not updated anything there, the behaviour is the same as on previous versions. - Link to v5: https://lore.kernel.org/r/20230822-arm64-gcs-v5-0-9ef181dd6324@kernel.org Changes in v5: - Don't map any permissions for user GCSs, we always use EL0 accessors or use a separate mapping of the page. - Reduce the standard size of the GCS to RLIMIT_STACK/2. - Enforce a PAGE_SIZE alignment requirement on map_shadow_stack(). - Clarifications and fixes to documentation. - More tests. - Link to v4: https://lore.kernel.org/r/20230807-arm64-gcs-v4-0-68cfa37f9069@kernel.org Changes in v4: - Implement flags for map_shadow_stack() allowing the cap and end of stack marker to be enabled independently or not at all. - Relax size and alignment requirements for map_shadow_stack(). - Add more blurb explaining the advantages of hardware enforcement. - Link to v3: https://lore.kernel.org/r/20230731-arm64-gcs-v3-0-cddf9f980d98@kernel.org Changes in v3: - Rebase onto v6.5-rc4. - Add a GCS barrier on context switch. - Add a GCS stress test. - Link to v2: https://lore.kernel.org/r/20230724-arm64-gcs-v2-0-dc2c1d44c2eb@kernel.org Changes in v2: - Rebase onto v6.5-rc3. - Rework prctl() interface to allow each bit to be locked independently. - map_shadow_stack() now places the cap token based on the size requested by the caller not the actual space allocated. - Mode changes other than enable via ptrace are now supported. - Expand test coverage. - Various smaller fixes and adjustments. - Link to v1: https://lore.kernel.org/r/20230716-arm64-gcs-v1-0-bf567f93bba6@kernel.org --- Mark Brown (38): arm64/mm: Restructure arch_validate_flags() for extensibility prctl: arch-agnostic prctl for shadow stack mman: Add map_shadow_stack() flags arm64: Document boot requirements for Guarded Control Stacks arm64/gcs: Document the ABI for Guarded Control Stacks arm64/sysreg: Add definitions for architected GCS caps arm64/gcs: Add manual encodings of GCS instructions arm64/gcs: Provide put_user_gcs() arm64/cpufeature: Runtime detection of Guarded Control Stack (GCS) arm64/mm: Allocate PIE slots for EL0 guarded control stack mm: Define VM_SHADOW_STACK for arm64 when we support GCS arm64/mm: Map pages for guarded control stack KVM: arm64: Manage GCS registers for guests arm64/gcs: Allow GCS usage at EL0 and EL1 arm64/idreg: Add overrride for GCS arm64/hwcap: Add hwcap for GCS arm64/traps: Handle GCS exceptions arm64/mm: Handle GCS data aborts arm64/gcs: Context switch GCS state for EL0 arm64/gcs: Ensure that new threads have a GCS arm64/gcs: Implement shadow stack prctl() interface arm64/mm: Implement map_shadow_stack() arm64/signal: Set up and restore the GCS context for signal handlers arm64/signal: Expose GCS state in signal frames arm64/ptrace: Expose GCS via ptrace and core files arm64: Add Kconfig for Guarded Control Stack (GCS) kselftest/arm64: Verify the GCS hwcap kselftest/arm64: Add GCS as a detected feature in the signal tests kselftest/arm64: Add framework support for GCS to signal handling tests kselftest/arm64: Allow signals tests to specify an expected si_code kselftest/arm64: Always run signals tests with GCS enabled kselftest/arm64: Add very basic GCS test program kselftest/arm64: Add a GCS test program built with the system libc kselftest/arm64: Add test coverage for GCS mode locking selftests/arm64: Add GCS signal tests kselftest/arm64: Add a GCS stress test kselftest/arm64: Enable GCS for the FP stress tests kselftest: Provide shadow stack enable helpers for arm64 Documentation/admin-guide/kernel-parameters.txt | 6 + Documentation/arch/arm64/booting.rst | 22 + Documentation/arch/arm64/elf_hwcaps.rst | 3 + Documentation/arch/arm64/gcs.rst | 233 +++++++ Documentation/arch/arm64/index.rst | 1 + Documentation/filesystems/proc.rst | 2 +- arch/arm64/Kconfig | 20 + arch/arm64/include/asm/cpufeature.h | 6 + arch/arm64/include/asm/el2_setup.h | 17 + arch/arm64/include/asm/esr.h | 28 +- arch/arm64/include/asm/exception.h | 2 + arch/arm64/include/asm/gcs.h | 107 +++ arch/arm64/include/asm/hwcap.h | 1 + arch/arm64/include/asm/kvm_arm.h | 4 +- arch/arm64/include/asm/kvm_host.h | 12 + arch/arm64/include/asm/mman.h | 23 +- arch/arm64/include/asm/pgtable-prot.h | 14 +- arch/arm64/include/asm/processor.h | 7 + arch/arm64/include/asm/sysreg.h | 20 + arch/arm64/include/asm/uaccess.h | 40 ++ arch/arm64/include/uapi/asm/hwcap.h | 1 + arch/arm64/include/uapi/asm/ptrace.h | 8 + arch/arm64/include/uapi/asm/sigcontext.h | 9 + arch/arm64/kernel/cpufeature.c | 19 + arch/arm64/kernel/cpuinfo.c | 1 + arch/arm64/kernel/entry-common.c | 23 + arch/arm64/kernel/idreg-override.c | 2 + arch/arm64/kernel/process.c | 85 +++ arch/arm64/kernel/ptrace.c | 59 ++ arch/arm64/kernel/signal.c | 242 ++++++- arch/arm64/kernel/traps.c | 11 + arch/arm64/kvm/emulate-nested.c | 4 + arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h | 17 + arch/arm64/kvm/sys_regs.c | 22 + arch/arm64/mm/Makefile | 1 + arch/arm64/mm/fault.c | 79 ++- arch/arm64/mm/gcs.c | 300 +++++++++ arch/arm64/mm/mmap.c | 13 +- arch/arm64/tools/cpucaps | 1 + arch/x86/include/uapi/asm/mman.h | 3 - fs/proc/task_mmu.c | 3 + include/linux/mm.h | 16 +- include/uapi/asm-generic/mman.h | 4 + include/uapi/linux/elf.h | 1 + include/uapi/linux/prctl.h | 22 + kernel/sys.c | 30 + tools/testing/selftests/arm64/Makefile | 2 +- tools/testing/selftests/arm64/abi/hwcap.c | 19 + tools/testing/selftests/arm64/fp/assembler.h | 15 + tools/testing/selftests/arm64/fp/fpsimd-test.S | 2 + tools/testing/selftests/arm64/fp/sve-test.S | 2 + tools/testing/selftests/arm64/fp/za-test.S | 2 + tools/testing/selftests/arm64/fp/zt-test.S | 2 + tools/testing/selftests/arm64/gcs/.gitignore | 5 + tools/testing/selftests/arm64/gcs/Makefile | 24 + tools/testing/selftests/arm64/gcs/asm-offsets.h | 0 tools/testing/selftests/arm64/gcs/basic-gcs.c | 428 ++++++++++++ tools/testing/selftests/arm64/gcs/gcs-locking.c | 200 ++++++ .../selftests/arm64/gcs/gcs-stress-thread.S | 311 +++++++++ tools/testing/selftests/arm64/gcs/gcs-stress.c | 532 +++++++++++++++ tools/testing/selftests/arm64/gcs/gcs-util.h | 100 +++ tools/testing/selftests/arm64/gcs/libc-gcs.c | 736 +++++++++++++++++++++ tools/testing/selftests/arm64/signal/.gitignore | 1 + .../testing/selftests/arm64/signal/test_signals.c | 17 +- .../testing/selftests/arm64/signal/test_signals.h | 6 + .../selftests/arm64/signal/test_signals_utils.c | 32 +- .../selftests/arm64/signal/test_signals_utils.h | 39 ++ .../arm64/signal/testcases/gcs_exception_fault.c | 62 ++ .../selftests/arm64/signal/testcases/gcs_frame.c | 88 +++ .../arm64/signal/testcases/gcs_write_fault.c | 67 ++ .../selftests/arm64/signal/testcases/testcases.c | 7 + .../selftests/arm64/signal/testcases/testcases.h | 1 + tools/testing/selftests/ksft_shstk.h | 37 ++ 73 files changed, 4241 insertions(+), 40 deletions(-) --- base-commit: 50abefbf1bc07f5c4e403fd28f71dcee855100f7 change-id: 20230303-arm64-gcs-e311ab0d8729 Best regards, -- Mark Brown <broonie(a)kernel.org>

1 year, 1 month

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[PATCH v2 00/12] conform tests to TAP format output

by Muhammad Usama Anjum

Changes since v1: - Rebased the series on top of next-20240202 Muhammad Usama Anjum (12): selftests/mm: map_fixed_noreplace: conform test to TAP format output selftests/mm: map_hugetlb: conform test to TAP format output selftests/mm: map_populate: conform test to TAP format output selftests/mm: mlock-random-test: conform test to TAP format output selftests/mm: mlock2-tests: conform test to TAP format output selftests/mm: mrelease_test: conform test to TAP format output selftests/mm: mremap_dontunmap: conform test to TAP format output selftests/mm: split_huge_page_test: conform test to TAP format output selftests/mm: thp_settings: conform to TAP format output selftests/mm: thuge-gen: conform to TAP format output selftests/mm: transhuge-stress: conform to TAP format output selftests/mm: virtual_address_range: conform to TAP format output tools/testing/selftests/mm/khugepaged.c | 3 +- .../selftests/mm/map_fixed_noreplace.c | 96 ++---- tools/testing/selftests/mm/map_hugetlb.c | 42 ++- tools/testing/selftests/mm/map_populate.c | 37 ++- .../testing/selftests/mm/mlock-random-test.c | 136 ++++----- tools/testing/selftests/mm/mlock2-tests.c | 282 +++++++----------- tools/testing/selftests/mm/mlock2.h | 11 +- tools/testing/selftests/mm/mrelease_test.c | 80 ++--- tools/testing/selftests/mm/mremap_dontunmap.c | 32 +- .../selftests/mm/split_huge_page_test.c | 161 +++++----- tools/testing/selftests/mm/thp_settings.c | 123 +++----- tools/testing/selftests/mm/thp_settings.h | 4 +- tools/testing/selftests/mm/thuge-gen.c | 147 ++++----- tools/testing/selftests/mm/transhuge-stress.c | 36 ++- .../selftests/mm/virtual_address_range.c | 44 +-- tools/testing/selftests/mm/vm_util.c | 6 +- 16 files changed, 537 insertions(+), 703 deletions(-) -- 2.42.0

1 year, 1 month

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[PATCH v3 0/5] selftests/mm: Improve run_vmtests.sh

by Muhammad Usama Anjum

In this series, I'm trying to add 3 missing tests to vm_runtests.sh which is used to run all the tests in mm suite. These tests weren't running by CIs. While enabling them and through review feedback, I've fixed some problems in tests as well. I've found more flakiness in more tests which I'll be fixing with future patches. hugetlb-read-hwpoison test is being added where it can only run with newly added "-d" (destructive) flag only. Not sure why it is failing again. So once it become stable, we can think of moving it to default set of tests if it doesn't have any side-effect to them. Cc: Ryan Roberts <ryan.roberts(a)arm.com> Cc: Andrew Morton <akpm(a)linux-foundation.org> --- Changes in v3: - Add cover letter - Fix flakiness in tests found during enablement - Move additional tests down in the file - Add "-d" option which poisons the pages and aren't being useable after the test v2: https://lore.kernel.org/all/20240123073615.920324-1-usama.anjum@collabora.c… Muhammad Usama Anjum (5): selftests/mm: hugetlb_reparenting_test: do not unmount selftests/mm: run_vmtests: remove sudo and conform to tap selftests/mm: save and restore nr_hugepages value selftests/mm: protection_keys: save/restore nr_hugepages settings selftests/mm: run_vmtests.sh: add missing tests tools/testing/selftests/mm/Makefile | 5 +++ .../selftests/mm/charge_reserved_hugetlb.sh | 4 +++ .../selftests/mm/hugetlb_reparenting_test.sh | 9 +++-- tools/testing/selftests/mm/on-fault-limit.c | 36 +++++++++---------- tools/testing/selftests/mm/protection_keys.c | 34 ++++++++++++++++++ tools/testing/selftests/mm/run_vmtests.sh | 10 +++++- 6 files changed, 76 insertions(+), 22 deletions(-) -- 2.42.0

1 year, 1 month

3
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[PATCH v7 0/4] KVM: selftests: Add LoongArch support

by Bibo Mao

This patchset adds KVM selftests for LoongArch system, currently only some common test cases are supported and pass to run. These testcase are listed as following: demand_paging_test dirty_log_perf_test dirty_log_test guest_print_test hardware_disable_test kvm_binary_stats_test kvm_create_max_vcpus kvm_page_table_test memslot_modification_stress_test memslot_perf_test set_memory_region_test This patchset originally is posted from zhaotianrui, I continue to work on his efforts. --- Changes in v7: 1. Refine code to add LoongArch support in test case set_memory_region_test. Changes in v6: 1. Refresh the patch based on latest kernel 6.8-rc1, add LoongArch support about testcase set_memory_region_test. 2. Add hardware_disable_test test case. 3. Drop modification about macro DEFAULT_GUEST_TEST_MEM, it is problem of LoongArch binutils, this issue is raised to LoongArch binutils owners. Changes in v5: 1. In LoongArch kvm self tests, the DEFAULT_GUEST_TEST_MEM could be 0x130000000, it is different from the default value in memstress.h. So we Move the definition of DEFAULT_GUEST_TEST_MEM into LoongArch ucall.h, and add 'ifndef' condition for DEFAULT_GUEST_TEST_MEM in memstress.h. Changes in v4: 1. Remove the based-on flag, as the LoongArch KVM patch series have been accepted by Linux kernel, so this can be applied directly in kernel. Changes in v3: 1. Improve implementation of LoongArch VM page walk. 2. Add exception handler for LoongArch. 3. Add dirty_log_test, dirty_log_perf_test, guest_print_test test cases for LoongArch. 4. Add __ASSEMBLER__ macro to distinguish asm file and c file. 5. Move ucall_arch_do_ucall to the header file and make it as static inline to avoid function calls. 6. Change the DEFAULT_GUEST_TEST_MEM base addr for LoongArch. Changes in v2: 1. We should use ".balign 4096" to align the assemble code with 4K in exception.S instead of "align 12". 2. LoongArch only supports 3 or 4 levels page tables, so we remove the hanlders for 2-levels page table. 3. Remove the DEFAULT_LOONGARCH_GUEST_STACK_VADDR_MIN and use the common DEFAULT_GUEST_STACK_VADDR_MIN to allocate stack memory in guest. 4. Reorganize the test cases supported by LoongArch. 5. Fix some code comments. 6. Add kvm_binary_stats_test test case into LoongArch KVM selftests. --- Tianrui Zhao (4): KVM: selftests: Add KVM selftests header files for LoongArch KVM: selftests: Add core KVM selftests support for LoongArch KVM: selftests: Add ucall test support for LoongArch KVM: selftests: Add test cases for LoongArch tools/testing/selftests/kvm/Makefile | 16 + .../selftests/kvm/include/kvm_util_base.h | 5 + .../kvm/include/loongarch/processor.h | 133 +++++++ .../selftests/kvm/include/loongarch/ucall.h | 20 ++ .../selftests/kvm/lib/loongarch/exception.S | 59 ++++ .../selftests/kvm/lib/loongarch/processor.c | 332 ++++++++++++++++++ .../selftests/kvm/lib/loongarch/ucall.c | 38 ++ .../selftests/kvm/set_memory_region_test.c | 2 +- 8 files changed, 604 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/kvm/include/loongarch/processor.h create mode 100644 tools/testing/selftests/kvm/include/loongarch/ucall.h create mode 100644 tools/testing/selftests/kvm/lib/loongarch/exception.S create mode 100644 tools/testing/selftests/kvm/lib/loongarch/processor.c create mode 100644 tools/testing/selftests/kvm/lib/loongarch/ucall.c base-commit: 6764c317b6bb91bd806ef79adf6d9c0e428b191e -- 2.39.3

1 year, 1 month

2
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[PATCH] tools/testing/selftests/bpf/test_tc_tunnel.sh: Prevent client connect before server bind

by Alessandro Carminati (Red Hat)

In some systems, the netcat server can incur in delay to start listening. When this happens, the test can randomly fail in various points. This is an example error message: # ip gre none gso # encap 192.168.1.1 to 192.168.1.2, type gre, mac none len 2000 # test basic connectivity # Ncat: Connection refused. Signed-off-by: Alessandro Carminati (Red Hat) <alessandro.carminati(a)gmail.com> --- tools/testing/selftests/bpf/test_tc_tunnel.sh | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/bpf/test_tc_tunnel.sh b/tools/testing/selftests/bpf/test_tc_tunnel.sh index 910044f08908..01c0f4b1a8c2 100755 --- a/tools/testing/selftests/bpf/test_tc_tunnel.sh +++ b/tools/testing/selftests/bpf/test_tc_tunnel.sh @@ -72,7 +72,6 @@ cleanup() { server_listen() { ip netns exec "${ns2}" nc "${netcat_opt}" -l "${port}" > "${outfile}" & server_pid=$! - sleep 0.2 } client_connect() { @@ -93,6 +92,22 @@ verify_data() { fi } +wait_for_port() { + local digits=8 + local port2check=$(printf ":%04X" $1) + local prot=$([ "$2" == "-6" ] && echo 6 && digits=32) + + for i in $(seq 20); do + if ip netns exec "${ns2}" cat /proc/net/tcp${prot} | \ + sed -r 's/^[ \t]+[0-9]+: ([0-9A-F]{'${digits}'}:[0-9A-F]{4}) .*$/\1/' | \ + grep -q "${port2check}"; then + return 0 + fi + sleep 0.1 + done + return 1 +} + set -e # no arguments: automated test, run all @@ -193,6 +208,7 @@ setup # basic communication works echo "test basic connectivity" server_listen +wait_for_port ${port} ${netcat_opt} client_connect verify_data @@ -204,6 +220,7 @@ ip netns exec "${ns1}" tc filter add dev veth1 egress \ section "encap_${tuntype}_${mac}" echo "test bpf encap without decap (expect failure)" server_listen +wait_for_port ${port} ${netcat_opt} ! client_connect if [[ "$tuntype" =~ "udp" ]]; then -- 2.34.1

1 year, 1 month

3
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Re: [PATCH 2/7] of: Create of_root if no dtb provided by firmware

by Saurabh Singh Sengar

On Fri, Feb 16, 2024 at 05:05:51PM -0800, Frank Rowand wrote: > When enabling CONFIG_OF on a platform where 'of_root' is not populated > by firmware, we end up without a root node. In order to apply overlays > and create subnodes of the root node, we need one. Create this root node > by unflattening an empty builtin dtb. > > If firmware provides a flattened device tree (FDT) then the FDT is > unflattened via setup_arch(). Otherwise, the call to > unflatten(_and_copy)?_device_tree() will create an empty root node. > > We make of_have_populated_dt() return true only if the DTB was loaded by > firmware so that existing callers don't change behavior after this > patch. The call in the of platform code is removed because it prevents > overlays from creating platform devices when the empty root node is > used. > > [sboyd(a)kernel.org: Update of_have_populated_dt() to treat this empty dtb > as not populated. Drop setup_of() initcall] > > Signed-off-by: Frank Rowand <frowand.list(a)gmail.com> > Link: https://lore.kernel.org/r/20230317053415.2254616-2-frowand.list@gmail.com > Cc: Rob Herring <robh+dt(a)kernel.org> > Signed-off-by: Stephen Boyd <sboyd(a)kernel.org> > --- > drivers/of/Kconfig | 5 ++--- > drivers/of/Makefile | 2 +- > drivers/of/empty_root.dts | 6 ++++++ > drivers/of/fdt.c | 32 +++++++++++++++++++++++++++++++- > drivers/of/platform.c | 3 --- > include/linux/of.h | 25 +++++++++++++++---------- > 6 files changed, 55 insertions(+), 18 deletions(-) > create mode 100644 drivers/of/empty_root.dts > > diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig > index da9826accb1b..d738fbad9c36 100644 > --- a/drivers/of/Kconfig > +++ b/drivers/of/Kconfig > @@ -14,9 +14,8 @@ if OF > > config OF_UNITTEST > bool "Device Tree runtime unit tests" > - depends on !SPARC > + depends on OF_EARLY_FLATTREE > select IRQ_DOMAIN > - select OF_EARLY_FLATTREE > select OF_RESOLVE > help > This option builds in test cases for the device tree infrastructure > @@ -54,7 +53,7 @@ config OF_FLATTREE > select CRC32 > > config OF_EARLY_FLATTREE > - bool > + def_bool OF && !(SPARC || ALPHA || HEXAGON || M68K || PARISC || S390) > select DMA_DECLARE_COHERENT if HAS_DMA && HAS_IOMEM > select OF_FLATTREE > > diff --git a/drivers/of/Makefile b/drivers/of/Makefile > index eff624854575..df305348d1cb 100644 > --- a/drivers/of/Makefile > +++ b/drivers/of/Makefile > @@ -2,7 +2,7 @@ > obj-y = base.o cpu.o device.o module.o platform.o property.o > obj-$(CONFIG_OF_KOBJ) += kobj.o > obj-$(CONFIG_OF_DYNAMIC) += dynamic.o > -obj-$(CONFIG_OF_FLATTREE) += fdt.o > +obj-$(CONFIG_OF_FLATTREE) += fdt.o empty_root.dtb.o > obj-$(CONFIG_OF_EARLY_FLATTREE) += fdt_address.o > obj-$(CONFIG_OF_PROMTREE) += pdt.o > obj-$(CONFIG_OF_ADDRESS) += address.o > diff --git a/drivers/of/empty_root.dts b/drivers/of/empty_root.dts > new file mode 100644 > index 000000000000..cf9e97a60f48 > --- /dev/null > +++ b/drivers/of/empty_root.dts > @@ -0,0 +1,6 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/dts-v1/; > + > +/ { > + > +}; > diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c > index dfeba8b8ce94..e5a385285149 100644 > --- a/drivers/of/fdt.c > +++ b/drivers/of/fdt.c > @@ -8,6 +8,7 @@ > > #define pr_fmt(fmt) "OF: fdt: " fmt > > +#include <linux/acpi.h> > #include <linux/crash_dump.h> > #include <linux/crc32.h> > #include <linux/kernel.h> > @@ -32,6 +33,13 @@ > > #include "of_private.h" > > +/* > + * __dtb_empty_root_begin[] and __dtb_empty_root_end[] magically created by > + * cmd_dt_S_dtb in scripts/Makefile.lib > + */ > +extern uint8_t __dtb_empty_root_begin[]; > +extern uint8_t __dtb_empty_root_end[]; > + > /* > * of_fdt_limit_memory - limit the number of regions in the /memory node > * @limit: maximum entries > @@ -1343,7 +1351,29 @@ static void *__init copy_device_tree(void *fdt) > */ > void __init unflatten_device_tree(void) > { > - __unflatten_device_tree(initial_boot_params, NULL, &of_root, > + void *fdt = initial_boot_params; > + > + /* Don't use the bootloader provided DTB if ACPI is enabled */ > + if (!acpi_disabled) > + fdt = NULL; > + > + /* > + * Populate an empty root node when ACPI is enabled or bootloader > + * doesn't provide one. > + */ > + if (!fdt) { > + fdt = (void *) __dtb_empty_root_begin; > + /* fdt_totalsize() will be used for copy size */ > + if (fdt_totalsize(fdt) > > + __dtb_empty_root_end - __dtb_empty_root_begin) { > + pr_err("invalid size in dtb_empty_root\n"); > + return; > + } > + of_fdt_crc32 = crc32_be(~0, fdt, fdt_totalsize(fdt)); > + fdt = copy_device_tree(fdt); > + } > + > + __unflatten_device_tree(fdt, NULL, &of_root, > early_init_dt_alloc_memory_arch, false); > > /* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */ > diff --git a/drivers/of/platform.c b/drivers/of/platform.c > index b7708a06dc78..39c0ceee3e95 100644 > --- a/drivers/of/platform.c > +++ b/drivers/of/platform.c > @@ -510,9 +510,6 @@ static int __init of_platform_default_populate_init(void) > > device_links_supplier_sync_state_pause(); > > - if (!of_have_populated_dt()) > - return -ENODEV; > - > if (IS_ENABLED(CONFIG_PPC)) { > struct device_node *boot_display = NULL; > struct platform_device *dev; > diff --git a/include/linux/of.h b/include/linux/of.h > index 331e05918f11..168357486260 100644 > --- a/include/linux/of.h > +++ b/include/linux/of.h > @@ -180,11 +180,6 @@ static inline bool is_of_node(const struct fwnode_handle *fwnode) > &__of_fwnode_handle_node->fwnode : NULL; \ > }) > > -static inline bool of_have_populated_dt(void) > -{ > - return of_root != NULL; > -} > - > static inline bool of_node_is_root(const struct device_node *node) > { > return node && (node->parent == NULL); > @@ -557,11 +552,6 @@ static inline struct device_node *of_find_node_with_property( > > #define of_fwnode_handle(node) NULL > > -static inline bool of_have_populated_dt(void) > -{ > - return false; > -} > - > static inline struct device_node *of_get_compatible_child(const struct device_node *parent, > const char *compatible) > { > @@ -1645,6 +1635,21 @@ static inline bool of_device_is_system_power_controller(const struct device_node > return of_property_read_bool(np, "system-power-controller"); > } > > +/** > + * of_have_populated_dt() - Has DT been populated by bootloader > + * > + * Return: True if a DTB has been populated by the bootloader and it isn't the > + * empty builtin one. False otherwise. > + */ > +static inline bool of_have_populated_dt(void) > +{ > +#ifdef CONFIG_OF > + return of_property_present(of_root, "compatible"); This adds the strict check for compatible which makes compatible to be mandatory for root nodes. So far, DeviceTree without compatible property in root nodes can work. Do we want to make this documented somewhere ? - Saurabh > +#else > + return false; > +#endif > +} > + > /* > * Overlay support > */ > -- > 2.34.1

1 year, 1 month

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[PATCH v2 00/31] NT synchronization primitive driver

by Elizabeth Figura

This patch series introduces a new char misc driver, /dev/ntsync, which is used to implement Windows NT synchronization primitives. This was previously submitted as an RFC [1]. Since there were no major changes requested to the last RFC revision, I've stripped the RFC prefix. [1] https://lore.kernel.org/lkml/20240131021356.10322-1-zfigura@codeweavers.com/ == Background == The Wine project emulates the Windows API in user space. One particular part of that API, namely the NT synchronization primitives, have historically been implemented via RPC to a dedicated "kernel" process. However, more recent applications use these APIs more strenuously, and the overhead of RPC has become a bottleneck. The NT synchronization APIs are too complex to implement on top of existing primitives without sacrificing correctness. Certain operations, such as NtPulseEvent() or the "wait-for-all" mode of NtWaitForMultipleObjects(), require direct control over the underlying wait queue, and implementing a wait queue sufficiently robust for Wine in user space is not possible. This proposed driver, therefore, implements the problematic interfaces directly in the Linux kernel. This driver was presented at Linux Plumbers Conference 2023. For those further interested in the history of synchronization in Wine and past attempts to solve this problem in user space, a recording of the presentation can be viewed here: https://www.youtube.com/watch?v=NjU4nyWyhU8 == Performance == The gain in performance varies wildly depending on the application in question and the user's hardware. For some games NT synchronization is not a bottleneck and no change can be observed, but for others frame rate improvements of 50 to 150 percent are not atypical. The following table lists frame rate measurements from a variety of games on a variety of hardware, taken by users Dmitry Skvortsov, FuzzyQuils, OnMars, and myself: Game Upstream ntsync improvement =========================================================================== Anger Foot 69 99 43% Call of Juarez 99.8 224.1 125% Dirt 3 110.6 860.7 678% Forza Horizon 5 108 160 48% Lara Croft: Temple of Osiris 141 326 131% Metro 2033 164.4 199.2 21% Resident Evil 2 26 77 196% The Crew 26 51 96% Tiny Tina's Wonderlands 130 360 177% Total War Saga: Troy 109 146 34% =========================================================================== == Patches == The intended semantics of the patches are broadly intended to match those of the corresponding Windows functions. For those not already familiar with the Windows functions (or their undocumented behaviour), patch 31/31 provides a detailed specification, and individual patches also include a brief description of the API they are implementing. The patches making use of this driver in Wine can be retrieved or browsed here: https://repo.or.cz/wine/zf.git/shortlog/refs/heads/ntsync5 == Implementation == Some aspects of the implementation may deserve particular comment: * In the interest of performance, each object is governed only by a single spinlock. However, NTSYNC_IOC_WAIT_ALL requires that the state of multiple objects be changed as a single atomic operation. In order to achieve this, we first take a device-wide lock ("wait_all_lock") any time we are going to lock more than one object at a time. The maximum number of objects that can be used in a vectored wait, and therefore the maximum that can be locked simultaneously, is 64. This number is NT's own limit. The acquisition of multiple spinlocks will degrade performance. This is a conscious choice, however. Wait-for-all is known to be a very rare operation in practice, especially with counts that approach the maximum, and it is the intent of the ntsync driver to optimize wait-for-any at the expense of wait-for-all as much as possible. * NT mutexes are tied to their threads on an OS level, and the kernel includes builtin support for "robust" mutexes. In order to keep the ntsync driver self-contained and avoid touching more code than necessary, it does not hook into task exit nor use pids. Instead, the user space emulator is expected to manage thread IDs and pass them as an argument to any relevant functions; this is the "owner" field of ntsync_wait_args and ntsync_mutex_args. When the emulator detects that a thread dies, it should therefore call NTSYNC_IOC_MUTEX_KILL on any open mutexes. * ntsync is module-capable mostly because there was nothing preventing it, and because it aided development. It is not a hard requirement, though. == Previous versions == Changes from v1: * Fix a broken rebase that stole part of the Kconfig documentation from the neighbouring entry, per Randy Dunlap. * Add my email address to copyright and MODULE_AUTHOR lines, per Randy Dunlap. * Document the reference counting behaviour more clearly, per Greg Kroah-Hartman. * Hopefully submit all the patches this time the right way. * Link to v1: https://lore.kernel.org/lkml/20240214233645.9273-1-zfigura@codeweavers.com/ * Link to RFC v2: https://lore.kernel.org/lkml/20240131021356.10322-1-zfigura@codeweavers.com/ * Link to RFC v1: https://lore.kernel.org/lkml/20240124004028.16826-1-zfigura@codeweavers.com/ Elizabeth Figura (31): ntsync: Introduce the ntsync driver and character device. ntsync: Introduce NTSYNC_IOC_CREATE_SEM. ntsync: Introduce NTSYNC_IOC_SEM_POST. ntsync: Introduce NTSYNC_IOC_WAIT_ANY. ntsync: Introduce NTSYNC_IOC_WAIT_ALL. ntsync: Introduce NTSYNC_IOC_CREATE_MUTEX. ntsync: Introduce NTSYNC_IOC_MUTEX_UNLOCK. ntsync: Introduce NTSYNC_IOC_MUTEX_KILL. ntsync: Introduce NTSYNC_IOC_CREATE_EVENT. ntsync: Introduce NTSYNC_IOC_EVENT_SET. ntsync: Introduce NTSYNC_IOC_EVENT_RESET. ntsync: Introduce NTSYNC_IOC_EVENT_PULSE. ntsync: Introduce NTSYNC_IOC_SEM_READ. ntsync: Introduce NTSYNC_IOC_MUTEX_READ. ntsync: Introduce NTSYNC_IOC_EVENT_READ. ntsync: Introduce alertable waits. ntsync: Allow waits to use the REALTIME clock. selftests: ntsync: Add some tests for semaphore state. selftests: ntsync: Add some tests for mutex state. selftests: ntsync: Add some tests for NTSYNC_IOC_WAIT_ANY. selftests: ntsync: Add some tests for NTSYNC_IOC_WAIT_ALL. selftests: ntsync: Add some tests for wakeup signaling with WINESYNC_IOC_WAIT_ANY. selftests: ntsync: Add some tests for wakeup signaling with WINESYNC_IOC_WAIT_ALL. selftests: ntsync: Add some tests for manual-reset event state. selftests: ntsync: Add some tests for auto-reset event state. selftests: ntsync: Add some tests for wakeup signaling with events. selftests: ntsync: Add tests for alertable waits. selftests: ntsync: Add some tests for wakeup signaling via alerts. selftests: ntsync: Add a stress test for contended waits. maintainers: Add an entry for ntsync. docs: ntsync: Add documentation for the ntsync uAPI. Elizabeth Figura (31): ntsync: Introduce the ntsync driver and character device. ntsync: Introduce NTSYNC_IOC_CREATE_SEM. ntsync: Introduce NTSYNC_IOC_SEM_POST. ntsync: Introduce NTSYNC_IOC_WAIT_ANY. ntsync: Introduce NTSYNC_IOC_WAIT_ALL. ntsync: Introduce NTSYNC_IOC_CREATE_MUTEX. ntsync: Introduce NTSYNC_IOC_MUTEX_UNLOCK. ntsync: Introduce NTSYNC_IOC_MUTEX_KILL. ntsync: Introduce NTSYNC_IOC_CREATE_EVENT. ntsync: Introduce NTSYNC_IOC_EVENT_SET. ntsync: Introduce NTSYNC_IOC_EVENT_RESET. ntsync: Introduce NTSYNC_IOC_EVENT_PULSE. ntsync: Introduce NTSYNC_IOC_SEM_READ. ntsync: Introduce NTSYNC_IOC_MUTEX_READ. ntsync: Introduce NTSYNC_IOC_EVENT_READ. ntsync: Introduce alertable waits. ntsync: Allow waits to use the REALTIME clock. selftests: ntsync: Add some tests for semaphore state. selftests: ntsync: Add some tests for mutex state. selftests: ntsync: Add some tests for NTSYNC_IOC_WAIT_ANY. selftests: ntsync: Add some tests for NTSYNC_IOC_WAIT_ALL. selftests: ntsync: Add some tests for wakeup signaling with WINESYNC_IOC_WAIT_ANY. selftests: ntsync: Add some tests for wakeup signaling with WINESYNC_IOC_WAIT_ALL. selftests: ntsync: Add some tests for manual-reset event state. selftests: ntsync: Add some tests for auto-reset event state. selftests: ntsync: Add some tests for wakeup signaling with events. selftests: ntsync: Add tests for alertable waits. selftests: ntsync: Add some tests for wakeup signaling via alerts. selftests: ntsync: Add a stress test for contended waits. maintainers: Add an entry for ntsync. docs: ntsync: Add documentation for the ntsync uAPI. Documentation/userspace-api/index.rst | 1 + .../userspace-api/ioctl/ioctl-number.rst | 2 + Documentation/userspace-api/ntsync.rst | 399 +++++ MAINTAINERS | 9 + drivers/misc/Kconfig | 11 + drivers/misc/Makefile | 1 + drivers/misc/ntsync.c | 1159 ++++++++++++++ include/uapi/linux/ntsync.h | 62 + tools/testing/selftests/Makefile | 1 + .../testing/selftests/drivers/ntsync/Makefile | 8 + tools/testing/selftests/drivers/ntsync/config | 1 + .../testing/selftests/drivers/ntsync/ntsync.c | 1407 +++++++++++++++++ 12 files changed, 3061 insertions(+) create mode 100644 Documentation/userspace-api/ntsync.rst create mode 100644 drivers/misc/ntsync.c create mode 100644 include/uapi/linux/ntsync.h create mode 100644 tools/testing/selftests/drivers/ntsync/Makefile create mode 100644 tools/testing/selftests/drivers/ntsync/config create mode 100644 tools/testing/selftests/drivers/ntsync/ntsync.c base-commit: 8d11c6d9b14f7a87f65529cb33edc5fed846ed9d -- 2.43.0

1 year, 1 month

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[PATCH v4 0/7] of: populate of_root node if bootloader doesn't

by Stephen Boyd

Arch maintainers, please ack/review patches. This is a resend of a series from Frank last year[1]. I worked in Rob's review comments to unconditionally call unflatten_device_tree() and fixup/audit calls to of_have_populated_dt() so that behavior doesn't change. I need this series so I can add DT based tests in the clk framework. Either I can merge it through the clk tree once everyone is happy, or Rob can merge it through the DT tree and provide some branch so I can base clk patches on it. Changes from v3 (https://lore.kernel.org/r/20240202195909.3458162-1-sboyd@kernel.org): * Made OF_UNITTEST depend on OF_EARLY_FLATREE * Made OF_EARLY_FLATREE depend on absence of arches that don't call unflatten_device_tree() * Added of_ prefix to dtb_ prefixed KUnit tests * Picked up tags Changes from v2 (https://lore.kernel.org/r/20240130004508.1700335-1-sboyd@kernel.org): * Reorder patches to have OF changes largely first * No longer modify initial_boot_params if ACPI=y * Put arm64 patch back to v1 Changes from v1 (https://lore.kernel.org/r/20240112200750.4062441-1-sboyd@kernel.org): * x86 patch included * arm64 knocks out initial dtb if acpi is in use * keep Kconfig hidden but def_bool enabled otherwise Changes from Frank's series[1]: * Add a DTB loaded kunit test * Make of_have_populated_dt() return false if the DTB isn't from the bootloader * Architecture calls made unconditional so that a root node is always made Frank Rowand (2): of: Create of_root if no dtb provided by firmware of: unittest: treat missing of_root as error instead of fixing up Stephen Boyd (5): of: Always unflatten in unflatten_and_copy_device_tree() um: Unconditionally call unflatten_device_tree() x86/of: Unconditionally call unflatten_and_copy_device_tree() arm64: Unconditionally call unflatten_device_tree() of: Add KUnit test to confirm DTB is loaded arch/arm64/kernel/setup.c | 3 +- arch/um/kernel/dtb.c | 14 ++++---- arch/x86/kernel/devicetree.c | 24 +++++++------- drivers/of/.kunitconfig | 3 ++ drivers/of/Kconfig | 14 ++++++-- drivers/of/Makefile | 4 ++- drivers/of/empty_root.dts | 6 ++++ drivers/of/fdt.c | 64 +++++++++++++++++++++++++++--------- drivers/of/of_test.c | 57 ++++++++++++++++++++++++++++++++ drivers/of/platform.c | 3 -- drivers/of/unittest.c | 16 +++------ include/linux/of.h | 25 ++++++++------ 12 files changed, 168 insertions(+), 65 deletions(-) create mode 100644 drivers/of/.kunitconfig create mode 100644 drivers/of/empty_root.dts create mode 100644 drivers/of/of_test.c [1] https://lore.kernel.org/r/20230317053415.2254616-1-frowand.list@gmail.com base-commit: 6613476e225e090cc9aad49be7fa504e290dd33d -- https://git.kernel.org/pub/scm/linux/kernel/git/clk/linux.git/ https://git.kernel.org/pub/scm/linux/kernel/git/sboyd/spmi.git

1 year, 1 month

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[PATCH v5 0/8] Split a folio to any lower order folios

by Zi Yan

From: Zi Yan <ziy(a)nvidia.com> Hi all, File folio supports any order and multi-size THP is upstreamed[1], so both file and anonymous folios can be >0 order. Currently, split_huge_page() only splits a huge page to order-0 pages, but splitting to orders higher than 0 might better utilize large folios, if done properly. In addition, Large Block Sizes in XFS support would benefit from it during truncate[2]. This patchset adds support for splitting a large folio to any lower order folios. The patchset is on top of mm-everything-2024-02-24-02-40. In addition to this implementation of split_huge_page_to_list_to_order(), a possible optimization could be splitting a large folio to arbitrary smaller folios instead of a single order. As both Hugh and Ryan pointed out [3,5] that split to a single order might not be optimal, an order-9 folio might be better split into 1 order-8, 1 order-7, ..., 1 order-1, and 2 order-0 folios, depending on subsequent folio operations. Leave this as future work. Changelog === Since v4[4] 1. Picked up Matthew's order-1 folio support in the page cache patch, so that XFS Large Block Sizes patchset can avoid additional code churn in split_huge_page_to_list_to_order(). 2. Dropped truncate change patch and corresponding testing code. 3. Removed thp_nr_pages() use in __split_huge_page() (per David Hildenbrand). 4. Fixed __split_page_owner() (per David Hildenbrand). 5. Changed unmap_folio() to only add TTU_SPLIT_HUGE_PMD if the folios is pmd mappable (per Ryan Roberts). 6. Moved swapcached folio split warning upfront and return -EINVAL (per Ryan Roberts). Since v3 --- 1. Excluded shmem folios and pagecache folios without FS support from splitting to any order (per Hugh Dickins). 2. Allowed splitting anonymous large folio to any lower order since multi-size THP is upstreamed. 3. Adapted selftests code to new framework. Since v2 --- 1. Fixed an issue in __split_page_owner() introduced during my rebase Since v1 --- 1. Changed split_page_memcg() and split_page_owner() parameter to use order 2. Used folio_test_pmd_mappable() in place of the equivalent code Details === * Patch 1 changes unmap_folio() to only add TTU_SPLIT_HUGE_PMD if the folio is pmd mappable. * Patch 2 adds support for order-1 page cache folio. * Patch 3 changes split_page_memcg() to use order instead of nr_pages. * Patch 4 changes split_page_owner() to use order instead of nr_pages. * Patch 5 and 6 add new_order parameter split_page_memcg() and split_page_owner() and prepare for upcoming changes. * Patch 7 adds split_huge_page_to_list_to_order() to split a huge page to any lower order. The original split_huge_page_to_list() calls split_huge_page_to_list_to_order() with new_order = 0. * Patch 8 adds a test API to debugfs and test cases in split_huge_page_test selftests. Comments and/or suggestions are welcome. [1] https://lore.kernel.org/all/20231207161211.2374093-1-ryan.roberts@arm.com/ [2] https://lore.kernel.org/linux-mm/20240226094936.2677493-1-kernel@pankajragh… [3] https://lore.kernel.org/linux-mm/9dd96da-efa2-5123-20d4-4992136ef3ad@google… [4] https://lore.kernel.org/linux-mm/cbb1d6a0-66dd-47d0-8733-f836fe050374@arm.c… [5] https://lore.kernel.org/linux-mm/20240213215520.1048625-1-zi.yan@sent.com/ Matthew Wilcox (Oracle) (1): mm: Support order-1 folios in the page cache Zi Yan (7): mm/huge_memory: only split PMD mapping when necessary in unmap_folio() mm/memcg: use order instead of nr in split_page_memcg() mm/page_owner: use order instead of nr in split_page_owner() mm: memcg: make memcg huge page split support any order split. mm: page_owner: add support for splitting to any order in split page_owner. mm: thp: split huge page to any lower order pages mm: huge_memory: enable debugfs to split huge pages to any order. include/linux/huge_mm.h | 21 ++- include/linux/memcontrol.h | 4 +- include/linux/page_owner.h | 14 +- mm/filemap.c | 2 - mm/huge_memory.c | 173 +++++++++++++----- mm/internal.h | 3 +- mm/memcontrol.c | 10 +- mm/page_alloc.c | 8 +- mm/page_owner.c | 6 +- mm/readahead.c | 3 - .../selftests/mm/split_huge_page_test.c | 115 +++++++++++- 11 files changed, 276 insertions(+), 83 deletions(-) -- 2.43.0

1 year, 1 month

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[PATCH v3 0/2] selftests/vDSO: Fix errors on LoongArch

by Tiezhu Yang

v3: Rebase on the next branch of linux-kselftest.git, modify the patch title and update the commit message v2: Rebase on 6.5-rc1 and update the commit message Tiezhu Yang (2): selftests/vDSO: Fix building errors on LoongArch selftests/vDSO: Fix runtime errors on LoongArch tools/testing/selftests/vDSO/vdso_config.h | 6 ++++- .../testing/selftests/vDSO/vdso_test_getcpu.c | 16 +++++------- .../selftests/vDSO/vdso_test_gettimeofday.c | 26 +++++-------------- 3 files changed, 18 insertions(+), 30 deletions(-) -- 2.42.0

1 year, 1 month

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