June 2024 - Linux-kselftest-mirror

[PATCH RFC 0/3] add support for mm-local memory allocations

by Roman Kagan

In a series posted a few years ago [1], a proposal was put forward to allow the kernel to allocate memory local to a mm and thus push it out of reach for current and future speculation-based cross-process attacks. We still believe this is a nice thing to have. However, in the time passed since that post Linux mm has grown quite a few new goodies, so we'd like to explore possibilities to implement this functionality with less effort and churn leveraging the now available facilities. Specifically, this is a proof-of-concept attempt to implement mm-local allocations piggy-backing on memfd_secret(), using regular user addressess but pinning the pages and flipping the user/supervisor flag on the respective PTEs to make them directly accessible from kernel, and sealing the VMA to prevent userland from taking over the address range. The approach allowed to delegate all the heavy lifting -- address management, interactions with the direct map, cleanup on mm teardown -- to the existing infrastructure, and required zero architecture-specific code. Compared to the approach used in the orignal series, where a dedicated kernel address range and thus a dedicated PGD was used for mm-local allocations, the one proposed here may have certain drawbacks, in particular - using user addresses for kernel memory may violate assumptions in various parts of kernel code which we may not have identified with smoke tests we did - the allocated addresses are guessable by the userland (ATM they are even visible in /proc/PID/maps but that's fixable) which may weaken the security posture Also included is a simple test driver and selftest to smoke test and showcase the feature. The code is PoC RFC and lacks a lot of checks and special case handling, but demonstrates the idea. We'd appreciate any feedback on whether it's a viable approach or it should better be abandoned in favor of the one with dedicated PGD / kernel address range or yet something else. [1] https://lore.kernel.org/lkml/20190612170834.14855-1-mhillenb@amazon.de/ Fares Mehanna (2): mseal: expose interface to seal / unseal user memory ranges mm/secretmem: implement mm-local kernel allocations Roman Kagan (1): drivers/misc: add test driver and selftest for proclocal allocator drivers/misc/Makefile | 1 + tools/testing/selftests/proclocal/Makefile | 6 + include/linux/secretmem.h | 8 + mm/internal.h | 7 + drivers/misc/proclocal-test.c | 200 +++++++++++++++++ mm/gup.c | 4 +- mm/mseal.c | 81 ++++--- mm/secretmem.c | 208 ++++++++++++++++++ .../selftests/proclocal/proclocal-test.c | 150 +++++++++++++ drivers/misc/Kconfig | 15 ++ tools/testing/selftests/proclocal/.gitignore | 1 + 11 files changed, 649 insertions(+), 32 deletions(-) create mode 100644 tools/testing/selftests/proclocal/Makefile create mode 100644 drivers/misc/proclocal-test.c create mode 100644 tools/testing/selftests/proclocal/proclocal-test.c create mode 100644 tools/testing/selftests/proclocal/.gitignore -- 2.34.1 Amazon Web Services Development Center Germany GmbH Krausenstr. 38 10117 Berlin Geschaeftsfuehrung: Christian Schlaeger, Jonathan Weiss Eingetragen am Amtsgericht Charlottenburg unter HRB 257764 B Sitz: Berlin Ust-ID: DE 365 538 597

8 months

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[PATCH v3 0/3] riscv: mm: Extend mappable memory up to hint address

by Charlie Jenkins

On riscv, mmap currently returns an address from the largest address space that can fit entirely inside of the hint address. This makes it such that the hint address is almost never returned. This patch raises the mappable area up to and including the hint address. This allows mmap to often return the hint address, which allows a performance improvement over searching for a valid address as well as making the behavior more similar to other architectures. Note that a previous patch introduced stronger semantics compared to other architectures for riscv mmap. On riscv, mmap will not use bits in the upper bits of the virtual address depending on the hint address. On other architectures, a random address is returned in the address space requested. On all architectures the hint address will be returned if it is available. This allows riscv applications to configure how many bits in the virtual address should be left empty. This has the two benefits of being able to request address spaces that are smaller than the default and doesn't require the application to know the page table layout of riscv. Signed-off-by: Charlie Jenkins <charlie(a)rivosinc.com> --- Changes in v3: - Add back forgotten semi-colon - Fix test cases - Add support for rv32 - Change cover letter name so it's not the same as patch 1 - Link to v2: https://lore.kernel.org/r/20240130-use_mmap_hint_address-v2-0-f34ebfd33053@… Changes in v2: - Add back forgotten "mmap_end = STACK_TOP_MAX" - Link to v1: https://lore.kernel.org/r/20240129-use_mmap_hint_address-v1-0-4c74da813ba1@… --- Charlie Jenkins (3): riscv: mm: Use hint address in mmap if available selftests: riscv: Generalize mm selftests docs: riscv: Define behavior of mmap Documentation/arch/riscv/vm-layout.rst | 16 ++-- arch/riscv/include/asm/processor.h | 27 +++--- tools/testing/selftests/riscv/mm/mmap_bottomup.c | 23 +---- tools/testing/selftests/riscv/mm/mmap_default.c | 23 +---- tools/testing/selftests/riscv/mm/mmap_test.h | 107 ++++++++++++++--------- 5 files changed, 83 insertions(+), 113 deletions(-) --- base-commit: 556e2d17cae620d549c5474b1ece053430cd50bc change-id: 20240119-use_mmap_hint_address-f9f4b1b6f5f1 -- - Charlie

8 months

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[PATCH] tools: Copy linux/align.h into tools/

by Ackerley Tng

This provides alignment macros for use in selftests. Also clean up tools/include/linux/bitmap.h's inline definition of IS_ALIGNED(). Signed-off-by: Ackerley Tng <ackerleytng(a)google.com> --- tools/include/linux/align.h | 15 +++++++++++++++ tools/include/linux/bitmap.h | 2 +- 2 files changed, 16 insertions(+), 1 deletion(-) create mode 100644 tools/include/linux/align.h diff --git a/tools/include/linux/align.h b/tools/include/linux/align.h new file mode 100644 index 000000000000..2b4acec7b95a --- /dev/null +++ b/tools/include/linux/align.h @@ -0,0 +1,15 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _LINUX_ALIGN_H +#define _LINUX_ALIGN_H + +#include <linux/const.h> + +/* @a is a power of 2 value */ +#define ALIGN(x, a) __ALIGN_KERNEL((x), (a)) +#define ALIGN_DOWN(x, a) __ALIGN_KERNEL((x) - ((a) - 1), (a)) +#define __ALIGN_MASK(x, mask) __ALIGN_KERNEL_MASK((x), (mask)) +#define PTR_ALIGN(p, a) ((typeof(p))ALIGN((unsigned long)(p), (a))) +#define PTR_ALIGN_DOWN(p, a) ((typeof(p))ALIGN_DOWN((unsigned long)(p), (a))) +#define IS_ALIGNED(x, a) (((x) & ((typeof(x))(a) - 1)) == 0) + +#endif /* _LINUX_ALIGN_H */ diff --git a/tools/include/linux/bitmap.h b/tools/include/linux/bitmap.h index f3566ea0f932..8c6852dba04f 100644 --- a/tools/include/linux/bitmap.h +++ b/tools/include/linux/bitmap.h @@ -3,6 +3,7 @@ #define _TOOLS_LINUX_BITMAP_H #include <string.h> +#include <linux/align.h> #include <linux/bitops.h> #include <linux/find.h> #include <stdlib.h> @@ -126,7 +127,6 @@ static inline bool bitmap_and(unsigned long *dst, const unsigned long *src1, #define BITMAP_MEM_ALIGNMENT (8 * sizeof(unsigned long)) #endif #define BITMAP_MEM_MASK (BITMAP_MEM_ALIGNMENT - 1) -#define IS_ALIGNED(x, a) (((x) & ((typeof(x))(a) - 1)) == 0) static inline bool bitmap_equal(const unsigned long *src1, const unsigned long *src2, unsigned int nbits) -- 2.39.2.722.g9855ee24e9-goog

8 months

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[PATCH bpf-next v2 0/2] selftests/bpf: new MPTCP subflow subtest

by Matthieu Baerts (NGI0)

In this series from Geliang, modifying MPTCP BPF selftests, we have: - A new MPTCP subflow BPF program setting socket options per subflow: it looks better to have this old test program in the BPF selftests to track regressions and to serve as example. Note: Nicolas is no longer working for Tessares, but he did this work while working for them, and his email address is no longer available. - A new MPTCP BPF subtest validating this new BPF program. Signed-off-by: Matthieu Baerts (NGI0) <matttbe(a)kernel.org> --- Changes in v2: - Previous patches 1/4 and 2/4 have been dropped from this series: - 1/4: "selftests/bpf: Handle SIGINT when creating netns": - A new version, more generic and no longer specific to MPTCP BPF selftest will be sent later, as part of a new series. (Alexei) - 2/4: "selftests/bpf: Add RUN_MPTCP_TEST macro": - Removed, not to hide helper functions in macros. (Alexei) - The commit message of patch 1/2 has been clarified to avoid some possible confusions spot by Alexei. - Link to v1: https://lore.kernel.org/r/20240507-upstream-bpf-next-20240506-mptcp-subflow… --- Geliang Tang (1): selftests/bpf: Add mptcp subflow subtest Nicolas Rybowski (1): selftests/bpf: Add mptcp subflow example tools/testing/selftests/bpf/prog_tests/mptcp.c | 109 ++++++++++++++++++++++ tools/testing/selftests/bpf/progs/mptcp_subflow.c | 70 ++++++++++++++ 2 files changed, 179 insertions(+) --- base-commit: 009367099eb61a4fc2af44d4eb06b6b4de7de6db change-id: 20240506-upstream-bpf-next-20240506-mptcp-subflow-test-faef6654bfa3 Best regards, -- Matthieu Baerts (NGI0) <matttbe(a)kernel.org>

8 months

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[PATCH] selftests/ftrace: Fix test to handle both old and new kernels

by Steven Rostedt

From: "Steven Rostedt (Google)" <rostedt(a)goodmis.org> The function "scheduler_tick" was renamed to "sched_tick" and a selftest that used that function for testing function trace filtering used that function as part of the test. But the change causes it to fail when run on older kernels. As tests should not fail on older kernels, add a check to see which name is available before testing. Fixes: 86dd6c04ef9f2 ("sched/balancing: Rename scheduler_tick() => sched_tick()") Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org> --- .../ftrace/test.d/ftrace/func_set_ftrace_file.tc | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/ftrace/test.d/ftrace/func_set_ftrace_file.tc b/tools/testing/selftests/ftrace/test.d/ftrace/func_set_ftrace_file.tc index 073a748b9380..263f6b798c85 100644 --- a/tools/testing/selftests/ftrace/test.d/ftrace/func_set_ftrace_file.tc +++ b/tools/testing/selftests/ftrace/test.d/ftrace/func_set_ftrace_file.tc @@ -19,7 +19,14 @@ fail() { # mesg FILTER=set_ftrace_filter FUNC1="schedule" -FUNC2="sched_tick" +if grep '^sched_tick\b' available_filter_functions; then + FUNC2="sched_tick" +elif grep '^scheduler_tick\b' available_filter_functions; then + FUNC2="scheduler_tick" +else + exit_unresolved +fi + ALL_FUNCS="#### all functions enabled ####" -- 2.43.0

8 months, 1 week

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[PATCH 0/3] binfmt_elf: Honor PT_LOAD alignment for static PIE

by Kees Cook

Hi, This attempts to implement PT_LOAD p_align support for static PIE builds. I intend this to go into -next after the coming merge window so we can maximize bake time. In the past we've had regressions with both the selftests and the ELF loader. Hopefully we can shake everything out over a few months. :) Thanks! -Kees Kees Cook (3): selftests/exec: Build both static and non-static load_address tests binfmt_elf: Calculate total_size earlier binfmt_elf: Honor PT_LOAD alignment for static PIE fs/binfmt_elf.c | 94 ++++++++++++++------- tools/testing/selftests/exec/Makefile | 19 +++-- tools/testing/selftests/exec/load_address.c | 67 ++++++++++++--- 3 files changed, 130 insertions(+), 50 deletions(-) -- 2.34.1

8 months, 1 week

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[PATCH 1/1] KVM: selftests: add kvmclock drift test

by Dongli Zhang

There is kvmclock drift issue during the vCPU hotplug. It has been fixed by the commit c52ffadc65e2 ("KVM: x86: Don't unnecessarily force masterclock update on vCPU hotplug"). This is to add the test to verify if the master clock is updated when we write 0 to MSR_IA32_TSC from the host side. Here is the usage example on the KVM with the bugfix reverted. $ ./kvm_clock_drift -v -p 5 kvmclock based on old pvclock_vcpu_time_info: 5012221999 version: 2 tsc_timestamp: 3277968 system_time: 11849519 tsc_to_system_mul: 2152530255 tsc_shift: 0 flags: 1 kvmclock based on new pvclock_vcpu_time_info: 5012222411 version: 4 tsc_timestamp: 9980576184 system_time: 5012222411 tsc_to_system_mul: 2152530255 tsc_shift: 0 flags: 1 ==== Test Assertion Failure ==== x86_64/kvm_clock_drift.c:216: clock_old == clock_new pid=14257 tid=14257 errno=4 - Interrupted system call 1 0x000000000040277b: main at kvm_clock_drift.c:216 2 0x00007f7766fa7e44: ?? ??:0 3 0x000000000040286d: _start at ??:? kvmclock drift detected, old=5012221999, new=5012222411 Signed-off-by: Dongli Zhang <dongli.zhang(a)oracle.com> --- tools/testing/selftests/kvm/Makefile | 1 + .../selftests/kvm/x86_64/kvm_clock_drift.c | 223 ++++++++++++++++++ 2 files changed, 224 insertions(+) create mode 100644 tools/testing/selftests/kvm/x86_64/kvm_clock_drift.c diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile index 4412b42d95de..c665d0d8d348 100644 --- a/tools/testing/selftests/kvm/Makefile +++ b/tools/testing/selftests/kvm/Makefile @@ -84,6 +84,7 @@ TEST_GEN_PROGS_x86_64 += x86_64/hyperv_features TEST_GEN_PROGS_x86_64 += x86_64/hyperv_ipi TEST_GEN_PROGS_x86_64 += x86_64/hyperv_svm_test TEST_GEN_PROGS_x86_64 += x86_64/hyperv_tlb_flush +TEST_GEN_PROGS_x86_64 += x86_64/kvm_clock_drift TEST_GEN_PROGS_x86_64 += x86_64/kvm_clock_test TEST_GEN_PROGS_x86_64 += x86_64/kvm_pv_test TEST_GEN_PROGS_x86_64 += x86_64/monitor_mwait_test diff --git a/tools/testing/selftests/kvm/x86_64/kvm_clock_drift.c b/tools/testing/selftests/kvm/x86_64/kvm_clock_drift.c new file mode 100644 index 000000000000..324f0dbc5762 --- /dev/null +++ b/tools/testing/selftests/kvm/x86_64/kvm_clock_drift.c @@ -0,0 +1,223 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * The kvmclock drift test. Emulate vCPU hotplug and online to verify if + * there is kvmclock drift. + * + * Adapted from steal_time.c + * + * Copyright (C) 2020, Red Hat, Inc. + * Copyright (C) 2024 Oracle and/or its affiliates. + */ + +#include <asm/kvm_para.h> +#include <asm/pvclock.h> +#include <asm/pvclock-abi.h> +#include <sys/stat.h> + +#include "kvm_util.h" +#include "processor.h" + +#define NR_VCPUS 2 +#define NR_SLOTS 2 +#define KVMCLOCK_SIZE sizeof(struct pvclock_vcpu_time_info) +/* + * KVMCLOCK_GPA is identity mapped + */ +#define KVMCLOCK_GPA (1 << 30) + +static uint64_t kvmclock_gpa = KVMCLOCK_GPA; + +static void guest_code(int cpu) +{ + struct pvclock_vcpu_time_info *kvmclock; + + /* + * vCPU#0 is to detect the change of pvclock_vcpu_time_info + */ + if (cpu == 0) { + GUEST_SYNC(0); + + kvmclock = (struct pvclock_vcpu_time_info *) kvmclock_gpa; + wrmsr(MSR_KVM_SYSTEM_TIME_NEW, kvmclock_gpa | KVM_MSR_ENABLED); + + /* + * Backup the pvclock_vcpu_time_info before vCPU#1 hotplug + */ + kvmclock[1] = kvmclock[0]; + + GUEST_SYNC(2); + /* + * Enter the guest to update pvclock_vcpu_time_info + */ + GUEST_SYNC(4); + } + + /* + * vCPU#1 is to emulate the vCPU hotplug + */ + if (cpu == 1) { + GUEST_SYNC(1); + /* + * This is after the host side MSR_IA32_TSC + */ + GUEST_SYNC(3); + } +} + +static void run_vcpu(struct kvm_vcpu *vcpu) +{ + struct ucall uc; + + vcpu_run(vcpu); + + switch (get_ucall(vcpu, &uc)) { + case UCALL_SYNC: + case UCALL_DONE: + break; + case UCALL_ABORT: + REPORT_GUEST_ASSERT(uc); + default: + TEST_ASSERT(false, "Unexpected exit: %s", + exit_reason_str(vcpu->run->exit_reason)); + } +} + +static void kvmclock_dump(struct pvclock_vcpu_time_info *kvmclock) +{ + pr_info(" version: %u\n", kvmclock->version); + pr_info(" tsc_timestamp: %lu\n", kvmclock->tsc_timestamp); + pr_info(" system_time: %lu\n", kvmclock->system_time); + pr_info(" tsc_to_system_mul: %u\n", kvmclock->tsc_to_system_mul); + pr_info(" tsc_shift: %d\n", kvmclock->tsc_shift); + pr_info(" flags: %u\n", kvmclock->flags); + pr_info("\n"); +} + +#define CLOCKSOURCE_PATH "/sys/devices/system/clocksource/clocksource0/current_clocksource" + +static void check_clocksource(void) +{ + char *clk_name; + struct stat st; + FILE *fp; + + fp = fopen(CLOCKSOURCE_PATH, "r"); + if (!fp) { + pr_info("failed to open clocksource file: %d; assuming TSC.\n", + errno); + return; + } + + if (fstat(fileno(fp), &st)) { + pr_info("failed to stat clocksource file: %d; assuming TSC.\n", + errno); + goto out; + } + + clk_name = malloc(st.st_size); + TEST_ASSERT(clk_name, "failed to allocate buffer to read file\n"); + + if (!fgets(clk_name, st.st_size, fp)) { + pr_info("failed to read clocksource file: %d; assuming TSC.\n", + ferror(fp)); + goto out; + } + + TEST_ASSERT(!strncmp(clk_name, "tsc\n", st.st_size), + "clocksource not supported: %s", clk_name); +out: + fclose(fp); +} + +int main(int argc, char *argv[]) +{ + struct pvclock_vcpu_time_info *kvmclock; + struct kvm_vcpu *vcpus[NR_VCPUS]; + uint64_t clock_old, clock_new; + bool verbose = false; + unsigned int gpages; + struct kvm_vm *vm; + int period = 2; + uint64_t tsc; + int opt; + + check_clocksource(); + + while ((opt = getopt(argc, argv, "p:vh")) != -1) { + switch (opt) { + case 'p': + period = atoi_positive("The period (seconds) between vCPU hotplug", + optarg); + break; + case 'v': + verbose = true; + break; + case 'h': + default: + pr_info("usage: %s [-p period (seconds)] [-v]\n", argv[0]); + exit(1); + } + } + + vm = vm_create_with_vcpus(NR_VCPUS, guest_code, vcpus); + gpages = vm_calc_num_guest_pages(VM_MODE_DEFAULT, + KVMCLOCK_SIZE * NR_SLOTS); + vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, + KVMCLOCK_GPA, 1, gpages, 0); + virt_map(vm, KVMCLOCK_GPA, KVMCLOCK_GPA, gpages); + + vcpu_args_set(vcpus[0], 1, 0); + vcpu_args_set(vcpus[1], 1, 1); + + /* + * Run vCPU#0 and vCPU#1 to update both pvclock_vcpu_time_info and + * master clock + */ + run_vcpu(vcpus[0]); + run_vcpu(vcpus[1]); + + /* + * Run vCPU#0 to backup the current pvclock_vcpu_time_info + */ + run_vcpu(vcpus[0]); + + sleep(period); + + /* + * Emulate the hotplug of vCPU#1 + */ + vcpu_set_msr(vcpus[1], MSR_IA32_TSC, 0); + + /* + * Emulate the online of vCPU#1 + */ + run_vcpu(vcpus[1]); + + /* + * Run vCPU#0 to backup the new pvclock_vcpu_time_info to detect + * if there is any change or kvmclock drift + */ + run_vcpu(vcpus[0]); + + kvmclock = addr_gva2hva(vm, kvmclock_gpa); + tsc = kvmclock[0].tsc_timestamp; + clock_old = __pvclock_read_cycles(&kvmclock[1], tsc); + clock_new = __pvclock_read_cycles(&kvmclock[0], tsc); + + if (verbose) { + pr_info("kvmclock based on old pvclock_vcpu_time_info: %lu\n", + clock_old); + kvmclock_dump(&kvmclock[1]); + pr_info("kvmclock based on new pvclock_vcpu_time_info: %lu\n", + clock_new); + kvmclock_dump(&kvmclock[0]); + } + + TEST_ASSERT(clock_old == clock_new, + "kvmclock drift detected, old=%lu, new=%lu", + clock_old, clock_new); + + kvm_vm_free(vm); + + return 0; +} base-commit: f2a3fb7234e52f72ff4a38364dbf639cf4c7d6c6 -- 2.34.1

8 months, 1 week

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[PATCH] selftests/ftrace: Add required dependency for kprobe tests

by Masami Hiramatsu (Google)

From: Masami Hiramatsu (Google) <mhiramat(a)kernel.org> kprobe_args_{char,string}.tc are using available_filter_functions file which is provided by function tracer. Thus if function tracer is disabled, these tests are failed on recent kernels because tracefs_create_dir is not raised events by adding a dynamic event. Add available_filter_functions to requires line. Fixes: 7c1130ea5cae ("test: ftrace: Fix kprobe test for eventfs") Signed-off-by: Masami Hiramatsu (Google) <mhiramat(a)kernel.org> --- .../ftrace/test.d/kprobe/kprobe_args_char.tc | 2 +- .../ftrace/test.d/kprobe/kprobe_args_string.tc | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_char.tc b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_char.tc index e21c9c27ece4..77f4c07cdcb8 100644 --- a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_char.tc +++ b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_char.tc @@ -1,7 +1,7 @@ #!/bin/sh # SPDX-License-Identifier: GPL-2.0 # description: Kprobe event char type argument -# requires: kprobe_events +# requires: kprobe_events available_filter_functions case `uname -m` in x86_64) diff --git a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_string.tc b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_string.tc index 93217d459556..39001073f7ed 100644 --- a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_string.tc +++ b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_args_string.tc @@ -1,7 +1,7 @@ #!/bin/sh # SPDX-License-Identifier: GPL-2.0 # description: Kprobe event string type argument -# requires: kprobe_events +# requires: kprobe_events available_filter_functions case `uname -m` in x86_64)

8 months, 1 week

3
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[PATCH v5 00/28] NT synchronization primitive driver

by Elizabeth Figura

This patch series implements a new char misc driver, /dev/ntsync, which is used to implement Windows NT synchronization primitives. NT synchronization primitives are unique in that the wait functions both are vectored, operate on multiple types of object with different behaviour (mutex, semaphore, event), and affect the state of the objects they wait on. This model is not compatible with existing kernel synchronization objects or interfaces, and therefore the ntsync driver implements its own wait queues and locking. This patch series is rebased against the "char-misc-next" branch of gregkh/char-misc.git. == 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 performance measurements described below are copied from earlier versions of the patch set. While some of the code has changed, I do not currently anticipate that it has changed drastically enough to affect those measurements. 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 27/28 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 == Previous versions == Changes from v4: * Rework wait-all locking code to avoid taking more than one spinlock at a time, and also to fix a race where the wait-all lock would not be not correctly taken. The new locking mechanism involves taking a simple spinlock for normal "any" waits, and taking a device-wide mutex for "all" waits or when locking any object that is involved in an "all" wait. The mechanism was written by Peter Zijlstra. * Try to reword or clarify various parts of the documentation (patch 27), per Peter Zijlstra. * I did not rename NTSYNC_IOC_SEM_POST to RELEASE (like NT) although this was suggested by Peter Zijlstra, mostly because it's not clear to me that renaming an already committed ioctl would be fine. The API committed isn't actually usable yet, though, so if altering it would be fine on those grounds, I can revise this series to rename the function accordingly. * Similarly, I did not change the create ioctls to return the fd directly, although this was suggested and would be a bit simpler and cleaner, because NTSYNC_IOC_CREATE_SEM already exists upstream and returns the fd through a struct. I can make this change in the next revision if that'd be preferable. I also still would appreciate a clarification on the advice in [1]. [1] https://docs.kernel.org/driver-api/ioctl.html#return-code * Link to v4: https://lore.kernel.org/lkml/20240416010837.333694-1-zfigura@codeweavers.co… * Link to v3: https://lore.kernel.org/lkml/20240329000621.148791-1-zfigura@codeweavers.co… * Link to v2: https://lore.kernel.org/lkml/20240219223833.95710-1-zfigura@codeweavers.com/ * 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 (28): 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. 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. ntsync: No longer depend on BROKEN. Documentation/userspace-api/index.rst | 1 + Documentation/userspace-api/ntsync.rst | 398 +++++ MAINTAINERS | 9 + drivers/misc/Kconfig | 1 - drivers/misc/ntsync.c | 989 +++++++++++- include/uapi/linux/ntsync.h | 39 + tools/testing/selftests/Makefile | 1 + .../selftests/drivers/ntsync/.gitignore | 1 + .../testing/selftests/drivers/ntsync/Makefile | 7 + tools/testing/selftests/drivers/ntsync/config | 1 + .../testing/selftests/drivers/ntsync/ntsync.c | 1407 +++++++++++++++++ 11 files changed, 2850 insertions(+), 4 deletions(-) create mode 100644 Documentation/userspace-api/ntsync.rst create mode 100644 tools/testing/selftests/drivers/ntsync/.gitignore 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: f5b335dc025cfee90957efa90dc72fada0d5abb4 -- 2.43.0

8 months, 2 weeks

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[PATCH] tracing/selftests: Run the ownership test twice

by Steven Rostedt

From: "Steven Rostedt (Google)" <rostedt(a)goodmis.org> A regression happened where running the ownership test passes on the first iteration but fails running it a second time. This was caught and fixed, but a later change brought it back. The regression was missed because the automated tests only run the tests once per boot. Change the ownership test to iterate through the tests twice, as this will catch the regression with a single run. Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org> --- .../ftrace/test.d/00basic/test_ownership.tc | 34 +++++++++++-------- 1 file changed, 20 insertions(+), 14 deletions(-) diff --git a/tools/testing/selftests/ftrace/test.d/00basic/test_ownership.tc b/tools/testing/selftests/ftrace/test.d/00basic/test_ownership.tc index c45094d1e1d2..71e43a92352a 100644 --- a/tools/testing/selftests/ftrace/test.d/00basic/test_ownership.tc +++ b/tools/testing/selftests/ftrace/test.d/00basic/test_ownership.tc @@ -83,32 +83,38 @@ run_tests() { done } -mount -o remount,"$new_options" . +# Run the tests twice as leftovers can cause issues +for loop in 1 2 ; do -run_tests + echo "Running iteration $loop" -mount -o remount,"$mount_options" . + mount -o remount,"$new_options" . -for d in "." "events" "events/sched" "events/sched/sched_switch" "events/sched/sched_switch/enable" $canary; do - test "$d" $original_group -done + run_tests + + mount -o remount,"$mount_options" . + + for d in "." "events" "events/sched" "events/sched/sched_switch" "events/sched/sched_switch/enable" $canary; do + test "$d" $original_group + done # check instances as well -chgrp $other_group instances + chgrp $other_group instances -instance="$(mktemp -u test-XXXXXX)" + instance="$(mktemp -u test-XXXXXX)" -mkdir instances/$instance + mkdir instances/$instance -cd instances/$instance + cd instances/$instance -run_tests + run_tests -cd ../.. + cd ../.. -rmdir instances/$instance + rmdir instances/$instance -chgrp $original_group instances + chgrp $original_group instances +done exit 0 -- 2.43.0

8 months, 2 weeks

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Linux-kselftest-mirror June 2024