January 2024 - Linux-kselftest-mirror

[PATCH v4 00/10] Add support for synchronous signals on perf events

by Marco Elver

The perf subsystem today unifies various tracing and monitoring features, from both software and hardware. One benefit of the perf subsystem is automatically inheriting events to child tasks, which enables process-wide events monitoring with low overheads. By default perf events are non-intrusive, not affecting behaviour of the tasks being monitored. For certain use-cases, however, it makes sense to leverage the generality of the perf events subsystem and optionally allow the tasks being monitored to receive signals on events they are interested in. This patch series adds the option to synchronously signal user space on events. To better support process-wide synchronous self-monitoring, without events propagating to children that do not share the current process's shared environment, two pre-requisite patches are added to optionally restrict inheritance to CLONE_THREAD, and remove events on exec (without affecting the parent). Examples how to use these features can be found in the tests added at the end of the series. In addition to the tests added, the series has also been subjected to syzkaller fuzzing (focus on 'kernel/events/' coverage). Motivation and Example Uses --------------------------- 1. Our immediate motivation is low-overhead sampling-based race detection for user space [1]. By using perf_event_open() at process initialization, we can create hardware breakpoint/watchpoint events that are propagated automatically to all threads in a process. As far as we are aware, today no existing kernel facility (such as ptrace) allows us to set up process-wide watchpoints with minimal overheads (that are comparable to mprotect() of whole pages). 2. Other low-overhead error detectors that rely on detecting accesses to certain memory locations or code, process-wide and also only in a specific set of subtasks or threads. [1] https://llvm.org/devmtg/2020-09/slides/Morehouse-GWP-Tsan.pdf Other ideas for use-cases we found interesting, but should only illustrate the range of potential to further motivate the utility (we're sure there are more): 3. Code hot patching without full stop-the-world. Specifically, by setting a code breakpoint to entry to the patched routine, then send signals to threads and check that they are not in the routine, but without stopping them further. If any of the threads will enter the routine, it will receive SIGTRAP and pause. 4. Safepoints without mprotect(). Some Java implementations use "load from a known memory location" as a safepoint. When threads need to be stopped, the page containing the location is mprotect()ed and threads get a signal. This could be replaced with a watchpoint, which does not require a whole page nor DTLB shootdowns. 5. Threads receiving signals on performance events to throttle/unthrottle themselves. 6. Tracking data flow globally. Changelog --------- v4: * Fix for parent and child racing to exit in sync_child_event(). * Fix race between irq_work running and task's sighand being released by release_task(). * Generalize setting si_perf and si_addr independent of event type; introduces perf_event_attr::sig_data, which can be set by user space to be propagated to si_perf. * Warning in perf_sigtrap() if ctx->task and current mismatch; we expect this on architectures that do not properly implement arch_irq_work_raise(). * Require events that want sigtrap to be associated with a task. * Dropped "perf: Add breakpoint information to siginfo on SIGTRAP" in favor of more generic solution (perf_event_attr::sig_data). v3: * Add patch "perf: Rework perf_event_exit_event()" to beginning of series, courtesy of Peter Zijlstra. * Rework "perf: Add support for event removal on exec" based on the added "perf: Rework perf_event_exit_event()". * Fix kselftests to work with more recent libc, due to the way it forces using the kernel's own siginfo_t. * Add basic perf-tool built-in test. v2/RFC: https://lkml.kernel.org/r/20210310104139.679618-1-elver@google.com * Patch "Support only inheriting events if cloned with CLONE_THREAD" added to series. * Patch "Add support for event removal on exec" added to series. * Patch "Add kselftest for process-wide sigtrap handling" added to series. * Patch "Add kselftest for remove_on_exec" added to series. * Implicitly restrict inheriting events if sigtrap, but the child was cloned with CLONE_CLEAR_SIGHAND, because it is not generally safe if the child cleared all signal handlers to continue sending SIGTRAP. * Various minor fixes (see details in patches). v1/RFC: https://lkml.kernel.org/r/20210223143426.2412737-1-elver@google.com Pre-series: The discussion at [2] led to the changes in this series. The approach taken in "Add support for SIGTRAP on perf events" to trigger the signal was suggested by Peter Zijlstra in [3]. [2] https://lore.kernel.org/lkml/CACT4Y+YPrXGw+AtESxAgPyZ84TYkNZdP0xpocX2jwVAbZ… [3] https://lore.kernel.org/lkml/YBv3rAT566k+6zjg@hirez.programming.kicks-ass.n… Marco Elver (9): perf: Apply PERF_EVENT_IOC_MODIFY_ATTRIBUTES to children perf: Support only inheriting events if cloned with CLONE_THREAD perf: Add support for event removal on exec signal: Introduce TRAP_PERF si_code and si_perf to siginfo perf: Add support for SIGTRAP on perf events selftests/perf_events: Add kselftest for process-wide sigtrap handling selftests/perf_events: Add kselftest for remove_on_exec tools headers uapi: Sync tools/include/uapi/linux/perf_event.h perf test: Add basic stress test for sigtrap handling Peter Zijlstra (1): perf: Rework perf_event_exit_event() arch/m68k/kernel/signal.c | 3 + arch/x86/kernel/signal_compat.c | 5 +- fs/signalfd.c | 4 + include/linux/compat.h | 2 + include/linux/perf_event.h | 9 +- include/linux/signal.h | 1 + include/uapi/asm-generic/siginfo.h | 6 +- include/uapi/linux/perf_event.h | 12 +- include/uapi/linux/signalfd.h | 4 +- kernel/events/core.c | 302 +++++++++++++----- kernel/fork.c | 2 +- kernel/signal.c | 11 + tools/include/uapi/linux/perf_event.h | 12 +- tools/perf/tests/Build | 1 + tools/perf/tests/builtin-test.c | 5 + tools/perf/tests/sigtrap.c | 150 +++++++++ tools/perf/tests/tests.h | 1 + .../testing/selftests/perf_events/.gitignore | 3 + tools/testing/selftests/perf_events/Makefile | 6 + tools/testing/selftests/perf_events/config | 1 + .../selftests/perf_events/remove_on_exec.c | 260 +++++++++++++++ tools/testing/selftests/perf_events/settings | 1 + .../selftests/perf_events/sigtrap_threads.c | 210 ++++++++++++ 23 files changed, 924 insertions(+), 87 deletions(-) create mode 100644 tools/perf/tests/sigtrap.c create mode 100644 tools/testing/selftests/perf_events/.gitignore create mode 100644 tools/testing/selftests/perf_events/Makefile create mode 100644 tools/testing/selftests/perf_events/config create mode 100644 tools/testing/selftests/perf_events/remove_on_exec.c create mode 100644 tools/testing/selftests/perf_events/settings create mode 100644 tools/testing/selftests/perf_events/sigtrap_threads.c -- 2.31.0.208.g409f899ff0-goog

1 year, 2 months

5
29
0 0

[PATCH] tools/testing/selftests/x86: add dlclose function in the vdso_restorer.c

by liujing

in the main function of vdso_restorer.c,there is a dlopen function, but there is no dlclose function to close the file Signed-off-by: liujing <liujing(a)cmss.chinamobile.com> --- tools/testing/selftests/x86/vdso_restorer.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/tools/testing/selftests/x86/vdso_restorer.c b/tools/testing/selftests/x86/vdso_restorer.c index fe99f2434155..a0b1155dee31 100644 --- a/tools/testing/selftests/x86/vdso_restorer.c +++ b/tools/testing/selftests/x86/vdso_restorer.c @@ -57,6 +57,8 @@ int main() return 0; } + dlclose(vdso); + memset(&sa, 0, sizeof(sa)); sa.handler = handler_with_siginfo; sa.flags = SA_SIGINFO; -- 2.18.2

1 year, 2 months

2
1
0 0

selftests: clone3: clone3_cap_checkpoint_restore fails - Could not set CAP_CHECKPOINT_RESTORE

by Naresh Kamboju

selftests clone3 cap_checkpoint_restore fails on all devices. Reported-by: Linux Kernel Functional Testing <lkft(a)linaro.org> [ 97.198602] audit: type=1701 audit(1651167820.383:12): auid=4294967295 uid=0 gid=0 ses=4294967295 pid=1732 comm=\"clone3_cap_chec\" exe=\"/opt/kselftests/default-in-kernel/clone3/clone3_cap_checkpoint_restore\" sig=6 res=1 # selftests: clone3: clone3_cap_checkpoint_restore # TAP version 13 # 1..1 # # Starting 1 tests from 1 test cases. # # RUN global.clone3_cap_checkpoint_restore ... # # clone3_cap_checkpoint_restore.c:155:clone3_cap_checkpoint_restore:Child has PID 1733 # # clone3() syscall supported # cap_set_proc: Operation not permitted # # clone3_cap_checkpoint_restore.c:164:clone3_cap_checkpoint_restore:Expected set_capability() (-1) == 0 (0) # # clone3_cap_checkpoint_restore.c:165:clone3_cap_checkpoint_restore:Could not set CAP_CHECKPOINT_RESTORE # # clone3_cap_checkpoint_restore: Test terminated by assertion # # FAIL global.clone3_cap_checkpoint_restore # not ok 1 global.clone3_cap_checkpoint_restore # # FAILED: 0 / 1 tests passed. # # Totals: pass:0 fail:1 xfail:0 xpass:0 skip:0 error:0 not ok 4 selftests: clone3: clone3_cap_checkpoint_restore # exit=1 Test details links, https://lkft.validation.linaro.org/scheduler/job/5812724#L2074 Test results comparison link, https://qa-reports.linaro.org/lkft/linux-next-master/build/next-20221107/te… https://qa-reports.linaro.org/lkft/linux-next-master/build/next-20221107/te… https://qa-reports.linaro.org/lkft/linux-next-master/build/next-20221107/te… metadata: git_ref: master git_repo: https://gitlab.com/Linaro/lkft/mirrors/next/linux-next git_sha: d8e87774068af213ab5b058b1b114dc397b577aa git_describe: next-20221107 kernel_version: 6.1.0-rc3 kernel-config: https://builds.tuxbuild.com/2HChVOSNxUpvfAfLTnaK7zyTdUi/config build-url: https://gitlab.com/Linaro/lkft/mirrors/next/linux-next/-/pipelines/687092361 artifact-location: https://builds.tuxbuild.com/2HChVOSNxUpvfAfLTnaK7zyTdUi toolchain: gcc-11 -- Linaro LKFT https://lkft.linaro.org

1 year, 3 months

3
3
0 0

[syzbot] WARNING in btrfs_free_reserved_data_space_noquota

by syzbot

Hello, syzbot found the following issue on: HEAD commit: b7b275e60bcd Linux 6.1-rc7 git tree: upstream console+strace: https://syzkaller.appspot.com/x/log.txt?x=158a7b73880000 kernel config: https://syzkaller.appspot.com/x/.config?x=2325e409a9a893e1 dashboard link: https://syzkaller.appspot.com/bug?extid=adec8406ad17413d4c06 compiler: Debian clang version 13.0.1-++20220126092033+75e33f71c2da-1~exp1~20220126212112.63, GNU ld (GNU Binutils for Debian) 2.35.2 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=169ccb75880000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17bf7153880000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/525233126d34/disk-b7b275e6.raw… vmlinux: https://storage.googleapis.com/syzbot-assets/e8299bf41400/vmlinux-b7b275e6.… kernel image: https://storage.googleapis.com/syzbot-assets/eebf691dbf6f/bzImage-b7b275e6.… mounted in repro: https://storage.googleapis.com/syzbot-assets/5423c2d2ad62/mount_0.gz The issue was bisected to: commit c814bf958926ff45a9c1e899bd001006ab6cfbae Author: ye xingchen <ye.xingchen(a)zte.com.cn> Date: Tue Aug 16 10:51:06 2022 +0000 powerpc/selftests: Use timersub() for gettimeofday() bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=118c3d03880000 final oops: https://syzkaller.appspot.com/x/report.txt?x=138c3d03880000 console output: https://syzkaller.appspot.com/x/log.txt?x=158c3d03880000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+adec8406ad17413d4c06(a)syzkaller.appspotmail.com Fixes: c814bf958926 ("powerpc/selftests: Use timersub() for gettimeofday()") RDX: 0000000000000001 RSI: 0000000020000280 RDI: 0000000000000005 RBP: 00007ffd32e91c70 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000008000000 R11: 0000000000000246 R12: 0000000000000006 R13: 00007ffd32e91cb0 R14: 00007ffd32e91c90 R15: 0000000000000006 </TASK> ------------[ cut here ]------------ WARNING: CPU: 1 PID: 3764 at fs/btrfs/space-info.h:122 btrfs_space_info_free_bytes_may_use fs/btrfs/space-info.h:154 [inline] WARNING: CPU: 1 PID: 3764 at fs/btrfs/space-info.h:122 btrfs_free_reserved_data_space_noquota+0x219/0x2b0 fs/btrfs/delalloc-space.c:179 Modules linked in: CPU: 1 PID: 3764 Comm: syz-executor759 Not tainted 6.1.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 RIP: 0010:btrfs_space_info_update_bytes_may_use fs/btrfs/space-info.h:122 [inline] RIP: 0010:btrfs_space_info_free_bytes_may_use fs/btrfs/space-info.h:154 [inline] RIP: 0010:btrfs_free_reserved_data_space_noquota+0x219/0x2b0 fs/btrfs/delalloc-space.c:179 Code: 2f 00 74 08 4c 89 ef e8 b5 98 32 fe 49 8b 5d 00 48 89 df 4c 8b 74 24 08 4c 89 f6 e8 21 81 de fd 4c 39 f3 73 16 e8 d7 7e de fd <0f> 0b 31 db 4c 8b 34 24 41 80 3c 2f 00 75 8c eb 92 e8 c1 7e de fd RSP: 0018:ffffc9000443f410 EFLAGS: 00010293 RAX: ffffffff83ac1919 RBX: 00000000005cb000 RCX: ffff888027989d40 RDX: 0000000000000000 RSI: 0000000000800000 RDI: 00000000005cb000 RBP: dffffc0000000000 R08: ffffffff83ac190f R09: fffffbfff1cebe0e R10: fffffbfff1cebe0e R11: 1ffffffff1cebe0d R12: ffff8880774f3800 R13: ffff8880774f3860 R14: 0000000000800000 R15: 1ffff1100ee9e70c FS: 0000555555aaa300(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0d98f20140 CR3: 0000000025ccf000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> btrfs_free_reserved_data_space+0x9d/0xd0 fs/btrfs/delalloc-space.c:199 btrfs_dio_iomap_begin+0x8f7/0x1070 fs/btrfs/inode.c:7762 iomap_iter+0x606/0x8a0 fs/iomap/iter.c:74 __iomap_dio_rw+0xd91/0x20d0 fs/iomap/direct-io.c:601 btrfs_dio_write+0x9c/0xe0 fs/btrfs/inode.c:8094 btrfs_direct_write fs/btrfs/file.c:1835 [inline] btrfs_do_write_iter+0x871/0x1260 fs/btrfs/file.c:1980 do_iter_write+0x6c2/0xc20 fs/read_write.c:861 vfs_writev fs/read_write.c:934 [inline] do_pwritev+0x200/0x350 fs/read_write.c:1031 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f0d98ea8ea9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 41 15 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffd32e91c38 EFLAGS: 00000246 ORIG_RAX: 0000000000000148 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f0d98ea8ea9 RDX: 0000000000000001 RSI: 0000000020000280 RDI: 0000000000000005 RBP: 00007ffd32e91c70 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000008000000 R11: 0000000000000246 R12: 0000000000000006 R13: 00007ffd32e91cb0 R14: 00007ffd32e91c90 R15: 0000000000000006 </TASK> --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller(a)googlegroups.com. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. For information about bisection process see: https://goo.gl/tpsmEJ#bisection syzbot can test patches for this issue, for details see: https://goo.gl/tpsmEJ#testing-patches

1 year, 3 months

3
3
0 0

[PATCH v6] lib: add basic KUnit test for lib/math

by Daniel Latypov

Add basic test coverage for files that don't require any config options: * part of math.h (what seem to be the most commonly used macros) * gcd.c * lcm.c * int_sqrt.c * reciprocal_div.c (Ignored int_pow.c since it's a simple textbook algorithm.) These tests aren't particularly interesting, but they * provide short and simple examples of parameterized tests * provide a place to add tests for any new files in this dir * are written so adding new test cases to cover edge cases should be easy * looking at code coverage, we hit all the branches in the .c files Signed-off-by: Daniel Latypov <dlatypov(a)google.com> Reviewed-by: David Gow <davidgow(a)google.com> --- Changes since v5: * add in test cases for roundup/rounddown * address misc comments from David Changes since v4: * add in test cases for some math.h macros (abs, round_up/round_down, div_round_down/closest) * use parameterized testing less to keep things terser Changes since v3: * fix `checkpatch.pl --strict` warnings * add test cases for gcd(0,0) and lcm(0,0) * minor: don't test both gcd(a,b) and gcd(b,a) when a == b Changes since v2: mv math_test.c => math_kunit.c Changes since v1: * Rebase and rewrite to use the new parameterized testing support. * misc: fix overflow in literal and inline int_sqrt format string. * related: commit 1f0e943df68a ("Documentation: kunit: provide guidance for testing many inputs") was merged explaining the patterns shown here. * there's an in-flight patch to update it for parameterized testing. --- lib/math/Kconfig | 12 ++ lib/math/Makefile | 2 + lib/math/math_kunit.c | 291 ++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 305 insertions(+) create mode 100644 lib/math/math_kunit.c diff --git a/lib/math/Kconfig b/lib/math/Kconfig index f19bc9734fa7..a974d4db0f9c 100644 --- a/lib/math/Kconfig +++ b/lib/math/Kconfig @@ -15,3 +15,15 @@ config PRIME_NUMBERS config RATIONAL bool + +config MATH_KUNIT_TEST + tristate "KUnit test for lib/math and math.h" if !KUNIT_ALL_TESTS + depends on KUNIT + default KUNIT_ALL_TESTS + help + This builds unit tests for lib/math and math.h. + + For more information on KUnit and unit tests in general, please refer + to the KUnit documentation in Documentation/dev-tools/kunit/. + + If unsure, say N. diff --git a/lib/math/Makefile b/lib/math/Makefile index be6909e943bd..30abb7a8d564 100644 --- a/lib/math/Makefile +++ b/lib/math/Makefile @@ -4,3 +4,5 @@ obj-y += div64.o gcd.o lcm.o int_pow.o int_sqrt.o reciprocal_div.o obj-$(CONFIG_CORDIC) += cordic.o obj-$(CONFIG_PRIME_NUMBERS) += prime_numbers.o obj-$(CONFIG_RATIONAL) += rational.o + +obj-$(CONFIG_MATH_KUNIT_TEST) += math_kunit.o diff --git a/lib/math/math_kunit.c b/lib/math/math_kunit.c new file mode 100644 index 000000000000..556c23b17c3c --- /dev/null +++ b/lib/math/math_kunit.c @@ -0,0 +1,291 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Simple KUnit suite for math helper funcs that are always enabled. + * + * Copyright (C) 2020, Google LLC. + * Author: Daniel Latypov <dlatypov(a)google.com> + */ + +#include <kunit/test.h> +#include <linux/gcd.h> +#include <linux/kernel.h> +#include <linux/lcm.h> +#include <linux/reciprocal_div.h> + +static void abs_test(struct kunit *test) +{ + KUNIT_EXPECT_EQ(test, abs((char)0), (char)0); + KUNIT_EXPECT_EQ(test, abs((char)42), (char)42); + KUNIT_EXPECT_EQ(test, abs((char)-42), (char)42); + + /* The expression in the macro is actually promoted to an int. */ + KUNIT_EXPECT_EQ(test, abs((short)0), 0); + KUNIT_EXPECT_EQ(test, abs((short)42), 42); + KUNIT_EXPECT_EQ(test, abs((short)-42), 42); + + KUNIT_EXPECT_EQ(test, abs(0), 0); + KUNIT_EXPECT_EQ(test, abs(42), 42); + KUNIT_EXPECT_EQ(test, abs(-42), 42); + + KUNIT_EXPECT_EQ(test, abs(0L), 0L); + KUNIT_EXPECT_EQ(test, abs(42L), 42L); + KUNIT_EXPECT_EQ(test, abs(-42L), 42L); + + KUNIT_EXPECT_EQ(test, abs(0LL), 0LL); + KUNIT_EXPECT_EQ(test, abs(42LL), 42LL); + KUNIT_EXPECT_EQ(test, abs(-42LL), 42LL); + + /* Unsigned types get casted to signed. */ + KUNIT_EXPECT_EQ(test, abs(0ULL), 0LL); + KUNIT_EXPECT_EQ(test, abs(42ULL), 42LL); +} + +static void int_sqrt_test(struct kunit *test) +{ + KUNIT_EXPECT_EQ(test, int_sqrt(0UL), 0UL); + KUNIT_EXPECT_EQ(test, int_sqrt(1UL), 1UL); + KUNIT_EXPECT_EQ(test, int_sqrt(4UL), 2UL); + KUNIT_EXPECT_EQ(test, int_sqrt(5UL), 2UL); + KUNIT_EXPECT_EQ(test, int_sqrt(8UL), 2UL); + KUNIT_EXPECT_EQ(test, int_sqrt(1UL << 30), 1UL << 15); +} + +static void round_up_test(struct kunit *test) +{ + KUNIT_EXPECT_EQ(test, round_up(0, 1), 0); + KUNIT_EXPECT_EQ(test, round_up(1, 2), 2); + KUNIT_EXPECT_EQ(test, round_up(3, 2), 4); + KUNIT_EXPECT_EQ(test, round_up((1 << 30) - 1, 2), 1 << 30); + KUNIT_EXPECT_EQ(test, round_up((1 << 30) - 1, 1 << 29), 1 << 30); +} + +static void round_down_test(struct kunit *test) +{ + KUNIT_EXPECT_EQ(test, round_down(0, 1), 0); + KUNIT_EXPECT_EQ(test, round_down(1, 2), 0); + KUNIT_EXPECT_EQ(test, round_down(3, 2), 2); + KUNIT_EXPECT_EQ(test, round_down((1 << 30) - 1, 2), (1 << 30) - 2); + KUNIT_EXPECT_EQ(test, round_down((1 << 30) - 1, 1 << 29), 1 << 29); +} + +/* These versions can round to numbers that aren't a power of two */ +static void roundup_test(struct kunit *test) +{ + KUNIT_EXPECT_EQ(test, roundup(0, 1), 0); + KUNIT_EXPECT_EQ(test, roundup(1, 2), 2); + KUNIT_EXPECT_EQ(test, roundup(3, 2), 4); + KUNIT_EXPECT_EQ(test, roundup((1 << 30) - 1, 2), 1 << 30); + KUNIT_EXPECT_EQ(test, roundup((1 << 30) - 1, 1 << 29), 1 << 30); + + KUNIT_EXPECT_EQ(test, roundup(3, 2), 4); + KUNIT_EXPECT_EQ(test, roundup(4, 3), 6); +} + +static void rounddown_test(struct kunit *test) +{ + KUNIT_EXPECT_EQ(test, rounddown(0, 1), 0); + KUNIT_EXPECT_EQ(test, rounddown(1, 2), 0); + KUNIT_EXPECT_EQ(test, rounddown(3, 2), 2); + KUNIT_EXPECT_EQ(test, rounddown((1 << 30) - 1, 2), (1 << 30) - 2); + KUNIT_EXPECT_EQ(test, rounddown((1 << 30) - 1, 1 << 29), 1 << 29); + + KUNIT_EXPECT_EQ(test, rounddown(3, 2), 2); + KUNIT_EXPECT_EQ(test, rounddown(4, 3), 3); +} + +static void div_round_up_test(struct kunit *test) +{ + KUNIT_EXPECT_EQ(test, DIV_ROUND_UP(0, 1), 0); + KUNIT_EXPECT_EQ(test, DIV_ROUND_UP(20, 10), 2); + KUNIT_EXPECT_EQ(test, DIV_ROUND_UP(21, 10), 3); + KUNIT_EXPECT_EQ(test, DIV_ROUND_UP(21, 20), 2); + KUNIT_EXPECT_EQ(test, DIV_ROUND_UP(21, 99), 1); +} + +static void div_round_closest_test(struct kunit *test) +{ + KUNIT_EXPECT_EQ(test, DIV_ROUND_CLOSEST(0, 1), 0); + KUNIT_EXPECT_EQ(test, DIV_ROUND_CLOSEST(20, 10), 2); + KUNIT_EXPECT_EQ(test, DIV_ROUND_CLOSEST(21, 10), 2); + KUNIT_EXPECT_EQ(test, DIV_ROUND_CLOSEST(25, 10), 3); +} + +/* Generic test case for unsigned long inputs. */ +struct test_case { + unsigned long a, b; + unsigned long result; +}; + +static struct test_case gcd_cases[] = { + { + .a = 0, .b = 0, + .result = 0, + }, + { + .a = 0, .b = 1, + .result = 1, + }, + { + .a = 2, .b = 2, + .result = 2, + }, + { + .a = 2, .b = 4, + .result = 2, + }, + { + .a = 3, .b = 5, + .result = 1, + }, + { + .a = 3 * 9, .b = 3 * 5, + .result = 3, + }, + { + .a = 3 * 5 * 7, .b = 3 * 5 * 11, + .result = 15, + }, + { + .a = 1 << 21, + .b = (1 << 21) - 1, + .result = 1, + }, +}; + +KUNIT_ARRAY_PARAM(gcd, gcd_cases, NULL); + +static void gcd_test(struct kunit *test) +{ + const char *message_fmt = "gcd(%lu, %lu)"; + const struct test_case *test_param = test->param_value; + + KUNIT_EXPECT_EQ_MSG(test, test_param->result, + gcd(test_param->a, test_param->b), + message_fmt, test_param->a, + test_param->b); + + if (test_param->a == test_param->b) + return; + + /* gcd(a,b) == gcd(b,a) */ + KUNIT_EXPECT_EQ_MSG(test, test_param->result, + gcd(test_param->b, test_param->a), + message_fmt, test_param->b, + test_param->a); +} + +static struct test_case lcm_cases[] = { + { + .a = 0, .b = 0, + .result = 0, + }, + { + .a = 0, .b = 1, + .result = 0, + }, + { + .a = 1, .b = 2, + .result = 2, + }, + { + .a = 2, .b = 2, + .result = 2, + }, + { + .a = 3 * 5, .b = 3 * 7, + .result = 3 * 5 * 7, + }, +}; + +KUNIT_ARRAY_PARAM(lcm, lcm_cases, NULL); + +static void lcm_test(struct kunit *test) +{ + const char *message_fmt = "lcm(%lu, %lu)"; + const struct test_case *test_param = test->param_value; + + KUNIT_EXPECT_EQ_MSG(test, test_param->result, + lcm(test_param->a, test_param->b), + message_fmt, test_param->a, + test_param->b); + + if (test_param->a == test_param->b) + return; + + /* lcm(a,b) == lcm(b,a) */ + KUNIT_EXPECT_EQ_MSG(test, test_param->result, + lcm(test_param->b, test_param->a), + message_fmt, test_param->b, + test_param->a); +} + +struct u32_test_case { + u32 a, b; + u32 result; +}; + +static struct u32_test_case reciprocal_div_cases[] = { + { + .a = 0, .b = 1, + .result = 0, + }, + { + .a = 42, .b = 20, + .result = 2, + }, + { + .a = 42, .b = 9999, + .result = 0, + }, + { + .a = (1 << 16), .b = (1 << 14), + .result = 1 << 2, + }, +}; + +KUNIT_ARRAY_PARAM(reciprocal_div, reciprocal_div_cases, NULL); + +static void reciprocal_div_test(struct kunit *test) +{ + const struct u32_test_case *test_param = test->param_value; + struct reciprocal_value rv = reciprocal_value(test_param->b); + + KUNIT_EXPECT_EQ_MSG(test, test_param->result, + reciprocal_divide(test_param->a, rv), + "reciprocal_divide(%u, %u)", + test_param->a, test_param->b); +} + +static void reciprocal_scale_test(struct kunit *test) +{ + KUNIT_EXPECT_EQ(test, reciprocal_scale(0u, 100), 0u); + KUNIT_EXPECT_EQ(test, reciprocal_scale(1u, 100), 0u); + KUNIT_EXPECT_EQ(test, reciprocal_scale(1u << 4, 1 << 28), 1u); + KUNIT_EXPECT_EQ(test, reciprocal_scale(1u << 16, 1 << 28), 1u << 12); + KUNIT_EXPECT_EQ(test, reciprocal_scale(~0u, 1 << 28), (1u << 28) - 1); +} + +static struct kunit_case math_test_cases[] = { + KUNIT_CASE(abs_test), + KUNIT_CASE(int_sqrt_test), + KUNIT_CASE(round_up_test), + KUNIT_CASE(round_down_test), + KUNIT_CASE(roundup_test), + KUNIT_CASE(rounddown_test), + KUNIT_CASE(div_round_up_test), + KUNIT_CASE(div_round_closest_test), + KUNIT_CASE_PARAM(gcd_test, gcd_gen_params), + KUNIT_CASE_PARAM(lcm_test, lcm_gen_params), + KUNIT_CASE_PARAM(reciprocal_div_test, reciprocal_div_gen_params), + KUNIT_CASE(reciprocal_scale_test), + {} +}; + +static struct kunit_suite math_test_suite = { + .name = "lib-math", + .test_cases = math_test_cases, +}; + +kunit_test_suites(&math_test_suite); + +MODULE_LICENSE("GPL v2"); base-commit: 7e25f40eab52c57ff6772d27d2aef3640a3237d7 -- 2.31.1.368.gbe11c130af-goog

1 year, 3 months

5
5
0 0

[PATCH v6 1/2] posix-timers: Prefer delivery of signals to the current thread

by Marco Elver

From: Dmitry Vyukov <dvyukov(a)google.com> POSIX timers using the CLOCK_PROCESS_CPUTIME_ID clock prefer the main thread of a thread group for signal delivery. However, this has a significant downside: it requires waking up a potentially idle thread. Instead, prefer to deliver signals to the current thread (in the same thread group) if SIGEV_THREAD_ID is not set by the user. This does not change guaranteed semantics, since POSIX process CPU time timers have never guaranteed that signal delivery is to a specific thread (without SIGEV_THREAD_ID set). The effect is that we no longer wake up potentially idle threads, and the kernel is no longer biased towards delivering the timer signal to any particular thread (which better distributes the timer signals esp. when multiple timers fire concurrently). Signed-off-by: Dmitry Vyukov <dvyukov(a)google.com> Suggested-by: Oleg Nesterov <oleg(a)redhat.com> Reviewed-by: Oleg Nesterov <oleg(a)redhat.com> Signed-off-by: Marco Elver <elver(a)google.com> --- v6: - Split test from this patch. - Update wording on what this patch aims to improve. v5: - Rebased onto v6.2. v4: - Restructured checks in send_sigqueue() as suggested. v3: - Switched to the completely different implementation (much simpler) based on the Oleg's idea. RFC v2: - Added additional Cc as Thomas asked. --- kernel/signal.c | 25 ++++++++++++++++++++++--- 1 file changed, 22 insertions(+), 3 deletions(-) diff --git a/kernel/signal.c b/kernel/signal.c index 8cb28f1df294..605445fa27d4 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -1003,8 +1003,7 @@ static void complete_signal(int sig, struct task_struct *p, enum pid_type type) /* * Now find a thread we can wake up to take the signal off the queue. * - * If the main thread wants the signal, it gets first crack. - * Probably the least surprising to the average bear. + * Try the suggested task first (may or may not be the main thread). */ if (wants_signal(sig, p)) t = p; @@ -1970,8 +1969,23 @@ int send_sigqueue(struct sigqueue *q, struct pid *pid, enum pid_type type) ret = -1; rcu_read_lock(); + /* + * This function is used by POSIX timers to deliver a timer signal. + * Where type is PIDTYPE_PID (such as for timers with SIGEV_THREAD_ID + * set), the signal must be delivered to the specific thread (queues + * into t->pending). + * + * Where type is not PIDTYPE_PID, signals must just be delivered to the + * current process. In this case, prefer to deliver to current if it is + * in the same thread group as the target, as it avoids unnecessarily + * waking up a potentially idle task. + */ t = pid_task(pid, type); - if (!t || !likely(lock_task_sighand(t, &flags))) + if (!t) + goto ret; + if (type != PIDTYPE_PID && same_thread_group(t, current)) + t = current; + if (!likely(lock_task_sighand(t, &flags))) goto ret; ret = 1; /* the signal is ignored */ @@ -1993,6 +2007,11 @@ int send_sigqueue(struct sigqueue *q, struct pid *pid, enum pid_type type) q->info.si_overrun = 0; signalfd_notify(t, sig); + /* + * If the type is not PIDTYPE_PID, we just use shared_pending, which + * won't guarantee that the specified task will receive the signal, but + * is sufficient if t==current in the common case. + */ pending = (type != PIDTYPE_PID) ? &t->signal->shared_pending : &t->pending; list_add_tail(&q->list, &pending->list); sigaddset(&pending->signal, sig); -- 2.40.0.rc1.284.g88254d51c5-goog

1 year, 4 months

9
50
0 0

[PATCH v3] selftests/ftrace: traceonoff_triggers: strip off names

by Yipeng Zou

The func_traceonoff_triggers.tc sometimes goes to fail on my board, Kunpeng-920. [root@localhost]# ./ftracetest ./test.d/ftrace/func_traceonoff_triggers.tc -l fail.log === Ftrace unit tests === [1] ftrace - test for function traceon/off triggers [FAIL] [2] (instance) ftrace - test for function traceon/off triggers [UNSUPPORTED] I look up the log, and it shows that the md5sum is different between csum1 and csum2. ++ cnt=611 ++ sleep .1 +++ cnt_trace +++ grep -v '^#' trace +++ wc -l ++ cnt2=611 ++ '[' 611 -ne 611 ']' +++ cat tracing_on ++ on=0 ++ '[' 0 '!=' 0 ']' +++ md5sum trace ++ csum1='76896aa74362fff66a6a5f3cf8a8a500 trace' ++ sleep .1 +++ md5sum trace ++ csum2='ee8625a21c058818fc26e45c1ed3f6de trace' ++ '[' '76896aa74362fff66a6a5f3cf8a8a500 trace' '!=' 'ee8625a21c058818fc26e45c1ed3f6de trace' ']' ++ fail 'Tracing file is still changing' ++ echo Tracing file is still changing Tracing file is still changing ++ exit_fail ++ exit 1 So I directly dump the trace file before md5sum, the diff shows that: [root@localhost]# diff trace_1.log trace_2.log -y --suppress-common-lines dockerd-12285 [036] d.... 18385.510290: sched_stat | <...>-12285 [036] d.... 18385.510290: sched_stat dockerd-12285 [036] d.... 18385.510291: sched_swit | <...>-12285 [036] d.... 18385.510291: sched_swit <...>-740 [044] d.... 18385.602859: sched_stat | kworker/44:1-740 [044] d.... 18385.602859: sched_stat <...>-740 [044] d.... 18385.602860: sched_swit | kworker/44:1-740 [044] d.... 18385.602860: sched_swit And we can see that <...> filed be filled with names. We can strip off the names there to fix that. After strip off the names: kworker/u257:0-12 [019] d..2. 2528.758910: sched_stat | -12 [019] d..2. 2528.758910: sched_stat_runtime: comm=k kworker/u257:0-12 [019] d..2. 2528.758912: sched_swit | -12 [019] d..2. 2528.758912: sched_switch: prev_comm=kw <idle>-0 [000] d.s5. 2528.762318: sched_waki | -0 [000] d.s5. 2528.762318: sched_waking: comm=sshd pi <idle>-0 [037] dNh2. 2528.762326: sched_wake | -0 [037] dNh2. 2528.762326: sched_wakeup: comm=sshd pi <idle>-0 [037] d..2. 2528.762334: sched_swit | -0 [037] d..2. 2528.762334: sched_switch: prev_comm=sw Fixes: d87b29179aa0 ("selftests: ftrace: Use md5sum to take less time of checking logs") Suggested-by: Steven Rostedt (Google) <rostedt(a)goodmis.org> Signed-off-by: Yipeng Zou <zouyipeng(a)huawei.com> Acked-by: Masami Hiramatsu (Google) <mhiramat(a)kernel.org> Reviewed-by: Steven Rostedt (Google) <rostedt(a)goodmis.org> --- .../ftrace/test.d/ftrace/func_traceonoff_triggers.tc | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/ftrace/test.d/ftrace/func_traceonoff_triggers.tc b/tools/testing/selftests/ftrace/test.d/ftrace/func_traceonoff_triggers.tc index aee22289536b..1b57771dbfdf 100644 --- a/tools/testing/selftests/ftrace/test.d/ftrace/func_traceonoff_triggers.tc +++ b/tools/testing/selftests/ftrace/test.d/ftrace/func_traceonoff_triggers.tc @@ -90,9 +90,10 @@ if [ $on != "0" ]; then fail "Tracing is not off" fi -csum1=`md5sum trace` +# Cannot rely on names being around as they are only cached, strip them +csum1=`cat trace | sed -e 's/^ *[^ ]*$-[0-9][0-9]*$/\1/' | md5sum` sleep $SLEEP_TIME -csum2=`md5sum trace` +csum2=`cat trace | sed -e 's/^ *[^ ]*$-[0-9][0-9]*$/\1/' | md5sum` if [ "$csum1" != "$csum2" ]; then fail "Tracing file is still changing" -- 2.34.1

1 year, 4 months

2
2
0 0

[PATCH v2] selftests: sud_test: return correct emulated syscall value on RISC-V

by Clément Léger

Currently, the sud_test expects the emulated syscall to return the emulated syscall number. This assumption only works on architectures were the syscall calling convention use the same register for syscall number/syscall return value. This is not the case for RISC-V and thus the return value must be also emulated using the provided ucontext. Signed-off-by: Clément Léger <cleger(a)rivosinc.com> Reviewed-by: Palmer Dabbelt <palmer(a)rivosinc.com> Acked-by: Palmer Dabbelt <palmer(a)rivosinc.com> --- Changes in V2: - Changes comment to be more explicit - Use A7 syscall arg rather than hardcoding MAGIC_SYSCALL_1 --- .../selftests/syscall_user_dispatch/sud_test.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/tools/testing/selftests/syscall_user_dispatch/sud_test.c b/tools/testing/selftests/syscall_user_dispatch/sud_test.c index b5d592d4099e..d975a6767329 100644 --- a/tools/testing/selftests/syscall_user_dispatch/sud_test.c +++ b/tools/testing/selftests/syscall_user_dispatch/sud_test.c @@ -158,6 +158,20 @@ static void handle_sigsys(int sig, siginfo_t *info, void *ucontext) /* In preparation for sigreturn. */ SYSCALL_DISPATCH_OFF(glob_sel); + + /* + * The tests for argument handling assume that `syscall(x) == x`. This + * is a NOP on x86 because the syscall number is passed in %rax, which + * happens to also be the function ABI return register. Other + * architectures may need to swizzle the arguments around. + */ +#if defined(__riscv) +/* REG_A7 is not defined in libc headers */ +# define REG_A7 (REG_A0 + 7) + + ((ucontext_t *)ucontext)->uc_mcontext.__gregs[REG_A0] = + ((ucontext_t *)ucontext)->uc_mcontext.__gregs[REG_A7]; +#endif } TEST(dispatch_and_return) -- 2.43.0

1 year, 4 months

3
2
0 0

[PATCH] KVM: selftests: Use TAP in the steal_time test

by Thomas Huth

For easier use of the tests in automation and for having some status information for the user while the test is running, let's provide some TAP output in this test. Signed-off-by: Thomas Huth <thuth(a)redhat.com> --- NB: This patch does not use the interface from kselftest_harness.h since it is not very suitable for the for-loop in this patch. tools/testing/selftests/kvm/steal_time.c | 46 ++++++++++++------------ 1 file changed, 23 insertions(+), 23 deletions(-) diff --git a/tools/testing/selftests/kvm/steal_time.c b/tools/testing/selftests/kvm/steal_time.c index 171adfb2a6cb..aa6149eb9ea1 100644 --- a/tools/testing/selftests/kvm/steal_time.c +++ b/tools/testing/selftests/kvm/steal_time.c @@ -81,20 +81,18 @@ static void steal_time_init(struct kvm_vcpu *vcpu, uint32_t i) static void steal_time_dump(struct kvm_vm *vm, uint32_t vcpu_idx) { struct kvm_steal_time *st = addr_gva2hva(vm, (ulong)st_gva[vcpu_idx]); - int i; - pr_info("VCPU%d:\n", vcpu_idx); - pr_info(" steal: %lld\n", st->steal); - pr_info(" version: %d\n", st->version); - pr_info(" flags: %d\n", st->flags); - pr_info(" preempted: %d\n", st->preempted); - pr_info(" u8_pad: "); - for (i = 0; i < 3; ++i) - pr_info("%d", st->u8_pad[i]); - pr_info("\n pad: "); - for (i = 0; i < 11; ++i) - pr_info("%d", st->pad[i]); - pr_info("\n"); + ksft_print_msg("VCPU%d:\n", vcpu_idx); + ksft_print_msg(" steal: %lld\n", st->steal); + ksft_print_msg(" version: %d\n", st->version); + ksft_print_msg(" flags: %d\n", st->flags); + ksft_print_msg(" preempted: %d\n", st->preempted); + ksft_print_msg(" u8_pad: %d %d %d\n", + st->u8_pad[0], st->u8_pad[1], st->u8_pad[2]); + ksft_print_msg(" pad: %d %d %d %d %d %d %d %d %d %d %d\n", + st->pad[0], st->pad[1], st->pad[2], st->pad[3], + st->pad[4], st->pad[5], st->pad[6], st->pad[7], + st->pad[8], st->pad[9], st->pad[10]); } #elif defined(__aarch64__) @@ -197,10 +195,10 @@ static void steal_time_dump(struct kvm_vm *vm, uint32_t vcpu_idx) { struct st_time *st = addr_gva2hva(vm, (ulong)st_gva[vcpu_idx]); - pr_info("VCPU%d:\n", vcpu_idx); - pr_info(" rev: %d\n", st->rev); - pr_info(" attr: %d\n", st->attr); - pr_info(" st_time: %ld\n", st->st_time); + ksft_print_msg("VCPU%d:\n", vcpu_idx); + ksft_print_msg(" rev: %d\n", st->rev); + ksft_print_msg(" attr: %d\n", st->attr); + ksft_print_msg(" st_time: %ld\n", st->st_time); } #endif @@ -267,7 +265,9 @@ int main(int ac, char **av) vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, ST_GPA_BASE, 1, gpages, 0); virt_map(vm, ST_GPA_BASE, ST_GPA_BASE, gpages); + ksft_print_header(); TEST_REQUIRE(is_steal_time_supported(vcpus[0])); + ksft_set_plan(NR_VCPUS); /* Run test on each VCPU */ for (i = 0; i < NR_VCPUS; ++i) { @@ -308,14 +308,14 @@ int main(int ac, char **av) run_delay, stolen_time); if (verbose) { - pr_info("VCPU%d: total-stolen-time=%ld test-stolen-time=%ld", i, - guest_stolen_time[i], stolen_time); - if (stolen_time == run_delay) - pr_info(" (BONUS: guest test-stolen-time even exactly matches test-run_delay)"); - pr_info("\n"); + ksft_print_msg("VCPU%d: total-stolen-time=%ld test-stolen-time=%ld%s\n", + i, guest_stolen_time[i], stolen_time, + stolen_time == run_delay ? + " (BONUS: guest test-stolen-time even exactly matches test-run_delay)" : ""); steal_time_dump(vm, i); } + ksft_test_result_pass("vcpu%d\n", i); } - return 0; + ksft_finished(); /* Print results and exit() accordingly */ } -- 2.41.0

1 year, 4 months

5
6
0 0

[PATCH 0/8] iommufd support pasid attach/replace

by Yi Liu

PASID (Process Address Space ID) is a PCIe extension to tag the DMA transactions out of a physical device, and most modern IOMMU hardware have supported PASID granular address translation. So a PASID-capable device can be attached to multiple hwpts (a.k.a. domains), each attachment is tagged with a pasid. This series first adds a missing iommu API to replace domain for a pasid, then adds iommufd APIs for device drivers to attach/replace/detach pasid to/from hwpt per userspace's request, and adds selftest to validate the iommufd APIs. pasid attach/replace is mandatory on Intel VT-d given the PASID table locates in the physical address space hence must be managed by the kernel, both for supporting vSVA and coming SIOV. But it's optional on ARM/AMD which allow configuring the PASID/CD table either in host physical address space or nested on top of an GPA address space. This series only add VT-d support as the minimal requirement. Complete code can be found in below link: https://github.com/yiliu1765/iommufd/tree/iommufd_pasid Change log: v1: - Implemnet iommu_replace_device_pasid() to fall back to the original domain if this replacement failed (Kevin) - Add check in do_attach() to check corressponding attach_fn per the pasid value. rfc: https://lore.kernel.org/linux-iommu/20230926092651.17041-1-yi.l.liu@intel.c… Regards, Yi Liu Kevin Tian (1): iommufd: Support attach/replace hwpt per pasid Lu Baolu (2): iommu: Introduce a replace API for device pasid iommu/vt-d: Add set_dev_pasid callback for nested domain Yi Liu (5): iommufd: replace attach_fn with a structure iommufd/selftest: Add set_dev_pasid and remove_dev_pasid in mock iommu iommufd/selftest: Add a helper to get test device iommufd/selftest: Add test ops to test pasid attach/detach iommufd/selftest: Add coverage for iommufd pasid attach/detach drivers/iommu/intel/nested.c | 47 +++++ drivers/iommu/iommu-priv.h | 2 + drivers/iommu/iommu.c | 82 ++++++-- drivers/iommu/iommufd/Makefile | 1 + drivers/iommu/iommufd/device.c | 50 +++-- drivers/iommu/iommufd/iommufd_private.h | 23 +++ drivers/iommu/iommufd/iommufd_test.h | 24 +++ drivers/iommu/iommufd/pasid.c | 138 ++++++++++++++ drivers/iommu/iommufd/selftest.c | 176 ++++++++++++++++-- include/linux/iommufd.h | 6 + tools/testing/selftests/iommu/iommufd.c | 172 +++++++++++++++++ .../selftests/iommu/iommufd_fail_nth.c | 28 ++- tools/testing/selftests/iommu/iommufd_utils.h | 78 ++++++++ 13 files changed, 785 insertions(+), 42 deletions(-) create mode 100644 drivers/iommu/iommufd/pasid.c -- 2.34.1

1 year, 5 months

5
35
0 0

2025

2024

2023

2022

2021

2020

2019

2018

2017

Linux-kselftest-mirror January 2024