June 2024 - Linux-kselftest-mirror

[PATCH] selftests: proc: remove unreached code and fix build warning

by Amer Al Shanawany

fix the following warning: proc-empty-vm.c:385:17: warning: ignoring return value of ‘write’ declared with attribute ‘warn_unused_result’ [-Wunused-result] 385 | write(1, buf, rv); | ^~~~~~~~~~~~~~~~~ Reported-by: kernel test robot <lkp(a)intel.com> Closes: https://lore.kernel.org/r/202404010211.ygidvMwa-lkp@intel.com/ Signed-off-by: Amer Al Shanawany <amer.shanawany(a)gmail.com> --- tools/testing/selftests/proc/proc-empty-vm.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/tools/testing/selftests/proc/proc-empty-vm.c b/tools/testing/selftests/proc/proc-empty-vm.c index 56198d4ca2bf..b3f898aab4ab 100644 --- a/tools/testing/selftests/proc/proc-empty-vm.c +++ b/tools/testing/selftests/proc/proc-empty-vm.c @@ -381,9 +381,6 @@ static int test_proc_pid_statm(pid_t pid) assert(rv >= 0); assert(rv <= sizeof(buf)); - if (0) { - write(1, buf, rv); - } const char *p = buf; const char *const end = p + rv; -- 2.43.0

1 year, 2 months

4
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[PATCH 0/5] Reorganize string-stream and assert tests

by Ivan Orlov

Currently, we can run string-stream and assertion tests only when they are built into the kernel (with config options = y), since some of the symbols (string-stream functions and functions from assert.c) are not exported into any of the namespaces, therefore they are not accessible for the modules. This patch series exports the required symbols into the KUnit namespace. Also, it makes the string-stream test a separate module and removes the log test stub from kunit-test since now we can access the string-stream symbols even if the test which uses it is built as a module. Additionally, this patch series merges the assertion test suite into the kunit-test, since assert.c (and all of the assertion formatting functions in it) is a part of the KUnit core. Ivan Orlov (5): kunit: string-stream: export non-static functions kunit: kunit-test: Remove stub for log tests kunit: string-stream-test: Make it a separate module kunit: assert: export non-static functions kunit: Merge assertion test into kunit-test.c lib/kunit/Kconfig | 8 + lib/kunit/Makefile | 7 +- lib/kunit/assert.c | 4 + lib/kunit/assert_test.c | 388 -------------------------------- lib/kunit/kunit-test.c | 397 +++++++++++++++++++++++++++++++-- lib/kunit/string-stream-test.c | 2 + lib/kunit/string-stream.c | 12 +- 7 files changed, 405 insertions(+), 413 deletions(-) delete mode 100644 lib/kunit/assert_test.c -- 2.34.1

1 year, 2 months

2
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[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
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[PATCH v2 0/2] Add test to distinguish between thread's signal mask and ucontext_t

by Dev Jain

This patch series is motivated by the following observation: Raise a signal, jump to signal handler. The ucontext_t structure dumped by kernel to userspace has a uc_sigmask field having the mask of blocked signals. If you run a fresh minimalistic program doing this, this field is empty, even if you block some signals while registering the handler with sigaction(). Here is what the man-pages have to say: sigaction(2): "sa_mask specifies a mask of signals which should be blocked (i.e., added to the signal mask of the thread in which the signal handler is invoked) during execution of the signal handler. In addition, the signal which triggered the handler will be blocked, unless the SA_NODEFER flag is used." signal(7): Under "Execution of signal handlers", (1.3) implies: "The thread's current signal mask is accessible via the ucontext_t object that is pointed to by the third argument of the signal handler." But, (1.4) states: "Any signals specified in act->sa_mask when registering the handler with sigprocmask(2) are added to the thread's signal mask. The signal being delivered is also added to the signal mask, unless SA_NODEFER was specified when registering the handler. These signals are thus blocked while the handler executes." There clearly is no distinction being made in the man pages between "Thread's signal mask" and ucontext_t; this logically should imply that a signal blocked by populating struct sigaction should be visible in ucontext_t. Here is what the kernel code does (for Aarch64): do_signal() -> handle_signal() -> sigmask_to_save(), which returns &current->blocked, is passed to setup_rt_frame() -> setup_sigframe() -> __copy_to_user(). Hence, &current->blocked is copied to ucontext_t exposed to userspace. Returning back to handle_signal(), signal_setup_done() -> signal_delivered() -> sigorsets() and set_current_blocked() are responsible for using information from struct ksignal ksig, which was populated through the sigaction() system call in kernel/signal.c: copy_from_user(&new_sa.sa, act, sizeof(new_sa.sa)), to update &current->blocked; hence, the set of blocked signals for the current thread is updated AFTER the kernel dumps ucontext_t to userspace. Assuming that the above is indeed the intended behaviour, because it semantically makes sense, since the signals blocked using sigaction() remain blocked only till the execution of the handler, and not in the context present before jumping to the handler (but nothing can be confirmed from the man-pages), the series introduces a test for mangling with uc_sigmask. I will send a separate series to fix the man-pages. The proposed selftest has been tested out on Aarch32, Aarch64 and x86_64. Changes in v2: - Replace all occurrences of SIGPIPE with SIGSEGV - Add a testcase: Raise the same signal again; it must not be queued - Remove unneeded <assert.h>, <unistd.h> - Give a detailed test description in the comments; also describe the exact meaning of delivered and blocked - Handle errors for all libc functions/syscalls - Mention tests in Makefile and .gitignore in alphabetical order Dev Jain (2): selftests: Rename sigaltstack to generic signal selftests: Add a test mangling with uc_sigmask tools/testing/selftests/Makefile | 2 +- .../{sigaltstack => signal}/.gitignore | 3 +- .../{sigaltstack => signal}/Makefile | 3 +- .../current_stack_pointer.h | 0 .../selftests/signal/mangle_uc_sigmask.c | 194 ++++++++++++++++++ .../sas.c => signal/sigaltstack.c} | 0 6 files changed, 199 insertions(+), 3 deletions(-) rename tools/testing/selftests/{sigaltstack => signal}/.gitignore (57%) rename tools/testing/selftests/{sigaltstack => signal}/Makefile (53%) rename tools/testing/selftests/{sigaltstack => signal}/current_stack_pointer.h (100%) create mode 100644 tools/testing/selftests/signal/mangle_uc_sigmask.c rename tools/testing/selftests/{sigaltstack/sas.c => signal/sigaltstack.c} (100%) -- 2.34.1

1 year, 2 months

1
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[PATCH v1 0/1] mm/memfd: add documentation for MFD_NOEXEC_SEAL

by jeffxu＠chromium.org

From: Jeff Xu <jeffxu(a)chromium.org> When MFD_NOEXEC_SEAL was introduced, there was one big mistake: it didn't have proper documentation. This led to a lot of confusion, especially about whether or not memfd created with the MFD_NOEXEC_SEAL flag is sealable. Before MFD_NOEXEC_SEAL, memfd had to explicitly set MFD_ALLOW_SEALING to be sealable, so it's a fair question. As one might have noticed, unlike other flags in memfd_create, MFD_NOEXEC_SEAL is actually a combination of multiple flags. The idea is to make it easier to use memfd in the most common way, which is NOEXEC + F_SEAL_EXEC + MFD_ALLOW_SEALING. This works with sysctl vm.noexec to help existing applications move to a more secure way of using memfd. Proposals have been made to put MFD_NOEXEC_SEAL non-sealable, unless MFD_ALLOW_SEALING is set, to be consistent with other flags [1] [2], Those are based on the viewpoint that each flag is an atomic unit, which is a reasonable assumption. However, MFD_NOEXEC_SEAL was designed with the intent of promoting the most secure method of using memfd, therefore a combination of multiple functionalities into one bit. Furthermore, the MFD_NOEXEC_SEAL has been added for more than one year, and multiple applications and distributions have backported and utilized it. Altering ABI now presents a degree of risk and may lead to disruption. MFD_NOEXEC_SEAL is a new flag, and applications must change their code to use it. There is no backward compatibility problem. When sysctl vm.noexec == 1 or 2, applications that don't set MFD_NOEXEC_SEAL or MFD_EXEC will get MFD_NOEXEC_SEAL memfd. And old-application might break, that is by-design, in such a system vm.noexec = 0 shall be used. Also no backward compatibility problem. I propose to include this documentation patch to assist in clarifying the semantics of MFD_NOEXEC_SEAL, thereby preventing any potential future confusion. This patch supersede previous patch which is trying different direction [3], and please remove [2] from mm-unstable branch when applying this patch. Finally, I would like to express my gratitude to David Rheinsberg and Barnabás Pőcze for initiating the discussion on the topic of sealability. [1] https://lore.kernel.org/lkml/20230714114753.170814-1-david@readahead.eu/ [2] https://lore.kernel.org/lkml/20240513191544.94754-1-pobrn@protonmail.com/ [3] https://lore.kernel.org/lkml/20240524033933.135049-1-jeffxu@google.com/ Jeff Xu (1): mm/memfd: add documentation for MFD_NOEXEC_SEAL MFD_EXEC Documentation/userspace-api/index.rst | 1 + Documentation/userspace-api/mfd_noexec.rst | 86 ++++++++++++++++++++++ 2 files changed, 87 insertions(+) create mode 100644 Documentation/userspace-api/mfd_noexec.rst -- 2.45.2.505.gda0bf45e8d-goog

1 year, 2 months

5
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[PATCH net 0/4] mptcp: various fixes

by Matthieu Baerts (NGI0)

The different patches here are some unrelated fixes for MPTCP: - Patch 1 ensures 'snd_una' is initialised on connect in case of MPTCP fallback to TCP followed by retransmissions before the processing of any other incoming packets. A fix for v5.9+. - Patch 2 makes sure the RmAddr MIB counter is incremented, and only once per ID, upon the reception of a RM_ADDR. A fix for v5.10+. - Patch 3 doesn't update 'add addr' related counters if the connect() was not possible. A fix for v5.7+. - Patch 4 updates the mailmap file to add Geliang's new email address. Signed-off-by: Matthieu Baerts (NGI0) <matttbe(a)kernel.org> --- Geliang Tang (1): mailmap: map Geliang's new email address Paolo Abeni (1): mptcp: ensure snd_una is properly initialized on connect YonglongLi (2): mptcp: pm: inc RmAddr MIB counter once per RM_ADDR ID mptcp: pm: update add_addr counters after connect .mailmap | 1 + net/mptcp/pm_netlink.c | 21 ++++++++++++++------- net/mptcp/protocol.c | 1 + tools/testing/selftests/net/mptcp/mptcp_join.sh | 5 +++-- 4 files changed, 19 insertions(+), 9 deletions(-) --- base-commit: c44711b78608c98a3e6b49ce91678cd0917d5349 change-id: 20240607-upstream-net-20240607-misc-fixes-024007171d60 Best regards, -- Matthieu Baerts (NGI0) <matttbe(a)kernel.org>

1 year, 2 months

2
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[PATCH bpf-next v2 0/2] Enable INET_XFRM_TUNNEL in config

by Geliang Tang

From: Geliang Tang <tanggeliang(a)kylinos.cn> v2: - resend patch 1. - another fix for test_tunnel. Geliang Tang (2): selftests/bpf: Enable INET_XFRM_TUNNEL in config selftests/bpf: Close netns in error paths in test_tunnel tools/testing/selftests/bpf/config | 4 +++ .../selftests/bpf/prog_tests/test_tunnel.c | 27 +++++++++++++------ 2 files changed, 23 insertions(+), 8 deletions(-) -- 2.43.0

1 year, 2 months

1
2
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[PATCH bpf-next] selftests/bpf: Enable INET_XFRM_TUNNEL in config

by Geliang Tang

From: Geliang Tang <tanggeliang(a)kylinos.cn> The kconfigs CONFIG_INET_XFRM_TUNNEL and CONFIG_INET6_XFRM_TUNNEL are needed by test_tunnel tests. This patch enables them together with the dependent kconfigs CONFIG_INET_IPCOMP and CONFIG_INET6_IPCOMP. Signed-off-by: Geliang Tang <tanggeliang(a)kylinos.cn> --- tools/testing/selftests/bpf/config | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/tools/testing/selftests/bpf/config b/tools/testing/selftests/bpf/config index eeabd798bc3a..8aa56e6bdac1 100644 --- a/tools/testing/selftests/bpf/config +++ b/tools/testing/selftests/bpf/config @@ -95,3 +95,7 @@ CONFIG_XDP_SOCKETS=y CONFIG_XFRM_INTERFACE=y CONFIG_TCP_CONG_DCTCP=y CONFIG_TCP_CONG_BBR=y +CONFIG_INET_IPCOMP=y +CONFIG_INET_XFRM_TUNNEL=y +CONFIG_INET6_IPCOMP=y +CONFIG_INET6_XFRM_TUNNEL=y -- 2.43.0

1 year, 2 months

3
3
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[PATCH 0/2] usercopy: Convert test_user_copy to KUnit test

by Kees Cook

Hi, This builds on the proposal[1] from Mark and lets me convert the existing usercopy selftest to KUnit. Besides adding this basic test to the KUnit collection, it also opens the door for execve testing (which depends on having a functional current->mm), and should provide the basic infrastructure for adding Mark's much more complete usercopy tests. -Kees [1] https://lore.kernel.org/lkml/20230321122514.1743889-2-mark.rutland@arm.com/ Kees Cook (2): kunit: test: Add vm_mmap() allocation resource manager usercopy: Convert test_user_copy to KUnit test MAINTAINERS | 1 + include/kunit/test.h | 17 ++ lib/Kconfig.debug | 21 +- lib/Makefile | 2 +- lib/kunit/test.c | 139 +++++++++++- lib/{test_user_copy.c => usercopy_kunit.c} | 252 ++++++++++----------- 6 files changed, 288 insertions(+), 144 deletions(-) rename lib/{test_user_copy.c => usercopy_kunit.c} (52%) -- 2.34.1

1 year, 2 months

5
10
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[PATCH v6 00/16] selftests/resctrl: resctrl_val() related cleanups & improvements

by Ilpo Järvinen

Hi all, This series does a number of cleanups into resctrl_val() and generalizes it by removing test name specific handling from the function. v6: - Adjust closing/rollback of the IMC perf - Move the comment in measure_vals() to function level - Capitalize MBM - binded to -> bound to - Language tweak into kerneldoc - Removed stale paragraph from commit message v5: - Open mem bw file only once and use rewind(). - Add \n to mem bw file read to allow reading fresh values from the file. - Return 0 if create_grp() is given NULL grp_name (matches the original behavior). Mention this in function's kerneldoc. - Cast pid_t to int before printing with %d. - Caps/typo fixes to kerneldoc and commit messages. - Use imperative tone in commit messages and improve them based on points that came up during review. v4: - Merged close fix into IMC READ+WRITE rework patch - Add loop to reset imc_counters_config fds to -1 to be able know which need closing - Introduce perf_close_imc_mem_bw() to close fds - Open resctrl mem bw file (twice) beforehand to avoid opening it during the test - Remove MBM .mongrp setup - Remove mongrp from CMT test v3: - Rename init functions to <testname>_init() - Replace for loops with READ+WRITE statements for clarity - Don't drop Return: entry from perf_open_imc_mem_bw() func comment - New patch: Fix closing of IMC fds in case of error - New patch: Make "bandwidth" consistent in comments & prints - New patch: Simplify mem bandwidth file code - Remove wrong comment - Changed grp_name check to return -1 on fail (internal sanity check) v2: - Resolved conflicts with kselftest/next - Spaces -> tabs correction Ilpo Järvinen (16): selftests/resctrl: Fix closing IMC fds on error and open-code R+W instead of loops selftests/resctrl: Calculate resctrl FS derived mem bw over sleep(1) only selftests/resctrl: Make "bandwidth" consistent in comments & prints selftests/resctrl: Consolidate get_domain_id() into resctrl_val() selftests/resctrl: Use correct type for pids selftests/resctrl: Cleanup bm_pid and ppid usage & limit scope selftests/resctrl: Rename measure_vals() to measure_mem_bw_vals() & document selftests/resctrl: Simplify mem bandwidth file code for MBA & MBM tests selftests/resctrl: Add ->measure() callback to resctrl_val_param selftests/resctrl: Add ->init() callback into resctrl_val_param selftests/resctrl: Simplify bandwidth report type handling selftests/resctrl: Make some strings passed to resctrlfs functions const selftests/resctrl: Convert ctrlgrp & mongrp to pointers selftests/resctrl: Remove mongrp from MBA test selftests/resctrl: Remove mongrp from CMT test selftests/resctrl: Remove test name comparing from write_bm_pid_to_resctrl() tools/testing/selftests/resctrl/cache.c | 10 +- tools/testing/selftests/resctrl/cat_test.c | 5 +- tools/testing/selftests/resctrl/cmt_test.c | 22 +- tools/testing/selftests/resctrl/mba_test.c | 26 +- tools/testing/selftests/resctrl/mbm_test.c | 26 +- tools/testing/selftests/resctrl/resctrl.h | 49 ++- tools/testing/selftests/resctrl/resctrl_val.c | 371 ++++++++---------- tools/testing/selftests/resctrl/resctrlfs.c | 67 ++-- 8 files changed, 291 insertions(+), 285 deletions(-) -- 2.39.2

1 year, 2 months

2
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Linux-kselftest-mirror June 2024