From 9cc63f8bcd560c760d0b12e15bba8f81c86237cf Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Fri, 14 Aug 2026 15:43:51 -0700 Subject: Merge branches 'expcb.2026.07.24a', 'misc.2026.07.30a', 'rcu-tasks.2026.07.30a', 'srcu.2026.08.11a' and 'torture.2026.08.14a' into HEAD Changes: Make expedited grace periods expedite normal RCU callbacks Miscellaneous fixes: * Improve diagnostic output with character task states. * Mark accesses to inform KCSAN of concurrency design. * Move from kmalloc() to kmalloc_obj(). * Documentation updates. * Improve handling of RCU deferred quiescent states. * Clean up unused function arguments and structure fields. * Reduce show_rcu_gp_kthreads() stack space. Tasks RCU updates: * Clean up after SRCU re-implementation of Tasks Trace RCU. * Mark accesses to inform KCSAN of concurrency design. * Add ->lazy_timer status to diagnostic output. * Remove an unnecessary memory barrier. * Fix a data race, courtesy of KCSAN. * Documentation updates. * Convert cond_resched_tasks_rcu_qs() from macro to static inline function. SRCU updates: * Add Rust helpers for SRCU. * Avoid losing queued work at cleanup_srcu_struct() time. Torture-test updates: * Preparation work for immediate RCU priority deboosting. * Test RCU readers from real interrupt handlers (as opposed to softirq). * Simplify code through use of cpumask_next_wrap(). * Improve diagnostic output with character task states. * Add rcutorture.nwriters parameter to allow lightweight stall testing, and rcutorture.stall_only to make doing so easier. * Test an RCU Tasks Trace grace period implying an RCU grace period. * Make RCU Tasks Trace torturing track reader batches. * Fix a data race, courtesy of KCSAN. * Plug a shuffle_tmp_mask memory leak on kthread spawn failure. --- tools/perf/util/target.c | 142 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 142 insertions(+) create mode 100644 tools/perf/util/target.c (limited to 'tools/perf/util/target.c') diff --git a/tools/perf/util/target.c b/tools/perf/util/target.c new file mode 100644 index 000000000..8cf71bea2 --- /dev/null +++ b/tools/perf/util/target.c @@ -0,0 +1,142 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Helper functions for handling target threads/cpus + * + * Copyright (C) 2012, LG Electronics, Namhyung Kim + */ + +#include "target.h" + +#include +#include +#include +#include +#include +#include + +enum target_errno target__validate(struct target *target) +{ + enum target_errno ret = TARGET_ERRNO__SUCCESS; + + if (target->pid) + target->tid = target->pid; + + /* CPU and PID are mutually exclusive */ + if (target->tid && target->cpu_list) { + target->cpu_list = NULL; + if (ret == TARGET_ERRNO__SUCCESS) + ret = TARGET_ERRNO__PID_OVERRIDE_CPU; + } + + /* PID and SYSTEM are mutually exclusive */ + if (target->tid && target->system_wide) { + target->system_wide = false; + if (ret == TARGET_ERRNO__SUCCESS) + ret = TARGET_ERRNO__PID_OVERRIDE_SYSTEM; + } + + /* BPF and CPU are mutually exclusive */ + if (target->bpf_str && target->cpu_list) { + target->cpu_list = NULL; + if (ret == TARGET_ERRNO__SUCCESS) + ret = TARGET_ERRNO__BPF_OVERRIDE_CPU; + } + + /* BPF and PID/TID are mutually exclusive */ + if (target->bpf_str && target->tid) { + target->tid = NULL; + if (ret == TARGET_ERRNO__SUCCESS) + ret = TARGET_ERRNO__BPF_OVERRIDE_PID; + } + + /* BPF and THREADS are mutually exclusive */ + if (target->bpf_str && target->per_thread) { + target->per_thread = false; + if (ret == TARGET_ERRNO__SUCCESS) + ret = TARGET_ERRNO__BPF_OVERRIDE_THREAD; + } + + /* THREAD and SYSTEM/CPU are mutually exclusive */ + if (target->per_thread && (target->system_wide || target->cpu_list)) { + target->per_thread = false; + if (ret == TARGET_ERRNO__SUCCESS) + ret = TARGET_ERRNO__SYSTEM_OVERRIDE_THREAD; + } + + return ret; +} + +uid_t parse_uid(const char *str) +{ + struct passwd pwd, *result; + char buf[1024]; + + if (str == NULL) + return UINT_MAX; + + /* Try user name first */ + getpwnam_r(str, &pwd, buf, sizeof(buf), &result); + + if (result == NULL) { + /* + * The user name not found. Maybe it's a UID number. + */ + char *endptr; + int uid = strtol(str, &endptr, 10); + + if (*endptr != '\0') + return UINT_MAX; + + getpwuid_r(uid, &pwd, buf, sizeof(buf), &result); + + if (result == NULL) + return UINT_MAX; + } + + return result->pw_uid; +} + +/* + * This must have a same ordering as the enum target_errno. + */ +static const char *target__error_str[] = { + "PID/TID switch overriding CPU", + "PID/TID switch overriding SYSTEM", + "SYSTEM/CPU switch overriding PER-THREAD", + "BPF switch overriding CPU", + "BPF switch overriding PID/TID", + "BPF switch overriding THREAD", +}; + +int target__strerror(struct target *target __maybe_unused, int errnum, + char *buf, size_t buflen) +{ + int idx; + const char *msg; + + BUG_ON(buflen == 0); + + if (errnum >= 0) { + str_error_r(errnum, buf, buflen); + return 0; + } + + if (errnum < __TARGET_ERRNO__START || errnum >= __TARGET_ERRNO__END) + return -1; + + idx = errnum - __TARGET_ERRNO__START; + msg = target__error_str[idx]; + + switch (errnum) { + case TARGET_ERRNO__PID_OVERRIDE_CPU ... + TARGET_ERRNO__BPF_OVERRIDE_THREAD: + snprintf(buf, buflen, "%s", msg); + break; + + default: + /* cannot reach here */ + break; + } + + return 0; +} -- cgit v1.3.1