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b4c658d4d6
Gathering threads with a uid by scanning /proc is inherently racy leading to perf_event_open failures that quit perf. All users of the functionality now use BPF filters, so remove uid and uid_str from target. Signed-off-by: Ian Rogers <irogers@google.com> Link: https://lore.kernel.org/r/20250604174545.2853620-10-irogers@google.com Signed-off-by: Namhyung Kim <namhyung@kernel.org>
142 lines
3.1 KiB
C
142 lines
3.1 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Helper functions for handling target threads/cpus
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*
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* Copyright (C) 2012, LG Electronics, Namhyung Kim <namhyung.kim@lge.com>
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*/
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#include "target.h"
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#include <pwd.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <linux/kernel.h>
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#include <linux/string.h>
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enum target_errno target__validate(struct target *target)
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{
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enum target_errno ret = TARGET_ERRNO__SUCCESS;
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if (target->pid)
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target->tid = target->pid;
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/* CPU and PID are mutually exclusive */
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if (target->tid && target->cpu_list) {
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target->cpu_list = NULL;
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if (ret == TARGET_ERRNO__SUCCESS)
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ret = TARGET_ERRNO__PID_OVERRIDE_CPU;
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}
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/* PID and SYSTEM are mutually exclusive */
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if (target->tid && target->system_wide) {
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target->system_wide = false;
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if (ret == TARGET_ERRNO__SUCCESS)
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ret = TARGET_ERRNO__PID_OVERRIDE_SYSTEM;
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}
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/* BPF and CPU are mutually exclusive */
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if (target->bpf_str && target->cpu_list) {
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target->cpu_list = NULL;
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if (ret == TARGET_ERRNO__SUCCESS)
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ret = TARGET_ERRNO__BPF_OVERRIDE_CPU;
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}
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/* BPF and PID/TID are mutually exclusive */
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if (target->bpf_str && target->tid) {
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target->tid = NULL;
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if (ret == TARGET_ERRNO__SUCCESS)
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ret = TARGET_ERRNO__BPF_OVERRIDE_PID;
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}
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/* BPF and THREADS are mutually exclusive */
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if (target->bpf_str && target->per_thread) {
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target->per_thread = false;
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if (ret == TARGET_ERRNO__SUCCESS)
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ret = TARGET_ERRNO__BPF_OVERRIDE_THREAD;
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}
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/* THREAD and SYSTEM/CPU are mutually exclusive */
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if (target->per_thread && (target->system_wide || target->cpu_list)) {
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target->per_thread = false;
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if (ret == TARGET_ERRNO__SUCCESS)
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ret = TARGET_ERRNO__SYSTEM_OVERRIDE_THREAD;
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}
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return ret;
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}
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uid_t parse_uid(const char *str)
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{
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struct passwd pwd, *result;
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char buf[1024];
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if (str == NULL)
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return UINT_MAX;
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/* Try user name first */
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getpwnam_r(str, &pwd, buf, sizeof(buf), &result);
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if (result == NULL) {
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/*
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* The user name not found. Maybe it's a UID number.
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*/
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char *endptr;
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int uid = strtol(str, &endptr, 10);
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if (*endptr != '\0')
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return UINT_MAX;
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getpwuid_r(uid, &pwd, buf, sizeof(buf), &result);
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if (result == NULL)
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return UINT_MAX;
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}
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return result->pw_uid;
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}
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/*
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* This must have a same ordering as the enum target_errno.
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*/
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static const char *target__error_str[] = {
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"PID/TID switch overriding CPU",
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"PID/TID switch overriding SYSTEM",
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"SYSTEM/CPU switch overriding PER-THREAD",
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"BPF switch overriding CPU",
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"BPF switch overriding PID/TID",
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"BPF switch overriding THREAD",
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};
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int target__strerror(struct target *target __maybe_unused, int errnum,
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char *buf, size_t buflen)
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{
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int idx;
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const char *msg;
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BUG_ON(buflen == 0);
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if (errnum >= 0) {
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str_error_r(errnum, buf, buflen);
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return 0;
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}
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if (errnum < __TARGET_ERRNO__START || errnum >= __TARGET_ERRNO__END)
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return -1;
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idx = errnum - __TARGET_ERRNO__START;
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msg = target__error_str[idx];
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switch (errnum) {
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case TARGET_ERRNO__PID_OVERRIDE_CPU ...
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TARGET_ERRNO__BPF_OVERRIDE_THREAD:
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snprintf(buf, buflen, "%s", msg);
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break;
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default:
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/* cannot reach here */
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break;
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}
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return 0;
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}
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