https://github.com/torvalds/linux
Tip revision: 22a40d14b572deb80c0648557f4bd502d7e83826 authored by Linus Torvalds on 30 June 2024, 21:40:44 UTC
Linux 6.10-rc6
Linux 6.10-rc6
Tip revision: 22a40d1
target.c
// SPDX-License-Identifier: GPL-2.0-only
/*
* Helper functions for handling target threads/cpus
*
* Copyright (C) 2012, LG Electronics, Namhyung Kim <namhyung.kim@lge.com>
*/
#include "target.h"
#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <linux/kernel.h>
#include <linux/string.h>
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;
}
/* UID and PID are mutually exclusive */
if (target->tid && target->uid_str) {
target->uid_str = NULL;
if (ret == TARGET_ERRNO__SUCCESS)
ret = TARGET_ERRNO__PID_OVERRIDE_UID;
}
/* UID and CPU are mutually exclusive */
if (target->uid_str && target->cpu_list) {
target->cpu_list = NULL;
if (ret == TARGET_ERRNO__SUCCESS)
ret = TARGET_ERRNO__UID_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;
}
/* UID and SYSTEM are mutually exclusive */
if (target->uid_str && target->system_wide) {
target->system_wide = false;
if (ret == TARGET_ERRNO__SUCCESS)
ret = TARGET_ERRNO__UID_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 UID are mutually exclusive */
if (target->bpf_str && target->uid_str) {
target->uid_str = NULL;
if (ret == TARGET_ERRNO__SUCCESS)
ret = TARGET_ERRNO__BPF_OVERRIDE_UID;
}
/* 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;
}
enum target_errno target__parse_uid(struct target *target)
{
struct passwd pwd, *result;
char buf[1024];
const char *str = target->uid_str;
target->uid = UINT_MAX;
if (str == NULL)
return TARGET_ERRNO__SUCCESS;
/* 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 TARGET_ERRNO__INVALID_UID;
getpwuid_r(uid, &pwd, buf, sizeof(buf), &result);
if (result == NULL)
return TARGET_ERRNO__USER_NOT_FOUND;
}
target->uid = result->pw_uid;
return TARGET_ERRNO__SUCCESS;
}
/*
* 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 UID",
"UID switch overriding CPU",
"PID/TID switch overriding SYSTEM",
"UID switch overriding SYSTEM",
"SYSTEM/CPU switch overriding PER-THREAD",
"BPF switch overriding CPU",
"BPF switch overriding PID/TID",
"BPF switch overriding UID",
"BPF switch overriding THREAD",
"Invalid User: %s",
"Problems obtaining information for user %s",
};
int target__strerror(struct target *target, 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;
case TARGET_ERRNO__INVALID_UID:
case TARGET_ERRNO__USER_NOT_FOUND:
snprintf(buf, buflen, msg, target->uid_str);
break;
default:
/* cannot reach here */
break;
}
return 0;
}