我能找到的有关该主题的唯一信息是此链接:perf_event_open always returns -1 ，根据我的理解，建议使用 CONFIG_HW_PERF_EVENTS 进行配置，但我仍然遇到同样的问题。
我正在实现一个受 perf_event_open 手册页启发的程序:
static long
perf_event_open(struct perf_event_attr *hw_event, pid_t pid,
int cpu, int group_fd, unsigned long flags)
{
int ret;
ret= syscall(__NR_perf_event_open, hw_event, pid, cpu,
group_fd, flags);
return ret;
}
struct perf_event_attr pe;
int pid = fork();
if (pid > 0 ) {
memset(&pe, 0, sizeof(pe));
pe.type = PERF_TYPE_HARDWARE;
pe.size = sizeof(pe);
pe.config = PERF_COUNT_HW_CPU_CYCLES;
pe.disabled = 0;
pe.exclude_kernel = 0;
pe.exclude_hv = 0;
fd = perf_event_open(&pe, pid, -1, -1, 0);
if (fd == -1) {
perror(0);
exit(EXIT_FAILURE);
}
}
我总是得到 fd 的 -1 返回值，并且 perror 表示权限被拒绝。
当然，我可以使用 sudo 解决该问题，但是还有其他方法可以允许执行 perf_event_open 的权限吗？
PS:我不想更改perf_event_paranoid文件，这使得程序在设置为-1时可以工作；我猜应该是 2 点。
最佳答案
RETURN VALUE section of the Linux perf_event_open() system call部分说明:
... EACCES Returned when the requested event requires CAP_PERFMON (since Linux 5.8) or CAP_SYS_ADMIN permissions (or a more permissive perf_event paranoid setting). Some common cases where an unprivileged process may encounter this error: attaching to a process owned by a different user; monitoring all processes on a given CPU (i.e., specifying the pid argument as -1); and not setting exclude_kernel when the paranoid setting requires it. ... EPERM Returned on many (but not all) architectures when an unsupported exclude_hv, exclude_idle, exclude_user, or exclude_kernel setting is specified. It can also happen, as with EACCES, when the requested event requires CAP_PERFMON (since Linux 5.8) or CAP_SYS_ADMIN permissions (or a more permissive perf_event paranoid setting). This includes setting a breakpoint on a kernel address, and (since Linux 3.13) setting a kernel function-trace tracepoint.
从发布的示例代码中，考虑到您关于偏执设置的声明，值 pe.exclude_kernel = 0; 或 pe.exclude_hv = 0; 可能会导致权限问题.
关于c - perf_event_open 的权限被拒绝，除了使用 sudo 或更改 perf_event_paranoid 文件之外，还有其他方法吗？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/66146189/