Messages in this thread | | | Date | Tue, 3 Oct 2017 16:53:08 +0200 | From | Peter Zijlstra <> | Subject | Re: [RFC PATCH 15/17] perf: Allow controlled non-root access to detached events |
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On Tue, Sep 05, 2017 at 04:30:24PM +0300, Alexander Shishkin wrote: > @@ -5587,7 +5587,13 @@ static int perf_open(struct inode *inode, struct file *file) > if (!atomic_long_inc_not_zero(&event->refcount)) > return -ENOENT; > > - ret = simple_open(inode, file); > + /* event's user is stable while we're holding the reference */ > + if (event->rb->mmap_user != current_user() && > + !capable(CAP_SYS_ADMIN)) > + ret = -EACCES; > + > + if (!ret) > + ret = simple_open(inode, file); > if (ret) > put_event(event); >
> @@ -11530,6 +11537,18 @@ static int perf_instance_unlink(const char *name) > if (!event) > return -EINVAL; > > + if (!atomic_long_inc_not_zero(&event->refcount)) > + return 0; > + > + /* event's user is stable while we're holding the reference */ > + if (event->rb->mmap_user != current_user() && > + !capable(CAP_SYS_ADMIN)) > + ret = -EACCES; > + put_event(event); > + > + if (ret) > + return ret; > + > if (!(event->attach_state & PERF_ATTACH_CONTEXT)) > return -EBUSY; >
Why aren't we using regular file permissions for this?
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