On 04/15/2014 08:28 PM, Vince Weaver wrote: > > Attempt to clarify the reasons for EACCES and EPERM errors. Thanks, Vince. Applied. Cheers, Michael > Signed-off-by: Vince Weaver <vincent.weaver@xxxxxxxxx> > > diff --git a/man2/perf_event_open.2 b/man2/perf_event_open.2 > index e513905..00842df 100644 > --- a/man2/perf_event_open.2 > +++ b/man2/perf_event_open.2 > @@ -2385,11 +2385,14 @@ field is overwritten by the kernel to be the size of the structure > it was expecting. > .TP > .B EACCES > -Returned when the requested event requires root permissions > -(or a more permissive perf_event paranoid setting). > -Some common cases where an unprivileged process > -may encounter this error: are attaching to a process owned by a different user; > -monitoring all processes on a given CPU; > +Returned when the requested event requires > +.B 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 (including those not belonging to the user) > +on a given CPU; > and not setting > .I exclude_kernel > when the paranoid setting requires it. > @@ -2477,9 +2480,17 @@ branch tracing if it is not available, sampling if no PMU > interrupt is available, and branch stacks for software events. > .TP > .B EPERM > -Returned if sufficient permissions not available to create the event. > -This includes attempting to set a breakpoint on a kernel address > -and setting a ftrace function trace tracepoint. > +Returned on many (but not all) architectures when an unsupported > +.IR exclude_hv ", " exclude_idle ", " exclude_user ", or " exclude_kernel > +setting is specified. > + > +It can also happen, as with > +.BR EACCES , > +when the requested event requires > +.B 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. > .TP > .B ESRCH > Returned if attempting to attach to a process that does not exist. > -- Michael Kerrisk Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ Linux/UNIX System Programming Training: http://man7.org/training/ -- To unsubscribe from this list: send the line "unsubscribe linux-man" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
