Messages in this thread | | | Date | Fri, 24 Jan 2014 17:17:55 +0000 | From | Will Deacon <> | Subject | Re: [PATCH V2 4/6] ARM: Make PID_IN_CONTEXTIDR incompatible with PID_NS |
| |
On Fri, Jan 24, 2014 at 05:16:28PM +0000, Adrien Vergé wrote: > 2014/1/24 Will Deacon <will.deacon@arm.com>: > > Are you sure about this? The value we write is actually task_pid_nr, which I > > believe to be globally unique. > > You are right: the task_pid_nr is unique in the system. However when > using namespaces, the so called "PID" is the virtual number that > processes in different namespaces can share. > > This PID is the one visible by user-space tasks, in particular > user-space tracers and debuggers. These programs would expect to find > the PID of the traced process in the Context ID reg, while it is not. > I think it is better to remove confusion by making PID_IN_CONTEXTIDR > and PID_NS incompatible. > > What do you think?
I think I'd rather have the global ID than disable a potentially useful feature, especially since this is likely to be consumed by external trace tools as opposed to user-space tasks.
Will -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |