Re: [PATCH 2/3] printk: Add %ptc to safely print a task's comm

Andi Kleen
2011-05-11T17:37:16Z

John Stultz <john.stultz@linaro.org> writes:

> Acessing task->comm requires proper locking. However in the past
> access to current->comm could be done without locking. This
> is no longer the case, so all comm access needs to be done
> while holding the comm_lock.
>
> In my attempt to clean up unprotected comm access, I've noticed
> most comm access is done for printk output. To simpify correct
> locking in these cases, I've introduced a new %ptc format,
> which will safely print the corresponding task's comm.
>
> Example use:
> printk("%ptc: unaligned epc - sending SIGBUS.\n", current);

Neat. But you probably want a checkpatch rule for this too
to catch new offenders.

-Andi

--
ak@linux.intel.com -- Speaking for myself only