On Thu, Aug 11, 2011 at 1:50 PM, Jeff Haran <jharan@bytemobile.com> wrote:
-----Original Message----- From: kernelnewbies-bounces@kernelnewbies.org [mailto:kernelnewbies- bounces@kernelnewbies.org] On Behalf Of william douglas Sent: Thursday, August 11, 2011 1:23 PM To: kernelnewbies@kernelnewbies.org Subject: SYSLOG_ACTION_READ_ALL question
Hello all,
I'm trying to figure out why the do_syslog code in kernel/printk.c is using put_user instead of copy_to_user.
I *THINK* this has something to do with copy_to_user not being well-behaved in other than process context and since printk() gets called in all contexts, it wouldn't be a safe operation. But don't take my word for it.
Well from what I understand, copy_to_user doesn't work in interrupt context for example as there is no user space necessarily to copy to. In this case we have a __user buffer to copy back to and __copy_to_user looks sane for the work load so I'm still unsure.