On 2021/02/11 1:54, Andy Shevchenko wrote: > On Thu, Feb 11, 2021 at 01:39:41AM +0900, Tetsuo Handa wrote: >> On 2021/02/11 1:18, Steven Rostedt wrote: >>> The point of this exercise is to be able to debug the *same* kernel that >>> someone is having issues with. And this is to facilitate that debugging. >> >> That's too difficult to use. If a problem is not reproducible, we will have >> no choice but always specify "never hash pointers" command line option. If a >> problem is reproducible, we can rebuild that kernel with "never hash pointers" >> config option turned on. > > I think what you are targeting is something like dynamic debug approach where > you can choose which prints to enable/disable and what enable/disable in them. What I'm targeting is "zero interaction from kernel command line options" like https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/drivers/usb/usbip?id=f1bdf414e7dd0cbc26460425719fc3ea479947a2 . > > In that case you specifically apply a command line option and enable only files > / lines in the files. While there is boot-config feature for specifying very long kernel command line options, I can't enforce syzkaller users (including syzbot) to switch what to enable/disable via kernel command line options. Let alone defining a kernel command line option for single-purpose debug printk() changes like shown above.
