Messages in this thread | | | Date | Wed, 18 Nov 2020 12:47:02 +0100 | From | Petr Mladek <> | Subject | Re: [PATCH] reboot: Fix variable assignments in type_store |
| |
On Fri 2020-11-13 22:28:18, Matteo Croce wrote: > On Fri, Nov 13, 2020 at 9:06 PM Petr Mladek <pmladek@suse.com> wrote: > > > > On Fri 2020-11-13 03:58:49, Matteo Croce wrote: > > > On Fri, Nov 13, 2020 at 3:46 AM Andrew Morton <akpm@linux-foundation.org> wrote: > > > > > > > > On Fri, 13 Nov 2020 02:38:18 +0100 Matteo Croce <mcroce@linux.microsoft.com> wrote: > > > > > > > > > At this point, since 'pci' enables BOOT_CF9_FORCE type and > > > > > BOOT_CF9_SAFE is not user selectable, should I simply leave only > > > > > 'pci'? > > > > > > > > > > This way, we'll have the same set of options for both sysfs and kernel cmdline. > > > > > > > > Well, you're the reboot expert ;) > > > > > > > > > > So honored! :) > > > > > > > But my $0.02 is yes, let's keep the command-line and sysfs interfaces > > > > in sync and cover it all in documentation. It would of course be > > > > problematic to change the existing reboot= interface. > > > > > > > > I assume that means doing this? > > > > > > > > - #define BOOT_CF9_FORCE_STR "cf9_force" > > > > + #define BOOT_CF9_FORCE_STR "pci" > > > > - #define BOOT_CF9_SAFE_STR "cf9_safe" > > > > > > Either BOOT_PCI_STR or BOOT_CF9_FORCE_STR, I have no strong preference. > > > > > > The syntax is 'pci' while the enum BOOT_CF9_FORCE, so we can't please both. > > > > The question is whether we should modify/allow to set these values at > > all. > > > > Anyway, we must prevent them on non-x86 architectures because > > the reboot behavior would be undefined there. They could probably > > make a mess even on many x86-architectures. > > > > That's right, but the same can be obtained by passing 'reboot=pci' on > non x86 machines: the cmdline parsing is generic and will set > reboot_type on all arches.
Fair enough. Ah, I mixed reboot_type and reboot_mode and looked into wrong part of reboot_setup().
> I looked at the reboot_type usage, there isn't any reference outside > arch/x86. In fact, the parameter is just ignored: > > # uname -m > aarch64 > # cat /proc/cmdline > console=ttyS0,115200n8 reboot=pci > # reboot -ff > Rebooting. > [ 43.893833] reboot: Restarting system
Good to know. Thanks for checking.
> The same applies for reboot_force, the only flags available on > different architectures are reboot_mode and reboot_cpu. > We could hide some handlers for some architectures. We save some > space, and avoid letting the user set flags which do nothing.
I am fine with the current patchset after all. We could always make it more safe when people hit it in the real life. All these worries were because I thought that this interface allowed to set values that were not possible before.
> > Anyway, we should get input from some x86-experts about the BOOT_CF9 > > values. > > Sure, x86@kernel.org ?
Yes but I do not resist on it any longer. Just if you were going to send another version just by chance then it would be nice to CC x86.
Best Regards, Petr
| |