Messages in this thread | | | Date | Sat, 4 Nov 2023 18:32:57 +0100 | From | Thomas Weißschuh <> | Subject | Re: [PATCH RFC] misc/pvpanic: add support for normal shutdowns |
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On 2023-11-04 18:07:21+0100, Greg Kroah-Hartman wrote: > On Sat, Nov 04, 2023 at 02:56:34PM +0100, Willy Tarreau wrote: > > On Sat, Nov 04, 2023 at 02:53:37PM +0100, Thomas Weißschuh wrote: > > > > > The real reason probably doesn't matter today as the header propably > > > > > can't be dropped from Linux anyways for compatibility reasons. > > > > > > > > > > > And if they need to be here, why not use the proper BIT() macro for it? > > > > > > > > > > This was for uniformity with the existing code. > > > > > I can send a (standalone?) patch to fix it up. > > > > > > > > If we keep it, sure, that would be nice. But let's try to drop it if > > > > possible :) > > > > > > It will break the mentioned scripts/update-linux-headers.sh from qemu. > > > > > > > > > Note: > > > > > > BIT() is part of include/vdso/bits.h which is not part of the > > > uapi. How is it supposed to work? > > > Some other uapi header also use BIT() but that seems to work by accident > > > as the users have the macro defined themselves. > > > > Be careful here, we don't want to expose this kernel macro to userland, > > it would break programs that define their own (possibly different) BIT > > macro. BIT() is used in kernel headers but we should not presume that > > it is available from userland. > > It's already there :( > > I thought we had a uapi-safe version somewhere, but I can't seem to find > it anymore, so I don't remember what it is called.
It seems to be _BITUL() and _BITULL() from include/uapi/linux/const.h.
But first we'd need to figure out if we he can drop the pvpanic.h uapi header. I hoped you could give a definitive answer for that. Personally I'd hate to break stuff for qemu.
Thomas
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