On Fri, Aug 01, 2025 at 06:47:46AM +0200, Jiri Slaby wrote: > On 31. 07. 25, 22:58, Nicolas Pitre wrote: > > On Thu, 31 Jul 2025, Christophe Leroy wrote: > > > > > > > > > > > Le 31/07/2025 à 16:35, Christophe Leroy a écrit : > > > > Hi Jiri, > > > > > > > > Le 11/06/2025 à 12:02, Jiri Slaby (SUSE) a écrit : > > > > > _IO*() is the proper way of defining ioctl numbers. All these vt > > > > > numbers > > > > > were synthetically built up the same way the _IO() macro does. > > > > > > > > > > So instead of implicit hex numbers, use _IO() properly. > > > > > > > > > > To not change the pre-existing numbers, use only _IO() (and not _IOR() > > > > > or _IOW()). The latter would change the numbers indeed. > > > > > > > > On powerpc your assumption is wrong, because _IOC_NONE is not 0: > > > > > > > > $ git grep _IOC_NONE arch/powerpc/ > > > > arch/powerpc/include/uapi/asm/ioctl.h:#define _IOC_NONE 1U > > > > > > > > Therefore the value changes even with _IO(), leading to failure of Xorg > > > > as > > > > reported by Christian. > > > > > > > > > > And is likely an issue on the 4 following architectures: > > > > > > $ git grep _IOC_NONE arch/ | grep 1U > > > arch/alpha/include/uapi/asm/ioctl.h:#define _IOC_NONE 1U > > > arch/mips/include/uapi/asm/ioctl.h:#define _IOC_NONE 1U > > > arch/powerpc/include/uapi/asm/ioctl.h:#define _IOC_NONE 1U > > > arch/sparc/include/uapi/asm/ioctl.h:#define _IOC_NONE 1U > > > > IMHO this one patch could simply be reverted and the "old" code let be. > > Oh, right -- it's easy to revert (no conflicts). > > We could use _IOC(0, 'V', number, 0) directly, but I am not sure, that's > worth it.
Great, can someone send me a revert? thanks, greg k-h
