(+ Arnd) Full patch here: http://marc.info/?l=linux-pci&m=149400953408528 On 6 May 2017 at 10:07, Lukas Wunner <lukas@xxxxxxxxx> wrote: > On Sat, May 06, 2017 at 08:46:07AM +0100, Ard Biesheuvel wrote: >> On 5 May 2017 at 19:38, Lukas Wunner <lukas@xxxxxxxxx> wrote: >> > The CPER parser assumes that the class code is big endian, but at least >> > on this edk2-derived Intel Purley platform it's little endian: > [snip] >> > --- a/include/linux/cper.h >> > +++ b/include/linux/cper.h >> > @@ -416,7 +416,7 @@ struct cper_sec_pcie { >> > struct { >> > __u16 vendor_id; >> > __u16 device_id; >> > - __u8 class_code[3]; >> > + __u32 class_code:24; >> >> I'd like to avoid this change if we can. Couldn't we simply invert the >> order of p[] above? > > Hm, why would you like to avoid it? Because we shouldn't use bitfields in structs in code that should be portable across archs with different endiannesses. > The class_code element isn't > referenced anywhere else in the kernel and this isn't a uapi header, > so the change would only impact out-of-tree drivers. Not sure if > any exist which might be interested in CPER parsing. > The point is that the change in the struct definition is simply not necessary, given that inverting the order of p[] already achieves exactly what we want.
