Messages in this thread | | | Date | Tue, 30 Jun 2020 11:33:24 -0500 | From | Segher Boessenkool <> | Subject | Re: [PATCH v2] powerpc/uaccess: Use flexible addressing with __put_user()/__get_user() |
| |
On Tue, Jun 30, 2020 at 04:55:05PM +0200, Christophe Leroy wrote: > Le 30/06/2020 à 03:19, Michael Ellerman a écrit : > >Michael Ellerman <mpe@ellerman.id.au> writes: > >>Because it uses the "m<>" constraint which didn't work on GCC 4.6. > >> > >>https://github.com/linuxppc/issues/issues/297 > >> > >>So we should be able to pick it up for v5.9 hopefully. > > > >It seems to break the build with the kernel.org 4.9.4 compiler and > >corenet64_smp_defconfig: > > Looks like 4.9.4 doesn't accept "m<>" constraint either.
The evidence contradicts this assertion.
> Changing it to "m" make it build.
But that just means something else is wrong.
> >+ make -s CC=powerpc64-linux-gnu-gcc -j 160 > >In file included from /linux/include/linux/uaccess.h:11:0, > > from /linux/include/linux/sched/task.h:11, > > from /linux/include/linux/sched/signal.h:9, > > from /linux/include/linux/rcuwait.h:6, > > from /linux/include/linux/percpu-rwsem.h:7, > > from /linux/include/linux/fs.h:33, > > from /linux/include/linux/huge_mm.h:8, > > from /linux/include/linux/mm.h:675, > > from /linux/arch/powerpc/kernel/signal_32.c:17: > >/linux/arch/powerpc/kernel/signal_32.c: In function > >'save_user_regs.isra.14.constprop': > >/linux/arch/powerpc/include/asm/uaccess.h:161:2: error: 'asm' operand has > >impossible constraints > > __asm__ __volatile__( \ > > ^ > >/linux/arch/powerpc/include/asm/uaccess.h:197:12: note: in expansion of > >macro '__put_user_asm' > > case 4: __put_user_asm(x, ptr, retval, "stw"); break; \ > > ^ > >/linux/arch/powerpc/include/asm/uaccess.h:206:2: note: in expansion of > >macro '__put_user_size_allowed' > > __put_user_size_allowed(x, ptr, size, retval); \ > > ^ > >/linux/arch/powerpc/include/asm/uaccess.h:220:2: note: in expansion of > >macro '__put_user_size' > > __put_user_size(__pu_val, __pu_addr, __pu_size, __pu_err); \ > > ^ > >/linux/arch/powerpc/include/asm/uaccess.h:96:2: note: in expansion of > >macro '__put_user_nocheck' > > __put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr))) > > ^ > >/linux/arch/powerpc/kernel/signal_32.c:120:7: note: in expansion of macro > >'__put_user' > > if (__put_user((unsigned int)gregs[i], &frame->mc_gregs[i])) > > ^
Can we see what that was after the macro jungle? Like, the actual preprocessed code?
Also, what GCC version *does* work on this?
Segher
| |