Hi again, Thanks for your work so far!
On Tue, Jun 30, 2020 at 06:53:39PM +0000, Christophe Leroy wrote: > On 06/30/2020 04:33 PM, Segher Boessenkool wrote: > >>>+ 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? > > Sorry for previous misunderstanding > > Here is the code: > > #define __put_user_asm(x, addr, err, op) \ > __asm__ __volatile__( \ > "1: " op "%U2%X2 %1,%2 # put_user\n" \ > "2:\n" \ > ".section .fixup,\"ax\"\n" \ > "3: li %0,%3\n" \ > " b 2b\n" \ > ".previous\n" \ > EX_TABLE(1b, 3b) \ > : "=r" (err) \ > : "r" (x), "m<>" (*addr), "i" (-EFAULT), "0" (err)) Yeah I don't see it. I'll have to look at compiler debug dumps, but I don't have any working 4.9 around, and I cannot reproduce this with either older or newer compilers. It is complainig that constrain_operands just does not work *at all* on this "m<>" constraint apparently, which doesn't make much sense. I'll try later when I have more time, sorry :-/ Segher