Hi Al, On Thu, 24 Sep 2020 21:08:07 +0100 Al Viro wrote: > > On Thu, Sep 24, 2020 at 06:30:38PM +1000, Stephen Rothwell wrote: > > > > After merging the vfs tree, today's linux-next build (x86_64 allnoconfig) > > failed like this: > > > > arch/x86/include/asm/barrier.h: Assembler messages: > > arch/x86/include/asm/barrier.h:41: Error: operand type mismatch for `cmp' > > arch/x86/include/asm/barrier.h:41: Error: operand type mismatch for `cmp' > > > > and many more ... > > > > Caused by commit > > > > e33ea6e5ba6a ("x86/uaccess: Use pointer masking to limit uaccess speculation") > > > > I am not exactly sure why (but reverting it fixes the build). > > > > I have reverted that commit for today. > > Can't reproduce here... This on top of today's -next seems to build with > allnoconfig here: I don't know what to tell you ... it still fails for me today. $ x86_64-linux-gnu-gcc --version x86_64-linux-gnu-gcc (Debian 10.2.0-9) 10.2.0 $ x86_64-linux-gnu-ld --version GNU ld (GNU Binutils for Debian) 2.35 and the gcc plugins don't get built for the allnoconfig builds. > diff --git a/lib/iov_iter.c b/lib/iov_iter.c > index 35293ad83297..aca828b9b831 100644 > --- a/lib/iov_iter.c > +++ b/lib/iov_iter.c > @@ -647,7 +647,7 @@ static int copyout_mc(void __user *to, const void *from, size_t n) > { > if (access_ok(to, n)) { > instrument_copy_to_user(to, from, n); > - n = copy_mc_to_user((__force void *) to, from, n); > + n = copy_mc_to_user((__force void *)force_user_ptr(to), from, n); BTW, You can't do that because force_user_ptr is only defined for x86 ... I reverted my Revert commit after I finished linux-next today and built the x86_64 allnoconfig verion of lib/iov_iter.s: $ grep -A 1 '41 "/home/sfr/next/next/arch/x86/include/asm/barrier.h"' lib/iov_iter.s # 41 "/home/sfr/next/next/arch/x86/include/asm/barrier.h" 1 cmp $140737488351232,%rdx; sbb %rcx,%rcx; #, uaddr, mask -- # 41 "/home/sfr/next/next/arch/x86/include/asm/barrier.h" 1 cmp $140737488351232,%r8; sbb %rdx,%rdx; #, end, mask -- # 41 "/home/sfr/next/next/arch/x86/include/asm/barrier.h" 1 cmp $140737488351232,%rdx; sbb %rcx,%rcx; #, uaddr, mask -- # 41 "/home/sfr/next/next/arch/x86/include/asm/barrier.h" 1 cmp $140737488351232,%rdi; sbb %rdx,%rdx; #, end, mask -- # 41 "/home/sfr/next/next/arch/x86/include/asm/barrier.h" 1 cmp $140737488351232,%rdi; sbb %rax,%rax; #, to.29_334, mask -- # 41 "/home/sfr/next/next/arch/x86/include/asm/barrier.h" 1 cmp $140737488351232,%rdi; sbb %rax,%rax; #, to.29_367, mask -- # 41 "/home/sfr/next/next/arch/x86/include/asm/barrier.h" 1 cmp $140737488351232,%rsi; sbb %rax,%rax; #, from.37_239, mask -- # 41 "/home/sfr/next/next/arch/x86/include/asm/barrier.h" 1 cmp $140737488351232,%rsi; sbb %rax,%rax; #, from.37_272, mask -- # 41 "/home/sfr/next/next/arch/x86/include/asm/barrier.h" 1 cmp $140737488351232,%rsi; sbb %rax,%rax; #, _i, mask -- # 41 "/home/sfr/next/next/arch/x86/include/asm/barrier.h" 1 cmp $140737488351232,%rsi; sbb %rax,%rax; #, _i, mask -- # 41 "/home/sfr/next/next/arch/x86/include/asm/barrier.h" 1 cmp $140737488351232,%rsi; sbb %rax,%rax; #, _i, mask -- # 41 "/home/sfr/next/next/arch/x86/include/asm/barrier.h" 1 cmp $140737488351232,%rsi; sbb %rax,%rax; #, _i, mask -- # 41 "/home/sfr/next/next/arch/x86/include/asm/barrier.h" 1 cmp $140737488351232,%rdi; sbb %rax,%rax; #, to.29_96, mask -- # 41 "/home/sfr/next/next/arch/x86/include/asm/barrier.h" 1 cmp $140737488351232,%rdi; sbb %rax,%rax; #, to.29_244, mask -- # 41 "/home/sfr/next/next/arch/x86/include/asm/barrier.h" 1 cmp $140737488351232,%rsi; sbb %rax,%rax; #, from.37_68, mask -- # 41 "/home/sfr/next/next/arch/x86/include/asm/barrier.h" 1 cmp $140737488351232,%rsi; sbb %rax,%rax; #, from.37_221, mask -- # 41 "/home/sfr/next/next/arch/x86/include/asm/barrier.h" 1 cmp $140737488351232,%rsi; sbb %r10,%r10; #, from.37_281, mask -- # 41 "/home/sfr/next/next/arch/x86/include/asm/barrier.h" 1 cmp $140737488351232,%rsi; sbb %rax,%rax; #, from.37_314, mask -- # 41 "/home/sfr/next/next/arch/x86/include/asm/barrier.h" 1 cmp $140737488351232,%rsi; sbb %r10,%r10; #, from.37_177, mask -- # 41 "/home/sfr/next/next/arch/x86/include/asm/barrier.h" 1 cmp $140737488351232,%rsi; sbb %rax,%rax; #, from.37_210, mask -- # 41 "/home/sfr/next/next/arch/x86/include/asm/barrier.h" 1 cmp $140737488351232,%r10; sbb %rsi,%rsi; #, _i, mask -- # 41 "/home/sfr/next/next/arch/x86/include/asm/barrier.h" 1 cmp $140737488351232,%rsi; sbb %rax,%rax; #, _i, mask I don't know if that helps. -- Cheers, Stephen Rothwell