Hi Arnd, On 8/7/22 12:44, Arnd Bergmann wrote: > On Sun, Aug 7, 2022 at 7:28 PM Randy Dunlap <rdunlap@xxxxxxxxxxxxx> wrote: >> >> Don't require 'compat_sys_fadvise64_64' when >> __ARCH_WANT_COMPAT_FADVISE64_64 is not set. >> >> Fixes this build error when CONFIG_ADVISE_SYSCALLS is not set: >> >> include/uapi/asm-generic/unistd.h:649:49: error: 'compat_sys_fadvise64_64' undeclared here (not in a function); did you mean 'ksys_fadvise64_64'? >> 649 | __SC_COMP(__NR3264_fadvise64, sys_fadvise64_64, compat_sys_fadvise64_64) >> arch/riscv/kernel/compat_syscall_table.c:12:42: note: in definition of macro '__SYSCALL' >> 12 | #define __SYSCALL(nr, call) [nr] = (call), >> include/uapi/asm-generic/unistd.h:649:1: note: in expansion of macro '__SC_COMP' >> 649 | __SC_COMP(__NR3264_fadvise64, sys_fadvise64_64, compat_sys_fadvise64_64) >> >> Signed-off-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx> >> Cc: Paul Walmsley <paul.walmsley@xxxxxxxxxx> >> Cc: Palmer Dabbelt <palmer@xxxxxxxxxxx> >> Cc: Albert Ou <aou@xxxxxxxxxxxxxxxxx> >> Cc: linux-riscv@xxxxxxxxxxxxxxxxxxx >> Cc: Arnd Bergmann <arnd@xxxxxxxx> >> Cc: linux-arch@xxxxxxxxxxxxxxx >> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> >> Cc: linux-mm@xxxxxxxxx >> --- >> include/uapi/asm-generic/unistd.h | 2 ++ >> 1 file changed, 2 insertions(+) >> >> --- a/include/uapi/asm-generic/unistd.h >> +++ b/include/uapi/asm-generic/unistd.h >> @@ -645,8 +645,10 @@ __SC_COMP(__NR_execve, sys_execve, compa >> #define __NR3264_mmap 222 >> __SC_3264(__NR3264_mmap, sys_mmap2, sys_mmap) >> /* mm/fadvise.c */ >> +#ifdef __ARCH_WANT_COMPAT_FADVISE64_64 >> #define __NR3264_fadvise64 223 >> __SC_COMP(__NR3264_fadvise64, sys_fadvise64_64, compat_sys_fadvise64_64) >> +#endif >> > > This does not work: __ARCH_WANT_COMPAT_FADVISE64_64 is defined in > arch/riscv/include/asm/unistd.h, which is not a UAPI header. By making the line > conditional on this, user space no longer sees the macro definition. > > It looks like you also drop the native definition on all architectures other > than riscv here. What we probably want is to just make all the > declarations in include/linux/compat.h unconditional and not have them > depend on architecture specific macros. Some of these may have > incompatible prototypes depending on the architecture, but if we run > into those, I would suggest we just give them unique names. Thanks for the comments. With the other patch to kernel/sys_ni.c, this one is no longer needed, although I can look into making more entries in <linux/compat.h> unconditional. That would also mean adding them to kernel/sys_ni.c, right? (if not already there) -- ~Randy
