On Wed, Nov 7, 2018 at 1:08 AM Palmer Dabbelt <[email protected]> wrote: > > On Mon, 05 Nov 2018 12:56:15 PST (-0800), Arnd Bergmann wrote: > > On 11/5/18, David Abdurachmanov <[email protected]> wrote: > >> Marcin Juszkiewicz reported issues while generating syscall table for riscv > >> using 4.20-rc1. The patch refactors our unistd.h files to match some other > >> architectures. > >> > >> - Add asm/unistd.h UAPI header, which has __ARCH_WANT_NEW_STAT > >> - Remove asm/syscalls.h UAPI header and merge to asm/unistd.h > >> - Adjust kernel asm/unistd.h > >> > >> So now asm/unistd.h UAPI header should show all syscalls for riscv. > >> > >> Before this, Makefile simply put `#include <asm-generic/unistd.h>` into > >> generated asm/unistd.h UAPI header thus user didn't see: > >> > >> - __NR_riscv_flush_icache > >> - __NR_newfstatat > >> - __NR_fstat > >> > >> which are supported by riscv kernel. > >> > >> Signed-off-by: David Abdurachmanov <[email protected]> > >> Cc: Arnd Bergmann <[email protected]> > >> Cc: Marcin Juszkiewicz <[email protected]> > >> Cc: Guenter Roeck <[email protected]> > > > > Thanks for addressing this, your patch correctly fixes riscv64, and > > I should have noticed the mistake when I originally merged the > > broken patch. > > > > However, looking closer I found another problem with the original > > patch that your fix does not address: > > > > __ARCH_WANT_NEW_STAT should only be set on 64-bit > > architectures. > > > > For a 32-bit architecture, we only want __ARCH_WANT_STAT64 if > > any. For 64-bit architectures with compat mode, we still need to > > set __ARCH_WANT_STAT64 from the non-uapi file so we get > > the syscall implementation. > > > > If we don't care about the riscv32 ABI changing yet, we can > > decide to leave out __ARCH_WANT_STAT64 here, and require > > glibc to implement it using statx() like any new architecture. > > stat64 is not y2038 safe, and statx replaces it because of that. > > Thanks for pointing this out. A while ago we decided the rv32 ABI was > "slushy": it can change if it has a good reason to. Right now the only > planned > changes are the y2038 changes, which I consider this a part of. For some > reason I thought we'd already done this, but since we haven't then I think it > should go in sooner rather than later -- that will help the glibc guys get > everything lined up. > > The target is still the next glibc release (Feb 1st) for a stable RV32I ABI. > That's progressing well, with one last blocking issue related to some of our > floating-point emulation routines before we can submit the port. This should > give us ample time to line up the ABIs correctly so everything works. > > So I think the correct answer here is to drop __ARCH_WANT_STAT64 from RISC-V. >
Then if you agree I could do and send v2: +#ifdef __LP64__ +#define __ARCH_WANT_NEW_STAT +#endif /* __LP64__ */ Cannot use CONFIG_64BIT as in user space nothing defines it. Alternatively I could check for __riscv_xlen == 64. I found _LP64 and __LP64__ being used in kernel, incl. include/uapi/linux/rseq.h david
