On Thu, Mar 18, 2021 at 04:14:44PM +0100, Christian Brauner wrote:
> On Thu, Mar 18, 2021 at 08:02:30AM -0700, Darrick J. Wong wrote:
> > On Thu, Mar 18, 2021 at 07:23:10AM +0100, Christoph Hellwig wrote:
> > > > +/* open_tree() */
> > > > +#ifndef OPEN_TREE_CLONE
> > > > +#define OPEN_TREE_CLONE 1
> > > > +#endif
> > > > +
> > > > +#ifndef OPEN_TREE_CLOEXEC
> > > > +#define OPEN_TREE_CLOEXEC O_CLOEXEC
> > > > +#endif
> > > > +
> > > > +#ifndef __NR_open_tree
> > > > + #if defined __alpha__
> > > > + #define __NR_open_tree 538
> > > > + #elif defined _MIPS_SIM
> > > > + #if _MIPS_SIM == _MIPS_SIM_ABI32 /* o32 */
> > > > + #define __NR_open_tree 4428
> > > > + #endif
> > > > + #if _MIPS_SIM == _MIPS_SIM_NABI32 /* n32 */
> > > > + #define __NR_open_tree 6428
> > > > + #endif
> > > > + #if _MIPS_SIM == _MIPS_SIM_ABI64 /* n64 */
> > > > + #define __NR_open_tree 5428
> > > > + #endif
> > > > + #elif defined __ia64__
> > > > + #define __NR_open_tree (428 + 1024)
> > > > + #else
> > > > + #define __NR_open_tree 428
> > > > + #endif
> > > > +#endif
> > > > +
> > > > +/* move_mount() */
> > > > +#ifndef MOVE_MOUNT_F_EMPTY_PATH
> > > > +#define MOVE_MOUNT_F_EMPTY_PATH 0x00000004 /* Empty from path permitted */
> > > > +#endif
> > > > +
> > > > +#ifndef __NR_move_mount
> > > > + #if defined __alpha__
> > > > + #define __NR_move_mount 539
> > > > + #elif defined _MIPS_SIM
> > > > + #if _MIPS_SIM == _MIPS_SIM_ABI32 /* o32 */
> > > > + #define __NR_move_mount 4429
> > > > + #endif
> > > > + #if _MIPS_SIM == _MIPS_SIM_NABI32 /* n32 */
> > > > + #define __NR_move_mount 6429
> > > > + #endif
> > > > + #if _MIPS_SIM == _MIPS_SIM_ABI64 /* n64 */
> > > > + #define __NR_move_mount 5429
> > > > + #endif
> > > > + #elif defined __ia64__
> > > > + #define __NR_move_mount (428 + 1024)
> > > > + #else
> > > > + #define __NR_move_mount 429
> > > > + #endif
> > > > +#endif
> > > > +
> > > > +static inline int sys_open_tree(int dfd, const char *filename, unsigned int flags)
> > > > +{
> > > > + return syscall(__NR_open_tree, dfd, filename, flags);
> > > > +}
> > > > +
> > > > +static inline int sys_move_mount(int from_dfd, const char *from_pathname, int to_dfd,
> > > > + const char *to_pathname, unsigned int flags)
> > > > +{
> > > > + return syscall(__NR_move_mount, from_dfd, from_pathname, to_dfd, to_pathname, flags);
> > > > +}
> > >
> > > Not directly new in your patch, but I wish we'd have a central header
> > > for missing UAPI bits in xfstests instead of spreading it over
> > > various files.
> >
> > FWIW if you (or anyone else) /does/ create a src/linux_calls.h or
> > similar for things like this, I will totally start adding things to it
> > instead of scattering them everywhere. :)
>
> I do usually have in my C projects two .h files (without corresponding
> .c files):
>
> 1. syscall_numbers.h
> https://github.com/lxc/lxc/blob/master/src/lxc/syscall_numbers.h
>
> Where syscall_numbers defines the missing syscall numbers. For new
> syscalls in the style exhibited in this patch and for legacy syscalls
> it's a bit more nasty (i.e. syscalls before we unified numbering [apart
> from alpha]):
>
> #ifndef __NR_memfd_create
> #if defined __i386__
> #define __NR_memfd_create 356
> #elif defined __x86_64__
> #define __NR_memfd_create 319
> #elif defined __arm__
> #define __NR_memfd_create 385
> #elif defined __aarch64__
> #define __NR_memfd_create 279
> #elif defined __s390__
> #define __NR_memfd_create 350
> #elif defined __powerpc__
> #define __NR_memfd_create 360
> #elif defined __riscv
> #define __NR_memfd_create 279
> #elif defined __sparc__
> #define __NR_memfd_create 348
> #elif defined __blackfin__
> #define __NR_memfd_create 390
> #elif defined __ia64__
> #define __NR_memfd_create 1340
> #elif defined _MIPS_SIM
> #if _MIPS_SIM == _MIPS_SIM_ABI32
> #define __NR_memfd_create 4354
> #endif
> #if _MIPS_SIM == _MIPS_SIM_NABI32
> #define __NR_memfd_create 6318
> #endif
> #if _MIPS_SIM == _MIPS_SIM_ABI64
> #define __NR_memfd_create 5314
> #endif
> #else
> #define -1
> #warning "__NR_memfd_create not defined for your architecture"
> #endif
> #endif
>
> 2. syscall_wrappers.h
> https://github.com/lxc/lxc/blob/master/src/lxc/syscall_wrappers.h
>
> Where syscall_wrappers.h defines minimal wrappers for missing
> syscalls and their corresponding types.
>
> #ifndef HAVE_SYS_SIGNALFD_H
> struct signalfd_siginfo {
> uint32_t ssi_signo;
> int32_t ssi_errno;
> int32_t ssi_code;
> uint32_t ssi_pid;
> uint32_t ssi_uid;
> int32_t ssi_fd;
> uint32_t ssi_tid;
> uint32_t ssi_band;
> uint32_t ssi_overrun;
> uint32_t ssi_trapno;
> int32_t ssi_status;
> int32_t ssi_int;
> uint64_t ssi_ptr;
> uint64_t ssi_utime;
> uint64_t ssi_stime;
> uint64_t ssi_addr;
> uint8_t __pad[48];
> };
>
> static inline int signalfd(int fd, const sigset_t *mask, int flags)
> {
> int retval;
>
> retval = syscall(__NR_signalfd4, fd, mask, _NSIG / 8, flags);
> #ifdef __NR_signalfd
> if (errno == ENOSYS && flags == 0)
> retval = syscall(__NR_signalfd, fd, mask, _NSIG / 8);
> #endif
>
> return retval;
> }
> #endif
>
> Something like this might also work for xfstests.
Yeah, not 5 minutes later someone emailed me a bug report that fstests
doesn't build on Ubuntu 16.04 due to its kernel headers not knowing
about fsxattr, so I guess I'll have a patch out adding this exact header
file later today.
--D
>
> Christian
