| Message ID | 20241101192339.123141-2-mjeanson@efficios.com |
|---|---|
| State | New |
| Headers | show |
| Series | nptl: Add <thread_pointer.h> for hppa | expand |
Okay. Tests pass on hppa. The __thread_pointer function is essentially the same as the __get_cr27 function in sysdeps/hppa/nptl/tls.h. I guess __get_cr27 could be eliminated with some cast adjustments if sysdeps/hppa/nptl/tls.h included this header. Dave On 2024-11-01 3:23 p.m., Michael Jeanson wrote: > This will be required by the rseq extensible ABI implementation on all > Linux architectures exposing the '__rseq_size' and '__rseq_offset' > symbols to set the initial value of the 'cpu_id' field which can be used > by applications to test if rseq is available and registered. As long as > the symbols are exposed it is valid for an application to perform this > test even if rseq is not yet implemented in libc for this architecture. > > Compile tested with build-many-glibcs.py but I don't have access to any > hardware to run the tests. > > Signed-off-by: Michael Jeanson <mjeanson@efficios.com> > --- > Cc: Florian Weimer <fweimer@redhat.com> > Cc: John David Anglin <danglin@gcc.gnu.org> > Cc: Carlos O'Donell <carlos@redhat.com> > --- > sysdeps/hppa/nptl/thread_pointer.h | 30 ++++++++++++++++++++++++++++++ > 1 file changed, 30 insertions(+) > create mode 100644 sysdeps/hppa/nptl/thread_pointer.h > > diff --git a/sysdeps/hppa/nptl/thread_pointer.h b/sysdeps/hppa/nptl/thread_pointer.h > new file mode 100644 > index 0000000000..96f5e9b4c0 > --- /dev/null > +++ b/sysdeps/hppa/nptl/thread_pointer.h > @@ -0,0 +1,30 @@ > +/* __thread_pointer definition. hppa version. > + Copyright (C) 2021-2024 Free Software Foundation, Inc. > + This file is part of the GNU C Library. > + > + The GNU C Library is free software; you can redistribute it and/or > + modify it under the terms of the GNU Lesser General Public > + License as published by the Free Software Foundation; either > + version 2.1 of the License, or (at your option) any later version. > + > + The GNU C Library is distributed in the hope that it will be useful, > + but WITHOUT ANY WARRANTY; without even the implied warranty of > + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU > + Lesser General Public License for more details. > + > + You should have received a copy of the GNU Lesser General Public > + License along with the GNU C Library. If not, see > + <https://www.gnu.org/licenses/>. */ > + > +#ifndef _SYS_THREAD_POINTER_H > +#define _SYS_THREAD_POINTER_H > + > +static inline void * > +__thread_pointer (void) > +{ > + void *__thread_register; > + __asm__ ("mfctl %%cr27, %0" : "=r" (__thread_register)); > + return __thread_register; > +} > + > +#endif /* _SYS_THREAD_POINTER_H */
On 2024-11-02 09:46, John David Anglin wrote: > Okay. Tests pass on hppa. > > The __thread_pointer function is essentially the same as the __get_cr27 function > in sysdeps/hppa/nptl/tls.h. I guess __get_cr27 could be eliminated with some cast > adjustments if sysdeps/hppa/nptl/tls.h included this header. > > Dave I'd be happy to send a follow up patch implementing this if it's something you are interested in. Thanks, Michael
diff --git a/sysdeps/hppa/nptl/thread_pointer.h b/sysdeps/hppa/nptl/thread_pointer.h new file mode 100644 index 0000000000..96f5e9b4c0 --- /dev/null +++ b/sysdeps/hppa/nptl/thread_pointer.h @@ -0,0 +1,30 @@ +/* __thread_pointer definition. hppa version. + Copyright (C) 2021-2024 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library. If not, see + <https://www.gnu.org/licenses/>. */ + +#ifndef _SYS_THREAD_POINTER_H +#define _SYS_THREAD_POINTER_H + +static inline void * +__thread_pointer (void) +{ + void *__thread_register; + __asm__ ("mfctl %%cr27, %0" : "=r" (__thread_register)); + return __thread_register; +} + +#endif /* _SYS_THREAD_POINTER_H */
This will be required by the rseq extensible ABI implementation on all Linux architectures exposing the '__rseq_size' and '__rseq_offset' symbols to set the initial value of the 'cpu_id' field which can be used by applications to test if rseq is available and registered. As long as the symbols are exposed it is valid for an application to perform this test even if rseq is not yet implemented in libc for this architecture. Compile tested with build-many-glibcs.py but I don't have access to any hardware to run the tests. Signed-off-by: Michael Jeanson <mjeanson@efficios.com> --- Cc: Florian Weimer <fweimer@redhat.com> Cc: John David Anglin <danglin@gcc.gnu.org> Cc: Carlos O'Donell <carlos@redhat.com> --- sysdeps/hppa/nptl/thread_pointer.h | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) create mode 100644 sysdeps/hppa/nptl/thread_pointer.h