Message ID | 20241101160546.113259-1-mjeanson@efficios.com |
---|---|
State | New |
Headers | show |
Series | [v2] nptl: Add <thread_pointer.h> for sparc | expand |
On 2024-11-01 12:05, 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> > --- > Changes since v1: > - Remove the __builtin_thread_pointer code path, __has_builtin can't > reliably check if the builtin is implemented in the backend and > the latest GCC doesn't implement it. > --- > Cc: Florian Weimer <fweimer@redhat.com> > Cc: David S. Miller <davem@davemloft.net> > Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> > Cc: Andreas K. Hüttel <dilfridge@gentoo.org> > Cc: Arjun Shankar <arjun@redhat.com> > Cc: Adhemerval Zanella Netto <adhemerval.zanella@linaro.org> > --- > sysdeps/sparc/nptl/thread_pointer.h | 30 +++++++++++++++++++++++++++++ > 1 file changed, 30 insertions(+) > create mode 100644 sysdeps/sparc/nptl/thread_pointer.h > > diff --git a/sysdeps/sparc/nptl/thread_pointer.h b/sysdeps/sparc/nptl/thread_pointer.h > new file mode 100644 > index 0000000000..a526198057 > --- /dev/null > +++ b/sysdeps/sparc/nptl/thread_pointer.h > @@ -0,0 +1,30 @@ > +/* __thread_pointer definition. sparc 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__ ("mov %%g7, %0" : "=r" (__thread_register)); > + return __thread_register; > +} > + > +#endif /* _SYS_THREAD_POINTER_H */ Ping? I think this fixes the issue with v1. Anyone with hardware wants to test it? Michael
diff --git a/sysdeps/sparc/nptl/thread_pointer.h b/sysdeps/sparc/nptl/thread_pointer.h new file mode 100644 index 0000000000..a526198057 --- /dev/null +++ b/sysdeps/sparc/nptl/thread_pointer.h @@ -0,0 +1,30 @@ +/* __thread_pointer definition. sparc 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__ ("mov %%g7, %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> --- Changes since v1: - Remove the __builtin_thread_pointer code path, __has_builtin can't reliably check if the builtin is implemented in the backend and the latest GCC doesn't implement it. --- Cc: Florian Weimer <fweimer@redhat.com> Cc: David S. Miller <davem@davemloft.net> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Cc: Andreas K. Hüttel <dilfridge@gentoo.org> Cc: Arjun Shankar <arjun@redhat.com> Cc: Adhemerval Zanella Netto <adhemerval.zanella@linaro.org> --- sysdeps/sparc/nptl/thread_pointer.h | 30 +++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) create mode 100644 sysdeps/sparc/nptl/thread_pointer.h