nptl: Add <thread_pointer.h> for m68k

Message ID 20241023213529.578720-1-mjeanson@efficios.com
State Under Review
Delegated to: Arjun Shankar
Headers
Series nptl: Add <thread_pointer.h> for m68k |

Checks

Context Check Description
redhat-pt-bot/TryBot-apply_patch success Patch applied to master at the time it was sent
linaro-tcwg-bot/tcwg_glibc_build--master-aarch64 success Build passed
linaro-tcwg-bot/tcwg_glibc_check--master-aarch64 success Test passed
linaro-tcwg-bot/tcwg_glibc_build--master-arm success Build passed
redhat-pt-bot/TryBot-32bit fail Patch caused testsuite regressions
linaro-tcwg-bot/tcwg_glibc_check--master-arm success Test passed

Commit Message

Michael Jeanson Oct. 23, 2024, 9:35 p.m. UTC
  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: Andreas Schwab <schwab@linux-m68k.org>
Cc: Andreas K. Hüttel <dilfridge@gentoo.org>
---
 sysdeps/m68k/nptl/thread_pointer.h | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)
 create mode 100644 sysdeps/m68k/nptl/thread_pointer.h
  

Comments

Arjun Shankar Oct. 30, 2024, 3:07 p.m. UTC | #1
Hi Michael,

> 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: Andreas Schwab <schwab@linux-m68k.org>
> Cc: Andreas K. Hüttel <dilfridge@gentoo.org>

I don't have access to this hardware, but I reviewed this for being
reasonable and verified that it passes build-many-glibcs for m68k
(which I tested as well).

Reviewed-by: Arjun Shankar <arjun@redhat.com>

> ---
>  sysdeps/m68k/nptl/thread_pointer.h | 30 ++++++++++++++++++++++++++++++
>  1 file changed, 30 insertions(+)
>  create mode 100644 sysdeps/m68k/nptl/thread_pointer.h
>
> diff --git a/sysdeps/m68k/nptl/thread_pointer.h b/sysdeps/m68k/nptl/thread_pointer.h
> new file mode 100644
> index 0000000000..08df6a8ac4
> --- /dev/null
> +++ b/sysdeps/m68k/nptl/thread_pointer.h
> @@ -0,0 +1,30 @@
> +/* __thread_pointer definition.  m68k version.
> +   Copyright (C) 2021-2024 Free Software Foundation, Inc.

OK. Looks very similar to the other thread_pointer.h files, so I guess
as a slightly modified "copy", the 2021-2024 copyright line is fine.

> +   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

OK. Matches other files.

> +
> +extern void * __m68k_read_tp (void);

OK. Corresponds to a get_thread_area system call.

> +
> +static inline void *
> +__thread_pointer (void)
> +{
> +  return __m68k_read_tp ();
> +}

OK. Call it. Looks reasonable to me.

> +
> +#endif /* _SYS_THREAD_POINTER_H */

OK.

> --
> 2.43.0
>
  

Patch

diff --git a/sysdeps/m68k/nptl/thread_pointer.h b/sysdeps/m68k/nptl/thread_pointer.h
new file mode 100644
index 0000000000..08df6a8ac4
--- /dev/null
+++ b/sysdeps/m68k/nptl/thread_pointer.h
@@ -0,0 +1,30 @@ 
+/* __thread_pointer definition.  m68k 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
+
+extern void * __m68k_read_tp (void);
+
+static inline void *
+__thread_pointer (void)
+{
+  return __m68k_read_tp ();
+}
+
+#endif /* _SYS_THREAD_POINTER_H */