Re: [PATCH v2 0/3] Support --enable-newlib-reent-thread-local Newlib configuration option
On 21.07.22 10:36, Chris Johns wrote: On 21/7/2022 6:30 pm, Sebastian Huber wrote: On 21.07.22 10:27, Chris Johns wrote: On 21/7/2022 6:21 pm, Sebastian Huber wrote: On 21.07.22 10:16, Chris Johns wrote: On 21/7/2022 6:11 pm, Sebastian Huber wrote: On 21.07.22 10:03, Chris Johns wrote: As an aside, does gdb know about TLS variables and so will `errno` be visible? Good question, there seems to be some support missing. For example for arm/xilinx_zynq_a9_qemu: Breakpoint 7, Init (ignored=2118804) at /home/EB/sebastian_h/src/rtems/testsuites/samples/fileio/init.c:1169 1169 TEST_BEGIN(); (gdb) watch _tls_errno Cannot find thread-local variables on this target (gdb) p _tls_errno Cannot find thread-local variables on this target I wonder if we need to configure gdb so it understands how we handle TLS variables? It could be a Qemu issue. In GDB there is a /* Check for the TLS register feature. */ feature = tdesc_find_feature (tdesc, "org.gnu.gdb.arm.tls"); However, this is not provided by Qemu. Is this something in the remote protocol? I would have thought the ABI would define the register? Yes, I guess this is a part of the machine description provided by the server (Qemu). This stuff seems to be quite new (from 2022) added by John Baldwin for FreeBSD. That would only apply if qemu was providing the XML description and it is not normally something I have seen. Most of time the built in XML is used. The only packet I could see in a quick look at the protocol is offsets for TLS variables for dynamically loaded object files. This is needed because the link editor allocates the variables when relocating. Maybe this feature is not included in GDB 12 and earlier? -- embedded brains GmbH Herr Sebastian HUBER Dornierstr. 4 82178 Puchheim Germany email: sebastian.hu...@embedded-brains.de phone: +49-89-18 94 741 - 16 fax: +49-89-18 94 741 - 08 Registergericht: Amtsgericht München Registernummer: HRB 157899 Vertretungsberechtigte Geschäftsführer: Peter Rasmussen, Thomas Dörfler Unsere Datenschutzerklärung finden Sie hier: https://embedded-brains.de/datenschutzerklaerung/ ___ devel mailing list devel@rtems.org http://lists.rtems.org/mailman/listinfo/devel
Re: [PATCH v2 0/3] Support --enable-newlib-reent-thread-local Newlib configuration option
On 21/7/2022 6:30 pm, Sebastian Huber wrote: > On 21.07.22 10:27, Chris Johns wrote: >> On 21/7/2022 6:21 pm, Sebastian Huber wrote: >>> On 21.07.22 10:16, Chris Johns wrote: On 21/7/2022 6:11 pm, Sebastian Huber wrote: > On 21.07.22 10:03, Chris Johns wrote: >> As an aside, does gdb know about TLS variables and so will `errno` be >> visible? > Good question, there seems to be some support missing. For example for > arm/xilinx_zynq_a9_qemu: > > Breakpoint 7, Init (ignored=2118804) at > /home/EB/sebastian_h/src/rtems/testsuites/samples/fileio/init.c:1169 > 1169 TEST_BEGIN(); > (gdb) watch _tls_errno > Cannot find thread-local variables on this target > (gdb) p _tls_errno > Cannot find thread-local variables on this target I wonder if we need to configure gdb so it understands how we handle TLS variables? >>> It could be a Qemu issue. In GDB there is a >>> >>> /* Check for the TLS register feature. */ >>> feature = tdesc_find_feature (tdesc, "org.gnu.gdb.arm.tls"); >>> >>> However, this is not provided by Qemu. >> Is this something in the remote protocol? I would have thought the ABI would >> define the register? > > Yes, I guess this is a part of the machine description provided by the server > (Qemu). This stuff seems to be quite new (from 2022) added by John Baldwin for > FreeBSD. That would only apply if qemu was providing the XML description and it is not normally something I have seen. Most of time the built in XML is used. The only packet I could see in a quick look at the protocol is offsets for TLS variables for dynamically loaded object files. This is needed because the link editor allocates the variables when relocating. Chris ___ devel mailing list devel@rtems.org http://lists.rtems.org/mailman/listinfo/devel
Re: [PATCH v2 0/3] Support --enable-newlib-reent-thread-local Newlib configuration option
On 21.07.22 10:27, Chris Johns wrote: On 21/7/2022 6:21 pm, Sebastian Huber wrote: On 21.07.22 10:16, Chris Johns wrote: On 21/7/2022 6:11 pm, Sebastian Huber wrote: On 21.07.22 10:03, Chris Johns wrote: As an aside, does gdb know about TLS variables and so will `errno` be visible? Good question, there seems to be some support missing. For example for arm/xilinx_zynq_a9_qemu: Breakpoint 7, Init (ignored=2118804) at /home/EB/sebastian_h/src/rtems/testsuites/samples/fileio/init.c:1169 1169 TEST_BEGIN(); (gdb) watch _tls_errno Cannot find thread-local variables on this target (gdb) p _tls_errno Cannot find thread-local variables on this target I wonder if we need to configure gdb so it understands how we handle TLS variables? It could be a Qemu issue. In GDB there is a /* Check for the TLS register feature. */ feature = tdesc_find_feature (tdesc, "org.gnu.gdb.arm.tls"); However, this is not provided by Qemu. Is this something in the remote protocol? I would have thought the ABI would define the register? Yes, I guess this is a part of the machine description provided by the server (Qemu). This stuff seems to be quite new (from 2022) added by John Baldwin for FreeBSD. -- embedded brains GmbH Herr Sebastian HUBER Dornierstr. 4 82178 Puchheim Germany email: sebastian.hu...@embedded-brains.de phone: +49-89-18 94 741 - 16 fax: +49-89-18 94 741 - 08 Registergericht: Amtsgericht München Registernummer: HRB 157899 Vertretungsberechtigte Geschäftsführer: Peter Rasmussen, Thomas Dörfler Unsere Datenschutzerklärung finden Sie hier: https://embedded-brains.de/datenschutzerklaerung/ ___ devel mailing list devel@rtems.org http://lists.rtems.org/mailman/listinfo/devel
Re: [PATCH v2 0/3] Support --enable-newlib-reent-thread-local Newlib configuration option
On 21/7/2022 6:21 pm, Sebastian Huber wrote: > On 21.07.22 10:16, Chris Johns wrote: >> On 21/7/2022 6:11 pm, Sebastian Huber wrote: >>> On 21.07.22 10:03, Chris Johns wrote: As an aside, does gdb know about TLS variables and so will `errno` be visible? >>> Good question, there seems to be some support missing. For example for >>> arm/xilinx_zynq_a9_qemu: >>> >>> Breakpoint 7, Init (ignored=2118804) at >>> /home/EB/sebastian_h/src/rtems/testsuites/samples/fileio/init.c:1169 >>> 1169 TEST_BEGIN(); >>> (gdb) watch _tls_errno >>> Cannot find thread-local variables on this target >>> (gdb) p _tls_errno >>> Cannot find thread-local variables on this target >> I wonder if we need to configure gdb so it understands how we handle TLS >> variables? > > It could be a Qemu issue. In GDB there is a > > /* Check for the TLS register feature. */ > feature = tdesc_find_feature (tdesc, "org.gnu.gdb.arm.tls"); > > However, this is not provided by Qemu. Is this something in the remote protocol? I would have thought the ABI would define the register? Chris ___ devel mailing list devel@rtems.org http://lists.rtems.org/mailman/listinfo/devel
Re: [PATCH v2 0/3] Support --enable-newlib-reent-thread-local Newlib configuration option
On 21.07.22 10:16, Chris Johns wrote: On 21/7/2022 6:11 pm, Sebastian Huber wrote: On 21.07.22 10:03, Chris Johns wrote: As an aside, does gdb know about TLS variables and so will `errno` be visible? Good question, there seems to be some support missing. For example for arm/xilinx_zynq_a9_qemu: Breakpoint 7, Init (ignored=2118804) at /home/EB/sebastian_h/src/rtems/testsuites/samples/fileio/init.c:1169 1169 TEST_BEGIN(); (gdb) watch _tls_errno Cannot find thread-local variables on this target (gdb) p _tls_errno Cannot find thread-local variables on this target I wonder if we need to configure gdb so it understands how we handle TLS variables? It could be a Qemu issue. In GDB there is a /* Check for the TLS register feature. */ feature = tdesc_find_feature (tdesc, "org.gnu.gdb.arm.tls"); However, this is not provided by Qemu. -- embedded brains GmbH Herr Sebastian HUBER Dornierstr. 4 82178 Puchheim Germany email: sebastian.hu...@embedded-brains.de phone: +49-89-18 94 741 - 16 fax: +49-89-18 94 741 - 08 Registergericht: Amtsgericht München Registernummer: HRB 157899 Vertretungsberechtigte Geschäftsführer: Peter Rasmussen, Thomas Dörfler Unsere Datenschutzerklärung finden Sie hier: https://embedded-brains.de/datenschutzerklaerung/ ___ devel mailing list devel@rtems.org http://lists.rtems.org/mailman/listinfo/devel
Re: [PATCH v2 0/3] Support --enable-newlib-reent-thread-local Newlib configuration option
On 21/7/2022 6:11 pm, Sebastian Huber wrote: > On 21.07.22 10:03, Chris Johns wrote: >> As an aside, does gdb know about TLS variables and so will `errno` be >> visible? > > Good question, there seems to be some support missing. For example for > arm/xilinx_zynq_a9_qemu: > > Breakpoint 7, Init (ignored=2118804) at > /home/EB/sebastian_h/src/rtems/testsuites/samples/fileio/init.c:1169 > 1169 TEST_BEGIN(); > (gdb) watch _tls_errno > Cannot find thread-local variables on this target > (gdb) p _tls_errno > Cannot find thread-local variables on this target I wonder if we need to configure gdb so it understands how we handle TLS variables? Chris ___ devel mailing list devel@rtems.org http://lists.rtems.org/mailman/listinfo/devel
Re: [PATCH v2 0/3] Support --enable-newlib-reent-thread-local Newlib configuration option
On 21.07.22 10:03, Chris Johns wrote: As an aside, does gdb know about TLS variables and so will `errno` be visible? Good question, there seems to be some support missing. For example for arm/xilinx_zynq_a9_qemu: Breakpoint 7, Init (ignored=2118804) at /home/EB/sebastian_h/src/rtems/testsuites/samples/fileio/init.c:1169 1169 TEST_BEGIN(); (gdb) watch _tls_errno Cannot find thread-local variables on this target (gdb) p _tls_errno Cannot find thread-local variables on this target -- embedded brains GmbH Herr Sebastian HUBER Dornierstr. 4 82178 Puchheim Germany email: sebastian.hu...@embedded-brains.de phone: +49-89-18 94 741 - 16 fax: +49-89-18 94 741 - 08 Registergericht: Amtsgericht München Registernummer: HRB 157899 Vertretungsberechtigte Geschäftsführer: Peter Rasmussen, Thomas Dörfler Unsere Datenschutzerklärung finden Sie hier: https://embedded-brains.de/datenschutzerklaerung/ ___ devel mailing list devel@rtems.org http://lists.rtems.org/mailman/listinfo/devel
Re: [PATCH v2 0/3] Support --enable-newlib-reent-thread-local Newlib configuration option
+1 Really great patch and change. I think the performance improvements will be excellent. As an aside, does gdb know about TLS variables and so will `errno` be visible? Chris On 21/7/2022 5:09 pm, Sebastian Huber wrote: > This patch set adds support for the --enable-newlib-reent-thread-local > (_REENT_THREAD_LOCAL_STORAGE) Newlib configuration option. > > By default, Newlib uses a huge object of type struct _reent to store > thread-specific data. This object is returned by __getreent() if the > __DYNAMIC_REENT__ Newlib configuration option is defined. > > The reentrancy structure contains for example errno and the standard input, > output, and error file streams. This means that if an application only uses > errno it has a dependency on the file stream support even if it does not use > it. This is an issue for lower end targets and applications which need to > qualify the software according to safety standards (for example ECSS-E-ST-40C, > ECSS-Q-ST-80C, IEC 61508, ISO 26262, DO-178, DO-330, DO-333). > > If the new _REENT_THREAD_LOCAL configuration option is enabled, then struct > _reent is replaced by dedicated thread-local objects for each struct _reent > member. The thread-local objects are defined in translation units which use > the corresponding object. > > v2: > > * Remove i386, microblaze, and m68k from default enabled list. > > * Support --with-newlib-tls and --without-newlib-tls. > > Sebastian Huber (3): > 6/7: Update Newlib > newlib: Support --with/without-newlib-tls > 6/7: Use TLS in Newlib for some targets by default > > rtems/config/6/rtems-aarch64.bset | 1 + > rtems/config/6/rtems-arm.bset | 1 + > rtems/config/6/rtems-nios2.bset | 1 + > rtems/config/6/rtems-powerpc.bset | 1 + > rtems/config/6/rtems-riscv.bset | 1 + > rtems/config/6/rtems-sparc.bset | 1 + > rtems/config/7/rtems-aarch64.bset | 1 + > rtems/config/7/rtems-arm.bset | 1 + > rtems/config/7/rtems-nios2.bset | 1 + > rtems/config/7/rtems-powerpc.bset | 1 + > rtems/config/7/rtems-riscv.bset | 1 + > rtems/config/7/rtems-sparc.bset | 1 + > .../config/tools/rtems-gcc-10-newlib-head.cfg | 4 +-- > .../tools/rtems-gcc-10.4-newlib-head.cfg | 27 +++ > .../config/tools/rtems-gcc-12-newlib-head.cfg | 5 ++-- > .../tools/rtems-gcc-head-newlib-head.cfg | 4 +-- > source-builder/config/checks.cfg | 9 +++ > source-builder/config/gcc-common-1.cfg| 1 + > 18 files changed, 55 insertions(+), 7 deletions(-) > create mode 100644 rtems/config/tools/rtems-gcc-10.4-newlib-head.cfg > ___ devel mailing list devel@rtems.org http://lists.rtems.org/mailman/listinfo/devel
[PATCH v2 0/3] Support --enable-newlib-reent-thread-local Newlib configuration option
This patch set adds support for the --enable-newlib-reent-thread-local (_REENT_THREAD_LOCAL_STORAGE) Newlib configuration option. By default, Newlib uses a huge object of type struct _reent to store thread-specific data. This object is returned by __getreent() if the __DYNAMIC_REENT__ Newlib configuration option is defined. The reentrancy structure contains for example errno and the standard input, output, and error file streams. This means that if an application only uses errno it has a dependency on the file stream support even if it does not use it. This is an issue for lower end targets and applications which need to qualify the software according to safety standards (for example ECSS-E-ST-40C, ECSS-Q-ST-80C, IEC 61508, ISO 26262, DO-178, DO-330, DO-333). If the new _REENT_THREAD_LOCAL configuration option is enabled, then struct _reent is replaced by dedicated thread-local objects for each struct _reent member. The thread-local objects are defined in translation units which use the corresponding object. v2: * Remove i386, microblaze, and m68k from default enabled list. * Support --with-newlib-tls and --without-newlib-tls. Sebastian Huber (3): 6/7: Update Newlib newlib: Support --with/without-newlib-tls 6/7: Use TLS in Newlib for some targets by default rtems/config/6/rtems-aarch64.bset | 1 + rtems/config/6/rtems-arm.bset | 1 + rtems/config/6/rtems-nios2.bset | 1 + rtems/config/6/rtems-powerpc.bset | 1 + rtems/config/6/rtems-riscv.bset | 1 + rtems/config/6/rtems-sparc.bset | 1 + rtems/config/7/rtems-aarch64.bset | 1 + rtems/config/7/rtems-arm.bset | 1 + rtems/config/7/rtems-nios2.bset | 1 + rtems/config/7/rtems-powerpc.bset | 1 + rtems/config/7/rtems-riscv.bset | 1 + rtems/config/7/rtems-sparc.bset | 1 + .../config/tools/rtems-gcc-10-newlib-head.cfg | 4 +-- .../tools/rtems-gcc-10.4-newlib-head.cfg | 27 +++ .../config/tools/rtems-gcc-12-newlib-head.cfg | 5 ++-- .../tools/rtems-gcc-head-newlib-head.cfg | 4 +-- source-builder/config/checks.cfg | 9 +++ source-builder/config/gcc-common-1.cfg| 1 + 18 files changed, 55 insertions(+), 7 deletions(-) create mode 100644 rtems/config/tools/rtems-gcc-10.4-newlib-head.cfg -- 2.35.3 ___ devel mailing list devel@rtems.org http://lists.rtems.org/mailman/listinfo/devel
