| Message ID | 20180112160704.20107-1-tuliom@linux.vnet.ibm.com |
|---|---|
| State | New |
| Headers | show |
| Series | [PATCHv2] powerpc: Fix syscalls during early process initialization [BZ #22685] | expand |
On 01/12/2018 05:07 PM, Tulio Magno Quites Machado Filho wrote: > +/* __access_noerrno is used during process initialization in elf/dl-tunables.c > + before the TCB is initialized, prohibiting the usage of > + ABORT_TRANSACTION. */ > +#undef ABORT_TRANSACTION > +#define ABORT_TRANSACTION > + > +#include "sysdeps/unix/sysv/linux/not-errno.h" This #define isn't properly scoped, so I really don't like this approach for a header file. Thanks, Florian
Florian Weimer <fweimer@redhat.com> writes: > On 01/12/2018 05:07 PM, Tulio Magno Quites Machado Filho wrote: >> +/* __access_noerrno is used during process initialization in elf/dl-tunables.c >> + before the TCB is initialized, prohibiting the usage of >> + ABORT_TRANSACTION. */ >> +#undef ABORT_TRANSACTION >> +#define ABORT_TRANSACTION >> + >> +#include "sysdeps/unix/sysv/linux/not-errno.h" > > This #define isn't properly scoped, so I really don't like this approach > for a header file. Do you think that checking for TUNABLES_INTERNAL would be enough?
On 01/12/2018 05:40 PM, Tulio Magno Quites Machado Filho wrote: > Florian Weimer <fweimer@redhat.com> writes: > >> On 01/12/2018 05:07 PM, Tulio Magno Quites Machado Filho wrote: >>> +/* __access_noerrno is used during process initialization in elf/dl-tunables.c >>> + before the TCB is initialized, prohibiting the usage of >>> + ABORT_TRANSACTION. */ >>> +#undef ABORT_TRANSACTION >>> +#define ABORT_TRANSACTION >>> + >>> +#include "sysdeps/unix/sysv/linux/not-errno.h" >> >> This #define isn't properly scoped, so I really don't like this approach >> for a header file. > > Do you think that checking for TUNABLES_INTERNAL would be enough? I'm not sure what you mean. If you move the current definition of ABORT_TRANSACTION to ABORT_TRANSACTION_IMPL, you could perhaps do #undef ABORT_TRANSACTION #define ABORT_TRANSACTION #include "sysdeps/unix/sysv/linux/not-errno.h" #undef ABORT_TRANSACTION #define ABORT_TRANSACTION ABORT_TRANSACTION_IMPL (with comments, obviously). Thanks, Florian
diff --git a/sysdeps/unix/sysv/linux/powerpc/not-errno.h b/sysdeps/unix/sysv/linux/powerpc/not-errno.h new file mode 100644 index 0000000..642cb8a --- /dev/null +++ b/sysdeps/unix/sysv/linux/powerpc/not-errno.h @@ -0,0 +1,25 @@ +/* Syscall wrapper that do not set errno. Linux powerpc version. + Copyright (C) 2018 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 + <http://www.gnu.org/licenses/>. */ + +/* __access_noerrno is used during process initialization in elf/dl-tunables.c + before the TCB is initialized, prohibiting the usage of + ABORT_TRANSACTION. */ +#undef ABORT_TRANSACTION +#define ABORT_TRANSACTION + +#include "sysdeps/unix/sysv/linux/not-errno.h"
Changes since v1: - Re-implemented the patch to re-define a powerpc-specific __access_noerrno. --- 8< --- The tunables framework needs to execute syscall early in process initialization, before the TCB is available for consumption. This behavior conflicts with powerpc{|64|64le}'s lock elision code, that checks the TCB before trying to abort transactions immediately before executing a syscall. This patch adds a powerpc-specific implementation of __access_noerrno that does not abort transactions before the executing syscall. Tested on powerpc{|64|64le}. 2018-01-12 Tulio Magno Quites Machado Filho <tuliom@linux.vnet.ibm.com> [BZ #22685] * sysdeps/unix/sysv/linux/powerpc/not-errno.h: New file. Reuse Linux code, but remove the code that aborts transactions. Signed-off-by: Tulio Magno Quites Machado Filho <tuliom@linux.vnet.ibm.com> Tested-by: Aurelien Jarno <aurelien@aurel32.net> --- sysdeps/unix/sysv/linux/powerpc/not-errno.h | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) create mode 100644 sysdeps/unix/sysv/linux/powerpc/not-errno.h