From 4612268a0ad8e3409d8ce2314dd2dd8ee0af5269 Mon Sep 17 00:00:00 2001 From: Tulio Magno Quites Machado Filho Date: Fri, 12 Jan 2018 18:50:33 -0200 Subject: powerpc: Fix syscalls during early process initialization [BZ #22685] 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}. [BZ #22685] * sysdeps/powerpc/powerpc32/sysdep.h (ABORT_TRANSACTION_IMPL): Renamed from ABORT_TRANSACTION. (ABORT_TRANSACTION): Redirect to ABORT_TRANSACTION_IMPL. * sysdeps/powerpc/powerpc64/sysdep.h (ABORT_TRANSACTION, ABORT_TRANSACTION_IMPL): Likewise. * 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 Tested-by: Aurelien Jarno --- sysdeps/unix/sysv/linux/powerpc/not-errno.h | 30 +++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) create mode 100644 sysdeps/unix/sysv/linux/powerpc/not-errno.h (limited to 'sysdeps/unix') 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..27da21b --- /dev/null +++ b/sysdeps/unix/sysv/linux/powerpc/not-errno.h @@ -0,0 +1,30 @@ +/* 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 + . */ + +/* __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" + +/* Recover ABORT_TRANSACTION's previous value, in order to not affect + other syscalls. */ +#undef ABORT_TRANSACTION +#define ABORT_TRANSACTION ABORT_TRANSACTION_IMPL -- cgit v1.1