diff options
| -rw-r--r-- | sysdeps/unix/sysv/linux/aarch64/nptl/pt-vfork.S | 35 | ||||
| -rw-r--r-- | sysdeps/unix/sysv/linux/aarch64/pt-vfork.c | 54 | ||||
| -rw-r--r-- | sysdeps/unix/sysv/linux/aarch64/vfork.S | 29 |
3 files changed, 74 insertions, 44 deletions
diff --git a/sysdeps/unix/sysv/linux/aarch64/nptl/pt-vfork.S b/sysdeps/unix/sysv/linux/aarch64/nptl/pt-vfork.S deleted file mode 100644 index 2108347..0000000 --- a/sysdeps/unix/sysv/linux/aarch64/nptl/pt-vfork.S +++ /dev/null @@ -1,35 +0,0 @@ -/* Copyright (C) 2009-2014 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/>. */ - -#include <tcb-offsets.h> - -/* Save the PID value. */ -#define SAVE_PID \ - mrs x2, tpidr_el0; \ - sub x2, x2, #PTHREAD_SIZEOF; \ - ldr w3, [x2, #PTHREAD_PID_OFFSET]; \ - neg w0, w3; \ - str w0, [x2, #PTHREAD_PID_OFFSET] - -/* Restore the old PID value in the parent. */ -#define RESTORE_PID \ - cbz x0, 1f; \ - str w3, [x2, #PTHREAD_PID_OFFSET]; \ -1: - -#include "../vfork.S" diff --git a/sysdeps/unix/sysv/linux/aarch64/pt-vfork.c b/sysdeps/unix/sysv/linux/aarch64/pt-vfork.c new file mode 100644 index 0000000..5dd23bf --- /dev/null +++ b/sysdeps/unix/sysv/linux/aarch64/pt-vfork.c @@ -0,0 +1,54 @@ +/* vfork ABI-compatibility entry points for libpthread. + Copyright (C) 2014 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/>. */ + +#include <shlib-compat.h> + +/* libpthread used to have its own vfork implementation that differed + from libc's only in having a pointless micro-optimization. There + is no longer any use to having a separate copy in libpthread, but + the historical ABI requires it. For static linking, there is no + need to provide anything here--the libc version will be linked in. + For shared library ABI compatibility, there must be __vfork and + vfork symbols in libpthread.so. */ + +#if HAVE_IFUNC +# include <nptl/pt-vfork.c> +#elif (SHLIB_COMPAT (libpthread, GLIBC_2_0, GLIBC_2_20) \ + || SHLIB_COMPAT (libpthread, GLIBC_2_1_2, GLIBC_2_20)) + +/* Thankfully, on AArch64 we can rely on the compiler generating + a tail call here. */ + +extern void __libc_vfork (void); + +void +vfork_compat (void) +{ + __libc_vfork (); +} + +# if SHLIB_COMPAT (libpthread, GLIBC_2_0, GLIBC_2_20) +compat_symbol (libpthread, vfork_compat, vfork, GLIBC_2_0); +# endif + +# if SHLIB_COMPAT (libpthread, GLIBC_2_1_2, GLIBC_2_20) +strong_alias (vfork_compat, vfork_compat2) +compat_symbol (libpthread, vfork_compat2, __vfork, GLIBC_2_1_2); +# endif + +#endif diff --git a/sysdeps/unix/sysv/linux/aarch64/vfork.S b/sysdeps/unix/sysv/linux/aarch64/vfork.S index d9f2c70..316cb65 100644 --- a/sysdeps/unix/sysv/linux/aarch64/vfork.S +++ b/sysdeps/unix/sysv/linux/aarch64/vfork.S @@ -28,22 +28,33 @@ ENTRY (__vfork) -#ifdef SAVE_PID - SAVE_PID -#endif + /* Save the TCB-cached PID away in w3, and then negate the TCB + field. But if it's zero, set it to 0x80000000 instead. See + raise.c for the logic that relies on this value. */ + mrs x2, tpidr_el0 + sub x2, x2, #PTHREAD_SIZEOF + ldr w3, [x2, #PTHREAD_PID_OFFSET] + mov w1, #0x80000000 + negs w0, w3 + csel w0, w1, w0, eq + str w0, [x2, #PTHREAD_PID_OFFSET] + mov x0, #0x4111 /* CLONE_VM | CLONE_VFORK | SIGCHLD */ mov x1, sp DO_CALL (clone, 2) -#ifdef RESTORE_PID - RESTORE_PID -#endif + + /* Restore the original value of the TCB cache of the PID, if we're + the parent. But in the child (syscall return value equals zero), + leave things as they are. */ + cbz x0, 1f + str w3, [x2, #PTHREAD_PID_OFFSET] +1: cmn x0, #4095 - b.cs 1f + b.cs .Lsyscall_error RET -1: - b SYSCALL_ERROR PSEUDO_END (__vfork) libc_hidden_def (__vfork) weak_alias (__vfork, vfork) +strong_alias (__vfork, __libc_vfork) |