diff options
Diffstat (limited to 'sysdeps/unix/sysv/linux/arch-fork.h')
| -rw-r--r-- | sysdeps/unix/sysv/linux/arch-fork.h | 43 |
1 files changed, 34 insertions, 9 deletions
diff --git a/sysdeps/unix/sysv/linux/arch-fork.h b/sysdeps/unix/sysv/linux/arch-fork.h index d5f542924f..3daa9651e5 100644 --- a/sysdeps/unix/sysv/linux/arch-fork.h +++ b/sysdeps/unix/sysv/linux/arch-fork.h @@ -1,4 +1,4 @@ -/* ARCH_FORK definition for Linux fork implementation. Stub version. +/* arch_fork definition for Linux fork implementation. Copyright (C) 2014-2018 Free Software Foundation, Inc. This file is part of the GNU C Library. @@ -16,12 +16,37 @@ License along with the GNU C Library; if not, see <http://www.gnu.org/licenses/>. */ -/* This file should define the function-like macro of no arguments - ARCH_FORK to an INLINE_SYSCALL invocation of the clone-like system - call, passing the CLONE_CHILD_SETTID and CLONE_CHILD_CLEARTID flags - and &THREAD_SELF->tid as the TID address. +#ifndef __ARCH_FORK_H +#define __ARCH_FORK_H - Machines that lack an arch-fork.h header file will hit an #error in - fork.c; this stub file doesn't contain an #error itself mainly for - the transition period of migrating old machine-specific fork.c files - to machine-specific arch-fork.h instead. */ +#include <unistd.h> + +/* Call the clone syscall with fork semantic. The CTID address is used + to store the child thread ID at its locationm, to erase it in child memory + when the child exits, and do a wakeup on the futex at that address. + + The architecture with non-default kernel abi semantic should correctlly + override it with one of the supported calling convention (check generic + kernel-features.h for the clone abi variants). */ +static inline pid_t +arch_fork (void *ctid) +{ + const int flags = CLONE_CHILD_SETTID | CLONE_CHILD_CLEARTID | SIGCHLD; + long int ret; +#ifdef __ASSUME_CLONE_BACKWARDS + ret = INLINE_SYSCALL_CALL (clone, flags, 0, NULL, 0, ctid); +#elif defined(__ASSUME_CLONE_BACKWARDS2) + ret = INLINE_SYSCALL_CALL (clone, 0, flags, NULL, ctid, 0); +#elif defined(__ASSUME_CLONE_BACKWARDS3) + ret = INLINE_SYSCALL_CALL (clone, flags, 0, 0, NULL, ctid, 0); +#elif defined(__ASSUME_CLONE2) + ret = INLINE_SYSCALL_CALL (clone2, flags, 0, 0, NULL, ctid, 0); +#elif defined(__ASSUME_CLONE_DEFAULT) + ret = INLINE_SYSCALL_CALL (clone, flags, 0, NULL, ctid, 0); +#else +# error "Undefined clone variant" +#endif + return ret; +} + +#endif /* __ARCH_FORK_H */ |