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-rw-r--r--libc/sysdeps/linux/x86_64/clone.S116
-rw-r--r--libc/sysdeps/linux/x86_64/vfork.S53
2 files changed, 169 insertions, 0 deletions
diff --git a/libc/sysdeps/linux/x86_64/clone.S b/libc/sysdeps/linux/x86_64/clone.S
new file mode 100644
index 000000000..9d244d018
--- /dev/null
+++ b/libc/sysdeps/linux/x86_64/clone.S
@@ -0,0 +1,116 @@
+/* Copyright (C) 2001, 2002, 2003, 2004 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, write to the Free
+ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ 02111-1307 USA. */
+
+/* clone() is even more special than fork() as it mucks with stacks
+ and invokes a function in the right context after its all over. */
+
+#define _ERRNO_H 1
+#include <bits/errno.h>
+
+#define CLONE_VM 0x00000100
+#define CLONE_THREAD 0x00010000
+
+/* The userland implementation is:
+ int clone (int (*fn)(void *arg), void *child_stack, int flags, void *arg),
+ the kernel entry is:
+ int clone (long flags, void *child_stack).
+
+ The parameters are passed in register and on the stack from userland:
+ rdi: fn
+ rsi: child_stack
+ rdx: flags
+ rcx: arg
+ r8d: TID field in parent
+ r9d: thread pointer
+%esp+8: TID field in child
+
+ The kernel expects:
+ rax: system call number
+ rdi: flags
+ rsi: child_stack
+ rdx: TID field in parent
+ r10: TID field in child
+ r8: thread pointer */
+
+
+ .text
+.globl __clone;
+.type __clone,@function
+.align 4;
+__clone:
+ /* Sanity check arguments. */
+ movq $-EINVAL,%rax
+ testq %rdi,%rdi /* no NULL function pointers */
+ jz __syscall_error
+ testq %rsi,%rsi /* no NULL stack pointers */
+ jz __syscall_error
+
+ /* Insert the argument onto the new stack. */
+ subq $16,%rsi
+ movq %rcx,8(%rsi)
+
+ /* Save the function pointer. It will be popped off in the
+ child in the ebx frobbing below. */
+ movq %rdi,0(%rsi)
+
+ /* Do the system call. */
+ movq %rdx, %rdi
+ movq %r8, %rdx
+ movq %r9, %r8
+ movq 8(%rsp), %r10
+ movq $__NR_clone,%rax
+
+ syscall
+
+ testq %rax,%rax
+ jl __syscall_error
+ jz L(thread_start)
+
+L(pseudo_end):
+ ret
+
+L(thread_start):
+ /* Clear the frame pointer. The ABI suggests this be done, to mark
+ the outermost frame obviously. */
+ xorq %rbp, %rbp
+
+#ifdef RESET_PID
+ testq $CLONE_THREAD, %rdi
+ jne 1f
+ testq $CLONE_VM, %rdi
+ movl $-1, %eax
+ jne 2f
+ movq __NR_getpid, %rax
+ syscall
+2: movl %eax, %fs:PID
+ movl %eax, %fs:TID
+1:
+#endif
+
+ /* Set up arguments for the function call. */
+ popq %rax /* Function to call. */
+ popq %rdi /* Argument. */
+ call *%rax
+ /* Call exit with return value from function call. */
+ movq %rax, %rdi
+ call HIDDEN_JUMPTARGET (_exit)
+
+ cfi_startproc;
+PSEUDO_END (BP_SYM (__clone))
+
+weak_alias (BP_SYM (__clone), BP_SYM (clone))
diff --git a/libc/sysdeps/linux/x86_64/vfork.S b/libc/sysdeps/linux/x86_64/vfork.S
new file mode 100644
index 000000000..072a3a0a8
--- /dev/null
+++ b/libc/sysdeps/linux/x86_64/vfork.S
@@ -0,0 +1,53 @@
+/* Copyright (C) 2001, 2002, 2004 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, write to the Free
+ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ 02111-1307 USA. */
+
+#define _ERRNO_H 1
+#include <bits/errno.h>
+
+/* Clone the calling process, but without copying the whole address space.
+ The calling process is suspended until the new process exits or is
+ replaced by a call to `execve'. Return -1 for errors, 0 to the new process,
+ and the process ID of the new process to the old process. */
+
+.globl __vfork;
+.type __vfork,@function;
+.align 16;
+__vfork:
+
+ /* Pop the return PC value into RDI. We need a register that
+ is preserved by the syscall and that we're allowed to destroy. */
+ popq %rdi
+
+ /* Stuff the syscall number in RAX and enter into the kernel. */
+ movl $__NR_vfork, %eax
+ syscall
+
+ /* Push back the return PC. */
+ pushq %rdi
+
+ cmpl $-4095, %eax
+ jae __syscall_error /* Branch forward if it failed. */
+
+ /* Normal return. */
+ ret
+
+__syscall_error:
+ /* TODO: implement this ! :D */
+
+.size __vfork,.Lsize-__vfork
+.weak vfork ; vfork = __vfork