[thirdparty/glibc.git] / sysdeps / unix / sysv / linux / x86_64 / __start_context.S

/* Copyright (C) 2002-2014 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Andreas Jaeger <aj@suse.de>, 2002.

   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 <sysdep.h>

/* This is the helper code which gets called if a function which is
   registered with 'makecontext' returns.  In this case we have to
   install the context listed in the uc_link element of the context
   'makecontext' manipulated at the time of the 'makecontext' call.
   If the pointer is NULL the process must terminate.  */


ENTRY(__start_context)
	/* This removes the parameters passed to the function given to
	   'makecontext' from the stack.  RBX contains the address
	   on the stack pointer for the next context.  */
	movq	%rbx, %rsp

	popq	%rdi			/* This is the next context.  */
	cfi_adjust_cfa_offset(-8)
	testq	%rdi, %rdi
	je	2f			/* If it is zero exit.  */

	call	JUMPTARGET(__setcontext)
	/* If this returns (which can happen if the syscall fails) we'll
	   exit the program with the return error value (-1).  */
	movq	%rax,%rdi

2:
	call	HIDDEN_JUMPTARGET(exit)
	/* The 'exit' call should never return.  In case it does cause
	   the process to terminate.  */
	hlt
END(__start_context)
Commit	Line	Data
d4697bc9	1	/* Copyright (C) 2002-2014 Free Software Foundation, Inc.
c816e074 AJ	2	This file is part of the GNU C Library.
	3	Contributed by Andreas Jaeger <aj@suse.de>, 2002.
	4
	5	The GNU C Library is free software; you can redistribute it and/or
	6	modify it under the terms of the GNU Lesser General Public
	7	License as published by the Free Software Foundation; either
	8	version 2.1 of the License, or (at your option) any later version.
	9
	10	The GNU C Library is distributed in the hope that it will be useful,
	11	but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	13	Lesser General Public License for more details.
	14
	15	You should have received a copy of the GNU Lesser General Public
59ba27a6 PE	16	License along with the GNU C Library; if not, see
59ba27a6 PE	17	<http://www.gnu.org/licenses/>. */
c816e074 AJ	18
	19	#include <sysdep.h>
	20
	21	/* This is the helper code which gets called if a function which is
	22	registered with 'makecontext' returns. In this case we have to
	23	install the context listed in the uc_link element of the context
	24	'makecontext' manipulated at the time of the 'makecontext' call.
	25	If the pointer is NULL the process must terminate. */
	26
	27
	28	ENTRY(__start_context)
	29	/* This removes the parameters passed to the function given to
	30	'makecontext' from the stack. RBX contains the address
	31	on the stack pointer for the next context. */
	32	movq %rbx, %rsp
	33
	34	popq %rdi /* This is the next context. */
0e328c85	35	cfi_adjust_cfa_offset(-8)
c816e074 AJ	36	testq %rdi, %rdi
	37	je 2f /* If it is zero exit. */
	38
	39	call JUMPTARGET(__setcontext)
	40	/* If this returns (which can happen if the syscall fails) we'll
	41	exit the program with the return error value (-1). */
f7db3170	42	movq %rax,%rdi
c816e074	43
f7db3170	44	2:
ea493b56	45	call HIDDEN_JUMPTARGET(exit)
c816e074 AJ	46	/* The 'exit' call should never return. In case it does cause
	47	the process to terminate. */
	48	hlt
	49	END(__start_context)