ldasm.S revision 1.42 
1/*	$OpenBSD: ldasm.S,v 1.42 2016/03/21 22:41:29 bluhm Exp $	*/
2/*	$NetBSD: rtld_start.S,v 1.5 2001/08/14 22:17:48 eeh Exp $	*/
3
4/*
5 * Copyright (c) 2001 Jason L. Wright (jason@thought.net)
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
19 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
20 * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
21 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
22 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
23 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
25 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
26 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
27 * POSSIBILITY OF SUCH DAMAGE.
28 */
29
30/*-
31 * Copyright (c) 2000 Eduardo Horvath.
32 * Copyright (c) 1999 The NetBSD Foundation, Inc.
33 * All rights reserved.
34 *
35 * This code is derived from software contributed to The NetBSD Foundation
36 * by Christos Zoulas and Paul Kranenburg.
37 *
38 * Redistribution and use in source and binary forms, with or without
39 * modification, are permitted provided that the following conditions
40 * are met:
41 * 1. Redistributions of source code must retain the above copyright
42 *    notice, this list of conditions and the following disclaimer.
43 * 2. Redistributions in binary form must reproduce the above copyright
44 *    notice, this list of conditions and the following disclaimer in the
45 *    documentation and/or other materials provided with the distribution.
46 * 3. All advertising materials mentioning features or use of this software
47 *    must display the following acknowledgement:
48 *	This product includes software developed by the NetBSD
49 *	Foundation, Inc. and its contributors.
50 * 4. Neither the name of The NetBSD Foundation nor the names of its
51 *    contributors may be used to endorse or promote products derived
52 *    from this software without specific prior written permission.
53 *
54 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
55 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
56 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
57 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
58 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
59 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
60 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
61 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
62 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
63 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
64 * POSSIBILITY OF SUCH DAMAGE.
65 */
66
67#include <sys/syscall.h>
68#include <machine/trap.h>
69#include <machine/asm.h>
70#define	_LOCORE
71#include <machine/frame.h>
72
73/*
74 * ELF:
75 *	On startup the stack should contain 16 extended word register save
76 *	area, followed by the arg count, etc.
77 *
78 * _rtld() expects the stack pointer to point to two longwords for argument
79 *	return followed by argc, etc.  We need to create a pointer to
80 *	&argc + 16 and pass that in.  The return args will be in those
81 *	locations.
82 */
83
84/* Offset of ARGC from bottom of stack */
85#define	ARGC	CC64FSZ
86/* XXX - DL_DATA_SIZE should be (9*8), but I can't think right now. */
87#define DL_DATA_SIZE (16*8)
88
89	.section	".text"
90	.align	16
91	.register %g2,#scratch
92
93_ENTRY(_dl_start)
94	sub	%g0, %g0, %fp		! clear frame
95	sub	%sp, 48 + DL_DATA_SIZE, %sp	! make room for dl_data
96	add	%sp, BIAS + ARGC, %l3
97
98	add	%l3, DL_DATA_SIZE, %o0
99	mov	%o0, %l0
100
101	/*
102	 * need to figure out where _DYNAMIC is located, newer binutils
103	 * does not fill in GOT to read _DYNAMIC before relocation.
104	 */
105	call	0f
106	 nop
107	call	_DYNAMIC+8		! not executed (no delay needed)
1080:	ld	[%o7+8], %o2		! load stub call instruction
109	sll	%o2, 2, %o2		! extract PC offset
110	sra	%o2, 0, %o2		! sign-extend
111
112	add	%o2, %o7, %o2		! real &_DYNAMIC
113
114	call	_dl_boot_bind		! _dl_boot_bind(sp,dl_data,dynamicp)
115	 mov	%l3, %o1
116
117	mov	%l3, %o3
118	ldx	[%l0], %l3		! argc = *sp
119	sllx	%l3, 3, %l3		! argc *= sizeof(long)
120	addx	%l0, 8, %o0		! argv = [sp + argc]
121	addx	%l0, 16, %o1		! envp = sp + 16 +
122	addx	%o1, %l3, %o1		!	+ argc
123
124	addx	%o3, (7*8), %l2
125	ldx	[%l2], %o2		! loff = dl_data[AUX_base];
126
127	call	_dl_boot		! _dl_boot(argv,envp,loff,dl_data)
128	 nop
129
130	add	%sp, 48 + DL_DATA_SIZE, %sp	! restore stack
131
1321:	call	2f
133	 sethi	%hi(_GLOBAL_OFFSET_TABLE_+(.-1b)), %l7
1342:	or	%l7, %lo(_GLOBAL_OFFSET_TABLE_+(.-1b)), %l7
135	add	%l7, %o7, %l7
136
137	jmp	%o0
138	 ldx	[%l7 + _dl_dtors], %g1	! %g1 = cleanup
139
140	/*
141	 * We have two separate entry points to the runtime linker.
142	 * I'm implementing this following the SPARC v9 ABI spec.
143	 *
144	 * _dl_bind_start_0(x, y) is called from .PLT0, and is used for
145	 * PLT entries above 32768.
146	 *
147	 * _dl_bind_start_1(x, y) is called from .PLT1, and is used for
148	 * PLT entries below 32768.
149	 *
150	 * The first two entries of PLT2 contain the xword object pointer.
151	 *
152	 * These routines are called with two longword arguments,
153	 * x and y.  To calculate the address of the entry,
154	 * _dl_bind_start_1(x, y) does:
155	 *
156	 *	n = x >> 15;
157	 *
158	 * and _dl_bind_start_0(x, y) does:
159	 *
160	 *	i = x - y + 8 - 32768*32;
161	 *	n = 32768 + (i/5120)*160 + (i%5120)/24;
162	 *
163	 * Neither routine needs to issue a save since it's already been
164	 * done in the PLT entry.
165	 */
166
167	/* NOTE: _dl_bind_start_0 is untested.  Hence the debug stuff */
168
169_ENTRY(_dl_bind_start_0)		# (x, y)
170	sethi	%hi(32768*32-8), %l1
171	sub	%o0, %o1, %l0		/* x - y */
172	or	%l1, %lo(32768*32-8), %l1
173	sub	%l0, %l1, %l0		/* x - y + 8 - 32768*32 */
174
175	sethi	%hi(5120), %l1
176	sdivx	%l0, %l1, %l1		/* Calculate i/5120 */
177	ldx	[%o1 + (10*4)], %o0	/* Load object pointer from PLT2 */
178	sllx	%l1, 2, %l2
179	add	%l1, %l2, %l2
180	sllx	%l2, 10, %l2
181	sub	%l0, %l2, %l2		/* And i%5120 */
182
183	/* Let the division churn for a bit. */
184	sdivx	%l2, 24, %l4		/* (i%5120)/24 */
185
186	/* 160 is (32 * 5) or (32 * (4 + 1)) */
187	sllx	%l1, 2, %l3		/* 4 * (i/5120) */
188	add	%l1, %l3, %l3		/* 5 * (i/5120) */
189	sllx	%l3, 5, %l3		/* 32 * 5 * (i/5120) */
190
191	sethi	%hi(32768), %l6
192	add	%l3, %l4, %l5		/* %l5 = (i/5120)*160 + (i%5120)/24; */
193	add	%l5, %l6, %l5
194
195	call	_dl_bind		/* Call _dl_bind(obj, offset) */
196	 mov	%l5, %o1
197
198	jmp	%o0			/* return value == function address */
199	 restore			/* Dump our stack frame */
200
201_ENTRY(_dl_bind_start_1)		# (x, y)
202	srax	%o0, 15, %o2		/* %o0 is the index to our PLT slot */
203
204	ldx	[%o1 + 8], %o0		/* The object pointer is at [%o1 + 8] */
205
206	call	_dl_bind		/* Call _dl_bind(obj, offset) */
207	 mov	%o2, %o1
208
209	jmp	%o0			/* return value == function address */
210	 restore			/* Dump our stack frame */
211
212_ENTRY(_dl_close)
213	mov SYS_close | SYSCALL_G2RFLAG, %g1	! call sys_close
214	add %o7, 8, %g2				! just return on success
215	t ST_SYSCALL				! off to wonderland
216	retl
217	 sub %g0, %o0, %o0			! error: result = -errno
218
219_ENTRY(_dl_exit)
220	mov SYS_exit | SYSCALL_G2RFLAG, %g1	! call sys_exit
221	add %o7, 8, %g2				! just return on success
222	t ST_SYSCALL				! off to wonderland
223	retl
224	 sub %g0, %o0, %o0			! error: result = -errno
225
226_ENTRY(_dl_issetugid)
227	mov SYS_issetugid | SYSCALL_G2RFLAG, %g1	! call sys_issetugid
228	add %o7, 8, %g2					! just return on success
229	t ST_SYSCALL					! off to wonderland
230	retl
231	 sub %g0, %o0, %o0				! error: result = -errno
232
233_ENTRY(_dl__syscall)
234	mov SYS___syscall | SYSCALL_G2RFLAG, %g1	! call sys___syscall
235	add %o7, 8, %g2				! just return on success
236	t ST_SYSCALL				! off to wonderland
237	retl
238	 sub %g0, %o0, %o0			! error: result = -errno
239
240_ENTRY(_dl_munmap)
241	mov SYS_munmap | SYSCALL_G2RFLAG, %g1	! calling sys_munmap
242	add %o7, 8, %g2				! just return on success
243	t ST_SYSCALL				! off to wonderland
244	retl
245	 sub %g0, %o0, %o0			! error: result = -errno
246
247_ENTRY(_dl_mprotect)
248	mov SYS_mprotect | SYSCALL_G2RFLAG, %g1	! calling sys_mprotect
249	add %o7, 8, %g2				! just return on success
250	t ST_SYSCALL				! off to wonderland
251	retl
252	 sub %g0, %o0, %o0			! error: result = -errno
253
254_ENTRY(_dl_open)
255	mov SYS_open | SYSCALL_G2RFLAG, %g1	! calling sys_open
256	add %o7, 8, %g2				! just return on success
257	t ST_SYSCALL				! off to wonderland
258	retl
259	 sub %g0, %o0, %o0			! error: result = -errno
260
261_ENTRY(_dl_read)
262	mov SYS_read | SYSCALL_G2RFLAG, %g1	! calling sys_read
263	add %o7, 8, %g2				! just return on success
264	t ST_SYSCALL				! off to wonderland
265	retl
266	 sub %g0, %o0, %o0			! error: result = -errno
267
268_ENTRY(_dl_write)
269	mov SYS_write | SYSCALL_G2RFLAG, %g1	! calling sys_write
270	add %o7, 8, %g2				! just return on success
271	t ST_SYSCALL				! off to wonderland
272	retl
273	 sub %g0, %o0, %o0			! error: result = -errno
274
275_ENTRY(_dl_fstat)
276	mov  SYS_fstat | SYSCALL_G2RFLAG, %g1	! call sys_fstat
277	add %o7, 8, %g2				! just return on success
278	t ST_SYSCALL				! off to wonderland
279	retl
280	 sub %g0, %o0, %o0			! error: result = -errno
281
282_ENTRY(_dl_getdents)
283	mov  SYS_getdents | SYSCALL_G2RFLAG, %g1	! call sys_getdents
284	add %o7, 8, %g2					! just return on success
285	t ST_SYSCALL					! off to wonderland
286	retl
287	 sub %g0, %o0, %o0				! error: result = -errno
288
289_ENTRY(_dl_sysctl)
290	mov  SYS_sysctl | SYSCALL_G2RFLAG, %g1		! call sys_sysctl
291	add %o7, 8, %g2					! just return on success
292	t ST_SYSCALL					! off to wonderland
293	retl
294	 sub %g0, %o0, %o0				! error: result = -errno
295
296_ENTRY(_dl_gettimeofday)
297	mov SYS_gettimeofday | SYSCALL_G2RFLAG, %g1	! calling sys_gettimeofday
298	add %o7, 8, %g2				! just return on success
299	t ST_SYSCALL				! off to wonderland
300	retl
301	 sub %g0, %o0, %o0			! error: result = -errno
302
303_ENTRY(_dl_readlink)
304	mov SYS_readlink | SYSCALL_G2RFLAG, %g1	! calling sys_readlink
305	add %o7, 8, %g2				! just return on success
306	t ST_SYSCALL				! off to wonderland
307	retl
308	 sub %g0, %o0, %o0			! error: result = -errno
309
310_ENTRY(_dl_lstat)
311	mov SYS_lstat | SYSCALL_G2RFLAG, %g1	! calling sys_lstat
312	add %o7, 8, %g2				! just return on success
313	t ST_SYSCALL				! off to wonderland
314	retl
315	 sub %g0, %o0, %o0			! error: result = -errno
316
317_ENTRY(_dl_getcwd)
318	mov SYS___getcwd | SYSCALL_G2RFLAG, %g1	! calling sys___getcwd
319	add %o7, 8, %g2				! just return on success
320	t ST_SYSCALL				! off to wonderland
321	retl
322	 sub %g0, %o0, %o0			! error: result = -errno
323
324_ENTRY(_dl_utrace)
325	mov SYS_utrace | SYSCALL_G2RFLAG, %g1	! calling sys_utrace
326	add %o7, 8, %g2				! just return on success
327	t ST_SYSCALL				! off to wonderland
328	retl
329	 sub %g0, %o0, %o0			! error: result = -errno
330
331_ENTRY(_dl_getentropy)
332	mov SYS_getentropy | SYSCALL_G2RFLAG, %g1	! calling sys_getentropy
333	add %o7, 8, %g2				! just return on success
334	t ST_SYSCALL				! off to wonderland
335	retl
336	 sub %g0, %o0, %o0			! error: result = -errno
337
338_ENTRY(_dl_sendsyslog)
339	mov SYS_sendsyslog | SYSCALL_G2RFLAG, %g1	! calling sys_sendsyslog
340	add %o7, 8, %g2				! just return on success
341	t ST_SYSCALL				! off to wonderland
342	retl
343	 sub %g0, %o0, %o0			! error: result = -errno
344
345_ENTRY(_dl_pledge)
346	mov SYS_pledge | SYSCALL_G2RFLAG, %g1	! calling sys_pledge
347	add %o7, 8, %g2				! just return on success
348	t ST_SYSCALL				! off to wonderland
349	retl
350	 sub %g0, %o0, %o0			! error: result = -errno
351