2 * Copyright (c) 2014 The FreeBSD Foundation
5 * This software was developed by Andrew Turner under
6 * sponsorship from the FreeBSD Foundation.
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
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.
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 #include <machine/asm.h>
31 __FBSDID("$FreeBSD$");
34 mov x19, x0 /* Put ps_strings in a callee-saved register */
35 mov x20, sp /* And the stack pointer */
37 sub sp, sp, #16 /* Make room for obj_main & exit proc */
39 mov x1, sp /* exit_proc */
40 add x2, x1, #8 /* obj_main */
41 bl _rtld /* Call the loader */
42 mov x8, x0 /* Backup the entry point */
44 ldr x2, [sp] /* Load cleanup */
45 ldr x1, [sp, #8] /* Load obj_main */
46 mov x0, x19 /* Restore ps_strings */
47 mov sp, x20 /* Restore the stack pointer */
48 br x8 /* Jump to the entry point */
52 * sp + 0 = &GOT[x + 3]
55 * x17 = &_rtld_bind_start
57 ENTRY(_rtld_bind_start)
60 /* Save the arguments */
61 stp x0, x1, [sp, #-16]!
62 stp x2, x3, [sp, #-16]!
63 stp x4, x5, [sp, #-16]!
64 stp x6, x7, [sp, #-16]!
65 stp x8, xzr, [sp, #-16]!
67 /* Save any floating-point arguments */
68 stp q0, q1, [sp, #-32]!
69 stp q2, q3, [sp, #-32]!
70 stp q4, q5, [sp, #-32]!
71 stp q6, q7, [sp, #-32]!
73 /* Calculate reloff */
74 ldr x2, [x17, #0] /* Get the address of the entry */
75 sub x1, x2, x16 /* Find its offset */
76 sub x1, x1, #8 /* Adjust for x16 not being at offset 0 */
77 /* Each rela item has 3 entriesso we need reloff = 3 * index */
78 lsl x3, x1, #1 /* x3 = 2 * offset */
79 add x1, x1, x3 /* x1 = x3 + offset = 3 * offset */
87 /* Restore the registers saved by the plt code */
88 ldp xzr, x30, [sp, #(5 * 16 + 4 * 32)]
90 /* Backup the address to branch to */
93 /* restore the arguments */
98 ldp x8, xzr, [sp], #16
100 ldp x4, x5, [sp], #16
101 ldp x2, x3, [sp], #16
102 ldp x0, x1, [sp], #16
103 /* And the part of the stack the plt entry handled */
106 /* Call into the correct function */
108 END(_rtld_bind_start)
111 * uint64_t _rtld_tlsdesc(struct tlsdesc *);
126 * uint64_t _rtld_tlsdesc_dynamic(struct tlsdesc *);
128 * TODO: We could lookup the saved index here to skip saving the entire stack.
130 ENTRY(_rtld_tlsdesc_dynamic)
131 /* Store any registers we may use in rtld_tlsdesc_handle */
132 stp x29, x30, [sp, #-(10 * 16)]!
134 stp x1, x2, [sp, #(1 * 16)]
135 stp x3, x4, [sp, #(2 * 16)]
136 stp x5, x6, [sp, #(3 * 16)]
137 stp x7, x8, [sp, #(4 * 16)]
138 stp x9, x10, [sp, #(5 * 16)]
139 stp x11, x12, [sp, #(6 * 16)]
140 stp x13, x14, [sp, #(7 * 16)]
141 stp x15, x16, [sp, #(8 * 16)]
142 stp x17, x18, [sp, #(9 * 16)]
144 /* Find the tls offset */
147 bl rtld_tlsdesc_handle
149 /* Restore the registers */
150 ldp x17, x18, [sp, #(9 * 16)]
151 ldp x15, x16, [sp, #(8 * 16)]
152 ldp x13, x14, [sp, #(7 * 16)]
153 ldp x11, x12, [sp, #(6 * 16)]
154 ldp x9, x10, [sp, #(5 * 16)]
155 ldp x7, x8, [sp, #(4 * 16)]
156 ldp x5, x6, [sp, #(3 * 16)]
157 ldp x3, x4, [sp, #(2 * 16)]
158 ldp x1, x2, [sp, #(1 * 16)]
159 ldp x29, x30, [sp], #(10 * 16)
162 END(_rtld_tlsdesc_dynamic)