1 /* Thread-local storage handling in the ELF dynamic linker.
3 Copyright (C) 2011-2017 Free Software Foundation, Inc.
5 This file is part of the GNU C Library.
7 The GNU C Library is free software; you can redistribute it and/or
8 modify it under the terms of the GNU Lesser General Public
9 License as published by the Free Software Foundation; either
10 version 2.1 of the License, or (at your option) any later version.
12 The GNU C Library is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 Lesser General Public License for more details.
17 You should have received a copy of the GNU Lesser General Public
18 License along with the GNU C Library; if not, see
19 <http://www.gnu.org/licenses/>. */
25 #define NSAVEDQREGPAIRS 16
26 #define SAVE_Q_REGISTERS \
27 stp q0, q1, [sp, #-32*NSAVEDQREGPAIRS]!; \
28 cfi_adjust_cfa_offset (32*NSAVEDQREGPAIRS); \
29 stp q2, q3, [sp, #32*1]; \
30 stp q4, q5, [sp, #32*2]; \
31 stp q6, q7, [sp, #32*3]; \
32 stp q8, q9, [sp, #32*4]; \
33 stp q10, q11, [sp, #32*5]; \
34 stp q12, q13, [sp, #32*6]; \
35 stp q14, q15, [sp, #32*7]; \
36 stp q16, q17, [sp, #32*8]; \
37 stp q18, q19, [sp, #32*9]; \
38 stp q20, q21, [sp, #32*10]; \
39 stp q22, q23, [sp, #32*11]; \
40 stp q24, q25, [sp, #32*12]; \
41 stp q26, q27, [sp, #32*13]; \
42 stp q28, q29, [sp, #32*14]; \
43 stp q30, q31, [sp, #32*15];
45 #define RESTORE_Q_REGISTERS \
46 ldp q2, q3, [sp, #32*1]; \
47 ldp q4, q5, [sp, #32*2]; \
48 ldp q6, q7, [sp, #32*3]; \
49 ldp q8, q9, [sp, #32*4]; \
50 ldp q10, q11, [sp, #32*5]; \
51 ldp q12, q13, [sp, #32*6]; \
52 ldp q14, q15, [sp, #32*7]; \
53 ldp q16, q17, [sp, #32*8]; \
54 ldp q18, q19, [sp, #32*9]; \
55 ldp q20, q21, [sp, #32*10]; \
56 ldp q22, q23, [sp, #32*11]; \
57 ldp q24, q25, [sp, #32*12]; \
58 ldp q26, q27, [sp, #32*13]; \
59 ldp q28, q29, [sp, #32*14]; \
60 ldp q30, q31, [sp, #32*15]; \
61 ldp q0, q1, [sp], #32*NSAVEDQREGPAIRS; \
62 cfi_adjust_cfa_offset (-32*NSAVEDQREGPAIRS);
66 /* Compute the thread pointer offset for symbols in the static
67 TLS block. The offset is the same for all threads.
69 _dl_tlsdesc_return (tlsdesc *) ;
71 .hidden _dl_tlsdesc_return
72 .global _dl_tlsdesc_return
73 .type _dl_tlsdesc_return,%function
78 ldr PTR_REG (0), [x0, #PTR_SIZE]
81 .size _dl_tlsdesc_return, .-_dl_tlsdesc_return
83 /* Handler for undefined weak TLS symbols.
85 _dl_tlsdesc_undefweak (tlsdesc *);
87 The second word of the descriptor contains the addend.
88 Return the addend minus the thread pointer. This ensures
89 that when the caller adds on the thread pointer it gets back
92 .hidden _dl_tlsdesc_undefweak
93 .global _dl_tlsdesc_undefweak
94 .type _dl_tlsdesc_undefweak,%function
97 _dl_tlsdesc_undefweak:
99 cfi_adjust_cfa_offset (16)
101 ldr PTR_REG (0), [x0, #PTR_SIZE]
103 sub PTR_REG (0), PTR_REG (0), PTR_REG (1)
105 cfi_adjust_cfa_offset (-16)
108 .size _dl_tlsdesc_undefweak, .-_dl_tlsdesc_undefweak
111 /* Handler for dynamic TLS symbols.
113 _dl_tlsdesc_dynamic (tlsdesc *) ;
115 The second word of the descriptor points to a
116 tlsdesc_dynamic_arg structure.
118 Returns the offset between the thread pointer and the
119 object referenced by the argument.
122 __attribute__ ((__regparm__ (1)))
123 _dl_tlsdesc_dynamic (struct tlsdesc *tdp)
125 struct tlsdesc_dynamic_arg *td = tdp->arg;
126 dtv_t *dtv = *(dtv_t **)((char *)__thread_pointer + TCBHEAD_DTV);
127 if (__builtin_expect (td->gen_count <= dtv[0].counter
128 && (dtv[td->tlsinfo.ti_module].pointer.val
129 != TLS_DTV_UNALLOCATED),
131 return dtv[td->tlsinfo.ti_module].pointer.val
132 + td->tlsinfo.ti_offset
135 return ___tls_get_addr (&td->tlsinfo) - __thread_pointer;
139 .hidden _dl_tlsdesc_dynamic
140 .global _dl_tlsdesc_dynamic
141 .type _dl_tlsdesc_dynamic,%function
145 # define NSAVEXREGPAIRS 2
146 stp x29, x30, [sp,#-(32+16*NSAVEXREGPAIRS)]!
147 cfi_adjust_cfa_offset (32+16*NSAVEXREGPAIRS)
148 cfi_rel_offset (x29, 0)
149 cfi_rel_offset (x30, 8)
153 /* Save just enough registers to support fast path, if we fall
154 into slow path we will save additional registers. */
156 stp x1, x2, [sp, #32+16*0]
157 stp x3, x4, [sp, #32+16*1]
158 cfi_rel_offset (x1, 32)
159 cfi_rel_offset (x2, 32+8)
160 cfi_rel_offset (x3, 32+16)
161 cfi_rel_offset (x4, 32+24)
164 ldr PTR_REG (1), [x0,#TLSDESC_ARG]
165 ldr PTR_REG (0), [x4,#TCBHEAD_DTV]
166 ldr PTR_REG (3), [x1,#TLSDESC_GEN_COUNT]
167 ldr PTR_REG (2), [x0,#DTV_COUNTER]
168 cmp PTR_REG (3), PTR_REG (2)
170 ldr PTR_REG (2), [x1,#TLSDESC_MODID]
171 add PTR_REG (0), PTR_REG (0), PTR_REG (2), lsl #(PTR_LOG_SIZE + 1)
172 ldr PTR_REG (0), [x0] /* Load val member of DTV entry. */
173 cmp PTR_REG (0), #TLS_DTV_UNALLOCATED
175 ldr PTR_REG (1), [x1,#TLSDESC_MODOFF]
176 add PTR_REG (0), PTR_REG (0), PTR_REG (1)
177 sub PTR_REG (0), PTR_REG (0), PTR_REG (4)
179 ldp x1, x2, [sp, #32+16*0]
180 ldp x3, x4, [sp, #32+16*1]
182 ldp x29, x30, [sp], #(32+16*NSAVEXREGPAIRS)
183 cfi_adjust_cfa_offset (-32-16*NSAVEXREGPAIRS)
186 # undef NSAVEXREGPAIRS
189 /* This is the slow path. We need to call __tls_get_addr() which
190 means we need to save and restore all the register that the
191 callee will trash. */
193 /* Save the remaining registers that we must treat as caller save. */
194 # define NSAVEXREGPAIRS 7
195 stp x5, x6, [sp, #-16*NSAVEXREGPAIRS]!
196 cfi_adjust_cfa_offset (16*NSAVEXREGPAIRS)
197 stp x7, x8, [sp, #16*1]
198 stp x9, x10, [sp, #16*2]
199 stp x11, x12, [sp, #16*3]
200 stp x13, x14, [sp, #16*4]
201 stp x15, x16, [sp, #16*5]
202 stp x17, x18, [sp, #16*6]
203 cfi_rel_offset (x5, 0)
204 cfi_rel_offset (x6, 8)
205 cfi_rel_offset (x7, 16)
206 cfi_rel_offset (x8, 16+8)
207 cfi_rel_offset (x9, 16*2)
208 cfi_rel_offset (x10, 16*2+8)
209 cfi_rel_offset (x11, 16*3)
210 cfi_rel_offset (x12, 16*3+8)
211 cfi_rel_offset (x13, 16*4)
212 cfi_rel_offset (x14, 16*4+8)
213 cfi_rel_offset (x15, 16*5)
214 cfi_rel_offset (x16, 16*5+8)
215 cfi_rel_offset (x17, 16*6)
216 cfi_rel_offset (x18, 16*6+8)
224 sub PTR_REG (0), PTR_REG (0), PTR_REG (1)
228 ldp x7, x8, [sp, #16*1]
229 ldp x9, x10, [sp, #16*2]
230 ldp x11, x12, [sp, #16*3]
231 ldp x13, x14, [sp, #16*4]
232 ldp x15, x16, [sp, #16*5]
233 ldp x17, x18, [sp, #16*6]
234 ldp x5, x6, [sp], #16*NSAVEXREGPAIRS
235 cfi_adjust_cfa_offset (-16*NSAVEXREGPAIRS)
238 .size _dl_tlsdesc_dynamic, .-_dl_tlsdesc_dynamic
239 # undef NSAVEXREGPAIRS