1 /* PLT trampolines. hppa version.
2 Copyright (C) 2005-2023 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
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.
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.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library. If not, see
17 <https://www.gnu.org/licenses/>. */
21 /* This code gets called via the .plt stub, and is used in
22 dl-runtime.c to call the `_dl_fixup' function and then redirect
23 to the address it returns. `_dl_fixup' takes two arguments, however
24 `_dl_profile_fixup' takes a number of parameters for use with
25 library auditing (LA).
27 WARNING: This template is also used by gcc's __cffc, and expects
28 that the "bl" for _dl_runtime_resolve exist at a particular offset.
29 Do not change this template without changing gcc, while the prefix
30 "bl" should fix everything so gcc finds the right spot, it will
31 slow down __cffc when it attempts to call fixup to resolve function
32 descriptor references. Please refer to gcc/gcc/config/pa/fptr.c
34 Enter with r19 = reloc offset, r20 = got-8, r21 = fixup ltp, r22 = fp. */
36 /* RELOCATION MARKER: bl to provide gcc's __cffc with fixup loc. */
38 /* THIS CODE DOES NOT EXECUTE */
41 .global _dl_runtime_resolve
42 .type _dl_runtime_resolve,@function
47 .CALLINFO FRAME=128,CALLS,SAVE_RP,ENTRY_GR=3
49 /* SAVE_RP says we do */
52 /* Save static link register */
54 /* Save argument registers */
60 /* Build a call frame, and save structure pointer. */
61 copy %sp, %r1 /* Copy previous sp */
62 /* Save function result address (on entry) */
64 /* Fill in some frame info to follow ABI */
65 stw %r1,-4(%sp) /* Previous sp */
66 stw %r21,-32(%sp) /* PIC register value */
68 /* Save input floating point registers. This must be done
69 in the new frame since the previous frame doesn't have
76 /* Test PA_GP_RELOC bit. */
77 bb,>= %r19,31,2f /* branch if not reloc offset */
80 /* Set up args to fixup func, needs only two arguments */
81 ldw 8+4(%r20),%r26 /* (1) got[1] == struct link_map */
82 copy %r19,%r25 /* (2) reloc offset */
84 /* Call the real address resolver. */
86 copy %r21,%r19 /* set fixup func ltp */
88 /* While the linker will set a function pointer to NULL when it
89 encounters an undefined weak function, we need to dynamically
90 detect removed weak functions. The issue arises because a weak
91 __gmon_start__ function was added to shared executables to work
92 around issues in _init that are now resolved. The presence of
93 __gmon_start__ in every shared library breaks the linker
94 `--as-needed' option. This __gmon_start__ function does nothing
95 but removal is tricky. Depending on the binding, removal can
96 cause an application using it to fault. The call to _dl_fixup
97 returns NULL when a function isn't resolved. In order to help
98 with __gmon_start__ removal, we return directly to the caller
99 when _dl_fixup returns NULL. This check could be removed when
100 BZ 19170 is fixed. */
103 /* Load up the returned func descriptor */
107 /* Reload arguments fp args */
114 /* Adjust sp, and restore function result address*/
117 /* Reload static link register */
119 /* Reload general args */
125 /* Jump to new function, but return to previous function */
130 /* Return to previous function */
136 /* Set up args for _dl_fix_reloc_arg. */
137 copy %r22,%r26 /* (1) function pointer */
138 depi 0,31,2,%r26 /* clear least significant bits */
139 ldw 8+4(%r20),%r25 /* (2) got[1] == struct link_map */
141 /* Save ltp and link map arg for _dl_fixup. */
142 stw %r21,-56(%sp) /* ltp */
143 stw %r25,-60(%sp) /* struct link map */
145 /* Find reloc offset. */
146 bl _dl_fix_reloc_arg,%rp
147 copy %r21,%r19 /* set func ltp */
149 /* Set up args for _dl_fixup. */
150 ldw -56(%sp),%r21 /* ltp */
151 ldw -60(%sp),%r26 /* (1) struct link map */
153 copy %ret0,%r25 /* (2) reloc offset */
157 .size _dl_runtime_resolve, . - _dl_runtime_resolve
160 .global _dl_runtime_profile
161 .type _dl_runtime_profile,@function
166 .CALLINFO FRAME=192,CALLS,SAVE_RP,ENTRY_GR=3
169 /* SAVE_RP says we do */
171 /* Save static link register */
174 /* Build a call frame, and save structure pointer. */
175 copy %sp, %r1 /* Copy previous sp */
176 /* Save function result address (on entry) */
178 /* Fill in some frame info to follow ABI */
179 stw %r1,-4(%sp) /* Previous sp */
180 stw %r21,-32(%sp) /* PIC register value */
182 /* Create La_hppa_retval */
186 -128, lr_fr4 (8 bytes) */
188 /* Create save space for _dl_profile_fixup arguments
189 -120, Saved reloc offset
190 -116, Saved struct link_map
193 /* Create La_hppa_regs */
194 /* 32-bit registers */
199 /* -92, 4 byte pad */
200 /* 64-bit floating point registers */
207 /* Test PA_GP_RELOC bit. */
208 bb,>= %r19,31,2f /* branch if not reloc offset */
209 /* 32-bit stack pointer */
212 /* Set up args to fixup func, needs five arguments */
213 ldw 8+4(%r20),%r26 /* (1) got[1] == struct link_map */
214 stw %r26,-116(%sp) /* Save struct link_map */
215 copy %r19,%r25 /* (2) reloc offset */
216 stw %r25,-120(%sp) /* Save reloc offset */
217 copy %rp,%r24 /* (3) profile_fixup needs rp */
218 ldo -56(%sp),%r23 /* (4) La_hppa_regs */
220 stw %r1, -52(%sp) /* (5) long int *framesizep */
222 /* Call the real address resolver. */
223 3: bl _dl_profile_fixup,%rp
224 copy %r21,%r19 /* set fixup func ltp */
226 /* Load up the returned function descriptor */
230 /* Restore gr/fr/sp/rp */
235 /* -92, 4 byte pad, skip */
242 /* Reload rp register -(192+20) without adjusting stack */
245 /* Reload static link register -(192+16) without adjusting stack */
248 /* *framesizep is >= 0 if we have to run pltexit */
250 cmpb,>>=,N %r0,%r28,L(cpe)
252 /* Adjust sp, and restore function result address*/
254 /* Jump to new function, but return to previous function */
260 /* Call the returned function descriptor */
266 /* We are going to call the resolved function, but we have a
267 stack frame in the middle. We use the value of framesize to
268 guess how much extra frame we need, and how much frame to
271 /* Round to nearest multiple of 64 */
275 /* Calculate start of stack copy */
278 /* Increate the stack by *framesizep */
281 /* Save stack pointer */
284 /* Single byte copy of previous stack onto newly allocated stack */
285 1: ldb %r28(%r2), %r1
291 /* Restore r28 and r27 and r2 already points at -192(%sp) */
295 /* Calculate address of L(cont) */
299 /* Undo fake stack */
303 /* Arguments to _dl_audit_pltexit */
304 ldw -116(%sp), %r26 /* (1) got[1] == struct link_map */
305 ldw -120(%sp), %r25 /* (2) reloc offsets */
306 ldo -56(%sp), %r24 /* (3) *La_hppa_regs */
307 ldo -124(%sp), %r23 /* (4) *La_hppa_retval */
309 /* Fill *La_hppa_retval */
315 /* Call _dl_audit_pltexit */
316 bl _dl_audit_pltexit,%rp
319 /* Restore *La_hppa_retval */
325 /* Unwind the stack */
327 /* Restore callers rp */
333 /* Set up args for _dl_fix_reloc_arg. */
334 copy %r22,%r26 /* (1) function pointer */
335 depi 0,31,2,%r26 /* clear least significant bits */
336 ldw 8+4(%r20),%r25 /* (2) got[1] == struct link_map */
338 /* Save ltp and link map arg for _dl_fixup. */
339 stw %r21,-92(%sp) /* ltp */
340 stw %r25,-116(%sp) /* struct link map */
342 /* Find reloc offset. */
343 bl _dl_fix_reloc_arg,%rp
344 copy %r21,%r19 /* set func ltp */
346 /* Restore fixup ltp. */
347 ldw -92(%sp),%r21 /* ltp */
349 /* Set up args to fixup func, needs five arguments */
350 ldw -116(%sp),%r26 /* (1) struct link map */
351 copy %ret0,%r25 /* (2) reloc offset */
352 stw %r25,-120(%sp) /* Save reloc offset */
353 ldw -212(%sp),%r24 /* (3) profile_fixup needs rp */
354 ldo -56(%sp),%r23 /* (4) La_hppa_regs */
357 stw %r1, -52(%sp) /* (5) long int *framesizep */
361 .size _dl_runtime_profile, . - _dl_runtime_profile