elf32_machdep.c revision 330897 
1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright 1996-1998 John D. Polstra.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 *
27 * $FreeBSD: stable/11/sys/powerpc/powerpc/elf32_machdep.c 330897 2018-03-14 03:19:51Z eadler $
28 */
29
30#include <sys/param.h>
31#include <sys/kernel.h>
32#include <sys/systm.h>
33
34#define __ELF_WORD_SIZE 32
35
36#include <sys/exec.h>
37#include <sys/imgact.h>
38#include <sys/malloc.h>
39#include <sys/proc.h>
40#include <sys/namei.h>
41#include <sys/fcntl.h>
42#include <sys/sysent.h>
43#include <sys/imgact_elf.h>
44#include <sys/syscall.h>
45#include <sys/signalvar.h>
46#include <sys/vnode.h>
47#include <sys/linker.h>
48
49#include <vm/vm.h>
50#include <vm/vm_param.h>
51
52#include <machine/altivec.h>
53#include <machine/cpu.h>
54#include <machine/elf.h>
55#include <machine/reg.h>
56#include <machine/md_var.h>
57
58#ifdef __powerpc64__
59#include <compat/freebsd32/freebsd32_proto.h>
60#include <compat/freebsd32/freebsd32_util.h>
61
62extern const char *freebsd32_syscallnames[];
63#endif
64
65struct sysentvec elf32_freebsd_sysvec = {
66	.sv_size	= SYS_MAXSYSCALL,
67#ifdef __powerpc64__
68	.sv_table	= freebsd32_sysent,
69#else
70	.sv_table	= sysent,
71#endif
72	.sv_mask	= 0,
73	.sv_errsize	= 0,
74	.sv_errtbl	= NULL,
75	.sv_transtrap	= NULL,
76	.sv_fixup	= __elfN(freebsd_fixup),
77	.sv_sendsig	= sendsig,
78	.sv_sigcode	= sigcode32,
79	.sv_szsigcode	= &szsigcode32,
80	.sv_name	= "FreeBSD ELF32",
81	.sv_coredump	= __elfN(coredump),
82	.sv_imgact_try	= NULL,
83	.sv_minsigstksz	= MINSIGSTKSZ,
84	.sv_pagesize	= PAGE_SIZE,
85	.sv_minuser	= VM_MIN_ADDRESS,
86	.sv_stackprot	= VM_PROT_ALL,
87#ifdef __powerpc64__
88	.sv_maxuser	= VM_MAXUSER_ADDRESS,
89	.sv_usrstack	= FREEBSD32_USRSTACK,
90	.sv_psstrings	= FREEBSD32_PS_STRINGS,
91	.sv_copyout_strings = freebsd32_copyout_strings,
92	.sv_setregs	= ppc32_setregs,
93	.sv_syscallnames = freebsd32_syscallnames,
94#else
95	.sv_maxuser	= VM_MAXUSER_ADDRESS,
96	.sv_usrstack	= USRSTACK,
97	.sv_psstrings	= PS_STRINGS,
98	.sv_copyout_strings = exec_copyout_strings,
99	.sv_setregs	= exec_setregs,
100	.sv_syscallnames = syscallnames,
101#endif
102	.sv_fixlimit	= NULL,
103	.sv_maxssiz	= NULL,
104	.sv_flags	= SV_ABI_FREEBSD | SV_ILP32 | SV_SHP,
105	.sv_set_syscall_retval = cpu_set_syscall_retval,
106	.sv_fetch_syscall_args = cpu_fetch_syscall_args,
107	.sv_shared_page_base = FREEBSD32_SHAREDPAGE,
108	.sv_shared_page_len = PAGE_SIZE,
109	.sv_schedtail	= NULL,
110	.sv_thread_detach = NULL,
111	.sv_trap	= NULL,
112};
113INIT_SYSENTVEC(elf32_sysvec, &elf32_freebsd_sysvec);
114
115static Elf32_Brandinfo freebsd_brand_info = {
116	.brand		= ELFOSABI_FREEBSD,
117	.machine	= EM_PPC,
118	.compat_3_brand	= "FreeBSD",
119	.emul_path	= NULL,
120	.interp_path	= "/libexec/ld-elf.so.1",
121	.sysvec		= &elf32_freebsd_sysvec,
122#ifdef __powerpc64__
123	.interp_newpath	= "/libexec/ld-elf32.so.1",
124#else
125	.interp_newpath	= NULL,
126#endif
127	.brand_note	= &elf32_freebsd_brandnote,
128	.flags		= BI_CAN_EXEC_DYN | BI_BRAND_NOTE
129};
130
131SYSINIT(elf32, SI_SUB_EXEC, SI_ORDER_FIRST,
132    (sysinit_cfunc_t) elf32_insert_brand_entry,
133    &freebsd_brand_info);
134
135static Elf32_Brandinfo freebsd_brand_oinfo = {
136	.brand		= ELFOSABI_FREEBSD,
137	.machine	= EM_PPC,
138	.compat_3_brand	= "FreeBSD",
139	.emul_path	= NULL,
140	.interp_path	= "/usr/libexec/ld-elf.so.1",
141	.sysvec		= &elf32_freebsd_sysvec,
142	.interp_newpath	= NULL,
143	.brand_note	= &elf32_freebsd_brandnote,
144	.flags		= BI_CAN_EXEC_DYN | BI_BRAND_NOTE
145};
146
147SYSINIT(oelf32, SI_SUB_EXEC, SI_ORDER_ANY,
148	(sysinit_cfunc_t) elf32_insert_brand_entry,
149	&freebsd_brand_oinfo);
150
151void elf_reloc_self(Elf_Dyn *dynp, Elf_Addr relocbase);
152
153void
154elf32_dump_thread(struct thread *td, void *dst, size_t *off)
155{
156	size_t len;
157	struct pcb *pcb;
158
159	len = 0;
160	pcb = td->td_pcb;
161	if (pcb->pcb_flags & PCB_VEC) {
162		save_vec_nodrop(td);
163		if (dst != NULL) {
164			len += elf32_populate_note(NT_PPC_VMX,
165			    &pcb->pcb_vec, dst,
166			    sizeof(pcb->pcb_vec), NULL);
167		} else
168			len += elf32_populate_note(NT_PPC_VMX, NULL, NULL,
169			    sizeof(pcb->pcb_vec), NULL);
170	}
171	*off = len;
172}
173
174#ifndef __powerpc64__
175/* Process one elf relocation with addend. */
176static int
177elf_reloc_internal(linker_file_t lf, Elf_Addr relocbase, const void *data,
178    int type, int local, elf_lookup_fn lookup)
179{
180	Elf_Addr *where;
181	Elf_Half *hwhere;
182	Elf_Addr addr;
183	Elf_Addr addend;
184	Elf_Word rtype, symidx;
185	const Elf_Rela *rela;
186	int error;
187
188	switch (type) {
189	case ELF_RELOC_REL:
190		panic("PPC only supports RELA relocations");
191		break;
192	case ELF_RELOC_RELA:
193		rela = (const Elf_Rela *)data;
194		where = (Elf_Addr *) ((uintptr_t)relocbase + rela->r_offset);
195		hwhere = (Elf_Half *) ((uintptr_t)relocbase + rela->r_offset);
196		addend = rela->r_addend;
197		rtype = ELF_R_TYPE(rela->r_info);
198		symidx = ELF_R_SYM(rela->r_info);
199		break;
200	default:
201		panic("elf_reloc: unknown relocation mode %d\n", type);
202	}
203
204	switch (rtype) {
205
206	case R_PPC_NONE:
207		break;
208
209	case R_PPC_ADDR32: /* word32 S + A */
210		error = lookup(lf, symidx, 1, &addr);
211		if (error != 0)
212			return -1;
213		*where = elf_relocaddr(lf, addr + addend);
214			break;
215
216	case R_PPC_ADDR16_LO: /* #lo(S) */
217		error = lookup(lf, symidx, 1, &addr);
218		if (error != 0)
219			return -1;
220		/*
221		 * addend values are sometimes relative to sections
222		 * (i.e. .rodata) in rela, where in reality they
223		 * are relative to relocbase. Detect this condition.
224		 */
225		if (addr > relocbase && addr <= (relocbase + addend))
226			addr = relocbase;
227		addr = elf_relocaddr(lf, addr + addend);
228		*hwhere = addr & 0xffff;
229		break;
230
231	case R_PPC_ADDR16_HA: /* #ha(S) */
232		error = lookup(lf, symidx, 1, &addr);
233		if (error != 0)
234			return -1;
235		/*
236		 * addend values are sometimes relative to sections
237		 * (i.e. .rodata) in rela, where in reality they
238		 * are relative to relocbase. Detect this condition.
239		 */
240		if (addr > relocbase && addr <= (relocbase + addend))
241			addr = relocbase;
242		addr = elf_relocaddr(lf, addr + addend);
243		*hwhere = ((addr >> 16) + ((addr & 0x8000) ? 1 : 0))
244		    & 0xffff;
245		break;
246
247	case R_PPC_RELATIVE: /* word32 B + A */
248		*where = elf_relocaddr(lf, relocbase + addend);
249		break;
250
251	default:
252		printf("kldload: unexpected relocation type %d\n",
253		    (int) rtype);
254		return -1;
255	}
256	return(0);
257}
258
259void
260elf_reloc_self(Elf_Dyn *dynp, Elf_Addr relocbase)
261{
262	Elf_Rela *rela = NULL, *relalim;
263	Elf_Addr relasz = 0;
264	Elf_Addr *where;
265
266	/*
267	 * Extract the rela/relasz values from the dynamic section
268	 */
269	for (; dynp->d_tag != DT_NULL; dynp++) {
270		switch (dynp->d_tag) {
271		case DT_RELA:
272			rela = (Elf_Rela *)(relocbase+dynp->d_un.d_ptr);
273			break;
274		case DT_RELASZ:
275			relasz = dynp->d_un.d_val;
276			break;
277		}
278	}
279
280	/*
281	 * Relocate these values
282	 */
283	relalim = (Elf_Rela *)((caddr_t)rela + relasz);
284	for (; rela < relalim; rela++) {
285		if (ELF_R_TYPE(rela->r_info) != R_PPC_RELATIVE)
286			continue;
287		where = (Elf_Addr *)(relocbase + rela->r_offset);
288		*where = (Elf_Addr)(relocbase + rela->r_addend);
289	}
290}
291
292int
293elf_reloc(linker_file_t lf, Elf_Addr relocbase, const void *data, int type,
294    elf_lookup_fn lookup)
295{
296
297	return (elf_reloc_internal(lf, relocbase, data, type, 0, lookup));
298}
299
300int
301elf_reloc_local(linker_file_t lf, Elf_Addr relocbase, const void *data,
302    int type, elf_lookup_fn lookup)
303{
304
305	return (elf_reloc_internal(lf, relocbase, data, type, 1, lookup));
306}
307
308int
309elf_cpu_load_file(linker_file_t lf)
310{
311	/* Only sync the cache for non-kernel modules */
312	if (lf->id != 1)
313		__syncicache(lf->address, lf->size);
314	return (0);
315}
316
317int
318elf_cpu_unload_file(linker_file_t lf __unused)
319{
320
321	return (0);
322}
323#endif
324