elf32_machdep.c revision 338867 
1/*-
2 * Copyright 1996-1998 John D. Polstra.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 *
25 * $FreeBSD: stable/11/sys/powerpc/powerpc/elf32_machdep.c 338867 2018-09-21 20:40:37Z markj $
26 */
27
28#include <sys/param.h>
29#include <sys/kernel.h>
30#include <sys/systm.h>
31
32#define __ELF_WORD_SIZE 32
33
34#include <sys/exec.h>
35#include <sys/imgact.h>
36#include <sys/malloc.h>
37#include <sys/proc.h>
38#include <sys/namei.h>
39#include <sys/fcntl.h>
40#include <sys/sysent.h>
41#include <sys/imgact_elf.h>
42#include <sys/syscall.h>
43#include <sys/signalvar.h>
44#include <sys/vnode.h>
45#include <sys/linker.h>
46
47#include <vm/vm.h>
48#include <vm/vm_param.h>
49
50#include <machine/altivec.h>
51#include <machine/cpu.h>
52#include <machine/elf.h>
53#include <machine/reg.h>
54#include <machine/md_var.h>
55
56#ifdef __powerpc64__
57#include <compat/freebsd32/freebsd32_proto.h>
58#include <compat/freebsd32/freebsd32_util.h>
59
60extern const char *freebsd32_syscallnames[];
61#endif
62
63struct sysentvec elf32_freebsd_sysvec = {
64	.sv_size	= SYS_MAXSYSCALL,
65#ifdef __powerpc64__
66	.sv_table	= freebsd32_sysent,
67#else
68	.sv_table	= sysent,
69#endif
70	.sv_mask	= 0,
71	.sv_errsize	= 0,
72	.sv_errtbl	= NULL,
73	.sv_transtrap	= NULL,
74	.sv_fixup	= __elfN(freebsd_fixup),
75	.sv_sendsig	= sendsig,
76	.sv_sigcode	= sigcode32,
77	.sv_szsigcode	= &szsigcode32,
78	.sv_name	= "FreeBSD ELF32",
79	.sv_coredump	= __elfN(coredump),
80	.sv_imgact_try	= NULL,
81	.sv_minsigstksz	= MINSIGSTKSZ,
82	.sv_pagesize	= PAGE_SIZE,
83	.sv_minuser	= VM_MIN_ADDRESS,
84	.sv_stackprot	= VM_PROT_ALL,
85#ifdef __powerpc64__
86	.sv_maxuser	= VM_MAXUSER_ADDRESS,
87	.sv_usrstack	= FREEBSD32_USRSTACK,
88	.sv_psstrings	= FREEBSD32_PS_STRINGS,
89	.sv_copyout_strings = freebsd32_copyout_strings,
90	.sv_setregs	= ppc32_setregs,
91	.sv_syscallnames = freebsd32_syscallnames,
92#else
93	.sv_maxuser	= VM_MAXUSER_ADDRESS,
94	.sv_usrstack	= USRSTACK,
95	.sv_psstrings	= PS_STRINGS,
96	.sv_copyout_strings = exec_copyout_strings,
97	.sv_setregs	= exec_setregs,
98	.sv_syscallnames = syscallnames,
99#endif
100	.sv_fixlimit	= NULL,
101	.sv_maxssiz	= NULL,
102	.sv_flags	= SV_ABI_FREEBSD | SV_ILP32 | SV_SHP,
103	.sv_set_syscall_retval = cpu_set_syscall_retval,
104	.sv_fetch_syscall_args = cpu_fetch_syscall_args,
105	.sv_shared_page_base = FREEBSD32_SHAREDPAGE,
106	.sv_shared_page_len = PAGE_SIZE,
107	.sv_schedtail	= NULL,
108	.sv_thread_detach = NULL,
109	.sv_trap	= NULL,
110};
111INIT_SYSENTVEC(elf32_sysvec, &elf32_freebsd_sysvec);
112
113static Elf32_Brandinfo freebsd_brand_info = {
114	.brand		= ELFOSABI_FREEBSD,
115	.machine	= EM_PPC,
116	.compat_3_brand	= "FreeBSD",
117	.emul_path	= NULL,
118	.interp_path	= "/libexec/ld-elf.so.1",
119	.sysvec		= &elf32_freebsd_sysvec,
120#ifdef __powerpc64__
121	.interp_newpath	= "/libexec/ld-elf32.so.1",
122#else
123	.interp_newpath	= NULL,
124#endif
125	.brand_note	= &elf32_freebsd_brandnote,
126	.flags		= BI_CAN_EXEC_DYN | BI_BRAND_NOTE
127};
128
129SYSINIT(elf32, SI_SUB_EXEC, SI_ORDER_FIRST,
130    (sysinit_cfunc_t) elf32_insert_brand_entry,
131    &freebsd_brand_info);
132
133static Elf32_Brandinfo freebsd_brand_oinfo = {
134	.brand		= ELFOSABI_FREEBSD,
135	.machine	= EM_PPC,
136	.compat_3_brand	= "FreeBSD",
137	.emul_path	= NULL,
138	.interp_path	= "/usr/libexec/ld-elf.so.1",
139	.sysvec		= &elf32_freebsd_sysvec,
140	.interp_newpath	= NULL,
141	.brand_note	= &elf32_freebsd_brandnote,
142	.flags		= BI_CAN_EXEC_DYN | BI_BRAND_NOTE
143};
144
145SYSINIT(oelf32, SI_SUB_EXEC, SI_ORDER_ANY,
146	(sysinit_cfunc_t) elf32_insert_brand_entry,
147	&freebsd_brand_oinfo);
148
149void elf_reloc_self(Elf_Dyn *dynp, Elf_Addr relocbase);
150
151void
152elf32_dump_thread(struct thread *td, void *dst, size_t *off)
153{
154	size_t len;
155	struct pcb *pcb;
156
157	len = 0;
158	pcb = td->td_pcb;
159	if (pcb->pcb_flags & PCB_VEC) {
160		save_vec_nodrop(td);
161		if (dst != NULL) {
162			len += elf32_populate_note(NT_PPC_VMX,
163			    &pcb->pcb_vec, dst,
164			    sizeof(pcb->pcb_vec), NULL);
165		} else
166			len += elf32_populate_note(NT_PPC_VMX, NULL, NULL,
167			    sizeof(pcb->pcb_vec), NULL);
168	}
169	*off = len;
170}
171
172#ifndef __powerpc64__
173bool
174elf_is_ifunc_reloc(Elf_Size r_info __unused)
175{
176
177	return (false);
178}
179
180/* Process one elf relocation with addend. */
181static int
182elf_reloc_internal(linker_file_t lf, Elf_Addr relocbase, const void *data,
183    int type, int local, elf_lookup_fn lookup)
184{
185	Elf_Addr *where;
186	Elf_Half *hwhere;
187	Elf_Addr addr;
188	Elf_Addr addend;
189	Elf_Word rtype, symidx;
190	const Elf_Rela *rela;
191	int error;
192
193	switch (type) {
194	case ELF_RELOC_REL:
195		panic("PPC only supports RELA relocations");
196		break;
197	case ELF_RELOC_RELA:
198		rela = (const Elf_Rela *)data;
199		where = (Elf_Addr *) ((uintptr_t)relocbase + rela->r_offset);
200		hwhere = (Elf_Half *) ((uintptr_t)relocbase + rela->r_offset);
201		addend = rela->r_addend;
202		rtype = ELF_R_TYPE(rela->r_info);
203		symidx = ELF_R_SYM(rela->r_info);
204		break;
205	default:
206		panic("elf_reloc: unknown relocation mode %d\n", type);
207	}
208
209	switch (rtype) {
210
211	case R_PPC_NONE:
212		break;
213
214	case R_PPC_ADDR32: /* word32 S + A */
215		error = lookup(lf, symidx, 1, &addr);
216		if (error != 0)
217			return -1;
218		*where = elf_relocaddr(lf, addr + addend);
219			break;
220
221	case R_PPC_ADDR16_LO: /* #lo(S) */
222		error = lookup(lf, symidx, 1, &addr);
223		if (error != 0)
224			return -1;
225		/*
226		 * addend values are sometimes relative to sections
227		 * (i.e. .rodata) in rela, where in reality they
228		 * are relative to relocbase. Detect this condition.
229		 */
230		if (addr > relocbase && addr <= (relocbase + addend))
231			addr = relocbase;
232		addr = elf_relocaddr(lf, addr + addend);
233		*hwhere = addr & 0xffff;
234		break;
235
236	case R_PPC_ADDR16_HA: /* #ha(S) */
237		error = lookup(lf, symidx, 1, &addr);
238		if (error != 0)
239			return -1;
240		/*
241		 * addend values are sometimes relative to sections
242		 * (i.e. .rodata) in rela, where in reality they
243		 * are relative to relocbase. Detect this condition.
244		 */
245		if (addr > relocbase && addr <= (relocbase + addend))
246			addr = relocbase;
247		addr = elf_relocaddr(lf, addr + addend);
248		*hwhere = ((addr >> 16) + ((addr & 0x8000) ? 1 : 0))
249		    & 0xffff;
250		break;
251
252	case R_PPC_RELATIVE: /* word32 B + A */
253		*where = elf_relocaddr(lf, relocbase + addend);
254		break;
255
256	default:
257		printf("kldload: unexpected relocation type %d\n",
258		    (int) rtype);
259		return -1;
260	}
261	return(0);
262}
263
264void
265elf_reloc_self(Elf_Dyn *dynp, Elf_Addr relocbase)
266{
267	Elf_Rela *rela = NULL, *relalim;
268	Elf_Addr relasz = 0;
269	Elf_Addr *where;
270
271	/*
272	 * Extract the rela/relasz values from the dynamic section
273	 */
274	for (; dynp->d_tag != DT_NULL; dynp++) {
275		switch (dynp->d_tag) {
276		case DT_RELA:
277			rela = (Elf_Rela *)(relocbase+dynp->d_un.d_ptr);
278			break;
279		case DT_RELASZ:
280			relasz = dynp->d_un.d_val;
281			break;
282		}
283	}
284
285	/*
286	 * Relocate these values
287	 */
288	relalim = (Elf_Rela *)((caddr_t)rela + relasz);
289	for (; rela < relalim; rela++) {
290		if (ELF_R_TYPE(rela->r_info) != R_PPC_RELATIVE)
291			continue;
292		where = (Elf_Addr *)(relocbase + rela->r_offset);
293		*where = (Elf_Addr)(relocbase + rela->r_addend);
294	}
295}
296
297int
298elf_reloc(linker_file_t lf, Elf_Addr relocbase, const void *data, int type,
299    elf_lookup_fn lookup)
300{
301
302	return (elf_reloc_internal(lf, relocbase, data, type, 0, lookup));
303}
304
305int
306elf_reloc_local(linker_file_t lf, Elf_Addr relocbase, const void *data,
307    int type, elf_lookup_fn lookup)
308{
309
310	return (elf_reloc_internal(lf, relocbase, data, type, 1, lookup));
311}
312
313int
314elf_cpu_load_file(linker_file_t lf)
315{
316	/* Only sync the cache for non-kernel modules */
317	if (lf->id != 1)
318		__syncicache(lf->address, lf->size);
319	return (0);
320}
321
322int
323elf_cpu_unload_file(linker_file_t lf __unused)
324{
325
326	return (0);
327}
328#endif
329