2 * Copyright 1996-1998 John D. Polstra.
3 * Copyright (c) 2015 Ruslan Bukin <br@bsdpad.com>
4 * Copyright (c) 2016 Yukishige Shibata <y-shibat@mtd.biglobe.ne.jp>
7 * Portions of this software were developed by SRI International and the
8 * University of Cambridge Computer Laboratory under DARPA/AFRL contract
9 * FA8750-10-C-0237 ("CTSRD"), as part of the DARPA CRASH research programme.
11 * Portions of this software were developed by the University of Cambridge
12 * Computer Laboratory as part of the CTSRD Project, with support from the
13 * UK Higher Education Innovation Fund (HEIF).
15 * Redistribution and use in source and binary forms, with or without
16 * modification, are permitted provided that the following conditions
18 * 1. Redistributions of source code must retain the above copyright
19 * notice, this list of conditions and the following disclaimer.
20 * 2. Redistributions in binary form must reproduce the above copyright
21 * notice, this list of conditions and the following disclaimer in the
22 * documentation and/or other materials provided with the distribution.
24 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD$");
40 #include <sys/param.h>
41 #include <sys/kernel.h>
42 #include <sys/systm.h>
44 #include <sys/imgact.h>
45 #include <sys/linker.h>
47 #include <sys/sysctl.h>
48 #include <sys/sysent.h>
49 #include <sys/imgact_elf.h>
50 #include <sys/syscall.h>
51 #include <sys/signalvar.h>
52 #include <sys/vnode.h>
56 #include <vm/vm_param.h>
58 #include <machine/elf.h>
59 #include <machine/md_var.h>
61 struct sysentvec elf64_freebsd_sysvec = {
62 .sv_size = SYS_MAXSYSCALL,
67 .sv_fixup = __elfN(freebsd_fixup),
68 .sv_sendsig = sendsig,
69 .sv_sigcode = sigcode,
70 .sv_szsigcode = &szsigcode,
71 .sv_name = "FreeBSD ELF64",
72 .sv_coredump = __elfN(coredump),
73 .sv_imgact_try = NULL,
74 .sv_minsigstksz = MINSIGSTKSZ,
75 .sv_minuser = VM_MIN_ADDRESS,
76 .sv_maxuser = VM_MAXUSER_ADDRESS,
77 .sv_usrstack = USRSTACK,
78 .sv_psstrings = PS_STRINGS,
79 .sv_stackprot = VM_PROT_READ | VM_PROT_WRITE,
80 .sv_copyout_strings = exec_copyout_strings,
81 .sv_setregs = exec_setregs,
84 .sv_flags = SV_ABI_FREEBSD | SV_LP64 | SV_SHP | SV_ASLR,
85 .sv_set_syscall_retval = cpu_set_syscall_retval,
86 .sv_fetch_syscall_args = cpu_fetch_syscall_args,
87 .sv_syscallnames = syscallnames,
88 .sv_shared_page_base = SHAREDPAGE,
89 .sv_shared_page_len = PAGE_SIZE,
91 .sv_thread_detach = NULL,
94 INIT_SYSENTVEC(elf64_sysvec, &elf64_freebsd_sysvec);
96 static Elf64_Brandinfo freebsd_brand_info = {
97 .brand = ELFOSABI_FREEBSD,
99 .compat_3_brand = "FreeBSD",
101 .interp_path = "/libexec/ld-elf.so.1",
102 .sysvec = &elf64_freebsd_sysvec,
103 .interp_newpath = NULL,
104 .brand_note = &elf64_freebsd_brandnote,
105 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE
108 SYSINIT(elf64, SI_SUB_EXEC, SI_ORDER_FIRST,
109 (sysinit_cfunc_t) elf64_insert_brand_entry,
110 &freebsd_brand_info);
112 static int debug_kld;
113 SYSCTL_INT(_kern, OID_AUTO, debug_kld,
114 CTLFLAG_RW, &debug_kld, 0,
115 "Activate debug prints in elf_reloc_internal()");
117 struct type2str_ent {
123 elf64_dump_thread(struct thread *td, void *dst, size_t *off)
129 * Following 4 functions are used to manupilate bits on 32bit interger value.
130 * FIXME: I implemetend for ease-to-understand rather than for well-optimized.
133 gen_bitmask(int msb, int lsb)
137 if (msb == sizeof(mask) * 8 - 1)
140 mask = (1U << (msb + 1)) - 1;
143 mask &= ~((1U << lsb) - 1);
149 extract_bits(uint32_t x, int msb, int lsb)
153 mask = gen_bitmask(msb, lsb);
162 insert_bits(uint32_t d, uint32_t s, int msb, int lsb)
166 mask = gen_bitmask(msb, lsb);
177 insert_imm(uint32_t insn, uint32_t imm, int imm_msb, int imm_lsb,
183 v = extract_bits(imm, imm_msb, imm_lsb);
184 insn_msb = (imm_msb - imm_lsb) + insn_lsb;
186 return (insert_bits(insn, v, insn_msb, insn_lsb));
190 * The RISC-V ISA is designed so that all of immediate values are
192 * An immediate value is sometimes generated at runtime by adding
193 * 12bit sign integer and 20bit signed integer. This requests 20bit
194 * immediate value to be ajusted if the MSB of the 12bit immediate
195 * value is asserted (sign-extended value is treated as negative value).
197 * For example, 0x123800 can be calculated by adding upper 20 bit of
198 * 0x124000 and sign-extended 12bit immediate whose bit pattern is
202 * = (0x123000 + 0x1000) + (-0x1000 + 0x800)
203 * = (0x123000 + 0x1000) + (0xff...ff800)
204 * = 0x124000 + sign-extention(0x800)
207 calc_hi20_imm(uint32_t value)
210 * There is the arithmetical hack that can remove conditional
211 * statement. But I implement it in straightforward way.
213 if ((value & 0x800) != 0)
215 return (value & ~0xfff);
218 static const struct type2str_ent t2s[] = {
219 { R_RISCV_NONE, "R_RISCV_NONE" },
220 { R_RISCV_64, "R_RISCV_64" },
221 { R_RISCV_JUMP_SLOT, "R_RISCV_JUMP_SLOT" },
222 { R_RISCV_RELATIVE, "R_RISCV_RELATIVE" },
223 { R_RISCV_JAL, "R_RISCV_JAL" },
224 { R_RISCV_CALL, "R_RISCV_CALL" },
225 { R_RISCV_PCREL_HI20, "R_RISCV_PCREL_HI20" },
226 { R_RISCV_PCREL_LO12_I, "R_RISCV_PCREL_LO12_I" },
227 { R_RISCV_PCREL_LO12_S, "R_RISCV_PCREL_LO12_S" },
228 { R_RISCV_HI20, "R_RISCV_HI20" },
229 { R_RISCV_LO12_I, "R_RISCV_LO12_I" },
230 { R_RISCV_LO12_S, "R_RISCV_LO12_S" },
234 reloctype_to_str(int type)
238 for (i = 0; i < sizeof(t2s) / sizeof(t2s[0]); ++i) {
239 if (type == t2s[i].type)
247 elf_is_ifunc_reloc(Elf_Size r_info __unused)
254 * Currently kernel loadable module for RISCV is compiled with -fPIC option.
255 * (see also additional CFLAGS definition for RISCV in sys/conf/kmod.mk)
256 * Only R_RISCV_64, R_RISCV_JUMP_SLOT and RISCV_RELATIVE are emitted in
257 * the module. Other relocations will be processed when kernel loadable
258 * modules are built in non-PIC.
260 * FIXME: only RISCV64 is supported.
263 elf_reloc_internal(linker_file_t lf, Elf_Addr relocbase, const void *data,
264 int type, int local, elf_lookup_fn lookup)
266 Elf_Size rtype, symidx;
267 const Elf_Rela *rela;
280 rela = (const Elf_Rela *)data;
281 where = (Elf_Addr *)(relocbase + rela->r_offset);
282 insn32p = (uint32_t*)where;
283 addend = rela->r_addend;
284 rtype = ELF_R_TYPE(rela->r_info);
285 symidx = ELF_R_SYM(rela->r_info);
288 printf("%s:%d unknown reloc type %d\n",
289 __FUNCTION__, __LINE__, type);
298 case R_RISCV_JUMP_SLOT:
299 error = lookup(lf, symidx, 1, &addr);
309 printf("%p %c %-24s %016lx -> %016lx\n",
312 reloctype_to_str(rtype),
316 case R_RISCV_RELATIVE:
319 *where = elf_relocaddr(lf, relocbase + addend);
322 printf("%p %c %-24s %016lx -> %016lx\n",
325 reloctype_to_str(rtype),
330 error = lookup(lf, symidx, 1, &addr);
334 val = addr - (Elf_Addr)where;
335 if ((val <= -(1UL << 20) || (1UL << 20) <= val)) {
336 printf("kldload: huge offset against R_RISCV_JAL\n");
341 *insn32p = insert_imm(*insn32p, val, 20, 20, 31);
342 *insn32p = insert_imm(*insn32p, val, 10, 1, 21);
343 *insn32p = insert_imm(*insn32p, val, 11, 11, 20);
344 *insn32p = insert_imm(*insn32p, val, 19, 12, 12);
347 printf("%p %c %-24s %08x -> %08x\n",
350 reloctype_to_str(rtype),
356 * R_RISCV_CALL relocates 8-byte region that consists
357 * of the sequence of AUIPC and JALR.
359 /* calculate and check the pc relative offset. */
360 error = lookup(lf, symidx, 1, &addr);
363 val = addr - (Elf_Addr)where;
364 if ((val <= -(1UL << 32) || (1UL << 32) <= val)) {
365 printf("kldload: huge offset against R_RISCV_CALL\n");
369 /* Relocate AUIPC. */
370 before32 = insn32p[0];
371 imm20 = calc_hi20_imm(val);
372 insn32p[0] = insert_imm(insn32p[0], imm20, 31, 12, 12);
375 before32_1 = insn32p[1];
376 insn32p[1] = insert_imm(insn32p[1], val, 11, 0, 20);
379 printf("%p %c %-24s %08x %08x -> %08x %08x\n",
382 reloctype_to_str(rtype),
383 before32, insn32p[0],
384 before32_1, insn32p[1]);
387 case R_RISCV_PCREL_HI20:
388 val = addr - (Elf_Addr)where;
389 insn32p = (uint32_t*)where;
391 imm20 = calc_hi20_imm(val);
392 *insn32p = insert_imm(*insn32p, imm20, 31, 12, 12);
395 printf("%p %c %-24s %08x -> %08x\n",
398 reloctype_to_str(rtype),
402 case R_RISCV_PCREL_LO12_I:
403 val = addr - (Elf_Addr)where;
404 insn32p = (uint32_t*)where;
406 *insn32p = insert_imm(*insn32p, addr, 11, 0, 20);
409 printf("%p %c %-24s %08x -> %08x\n",
412 reloctype_to_str(rtype),
416 case R_RISCV_PCREL_LO12_S:
417 val = addr - (Elf_Addr)where;
418 insn32p = (uint32_t*)where;
420 *insn32p = insert_imm(*insn32p, addr, 11, 5, 25);
421 *insn32p = insert_imm(*insn32p, addr, 4, 0, 7);
423 printf("%p %c %-24s %08x -> %08x\n",
426 reloctype_to_str(rtype),
431 error = lookup(lf, symidx, 1, &addr);
435 insn32p = (uint32_t*)where;
437 imm20 = calc_hi20_imm(val);
438 *insn32p = insert_imm(*insn32p, imm20, 31, 12, 12);
441 printf("%p %c %-24s %08x -> %08x\n",
444 reloctype_to_str(rtype),
449 error = lookup(lf, symidx, 1, &addr);
454 insn32p = (uint32_t*)where;
456 *insn32p = insert_imm(*insn32p, addr, 11, 0, 20);
459 printf("%p %c %-24s %08x -> %08x\n",
462 reloctype_to_str(rtype),
467 error = lookup(lf, symidx, 1, &addr);
472 insn32p = (uint32_t*)where;
474 *insn32p = insert_imm(*insn32p, addr, 11, 5, 25);
475 *insn32p = insert_imm(*insn32p, addr, 4, 0, 7);
478 printf("%p %c %-24s %08x -> %08x\n",
481 reloctype_to_str(rtype),
486 printf("kldload: unexpected relocation type %ld\n", rtype);
494 elf_reloc(linker_file_t lf, Elf_Addr relocbase, const void *data, int type,
495 elf_lookup_fn lookup)
498 return (elf_reloc_internal(lf, relocbase, data, type, 0, lookup));
502 elf_reloc_local(linker_file_t lf, Elf_Addr relocbase, const void *data,
503 int type, elf_lookup_fn lookup)
506 return (elf_reloc_internal(lf, relocbase, data, type, 1, lookup));
510 elf_cpu_load_file(linker_file_t lf __unused)
517 elf_cpu_unload_file(linker_file_t lf __unused)