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>
48 #include <sys/sysctl.h>
49 #include <sys/sysent.h>
50 #include <sys/imgact_elf.h>
51 #include <sys/syscall.h>
52 #include <sys/signalvar.h>
53 #include <sys/vnode.h>
57 #include <vm/vm_param.h>
59 #include <machine/elf.h>
60 #include <machine/md_var.h>
64 static struct sysentvec elf64_freebsd_sysvec = {
65 .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_elf_core_osabi = ELFOSABI_FREEBSD,
74 .sv_elf_core_abi_vendor = FREEBSD_ABI_VENDOR,
75 .sv_elf_core_prepare_notes = __elfN(prepare_notes),
76 .sv_minsigstksz = MINSIGSTKSZ,
77 .sv_minuser = VM_MIN_ADDRESS,
78 .sv_maxuser = 0, /* Filled in during boot. */
79 .sv_usrstack = 0, /* Filled in during boot. */
80 .sv_psstrings = 0, /* Filled in during boot. */
81 .sv_psstringssz = sizeof(struct ps_strings),
82 .sv_stackprot = VM_PROT_READ | VM_PROT_WRITE,
83 .sv_copyout_auxargs = __elfN(freebsd_copyout_auxargs),
84 .sv_copyout_strings = exec_copyout_strings,
85 .sv_setregs = exec_setregs,
88 .sv_flags = SV_ABI_FREEBSD | SV_LP64 | SV_SHP | SV_TIMEKEEP |
89 SV_ASLR | SV_RNG_SEED_VER,
90 .sv_set_syscall_retval = cpu_set_syscall_retval,
91 .sv_fetch_syscall_args = cpu_fetch_syscall_args,
92 .sv_syscallnames = syscallnames,
93 .sv_shared_page_base = 0, /* Filled in during boot. */
94 .sv_shared_page_len = PAGE_SIZE,
96 .sv_thread_detach = NULL,
98 .sv_hwcap = &elf_hwcap,
99 .sv_onexec_old = exec_onexec_old,
100 .sv_onexit = exit_onexit,
101 .sv_regset_begin = SET_BEGIN(__elfN(regset)),
102 .sv_regset_end = SET_LIMIT(__elfN(regset)),
104 INIT_SYSENTVEC(elf64_sysvec, &elf64_freebsd_sysvec);
106 static Elf64_Brandinfo freebsd_brand_info = {
107 .brand = ELFOSABI_FREEBSD,
109 .compat_3_brand = "FreeBSD",
110 .interp_path = "/libexec/ld-elf.so.1",
111 .sysvec = &elf64_freebsd_sysvec,
112 .interp_newpath = NULL,
113 .brand_note = &elf64_freebsd_brandnote,
114 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE
116 SYSINIT(elf64, SI_SUB_EXEC, SI_ORDER_FIRST,
117 (sysinit_cfunc_t)elf64_insert_brand_entry, &freebsd_brand_info);
120 elf64_register_sysvec(void *arg)
122 struct sysentvec *sv;
127 sv->sv_maxuser = VM_MAX_USER_ADDRESS_SV48;
128 sv->sv_usrstack = USRSTACK_SV48;
129 sv->sv_psstrings = PS_STRINGS_SV48;
130 sv->sv_shared_page_base = SHAREDPAGE_SV48;
133 sv->sv_maxuser = VM_MAX_USER_ADDRESS_SV39;
134 sv->sv_usrstack = USRSTACK_SV39;
135 sv->sv_psstrings = PS_STRINGS_SV39;
136 sv->sv_shared_page_base = SHAREDPAGE_SV39;
140 SYSINIT(elf64_register_sysvec, SI_SUB_VM, SI_ORDER_ANY, elf64_register_sysvec,
141 &elf64_freebsd_sysvec);
143 static bool debug_kld;
144 SYSCTL_BOOL(_debug, OID_AUTO, kld_reloc, CTLFLAG_RW, &debug_kld, 0,
145 "Activate debug prints in elf_reloc_internal()");
147 struct type2str_ent {
153 elf64_dump_thread(struct thread *td, void *dst, size_t *off)
159 * Following 4 functions are used to manipulate bits on 32bit integer value.
160 * FIXME: I implemetend for ease-to-understand rather than for well-optimized.
163 gen_bitmask(int msb, int lsb)
167 if (msb == sizeof(mask) * 8 - 1)
170 mask = (1U << (msb + 1)) - 1;
173 mask &= ~((1U << lsb) - 1);
179 extract_bits(uint32_t x, int msb, int lsb)
183 mask = gen_bitmask(msb, lsb);
192 insert_bits(uint32_t d, uint32_t s, int msb, int lsb)
196 mask = gen_bitmask(msb, lsb);
207 insert_imm(uint32_t insn, uint32_t imm, int imm_msb, int imm_lsb,
213 v = extract_bits(imm, imm_msb, imm_lsb);
214 insn_msb = (imm_msb - imm_lsb) + insn_lsb;
216 return (insert_bits(insn, v, insn_msb, insn_lsb));
220 * The RISC-V ISA is designed so that all of immediate values are
222 * An immediate value is sometimes generated at runtime by adding
223 * 12bit sign integer and 20bit signed integer. This requests 20bit
224 * immediate value to be ajusted if the MSB of the 12bit immediate
225 * value is asserted (sign-extended value is treated as negative value).
227 * For example, 0x123800 can be calculated by adding upper 20 bit of
228 * 0x124000 and sign-extended 12bit immediate whose bit pattern is
232 * = (0x123000 + 0x1000) + (-0x1000 + 0x800)
233 * = (0x123000 + 0x1000) + (0xff...ff800)
234 * = 0x124000 + sign-extention(0x800)
237 calc_hi20_imm(uint32_t value)
240 * There is the arithmetical hack that can remove conditional
241 * statement. But I implement it in straightforward way.
243 if ((value & 0x800) != 0)
245 return (value & ~0xfff);
248 static const struct type2str_ent t2s[] = {
249 { R_RISCV_NONE, "R_RISCV_NONE" },
250 { R_RISCV_64, "R_RISCV_64" },
251 { R_RISCV_JUMP_SLOT, "R_RISCV_JUMP_SLOT" },
252 { R_RISCV_RELATIVE, "R_RISCV_RELATIVE" },
253 { R_RISCV_JAL, "R_RISCV_JAL" },
254 { R_RISCV_CALL, "R_RISCV_CALL" },
255 { R_RISCV_PCREL_HI20, "R_RISCV_PCREL_HI20" },
256 { R_RISCV_PCREL_LO12_I, "R_RISCV_PCREL_LO12_I" },
257 { R_RISCV_PCREL_LO12_S, "R_RISCV_PCREL_LO12_S" },
258 { R_RISCV_HI20, "R_RISCV_HI20" },
259 { R_RISCV_LO12_I, "R_RISCV_LO12_I" },
260 { R_RISCV_LO12_S, "R_RISCV_LO12_S" },
264 reloctype_to_str(int type)
268 for (i = 0; i < sizeof(t2s) / sizeof(t2s[0]); ++i) {
269 if (type == t2s[i].type)
277 elf_is_ifunc_reloc(Elf_Size r_info __unused)
284 * Currently kernel loadable module for RISCV is compiled with -fPIC option.
285 * (see also additional CFLAGS definition for RISCV in sys/conf/kmod.mk)
286 * Only R_RISCV_64, R_RISCV_JUMP_SLOT and RISCV_RELATIVE are emitted in
287 * the module. Other relocations will be processed when kernel loadable
288 * modules are built in non-PIC.
290 * FIXME: only RISCV64 is supported.
293 elf_reloc_internal(linker_file_t lf, Elf_Addr relocbase, const void *data,
294 int type, int local, elf_lookup_fn lookup)
296 Elf_Size rtype, symidx;
297 const Elf_Rela *rela;
310 rela = (const Elf_Rela *)data;
311 where = (Elf_Addr *)(relocbase + rela->r_offset);
312 insn32p = (uint32_t *)where;
313 addend = rela->r_addend;
314 rtype = ELF_R_TYPE(rela->r_info);
315 symidx = ELF_R_SYM(rela->r_info);
318 printf("%s:%d unknown reloc type %d\n",
319 __FUNCTION__, __LINE__, type);
328 error = lookup(lf, symidx, 1, &addr);
333 *where = addr + addend;
335 printf("%p %c %-24s %016lx -> %016lx\n", where,
336 (local ? 'l' : 'g'), reloctype_to_str(rtype),
340 case R_RISCV_JUMP_SLOT:
341 error = lookup(lf, symidx, 1, &addr);
348 printf("%p %c %-24s %016lx -> %016lx\n", where,
349 (local ? 'l' : 'g'), reloctype_to_str(rtype),
353 case R_RISCV_RELATIVE:
355 *where = elf_relocaddr(lf, relocbase + addend);
357 printf("%p %c %-24s %016lx -> %016lx\n", where,
358 (local ? 'l' : 'g'), reloctype_to_str(rtype),
363 error = lookup(lf, symidx, 1, &addr);
367 val = addr - (Elf_Addr)where;
368 if (val <= -(1UL << 20) || (1UL << 20) <= val) {
369 printf("kldload: huge offset against R_RISCV_JAL\n");
374 *insn32p = insert_imm(*insn32p, val, 20, 20, 31);
375 *insn32p = insert_imm(*insn32p, val, 10, 1, 21);
376 *insn32p = insert_imm(*insn32p, val, 11, 11, 20);
377 *insn32p = insert_imm(*insn32p, val, 19, 12, 12);
379 printf("%p %c %-24s %08x -> %08x\n", where,
380 (local ? 'l' : 'g'), reloctype_to_str(rtype),
386 * R_RISCV_CALL relocates 8-byte region that consists
387 * of the sequence of AUIPC and JALR.
389 /* Calculate and check the pc relative offset. */
390 error = lookup(lf, symidx, 1, &addr);
394 val = addr - (Elf_Addr)where;
395 if (val <= -(1UL << 32) || (1UL << 32) <= val) {
396 printf("kldload: huge offset against R_RISCV_CALL\n");
400 /* Relocate AUIPC. */
401 before32 = insn32p[0];
402 imm20 = calc_hi20_imm(val);
403 insn32p[0] = insert_imm(insn32p[0], imm20, 31, 12, 12);
406 before32_1 = insn32p[1];
407 insn32p[1] = insert_imm(insn32p[1], val, 11, 0, 20);
409 printf("%p %c %-24s %08x %08x -> %08x %08x\n", where,
410 (local ? 'l' : 'g'), reloctype_to_str(rtype),
411 before32, insn32p[0], before32_1, insn32p[1]);
414 case R_RISCV_PCREL_HI20:
415 error = lookup(lf, symidx, 1, &addr);
419 val = addr - (Elf_Addr)where;
420 insn32p = (uint32_t *)where;
422 imm20 = calc_hi20_imm(val);
423 *insn32p = insert_imm(*insn32p, imm20, 31, 12, 12);
425 printf("%p %c %-24s %08x -> %08x\n", where,
426 (local ? 'l' : 'g'), reloctype_to_str(rtype),
430 case R_RISCV_PCREL_LO12_I:
431 error = lookup(lf, symidx, 1, &addr);
435 val = addr - (Elf_Addr)where;
436 insn32p = (uint32_t *)where;
438 *insn32p = insert_imm(*insn32p, addr, 11, 0, 20);
440 printf("%p %c %-24s %08x -> %08x\n", where,
441 (local ? 'l' : 'g'), reloctype_to_str(rtype),
445 case R_RISCV_PCREL_LO12_S:
446 error = lookup(lf, symidx, 1, &addr);
450 val = addr - (Elf_Addr)where;
451 insn32p = (uint32_t *)where;
453 *insn32p = insert_imm(*insn32p, addr, 11, 5, 25);
454 *insn32p = insert_imm(*insn32p, addr, 4, 0, 7);
456 printf("%p %c %-24s %08x -> %08x\n", where,
457 (local ? 'l' : 'g'), reloctype_to_str(rtype),
462 error = lookup(lf, symidx, 1, &addr);
467 insn32p = (uint32_t *)where;
469 imm20 = calc_hi20_imm(val);
470 *insn32p = insert_imm(*insn32p, imm20, 31, 12, 12);
472 printf("%p %c %-24s %08x -> %08x\n", where,
473 (local ? 'l' : 'g'), reloctype_to_str(rtype),
478 error = lookup(lf, symidx, 1, &addr);
483 insn32p = (uint32_t *)where;
485 *insn32p = insert_imm(*insn32p, addr, 11, 0, 20);
487 printf("%p %c %-24s %08x -> %08x\n", where,
488 (local ? 'l' : 'g'), reloctype_to_str(rtype),
493 error = lookup(lf, symidx, 1, &addr);
498 insn32p = (uint32_t *)where;
500 *insn32p = insert_imm(*insn32p, addr, 11, 5, 25);
501 *insn32p = insert_imm(*insn32p, addr, 4, 0, 7);
503 printf("%p %c %-24s %08x -> %08x\n", where,
504 (local ? 'l' : 'g'), reloctype_to_str(rtype),
509 printf("kldload: unexpected relocation type %ld, "
510 "symbol index %ld\n", rtype, symidx);
518 elf_reloc(linker_file_t lf, Elf_Addr relocbase, const void *data, int type,
519 elf_lookup_fn lookup)
522 return (elf_reloc_internal(lf, relocbase, data, type, 0, lookup));
526 elf_reloc_local(linker_file_t lf, Elf_Addr relocbase, const void *data,
527 int type, elf_lookup_fn lookup)
530 return (elf_reloc_internal(lf, relocbase, data, type, 1, lookup));
534 elf_cpu_load_file(linker_file_t lf __unused)
541 elf_cpu_unload_file(linker_file_t lf __unused)
548 elf_cpu_parse_dynamic(caddr_t loadbase __unused, Elf_Dyn *dynamic __unused)