Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* Kernel module help for PPC64. |
| 2 | Copyright (C) 2001, 2003 Rusty Russell IBM Corporation. |
| 3 | |
| 4 | This program is free software; you can redistribute it and/or modify |
| 5 | it under the terms of the GNU General Public License as published by |
| 6 | the Free Software Foundation; either version 2 of the License, or |
| 7 | (at your option) any later version. |
| 8 | |
| 9 | This program is distributed in the hope that it will be useful, |
| 10 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 12 | GNU General Public License for more details. |
| 13 | |
| 14 | You should have received a copy of the GNU General Public License |
| 15 | along with this program; if not, write to the Free Software |
| 16 | Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| 17 | */ |
Anton Blanchard | c7d1f6a | 2014-09-17 14:39:35 +1000 | [diff] [blame] | 18 | |
| 19 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| 20 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 21 | #include <linux/module.h> |
| 22 | #include <linux/elf.h> |
| 23 | #include <linux/moduleloader.h> |
| 24 | #include <linux/err.h> |
| 25 | #include <linux/vmalloc.h> |
Steven Rostedt | f48cb8b | 2008-11-14 20:47:03 -0800 | [diff] [blame] | 26 | #include <linux/ftrace.h> |
Jeremy Fitzhardinge | 73c9cea | 2006-12-08 03:30:41 -0800 | [diff] [blame] | 27 | #include <linux/bug.h> |
Anton Blanchard | 83775b8 | 2014-04-03 20:00:43 +1100 | [diff] [blame] | 28 | #include <linux/uaccess.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 29 | #include <asm/module.h> |
Benjamin Herrenschmidt | 21c4ff8 | 2006-10-20 11:47:19 +1000 | [diff] [blame] | 30 | #include <asm/firmware.h> |
Michael Ellerman | b7bcda6 | 2008-06-24 11:32:35 +1000 | [diff] [blame] | 31 | #include <asm/code-patching.h> |
Emil Medve | eda09fb | 2007-11-14 03:24:04 +1100 | [diff] [blame] | 32 | #include <linux/sort.h> |
Robert Jennings | b88c476 | 2013-10-28 09:20:51 -0500 | [diff] [blame] | 33 | #include <asm/setup.h> |
Michael Ellerman | 336a7b5 | 2016-03-03 15:26:56 +1100 | [diff] [blame] | 34 | #include <asm/sections.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 35 | |
| 36 | /* FIXME: We don't do .init separately. To do this, we'd need to have |
| 37 | a separate r2 value in the init and core section, and stub between |
| 38 | them, too. |
| 39 | |
| 40 | Using a magic allocator which places modules within 32MB solves |
| 41 | this, and makes other things simpler. Anton? |
| 42 | --RR. */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 43 | |
Michael Ellerman | f55d966 | 2016-06-06 22:26:10 +0530 | [diff] [blame] | 44 | #ifdef PPC64_ELF_ABI_v2 |
Rusty Russell | 008d7a91 | 2014-03-19 10:42:22 +1030 | [diff] [blame] | 45 | |
| 46 | /* An address is simply the address of the function. */ |
| 47 | typedef unsigned long func_desc_t; |
| 48 | |
| 49 | static func_desc_t func_desc(unsigned long addr) |
| 50 | { |
| 51 | return addr; |
| 52 | } |
| 53 | static unsigned long func_addr(unsigned long addr) |
| 54 | { |
| 55 | return addr; |
| 56 | } |
| 57 | static unsigned long stub_func_addr(func_desc_t func) |
| 58 | { |
| 59 | return func; |
| 60 | } |
| 61 | |
| 62 | /* PowerPC64 specific values for the Elf64_Sym st_other field. */ |
| 63 | #define STO_PPC64_LOCAL_BIT 5 |
| 64 | #define STO_PPC64_LOCAL_MASK (7 << STO_PPC64_LOCAL_BIT) |
| 65 | #define PPC64_LOCAL_ENTRY_OFFSET(other) \ |
| 66 | (((1 << (((other) & STO_PPC64_LOCAL_MASK) >> STO_PPC64_LOCAL_BIT)) >> 2) << 2) |
| 67 | |
| 68 | static unsigned int local_entry_offset(const Elf64_Sym *sym) |
| 69 | { |
| 70 | /* sym->st_other indicates offset to local entry point |
| 71 | * (otherwise it will assume r12 is the address of the start |
| 72 | * of function and try to derive r2 from it). */ |
| 73 | return PPC64_LOCAL_ENTRY_OFFSET(sym->st_other); |
| 74 | } |
Rusty Russell | d2fae54 | 2014-03-18 20:12:44 +1030 | [diff] [blame] | 75 | #else |
Rusty Russell | 008d7a91 | 2014-03-19 10:42:22 +1030 | [diff] [blame] | 76 | |
| 77 | /* An address is address of the OPD entry, which contains address of fn. */ |
| 78 | typedef struct ppc64_opd_entry func_desc_t; |
| 79 | |
| 80 | static func_desc_t func_desc(unsigned long addr) |
| 81 | { |
| 82 | return *(struct ppc64_opd_entry *)addr; |
| 83 | } |
| 84 | static unsigned long func_addr(unsigned long addr) |
| 85 | { |
| 86 | return func_desc(addr).funcaddr; |
| 87 | } |
| 88 | static unsigned long stub_func_addr(func_desc_t func) |
| 89 | { |
| 90 | return func.funcaddr; |
| 91 | } |
| 92 | static unsigned int local_entry_offset(const Elf64_Sym *sym) |
| 93 | { |
| 94 | return 0; |
| 95 | } |
Rusty Russell | d2fae54 | 2014-03-18 20:12:44 +1030 | [diff] [blame] | 96 | #endif |
| 97 | |
Michael Ellerman | f17c4e0 | 2016-03-03 15:26:55 +1100 | [diff] [blame] | 98 | #define STUB_MAGIC 0x73747562 /* stub */ |
| 99 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 100 | /* Like PPC32, we need little trampolines to do > 24-bit jumps (into |
| 101 | the kernel itself). But on PPC64, these need to be used for every |
| 102 | jump, actually, to reset r2 (TOC+0x8000). */ |
| 103 | struct ppc64_stub_entry |
| 104 | { |
Anton Blanchard | 83775b8 | 2014-04-03 20:00:43 +1100 | [diff] [blame] | 105 | /* 28 byte jump instruction sequence (7 instructions). We only |
| 106 | * need 6 instructions on ABIv2 but we always allocate 7 so |
| 107 | * so we don't have to modify the trampoline load instruction. */ |
Rusty Russell | 0e60e46 | 2014-03-18 17:35:28 +1030 | [diff] [blame] | 108 | u32 jump[7]; |
Michael Ellerman | f17c4e0 | 2016-03-03 15:26:55 +1100 | [diff] [blame] | 109 | /* Used by ftrace to identify stubs */ |
| 110 | u32 magic; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 111 | /* Data for the above code */ |
Rusty Russell | 008d7a91 | 2014-03-19 10:42:22 +1030 | [diff] [blame] | 112 | func_desc_t funcdata; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 113 | }; |
| 114 | |
Rusty Russell | 5c729a1 | 2014-03-18 20:13:03 +1030 | [diff] [blame] | 115 | /* |
| 116 | * PPC64 uses 24 bit jumps, but we need to jump into other modules or |
| 117 | * the kernel which may be further. So we jump to a stub. |
| 118 | * |
| 119 | * For ELFv1 we need to use this to set up the new r2 value (aka TOC |
| 120 | * pointer). For ELFv2 it's the callee's responsibility to set up the |
| 121 | * new r2, but for both we need to save the old r2. |
| 122 | * |
| 123 | * We could simply patch the new r2 value and function pointer into |
| 124 | * the stub, but it's significantly shorter to put these values at the |
| 125 | * end of the stub code, and patch the stub address (32-bits relative |
| 126 | * to the TOC ptr, r2) into the stub. |
| 127 | */ |
Anton Blanchard | 83775b8 | 2014-04-03 20:00:43 +1100 | [diff] [blame] | 128 | |
| 129 | static u32 ppc64_stub_insns[] = { |
Rusty Russell | b1ce369 | 2014-03-18 20:12:59 +1030 | [diff] [blame] | 130 | 0x3d620000, /* addis r11,r2, <high> */ |
| 131 | 0x396b0000, /* addi r11,r11, <low> */ |
Eugene Surovegin | fed8393 | 2013-09-20 11:42:20 -0700 | [diff] [blame] | 132 | /* Save current r2 value in magic place on the stack. */ |
Rusty Russell | d2fae54 | 2014-03-18 20:12:44 +1030 | [diff] [blame] | 133 | 0xf8410000|R2_STACK_OFFSET, /* std r2,R2_STACK_OFFSET(r1) */ |
Rusty Russell | b1ce369 | 2014-03-18 20:12:59 +1030 | [diff] [blame] | 134 | 0xe98b0020, /* ld r12,32(r11) */ |
Michael Ellerman | f55d966 | 2016-06-06 22:26:10 +0530 | [diff] [blame] | 135 | #ifdef PPC64_ELF_ABI_v1 |
Rusty Russell | 5c729a1 | 2014-03-18 20:13:03 +1030 | [diff] [blame] | 136 | /* Set up new r2 from function descriptor */ |
Rusty Russell | 872aa77 | 2014-05-12 17:15:02 +0930 | [diff] [blame] | 137 | 0xe84b0028, /* ld r2,40(r11) */ |
Rusty Russell | 5c729a1 | 2014-03-18 20:13:03 +1030 | [diff] [blame] | 138 | #endif |
Rusty Russell | b1ce369 | 2014-03-18 20:12:59 +1030 | [diff] [blame] | 139 | 0x7d8903a6, /* mtctr r12 */ |
Rusty Russell | d2fae54 | 2014-03-18 20:12:44 +1030 | [diff] [blame] | 140 | 0x4e800420 /* bctr */ |
Anton Blanchard | 83775b8 | 2014-04-03 20:00:43 +1100 | [diff] [blame] | 141 | }; |
| 142 | |
| 143 | #ifdef CONFIG_DYNAMIC_FTRACE |
Michael Ellerman | f17c4e0 | 2016-03-03 15:26:55 +1100 | [diff] [blame] | 144 | int module_trampoline_target(struct module *mod, unsigned long addr, |
Anton Blanchard | dd9fa16 | 2014-04-04 15:58:42 +1100 | [diff] [blame] | 145 | unsigned long *target) |
| 146 | { |
Michael Ellerman | f17c4e0 | 2016-03-03 15:26:55 +1100 | [diff] [blame] | 147 | struct ppc64_stub_entry *stub; |
| 148 | func_desc_t funcdata; |
| 149 | u32 magic; |
Anton Blanchard | dd9fa16 | 2014-04-04 15:58:42 +1100 | [diff] [blame] | 150 | |
Michael Ellerman | f17c4e0 | 2016-03-03 15:26:55 +1100 | [diff] [blame] | 151 | if (!within_module_core(addr, mod)) { |
| 152 | pr_err("%s: stub %lx not in module %s\n", __func__, addr, mod->name); |
Anton Blanchard | dd9fa16 | 2014-04-04 15:58:42 +1100 | [diff] [blame] | 153 | return -EFAULT; |
Michael Ellerman | f17c4e0 | 2016-03-03 15:26:55 +1100 | [diff] [blame] | 154 | } |
Anton Blanchard | dd9fa16 | 2014-04-04 15:58:42 +1100 | [diff] [blame] | 155 | |
Michael Ellerman | f17c4e0 | 2016-03-03 15:26:55 +1100 | [diff] [blame] | 156 | stub = (struct ppc64_stub_entry *)addr; |
Anton Blanchard | dd9fa16 | 2014-04-04 15:58:42 +1100 | [diff] [blame] | 157 | |
Michael Ellerman | f17c4e0 | 2016-03-03 15:26:55 +1100 | [diff] [blame] | 158 | if (probe_kernel_read(&magic, &stub->magic, sizeof(magic))) { |
| 159 | pr_err("%s: fault reading magic for stub %lx for %s\n", __func__, addr, mod->name); |
Anton Blanchard | dd9fa16 | 2014-04-04 15:58:42 +1100 | [diff] [blame] | 160 | return -EFAULT; |
Michael Ellerman | f17c4e0 | 2016-03-03 15:26:55 +1100 | [diff] [blame] | 161 | } |
| 162 | |
| 163 | if (magic != STUB_MAGIC) { |
| 164 | pr_err("%s: bad magic for stub %lx for %s\n", __func__, addr, mod->name); |
| 165 | return -EFAULT; |
| 166 | } |
| 167 | |
| 168 | if (probe_kernel_read(&funcdata, &stub->funcdata, sizeof(funcdata))) { |
| 169 | pr_err("%s: fault reading funcdata for stub %lx for %s\n", __func__, addr, mod->name); |
| 170 | return -EFAULT; |
| 171 | } |
| 172 | |
| 173 | *target = stub_func_addr(funcdata); |
Anton Blanchard | dd9fa16 | 2014-04-04 15:58:42 +1100 | [diff] [blame] | 174 | |
| 175 | return 0; |
| 176 | } |
Anton Blanchard | 83775b8 | 2014-04-03 20:00:43 +1100 | [diff] [blame] | 177 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 178 | |
| 179 | /* Count how many different 24-bit relocations (different symbol, |
| 180 | different addend) */ |
| 181 | static unsigned int count_relocs(const Elf64_Rela *rela, unsigned int num) |
| 182 | { |
Emil Medve | eda09fb | 2007-11-14 03:24:04 +1100 | [diff] [blame] | 183 | unsigned int i, r_info, r_addend, _count_relocs; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 184 | |
| 185 | /* FIXME: Only count external ones --RR */ |
Emil Medve | eda09fb | 2007-11-14 03:24:04 +1100 | [diff] [blame] | 186 | _count_relocs = 0; |
| 187 | r_info = 0; |
| 188 | r_addend = 0; |
| 189 | for (i = 0; i < num; i++) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 190 | /* Only count 24-bit relocs, others don't need stubs */ |
Emil Medve | eda09fb | 2007-11-14 03:24:04 +1100 | [diff] [blame] | 191 | if (ELF64_R_TYPE(rela[i].r_info) == R_PPC_REL24 && |
| 192 | (r_info != ELF64_R_SYM(rela[i].r_info) || |
| 193 | r_addend != rela[i].r_addend)) { |
| 194 | _count_relocs++; |
| 195 | r_info = ELF64_R_SYM(rela[i].r_info); |
| 196 | r_addend = rela[i].r_addend; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 197 | } |
Emil Medve | eda09fb | 2007-11-14 03:24:04 +1100 | [diff] [blame] | 198 | |
| 199 | return _count_relocs; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 200 | } |
| 201 | |
Emil Medve | eda09fb | 2007-11-14 03:24:04 +1100 | [diff] [blame] | 202 | static int relacmp(const void *_x, const void *_y) |
| 203 | { |
| 204 | const Elf64_Rela *x, *y; |
| 205 | |
| 206 | y = (Elf64_Rela *)_x; |
| 207 | x = (Elf64_Rela *)_y; |
| 208 | |
| 209 | /* Compare the entire r_info (as opposed to ELF64_R_SYM(r_info) only) to |
| 210 | * make the comparison cheaper/faster. It won't affect the sorting or |
| 211 | * the counting algorithms' performance |
| 212 | */ |
| 213 | if (x->r_info < y->r_info) |
| 214 | return -1; |
| 215 | else if (x->r_info > y->r_info) |
| 216 | return 1; |
| 217 | else if (x->r_addend < y->r_addend) |
| 218 | return -1; |
| 219 | else if (x->r_addend > y->r_addend) |
| 220 | return 1; |
| 221 | else |
| 222 | return 0; |
| 223 | } |
| 224 | |
| 225 | static void relaswap(void *_x, void *_y, int size) |
| 226 | { |
| 227 | uint64_t *x, *y, tmp; |
| 228 | int i; |
| 229 | |
| 230 | y = (uint64_t *)_x; |
| 231 | x = (uint64_t *)_y; |
| 232 | |
| 233 | for (i = 0; i < sizeof(Elf64_Rela) / sizeof(uint64_t); i++) { |
| 234 | tmp = x[i]; |
| 235 | x[i] = y[i]; |
| 236 | y[i] = tmp; |
| 237 | } |
| 238 | } |
| 239 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 240 | /* Get size of potential trampolines required. */ |
| 241 | static unsigned long get_stubs_size(const Elf64_Ehdr *hdr, |
| 242 | const Elf64_Shdr *sechdrs) |
| 243 | { |
| 244 | /* One extra reloc so it's always 0-funcaddr terminated */ |
| 245 | unsigned long relocs = 1; |
| 246 | unsigned i; |
| 247 | |
| 248 | /* Every relocated section... */ |
| 249 | for (i = 1; i < hdr->e_shnum; i++) { |
| 250 | if (sechdrs[i].sh_type == SHT_RELA) { |
Anton Blanchard | c7d1f6a | 2014-09-17 14:39:35 +1000 | [diff] [blame] | 251 | pr_debug("Found relocations in section %u\n", i); |
| 252 | pr_debug("Ptr: %p. Number: %Lu\n", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 253 | (void *)sechdrs[i].sh_addr, |
| 254 | sechdrs[i].sh_size / sizeof(Elf64_Rela)); |
Emil Medve | eda09fb | 2007-11-14 03:24:04 +1100 | [diff] [blame] | 255 | |
| 256 | /* Sort the relocation information based on a symbol and |
| 257 | * addend key. This is a stable O(n*log n) complexity |
| 258 | * alogrithm but it will reduce the complexity of |
| 259 | * count_relocs() to linear complexity O(n) |
| 260 | */ |
| 261 | sort((void *)sechdrs[i].sh_addr, |
| 262 | sechdrs[i].sh_size / sizeof(Elf64_Rela), |
| 263 | sizeof(Elf64_Rela), relacmp, relaswap); |
| 264 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 265 | relocs += count_relocs((void *)sechdrs[i].sh_addr, |
| 266 | sechdrs[i].sh_size |
| 267 | / sizeof(Elf64_Rela)); |
| 268 | } |
| 269 | } |
| 270 | |
Steven Rostedt | f48cb8b | 2008-11-14 20:47:03 -0800 | [diff] [blame] | 271 | #ifdef CONFIG_DYNAMIC_FTRACE |
| 272 | /* make the trampoline to the ftrace_caller */ |
| 273 | relocs++; |
| 274 | #endif |
| 275 | |
Anton Blanchard | c7d1f6a | 2014-09-17 14:39:35 +1000 | [diff] [blame] | 276 | pr_debug("Looks like a total of %lu stubs, max\n", relocs); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 277 | return relocs * sizeof(struct ppc64_stub_entry); |
| 278 | } |
| 279 | |
Rusty Russell | 5b12c5c | 2014-03-18 20:11:28 +1030 | [diff] [blame] | 280 | /* Still needed for ELFv2, for .TOC. */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 281 | static void dedotify_versions(struct modversion_info *vers, |
| 282 | unsigned long size) |
| 283 | { |
| 284 | struct modversion_info *end; |
| 285 | |
| 286 | for (end = (void *)vers + size; vers < end; vers++) |
Laurent Dufour | c2cbcf5 | 2014-06-24 10:53:59 +0200 | [diff] [blame] | 287 | if (vers->name[0] == '.') { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 288 | memmove(vers->name, vers->name+1, strlen(vers->name)); |
Laurent Dufour | c2cbcf5 | 2014-06-24 10:53:59 +0200 | [diff] [blame] | 289 | #ifdef ARCH_RELOCATES_KCRCTAB |
| 290 | /* The TOC symbol has no CRC computed. To avoid CRC |
| 291 | * check failing, we must force it to the expected |
| 292 | * value (see CRC check in module.c). |
| 293 | */ |
| 294 | if (!strcmp(vers->name, "TOC.")) |
| 295 | vers->crc = -(unsigned long)reloc_start; |
| 296 | #endif |
| 297 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 298 | } |
| 299 | |
Alan Modra | c153693 | 2016-01-15 20:52:22 +1100 | [diff] [blame] | 300 | /* |
| 301 | * Undefined symbols which refer to .funcname, hack to funcname. Make .TOC. |
| 302 | * seem to be defined (value set later). |
| 303 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 304 | static void dedotify(Elf64_Sym *syms, unsigned int numsyms, char *strtab) |
| 305 | { |
| 306 | unsigned int i; |
| 307 | |
| 308 | for (i = 1; i < numsyms; i++) { |
| 309 | if (syms[i].st_shndx == SHN_UNDEF) { |
| 310 | char *name = strtab + syms[i].st_name; |
Alan Modra | c153693 | 2016-01-15 20:52:22 +1100 | [diff] [blame] | 311 | if (name[0] == '.') { |
| 312 | if (strcmp(name+1, "TOC.") == 0) |
| 313 | syms[i].st_shndx = SHN_ABS; |
Andreas Schwab | f15838e | 2016-02-05 19:50:03 +0100 | [diff] [blame] | 314 | syms[i].st_name++; |
Alan Modra | c153693 | 2016-01-15 20:52:22 +1100 | [diff] [blame] | 315 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 316 | } |
| 317 | } |
| 318 | } |
| 319 | |
Rusty Russell | 4edebbe | 2014-03-18 19:59:26 +1030 | [diff] [blame] | 320 | static Elf64_Sym *find_dot_toc(Elf64_Shdr *sechdrs, |
| 321 | const char *strtab, |
| 322 | unsigned int symindex) |
| 323 | { |
| 324 | unsigned int i, numsyms; |
| 325 | Elf64_Sym *syms; |
| 326 | |
| 327 | syms = (Elf64_Sym *)sechdrs[symindex].sh_addr; |
| 328 | numsyms = sechdrs[symindex].sh_size / sizeof(Elf64_Sym); |
| 329 | |
| 330 | for (i = 1; i < numsyms; i++) { |
Alan Modra | c153693 | 2016-01-15 20:52:22 +1100 | [diff] [blame] | 331 | if (syms[i].st_shndx == SHN_ABS |
Rusty Russell | 008d7a91 | 2014-03-19 10:42:22 +1030 | [diff] [blame] | 332 | && strcmp(strtab + syms[i].st_name, "TOC.") == 0) |
Rusty Russell | 4edebbe | 2014-03-18 19:59:26 +1030 | [diff] [blame] | 333 | return &syms[i]; |
| 334 | } |
| 335 | return NULL; |
| 336 | } |
| 337 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 338 | int module_frob_arch_sections(Elf64_Ehdr *hdr, |
| 339 | Elf64_Shdr *sechdrs, |
| 340 | char *secstrings, |
| 341 | struct module *me) |
| 342 | { |
| 343 | unsigned int i; |
| 344 | |
| 345 | /* Find .toc and .stubs sections, symtab and strtab */ |
| 346 | for (i = 1; i < hdr->e_shnum; i++) { |
| 347 | char *p; |
| 348 | if (strcmp(secstrings + sechdrs[i].sh_name, ".stubs") == 0) |
| 349 | me->arch.stubs_section = i; |
| 350 | else if (strcmp(secstrings + sechdrs[i].sh_name, ".toc") == 0) |
| 351 | me->arch.toc_section = i; |
| 352 | else if (strcmp(secstrings+sechdrs[i].sh_name,"__versions")==0) |
| 353 | dedotify_versions((void *)hdr + sechdrs[i].sh_offset, |
| 354 | sechdrs[i].sh_size); |
| 355 | |
| 356 | /* We don't handle .init for the moment: rename to _init */ |
| 357 | while ((p = strstr(secstrings + sechdrs[i].sh_name, ".init"))) |
| 358 | p[0] = '_'; |
| 359 | |
| 360 | if (sechdrs[i].sh_type == SHT_SYMTAB) |
| 361 | dedotify((void *)hdr + sechdrs[i].sh_offset, |
| 362 | sechdrs[i].sh_size / sizeof(Elf64_Sym), |
| 363 | (void *)hdr |
| 364 | + sechdrs[sechdrs[i].sh_link].sh_offset); |
| 365 | } |
Alan Modra | f749eda | 2006-04-24 22:11:51 +0930 | [diff] [blame] | 366 | |
| 367 | if (!me->arch.stubs_section) { |
Anton Blanchard | c7d1f6a | 2014-09-17 14:39:35 +1000 | [diff] [blame] | 368 | pr_err("%s: doesn't contain .stubs.\n", me->name); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 369 | return -ENOEXEC; |
| 370 | } |
| 371 | |
Alan Modra | f749eda | 2006-04-24 22:11:51 +0930 | [diff] [blame] | 372 | /* If we don't have a .toc, just use .stubs. We need to set r2 |
| 373 | to some reasonable value in case the module calls out to |
| 374 | other functions via a stub, or if a function pointer escapes |
| 375 | the module by some means. */ |
| 376 | if (!me->arch.toc_section) |
| 377 | me->arch.toc_section = me->arch.stubs_section; |
| 378 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 379 | /* Override the stubs size */ |
| 380 | sechdrs[me->arch.stubs_section].sh_size = get_stubs_size(hdr, sechdrs); |
| 381 | return 0; |
| 382 | } |
| 383 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 384 | /* r2 is the TOC pointer: it actually points 0x8000 into the TOC (this |
| 385 | gives the value maximum span in an instruction which uses a signed |
| 386 | offset) */ |
Michael Ellerman | 136cd34 | 2016-03-03 15:26:54 +1100 | [diff] [blame] | 387 | static inline unsigned long my_r2(const Elf64_Shdr *sechdrs, struct module *me) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 388 | { |
| 389 | return sechdrs[me->arch.toc_section].sh_addr + 0x8000; |
| 390 | } |
| 391 | |
| 392 | /* Both low and high 16 bits are added as SIGNED additions, so if low |
| 393 | 16 bits has high bit set, high 16 bits must be adjusted. These |
| 394 | macros do that (stolen from binutils). */ |
| 395 | #define PPC_LO(v) ((v) & 0xffff) |
| 396 | #define PPC_HI(v) (((v) >> 16) & 0xffff) |
| 397 | #define PPC_HA(v) PPC_HI ((v) + 0x8000) |
| 398 | |
| 399 | /* Patch stub to reference function and correct r2 value. */ |
Michael Ellerman | 136cd34 | 2016-03-03 15:26:54 +1100 | [diff] [blame] | 400 | static inline int create_stub(const Elf64_Shdr *sechdrs, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 401 | struct ppc64_stub_entry *entry, |
Rusty Russell | 008d7a91 | 2014-03-19 10:42:22 +1030 | [diff] [blame] | 402 | unsigned long addr, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 403 | struct module *me) |
| 404 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 405 | long reladdr; |
| 406 | |
Anton Blanchard | 83775b8 | 2014-04-03 20:00:43 +1100 | [diff] [blame] | 407 | memcpy(entry->jump, ppc64_stub_insns, sizeof(ppc64_stub_insns)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 408 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 409 | /* Stub uses address relative to r2. */ |
| 410 | reladdr = (unsigned long)entry - my_r2(sechdrs, me); |
| 411 | if (reladdr > 0x7FFFFFFF || reladdr < -(0x80000000L)) { |
Anton Blanchard | c7d1f6a | 2014-09-17 14:39:35 +1000 | [diff] [blame] | 412 | pr_err("%s: Address %p of stub out of range of %p.\n", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 413 | me->name, (void *)reladdr, (void *)my_r2); |
| 414 | return 0; |
| 415 | } |
Anton Blanchard | c7d1f6a | 2014-09-17 14:39:35 +1000 | [diff] [blame] | 416 | pr_debug("Stub %p get data from reladdr %li\n", entry, reladdr); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 417 | |
Rusty Russell | 0e60e46 | 2014-03-18 17:35:28 +1030 | [diff] [blame] | 418 | entry->jump[0] |= PPC_HA(reladdr); |
| 419 | entry->jump[1] |= PPC_LO(reladdr); |
Rusty Russell | 008d7a91 | 2014-03-19 10:42:22 +1030 | [diff] [blame] | 420 | entry->funcdata = func_desc(addr); |
Michael Ellerman | f17c4e0 | 2016-03-03 15:26:55 +1100 | [diff] [blame] | 421 | entry->magic = STUB_MAGIC; |
| 422 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 423 | return 1; |
| 424 | } |
| 425 | |
Rusty Russell | 008d7a91 | 2014-03-19 10:42:22 +1030 | [diff] [blame] | 426 | /* Create stub to jump to function described in this OPD/ptr: we need the |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 427 | stub to set up the TOC ptr (r2) for the function. */ |
Michael Ellerman | 136cd34 | 2016-03-03 15:26:54 +1100 | [diff] [blame] | 428 | static unsigned long stub_for_addr(const Elf64_Shdr *sechdrs, |
Rusty Russell | 008d7a91 | 2014-03-19 10:42:22 +1030 | [diff] [blame] | 429 | unsigned long addr, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 430 | struct module *me) |
| 431 | { |
| 432 | struct ppc64_stub_entry *stubs; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 433 | unsigned int i, num_stubs; |
| 434 | |
| 435 | num_stubs = sechdrs[me->arch.stubs_section].sh_size / sizeof(*stubs); |
| 436 | |
| 437 | /* Find this stub, or if that fails, the next avail. entry */ |
| 438 | stubs = (void *)sechdrs[me->arch.stubs_section].sh_addr; |
Rusty Russell | 008d7a91 | 2014-03-19 10:42:22 +1030 | [diff] [blame] | 439 | for (i = 0; stub_func_addr(stubs[i].funcdata); i++) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 440 | BUG_ON(i >= num_stubs); |
| 441 | |
Rusty Russell | 008d7a91 | 2014-03-19 10:42:22 +1030 | [diff] [blame] | 442 | if (stub_func_addr(stubs[i].funcdata) == func_addr(addr)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 443 | return (unsigned long)&stubs[i]; |
| 444 | } |
| 445 | |
Rusty Russell | 008d7a91 | 2014-03-19 10:42:22 +1030 | [diff] [blame] | 446 | if (!create_stub(sechdrs, &stubs[i], addr, me)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 447 | return 0; |
| 448 | |
| 449 | return (unsigned long)&stubs[i]; |
| 450 | } |
| 451 | |
Torsten Duwe | 1530866 | 2016-03-03 15:26:59 +1100 | [diff] [blame] | 452 | #ifdef CC_USING_MPROFILE_KERNEL |
| 453 | static bool is_early_mcount_callsite(u32 *instruction) |
| 454 | { |
| 455 | /* |
| 456 | * Check if this is one of the -mprofile-kernel sequences. |
| 457 | */ |
| 458 | if (instruction[-1] == PPC_INST_STD_LR && |
| 459 | instruction[-2] == PPC_INST_MFLR) |
| 460 | return true; |
| 461 | |
| 462 | if (instruction[-1] == PPC_INST_MFLR) |
| 463 | return true; |
| 464 | |
| 465 | return false; |
| 466 | } |
| 467 | |
| 468 | /* |
| 469 | * In case of _mcount calls, do not save the current callee's TOC (in r2) into |
| 470 | * the original caller's stack frame. If we did we would clobber the saved TOC |
| 471 | * value of the original caller. |
| 472 | */ |
| 473 | static void squash_toc_save_inst(const char *name, unsigned long addr) |
| 474 | { |
| 475 | struct ppc64_stub_entry *stub = (struct ppc64_stub_entry *)addr; |
| 476 | |
| 477 | /* Only for calls to _mcount */ |
| 478 | if (strcmp("_mcount", name) != 0) |
| 479 | return; |
| 480 | |
| 481 | stub->jump[2] = PPC_INST_NOP; |
| 482 | } |
| 483 | #else |
| 484 | static void squash_toc_save_inst(const char *name, unsigned long addr) { } |
| 485 | |
| 486 | /* without -mprofile-kernel, mcount calls are never early */ |
| 487 | static bool is_early_mcount_callsite(u32 *instruction) |
| 488 | { |
| 489 | return false; |
| 490 | } |
| 491 | #endif |
| 492 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 493 | /* We expect a noop next: if it is, replace it with instruction to |
| 494 | restore r2. */ |
| 495 | static int restore_r2(u32 *instruction, struct module *me) |
| 496 | { |
Josh Poimboeuf | f6edf95 | 2017-11-16 11:45:37 -0600 | [diff] [blame] | 497 | u32 *prev_insn = instruction - 1; |
| 498 | |
| 499 | if (is_early_mcount_callsite(prev_insn)) |
| 500 | return 1; |
| 501 | |
| 502 | /* |
| 503 | * Make sure the branch isn't a sibling call. Sibling calls aren't |
| 504 | * "link" branches and they don't return, so they don't need the r2 |
| 505 | * restore afterwards. |
| 506 | */ |
| 507 | if (!instr_is_relative_link_branch(*prev_insn)) |
Michael Ellerman | 31278b1 | 2016-07-19 14:48:31 +1000 | [diff] [blame] | 508 | return 1; |
| 509 | |
Kumar Gala | 16c57b3 | 2009-02-10 20:10:44 +0000 | [diff] [blame] | 510 | if (*instruction != PPC_INST_NOP) { |
Anton Blanchard | c7d1f6a | 2014-09-17 14:39:35 +1000 | [diff] [blame] | 511 | pr_err("%s: Expect noop after relocate, got %08x\n", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 512 | me->name, *instruction); |
| 513 | return 0; |
| 514 | } |
Rusty Russell | d2fae54 | 2014-03-18 20:12:44 +1030 | [diff] [blame] | 515 | /* ld r2,R2_STACK_OFFSET(r1) */ |
Torsten Duwe | 1530866 | 2016-03-03 15:26:59 +1100 | [diff] [blame] | 516 | *instruction = PPC_INST_LD_TOC; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 517 | return 1; |
| 518 | } |
| 519 | |
| 520 | int apply_relocate_add(Elf64_Shdr *sechdrs, |
| 521 | const char *strtab, |
| 522 | unsigned int symindex, |
| 523 | unsigned int relsec, |
| 524 | struct module *me) |
| 525 | { |
| 526 | unsigned int i; |
| 527 | Elf64_Rela *rela = (void *)sechdrs[relsec].sh_addr; |
| 528 | Elf64_Sym *sym; |
| 529 | unsigned long *location; |
| 530 | unsigned long value; |
| 531 | |
Anton Blanchard | c7d1f6a | 2014-09-17 14:39:35 +1000 | [diff] [blame] | 532 | pr_debug("Applying ADD relocate section %u to %u\n", relsec, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 533 | sechdrs[relsec].sh_info); |
Rusty Russell | 4edebbe | 2014-03-18 19:59:26 +1030 | [diff] [blame] | 534 | |
| 535 | /* First time we're called, we can fix up .TOC. */ |
| 536 | if (!me->arch.toc_fixed) { |
| 537 | sym = find_dot_toc(sechdrs, strtab, symindex); |
| 538 | /* It's theoretically possible that a module doesn't want a |
| 539 | * .TOC. so don't fail it just for that. */ |
| 540 | if (sym) |
| 541 | sym->st_value = my_r2(sechdrs, me); |
| 542 | me->arch.toc_fixed = true; |
| 543 | } |
| 544 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 545 | for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rela); i++) { |
| 546 | /* This is where to make the change */ |
| 547 | location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr |
| 548 | + rela[i].r_offset; |
| 549 | /* This is the symbol it is referring to */ |
| 550 | sym = (Elf64_Sym *)sechdrs[symindex].sh_addr |
| 551 | + ELF64_R_SYM(rela[i].r_info); |
| 552 | |
Anton Blanchard | c7d1f6a | 2014-09-17 14:39:35 +1000 | [diff] [blame] | 553 | pr_debug("RELOC at %p: %li-type as %s (0x%lx) + %li\n", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 554 | location, (long)ELF64_R_TYPE(rela[i].r_info), |
| 555 | strtab + sym->st_name, (unsigned long)sym->st_value, |
| 556 | (long)rela[i].r_addend); |
| 557 | |
| 558 | /* `Everything is relative'. */ |
| 559 | value = sym->st_value + rela[i].r_addend; |
| 560 | |
| 561 | switch (ELF64_R_TYPE(rela[i].r_info)) { |
| 562 | case R_PPC64_ADDR32: |
| 563 | /* Simply set it */ |
| 564 | *(u32 *)location = value; |
| 565 | break; |
Emil Medve | eda09fb | 2007-11-14 03:24:04 +1100 | [diff] [blame] | 566 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 567 | case R_PPC64_ADDR64: |
| 568 | /* Simply set it */ |
| 569 | *(unsigned long *)location = value; |
| 570 | break; |
| 571 | |
| 572 | case R_PPC64_TOC: |
| 573 | *(unsigned long *)location = my_r2(sechdrs, me); |
| 574 | break; |
| 575 | |
Peter Bergner | 9149ccf | 2005-10-11 09:28:24 -0700 | [diff] [blame] | 576 | case R_PPC64_TOC16: |
Alan Modra | f749eda | 2006-04-24 22:11:51 +0930 | [diff] [blame] | 577 | /* Subtract TOC pointer */ |
Peter Bergner | 9149ccf | 2005-10-11 09:28:24 -0700 | [diff] [blame] | 578 | value -= my_r2(sechdrs, me); |
| 579 | if (value + 0x8000 > 0xffff) { |
Anton Blanchard | c7d1f6a | 2014-09-17 14:39:35 +1000 | [diff] [blame] | 580 | pr_err("%s: bad TOC16 relocation (0x%lx)\n", |
Peter Bergner | 9149ccf | 2005-10-11 09:28:24 -0700 | [diff] [blame] | 581 | me->name, value); |
| 582 | return -ENOEXEC; |
| 583 | } |
| 584 | *((uint16_t *) location) |
| 585 | = (*((uint16_t *) location) & ~0xffff) |
| 586 | | (value & 0xffff); |
| 587 | break; |
| 588 | |
Anton Blanchard | 1fbe9cf | 2012-11-26 17:41:08 +0000 | [diff] [blame] | 589 | case R_PPC64_TOC16_LO: |
| 590 | /* Subtract TOC pointer */ |
| 591 | value -= my_r2(sechdrs, me); |
| 592 | *((uint16_t *) location) |
| 593 | = (*((uint16_t *) location) & ~0xffff) |
| 594 | | (value & 0xffff); |
| 595 | break; |
| 596 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 597 | case R_PPC64_TOC16_DS: |
Alan Modra | f749eda | 2006-04-24 22:11:51 +0930 | [diff] [blame] | 598 | /* Subtract TOC pointer */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 599 | value -= my_r2(sechdrs, me); |
| 600 | if ((value & 3) != 0 || value + 0x8000 > 0xffff) { |
Anton Blanchard | c7d1f6a | 2014-09-17 14:39:35 +1000 | [diff] [blame] | 601 | pr_err("%s: bad TOC16_DS relocation (0x%lx)\n", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 602 | me->name, value); |
| 603 | return -ENOEXEC; |
| 604 | } |
| 605 | *((uint16_t *) location) |
| 606 | = (*((uint16_t *) location) & ~0xfffc) |
| 607 | | (value & 0xfffc); |
| 608 | break; |
| 609 | |
Anton Blanchard | 1fbe9cf | 2012-11-26 17:41:08 +0000 | [diff] [blame] | 610 | case R_PPC64_TOC16_LO_DS: |
| 611 | /* Subtract TOC pointer */ |
| 612 | value -= my_r2(sechdrs, me); |
| 613 | if ((value & 3) != 0) { |
Anton Blanchard | c7d1f6a | 2014-09-17 14:39:35 +1000 | [diff] [blame] | 614 | pr_err("%s: bad TOC16_LO_DS relocation (0x%lx)\n", |
Anton Blanchard | 1fbe9cf | 2012-11-26 17:41:08 +0000 | [diff] [blame] | 615 | me->name, value); |
| 616 | return -ENOEXEC; |
| 617 | } |
| 618 | *((uint16_t *) location) |
| 619 | = (*((uint16_t *) location) & ~0xfffc) |
| 620 | | (value & 0xfffc); |
| 621 | break; |
| 622 | |
| 623 | case R_PPC64_TOC16_HA: |
| 624 | /* Subtract TOC pointer */ |
| 625 | value -= my_r2(sechdrs, me); |
| 626 | value = ((value + 0x8000) >> 16); |
| 627 | *((uint16_t *) location) |
| 628 | = (*((uint16_t *) location) & ~0xffff) |
| 629 | | (value & 0xffff); |
| 630 | break; |
| 631 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 632 | case R_PPC_REL24: |
| 633 | /* FIXME: Handle weak symbols here --RR */ |
| 634 | if (sym->st_shndx == SHN_UNDEF) { |
| 635 | /* External: go via stub */ |
| 636 | value = stub_for_addr(sechdrs, value, me); |
| 637 | if (!value) |
| 638 | return -ENOENT; |
| 639 | if (!restore_r2((u32 *)location + 1, me)) |
| 640 | return -ENOEXEC; |
Torsten Duwe | 1530866 | 2016-03-03 15:26:59 +1100 | [diff] [blame] | 641 | |
| 642 | squash_toc_save_inst(strtab + sym->st_name, value); |
Rusty Russell | 008d7a91 | 2014-03-19 10:42:22 +1030 | [diff] [blame] | 643 | } else |
| 644 | value += local_entry_offset(sym); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 645 | |
| 646 | /* Convert value to relative */ |
| 647 | value -= (unsigned long)location; |
| 648 | if (value + 0x2000000 > 0x3ffffff || (value & 3) != 0){ |
Anton Blanchard | c7d1f6a | 2014-09-17 14:39:35 +1000 | [diff] [blame] | 649 | pr_err("%s: REL24 %li out of range!\n", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 650 | me->name, (long int)value); |
| 651 | return -ENOEXEC; |
| 652 | } |
| 653 | |
| 654 | /* Only replace bits 2 through 26 */ |
Emil Medve | eda09fb | 2007-11-14 03:24:04 +1100 | [diff] [blame] | 655 | *(uint32_t *)location |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 656 | = (*(uint32_t *)location & ~0x03fffffc) |
| 657 | | (value & 0x03fffffc); |
| 658 | break; |
| 659 | |
Benjamin Herrenschmidt | 21c4ff8 | 2006-10-20 11:47:19 +1000 | [diff] [blame] | 660 | case R_PPC64_REL64: |
| 661 | /* 64 bits relative (used by features fixups) */ |
| 662 | *location = value - (unsigned long)location; |
| 663 | break; |
| 664 | |
Rusty Russell | d247da0 | 2014-03-18 17:36:28 +1030 | [diff] [blame] | 665 | case R_PPC64_TOCSAVE: |
| 666 | /* |
| 667 | * Marker reloc indicates we don't have to save r2. |
| 668 | * That would only save us one instruction, so ignore |
| 669 | * it. |
| 670 | */ |
| 671 | break; |
| 672 | |
Ulrich Weigand | a61674b | 2016-01-12 23:14:23 +1100 | [diff] [blame] | 673 | case R_PPC64_ENTRY: |
| 674 | /* |
| 675 | * Optimize ELFv2 large code model entry point if |
| 676 | * the TOC is within 2GB range of current location. |
| 677 | */ |
| 678 | value = my_r2(sechdrs, me) - (unsigned long)location; |
| 679 | if (value + 0x80008000 > 0xffffffff) |
| 680 | break; |
| 681 | /* |
| 682 | * Check for the large code model prolog sequence: |
| 683 | * ld r2, ...(r12) |
| 684 | * add r2, r2, r12 |
| 685 | */ |
| 686 | if ((((uint32_t *)location)[0] & ~0xfffc) |
| 687 | != 0xe84c0000) |
| 688 | break; |
| 689 | if (((uint32_t *)location)[1] != 0x7c426214) |
| 690 | break; |
| 691 | /* |
| 692 | * If found, replace it with: |
| 693 | * addis r2, r12, (.TOC.-func)@ha |
| 694 | * addi r2, r12, (.TOC.-func)@l |
| 695 | */ |
| 696 | ((uint32_t *)location)[0] = 0x3c4c0000 + PPC_HA(value); |
| 697 | ((uint32_t *)location)[1] = 0x38420000 + PPC_LO(value); |
| 698 | break; |
| 699 | |
Rusty Russell | 0906584 | 2014-03-18 19:59:27 +1030 | [diff] [blame] | 700 | case R_PPC64_REL16_HA: |
| 701 | /* Subtract location pointer */ |
| 702 | value -= (unsigned long)location; |
| 703 | value = ((value + 0x8000) >> 16); |
| 704 | *((uint16_t *) location) |
| 705 | = (*((uint16_t *) location) & ~0xffff) |
| 706 | | (value & 0xffff); |
| 707 | break; |
| 708 | |
| 709 | case R_PPC64_REL16_LO: |
| 710 | /* Subtract location pointer */ |
| 711 | value -= (unsigned long)location; |
| 712 | *((uint16_t *) location) |
| 713 | = (*((uint16_t *) location) & ~0xffff) |
| 714 | | (value & 0xffff); |
| 715 | break; |
| 716 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 717 | default: |
Anton Blanchard | c7d1f6a | 2014-09-17 14:39:35 +1000 | [diff] [blame] | 718 | pr_err("%s: Unknown ADD relocation: %lu\n", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 719 | me->name, |
| 720 | (unsigned long)ELF64_R_TYPE(rela[i].r_info)); |
| 721 | return -ENOEXEC; |
| 722 | } |
| 723 | } |
| 724 | |
Michael Ellerman | 136cd34 | 2016-03-03 15:26:54 +1100 | [diff] [blame] | 725 | return 0; |
| 726 | } |
| 727 | |
Steven Rostedt | f48cb8b | 2008-11-14 20:47:03 -0800 | [diff] [blame] | 728 | #ifdef CONFIG_DYNAMIC_FTRACE |
Michael Ellerman | 336a7b5 | 2016-03-03 15:26:56 +1100 | [diff] [blame] | 729 | |
| 730 | #ifdef CC_USING_MPROFILE_KERNEL |
| 731 | |
| 732 | #define PACATOC offsetof(struct paca_struct, kernel_toc) |
| 733 | |
| 734 | /* |
| 735 | * For mprofile-kernel we use a special stub for ftrace_caller() because we |
| 736 | * can't rely on r2 containing this module's TOC when we enter the stub. |
| 737 | * |
| 738 | * That can happen if the function calling us didn't need to use the toc. In |
| 739 | * that case it won't have setup r2, and the r2 value will be either the |
| 740 | * kernel's toc, or possibly another modules toc. |
| 741 | * |
| 742 | * To deal with that this stub uses the kernel toc, which is always accessible |
| 743 | * via the paca (in r13). The target (ftrace_caller()) is responsible for |
| 744 | * saving and restoring the toc before returning. |
| 745 | */ |
| 746 | static unsigned long create_ftrace_stub(const Elf64_Shdr *sechdrs, struct module *me) |
| 747 | { |
| 748 | struct ppc64_stub_entry *entry; |
| 749 | unsigned int i, num_stubs; |
| 750 | static u32 stub_insns[] = { |
| 751 | 0xe98d0000 | PACATOC, /* ld r12,PACATOC(r13) */ |
| 752 | 0x3d8c0000, /* addis r12,r12,<high> */ |
| 753 | 0x398c0000, /* addi r12,r12,<low> */ |
| 754 | 0x7d8903a6, /* mtctr r12 */ |
| 755 | 0x4e800420, /* bctr */ |
| 756 | }; |
| 757 | long reladdr; |
| 758 | |
| 759 | num_stubs = sechdrs[me->arch.stubs_section].sh_size / sizeof(*entry); |
| 760 | |
| 761 | /* Find the next available stub entry */ |
| 762 | entry = (void *)sechdrs[me->arch.stubs_section].sh_addr; |
| 763 | for (i = 0; i < num_stubs && stub_func_addr(entry->funcdata); i++, entry++); |
| 764 | |
| 765 | if (i >= num_stubs) { |
| 766 | pr_err("%s: Unable to find a free slot for ftrace stub.\n", me->name); |
| 767 | return 0; |
| 768 | } |
| 769 | |
| 770 | memcpy(entry->jump, stub_insns, sizeof(stub_insns)); |
| 771 | |
| 772 | /* Stub uses address relative to kernel toc (from the paca) */ |
| 773 | reladdr = (unsigned long)ftrace_caller - kernel_toc_addr(); |
| 774 | if (reladdr > 0x7FFFFFFF || reladdr < -(0x80000000L)) { |
| 775 | pr_err("%s: Address of ftrace_caller out of range of kernel_toc.\n", me->name); |
| 776 | return 0; |
| 777 | } |
| 778 | |
| 779 | entry->jump[1] |= PPC_HA(reladdr); |
| 780 | entry->jump[2] |= PPC_LO(reladdr); |
| 781 | |
| 782 | /* Eventhough we don't use funcdata in the stub, it's needed elsewhere. */ |
| 783 | entry->funcdata = func_desc((unsigned long)ftrace_caller); |
| 784 | entry->magic = STUB_MAGIC; |
| 785 | |
| 786 | return (unsigned long)entry; |
| 787 | } |
| 788 | #else |
| 789 | static unsigned long create_ftrace_stub(const Elf64_Shdr *sechdrs, struct module *me) |
| 790 | { |
| 791 | return stub_for_addr(sechdrs, (unsigned long)ftrace_caller, me); |
| 792 | } |
Steven Rostedt | f48cb8b | 2008-11-14 20:47:03 -0800 | [diff] [blame] | 793 | #endif |
| 794 | |
Michael Ellerman | 136cd34 | 2016-03-03 15:26:54 +1100 | [diff] [blame] | 795 | int module_finalize_ftrace(struct module *mod, const Elf_Shdr *sechdrs) |
| 796 | { |
| 797 | mod->arch.toc = my_r2(sechdrs, mod); |
Michael Ellerman | 336a7b5 | 2016-03-03 15:26:56 +1100 | [diff] [blame] | 798 | mod->arch.tramp = create_ftrace_stub(sechdrs, mod); |
Michael Ellerman | 136cd34 | 2016-03-03 15:26:54 +1100 | [diff] [blame] | 799 | |
| 800 | if (!mod->arch.tramp) |
| 801 | return -ENOENT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 802 | |
| 803 | return 0; |
| 804 | } |
Michael Ellerman | 136cd34 | 2016-03-03 15:26:54 +1100 | [diff] [blame] | 805 | #endif |