arch/mips/kernel/vpe.c

/* [<][>][^][v][top][bottom][index][help] */
This source file includes following definitions.
get_vpe
get_tc
alloc_vpe
alloc_tc
release_vpe
alloc_progmem
release_progmem
get_offset
layout_sections
apply_r_mips_none
apply_r_mips_gprel16
apply_r_mips_pc16
apply_r_mips_32
apply_r_mips_26
apply_r_mips_hi16
apply_r_mips_lo16
apply_relocations
save_gp_address
simplify_symbols
dump_elfsymbols
find_vpe_symbols
vpe_elfload
getcwd
vpe_open
vpe_release
vpe_write
vpe_get_shared
vpe_notify
vpe_getcwd
   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * Copyright (C) 2004, 2005 MIPS Technologies, Inc.  All rights reserved.
   7  * Copyright (C) 2013 Imagination Technologies Ltd.
   8  *
   9  * VPE spport module for loading a MIPS SP program into VPE1. The SP
  10  * environment is rather simple since there are no TLBs. It needs
  11  * to be relocatable (or partiall linked). Initialize your stack in
  12  * the startup-code. The loader looks for the symbol __start and sets
  13  * up the execution to resume from there. To load and run, simply do
  14  * a cat SP 'binary' to the /dev/vpe1 device.
  15  */
  16 #include <linux/kernel.h>
  17 #include <linux/device.h>
  18 #include <linux/fs.h>
  19 #include <linux/init.h>
  20 #include <linux/slab.h>
  21 #include <linux/list.h>
  22 #include <linux/vmalloc.h>
  23 #include <linux/elf.h>
  24 #include <linux/seq_file.h>
  25 #include <linux/syscalls.h>
  26 #include <linux/moduleloader.h>
  27 #include <linux/interrupt.h>
  28 #include <linux/poll.h>
  29 #include <linux/memblock.h>
  30 #include <asm/mipsregs.h>
  31 #include <asm/mipsmtregs.h>
  32 #include <asm/cacheflush.h>
  33 #include <linux/atomic.h>
  34 #include <asm/mips_mt.h>
  35 #include <asm/processor.h>
  36 #include <asm/vpe.h>
  37 
  38 #ifndef ARCH_SHF_SMALL
  39 #define ARCH_SHF_SMALL 0
  40 #endif
  41 
  42 /* If this is set, the section belongs in the init part of the module */
  43 #define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
  44 
  45 struct vpe_control vpecontrol = {
  46         .vpe_list_lock  = __SPIN_LOCK_UNLOCKED(vpe_list_lock),
  47         .vpe_list       = LIST_HEAD_INIT(vpecontrol.vpe_list),
  48         .tc_list_lock   = __SPIN_LOCK_UNLOCKED(tc_list_lock),
  49         .tc_list        = LIST_HEAD_INIT(vpecontrol.tc_list)
  50 };
  51 
  52 /* get the vpe associated with this minor */
  53 struct vpe *get_vpe(int minor)
  54 {
  55         struct vpe *res, *v;
  56 
  57         if (!cpu_has_mipsmt)
  58                 return NULL;
  59 
  60         res = NULL;
  61         spin_lock(&vpecontrol.vpe_list_lock);
  62         list_for_each_entry(v, &vpecontrol.vpe_list, list) {
  63                 if (v->minor == VPE_MODULE_MINOR) {
  64                         res = v;
  65                         break;
  66                 }
  67         }
  68         spin_unlock(&vpecontrol.vpe_list_lock);
  69 
  70         return res;
  71 }
  72 
  73 /* get the vpe associated with this minor */
  74 struct tc *get_tc(int index)
  75 {
  76         struct tc *res, *t;
  77 
  78         res = NULL;
  79         spin_lock(&vpecontrol.tc_list_lock);
  80         list_for_each_entry(t, &vpecontrol.tc_list, list) {
  81                 if (t->index == index) {
  82                         res = t;
  83                         break;
  84                 }
  85         }
  86         spin_unlock(&vpecontrol.tc_list_lock);
  87 
  88         return res;
  89 }
  90 
  91 /* allocate a vpe and associate it with this minor (or index) */
  92 struct vpe *alloc_vpe(int minor)
  93 {
  94         struct vpe *v;
  95 
  96         v = kzalloc(sizeof(struct vpe), GFP_KERNEL);
  97         if (v == NULL)
  98                 goto out;
  99 
 100         INIT_LIST_HEAD(&v->tc);
 101         spin_lock(&vpecontrol.vpe_list_lock);
 102         list_add_tail(&v->list, &vpecontrol.vpe_list);
 103         spin_unlock(&vpecontrol.vpe_list_lock);
 104 
 105         INIT_LIST_HEAD(&v->notify);
 106         v->minor = VPE_MODULE_MINOR;
 107 
 108 out:
 109         return v;
 110 }
 111 
 112 /* allocate a tc. At startup only tc0 is running, all other can be halted. */
 113 struct tc *alloc_tc(int index)
 114 {
 115         struct tc *tc;
 116 
 117         tc = kzalloc(sizeof(struct tc), GFP_KERNEL);
 118         if (tc == NULL)
 119                 goto out;
 120 
 121         INIT_LIST_HEAD(&tc->tc);
 122         tc->index = index;
 123 
 124         spin_lock(&vpecontrol.tc_list_lock);
 125         list_add_tail(&tc->list, &vpecontrol.tc_list);
 126         spin_unlock(&vpecontrol.tc_list_lock);
 127 
 128 out:
 129         return tc;
 130 }
 131 
 132 /* clean up and free everything */
 133 void release_vpe(struct vpe *v)
 134 {
 135         list_del(&v->list);
 136         if (v->load_addr)
 137                 release_progmem(v->load_addr);
 138         kfree(v);
 139 }
 140 
 141 /* Find some VPE program space */
 142 void *alloc_progmem(unsigned long len)
 143 {
 144         void *addr;
 145 
 146 #ifdef CONFIG_MIPS_VPE_LOADER_TOM
 147         /*
 148          * This means you must tell Linux to use less memory than you
 149          * physically have, for example by passing a mem= boot argument.
 150          */
 151         addr = pfn_to_kaddr(max_low_pfn);
 152         memset(addr, 0, len);
 153 #else
 154         /* simple grab some mem for now */
 155         addr = kzalloc(len, GFP_KERNEL);
 156 #endif
 157 
 158         return addr;
 159 }
 160 
 161 void release_progmem(void *ptr)
 162 {
 163 #ifndef CONFIG_MIPS_VPE_LOADER_TOM
 164         kfree(ptr);
 165 #endif
 166 }
 167 
 168 /* Update size with this section: return offset. */
 169 static long get_offset(unsigned long *size, Elf_Shdr *sechdr)
 170 {
 171         long ret;
 172 
 173         ret = ALIGN(*size, sechdr->sh_addralign ? : 1);
 174         *size = ret + sechdr->sh_size;
 175         return ret;
 176 }
 177 
 178 /* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
 179    might -- code, read-only data, read-write data, small data.  Tally
 180    sizes, and place the offsets into sh_entsize fields: high bit means it
 181    belongs in init. */
 182 static void layout_sections(struct module *mod, const Elf_Ehdr *hdr,
 183                             Elf_Shdr *sechdrs, const char *secstrings)
 184 {
 185         static unsigned long const masks[][2] = {
 186                 /* NOTE: all executable code must be the first section
 187                  * in this array; otherwise modify the text_size
 188                  * finder in the two loops below */
 189                 {SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL},
 190                 {SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL},
 191                 {SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL},
 192                 {ARCH_SHF_SMALL | SHF_ALLOC, 0}
 193         };
 194         unsigned int m, i;
 195 
 196         for (i = 0; i < hdr->e_shnum; i++)
 197                 sechdrs[i].sh_entsize = ~0UL;
 198 
 199         for (m = 0; m < ARRAY_SIZE(masks); ++m) {
 200                 for (i = 0; i < hdr->e_shnum; ++i) {
 201                         Elf_Shdr *s = &sechdrs[i];
 202 
 203                         if ((s->sh_flags & masks[m][0]) != masks[m][0]
 204                             || (s->sh_flags & masks[m][1])
 205                             || s->sh_entsize != ~0UL)
 206                                 continue;
 207                         s->sh_entsize =
 208                                 get_offset((unsigned long *)&mod->core_layout.size, s);
 209                 }
 210 
 211                 if (m == 0)
 212                         mod->core_layout.text_size = mod->core_layout.size;
 213 
 214         }
 215 }
 216 
 217 /* from module-elf32.c, but subverted a little */
 218 
 219 struct mips_hi16 {
 220         struct mips_hi16 *next;
 221         Elf32_Addr *addr;
 222         Elf32_Addr value;
 223 };
 224 
 225 static struct mips_hi16 *mips_hi16_list;
 226 static unsigned int gp_offs, gp_addr;
 227 
 228 static int apply_r_mips_none(struct module *me, uint32_t *location,
 229                              Elf32_Addr v)
 230 {
 231         return 0;
 232 }
 233 
 234 static int apply_r_mips_gprel16(struct module *me, uint32_t *location,
 235                                 Elf32_Addr v)
 236 {
 237         int rel;
 238 
 239         if (!(*location & 0xffff)) {
 240                 rel = (int)v - gp_addr;
 241         } else {
 242                 /* .sbss + gp(relative) + offset */
 243                 /* kludge! */
 244                 rel =  (int)(short)((int)v + gp_offs +
 245                                     (int)(short)(*location & 0xffff) - gp_addr);
 246         }
 247 
 248         if ((rel > 32768) || (rel < -32768)) {
 249                 pr_debug("VPE loader: apply_r_mips_gprel16: relative address 0x%x out of range of gp register\n",
 250                          rel);
 251                 return -ENOEXEC;
 252         }
 253 
 254         *location = (*location & 0xffff0000) | (rel & 0xffff);
 255 
 256         return 0;
 257 }
 258 
 259 static int apply_r_mips_pc16(struct module *me, uint32_t *location,
 260                              Elf32_Addr v)
 261 {
 262         int rel;
 263         rel = (((unsigned int)v - (unsigned int)location));
 264         rel >>= 2; /* because the offset is in _instructions_ not bytes. */
 265         rel -= 1;  /* and one instruction less due to the branch delay slot. */
 266 
 267         if ((rel > 32768) || (rel < -32768)) {
 268                 pr_debug("VPE loader: apply_r_mips_pc16: relative address out of range 0x%x\n",
 269                          rel);
 270                 return -ENOEXEC;
 271         }
 272 
 273         *location = (*location & 0xffff0000) | (rel & 0xffff);
 274 
 275         return 0;
 276 }
 277 
 278 static int apply_r_mips_32(struct module *me, uint32_t *location,
 279                            Elf32_Addr v)
 280 {
 281         *location += v;
 282 
 283         return 0;
 284 }
 285 
 286 static int apply_r_mips_26(struct module *me, uint32_t *location,
 287                            Elf32_Addr v)
 288 {
 289         if (v % 4) {
 290                 pr_debug("VPE loader: apply_r_mips_26: unaligned relocation\n");
 291                 return -ENOEXEC;
 292         }
 293 
 294 /*
 295  * Not desperately convinced this is a good check of an overflow condition
 296  * anyway. But it gets in the way of handling undefined weak symbols which
 297  * we want to set to zero.
 298  * if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) {
 299  * printk(KERN_ERR
 300  * "module %s: relocation overflow\n",
 301  * me->name);
 302  * return -ENOEXEC;
 303  * }
 304  */
 305 
 306         *location = (*location & ~0x03ffffff) |
 307                 ((*location + (v >> 2)) & 0x03ffffff);
 308         return 0;
 309 }
 310 
 311 static int apply_r_mips_hi16(struct module *me, uint32_t *location,
 312                              Elf32_Addr v)
 313 {
 314         struct mips_hi16 *n;
 315 
 316         /*
 317          * We cannot relocate this one now because we don't know the value of
 318          * the carry we need to add.  Save the information, and let LO16 do the
 319          * actual relocation.
 320          */
 321         n = kmalloc(sizeof(*n), GFP_KERNEL);
 322         if (!n)
 323                 return -ENOMEM;
 324 
 325         n->addr = location;
 326         n->value = v;
 327         n->next = mips_hi16_list;
 328         mips_hi16_list = n;
 329 
 330         return 0;
 331 }
 332 
 333 static int apply_r_mips_lo16(struct module *me, uint32_t *location,
 334                              Elf32_Addr v)
 335 {
 336         unsigned long insnlo = *location;
 337         Elf32_Addr val, vallo;
 338         struct mips_hi16 *l, *next;
 339 
 340         /* Sign extend the addend we extract from the lo insn.  */
 341         vallo = ((insnlo & 0xffff) ^ 0x8000) - 0x8000;
 342 
 343         if (mips_hi16_list != NULL) {
 344 
 345                 l = mips_hi16_list;
 346                 while (l != NULL) {
 347                         unsigned long insn;
 348 
 349                         /*
 350                          * The value for the HI16 had best be the same.
 351                          */
 352                         if (v != l->value) {
 353                                 pr_debug("VPE loader: apply_r_mips_lo16/hi16: inconsistent value information\n");
 354                                 goto out_free;
 355                         }
 356 
 357                         /*
 358                          * Do the HI16 relocation.  Note that we actually don't
 359                          * need to know anything about the LO16 itself, except
 360                          * where to find the low 16 bits of the addend needed
 361                          * by the LO16.
 362                          */
 363                         insn = *l->addr;
 364                         val = ((insn & 0xffff) << 16) + vallo;
 365                         val += v;
 366 
 367                         /*
 368                          * Account for the sign extension that will happen in
 369                          * the low bits.
 370                          */
 371                         val = ((val >> 16) + ((val & 0x8000) != 0)) & 0xffff;
 372 
 373                         insn = (insn & ~0xffff) | val;
 374                         *l->addr = insn;
 375 
 376                         next = l->next;
 377                         kfree(l);
 378                         l = next;
 379                 }
 380 
 381                 mips_hi16_list = NULL;
 382         }
 383 
 384         /*
 385          * Ok, we're done with the HI16 relocs.  Now deal with the LO16.
 386          */
 387         val = v + vallo;
 388         insnlo = (insnlo & ~0xffff) | (val & 0xffff);
 389         *location = insnlo;
 390 
 391         return 0;
 392 
 393 out_free:
 394         while (l != NULL) {
 395                 next = l->next;
 396                 kfree(l);
 397                 l = next;
 398         }
 399         mips_hi16_list = NULL;
 400 
 401         return -ENOEXEC;
 402 }
 403 
 404 static int (*reloc_handlers[]) (struct module *me, uint32_t *location,
 405                                 Elf32_Addr v) = {
 406         [R_MIPS_NONE]   = apply_r_mips_none,
 407         [R_MIPS_32]     = apply_r_mips_32,
 408         [R_MIPS_26]     = apply_r_mips_26,
 409         [R_MIPS_HI16]   = apply_r_mips_hi16,
 410         [R_MIPS_LO16]   = apply_r_mips_lo16,
 411         [R_MIPS_GPREL16] = apply_r_mips_gprel16,
 412         [R_MIPS_PC16] = apply_r_mips_pc16
 413 };
 414 
 415 static char *rstrs[] = {
 416         [R_MIPS_NONE]   = "MIPS_NONE",
 417         [R_MIPS_32]     = "MIPS_32",
 418         [R_MIPS_26]     = "MIPS_26",
 419         [R_MIPS_HI16]   = "MIPS_HI16",
 420         [R_MIPS_LO16]   = "MIPS_LO16",
 421         [R_MIPS_GPREL16] = "MIPS_GPREL16",
 422         [R_MIPS_PC16] = "MIPS_PC16"
 423 };
 424 
 425 static int apply_relocations(Elf32_Shdr *sechdrs,
 426                       const char *strtab,
 427                       unsigned int symindex,
 428                       unsigned int relsec,
 429                       struct module *me)
 430 {
 431         Elf32_Rel *rel = (void *) sechdrs[relsec].sh_addr;
 432         Elf32_Sym *sym;
 433         uint32_t *location;
 434         unsigned int i;
 435         Elf32_Addr v;
 436         int res;
 437 
 438         for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
 439                 Elf32_Word r_info = rel[i].r_info;
 440 
 441                 /* This is where to make the change */
 442                 location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
 443                         + rel[i].r_offset;
 444                 /* This is the symbol it is referring to */
 445                 sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
 446                         + ELF32_R_SYM(r_info);
 447 
 448                 if (!sym->st_value) {
 449                         pr_debug("%s: undefined weak symbol %s\n",
 450                                  me->name, strtab + sym->st_name);
 451                         /* just print the warning, dont barf */
 452                 }
 453 
 454                 v = sym->st_value;
 455 
 456                 res = reloc_handlers[ELF32_R_TYPE(r_info)](me, location, v);
 457                 if (res) {
 458                         char *r = rstrs[ELF32_R_TYPE(r_info)];
 459                         pr_warn("VPE loader: .text+0x%x relocation type %s for symbol \"%s\" failed\n",
 460                                 rel[i].r_offset, r ? r : "UNKNOWN",
 461                                 strtab + sym->st_name);
 462                         return res;
 463                 }
 464         }
 465 
 466         return 0;
 467 }
 468 
 469 static inline void save_gp_address(unsigned int secbase, unsigned int rel)
 470 {
 471         gp_addr = secbase + rel;
 472         gp_offs = gp_addr - (secbase & 0xffff0000);
 473 }
 474 /* end module-elf32.c */
 475 
 476 /* Change all symbols so that sh_value encodes the pointer directly. */
 477 static void simplify_symbols(Elf_Shdr *sechdrs,
 478                             unsigned int symindex,
 479                             const char *strtab,
 480                             const char *secstrings,
 481                             unsigned int nsecs, struct module *mod)
 482 {
 483         Elf_Sym *sym = (void *)sechdrs[symindex].sh_addr;
 484         unsigned long secbase, bssbase = 0;
 485         unsigned int i, n = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
 486         int size;
 487 
 488         /* find the .bss section for COMMON symbols */
 489         for (i = 0; i < nsecs; i++) {
 490                 if (strncmp(secstrings + sechdrs[i].sh_name, ".bss", 4) == 0) {
 491                         bssbase = sechdrs[i].sh_addr;
 492                         break;
 493                 }
 494         }
 495 
 496         for (i = 1; i < n; i++) {
 497                 switch (sym[i].st_shndx) {
 498                 case SHN_COMMON:
 499                         /* Allocate space for the symbol in the .bss section.
 500                            st_value is currently size.
 501                            We want it to have the address of the symbol. */
 502 
 503                         size = sym[i].st_value;
 504                         sym[i].st_value = bssbase;
 505 
 506                         bssbase += size;
 507                         break;
 508 
 509                 case SHN_ABS:
 510                         /* Don't need to do anything */
 511                         break;
 512 
 513                 case SHN_UNDEF:
 514                         /* ret = -ENOENT; */
 515                         break;
 516 
 517                 case SHN_MIPS_SCOMMON:
 518                         pr_debug("simplify_symbols: ignoring SHN_MIPS_SCOMMON symbol <%s> st_shndx %d\n",
 519                                  strtab + sym[i].st_name, sym[i].st_shndx);
 520                         /* .sbss section */
 521                         break;
 522 
 523                 default:
 524                         secbase = sechdrs[sym[i].st_shndx].sh_addr;
 525 
 526                         if (strncmp(strtab + sym[i].st_name, "_gp", 3) == 0)
 527                                 save_gp_address(secbase, sym[i].st_value);
 528 
 529                         sym[i].st_value += secbase;
 530                         break;
 531                 }
 532         }
 533 }
 534 
 535 #ifdef DEBUG_ELFLOADER
 536 static void dump_elfsymbols(Elf_Shdr *sechdrs, unsigned int symindex,
 537                             const char *strtab, struct module *mod)
 538 {
 539         Elf_Sym *sym = (void *)sechdrs[symindex].sh_addr;
 540         unsigned int i, n = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
 541 
 542         pr_debug("dump_elfsymbols: n %d\n", n);
 543         for (i = 1; i < n; i++) {
 544                 pr_debug(" i %d name <%s> 0x%x\n", i, strtab + sym[i].st_name,
 545                          sym[i].st_value);
 546         }
 547 }
 548 #endif
 549 
 550 static int find_vpe_symbols(struct vpe *v, Elf_Shdr *sechdrs,
 551                                       unsigned int symindex, const char *strtab,
 552                                       struct module *mod)
 553 {
 554         Elf_Sym *sym = (void *)sechdrs[symindex].sh_addr;
 555         unsigned int i, n = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
 556 
 557         for (i = 1; i < n; i++) {
 558                 if (strcmp(strtab + sym[i].st_name, "__start") == 0)
 559                         v->__start = sym[i].st_value;
 560 
 561                 if (strcmp(strtab + sym[i].st_name, "vpe_shared") == 0)
 562                         v->shared_ptr = (void *)sym[i].st_value;
 563         }
 564 
 565         if ((v->__start == 0) || (v->shared_ptr == NULL))
 566                 return -1;
 567 
 568         return 0;
 569 }
 570 
 571 /*
 572  * Allocates a VPE with some program code space(the load address), copies the
 573  * contents of the program (p)buffer performing relocatations/etc, free's it
 574  * when finished.
 575  */
 576 static int vpe_elfload(struct vpe *v)
 577 {
 578         Elf_Ehdr *hdr;
 579         Elf_Shdr *sechdrs;
 580         long err = 0;
 581         char *secstrings, *strtab = NULL;
 582         unsigned int len, i, symindex = 0, strindex = 0, relocate = 0;
 583         struct module mod; /* so we can re-use the relocations code */
 584 
 585         memset(&mod, 0, sizeof(struct module));
 586         strcpy(mod.name, "VPE loader");
 587 
 588         hdr = (Elf_Ehdr *) v->pbuffer;
 589         len = v->plen;
 590 
 591         /* Sanity checks against insmoding binaries or wrong arch,
 592            weird elf version */
 593         if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0
 594             || (hdr->e_type != ET_REL && hdr->e_type != ET_EXEC)
 595             || !elf_check_arch(hdr)
 596             || hdr->e_shentsize != sizeof(*sechdrs)) {
 597                 pr_warn("VPE loader: program wrong arch or weird elf version\n");
 598 
 599                 return -ENOEXEC;
 600         }
 601 
 602         if (hdr->e_type == ET_REL)
 603                 relocate = 1;
 604 
 605         if (len < hdr->e_shoff + hdr->e_shnum * sizeof(Elf_Shdr)) {
 606                 pr_err("VPE loader: program length %u truncated\n", len);
 607 
 608                 return -ENOEXEC;
 609         }
 610 
 611         /* Convenience variables */
 612         sechdrs = (void *)hdr + hdr->e_shoff;
 613         secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
 614         sechdrs[0].sh_addr = 0;
 615 
 616         /* And these should exist, but gcc whinges if we don't init them */
 617         symindex = strindex = 0;
 618 
 619         if (relocate) {
 620                 for (i = 1; i < hdr->e_shnum; i++) {
 621                         if ((sechdrs[i].sh_type != SHT_NOBITS) &&
 622                             (len < sechdrs[i].sh_offset + sechdrs[i].sh_size)) {
 623                                 pr_err("VPE program length %u truncated\n",
 624                                        len);
 625                                 return -ENOEXEC;
 626                         }
 627 
 628                         /* Mark all sections sh_addr with their address in the
 629                            temporary image. */
 630                         sechdrs[i].sh_addr = (size_t) hdr +
 631                                 sechdrs[i].sh_offset;
 632 
 633                         /* Internal symbols and strings. */
 634                         if (sechdrs[i].sh_type == SHT_SYMTAB) {
 635                                 symindex = i;
 636                                 strindex = sechdrs[i].sh_link;
 637                                 strtab = (char *)hdr +
 638                                         sechdrs[strindex].sh_offset;
 639                         }
 640                 }
 641                 layout_sections(&mod, hdr, sechdrs, secstrings);
 642         }
 643 
 644         v->load_addr = alloc_progmem(mod.core_layout.size);
 645         if (!v->load_addr)
 646                 return -ENOMEM;
 647 
 648         pr_info("VPE loader: loading to %p\n", v->load_addr);
 649 
 650         if (relocate) {
 651                 for (i = 0; i < hdr->e_shnum; i++) {
 652                         void *dest;
 653 
 654                         if (!(sechdrs[i].sh_flags & SHF_ALLOC))
 655                                 continue;
 656 
 657                         dest = v->load_addr + sechdrs[i].sh_entsize;
 658 
 659                         if (sechdrs[i].sh_type != SHT_NOBITS)
 660                                 memcpy(dest, (void *)sechdrs[i].sh_addr,
 661                                        sechdrs[i].sh_size);
 662                         /* Update sh_addr to point to copy in image. */
 663                         sechdrs[i].sh_addr = (unsigned long)dest;
 664 
 665                         pr_debug(" section sh_name %s sh_addr 0x%x\n",
 666                                  secstrings + sechdrs[i].sh_name,
 667                                  sechdrs[i].sh_addr);
 668                 }
 669 
 670                 /* Fix up syms, so that st_value is a pointer to location. */
 671                 simplify_symbols(sechdrs, symindex, strtab, secstrings,
 672                                  hdr->e_shnum, &mod);
 673 
 674                 /* Now do relocations. */
 675                 for (i = 1; i < hdr->e_shnum; i++) {
 676                         const char *strtab = (char *)sechdrs[strindex].sh_addr;
 677                         unsigned int info = sechdrs[i].sh_info;
 678 
 679                         /* Not a valid relocation section? */
 680                         if (info >= hdr->e_shnum)
 681                                 continue;
 682 
 683                         /* Don't bother with non-allocated sections */
 684                         if (!(sechdrs[info].sh_flags & SHF_ALLOC))
 685                                 continue;
 686 
 687                         if (sechdrs[i].sh_type == SHT_REL)
 688                                 err = apply_relocations(sechdrs, strtab,
 689                                                         symindex, i, &mod);
 690                         else if (sechdrs[i].sh_type == SHT_RELA)
 691                                 err = apply_relocate_add(sechdrs, strtab,
 692                                                          symindex, i, &mod);
 693                         if (err < 0)
 694                                 return err;
 695 
 696                 }
 697         } else {
 698                 struct elf_phdr *phdr = (struct elf_phdr *)
 699                                                 ((char *)hdr + hdr->e_phoff);
 700 
 701                 for (i = 0; i < hdr->e_phnum; i++) {
 702                         if (phdr->p_type == PT_LOAD) {
 703                                 memcpy((void *)phdr->p_paddr,
 704                                        (char *)hdr + phdr->p_offset,
 705                                        phdr->p_filesz);
 706                                 memset((void *)phdr->p_paddr + phdr->p_filesz,
 707                                        0, phdr->p_memsz - phdr->p_filesz);
 708                     }
 709                     phdr++;
 710                 }
 711 
 712                 for (i = 0; i < hdr->e_shnum; i++) {
 713                         /* Internal symbols and strings. */
 714                         if (sechdrs[i].sh_type == SHT_SYMTAB) {
 715                                 symindex = i;
 716                                 strindex = sechdrs[i].sh_link;
 717                                 strtab = (char *)hdr +
 718                                         sechdrs[strindex].sh_offset;
 719 
 720                                 /*
 721                                  * mark symtab's address for when we try
 722                                  * to find the magic symbols
 723                                  */
 724                                 sechdrs[i].sh_addr = (size_t) hdr +
 725                                         sechdrs[i].sh_offset;
 726                         }
 727                 }
 728         }
 729 
 730         /* make sure it's physically written out */
 731         flush_icache_range((unsigned long)v->load_addr,
 732                            (unsigned long)v->load_addr + v->len);
 733 
 734         if ((find_vpe_symbols(v, sechdrs, symindex, strtab, &mod)) < 0) {
 735                 if (v->__start == 0) {
 736                         pr_warn("VPE loader: program does not contain a __start symbol\n");
 737                         return -ENOEXEC;
 738                 }
 739 
 740                 if (v->shared_ptr == NULL)
 741                         pr_warn("VPE loader: program does not contain vpe_shared symbol.\n"
 742                                 " Unable to use AMVP (AP/SP) facilities.\n");
 743         }
 744 
 745         pr_info(" elf loaded\n");
 746         return 0;
 747 }
 748 
 749 static int getcwd(char *buff, int size)
 750 {
 751         mm_segment_t old_fs;
 752         int ret;
 753 
 754         old_fs = get_fs();
 755         set_fs(KERNEL_DS);
 756 
 757         ret = sys_getcwd(buff, size);
 758 
 759         set_fs(old_fs);
 760 
 761         return ret;
 762 }
 763 
 764 /* checks VPE is unused and gets ready to load program  */
 765 static int vpe_open(struct inode *inode, struct file *filp)
 766 {
 767         enum vpe_state state;
 768         struct vpe_notifications *notifier;
 769         struct vpe *v;
 770         int ret;
 771 
 772         if (VPE_MODULE_MINOR != iminor(inode)) {
 773                 /* assume only 1 device at the moment. */
 774                 pr_warn("VPE loader: only vpe1 is supported\n");
 775 
 776                 return -ENODEV;
 777         }
 778 
 779         v = get_vpe(aprp_cpu_index());
 780         if (v == NULL) {
 781                 pr_warn("VPE loader: unable to get vpe\n");
 782 
 783                 return -ENODEV;
 784         }
 785 
 786         state = xchg(&v->state, VPE_STATE_INUSE);
 787         if (state != VPE_STATE_UNUSED) {
 788                 pr_debug("VPE loader: tc in use dumping regs\n");
 789 
 790                 list_for_each_entry(notifier, &v->notify, list)
 791                         notifier->stop(aprp_cpu_index());
 792 
 793                 release_progmem(v->load_addr);
 794                 cleanup_tc(get_tc(aprp_cpu_index()));
 795         }
 796 
 797         /* this of-course trashes what was there before... */
 798         v->pbuffer = vmalloc(P_SIZE);
 799         if (!v->pbuffer) {
 800                 pr_warn("VPE loader: unable to allocate memory\n");
 801                 return -ENOMEM;
 802         }
 803         v->plen = P_SIZE;
 804         v->load_addr = NULL;
 805         v->len = 0;
 806 
 807         v->cwd[0] = 0;
 808         ret = getcwd(v->cwd, VPE_PATH_MAX);
 809         if (ret < 0)
 810                 pr_warn("VPE loader: open, getcwd returned %d\n", ret);
 811 
 812         v->shared_ptr = NULL;
 813         v->__start = 0;
 814 
 815         return 0;
 816 }
 817 
 818 static int vpe_release(struct inode *inode, struct file *filp)
 819 {
 820 #if defined(CONFIG_MIPS_VPE_LOADER_MT) || defined(CONFIG_MIPS_VPE_LOADER_CMP)
 821         struct vpe *v;
 822         Elf_Ehdr *hdr;
 823         int ret = 0;
 824 
 825         v = get_vpe(aprp_cpu_index());
 826         if (v == NULL)
 827                 return -ENODEV;
 828 
 829         hdr = (Elf_Ehdr *) v->pbuffer;
 830         if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) == 0) {
 831                 if (vpe_elfload(v) >= 0) {
 832                         vpe_run(v);
 833                 } else {
 834                         pr_warn("VPE loader: ELF load failed.\n");
 835                         ret = -ENOEXEC;
 836                 }
 837         } else {
 838                 pr_warn("VPE loader: only elf files are supported\n");
 839                 ret = -ENOEXEC;
 840         }
 841 
 842         /* It's good to be able to run the SP and if it chokes have a look at
 843            the /dev/rt?. But if we reset the pointer to the shared struct we
 844            lose what has happened. So perhaps if garbage is sent to the vpe
 845            device, use it as a trigger for the reset. Hopefully a nice
 846            executable will be along shortly. */
 847         if (ret < 0)
 848                 v->shared_ptr = NULL;
 849 
 850         vfree(v->pbuffer);
 851         v->plen = 0;
 852 
 853         return ret;
 854 #else
 855         pr_warn("VPE loader: ELF load failed.\n");
 856         return -ENOEXEC;
 857 #endif
 858 }
 859 
 860 static ssize_t vpe_write(struct file *file, const char __user *buffer,
 861                          size_t count, loff_t *ppos)
 862 {
 863         size_t ret = count;
 864         struct vpe *v;
 865 
 866         if (iminor(file_inode(file)) != VPE_MODULE_MINOR)
 867                 return -ENODEV;
 868 
 869         v = get_vpe(aprp_cpu_index());
 870 
 871         if (v == NULL)
 872                 return -ENODEV;
 873 
 874         if ((count + v->len) > v->plen) {
 875                 pr_warn("VPE loader: elf size too big. Perhaps strip unneeded symbols\n");
 876                 return -ENOMEM;
 877         }
 878 
 879         count -= copy_from_user(v->pbuffer + v->len, buffer, count);
 880         if (!count)
 881                 return -EFAULT;
 882 
 883         v->len += count;
 884         return ret;
 885 }
 886 
 887 const struct file_operations vpe_fops = {
 888         .owner = THIS_MODULE,
 889         .open = vpe_open,
 890         .release = vpe_release,
 891         .write = vpe_write,
 892         .llseek = noop_llseek,
 893 };
 894 
 895 void *vpe_get_shared(int index)
 896 {
 897         struct vpe *v = get_vpe(index);
 898 
 899         if (v == NULL)
 900                 return NULL;
 901 
 902         return v->shared_ptr;
 903 }
 904 EXPORT_SYMBOL(vpe_get_shared);
 905 
 906 int vpe_notify(int index, struct vpe_notifications *notify)
 907 {
 908         struct vpe *v = get_vpe(index);
 909 
 910         if (v == NULL)
 911                 return -1;
 912 
 913         list_add(&notify->list, &v->notify);
 914         return 0;
 915 }
 916 EXPORT_SYMBOL(vpe_notify);
 917 
 918 char *vpe_getcwd(int index)
 919 {
 920         struct vpe *v = get_vpe(index);
 921 
 922         if (v == NULL)
 923                 return NULL;
 924 
 925         return v->cwd;
 926 }
 927 EXPORT_SYMBOL(vpe_getcwd);
 928 
 929 module_init(vpe_module_init);
 930 module_exit(vpe_module_exit);
 931 MODULE_DESCRIPTION("MIPS VPE Loader");
 932 MODULE_AUTHOR("Elizabeth Oldham, MIPS Technologies, Inc.");
 933 MODULE_LICENSE("GPL");
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root/arch/mips/kernel/vpe.c

DEFINITIONS
