sys/platform/pc64/x86_64/dump_machdep.c

   1 /*-
   2  * Copyright (c) 2002 Marcel Moolenaar
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  *
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  *
  15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  25  *
  26  * $FreeBSD: src/sys/amd64/amd64/dump_machdep.c,v 1.18 2009/05/29 21:27:12 jamie Exp $
  27  */
  28
  29 #include <sys/param.h>
  30 #include <sys/systm.h>
  31 #include <sys/conf.h>
  32 #include <sys/cons.h>
  33 #include <sys/sysctl.h>
  34 #include <sys/device.h>
  35 #include <sys/kernel.h>
  36 #include <sys/kerneldump.h>
  37 #include <vm/vm.h>
  38 #include <vm/pmap.h>
  39 #include <machine/elf.h>
  40 #include <machine/md_var.h>
  41 #include <machine/thread.h>
  42 #include <sys/thread2.h>
  43
  44 CTASSERT(sizeof(struct kerneldumpheader) == 512);
  45
  46 int do_minidump = 1;
  47 TUNABLE_INT("debug.minidump", &do_minidump);
  48 SYSCTL_INT(_debug, OID_AUTO, minidump, CTLFLAG_RW, &do_minidump, 0,
  49     "Enable mini crash dumps");
  50
  51 /*
  52  * Don't touch the first SIZEOF_METADATA bytes on the dump device. This
  53  * is to protect us from metadata and to protect metadata from us.
  54  */
  55 #define SIZEOF_METADATA         (64*1024)
  56
  57 #define MD_ALIGN(x)     (((off_t)(x) + PAGE_MASK) & ~PAGE_MASK)
  58 #define DEV_ALIGN(x)    (((off_t)(x) + (DEV_BSIZE-1)) & ~(DEV_BSIZE-1))
  59
  60 struct md_pa {
  61         vm_paddr_t md_start;
  62         vm_paddr_t md_size;
  63 };
  64
  65 typedef int callback_t(struct md_pa *, int, void *);
  66
  67 static struct kerneldumpheader kdh;
  68 static off_t dumplo, fileofs;
  69
  70 /* Handle buffered writes. */
  71 static char buffer[DEV_BSIZE];
  72 static size_t fragsz;
  73
  74 /* 20 phys_avail entry pairs correspond to 10 md_pa's */
  75 static struct md_pa dump_map[10];
  76
  77 static void
  78 md_pa_init(void)
  79 {
  80         int n, idx;
  81
  82         bzero(dump_map, sizeof(dump_map));
  83         for (n = 0; n < sizeof(dump_map) / sizeof(dump_map[0]); n++) {
  84                 idx = n * 2;
  85                 if (dump_avail[idx] == 0 && dump_avail[idx + 1] == 0)
  86                         break;
  87                 dump_map[n].md_start = dump_avail[idx];
  88                 dump_map[n].md_size = dump_avail[idx + 1] - dump_avail[idx];
  89         }
  90 }
  91
  92 static struct md_pa *
  93 md_pa_first(void)
  94 {
  95
  96         return (&dump_map[0]);
  97 }
  98
  99 static struct md_pa *
 100 md_pa_next(struct md_pa *mdp)
 101 {
 102
 103         mdp++;
 104         if (mdp->md_size == 0)
 105                 mdp = NULL;
 106         return (mdp);
 107 }
 108
 109 static int
 110 buf_write(struct dumperinfo *di, char *ptr, size_t sz)
 111 {
 112         size_t len;
 113         int error;
 114
 115         while (sz) {
 116                 len = DEV_BSIZE - fragsz;
 117                 if (len > sz)
 118                         len = sz;
 119                 bcopy(ptr, buffer + fragsz, len);
 120                 fragsz += len;
 121                 ptr += len;
 122                 sz -= len;
 123                 if (fragsz == DEV_BSIZE) {
 124                         error = dev_ddump(di->priv, buffer, 0, dumplo,
 125                             DEV_BSIZE);
 126                         if (error)
 127                                 return error;
 128                         dumplo += DEV_BSIZE;
 129                         fragsz = 0;
 130                 }
 131         }
 132
 133         return (0);
 134 }
 135
 136 static int
 137 buf_flush(struct dumperinfo *di)
 138 {
 139         int error;
 140
 141         if (fragsz == 0)
 142                 return (0);
 143
 144         error = dev_ddump(di->priv, buffer, 0, dumplo, DEV_BSIZE);
 145         dumplo += DEV_BSIZE;
 146         fragsz = 0;
 147         return (error);
 148 }
 149
 150 #define PG2MB(pgs) ((pgs + (1 << 8) - 1) >> 8)
 151
 152 static int
 153 cb_dumpdata(struct md_pa *mdp, int seqnr, void *arg)
 154 {
 155         struct dumperinfo *di = (struct dumperinfo*)arg;
 156         vm_paddr_t a, pa;
 157         void *va;
 158         uint64_t pgs;
 159         size_t counter, sz, chunk;
 160         int i, c, error, twiddle;
 161
 162         error = 0;      /* catch case in which chunk size is 0 */
 163         counter = 0;    /* Update twiddle every 16MB */
 164         twiddle = 0;
 165         va = 0;
 166         pgs = mdp->md_size / PAGE_SIZE;
 167         pa = mdp->md_start;
 168
 169         kprintf("  chunk %d: %ldMB (%ld pages)", seqnr, PG2MB(pgs), pgs);
 170
 171         while (pgs) {
 172                 chunk = pgs;
 173                 if (chunk > MAXDUMPPGS)
 174                         chunk = MAXDUMPPGS;
 175                 sz = chunk << PAGE_SHIFT;
 176                 counter += sz;
 177                 if (counter >> 24) {
 178                         kprintf(" %ld", PG2MB(pgs));
 179                         counter &= (1<<24) - 1;
 180                 }
 181                 for (i = 0; i < chunk; i++) {
 182                         a = pa + i * PAGE_SIZE;
 183                         va = pmap_kenter_temporary(trunc_page(a), i);
 184                 }
 185                 error = dev_ddump(di->priv, va, 0, dumplo, sz);
 186                 if (error)
 187                         break;
 188                 dumplo += sz;
 189                 pgs -= chunk;
 190                 pa += sz;
 191
 192                 /* Check for user abort. */
 193                 c = cncheckc();
 194                 if (c == 0x03)
 195                         return (ECANCELED);
 196                 if (c != -1)
 197                         kprintf(" (CTRL-C to abort) ");
 198         }
 199         kprintf(" ... %s\n", (error) ? "fail" : "ok");
 200         return (error);
 201 }
 202
 203 static int
 204 cb_dumphdr(struct md_pa *mdp, int seqnr, void *arg)
 205 {
 206         struct dumperinfo *di = (struct dumperinfo*)arg;
 207         Elf_Phdr phdr;
 208         uint64_t size;
 209         int error;
 210
 211         size = mdp->md_size;
 212         bzero(&phdr, sizeof(phdr));
 213         phdr.p_type = PT_LOAD;
 214         phdr.p_flags = PF_R;                    /* XXX */
 215         phdr.p_offset = fileofs;
 216         phdr.p_vaddr = mdp->md_start;
 217         phdr.p_paddr = mdp->md_start;
 218         phdr.p_filesz = size;
 219         phdr.p_memsz = size;
 220         phdr.p_align = PAGE_SIZE;
 221
 222         error = buf_write(di, (char*)&phdr, sizeof(phdr));
 223         fileofs += phdr.p_filesz;
 224         return (error);
 225 }
 226
 227 static int
 228 cb_size(struct md_pa *mdp, int seqnr, void *arg)
 229 {
 230         uint64_t *sz = (uint64_t*)arg;
 231
 232         *sz += (uint64_t)mdp->md_size;
 233         return (0);
 234 }
 235
 236 static int
 237 foreach_chunk(callback_t cb, void *arg)
 238 {
 239         struct md_pa *mdp;
 240         int error, seqnr;
 241
 242         seqnr = 0;
 243         mdp = md_pa_first();
 244         while (mdp != NULL) {
 245                 error = (*cb)(mdp, seqnr++, arg);
 246                 if (error)
 247                         return (-error);
 248                 mdp = md_pa_next(mdp);
 249         }
 250         return (seqnr);
 251 }
 252
 253 void
 254 dumpsys(struct dumperinfo *di)
 255 {
 256         Elf_Ehdr ehdr;
 257         uint64_t dumpsize;
 258         off_t hdrgap;
 259         size_t hdrsz;
 260         int error;
 261
 262         savectx(&dumppcb);
 263         dumpthread = curthread;
 264
 265         if (do_minidump) {
 266                 minidumpsys(di);
 267                 return;
 268         }
 269         bzero(&ehdr, sizeof(ehdr));
 270         ehdr.e_ident[EI_MAG0] = ELFMAG0;
 271         ehdr.e_ident[EI_MAG1] = ELFMAG1;
 272         ehdr.e_ident[EI_MAG2] = ELFMAG2;
 273         ehdr.e_ident[EI_MAG3] = ELFMAG3;
 274         ehdr.e_ident[EI_CLASS] = ELF_CLASS;
 275 #if BYTE_ORDER == LITTLE_ENDIAN
 276         ehdr.e_ident[EI_DATA] = ELFDATA2LSB;
 277 #else
 278         ehdr.e_ident[EI_DATA] = ELFDATA2MSB;
 279 #endif
 280         ehdr.e_ident[EI_VERSION] = EV_CURRENT;
 281         ehdr.e_ident[EI_OSABI] = ELFOSABI_STANDALONE;   /* XXX big picture? */
 282         ehdr.e_type = ET_CORE;
 283         ehdr.e_machine = EM_X86_64;
 284         ehdr.e_phoff = sizeof(ehdr);
 285         ehdr.e_flags = 0;
 286         ehdr.e_ehsize = sizeof(ehdr);
 287         ehdr.e_phentsize = sizeof(Elf_Phdr);
 288         ehdr.e_shentsize = sizeof(Elf_Shdr);
 289
 290         md_pa_init();
 291
 292         /* Calculate dump size. */
 293         dumpsize = 0L;
 294         ehdr.e_phnum = foreach_chunk(cb_size, &dumpsize);
 295         hdrsz = ehdr.e_phoff + ehdr.e_phnum * ehdr.e_phentsize;
 296         fileofs = MD_ALIGN(hdrsz);
 297         dumpsize += fileofs;
 298         hdrgap = fileofs - DEV_ALIGN(hdrsz);
 299
 300         /* Determine dump offset on device. */
 301         if (di->mediasize < SIZEOF_METADATA + dumpsize + sizeof(kdh) * 2) {
 302                 error = ENOSPC;
 303                 goto fail;
 304         }
 305         dumplo = di->mediaoffset + di->mediasize - dumpsize;
 306         dumplo -= sizeof(kdh) * 2;
 307
 308         mkdumpheader(&kdh, KERNELDUMPMAGIC, KERNELDUMP_AMD64_VERSION,
 309             dumpsize, di->blocksize);
 310
 311         kprintf("Dumping %llu MB (%d chunks)\n", (long long)dumpsize >> 20,
 312             ehdr.e_phnum);
 313
 314         /* Dump leader */
 315         error = dev_ddump(di->priv, &kdh, 0, dumplo, sizeof(kdh));
 316         if (error)
 317                 goto fail;
 318         dumplo += sizeof(kdh);
 319
 320         /* Dump ELF header */
 321         error = buf_write(di, (char*)&ehdr, sizeof(ehdr));
 322         if (error)
 323                 goto fail;
 324
 325         /* Dump program headers */
 326         error = foreach_chunk(cb_dumphdr, di);
 327         if (error < 0)
 328                 goto fail;
 329         buf_flush(di);
 330
 331         /*
 332          * All headers are written using blocked I/O, so we know the
 333          * current offset is (still) block aligned. Skip the alignement
 334          * in the file to have the segment contents aligned at page
 335          * boundary. We cannot use MD_ALIGN on dumplo, because we don't
 336          * care and may very well be unaligned within the dump device.
 337          */
 338         dumplo += hdrgap;
 339
 340         /* Dump memory chunks (updates dumplo) */
 341         error = foreach_chunk(cb_dumpdata, di);
 342         if (error < 0)
 343                 goto fail;
 344
 345         /* Dump trailer */
 346         error = dev_ddump(di->priv, &kdh, 0, dumplo, sizeof(kdh));
 347         if (error)
 348                 goto fail;
 349
 350         /* Signal completion, signoff and exit stage left. */
 351         dev_ddump(di->priv, NULL, 0, 0, 0);
 352         kprintf("\nDump complete\n");
 353         return;
 354
 355  fail:
 356         if (error < 0)
 357                 error = -error;
 358
 359         if (error == ECANCELED)
 360                 kprintf("\nDump aborted\n");
 361         else if (error == ENOSPC)
 362                 kprintf("\nDump failed. Partition too small.\n");
 363         else
 364                 kprintf("\n** DUMP FAILED (ERROR %d) **\n", error);
 365 }