The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)


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FreeBSD/Linux Kernel Cross Reference
sys/amd64/amd64/minidump_machdep.c

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    1 /*-
    2  * Copyright (c) 2006 Peter Wemm
    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 
   27 #include <sys/cdefs.h>
   28 __FBSDID("$FreeBSD: releng/10.0/sys/amd64/amd64/minidump_machdep.c 257575 2013-11-03 16:03:19Z kib $");
   29 
   30 #include "opt_pmap.h"
   31 #include "opt_watchdog.h"
   32 
   33 #include <sys/param.h>
   34 #include <sys/systm.h>
   35 #include <sys/conf.h>
   36 #include <sys/cons.h>
   37 #include <sys/kernel.h>
   38 #include <sys/kerneldump.h>
   39 #include <sys/msgbuf.h>
   40 #include <sys/watchdog.h>
   41 #include <vm/vm.h>
   42 #include <vm/vm_param.h>
   43 #include <vm/vm_page.h>
   44 #include <vm/vm_phys.h>
   45 #include <vm/pmap.h>
   46 #include <machine/atomic.h>
   47 #include <machine/elf.h>
   48 #include <machine/md_var.h>
   49 #include <machine/vmparam.h>
   50 #include <machine/minidump.h>
   51 
   52 CTASSERT(sizeof(struct kerneldumpheader) == 512);
   53 
   54 /*
   55  * Don't touch the first SIZEOF_METADATA bytes on the dump device. This
   56  * is to protect us from metadata and to protect metadata from us.
   57  */
   58 #define SIZEOF_METADATA         (64*1024)
   59 
   60 #define MD_ALIGN(x)     (((off_t)(x) + PAGE_MASK) & ~PAGE_MASK)
   61 #define DEV_ALIGN(x)    (((off_t)(x) + (DEV_BSIZE-1)) & ~(DEV_BSIZE-1))
   62 
   63 uint64_t *vm_page_dump;
   64 int vm_page_dump_size;
   65 
   66 static struct kerneldumpheader kdh;
   67 static off_t dumplo;
   68 
   69 /* Handle chunked writes. */
   70 static size_t fragsz;
   71 static void *dump_va;
   72 static size_t counter, progress, dumpsize;
   73 
   74 CTASSERT(sizeof(*vm_page_dump) == 8);
   75 
   76 static int
   77 is_dumpable(vm_paddr_t pa)
   78 {
   79         vm_page_t m;
   80         int i;
   81 
   82         if ((m = vm_phys_paddr_to_vm_page(pa)) != NULL)
   83                 return ((m->flags & PG_NODUMP) == 0);
   84         for (i = 0; dump_avail[i] != 0 || dump_avail[i + 1] != 0; i += 2) {
   85                 if (pa >= dump_avail[i] && pa < dump_avail[i + 1])
   86                         return (1);
   87         }
   88         return (0);
   89 }
   90 
   91 #define PG2MB(pgs) (((pgs) + (1 << 8) - 1) >> 8)
   92 
   93 static int
   94 blk_flush(struct dumperinfo *di)
   95 {
   96         int error;
   97 
   98         if (fragsz == 0)
   99                 return (0);
  100 
  101         error = dump_write(di, dump_va, 0, dumplo, fragsz);
  102         dumplo += fragsz;
  103         fragsz = 0;
  104         return (error);
  105 }
  106 
  107 static struct {
  108         int min_per;
  109         int max_per;
  110         int visited;
  111 } progress_track[10] = {
  112         {  0,  10, 0},
  113         { 10,  20, 0},
  114         { 20,  30, 0},
  115         { 30,  40, 0},
  116         { 40,  50, 0},
  117         { 50,  60, 0},
  118         { 60,  70, 0},
  119         { 70,  80, 0},
  120         { 80,  90, 0},
  121         { 90, 100, 0}
  122 };
  123 
  124 static void
  125 report_progress(size_t progress, size_t dumpsize)
  126 {
  127         int sofar, i;
  128 
  129         sofar = 100 - ((progress * 100) / dumpsize);
  130         for (i = 0; i < nitems(progress_track); i++) {
  131                 if (sofar < progress_track[i].min_per ||
  132                     sofar > progress_track[i].max_per)
  133                         continue;
  134                 if (progress_track[i].visited)
  135                         return;
  136                 progress_track[i].visited = 1;
  137                 printf("..%d%%", sofar);
  138                 return;
  139         }
  140 }
  141 
  142 static int
  143 blk_write(struct dumperinfo *di, char *ptr, vm_paddr_t pa, size_t sz)
  144 {
  145         size_t len;
  146         int error, i, c;
  147         u_int maxdumpsz;
  148 
  149         maxdumpsz = min(di->maxiosize, MAXDUMPPGS * PAGE_SIZE);
  150         if (maxdumpsz == 0)     /* seatbelt */
  151                 maxdumpsz = PAGE_SIZE;
  152         error = 0;
  153         if ((sz % PAGE_SIZE) != 0) {
  154                 printf("size not page aligned\n");
  155                 return (EINVAL);
  156         }
  157         if (ptr != NULL && pa != 0) {
  158                 printf("cant have both va and pa!\n");
  159                 return (EINVAL);
  160         }
  161         if ((((uintptr_t)pa) % PAGE_SIZE) != 0) {
  162                 printf("address not page aligned %p\n", ptr);
  163                 return (EINVAL);
  164         }
  165         if (ptr != NULL) {
  166                 /* If we're doing a virtual dump, flush any pre-existing pa pages */
  167                 error = blk_flush(di);
  168                 if (error)
  169                         return (error);
  170         }
  171         while (sz) {
  172                 len = maxdumpsz - fragsz;
  173                 if (len > sz)
  174                         len = sz;
  175                 counter += len;
  176                 progress -= len;
  177                 if (counter >> 24) {
  178                         report_progress(progress, dumpsize);
  179                         counter &= (1<<24) - 1;
  180                 }
  181 
  182                 wdog_kern_pat(WD_LASTVAL);
  183 
  184                 if (ptr) {
  185                         error = dump_write(di, ptr, 0, dumplo, len);
  186                         if (error)
  187                                 return (error);
  188                         dumplo += len;
  189                         ptr += len;
  190                         sz -= len;
  191                 } else {
  192                         for (i = 0; i < len; i += PAGE_SIZE)
  193                                 dump_va = pmap_kenter_temporary(pa + i, (i + fragsz) >> PAGE_SHIFT);
  194                         fragsz += len;
  195                         pa += len;
  196                         sz -= len;
  197                         if (fragsz == maxdumpsz) {
  198                                 error = blk_flush(di);
  199                                 if (error)
  200                                         return (error);
  201                         }
  202                 }
  203 
  204                 /* Check for user abort. */
  205                 c = cncheckc();
  206                 if (c == 0x03)
  207                         return (ECANCELED);
  208                 if (c != -1)
  209                         printf(" (CTRL-C to abort) ");
  210         }
  211 
  212         return (0);
  213 }
  214 
  215 /* A fake page table page, to avoid having to handle both 4K and 2M pages */
  216 static pd_entry_t fakepd[NPDEPG];
  217 
  218 void
  219 minidumpsys(struct dumperinfo *di)
  220 {
  221         uint32_t pmapsize;
  222         vm_offset_t va;
  223         int error;
  224         uint64_t bits;
  225         uint64_t *pml4, *pdp, *pd, *pt, pa;
  226         int i, ii, j, k, n, bit;
  227         int retry_count;
  228         struct minidumphdr mdhdr;
  229 
  230         retry_count = 0;
  231  retry:
  232         retry_count++;
  233         counter = 0;
  234         for (i = 0; i < nitems(progress_track); i++)
  235                 progress_track[i].visited = 0;
  236         /* Walk page table pages, set bits in vm_page_dump */
  237         pmapsize = 0;
  238         for (va = VM_MIN_KERNEL_ADDRESS; va < MAX(KERNBASE + nkpt * NBPDR,
  239             kernel_vm_end); ) {
  240                 /*
  241                  * We always write a page, even if it is zero. Each
  242                  * page written corresponds to 1GB of space
  243                  */
  244                 pmapsize += PAGE_SIZE;
  245                 ii = (va >> PML4SHIFT) & ((1ul << NPML4EPGSHIFT) - 1);
  246                 pml4 = (uint64_t *)PHYS_TO_DMAP(KPML4phys) + ii;
  247                 pdp = (uint64_t *)PHYS_TO_DMAP(*pml4 & PG_FRAME);
  248                 i = (va >> PDPSHIFT) & ((1ul << NPDPEPGSHIFT) - 1);
  249                 if ((pdp[i] & PG_V) == 0) {
  250                         va += NBPDP;
  251                         continue;
  252                 }
  253 
  254                 /*
  255                  * 1GB page is represented as 512 2MB pages in a dump.
  256                  */
  257                 if ((pdp[i] & PG_PS) != 0) {
  258                         va += NBPDP;
  259                         pa = pdp[i] & PG_PS_FRAME;
  260                         for (n = 0; n < NPDEPG * NPTEPG; n++) {
  261                                 if (is_dumpable(pa))
  262                                         dump_add_page(pa);
  263                                 pa += PAGE_SIZE;
  264                         }
  265                         continue;
  266                 }
  267 
  268                 pd = (uint64_t *)PHYS_TO_DMAP(pdp[i] & PG_FRAME);
  269                 for (n = 0; n < NPDEPG; n++, va += NBPDR) {
  270                         j = (va >> PDRSHIFT) & ((1ul << NPDEPGSHIFT) - 1);
  271 
  272                         if ((pd[j] & PG_V) == 0)
  273                                 continue;
  274 
  275                         if ((pd[j] & PG_PS) != 0) {
  276                                 /* This is an entire 2M page. */
  277                                 pa = pd[j] & PG_PS_FRAME;
  278                                 for (k = 0; k < NPTEPG; k++) {
  279                                         if (is_dumpable(pa))
  280                                                 dump_add_page(pa);
  281                                         pa += PAGE_SIZE;
  282                                 }
  283                                 continue;
  284                         }
  285 
  286                         pa = pd[j] & PG_FRAME;
  287                         /* set bit for this PTE page */
  288                         if (is_dumpable(pa))
  289                                 dump_add_page(pa);
  290                         /* and for each valid page in this 2MB block */
  291                         pt = (uint64_t *)PHYS_TO_DMAP(pd[j] & PG_FRAME);
  292                         for (k = 0; k < NPTEPG; k++) {
  293                                 if ((pt[k] & PG_V) == 0)
  294                                         continue;
  295                                 pa = pt[k] & PG_FRAME;
  296                                 if (is_dumpable(pa))
  297                                         dump_add_page(pa);
  298                         }
  299                 }
  300         }
  301 
  302         /* Calculate dump size. */
  303         dumpsize = pmapsize;
  304         dumpsize += round_page(msgbufp->msg_size);
  305         dumpsize += round_page(vm_page_dump_size);
  306         for (i = 0; i < vm_page_dump_size / sizeof(*vm_page_dump); i++) {
  307                 bits = vm_page_dump[i];
  308                 while (bits) {
  309                         bit = bsfq(bits);
  310                         pa = (((uint64_t)i * sizeof(*vm_page_dump) * NBBY) + bit) * PAGE_SIZE;
  311                         /* Clear out undumpable pages now if needed */
  312                         if (is_dumpable(pa)) {
  313                                 dumpsize += PAGE_SIZE;
  314                         } else {
  315                                 dump_drop_page(pa);
  316                         }
  317                         bits &= ~(1ul << bit);
  318                 }
  319         }
  320         dumpsize += PAGE_SIZE;
  321 
  322         /* Determine dump offset on device. */
  323         if (di->mediasize < SIZEOF_METADATA + dumpsize + sizeof(kdh) * 2) {
  324                 error = E2BIG;
  325                 goto fail;
  326         }
  327         dumplo = di->mediaoffset + di->mediasize - dumpsize;
  328         dumplo -= sizeof(kdh) * 2;
  329         progress = dumpsize;
  330 
  331         /* Initialize mdhdr */
  332         bzero(&mdhdr, sizeof(mdhdr));
  333         strcpy(mdhdr.magic, MINIDUMP_MAGIC);
  334         mdhdr.version = MINIDUMP_VERSION;
  335         mdhdr.msgbufsize = msgbufp->msg_size;
  336         mdhdr.bitmapsize = vm_page_dump_size;
  337         mdhdr.pmapsize = pmapsize;
  338         mdhdr.kernbase = VM_MIN_KERNEL_ADDRESS;
  339         mdhdr.dmapbase = DMAP_MIN_ADDRESS;
  340         mdhdr.dmapend = DMAP_MAX_ADDRESS;
  341 
  342         mkdumpheader(&kdh, KERNELDUMPMAGIC, KERNELDUMP_AMD64_VERSION, dumpsize, di->blocksize);
  343 
  344         printf("Dumping %llu out of %ju MB:", (long long)dumpsize >> 20,
  345             ptoa((uintmax_t)physmem) / 1048576);
  346 
  347         /* Dump leader */
  348         error = dump_write(di, &kdh, 0, dumplo, sizeof(kdh));
  349         if (error)
  350                 goto fail;
  351         dumplo += sizeof(kdh);
  352 
  353         /* Dump my header */
  354         bzero(&fakepd, sizeof(fakepd));
  355         bcopy(&mdhdr, &fakepd, sizeof(mdhdr));
  356         error = blk_write(di, (char *)&fakepd, 0, PAGE_SIZE);
  357         if (error)
  358                 goto fail;
  359 
  360         /* Dump msgbuf up front */
  361         error = blk_write(di, (char *)msgbufp->msg_ptr, 0, round_page(msgbufp->msg_size));
  362         if (error)
  363                 goto fail;
  364 
  365         /* Dump bitmap */
  366         error = blk_write(di, (char *)vm_page_dump, 0, round_page(vm_page_dump_size));
  367         if (error)
  368                 goto fail;
  369 
  370         /* Dump kernel page directory pages */
  371         bzero(fakepd, sizeof(fakepd));
  372         for (va = VM_MIN_KERNEL_ADDRESS; va < MAX(KERNBASE + nkpt * NBPDR,
  373             kernel_vm_end); va += NBPDP) {
  374                 ii = (va >> PML4SHIFT) & ((1ul << NPML4EPGSHIFT) - 1);
  375                 pml4 = (uint64_t *)PHYS_TO_DMAP(KPML4phys) + ii;
  376                 pdp = (uint64_t *)PHYS_TO_DMAP(*pml4 & PG_FRAME);
  377                 i = (va >> PDPSHIFT) & ((1ul << NPDPEPGSHIFT) - 1);
  378 
  379                 /* We always write a page, even if it is zero */
  380                 if ((pdp[i] & PG_V) == 0) {
  381                         error = blk_write(di, (char *)&fakepd, 0, PAGE_SIZE);
  382                         if (error)
  383                                 goto fail;
  384                         /* flush, in case we reuse fakepd in the same block */
  385                         error = blk_flush(di);
  386                         if (error)
  387                                 goto fail;
  388                         continue;
  389                 }
  390 
  391                 /* 1GB page is represented as 512 2MB pages in a dump */
  392                 if ((pdp[i] & PG_PS) != 0) {
  393                         /* PDPE and PDP have identical layout in this case */
  394                         fakepd[0] = pdp[i];
  395                         for (j = 1; j < NPDEPG; j++)
  396                                 fakepd[j] = fakepd[j - 1] + NBPDR;
  397                         error = blk_write(di, (char *)&fakepd, 0, PAGE_SIZE);
  398                         if (error)
  399                                 goto fail;
  400                         /* flush, in case we reuse fakepd in the same block */
  401                         error = blk_flush(di);
  402                         if (error)
  403                                 goto fail;
  404                         bzero(fakepd, sizeof(fakepd));
  405                         continue;
  406                 }
  407 
  408                 pd = (uint64_t *)PHYS_TO_DMAP(pdp[i] & PG_FRAME);
  409                 error = blk_write(di, (char *)pd, 0, PAGE_SIZE);
  410                 if (error)
  411                         goto fail;
  412                 error = blk_flush(di);
  413                 if (error)
  414                         goto fail;
  415         }
  416 
  417         /* Dump memory chunks */
  418         /* XXX cluster it up and use blk_dump() */
  419         for (i = 0; i < vm_page_dump_size / sizeof(*vm_page_dump); i++) {
  420                 bits = vm_page_dump[i];
  421                 while (bits) {
  422                         bit = bsfq(bits);
  423                         pa = (((uint64_t)i * sizeof(*vm_page_dump) * NBBY) + bit) * PAGE_SIZE;
  424                         error = blk_write(di, 0, pa, PAGE_SIZE);
  425                         if (error)
  426                                 goto fail;
  427                         bits &= ~(1ul << bit);
  428                 }
  429         }
  430 
  431         error = blk_flush(di);
  432         if (error)
  433                 goto fail;
  434 
  435         /* Dump trailer */
  436         error = dump_write(di, &kdh, 0, dumplo, sizeof(kdh));
  437         if (error)
  438                 goto fail;
  439         dumplo += sizeof(kdh);
  440 
  441         /* Signal completion, signoff and exit stage left. */
  442         dump_write(di, NULL, 0, 0, 0);
  443         printf("\nDump complete\n");
  444         return;
  445 
  446  fail:
  447         if (error < 0)
  448                 error = -error;
  449 
  450         printf("\n");
  451         if (error == ENOSPC) {
  452                 printf("Dump map grown while dumping. ");
  453                 if (retry_count < 5) {
  454                         printf("Retrying...\n");
  455                         goto retry;
  456                 }
  457                 printf("Dump failed.\n");
  458         }
  459         else if (error == ECANCELED)
  460                 printf("Dump aborted\n");
  461         else if (error == E2BIG)
  462                 printf("Dump failed. Partition too small.\n");
  463         else
  464                 printf("** DUMP FAILED (ERROR %d) **\n", error);
  465 }
  466 
  467 void
  468 dump_add_page(vm_paddr_t pa)
  469 {
  470         int idx, bit;
  471 
  472         pa >>= PAGE_SHIFT;
  473         idx = pa >> 6;          /* 2^6 = 64 */
  474         bit = pa & 63;
  475         atomic_set_long(&vm_page_dump[idx], 1ul << bit);
  476 }
  477 
  478 void
  479 dump_drop_page(vm_paddr_t pa)
  480 {
  481         int idx, bit;
  482 
  483         pa >>= PAGE_SHIFT;
  484         idx = pa >> 6;          /* 2^6 = 64 */
  485         bit = pa & 63;
  486         atomic_clear_long(&vm_page_dump[idx], 1ul << bit);
  487 }

Cache object: 71b011fdc9017f45fd39d66b4f9cbd36


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