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


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]

FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_ctf.c

Version: -  FREEBSD  -  FREEBSD-13-STABLE  -  FREEBSD-13-0  -  FREEBSD-12-STABLE  -  FREEBSD-12-0  -  FREEBSD-11-STABLE  -  FREEBSD-11-0  -  FREEBSD-10-STABLE  -  FREEBSD-10-0  -  FREEBSD-9-STABLE  -  FREEBSD-9-0  -  FREEBSD-8-STABLE  -  FREEBSD-8-0  -  FREEBSD-7-STABLE  -  FREEBSD-7-0  -  FREEBSD-6-STABLE  -  FREEBSD-6-0  -  FREEBSD-5-STABLE  -  FREEBSD-5-0  -  FREEBSD-4-STABLE  -  FREEBSD-3-STABLE  -  FREEBSD22  -  l41  -  OPENBSD  -  linux-2.6  -  MK84  -  PLAN9  -  xnu-8792 
SearchContext: -  none  -  3  -  10 

    1 /*-
    2  * Copyright (c) 2008 John Birrell <jb@freebsd.org>
    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  * 1. Redistributions of source code must retain the above copyright
    9  *    notice, this list of conditions and the following disclaimer.
   10  * 2. Redistributions in binary form must reproduce the above copyright
   11  *    notice, this list of conditions and the following disclaimer in the
   12  *    documentation and/or other materials provided with the distribution.
   13  *
   14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
   15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
   18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   24  * SUCH DAMAGE.
   25  *
   26  * $FreeBSD: releng/10.0/sys/kern/kern_ctf.c 241896 2012-10-22 17:50:54Z kib $
   27  */
   28 
   29 /*
   30  * Note this file is included by both link_elf.c and link_elf_obj.c.
   31  *
   32  * The CTF header structure definition can't be used here because it's
   33  * (annoyingly) covered by the CDDL. We will just use a few bytes from
   34  * it as an integer array where we 'know' what they mean.
   35  */
   36 #define CTF_HDR_SIZE            36
   37 #define CTF_HDR_STRTAB_U32      7
   38 #define CTF_HDR_STRLEN_U32      8
   39 
   40 #ifdef DDB_CTF
   41 static void *
   42 z_alloc(void *nil, u_int items, u_int size)
   43 {
   44         void *ptr;
   45 
   46         ptr = malloc(items * size, M_TEMP, M_NOWAIT);
   47         return ptr;
   48 }
   49 
   50 static void
   51 z_free(void *nil, void *ptr)
   52 {
   53         free(ptr, M_TEMP);
   54 }
   55 
   56 #endif
   57 
   58 static int
   59 link_elf_ctf_get(linker_file_t lf, linker_ctf_t *lc)
   60 {
   61 #ifdef DDB_CTF
   62         Elf_Ehdr *hdr = NULL;
   63         Elf_Shdr *shdr = NULL;
   64         caddr_t ctftab = NULL;
   65         caddr_t raw = NULL;
   66         caddr_t shstrtab = NULL;
   67         elf_file_t ef = (elf_file_t) lf;
   68         int flags;
   69         int i;
   70         int nbytes;
   71         ssize_t resid;
   72         size_t sz;
   73         struct nameidata nd;
   74         struct thread *td = curthread;
   75         uint8_t ctf_hdr[CTF_HDR_SIZE];
   76 #endif
   77         int error = 0;
   78 
   79         if (lf == NULL || lc == NULL)
   80                 return (EINVAL);
   81 
   82         /* Set the defaults for no CTF present. That's not a crime! */
   83         bzero(lc, sizeof(*lc));
   84 
   85 #ifdef DDB_CTF
   86         /*
   87          * First check if we've tried to load CTF data previously and the
   88          * CTF ELF section wasn't found. We flag that condition by setting
   89          * ctfcnt to -1. See below.
   90          */
   91         if (ef->ctfcnt < 0)
   92                 return (EFTYPE);
   93 
   94         /* Now check if we've already loaded the CTF data.. */
   95         if (ef->ctfcnt > 0) {
   96                 /* We only need to load once. */
   97                 lc->ctftab = ef->ctftab;
   98                 lc->ctfcnt = ef->ctfcnt;
   99                 lc->symtab = ef->ddbsymtab;
  100                 lc->strtab = ef->ddbstrtab;
  101                 lc->strcnt = ef->ddbstrcnt;
  102                 lc->nsym   = ef->ddbsymcnt;
  103                 lc->ctfoffp = (uint32_t **) &ef->ctfoff;
  104                 lc->typoffp = (uint32_t **) &ef->typoff;
  105                 lc->typlenp = &ef->typlen;
  106                 return (0);
  107         }
  108 
  109         /*
  110          * We need to try reading the CTF data. Flag no CTF data present
  111          * by default and if we actually succeed in reading it, we'll
  112          * update ctfcnt to the number of bytes read.
  113          */
  114         ef->ctfcnt = -1;
  115 
  116         NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, lf->pathname, td);
  117         flags = FREAD;
  118         error = vn_open(&nd, &flags, 0, NULL);
  119         if (error)
  120                 return (error);
  121         NDFREE(&nd, NDF_ONLY_PNBUF);
  122 
  123         /* Allocate memory for the FLF header. */
  124         if ((hdr = malloc(sizeof(*hdr), M_LINKER, M_WAITOK)) == NULL) {
  125                 error = ENOMEM;
  126                 goto out;
  127         }
  128 
  129         /* Read the ELF header. */
  130         if ((error = vn_rdwr(UIO_READ, nd.ni_vp, hdr, sizeof(*hdr),
  131             0, UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, &resid,
  132             td)) != 0)
  133                 goto out;
  134 
  135         /* Sanity check. */
  136         if (!IS_ELF(*hdr)) {
  137                 error = ENOEXEC;
  138                 goto out;
  139         }
  140 
  141         nbytes = hdr->e_shnum * hdr->e_shentsize;
  142         if (nbytes == 0 || hdr->e_shoff == 0 ||
  143             hdr->e_shentsize != sizeof(Elf_Shdr)) {
  144                 error = ENOEXEC;
  145                 goto out;
  146         }
  147 
  148         /* Allocate memory for all the section headers */
  149         if ((shdr = malloc(nbytes, M_LINKER, M_WAITOK)) == NULL) {
  150                 error = ENOMEM;
  151                 goto out;
  152         }
  153 
  154         /* Read all the section headers */
  155         if ((error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)shdr, nbytes,
  156             hdr->e_shoff, UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
  157             &resid, td)) != 0)
  158                 goto out;
  159 
  160         /*
  161          * We need to search for the CTF section by name, so if the
  162          * section names aren't present, then we can't locate the
  163          * .SUNW_ctf section containing the CTF data.
  164          */
  165         if (hdr->e_shstrndx == 0 || shdr[hdr->e_shstrndx].sh_type != SHT_STRTAB) {
  166                 printf("%s(%d): module %s e_shstrndx is %d, sh_type is %d\n",
  167                     __func__, __LINE__, lf->pathname, hdr->e_shstrndx,
  168                     shdr[hdr->e_shstrndx].sh_type);
  169                 error = EFTYPE;
  170                 goto out;
  171         }
  172 
  173         /* Allocate memory to buffer the section header strings. */
  174         if ((shstrtab = malloc(shdr[hdr->e_shstrndx].sh_size, M_LINKER,
  175             M_WAITOK)) == NULL) {
  176                 error = ENOMEM;
  177                 goto out;
  178         }
  179 
  180         /* Read the section header strings. */
  181         if ((error = vn_rdwr(UIO_READ, nd.ni_vp, shstrtab,
  182             shdr[hdr->e_shstrndx].sh_size, shdr[hdr->e_shstrndx].sh_offset,
  183             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, &resid,
  184             td)) != 0)
  185                 goto out;
  186 
  187         /* Search for the section containing the CTF data. */
  188         for (i = 0; i < hdr->e_shnum; i++)
  189                 if (strcmp(".SUNW_ctf", shstrtab + shdr[i].sh_name) == 0)
  190                         break;
  191 
  192         /* Check if the CTF section wasn't found. */
  193         if (i >= hdr->e_shnum) {
  194                 printf("%s(%d): module %s has no .SUNW_ctf section\n",
  195                     __func__, __LINE__, lf->pathname);
  196                 error = EFTYPE;
  197                 goto out;
  198         }
  199 
  200         /* Read the CTF header. */
  201         if ((error = vn_rdwr(UIO_READ, nd.ni_vp, ctf_hdr, sizeof(ctf_hdr),
  202             shdr[i].sh_offset, UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred,
  203             NOCRED, &resid, td)) != 0)
  204                 goto out;
  205 
  206         /* Check the CTF magic number. (XXX check for big endian!) */
  207         if (ctf_hdr[0] != 0xf1 || ctf_hdr[1] != 0xcf) {
  208                 printf("%s(%d): module %s has invalid format\n",
  209                     __func__, __LINE__, lf->pathname);
  210                 error = EFTYPE;
  211                 goto out;
  212         }
  213 
  214         /* Check if version 2. */
  215         if (ctf_hdr[2] != 2) {
  216                 printf("%s(%d): module %s CTF format version is %d "
  217                     "(2 expected)\n",
  218                     __func__, __LINE__, lf->pathname, ctf_hdr[2]);
  219                 error = EFTYPE;
  220                 goto out;
  221         }
  222 
  223         /* Check if the data is compressed. */
  224         if ((ctf_hdr[3] & 0x1) != 0) {
  225                 uint32_t *u32 = (uint32_t *) ctf_hdr;
  226 
  227                 /*
  228                  * The last two fields in the CTF header are the offset
  229                  * from the end of the header to the start of the string
  230                  * data and the length of that string data. se this
  231                  * information to determine the decompressed CTF data
  232                  * buffer required.
  233                  */
  234                 sz = u32[CTF_HDR_STRTAB_U32] + u32[CTF_HDR_STRLEN_U32] +
  235                     sizeof(ctf_hdr);
  236 
  237                 /*
  238                  * Allocate memory for the compressed CTF data, including
  239                  * the header (which isn't compressed).
  240                  */
  241                 if ((raw = malloc(shdr[i].sh_size, M_LINKER, M_WAITOK)) == NULL) {
  242                         error = ENOMEM;
  243                         goto out;
  244                 }
  245         } else {
  246                 /*
  247                  * The CTF data is not compressed, so the ELF section
  248                  * size is the same as the buffer size required.
  249                  */
  250                 sz = shdr[i].sh_size;
  251         }
  252 
  253         /*
  254          * Allocate memory to buffer the CTF data in it's decompressed
  255          * form.
  256          */
  257         if ((ctftab = malloc(sz, M_LINKER, M_WAITOK)) == NULL) {
  258                 error = ENOMEM;
  259                 goto out;
  260         }
  261 
  262         /*
  263          * Read the CTF data into the raw buffer if compressed, or
  264          * directly into the CTF buffer otherwise.
  265          */
  266         if ((error = vn_rdwr(UIO_READ, nd.ni_vp, raw == NULL ? ctftab : raw,
  267             shdr[i].sh_size, shdr[i].sh_offset, UIO_SYSSPACE, IO_NODELOCKED,
  268             td->td_ucred, NOCRED, &resid, td)) != 0)
  269                 goto out;
  270 
  271         /* Check if decompression is required. */
  272         if (raw != NULL) {
  273                 z_stream zs;
  274                 int ret;
  275 
  276                 /*
  277                  * The header isn't compressed, so copy that into the
  278                  * CTF buffer first.
  279                  */
  280                 bcopy(ctf_hdr, ctftab, sizeof(ctf_hdr));
  281 
  282                 /* Initialise the zlib structure. */
  283                 bzero(&zs, sizeof(zs));
  284                 zs.zalloc = z_alloc;
  285                 zs.zfree = z_free;
  286 
  287                 if (inflateInit(&zs) != Z_OK) {
  288                         error = EIO;
  289                         goto out;
  290                 }
  291 
  292                 zs.avail_in = shdr[i].sh_size - sizeof(ctf_hdr);
  293                 zs.next_in = ((uint8_t *) raw) + sizeof(ctf_hdr);
  294                 zs.avail_out = sz - sizeof(ctf_hdr);
  295                 zs.next_out = ((uint8_t *) ctftab) + sizeof(ctf_hdr);
  296                 if ((ret = inflate(&zs, Z_FINISH)) != Z_STREAM_END) {
  297                         printf("%s(%d): zlib inflate returned %d\n", __func__, __LINE__, ret);
  298                         error = EIO;
  299                         goto out;
  300                 }
  301         }
  302 
  303         /* Got the CTF data! */
  304         ef->ctftab = ctftab;
  305         ef->ctfcnt = shdr[i].sh_size;
  306 
  307         /* We'll retain the memory allocated for the CTF data. */
  308         ctftab = NULL;
  309 
  310         /* Let the caller use the CTF data read. */
  311         lc->ctftab = ef->ctftab;
  312         lc->ctfcnt = ef->ctfcnt;
  313         lc->symtab = ef->ddbsymtab;
  314         lc->strtab = ef->ddbstrtab;
  315         lc->strcnt = ef->ddbstrcnt;
  316         lc->nsym   = ef->ddbsymcnt;
  317         lc->ctfoffp = (uint32_t **) &ef->ctfoff;
  318         lc->typoffp = (uint32_t **) &ef->typoff;
  319         lc->typlenp = &ef->typlen;
  320 
  321 out:
  322         VOP_UNLOCK(nd.ni_vp, 0);
  323         vn_close(nd.ni_vp, FREAD, td->td_ucred, td);
  324 
  325         if (hdr != NULL)
  326                 free(hdr, M_LINKER);
  327         if (shdr != NULL)
  328                 free(shdr, M_LINKER);
  329         if (shstrtab != NULL)
  330                 free(shstrtab, M_LINKER);
  331         if (ctftab != NULL)
  332                 free(ctftab, M_LINKER);
  333         if (raw != NULL)
  334                 free(raw, M_LINKER);
  335 #else
  336         error = EOPNOTSUPP;
  337 #endif
  338 
  339         return (error);
  340 }

Cache object: bfcc0e0aa029601dc7639669ac27072c


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]


This page is part of the FreeBSD/Linux Linux Kernel Cross-Reference, and was automatically generated using a modified version of the LXR engine.