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  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
    3  *
    4  * Copyright (c) 2008 John Birrell <jb@freebsd.org>
    5  * All rights reserved.
    6  *
    7  * Redistribution and use in source and binary forms, with or without
    8  * modification, are permitted provided that the following conditions
    9  * are met:
   10  * 1. Redistributions of source code must retain the above copyright
   11  *    notice, this list of conditions and the following disclaimer.
   12  * 2. Redistributions in binary form must reproduce the above copyright
   13  *    notice, this list of conditions and the following disclaimer in the
   14  *    documentation and/or other materials provided with the distribution.
   15  *
   16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
   17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
   20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   26  * SUCH DAMAGE.
   27  *
   28  * $FreeBSD: releng/12.0/sys/kern/kern_ctf.c 328218 2018-01-21 15:42:36Z pfg $
   29  */
   30 
   31 /*
   32  * Note this file is included by both link_elf.c and link_elf_obj.c.
   33  *
   34  * The CTF header structure definition can't be used here because it's
   35  * (annoyingly) covered by the CDDL. We will just use a few bytes from
   36  * it as an integer array where we 'know' what they mean.
   37  */
   38 #define CTF_HDR_SIZE            36
   39 #define CTF_HDR_STRTAB_U32      7
   40 #define CTF_HDR_STRLEN_U32      8
   41 
   42 #ifdef DDB_CTF
   43 static void *
   44 z_alloc(void *nil, u_int items, u_int size)
   45 {
   46         void *ptr;
   47 
   48         ptr = malloc(items * size, M_TEMP, M_NOWAIT);
   49         return ptr;
   50 }
   51 
   52 static void
   53 z_free(void *nil, void *ptr)
   54 {
   55         free(ptr, M_TEMP);
   56 }
   57 
   58 #endif
   59 
   60 static int
   61 link_elf_ctf_get(linker_file_t lf, linker_ctf_t *lc)
   62 {
   63 #ifdef DDB_CTF
   64         Elf_Ehdr *hdr = NULL;
   65         Elf_Shdr *shdr = NULL;
   66         caddr_t ctftab = NULL;
   67         caddr_t raw = NULL;
   68         caddr_t shstrtab = NULL;
   69         elf_file_t ef = (elf_file_t) lf;
   70         int flags;
   71         int i;
   72         int nbytes;
   73         size_t sz;
   74         struct nameidata nd;
   75         struct thread *td = curthread;
   76         uint8_t ctf_hdr[CTF_HDR_SIZE];
   77 #endif
   78         int error = 0;
   79 
   80         if (lf == NULL || lc == NULL)
   81                 return (EINVAL);
   82 
   83         /* Set the defaults for no CTF present. That's not a crime! */
   84         bzero(lc, sizeof(*lc));
   85 
   86 #ifdef DDB_CTF
   87         /*
   88          * First check if we've tried to load CTF data previously and the
   89          * CTF ELF section wasn't found. We flag that condition by setting
   90          * ctfcnt to -1. See below.
   91          */
   92         if (ef->ctfcnt < 0)
   93                 return (EFTYPE);
   94 
   95         /* Now check if we've already loaded the CTF data.. */
   96         if (ef->ctfcnt > 0) {
   97                 /* We only need to load once. */
   98                 lc->ctftab = ef->ctftab;
   99                 lc->ctfcnt = ef->ctfcnt;
  100                 lc->symtab = ef->ddbsymtab;
  101                 lc->strtab = ef->ddbstrtab;
  102                 lc->strcnt = ef->ddbstrcnt;
  103                 lc->nsym   = ef->ddbsymcnt;
  104                 lc->ctfoffp = (uint32_t **) &ef->ctfoff;
  105                 lc->typoffp = (uint32_t **) &ef->typoff;
  106                 lc->typlenp = &ef->typlen;
  107                 return (0);
  108         }
  109 
  110         /*
  111          * We need to try reading the CTF data. Flag no CTF data present
  112          * by default and if we actually succeed in reading it, we'll
  113          * update ctfcnt to the number of bytes read.
  114          */
  115         ef->ctfcnt = -1;
  116 
  117         NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, lf->pathname, td);
  118         flags = FREAD;
  119         error = vn_open(&nd, &flags, 0, NULL);
  120         if (error)
  121                 return (error);
  122         NDFREE(&nd, NDF_ONLY_PNBUF);
  123 
  124         /* Allocate memory for the FLF header. */
  125         hdr = malloc(sizeof(*hdr), M_LINKER, M_WAITOK);
  126 
  127         /* Read the ELF header. */
  128         if ((error = vn_rdwr(UIO_READ, nd.ni_vp, hdr, sizeof(*hdr),
  129             0, UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, NULL,
  130             td)) != 0)
  131                 goto out;
  132 
  133         /* Sanity check. */
  134         if (!IS_ELF(*hdr)) {
  135                 error = ENOEXEC;
  136                 goto out;
  137         }
  138 
  139         nbytes = hdr->e_shnum * hdr->e_shentsize;
  140         if (nbytes == 0 || hdr->e_shoff == 0 ||
  141             hdr->e_shentsize != sizeof(Elf_Shdr)) {
  142                 error = ENOEXEC;
  143                 goto out;
  144         }
  145 
  146         /* Allocate memory for all the section headers */
  147         shdr = malloc(nbytes, M_LINKER, M_WAITOK);
  148 
  149         /* Read all the section headers */
  150         if ((error = vn_rdwr(UIO_READ, nd.ni_vp, (caddr_t)shdr, nbytes,
  151             hdr->e_shoff, UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED,
  152             NULL, td)) != 0)
  153                 goto out;
  154 
  155         /*
  156          * We need to search for the CTF section by name, so if the
  157          * section names aren't present, then we can't locate the
  158          * .SUNW_ctf section containing the CTF data.
  159          */
  160         if (hdr->e_shstrndx == 0 || shdr[hdr->e_shstrndx].sh_type != SHT_STRTAB) {
  161                 printf("%s(%d): module %s e_shstrndx is %d, sh_type is %d\n",
  162                     __func__, __LINE__, lf->pathname, hdr->e_shstrndx,
  163                     shdr[hdr->e_shstrndx].sh_type);
  164                 error = EFTYPE;
  165                 goto out;
  166         }
  167 
  168         /* Allocate memory to buffer the section header strings. */
  169         shstrtab = malloc(shdr[hdr->e_shstrndx].sh_size, M_LINKER, M_WAITOK);
  170 
  171         /* Read the section header strings. */
  172         if ((error = vn_rdwr(UIO_READ, nd.ni_vp, shstrtab,
  173             shdr[hdr->e_shstrndx].sh_size, shdr[hdr->e_shstrndx].sh_offset,
  174             UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred, NOCRED, NULL, td)) != 0)
  175                 goto out;
  176 
  177         /* Search for the section containing the CTF data. */
  178         for (i = 0; i < hdr->e_shnum; i++)
  179                 if (strcmp(".SUNW_ctf", shstrtab + shdr[i].sh_name) == 0)
  180                         break;
  181 
  182         /* Check if the CTF section wasn't found. */
  183         if (i >= hdr->e_shnum) {
  184                 printf("%s(%d): module %s has no .SUNW_ctf section\n",
  185                     __func__, __LINE__, lf->pathname);
  186                 error = EFTYPE;
  187                 goto out;
  188         }
  189 
  190         /* Read the CTF header. */
  191         if ((error = vn_rdwr(UIO_READ, nd.ni_vp, ctf_hdr, sizeof(ctf_hdr),
  192             shdr[i].sh_offset, UIO_SYSSPACE, IO_NODELOCKED, td->td_ucred,
  193             NOCRED, NULL, td)) != 0)
  194                 goto out;
  195 
  196         /* Check the CTF magic number. (XXX check for big endian!) */
  197         if (ctf_hdr[0] != 0xf1 || ctf_hdr[1] != 0xcf) {
  198                 printf("%s(%d): module %s has invalid format\n",
  199                     __func__, __LINE__, lf->pathname);
  200                 error = EFTYPE;
  201                 goto out;
  202         }
  203 
  204         /* Check if version 2. */
  205         if (ctf_hdr[2] != 2) {
  206                 printf("%s(%d): module %s CTF format version is %d "
  207                     "(2 expected)\n",
  208                     __func__, __LINE__, lf->pathname, ctf_hdr[2]);
  209                 error = EFTYPE;
  210                 goto out;
  211         }
  212 
  213         /* Check if the data is compressed. */
  214         if ((ctf_hdr[3] & 0x1) != 0) {
  215                 uint32_t *u32 = (uint32_t *) ctf_hdr;
  216 
  217                 /*
  218                  * The last two fields in the CTF header are the offset
  219                  * from the end of the header to the start of the string
  220                  * data and the length of that string data. se this
  221                  * information to determine the decompressed CTF data
  222                  * buffer required.
  223                  */
  224                 sz = u32[CTF_HDR_STRTAB_U32] + u32[CTF_HDR_STRLEN_U32] +
  225                     sizeof(ctf_hdr);
  226 
  227                 /*
  228                  * Allocate memory for the compressed CTF data, including
  229                  * the header (which isn't compressed).
  230                  */
  231                 raw = malloc(shdr[i].sh_size, M_LINKER, M_WAITOK);
  232         } else {
  233                 /*
  234                  * The CTF data is not compressed, so the ELF section
  235                  * size is the same as the buffer size required.
  236                  */
  237                 sz = shdr[i].sh_size;
  238         }
  239 
  240         /*
  241          * Allocate memory to buffer the CTF data in its decompressed
  242          * form.
  243          */
  244         ctftab = malloc(sz, M_LINKER, M_WAITOK);
  245 
  246         /*
  247          * Read the CTF data into the raw buffer if compressed, or
  248          * directly into the CTF buffer otherwise.
  249          */
  250         if ((error = vn_rdwr(UIO_READ, nd.ni_vp, raw == NULL ? ctftab : raw,
  251             shdr[i].sh_size, shdr[i].sh_offset, UIO_SYSSPACE, IO_NODELOCKED,
  252             td->td_ucred, NOCRED, NULL, td)) != 0)
  253                 goto out;
  254 
  255         /* Check if decompression is required. */
  256         if (raw != NULL) {
  257                 z_stream zs;
  258                 int ret;
  259 
  260                 /*
  261                  * The header isn't compressed, so copy that into the
  262                  * CTF buffer first.
  263                  */
  264                 bcopy(ctf_hdr, ctftab, sizeof(ctf_hdr));
  265 
  266                 /* Initialise the zlib structure. */
  267                 bzero(&zs, sizeof(zs));
  268                 zs.zalloc = z_alloc;
  269                 zs.zfree = z_free;
  270 
  271                 if (inflateInit(&zs) != Z_OK) {
  272                         error = EIO;
  273                         goto out;
  274                 }
  275 
  276                 zs.avail_in = shdr[i].sh_size - sizeof(ctf_hdr);
  277                 zs.next_in = ((uint8_t *) raw) + sizeof(ctf_hdr);
  278                 zs.avail_out = sz - sizeof(ctf_hdr);
  279                 zs.next_out = ((uint8_t *) ctftab) + sizeof(ctf_hdr);
  280                 ret = inflate(&zs, Z_FINISH);
  281                 inflateEnd(&zs);
  282                 if (ret != Z_STREAM_END) {
  283                         printf("%s(%d): zlib inflate returned %d\n", __func__, __LINE__, ret);
  284                         error = EIO;
  285                         goto out;
  286                 }
  287         }
  288 
  289         /* Got the CTF data! */
  290         ef->ctftab = ctftab;
  291         ef->ctfcnt = shdr[i].sh_size;
  292 
  293         /* We'll retain the memory allocated for the CTF data. */
  294         ctftab = NULL;
  295 
  296         /* Let the caller use the CTF data read. */
  297         lc->ctftab = ef->ctftab;
  298         lc->ctfcnt = ef->ctfcnt;
  299         lc->symtab = ef->ddbsymtab;
  300         lc->strtab = ef->ddbstrtab;
  301         lc->strcnt = ef->ddbstrcnt;
  302         lc->nsym   = ef->ddbsymcnt;
  303         lc->ctfoffp = (uint32_t **) &ef->ctfoff;
  304         lc->typoffp = (uint32_t **) &ef->typoff;
  305         lc->typlenp = &ef->typlen;
  306 
  307 out:
  308         VOP_UNLOCK(nd.ni_vp, 0);
  309         vn_close(nd.ni_vp, FREAD, td->td_ucred, td);
  310 
  311         if (hdr != NULL)
  312                 free(hdr, M_LINKER);
  313         if (shdr != NULL)
  314                 free(shdr, M_LINKER);
  315         if (shstrtab != NULL)
  316                 free(shstrtab, M_LINKER);
  317         if (ctftab != NULL)
  318                 free(ctftab, M_LINKER);
  319         if (raw != NULL)
  320                 free(raw, M_LINKER);
  321 #else
  322         error = EOPNOTSUPP;
  323 #endif
  324 
  325         return (error);
  326 }
Cache object: 3e50e1a36c42176e1b8fe5a061cefd08
[ 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.
FreeBSD/Linux Kernel Cross Reference sys/kern/kern_ctf.c

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