The Design and Implementation of the FreeBSD Operating System, Second Edition
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FreeBSD/Linux Kernel Cross Reference
sys/kern/imgact_elf.c

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    1 /*-
    2  * Copyright (c) 2000 David O'Brien
    3  * Copyright (c) 1995-1996 Søren Schmidt
    4  * Copyright (c) 1996 Peter Wemm
    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  *    in this position and unchanged.
   13  * 2. Redistributions in binary form must reproduce the above copyright
   14  *    notice, this list of conditions and the following disclaimer in the
   15  *    documentation and/or other materials provided with the distribution.
   16  * 3. The name of the author may not be used to endorse or promote products
   17  *    derived from this software without specific prior written permission
   18  *
   19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
   20  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   21  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
   22  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
   23  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
   24  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
   25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
   26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
   28  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   29  */
   30 
   31 #include <sys/cdefs.h>
   32 __FBSDID("$FreeBSD: releng/9.0/sys/kern/imgact_elf.c 223825 2011-07-06 20:06:44Z trasz $");
   33 
   34 #include "opt_capsicum.h"
   35 #include "opt_compat.h"
   36 #include "opt_core.h"
   37 
   38 #include <sys/param.h>
   39 #include <sys/capability.h>
   40 #include <sys/exec.h>
   41 #include <sys/fcntl.h>
   42 #include <sys/imgact.h>
   43 #include <sys/imgact_elf.h>
   44 #include <sys/kernel.h>
   45 #include <sys/lock.h>
   46 #include <sys/malloc.h>
   47 #include <sys/mount.h>
   48 #include <sys/mutex.h>
   49 #include <sys/mman.h>
   50 #include <sys/namei.h>
   51 #include <sys/pioctl.h>
   52 #include <sys/proc.h>
   53 #include <sys/procfs.h>
   54 #include <sys/racct.h>
   55 #include <sys/resourcevar.h>
   56 #include <sys/sf_buf.h>
   57 #include <sys/smp.h>
   58 #include <sys/systm.h>
   59 #include <sys/signalvar.h>
   60 #include <sys/stat.h>
   61 #include <sys/sx.h>
   62 #include <sys/syscall.h>
   63 #include <sys/sysctl.h>
   64 #include <sys/sysent.h>
   65 #include <sys/vnode.h>
   66 #include <sys/syslog.h>
   67 #include <sys/eventhandler.h>
   68 
   69 #include <net/zlib.h>
   70 
   71 #include <vm/vm.h>
   72 #include <vm/vm_kern.h>
   73 #include <vm/vm_param.h>
   74 #include <vm/pmap.h>
   75 #include <vm/vm_map.h>
   76 #include <vm/vm_object.h>
   77 #include <vm/vm_extern.h>
   78 
   79 #include <machine/elf.h>
   80 #include <machine/md_var.h>
   81 
   82 #define OLD_EI_BRAND    8
   83 
   84 static int __elfN(check_header)(const Elf_Ehdr *hdr);
   85 static Elf_Brandinfo *__elfN(get_brandinfo)(struct image_params *imgp,
   86     const char *interp, int32_t *osrel);
   87 static int __elfN(load_file)(struct proc *p, const char *file, u_long *addr,
   88     u_long *entry, size_t pagesize);
   89 static int __elfN(load_section)(struct vmspace *vmspace, vm_object_t object,
   90     vm_offset_t offset, caddr_t vmaddr, size_t memsz, size_t filsz,
   91     vm_prot_t prot, size_t pagesize);
   92 static int __CONCAT(exec_, __elfN(imgact))(struct image_params *imgp);
   93 static boolean_t __elfN(freebsd_trans_osrel)(const Elf_Note *note,
   94     int32_t *osrel);
   95 static boolean_t kfreebsd_trans_osrel(const Elf_Note *note, int32_t *osrel);
   96 static boolean_t __elfN(check_note)(struct image_params *imgp,
   97     Elf_Brandnote *checknote, int32_t *osrel);
   98 static vm_prot_t __elfN(trans_prot)(Elf_Word);
   99 static Elf_Word __elfN(untrans_prot)(vm_prot_t);
  100 
  101 SYSCTL_NODE(_kern, OID_AUTO, __CONCAT(elf, __ELF_WORD_SIZE), CTLFLAG_RW, 0,
  102     "");
  103 
  104 #ifdef COMPRESS_USER_CORES
  105 static int compress_core(gzFile, char *, char *, unsigned int,
  106     struct thread * td);
  107 #define CORE_BUF_SIZE   (16 * 1024)
  108 #endif
  109 
  110 int __elfN(fallback_brand) = -1;
  111 SYSCTL_INT(__CONCAT(_kern_elf, __ELF_WORD_SIZE), OID_AUTO,
  112     fallback_brand, CTLFLAG_RW, &__elfN(fallback_brand), 0,
  113     __XSTRING(__CONCAT(ELF, __ELF_WORD_SIZE)) " brand of last resort");
  114 TUNABLE_INT("kern.elf" __XSTRING(__ELF_WORD_SIZE) ".fallback_brand",
  115     &__elfN(fallback_brand));
  116 
  117 static int elf_legacy_coredump = 0;
  118 SYSCTL_INT(_debug, OID_AUTO, __elfN(legacy_coredump), CTLFLAG_RW, 
  119     &elf_legacy_coredump, 0, "");
  120 
  121 static int __elfN(nxstack) = 0;
  122 SYSCTL_INT(__CONCAT(_kern_elf, __ELF_WORD_SIZE), OID_AUTO,
  123     nxstack, CTLFLAG_RW, &__elfN(nxstack), 0,
  124     __XSTRING(__CONCAT(ELF, __ELF_WORD_SIZE)) ": enable non-executable stack");
  125 
  126 static Elf_Brandinfo *elf_brand_list[MAX_BRANDS];
  127 
  128 #define trunc_page_ps(va, ps)   ((va) & ~(ps - 1))
  129 #define round_page_ps(va, ps)   (((va) + (ps - 1)) & ~(ps - 1))
  130 #define aligned(a, t)   (trunc_page_ps((u_long)(a), sizeof(t)) == (u_long)(a))
  131 
  132 static const char FREEBSD_ABI_VENDOR[] = "FreeBSD";
  133 
  134 Elf_Brandnote __elfN(freebsd_brandnote) = {
  135         .hdr.n_namesz   = sizeof(FREEBSD_ABI_VENDOR),
  136         .hdr.n_descsz   = sizeof(int32_t),
  137         .hdr.n_type     = 1,
  138         .vendor         = FREEBSD_ABI_VENDOR,
  139         .flags          = BN_TRANSLATE_OSREL,
  140         .trans_osrel    = __elfN(freebsd_trans_osrel)
  141 };
  142 
  143 static boolean_t
  144 __elfN(freebsd_trans_osrel)(const Elf_Note *note, int32_t *osrel)
  145 {
  146         uintptr_t p;
  147 
  148         p = (uintptr_t)(note + 1);
  149         p += roundup2(note->n_namesz, sizeof(Elf32_Addr));
  150         *osrel = *(const int32_t *)(p);
  151 
  152         return (TRUE);
  153 }
  154 
  155 static const char GNU_ABI_VENDOR[] = "GNU";
  156 static int GNU_KFREEBSD_ABI_DESC = 3;
  157 
  158 Elf_Brandnote __elfN(kfreebsd_brandnote) = {
  159         .hdr.n_namesz   = sizeof(GNU_ABI_VENDOR),
  160         .hdr.n_descsz   = 16,   /* XXX at least 16 */
  161         .hdr.n_type     = 1,
  162         .vendor         = GNU_ABI_VENDOR,
  163         .flags          = BN_TRANSLATE_OSREL,
  164         .trans_osrel    = kfreebsd_trans_osrel
  165 };
  166 
  167 static boolean_t
  168 kfreebsd_trans_osrel(const Elf_Note *note, int32_t *osrel)
  169 {
  170         const Elf32_Word *desc;
  171         uintptr_t p;
  172 
  173         p = (uintptr_t)(note + 1);
  174         p += roundup2(note->n_namesz, sizeof(Elf32_Addr));
  175 
  176         desc = (const Elf32_Word *)p;
  177         if (desc[0] != GNU_KFREEBSD_ABI_DESC)
  178                 return (FALSE);
  179 
  180         /*
  181          * Debian GNU/kFreeBSD embed the earliest compatible kernel version
  182          * (__FreeBSD_version: <major><two digit minor>Rxx) in the LSB way.
  183          */
  184         *osrel = desc[1] * 100000 + desc[2] * 1000 + desc[3];
  185 
  186         return (TRUE);
  187 }
  188 
  189 int
  190 __elfN(insert_brand_entry)(Elf_Brandinfo *entry)
  191 {
  192         int i;
  193 
  194         for (i = 0; i < MAX_BRANDS; i++) {
  195                 if (elf_brand_list[i] == NULL) {
  196                         elf_brand_list[i] = entry;
  197                         break;
  198                 }
  199         }
  200         if (i == MAX_BRANDS) {
  201                 printf("WARNING: %s: could not insert brandinfo entry: %p\n",
  202                         __func__, entry);
  203                 return (-1);
  204         }
  205         return (0);
  206 }
  207 
  208 int
  209 __elfN(remove_brand_entry)(Elf_Brandinfo *entry)
  210 {
  211         int i;
  212 
  213         for (i = 0; i < MAX_BRANDS; i++) {
  214                 if (elf_brand_list[i] == entry) {
  215                         elf_brand_list[i] = NULL;
  216                         break;
  217                 }
  218         }
  219         if (i == MAX_BRANDS)
  220                 return (-1);
  221         return (0);
  222 }
  223 
  224 int
  225 __elfN(brand_inuse)(Elf_Brandinfo *entry)
  226 {
  227         struct proc *p;
  228         int rval = FALSE;
  229 
  230         sx_slock(&allproc_lock);
  231         FOREACH_PROC_IN_SYSTEM(p) {
  232                 if (p->p_sysent == entry->sysvec) {
  233                         rval = TRUE;
  234                         break;
  235                 }
  236         }
  237         sx_sunlock(&allproc_lock);
  238 
  239         return (rval);
  240 }
  241 
  242 static Elf_Brandinfo *
  243 __elfN(get_brandinfo)(struct image_params *imgp, const char *interp,
  244     int32_t *osrel)
  245 {
  246         const Elf_Ehdr *hdr = (const Elf_Ehdr *)imgp->image_header;
  247         Elf_Brandinfo *bi;
  248         boolean_t ret;
  249         int i;
  250 
  251         /*
  252          * We support four types of branding -- (1) the ELF EI_OSABI field
  253          * that SCO added to the ELF spec, (2) FreeBSD 3.x's traditional string
  254          * branding w/in the ELF header, (3) path of the `interp_path'
  255          * field, and (4) the ".note.ABI-tag" ELF section.
  256          */
  257 
  258         /* Look for an ".note.ABI-tag" ELF section */
  259         for (i = 0; i < MAX_BRANDS; i++) {
  260                 bi = elf_brand_list[i];
  261                 if (bi == NULL)
  262                         continue;
  263                 if (hdr->e_machine == bi->machine && (bi->flags &
  264                     (BI_BRAND_NOTE|BI_BRAND_NOTE_MANDATORY)) != 0) {
  265                         ret = __elfN(check_note)(imgp, bi->brand_note, osrel);
  266                         if (ret)
  267                                 return (bi);
  268                 }
  269         }
  270 
  271         /* If the executable has a brand, search for it in the brand list. */
  272         for (i = 0; i < MAX_BRANDS; i++) {
  273                 bi = elf_brand_list[i];
  274                 if (bi == NULL || bi->flags & BI_BRAND_NOTE_MANDATORY)
  275                         continue;
  276                 if (hdr->e_machine == bi->machine &&
  277                     (hdr->e_ident[EI_OSABI] == bi->brand ||
  278                     strncmp((const char *)&hdr->e_ident[OLD_EI_BRAND],
  279                     bi->compat_3_brand, strlen(bi->compat_3_brand)) == 0))
  280                         return (bi);
  281         }
  282 
  283         /* Lacking a known brand, search for a recognized interpreter. */
  284         if (interp != NULL) {
  285                 for (i = 0; i < MAX_BRANDS; i++) {
  286                         bi = elf_brand_list[i];
  287                         if (bi == NULL || bi->flags & BI_BRAND_NOTE_MANDATORY)
  288                                 continue;
  289                         if (hdr->e_machine == bi->machine &&
  290                             strcmp(interp, bi->interp_path) == 0)
  291                                 return (bi);
  292                 }
  293         }
  294 
  295         /* Lacking a recognized interpreter, try the default brand */
  296         for (i = 0; i < MAX_BRANDS; i++) {
  297                 bi = elf_brand_list[i];
  298                 if (bi == NULL || bi->flags & BI_BRAND_NOTE_MANDATORY)
  299                         continue;
  300                 if (hdr->e_machine == bi->machine &&
  301                     __elfN(fallback_brand) == bi->brand)
  302                         return (bi);
  303         }
  304         return (NULL);
  305 }
  306 
  307 static int
  308 __elfN(check_header)(const Elf_Ehdr *hdr)
  309 {
  310         Elf_Brandinfo *bi;
  311         int i;
  312 
  313         if (!IS_ELF(*hdr) ||
  314             hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS ||
  315             hdr->e_ident[EI_DATA] != ELF_TARG_DATA ||
  316             hdr->e_ident[EI_VERSION] != EV_CURRENT ||
  317             hdr->e_phentsize != sizeof(Elf_Phdr) ||
  318             hdr->e_version != ELF_TARG_VER)
  319                 return (ENOEXEC);
  320 
  321         /*
  322          * Make sure we have at least one brand for this machine.
  323          */
  324 
  325         for (i = 0; i < MAX_BRANDS; i++) {
  326                 bi = elf_brand_list[i];
  327                 if (bi != NULL && bi->machine == hdr->e_machine)
  328                         break;
  329         }
  330         if (i == MAX_BRANDS)
  331                 return (ENOEXEC);
  332 
  333         return (0);
  334 }
  335 
  336 static int
  337 __elfN(map_partial)(vm_map_t map, vm_object_t object, vm_ooffset_t offset,
  338     vm_offset_t start, vm_offset_t end, vm_prot_t prot)
  339 {
  340         struct sf_buf *sf;
  341         int error;
  342         vm_offset_t off;
  343 
  344         /*
  345          * Create the page if it doesn't exist yet. Ignore errors.
  346          */
  347         vm_map_lock(map);
  348         vm_map_insert(map, NULL, 0, trunc_page(start), round_page(end),
  349             VM_PROT_ALL, VM_PROT_ALL, 0);
  350         vm_map_unlock(map);
  351 
  352         /*
  353          * Find the page from the underlying object.
  354          */
  355         if (object) {
  356                 sf = vm_imgact_map_page(object, offset);
  357                 if (sf == NULL)
  358                         return (KERN_FAILURE);
  359                 off = offset - trunc_page(offset);
  360                 error = copyout((caddr_t)sf_buf_kva(sf) + off, (caddr_t)start,
  361                     end - start);
  362                 vm_imgact_unmap_page(sf);
  363                 if (error) {
  364                         return (KERN_FAILURE);
  365                 }
  366         }
  367 
  368         return (KERN_SUCCESS);
  369 }
  370 
  371 static int
  372 __elfN(map_insert)(vm_map_t map, vm_object_t object, vm_ooffset_t offset,
  373     vm_offset_t start, vm_offset_t end, vm_prot_t prot, int cow)
  374 {
  375         struct sf_buf *sf;
  376         vm_offset_t off;
  377         vm_size_t sz;
  378         int error, rv;
  379 
  380         if (start != trunc_page(start)) {
  381                 rv = __elfN(map_partial)(map, object, offset, start,
  382                     round_page(start), prot);
  383                 if (rv)
  384                         return (rv);
  385                 offset += round_page(start) - start;
  386                 start = round_page(start);
  387         }
  388         if (end != round_page(end)) {
  389                 rv = __elfN(map_partial)(map, object, offset +
  390                     trunc_page(end) - start, trunc_page(end), end, prot);
  391                 if (rv)
  392                         return (rv);
  393                 end = trunc_page(end);
  394         }
  395         if (end > start) {
  396                 if (offset & PAGE_MASK) {
  397                         /*
  398                          * The mapping is not page aligned. This means we have
  399                          * to copy the data. Sigh.
  400                          */
  401                         rv = vm_map_find(map, NULL, 0, &start, end - start,
  402                             FALSE, prot | VM_PROT_WRITE, VM_PROT_ALL, 0);
  403                         if (rv)
  404                                 return (rv);
  405                         if (object == NULL)
  406                                 return (KERN_SUCCESS);
  407                         for (; start < end; start += sz) {
  408                                 sf = vm_imgact_map_page(object, offset);
  409                                 if (sf == NULL)
  410                                         return (KERN_FAILURE);
  411                                 off = offset - trunc_page(offset);
  412                                 sz = end - start;
  413                                 if (sz > PAGE_SIZE - off)
  414                                         sz = PAGE_SIZE - off;
  415                                 error = copyout((caddr_t)sf_buf_kva(sf) + off,
  416                                     (caddr_t)start, sz);
  417                                 vm_imgact_unmap_page(sf);
  418                                 if (error) {
  419                                         return (KERN_FAILURE);
  420                                 }
  421                                 offset += sz;
  422                         }
  423                         rv = KERN_SUCCESS;
  424                 } else {
  425                         vm_object_reference(object);
  426                         vm_map_lock(map);
  427                         rv = vm_map_insert(map, object, offset, start, end,
  428                             prot, VM_PROT_ALL, cow);
  429                         vm_map_unlock(map);
  430                         if (rv != KERN_SUCCESS)
  431                                 vm_object_deallocate(object);
  432                 }
  433                 return (rv);
  434         } else {
  435                 return (KERN_SUCCESS);
  436         }
  437 }
  438 
  439 static int
  440 __elfN(load_section)(struct vmspace *vmspace,
  441         vm_object_t object, vm_offset_t offset,
  442         caddr_t vmaddr, size_t memsz, size_t filsz, vm_prot_t prot,
  443         size_t pagesize)
  444 {
  445         struct sf_buf *sf;
  446         size_t map_len;
  447         vm_offset_t map_addr;
  448         int error, rv, cow;
  449         size_t copy_len;
  450         vm_offset_t file_addr;
  451 
  452         /*
  453          * It's necessary to fail if the filsz + offset taken from the
  454          * header is greater than the actual file pager object's size.
  455          * If we were to allow this, then the vm_map_find() below would
  456          * walk right off the end of the file object and into the ether.
  457          *
  458          * While I'm here, might as well check for something else that
  459          * is invalid: filsz cannot be greater than memsz.
  460          */
  461         if ((off_t)filsz + offset > object->un_pager.vnp.vnp_size ||
  462             filsz > memsz) {
  463                 uprintf("elf_load_section: truncated ELF file\n");
  464                 return (ENOEXEC);
  465         }
  466 
  467         map_addr = trunc_page_ps((vm_offset_t)vmaddr, pagesize);
  468         file_addr = trunc_page_ps(offset, pagesize);
  469 
  470         /*
  471          * We have two choices.  We can either clear the data in the last page
  472          * of an oversized mapping, or we can start the anon mapping a page
  473          * early and copy the initialized data into that first page.  We
  474          * choose the second..
  475          */
  476         if (memsz > filsz)
  477                 map_len = trunc_page_ps(offset + filsz, pagesize) - file_addr;
  478         else
  479                 map_len = round_page_ps(offset + filsz, pagesize) - file_addr;
  480 
  481         if (map_len != 0) {
  482                 /* cow flags: don't dump readonly sections in core */
  483                 cow = MAP_COPY_ON_WRITE | MAP_PREFAULT |
  484                     (prot & VM_PROT_WRITE ? 0 : MAP_DISABLE_COREDUMP);
  485 
  486                 rv = __elfN(map_insert)(&vmspace->vm_map,
  487                                       object,
  488                                       file_addr,        /* file offset */
  489                                       map_addr,         /* virtual start */
  490                                       map_addr + map_len,/* virtual end */
  491                                       prot,
  492                                       cow);
  493                 if (rv != KERN_SUCCESS)
  494                         return (EINVAL);
  495 
  496                 /* we can stop now if we've covered it all */
  497                 if (memsz == filsz) {
  498                         return (0);
  499                 }
  500         }
  501 
  502 
  503         /*
  504          * We have to get the remaining bit of the file into the first part
  505          * of the oversized map segment.  This is normally because the .data
  506          * segment in the file is extended to provide bss.  It's a neat idea
  507          * to try and save a page, but it's a pain in the behind to implement.
  508          */
  509         copy_len = (offset + filsz) - trunc_page_ps(offset + filsz, pagesize);
  510         map_addr = trunc_page_ps((vm_offset_t)vmaddr + filsz, pagesize);
  511         map_len = round_page_ps((vm_offset_t)vmaddr + memsz, pagesize) -
  512             map_addr;
  513 
  514         /* This had damn well better be true! */
  515         if (map_len != 0) {
  516                 rv = __elfN(map_insert)(&vmspace->vm_map, NULL, 0, map_addr,
  517                     map_addr + map_len, VM_PROT_ALL, 0);
  518                 if (rv != KERN_SUCCESS) {
  519                         return (EINVAL);
  520                 }
  521         }
  522 
  523         if (copy_len != 0) {
  524                 vm_offset_t off;
  525 
  526                 sf = vm_imgact_map_page(object, offset + filsz);
  527                 if (sf == NULL)
  528                         return (EIO);
  529 
  530                 /* send the page fragment to user space */
  531                 off = trunc_page_ps(offset + filsz, pagesize) -
  532                     trunc_page(offset + filsz);
  533                 error = copyout((caddr_t)sf_buf_kva(sf) + off,
  534                     (caddr_t)map_addr, copy_len);
  535                 vm_imgact_unmap_page(sf);
  536                 if (error) {
  537                         return (error);
  538                 }
  539         }
  540 
  541         /*
  542          * set it to the specified protection.
  543          * XXX had better undo the damage from pasting over the cracks here!
  544          */
  545         vm_map_protect(&vmspace->vm_map, trunc_page(map_addr),
  546             round_page(map_addr + map_len),  prot, FALSE);
  547 
  548         return (0);
  549 }
  550 
  551 /*
  552  * Load the file "file" into memory.  It may be either a shared object
  553  * or an executable.
  554  *
  555  * The "addr" reference parameter is in/out.  On entry, it specifies
  556  * the address where a shared object should be loaded.  If the file is
  557  * an executable, this value is ignored.  On exit, "addr" specifies
  558  * where the file was actually loaded.
  559  *
  560  * The "entry" reference parameter is out only.  On exit, it specifies
  561  * the entry point for the loaded file.
  562  */
  563 static int
  564 __elfN(load_file)(struct proc *p, const char *file, u_long *addr,
  565         u_long *entry, size_t pagesize)
  566 {
  567         struct {
  568                 struct nameidata nd;
  569                 struct vattr attr;
  570                 struct image_params image_params;
  571         } *tempdata;
  572         const Elf_Ehdr *hdr = NULL;
  573         const Elf_Phdr *phdr = NULL;
  574         struct nameidata *nd;
  575         struct vmspace *vmspace = p->p_vmspace;
  576         struct vattr *attr;
  577         struct image_params *imgp;
  578         vm_prot_t prot;
  579         u_long rbase;
  580         u_long base_addr = 0;
  581         int vfslocked, error, i, numsegs;
  582 
  583 #ifdef CAPABILITY_MODE
  584         /*
  585          * XXXJA: This check can go away once we are sufficiently confident
  586          * that the checks in namei() are correct.
  587          */
  588         if (IN_CAPABILITY_MODE(curthread))
  589                 return (ECAPMODE);
  590 #endif
  591 
  592         tempdata = malloc(sizeof(*tempdata), M_TEMP, M_WAITOK);
  593         nd = &tempdata->nd;
  594         attr = &tempdata->attr;
  595         imgp = &tempdata->image_params;
  596 
  597         /*
  598          * Initialize part of the common data
  599          */
  600         imgp->proc = p;
  601         imgp->attr = attr;
  602         imgp->firstpage = NULL;
  603         imgp->image_header = NULL;
  604         imgp->object = NULL;
  605         imgp->execlabel = NULL;
  606 
  607         NDINIT(nd, LOOKUP, MPSAFE|LOCKLEAF|FOLLOW, UIO_SYSSPACE, file,
  608             curthread);
  609         vfslocked = 0;
  610         if ((error = namei(nd)) != 0) {
  611                 nd->ni_vp = NULL;
  612                 goto fail;
  613         }
  614         vfslocked = NDHASGIANT(nd);
  615         NDFREE(nd, NDF_ONLY_PNBUF);
  616         imgp->vp = nd->ni_vp;
  617 
  618         /*
  619          * Check permissions, modes, uid, etc on the file, and "open" it.
  620          */
  621         error = exec_check_permissions(imgp);
  622         if (error)
  623                 goto fail;
  624 
  625         error = exec_map_first_page(imgp);
  626         if (error)
  627                 goto fail;
  628 
  629         /*
  630          * Also make certain that the interpreter stays the same, so set
  631          * its VV_TEXT flag, too.
  632          */
  633         nd->ni_vp->v_vflag |= VV_TEXT;
  634 
  635         imgp->object = nd->ni_vp->v_object;
  636 
  637         hdr = (const Elf_Ehdr *)imgp->image_header;
  638         if ((error = __elfN(check_header)(hdr)) != 0)
  639                 goto fail;
  640         if (hdr->e_type == ET_DYN)
  641                 rbase = *addr;
  642         else if (hdr->e_type == ET_EXEC)
  643                 rbase = 0;
  644         else {
  645                 error = ENOEXEC;
  646                 goto fail;
  647         }
  648 
  649         /* Only support headers that fit within first page for now      */
  650         /*    (multiplication of two Elf_Half fields will not overflow) */
  651         if ((hdr->e_phoff > PAGE_SIZE) ||
  652             (hdr->e_phentsize * hdr->e_phnum) > PAGE_SIZE - hdr->e_phoff) {
  653                 error = ENOEXEC;
  654                 goto fail;
  655         }
  656 
  657         phdr = (const Elf_Phdr *)(imgp->image_header + hdr->e_phoff);
  658         if (!aligned(phdr, Elf_Addr)) {
  659                 error = ENOEXEC;
  660                 goto fail;
  661         }
  662 
  663         for (i = 0, numsegs = 0; i < hdr->e_phnum; i++) {
  664                 if (phdr[i].p_type == PT_LOAD && phdr[i].p_memsz != 0) {
  665                         /* Loadable segment */
  666                         prot = __elfN(trans_prot)(phdr[i].p_flags);
  667                         if ((error = __elfN(load_section)(vmspace,
  668                             imgp->object, phdr[i].p_offset,
  669                             (caddr_t)(uintptr_t)phdr[i].p_vaddr + rbase,
  670                             phdr[i].p_memsz, phdr[i].p_filesz, prot,
  671                             pagesize)) != 0)
  672                                 goto fail;
  673                         /*
  674                          * Establish the base address if this is the
  675                          * first segment.
  676                          */
  677                         if (numsegs == 0)
  678                                 base_addr = trunc_page(phdr[i].p_vaddr +
  679                                     rbase);
  680                         numsegs++;
  681                 }
  682         }
  683         *addr = base_addr;
  684         *entry = (unsigned long)hdr->e_entry + rbase;
  685 
  686 fail:
  687         if (imgp->firstpage)
  688                 exec_unmap_first_page(imgp);
  689 
  690         if (nd->ni_vp)
  691                 vput(nd->ni_vp);
  692 
  693         VFS_UNLOCK_GIANT(vfslocked);
  694         free(tempdata, M_TEMP);
  695 
  696         return (error);
  697 }
  698 
  699 static int
  700 __CONCAT(exec_, __elfN(imgact))(struct image_params *imgp)
  701 {
  702         const Elf_Ehdr *hdr = (const Elf_Ehdr *)imgp->image_header;
  703         const Elf_Phdr *phdr;
  704         Elf_Auxargs *elf_auxargs;
  705         struct vmspace *vmspace;
  706         vm_prot_t prot;
  707         u_long text_size = 0, data_size = 0, total_size = 0;
  708         u_long text_addr = 0, data_addr = 0;
  709         u_long seg_size, seg_addr;
  710         u_long addr, baddr, et_dyn_addr, entry = 0, proghdr = 0;
  711         int32_t osrel = 0;
  712         int error = 0, i, n;
  713         const char *interp = NULL, *newinterp = NULL;
  714         Elf_Brandinfo *brand_info;
  715         char *path;
  716         struct sysentvec *sv;
  717 
  718         /*
  719          * Do we have a valid ELF header ?
  720          *
  721          * Only allow ET_EXEC & ET_DYN here, reject ET_DYN later
  722          * if particular brand doesn't support it.
  723          */
  724         if (__elfN(check_header)(hdr) != 0 ||
  725             (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN))
  726                 return (-1);
  727 
  728         /*
  729          * From here on down, we return an errno, not -1, as we've
  730          * detected an ELF file.
  731          */
  732 
  733         if ((hdr->e_phoff > PAGE_SIZE) ||
  734             (hdr->e_phoff + hdr->e_phentsize * hdr->e_phnum) > PAGE_SIZE) {
  735                 /* Only support headers in first page for now */
  736                 return (ENOEXEC);
  737         }
  738         phdr = (const Elf_Phdr *)(imgp->image_header + hdr->e_phoff);
  739         if (!aligned(phdr, Elf_Addr))
  740                 return (ENOEXEC);
  741         n = 0;
  742         baddr = 0;
  743         for (i = 0; i < hdr->e_phnum; i++) {
  744                 switch (phdr[i].p_type) {
  745                 case PT_LOAD:
  746                         if (n == 0)
  747                                 baddr = phdr[i].p_vaddr;
  748                         n++;
  749                         break;
  750                 case PT_INTERP:
  751                         /* Path to interpreter */
  752                         if (phdr[i].p_filesz > MAXPATHLEN ||
  753                             phdr[i].p_offset + phdr[i].p_filesz > PAGE_SIZE)
  754                                 return (ENOEXEC);
  755                         interp = imgp->image_header + phdr[i].p_offset;
  756                         break;
  757                 case PT_GNU_STACK:
  758                         if (__elfN(nxstack))
  759                                 imgp->stack_prot =
  760                                     __elfN(trans_prot)(phdr[i].p_flags);
  761                         break;
  762                 }
  763         }
  764 
  765         brand_info = __elfN(get_brandinfo)(imgp, interp, &osrel);
  766         if (brand_info == NULL) {
  767                 uprintf("ELF binary type \"%u\" not known.\n",
  768                     hdr->e_ident[EI_OSABI]);
  769                 return (ENOEXEC);
  770         }
  771         if (hdr->e_type == ET_DYN) {
  772                 if ((brand_info->flags & BI_CAN_EXEC_DYN) == 0)
  773                         return (ENOEXEC);
  774                 /*
  775                  * Honour the base load address from the dso if it is
  776                  * non-zero for some reason.
  777                  */
  778                 if (baddr == 0)
  779                         et_dyn_addr = ET_DYN_LOAD_ADDR;
  780                 else
  781                         et_dyn_addr = 0;
  782         } else
  783                 et_dyn_addr = 0;
  784         sv = brand_info->sysvec;
  785         if (interp != NULL && brand_info->interp_newpath != NULL)
  786                 newinterp = brand_info->interp_newpath;
  787 
  788         /*
  789          * Avoid a possible deadlock if the current address space is destroyed
  790          * and that address space maps the locked vnode.  In the common case,
  791          * the locked vnode's v_usecount is decremented but remains greater
  792          * than zero.  Consequently, the vnode lock is not needed by vrele().
  793          * However, in cases where the vnode lock is external, such as nullfs,
  794          * v_usecount may become zero.
  795          */
  796         VOP_UNLOCK(imgp->vp, 0);
  797 
  798         error = exec_new_vmspace(imgp, sv);
  799         imgp->proc->p_sysent = sv;
  800 
  801         vn_lock(imgp->vp, LK_EXCLUSIVE | LK_RETRY);
  802         if (error)
  803                 return (error);
  804 
  805         vmspace = imgp->proc->p_vmspace;
  806 
  807         for (i = 0; i < hdr->e_phnum; i++) {
  808                 switch (phdr[i].p_type) {
  809                 case PT_LOAD:   /* Loadable segment */
  810                         if (phdr[i].p_memsz == 0)
  811                                 break;
  812                         prot = __elfN(trans_prot)(phdr[i].p_flags);
  813 
  814 #if defined(__ia64__) && __ELF_WORD_SIZE == 32 && defined(IA32_ME_HARDER)
  815                         /*
  816                          * Some x86 binaries assume read == executable,
  817                          * notably the M3 runtime and therefore cvsup
  818                          */
  819                         if (prot & VM_PROT_READ)
  820                                 prot |= VM_PROT_EXECUTE;
  821 #endif
  822 
  823                         if ((error = __elfN(load_section)(vmspace,
  824                             imgp->object, phdr[i].p_offset,
  825                             (caddr_t)(uintptr_t)phdr[i].p_vaddr + et_dyn_addr,
  826                             phdr[i].p_memsz, phdr[i].p_filesz, prot,
  827                             sv->sv_pagesize)) != 0)
  828                                 return (error);
  829 
  830                         /*
  831                          * If this segment contains the program headers,
  832                          * remember their virtual address for the AT_PHDR
  833                          * aux entry. Static binaries don't usually include
  834                          * a PT_PHDR entry.
  835                          */
  836                         if (phdr[i].p_offset == 0 &&
  837                             hdr->e_phoff + hdr->e_phnum * hdr->e_phentsize
  838                                 <= phdr[i].p_filesz)
  839                                 proghdr = phdr[i].p_vaddr + hdr->e_phoff +
  840                                     et_dyn_addr;
  841 
  842                         seg_addr = trunc_page(phdr[i].p_vaddr + et_dyn_addr);
  843                         seg_size = round_page(phdr[i].p_memsz +
  844                             phdr[i].p_vaddr + et_dyn_addr - seg_addr);
  845 
  846                         /*
  847                          * Make the largest executable segment the official
  848                          * text segment and all others data.
  849                          *
  850                          * Note that obreak() assumes that data_addr + 
  851                          * data_size == end of data load area, and the ELF
  852                          * file format expects segments to be sorted by
  853                          * address.  If multiple data segments exist, the
  854                          * last one will be used.
  855                          */
  856 
  857                         if (phdr[i].p_flags & PF_X && text_size < seg_size) {
  858                                 text_size = seg_size;
  859                                 text_addr = seg_addr;
  860                         } else {
  861                                 data_size = seg_size;
  862                                 data_addr = seg_addr;
  863                         }
  864                         total_size += seg_size;
  865                         break;
  866                 case PT_PHDR:   /* Program header table info */
  867                         proghdr = phdr[i].p_vaddr + et_dyn_addr;
  868                         break;
  869                 default:
  870                         break;
  871                 }
  872         }
  873         
  874         if (data_addr == 0 && data_size == 0) {
  875                 data_addr = text_addr;
  876                 data_size = text_size;
  877         }
  878 
  879         entry = (u_long)hdr->e_entry + et_dyn_addr;
  880 
  881         /*
  882          * Check limits.  It should be safe to check the
  883          * limits after loading the segments since we do
  884          * not actually fault in all the segments pages.
  885          */
  886         PROC_LOCK(imgp->proc);
  887         if (data_size > lim_cur(imgp->proc, RLIMIT_DATA) ||
  888             text_size > maxtsiz ||
  889             total_size > lim_cur(imgp->proc, RLIMIT_VMEM) ||
  890             racct_set(imgp->proc, RACCT_DATA, data_size) != 0 ||
  891             racct_set(imgp->proc, RACCT_VMEM, total_size) != 0) {
  892                 PROC_UNLOCK(imgp->proc);
  893                 return (ENOMEM);
  894         }
  895 
  896         vmspace->vm_tsize = text_size >> PAGE_SHIFT;
  897         vmspace->vm_taddr = (caddr_t)(uintptr_t)text_addr;
  898         vmspace->vm_dsize = data_size >> PAGE_SHIFT;
  899         vmspace->vm_daddr = (caddr_t)(uintptr_t)data_addr;
  900 
  901         /*
  902          * We load the dynamic linker where a userland call
  903          * to mmap(0, ...) would put it.  The rationale behind this
  904          * calculation is that it leaves room for the heap to grow to
  905          * its maximum allowed size.
  906          */
  907         addr = round_page((vm_offset_t)imgp->proc->p_vmspace->vm_daddr +
  908             lim_max(imgp->proc, RLIMIT_DATA));
  909         PROC_UNLOCK(imgp->proc);
  910 
  911         imgp->entry_addr = entry;
  912 
  913         if (interp != NULL) {
  914                 int have_interp = FALSE;
  915                 VOP_UNLOCK(imgp->vp, 0);
  916                 if (brand_info->emul_path != NULL &&
  917                     brand_info->emul_path[0] != '\0') {
  918                         path = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
  919                         snprintf(path, MAXPATHLEN, "%s%s",
  920                             brand_info->emul_path, interp);
  921                         error = __elfN(load_file)(imgp->proc, path, &addr,
  922                             &imgp->entry_addr, sv->sv_pagesize);
  923                         free(path, M_TEMP);
  924                         if (error == 0)
  925                                 have_interp = TRUE;
  926                 }
  927                 if (!have_interp && newinterp != NULL) {
  928                         error = __elfN(load_file)(imgp->proc, newinterp, &addr,
  929                             &imgp->entry_addr, sv->sv_pagesize);
  930                         if (error == 0)
  931                                 have_interp = TRUE;
  932                 }
  933                 if (!have_interp) {
  934                         error = __elfN(load_file)(imgp->proc, interp, &addr,
  935                             &imgp->entry_addr, sv->sv_pagesize);
  936                 }
  937                 vn_lock(imgp->vp, LK_EXCLUSIVE | LK_RETRY);
  938                 if (error != 0) {
  939                         uprintf("ELF interpreter %s not found\n", interp);
  940                         return (error);
  941                 }
  942         } else
  943                 addr = et_dyn_addr;
  944 
  945         /*
  946          * Construct auxargs table (used by the fixup routine)
  947          */
  948         elf_auxargs = malloc(sizeof(Elf_Auxargs), M_TEMP, M_WAITOK);
  949         elf_auxargs->execfd = -1;
  950         elf_auxargs->phdr = proghdr;
  951         elf_auxargs->phent = hdr->e_phentsize;
  952         elf_auxargs->phnum = hdr->e_phnum;
  953         elf_auxargs->pagesz = PAGE_SIZE;
  954         elf_auxargs->base = addr;
  955         elf_auxargs->flags = 0;
  956         elf_auxargs->entry = entry;
  957 
  958         imgp->auxargs = elf_auxargs;
  959         imgp->interpreted = 0;
  960         imgp->reloc_base = addr;
  961         imgp->proc->p_osrel = osrel;
  962 
  963         return (error);
  964 }
  965 
  966 #define suword __CONCAT(suword, __ELF_WORD_SIZE)
  967 
  968 int
  969 __elfN(freebsd_fixup)(register_t **stack_base, struct image_params *imgp)
  970 {
  971         Elf_Auxargs *args = (Elf_Auxargs *)imgp->auxargs;
  972         Elf_Addr *base;
  973         Elf_Addr *pos;
  974 
  975         base = (Elf_Addr *)*stack_base;
  976         pos = base + (imgp->args->argc + imgp->args->envc + 2);
  977 
  978         if (args->execfd != -1)
  979                 AUXARGS_ENTRY(pos, AT_EXECFD, args->execfd);
  980         AUXARGS_ENTRY(pos, AT_PHDR, args->phdr);
  981         AUXARGS_ENTRY(pos, AT_PHENT, args->phent);
  982         AUXARGS_ENTRY(pos, AT_PHNUM, args->phnum);
  983         AUXARGS_ENTRY(pos, AT_PAGESZ, args->pagesz);
  984         AUXARGS_ENTRY(pos, AT_FLAGS, args->flags);
  985         AUXARGS_ENTRY(pos, AT_ENTRY, args->entry);
  986         AUXARGS_ENTRY(pos, AT_BASE, args->base);
  987         if (imgp->execpathp != 0)
  988                 AUXARGS_ENTRY(pos, AT_EXECPATH, imgp->execpathp);
  989         AUXARGS_ENTRY(pos, AT_OSRELDATE, osreldate);
  990         if (imgp->canary != 0) {
  991                 AUXARGS_ENTRY(pos, AT_CANARY, imgp->canary);
  992                 AUXARGS_ENTRY(pos, AT_CANARYLEN, imgp->canarylen);
  993         }
  994         AUXARGS_ENTRY(pos, AT_NCPUS, mp_ncpus);
  995         if (imgp->pagesizes != 0) {
  996                 AUXARGS_ENTRY(pos, AT_PAGESIZES, imgp->pagesizes);
  997                 AUXARGS_ENTRY(pos, AT_PAGESIZESLEN, imgp->pagesizeslen);
  998         }
  999         AUXARGS_ENTRY(pos, AT_STACKPROT, imgp->sysent->sv_shared_page_obj
 1000             != NULL && imgp->stack_prot != 0 ? imgp->stack_prot :
 1001             imgp->sysent->sv_stackprot);
 1002         AUXARGS_ENTRY(pos, AT_NULL, 0);
 1003 
 1004         free(imgp->auxargs, M_TEMP);
 1005         imgp->auxargs = NULL;
 1006 
 1007         base--;
 1008         suword(base, (long)imgp->args->argc);
 1009         *stack_base = (register_t *)base;
 1010         return (0);
 1011 }
 1012 
 1013 /*
 1014  * Code for generating ELF core dumps.
 1015  */
 1016 
 1017 typedef void (*segment_callback)(vm_map_entry_t, void *);
 1018 
 1019 /* Closure for cb_put_phdr(). */
 1020 struct phdr_closure {
 1021         Elf_Phdr *phdr;         /* Program header to fill in */
 1022         Elf_Off offset;         /* Offset of segment in core file */
 1023 };
 1024 
 1025 /* Closure for cb_size_segment(). */
 1026 struct sseg_closure {
 1027         int count;              /* Count of writable segments. */
 1028         size_t size;            /* Total size of all writable segments. */
 1029 };
 1030 
 1031 static void cb_put_phdr(vm_map_entry_t, void *);
 1032 static void cb_size_segment(vm_map_entry_t, void *);
 1033 static void each_writable_segment(struct thread *, segment_callback, void *);
 1034 static int __elfN(corehdr)(struct thread *, struct vnode *, struct ucred *,
 1035     int, void *, size_t, gzFile);
 1036 static void __elfN(puthdr)(struct thread *, void *, size_t *, int);
 1037 static void __elfN(putnote)(void *, size_t *, const char *, int,
 1038     const void *, size_t);
 1039 
 1040 #ifdef COMPRESS_USER_CORES
 1041 extern int compress_user_cores;
 1042 extern int compress_user_cores_gzlevel;
 1043 #endif
 1044 
 1045 static int
 1046 core_output(struct vnode *vp, void *base, size_t len, off_t offset,
 1047     struct ucred *active_cred, struct ucred *file_cred,
 1048     struct thread *td, char *core_buf, gzFile gzfile) {
 1049 
 1050         int error;
 1051         if (gzfile) {
 1052 #ifdef COMPRESS_USER_CORES
 1053                 error = compress_core(gzfile, base, core_buf, len, td);
 1054 #else
 1055                 panic("shouldn't be here");
 1056 #endif
 1057         } else {
 1058                 error = vn_rdwr_inchunks(UIO_WRITE, vp, base, len, offset,
 1059                     UIO_USERSPACE, IO_UNIT | IO_DIRECT, active_cred, file_cred,
 1060                     NULL, td);
 1061         }
 1062         return (error);
 1063 }
 1064 
 1065 int
 1066 __elfN(coredump)(struct thread *td, struct vnode *vp, off_t limit, int flags)
 1067 {
 1068         struct ucred *cred = td->td_ucred;
 1069         int error = 0;
 1070         struct sseg_closure seginfo;
 1071         void *hdr;
 1072         size_t hdrsize;
 1073 
 1074         gzFile gzfile = Z_NULL;
 1075         char *core_buf = NULL;
 1076 #ifdef COMPRESS_USER_CORES
 1077         char gzopen_flags[8];
 1078         char *p;
 1079         int doing_compress = flags & IMGACT_CORE_COMPRESS;
 1080 #endif
 1081 
 1082         hdr = NULL;
 1083 
 1084 #ifdef COMPRESS_USER_CORES
 1085         if (doing_compress) {
 1086                 p = gzopen_flags;
 1087                 *p++ = 'w';
 1088                 if (compress_user_cores_gzlevel >= 0 &&
 1089                     compress_user_cores_gzlevel <= 9)
 1090                         *p++ = '' + compress_user_cores_gzlevel;
 1091                 *p = 0;
 1092                 gzfile = gz_open("", gzopen_flags, vp);
 1093                 if (gzfile == Z_NULL) {
 1094                         error = EFAULT;
 1095                         goto done;
 1096                 }
 1097                 core_buf = malloc(CORE_BUF_SIZE, M_TEMP, M_WAITOK | M_ZERO);
 1098                 if (!core_buf) {
 1099                         error = ENOMEM;
 1100                         goto done;
 1101                 }
 1102         }
 1103 #endif
 1104 
 1105         /* Size the program segments. */
 1106         seginfo.count = 0;
 1107         seginfo.size = 0;
 1108         each_writable_segment(td, cb_size_segment, &seginfo);
 1109 
 1110         /*
 1111          * Calculate the size of the core file header area by making
 1112          * a dry run of generating it.  Nothing is written, but the
 1113          * size is calculated.
 1114          */
 1115         hdrsize = 0;
 1116         __elfN(puthdr)(td, (void *)NULL, &hdrsize, seginfo.count);
 1117 
 1118 #ifdef RACCT
 1119         PROC_LOCK(td->td_proc);
 1120         error = racct_add(td->td_proc, RACCT_CORE, hdrsize + seginfo.size);
 1121         PROC_UNLOCK(td->td_proc);
 1122         if (error != 0) {
 1123                 error = EFAULT;
 1124                 goto done;
 1125         }
 1126 #endif
 1127         if (hdrsize + seginfo.size >= limit) {
 1128                 error = EFAULT;
 1129                 goto done;
 1130         }
 1131 
 1132         /*
 1133          * Allocate memory for building the header, fill it up,
 1134          * and write it out.
 1135          */
 1136         hdr = malloc(hdrsize, M_TEMP, M_WAITOK);
 1137         if (hdr == NULL) {
 1138                 error = EINVAL;
 1139                 goto done;
 1140         }
 1141         error = __elfN(corehdr)(td, vp, cred, seginfo.count, hdr, hdrsize,
 1142             gzfile);
 1143 
 1144         /* Write the contents of all of the writable segments. */
 1145         if (error == 0) {
 1146                 Elf_Phdr *php;
 1147                 off_t offset;
 1148                 int i;
 1149 
 1150                 php = (Elf_Phdr *)((char *)hdr + sizeof(Elf_Ehdr)) + 1;
 1151                 offset = hdrsize;
 1152                 for (i = 0; i < seginfo.count; i++) {
 1153                         error = core_output(vp, (caddr_t)(uintptr_t)php->p_vaddr,
 1154                             php->p_filesz, offset, cred, NOCRED, curthread, core_buf, gzfile);
 1155                         if (error != 0)
 1156                                 break;
 1157                         offset += php->p_filesz;
 1158                         php++;
 1159                 }
 1160         }
 1161         if (error) {
 1162                 log(LOG_WARNING,
 1163                     "Failed to write core file for process %s (error %d)\n",
 1164                     curproc->p_comm, error);
 1165         }
 1166 
 1167 done:
 1168 #ifdef COMPRESS_USER_CORES
 1169         if (core_buf)
 1170                 free(core_buf, M_TEMP);
 1171         if (gzfile)
 1172                 gzclose(gzfile);
 1173 #endif
 1174 
 1175         free(hdr, M_TEMP);
 1176 
 1177         return (error);
 1178 }
 1179 
 1180 /*
 1181  * A callback for each_writable_segment() to write out the segment's
 1182  * program header entry.
 1183  */
 1184 static void
 1185 cb_put_phdr(entry, closure)
 1186         vm_map_entry_t entry;
 1187         void *closure;
 1188 {
 1189         struct phdr_closure *phc = (struct phdr_closure *)closure;
 1190         Elf_Phdr *phdr = phc->phdr;
 1191 
 1192         phc->offset = round_page(phc->offset);
 1193 
 1194         phdr->p_type = PT_LOAD;
 1195         phdr->p_offset = phc->offset;
 1196         phdr->p_vaddr = entry->start;
 1197         phdr->p_paddr = 0;
 1198         phdr->p_filesz = phdr->p_memsz = entry->end - entry->start;
 1199         phdr->p_align = PAGE_SIZE;
 1200         phdr->p_flags = __elfN(untrans_prot)(entry->protection);
 1201 
 1202         phc->offset += phdr->p_filesz;
 1203         phc->phdr++;
 1204 }
 1205 
 1206 /*
 1207  * A callback for each_writable_segment() to gather information about
 1208  * the number of segments and their total size.
 1209  */
 1210 static void
 1211 cb_size_segment(entry, closure)
 1212         vm_map_entry_t entry;
 1213         void *closure;
 1214 {
 1215         struct sseg_closure *ssc = (struct sseg_closure *)closure;
 1216 
 1217         ssc->count++;
 1218         ssc->size += entry->end - entry->start;
 1219 }
 1220 
 1221 /*
 1222  * For each writable segment in the process's memory map, call the given
 1223  * function with a pointer to the map entry and some arbitrary
 1224  * caller-supplied data.
 1225  */
 1226 static void
 1227 each_writable_segment(td, func, closure)
 1228         struct thread *td;
 1229         segment_callback func;
 1230         void *closure;
 1231 {
 1232         struct proc *p = td->td_proc;
 1233         vm_map_t map = &p->p_vmspace->vm_map;
 1234         vm_map_entry_t entry;
 1235         vm_object_t backing_object, object;
 1236         boolean_t ignore_entry;
 1237 
 1238         vm_map_lock_read(map);
 1239         for (entry = map->header.next; entry != &map->header;
 1240             entry = entry->next) {
 1241                 /*
 1242                  * Don't dump inaccessible mappings, deal with legacy
 1243                  * coredump mode.
 1244                  *
 1245                  * Note that read-only segments related to the elf binary
 1246                  * are marked MAP_ENTRY_NOCOREDUMP now so we no longer
 1247                  * need to arbitrarily ignore such segments.
 1248                  */
 1249                 if (elf_legacy_coredump) {
 1250                         if ((entry->protection & VM_PROT_RW) != VM_PROT_RW)
 1251                                 continue;
 1252                 } else {
 1253                         if ((entry->protection & VM_PROT_ALL) == 0)
 1254                                 continue;
 1255                 }
 1256 
 1257                 /*
 1258                  * Dont include memory segment in the coredump if
 1259                  * MAP_NOCORE is set in mmap(2) or MADV_NOCORE in
 1260                  * madvise(2).  Do not dump submaps (i.e. parts of the
 1261                  * kernel map).
 1262                  */
 1263                 if (entry->eflags & (MAP_ENTRY_NOCOREDUMP|MAP_ENTRY_IS_SUB_MAP))
 1264                         continue;
 1265 
 1266                 if ((object = entry->object.vm_object) == NULL)
 1267                         continue;
 1268 
 1269                 /* Ignore memory-mapped devices and such things. */
 1270                 VM_OBJECT_LOCK(object);
 1271                 while ((backing_object = object->backing_object) != NULL) {
 1272                         VM_OBJECT_LOCK(backing_object);
 1273                         VM_OBJECT_UNLOCK(object);
 1274                         object = backing_object;
 1275                 }
 1276                 ignore_entry = object->type != OBJT_DEFAULT &&
 1277                     object->type != OBJT_SWAP && object->type != OBJT_VNODE;
 1278                 VM_OBJECT_UNLOCK(object);
 1279                 if (ignore_entry)
 1280                         continue;
 1281 
 1282                 (*func)(entry, closure);
 1283         }
 1284         vm_map_unlock_read(map);
 1285 }
 1286 
 1287 /*
 1288  * Write the core file header to the file, including padding up to
 1289  * the page boundary.
 1290  */
 1291 static int
 1292 __elfN(corehdr)(td, vp, cred, numsegs, hdr, hdrsize, gzfile)
 1293         struct thread *td;
 1294         struct vnode *vp;
 1295         struct ucred *cred;
 1296         int numsegs;
 1297         size_t hdrsize;
 1298         void *hdr;
 1299         gzFile gzfile;
 1300 {
 1301         size_t off;
 1302 
 1303         /* Fill in the header. */
 1304         bzero(hdr, hdrsize);
 1305         off = 0;
 1306         __elfN(puthdr)(td, hdr, &off, numsegs);
 1307 
 1308         if (!gzfile) {
 1309                 /* Write it to the core file. */
 1310                 return (vn_rdwr_inchunks(UIO_WRITE, vp, hdr, hdrsize, (off_t)0,
 1311                         UIO_SYSSPACE, IO_UNIT | IO_DIRECT, cred, NOCRED, NULL,
 1312                         td));
 1313         } else {
 1314 #ifdef COMPRESS_USER_CORES
 1315                 if (gzwrite(gzfile, hdr, hdrsize) != hdrsize) {
 1316                         log(LOG_WARNING,
 1317                             "Failed to compress core file header for process"
 1318                             " %s.\n", curproc->p_comm);
 1319                         return (EFAULT);
 1320                 }
 1321                 else {
 1322                         return (0);
 1323                 }
 1324 #else
 1325                 panic("shouldn't be here");
 1326 #endif
 1327         }
 1328 }
 1329 
 1330 #if defined(COMPAT_FREEBSD32) && __ELF_WORD_SIZE == 32
 1331 #include <compat/freebsd32/freebsd32.h>
 1332 
 1333 typedef struct prstatus32 elf_prstatus_t;
 1334 typedef struct prpsinfo32 elf_prpsinfo_t;
 1335 typedef struct fpreg32 elf_prfpregset_t;
 1336 typedef struct fpreg32 elf_fpregset_t;
 1337 typedef struct reg32 elf_gregset_t;
 1338 typedef struct thrmisc32 elf_thrmisc_t;
 1339 #else
 1340 typedef prstatus_t elf_prstatus_t;
 1341 typedef prpsinfo_t elf_prpsinfo_t;
 1342 typedef prfpregset_t elf_prfpregset_t;
 1343 typedef prfpregset_t elf_fpregset_t;
 1344 typedef gregset_t elf_gregset_t;
 1345 typedef thrmisc_t elf_thrmisc_t;
 1346 #endif
 1347 
 1348 static void
 1349 __elfN(puthdr)(struct thread *td, void *dst, size_t *off, int numsegs)
 1350 {
 1351         struct {
 1352                 elf_prstatus_t status;
 1353                 elf_prfpregset_t fpregset;
 1354                 elf_prpsinfo_t psinfo;
 1355                 elf_thrmisc_t thrmisc;
 1356         } *tempdata;
 1357         elf_prstatus_t *status;
 1358         elf_prfpregset_t *fpregset;
 1359         elf_prpsinfo_t *psinfo;
 1360         elf_thrmisc_t *thrmisc;
 1361         struct proc *p;
 1362         struct thread *thr;
 1363         size_t ehoff, noteoff, notesz, phoff;
 1364 
 1365         p = td->td_proc;
 1366 
 1367         ehoff = *off;
 1368         *off += sizeof(Elf_Ehdr);
 1369 
 1370         phoff = *off;
 1371         *off += (numsegs + 1) * sizeof(Elf_Phdr);
 1372 
 1373         noteoff = *off;
 1374         /*
 1375          * Don't allocate space for the notes if we're just calculating
 1376          * the size of the header. We also don't collect the data.
 1377          */
 1378         if (dst != NULL) {
 1379                 tempdata = malloc(sizeof(*tempdata), M_TEMP, M_ZERO|M_WAITOK);
 1380                 status = &tempdata->status;
 1381                 fpregset = &tempdata->fpregset;
 1382                 psinfo = &tempdata->psinfo;
 1383                 thrmisc = &tempdata->thrmisc;
 1384         } else {
 1385                 tempdata = NULL;
 1386                 status = NULL;
 1387                 fpregset = NULL;
 1388                 psinfo = NULL;
 1389                 thrmisc = NULL;
 1390         }
 1391 
 1392         if (dst != NULL) {
 1393                 psinfo->pr_version = PRPSINFO_VERSION;
 1394                 psinfo->pr_psinfosz = sizeof(elf_prpsinfo_t);
 1395                 strlcpy(psinfo->pr_fname, p->p_comm, sizeof(psinfo->pr_fname));
 1396                 /*
 1397                  * XXX - We don't fill in the command line arguments properly
 1398                  * yet.
 1399                  */
 1400                 strlcpy(psinfo->pr_psargs, p->p_comm,
 1401                     sizeof(psinfo->pr_psargs));
 1402         }
 1403         __elfN(putnote)(dst, off, "FreeBSD", NT_PRPSINFO, psinfo,
 1404             sizeof *psinfo);
 1405 
 1406         /*
 1407          * To have the debugger select the right thread (LWP) as the initial
 1408          * thread, we dump the state of the thread passed to us in td first.
 1409          * This is the thread that causes the core dump and thus likely to
 1410          * be the right thread one wants to have selected in the debugger.
 1411          */
 1412         thr = td;
 1413         while (thr != NULL) {
 1414                 if (dst != NULL) {
 1415                         status->pr_version = PRSTATUS_VERSION;
 1416                         status->pr_statussz = sizeof(elf_prstatus_t);
 1417                         status->pr_gregsetsz = sizeof(elf_gregset_t);
 1418                         status->pr_fpregsetsz = sizeof(elf_fpregset_t);
 1419                         status->pr_osreldate = osreldate;
 1420                         status->pr_cursig = p->p_sig;
 1421                         status->pr_pid = thr->td_tid;
 1422 #if defined(COMPAT_FREEBSD32) && __ELF_WORD_SIZE == 32
 1423                         fill_regs32(thr, &status->pr_reg);
 1424                         fill_fpregs32(thr, fpregset);
 1425 #else
 1426                         fill_regs(thr, &status->pr_reg);
 1427                         fill_fpregs(thr, fpregset);
 1428 #endif
 1429                         memset(&thrmisc->_pad, 0, sizeof (thrmisc->_pad));
 1430                         strcpy(thrmisc->pr_tname, thr->td_name);
 1431                 }
 1432                 __elfN(putnote)(dst, off, "FreeBSD", NT_PRSTATUS, status,
 1433                     sizeof *status);
 1434                 __elfN(putnote)(dst, off, "FreeBSD", NT_FPREGSET, fpregset,
 1435                     sizeof *fpregset);
 1436                 __elfN(putnote)(dst, off, "FreeBSD", NT_THRMISC, thrmisc,
 1437                     sizeof *thrmisc);
 1438                 /*
 1439                  * Allow for MD specific notes, as well as any MD
 1440                  * specific preparations for writing MI notes.
 1441                  */
 1442                 __elfN(dump_thread)(thr, dst, off);
 1443 
 1444                 thr = (thr == td) ? TAILQ_FIRST(&p->p_threads) :
 1445                     TAILQ_NEXT(thr, td_plist);
 1446                 if (thr == td)
 1447                         thr = TAILQ_NEXT(thr, td_plist);
 1448         }
 1449 
 1450         notesz = *off - noteoff;
 1451 
 1452         if (dst != NULL)
 1453                 free(tempdata, M_TEMP);
 1454 
 1455         /* Align up to a page boundary for the program segments. */
 1456         *off = round_page(*off);
 1457 
 1458         if (dst != NULL) {
 1459                 Elf_Ehdr *ehdr;
 1460                 Elf_Phdr *phdr;
 1461                 struct phdr_closure phc;
 1462 
 1463                 /*
 1464                  * Fill in the ELF header.
 1465                  */
 1466                 ehdr = (Elf_Ehdr *)((char *)dst + ehoff);
 1467                 ehdr->e_ident[EI_MAG0] = ELFMAG0;
 1468                 ehdr->e_ident[EI_MAG1] = ELFMAG1;
 1469                 ehdr->e_ident[EI_MAG2] = ELFMAG2;
 1470                 ehdr->e_ident[EI_MAG3] = ELFMAG3;
 1471                 ehdr->e_ident[EI_CLASS] = ELF_CLASS;
 1472                 ehdr->e_ident[EI_DATA] = ELF_DATA;
 1473                 ehdr->e_ident[EI_VERSION] = EV_CURRENT;
 1474                 ehdr->e_ident[EI_OSABI] = ELFOSABI_FREEBSD;
 1475                 ehdr->e_ident[EI_ABIVERSION] = 0;
 1476                 ehdr->e_ident[EI_PAD] = 0;
 1477                 ehdr->e_type = ET_CORE;
 1478 #if defined(COMPAT_FREEBSD32) && __ELF_WORD_SIZE == 32
 1479                 ehdr->e_machine = ELF_ARCH32;
 1480 #else
 1481                 ehdr->e_machine = ELF_ARCH;
 1482 #endif
 1483                 ehdr->e_version = EV_CURRENT;
 1484                 ehdr->e_entry = 0;
 1485                 ehdr->e_phoff = phoff;
 1486                 ehdr->e_flags = 0;
 1487                 ehdr->e_ehsize = sizeof(Elf_Ehdr);
 1488                 ehdr->e_phentsize = sizeof(Elf_Phdr);
 1489                 ehdr->e_phnum = numsegs + 1;
 1490                 ehdr->e_shentsize = sizeof(Elf_Shdr);
 1491                 ehdr->e_shnum = 0;
 1492                 ehdr->e_shstrndx = SHN_UNDEF;
 1493 
 1494                 /*
 1495                  * Fill in the program header entries.
 1496                  */
 1497                 phdr = (Elf_Phdr *)((char *)dst + phoff);
 1498 
 1499                 /* The note segement. */
 1500                 phdr->p_type = PT_NOTE;
 1501                 phdr->p_offset = noteoff;
 1502                 phdr->p_vaddr = 0;
 1503                 phdr->p_paddr = 0;
 1504                 phdr->p_filesz = notesz;
 1505                 phdr->p_memsz = 0;
 1506                 phdr->p_flags = 0;
 1507                 phdr->p_align = 0;
 1508                 phdr++;
 1509 
 1510                 /* All the writable segments from the program. */
 1511                 phc.phdr = phdr;
 1512                 phc.offset = *off;
 1513                 each_writable_segment(td, cb_put_phdr, &phc);
 1514         }
 1515 }
 1516 
 1517 static void
 1518 __elfN(putnote)(void *dst, size_t *off, const char *name, int type,
 1519     const void *desc, size_t descsz)
 1520 {
 1521         Elf_Note note;
 1522 
 1523         note.n_namesz = strlen(name) + 1;
 1524         note.n_descsz = descsz;
 1525         note.n_type = type;
 1526         if (dst != NULL)
 1527                 bcopy(&note, (char *)dst + *off, sizeof note);
 1528         *off += sizeof note;
 1529         if (dst != NULL)
 1530                 bcopy(name, (char *)dst + *off, note.n_namesz);
 1531         *off += roundup2(note.n_namesz, sizeof(Elf_Size));
 1532         if (dst != NULL)
 1533                 bcopy(desc, (char *)dst + *off, note.n_descsz);
 1534         *off += roundup2(note.n_descsz, sizeof(Elf_Size));
 1535 }
 1536 
 1537 /*
 1538  * Try to find the appropriate ABI-note section for checknote,
 1539  * fetch the osreldate for binary from the ELF OSABI-note. Only the
 1540  * first page of the image is searched, the same as for headers.
 1541  */
 1542 static boolean_t
 1543 __elfN(check_note)(struct image_params *imgp, Elf_Brandnote *checknote,
 1544     int32_t *osrel)
 1545 {
 1546         const Elf_Note *note, *note0, *note_end;
 1547         const Elf_Phdr *phdr, *pnote;
 1548         const Elf_Ehdr *hdr;
 1549         const char *note_name;
 1550         int i;
 1551 
 1552         pnote = NULL;
 1553         hdr = (const Elf_Ehdr *)imgp->image_header;
 1554         phdr = (const Elf_Phdr *)(imgp->image_header + hdr->e_phoff);
 1555 
 1556         for (i = 0; i < hdr->e_phnum; i++) {
 1557                 if (phdr[i].p_type == PT_NOTE) {
 1558                         pnote = &phdr[i];
 1559                         break;
 1560                 }
 1561         }
 1562 
 1563         if (pnote == NULL || pnote->p_offset >= PAGE_SIZE ||
 1564             pnote->p_offset + pnote->p_filesz >= PAGE_SIZE)
 1565                 return (FALSE);
 1566 
 1567         note = note0 = (const Elf_Note *)(imgp->image_header + pnote->p_offset);
 1568         note_end = (const Elf_Note *)(imgp->image_header +
 1569             pnote->p_offset + pnote->p_filesz);
 1570         for (i = 0; i < 100 && note >= note0 && note < note_end; i++) {
 1571                 if (!aligned(note, Elf32_Addr))
 1572                         return (FALSE);
 1573                 if (note->n_namesz != checknote->hdr.n_namesz ||
 1574                     note->n_descsz != checknote->hdr.n_descsz ||
 1575                     note->n_type != checknote->hdr.n_type)
 1576                         goto nextnote;
 1577                 note_name = (const char *)(note + 1);
 1578                 if (strncmp(checknote->vendor, note_name,
 1579                     checknote->hdr.n_namesz) != 0)
 1580                         goto nextnote;
 1581 
 1582                 /*
 1583                  * Fetch the osreldate for binary
 1584                  * from the ELF OSABI-note if necessary.
 1585                  */
 1586                 if ((checknote->flags & BN_TRANSLATE_OSREL) != 0 &&
 1587                     checknote->trans_osrel != NULL)
 1588                         return (checknote->trans_osrel(note, osrel));
 1589                 return (TRUE);
 1590 
 1591 nextnote:
 1592                 note = (const Elf_Note *)((const char *)(note + 1) +
 1593                     roundup2(note->n_namesz, sizeof(Elf32_Addr)) +
 1594                     roundup2(note->n_descsz, sizeof(Elf32_Addr)));
 1595         }
 1596 
 1597         return (FALSE);
 1598 }
 1599 
 1600 /*
 1601  * Tell kern_execve.c about it, with a little help from the linker.
 1602  */
 1603 static struct execsw __elfN(execsw) = {
 1604         __CONCAT(exec_, __elfN(imgact)),
 1605         __XSTRING(__CONCAT(ELF, __ELF_WORD_SIZE))
 1606 };
 1607 EXEC_SET(__CONCAT(elf, __ELF_WORD_SIZE), __elfN(execsw));
 1608 
 1609 #ifdef COMPRESS_USER_CORES
 1610 /*
 1611  * Compress and write out a core segment for a user process.
 1612  *
 1613  * 'inbuf' is the starting address of a VM segment in the process' address
 1614  * space that is to be compressed and written out to the core file.  'dest_buf'
 1615  * is a buffer in the kernel's address space.  The segment is copied from 
 1616  * 'inbuf' to 'dest_buf' first before being processed by the compression
 1617  * routine gzwrite().  This copying is necessary because the content of the VM
 1618  * segment may change between the compression pass and the crc-computation pass
 1619  * in gzwrite().  This is because realtime threads may preempt the UNIX kernel.
 1620  */
 1621 static int
 1622 compress_core (gzFile file, char *inbuf, char *dest_buf, unsigned int len,
 1623     struct thread *td)
 1624 {
 1625         int len_compressed;
 1626         int error = 0;
 1627         unsigned int chunk_len;
 1628 
 1629         while (len) {
 1630                 chunk_len = (len > CORE_BUF_SIZE) ? CORE_BUF_SIZE : len;
 1631                 copyin(inbuf, dest_buf, chunk_len);
 1632                 len_compressed = gzwrite(file, dest_buf, chunk_len);
 1633 
 1634                 EVENTHANDLER_INVOKE(app_coredump_progress, td, len_compressed);
 1635 
 1636                 if ((unsigned int)len_compressed != chunk_len) {
 1637                         log(LOG_WARNING,
 1638                             "compress_core: length mismatch (0x%x returned, "
 1639                             "0x%x expected)\n", len_compressed, chunk_len);
 1640                         EVENTHANDLER_INVOKE(app_coredump_error, td,
 1641                             "compress_core: length mismatch %x -> %x",
 1642                             chunk_len, len_compressed);
 1643                         error = EFAULT;
 1644                         break;
 1645                 }
 1646                 inbuf += chunk_len;
 1647                 len -= chunk_len;
 1648                 maybe_yield();
 1649         }
 1650 
 1651         return (error);
 1652 }
 1653 #endif /* COMPRESS_USER_CORES */
 1654 
 1655 static vm_prot_t
 1656 __elfN(trans_prot)(Elf_Word flags)
 1657 {
 1658         vm_prot_t prot;
 1659 
 1660         prot = 0;
 1661         if (flags & PF_X)
 1662                 prot |= VM_PROT_EXECUTE;
 1663         if (flags & PF_W)
 1664                 prot |= VM_PROT_WRITE;
 1665         if (flags & PF_R)
 1666                 prot |= VM_PROT_READ;
 1667         return (prot);
 1668 }
 1669 
 1670 static Elf_Word
 1671 __elfN(untrans_prot)(vm_prot_t prot)
 1672 {
 1673         Elf_Word flags;
 1674 
 1675         flags = 0;
 1676         if (prot & VM_PROT_EXECUTE)
 1677                 flags |= PF_X;
 1678         if (prot & VM_PROT_READ)
 1679                 flags |= PF_R;
 1680         if (prot & VM_PROT_WRITE)
 1681                 flags |= PF_W;
 1682         return (flags);
 1683 }

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