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


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FreeBSD/Linux Kernel Cross Reference
sys/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/6.4/sys/kern/imgact_elf.c 174408 2007-12-07 14:30:26Z kib $");
   33 
   34 #include "opt_compat.h"
   35 
   36 #include <sys/param.h>
   37 #include <sys/exec.h>
   38 #include <sys/fcntl.h>
   39 #include <sys/imgact.h>
   40 #include <sys/imgact_elf.h>
   41 #include <sys/kernel.h>
   42 #include <sys/lock.h>
   43 #include <sys/malloc.h>
   44 #include <sys/mount.h>
   45 #include <sys/mutex.h>
   46 #include <sys/mman.h>
   47 #include <sys/namei.h>
   48 #include <sys/pioctl.h>
   49 #include <sys/proc.h>
   50 #include <sys/procfs.h>
   51 #include <sys/resourcevar.h>
   52 #include <sys/sf_buf.h>
   53 #include <sys/systm.h>
   54 #include <sys/signalvar.h>
   55 #include <sys/stat.h>
   56 #include <sys/sx.h>
   57 #include <sys/syscall.h>
   58 #include <sys/sysctl.h>
   59 #include <sys/sysent.h>
   60 #include <sys/vnode.h>
   61 
   62 #include <vm/vm.h>
   63 #include <vm/vm_kern.h>
   64 #include <vm/vm_param.h>
   65 #include <vm/pmap.h>
   66 #include <vm/vm_map.h>
   67 #include <vm/vm_object.h>
   68 #include <vm/vm_extern.h>
   69 
   70 #include <machine/elf.h>
   71 #include <machine/md_var.h>
   72 
   73 #if defined(COMPAT_IA32) && __ELF_WORD_SIZE == 32
   74 #include <machine/fpu.h>
   75 #include <compat/ia32/ia32_reg.h>
   76 #endif
   77 
   78 #define OLD_EI_BRAND    8
   79 
   80 static int __elfN(check_header)(const Elf_Ehdr *hdr);
   81 static Elf_Brandinfo *__elfN(get_brandinfo)(const Elf_Ehdr *hdr,
   82     const char *interp);
   83 static int __elfN(load_file)(struct proc *p, const char *file, u_long *addr,
   84     u_long *entry, size_t pagesize);
   85 static int __elfN(load_section)(struct vmspace *vmspace, vm_object_t object,
   86     vm_offset_t offset, caddr_t vmaddr, size_t memsz, size_t filsz,
   87     vm_prot_t prot, size_t pagesize);
   88 static int __CONCAT(exec_, __elfN(imgact))(struct image_params *imgp);
   89 
   90 SYSCTL_NODE(_kern, OID_AUTO, __CONCAT(elf, __ELF_WORD_SIZE), CTLFLAG_RW, 0,
   91     "");
   92 
   93 int __elfN(fallback_brand) = -1;
   94 SYSCTL_INT(__CONCAT(_kern_elf, __ELF_WORD_SIZE), OID_AUTO,
   95     fallback_brand, CTLFLAG_RW, &__elfN(fallback_brand), 0,
   96     __XSTRING(__CONCAT(ELF, __ELF_WORD_SIZE)) " brand of last resort");
   97 TUNABLE_INT("kern.elf" __XSTRING(__ELF_WORD_SIZE) ".fallback_brand",
   98     &__elfN(fallback_brand));
   99 
  100 static int elf_trace = 0;
  101 SYSCTL_INT(_debug, OID_AUTO, __elfN(trace), CTLFLAG_RW, &elf_trace, 0, "");
  102 
  103 static int elf_legacy_coredump = 0;
  104 SYSCTL_INT(_debug, OID_AUTO, __elfN(legacy_coredump), CTLFLAG_RW, 
  105     &elf_legacy_coredump, 0, "");
  106 
  107 static Elf_Brandinfo *elf_brand_list[MAX_BRANDS];
  108 
  109 #define trunc_page_ps(va, ps)   ((va) & ~(ps - 1))
  110 #define round_page_ps(va, ps)   (((va) + (ps - 1)) & ~(ps - 1))
  111 #define aligned(a, t)   (trunc_page_ps((u_long)(a), sizeof(t)) == (u_long)(a))
  112 
  113 int
  114 __elfN(insert_brand_entry)(Elf_Brandinfo *entry)
  115 {
  116         int i;
  117 
  118         for (i = 0; i < MAX_BRANDS; i++) {
  119                 if (elf_brand_list[i] == NULL) {
  120                         elf_brand_list[i] = entry;
  121                         break;
  122                 }
  123         }
  124         if (i == MAX_BRANDS)
  125                 return (-1);
  126         return (0);
  127 }
  128 
  129 int
  130 __elfN(remove_brand_entry)(Elf_Brandinfo *entry)
  131 {
  132         int i;
  133 
  134         for (i = 0; i < MAX_BRANDS; i++) {
  135                 if (elf_brand_list[i] == entry) {
  136                         elf_brand_list[i] = NULL;
  137                         break;
  138                 }
  139         }
  140         if (i == MAX_BRANDS)
  141                 return (-1);
  142         return (0);
  143 }
  144 
  145 int
  146 __elfN(brand_inuse)(Elf_Brandinfo *entry)
  147 {
  148         struct proc *p;
  149         int rval = FALSE;
  150 
  151         sx_slock(&allproc_lock);
  152         LIST_FOREACH(p, &allproc, p_list) {
  153                 if (p->p_sysent == entry->sysvec) {
  154                         rval = TRUE;
  155                         break;
  156                 }
  157         }
  158         sx_sunlock(&allproc_lock);
  159 
  160         return (rval);
  161 }
  162 
  163 static Elf_Brandinfo *
  164 __elfN(get_brandinfo)(const Elf_Ehdr *hdr, const char *interp)
  165 {
  166         Elf_Brandinfo *bi;
  167         int i;
  168 
  169         /*
  170          * We support three types of branding -- (1) the ELF EI_OSABI field
  171          * that SCO added to the ELF spec, (2) FreeBSD 3.x's traditional string
  172          * branding w/in the ELF header, and (3) path of the `interp_path'
  173          * field.  We should also look for an ".note.ABI-tag" ELF section now
  174          * in all Linux ELF binaries, FreeBSD 4.1+, and some NetBSD ones.
  175          */
  176 
  177         /* If the executable has a brand, search for it in the brand list. */
  178         for (i = 0; i < MAX_BRANDS; i++) {
  179                 bi = elf_brand_list[i];
  180                 if (bi != NULL && hdr->e_machine == bi->machine &&
  181                     (hdr->e_ident[EI_OSABI] == bi->brand ||
  182                     strncmp((const char *)&hdr->e_ident[OLD_EI_BRAND],
  183                     bi->compat_3_brand, strlen(bi->compat_3_brand)) == 0))
  184                         return (bi);
  185         }
  186 
  187         /* Lacking a known brand, search for a recognized interpreter. */
  188         if (interp != NULL) {
  189                 for (i = 0; i < MAX_BRANDS; i++) {
  190                         bi = elf_brand_list[i];
  191                         if (bi != NULL && hdr->e_machine == bi->machine &&
  192                             strcmp(interp, bi->interp_path) == 0)
  193                                 return (bi);
  194                 }
  195         }
  196 
  197         /* Lacking a recognized interpreter, try the default brand */
  198         for (i = 0; i < MAX_BRANDS; i++) {
  199                 bi = elf_brand_list[i];
  200                 if (bi != NULL && hdr->e_machine == bi->machine &&
  201                     __elfN(fallback_brand) == bi->brand)
  202                         return (bi);
  203         }
  204         return (NULL);
  205 }
  206 
  207 static int
  208 __elfN(check_header)(const Elf_Ehdr *hdr)
  209 {
  210         Elf_Brandinfo *bi;
  211         int i;
  212 
  213         if (!IS_ELF(*hdr) ||
  214             hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS ||
  215             hdr->e_ident[EI_DATA] != ELF_TARG_DATA ||
  216             hdr->e_ident[EI_VERSION] != EV_CURRENT ||
  217             hdr->e_phentsize != sizeof(Elf_Phdr) ||
  218             hdr->e_version != ELF_TARG_VER)
  219                 return (ENOEXEC);
  220 
  221         /*
  222          * Make sure we have at least one brand for this machine.
  223          */
  224 
  225         for (i = 0; i < MAX_BRANDS; i++) {
  226                 bi = elf_brand_list[i];
  227                 if (bi != NULL && bi->machine == hdr->e_machine)
  228                         break;
  229         }
  230         if (i == MAX_BRANDS)
  231                 return (ENOEXEC);
  232 
  233         return (0);
  234 }
  235 
  236 static int
  237 __elfN(map_partial)(vm_map_t map, vm_object_t object, vm_ooffset_t offset,
  238     vm_offset_t start, vm_offset_t end, vm_prot_t prot)
  239 {
  240         struct sf_buf *sf;
  241         int error;
  242         vm_offset_t off;
  243 
  244         /*
  245          * Create the page if it doesn't exist yet. Ignore errors.
  246          */
  247         vm_map_lock(map);
  248         vm_map_insert(map, NULL, 0, trunc_page(start), round_page(end),
  249             VM_PROT_ALL, VM_PROT_ALL, 0);
  250         vm_map_unlock(map);
  251 
  252         /*
  253          * Find the page from the underlying object.
  254          */
  255         if (object) {
  256                 sf = vm_imgact_map_page(object, offset);
  257                 if (sf == NULL)
  258                         return (KERN_FAILURE);
  259                 off = offset - trunc_page(offset);
  260                 error = copyout((caddr_t)sf_buf_kva(sf) + off, (caddr_t)start,
  261                     end - start);
  262                 vm_imgact_unmap_page(sf);
  263                 if (error) {
  264                         return (KERN_FAILURE);
  265                 }
  266         }
  267 
  268         return (KERN_SUCCESS);
  269 }
  270 
  271 static int
  272 __elfN(map_insert)(vm_map_t map, vm_object_t object, vm_ooffset_t offset,
  273     vm_offset_t start, vm_offset_t end, vm_prot_t prot, int cow)
  274 {
  275         struct sf_buf *sf;
  276         vm_offset_t off;
  277         vm_size_t sz;
  278         int error, rv;
  279 
  280         if (start != trunc_page(start)) {
  281                 rv = __elfN(map_partial)(map, object, offset, start,
  282                     round_page(start), prot);
  283                 if (rv)
  284                         return (rv);
  285                 offset += round_page(start) - start;
  286                 start = round_page(start);
  287         }
  288         if (end != round_page(end)) {
  289                 rv = __elfN(map_partial)(map, object, offset +
  290                     trunc_page(end) - start, trunc_page(end), end, prot);
  291                 if (rv)
  292                         return (rv);
  293                 end = trunc_page(end);
  294         }
  295         if (end > start) {
  296                 if (offset & PAGE_MASK) {
  297                         /*
  298                          * The mapping is not page aligned. This means we have
  299                          * to copy the data. Sigh.
  300                          */
  301                         rv = vm_map_find(map, NULL, 0, &start, end - start,
  302                             FALSE, prot | VM_PROT_WRITE, VM_PROT_ALL, 0);
  303                         if (rv)
  304                                 return (rv);
  305                         if (object == NULL)
  306                                 return (KERN_SUCCESS);
  307                         for (; start < end; start += sz) {
  308                                 sf = vm_imgact_map_page(object, offset);
  309                                 if (sf == NULL)
  310                                         return (KERN_FAILURE);
  311                                 off = offset - trunc_page(offset);
  312                                 sz = end - start;
  313                                 if (sz > PAGE_SIZE - off)
  314                                         sz = PAGE_SIZE - off;
  315                                 error = copyout((caddr_t)sf_buf_kva(sf) + off,
  316                                     (caddr_t)start, sz);
  317                                 vm_imgact_unmap_page(sf);
  318                                 if (error) {
  319                                         return (KERN_FAILURE);
  320                                 }
  321                                 offset += sz;
  322                         }
  323                         rv = KERN_SUCCESS;
  324                 } else {
  325                         vm_object_reference(object);
  326                         vm_map_lock(map);
  327                         rv = vm_map_insert(map, object, offset, start, end,
  328                             prot, VM_PROT_ALL, cow);
  329                         vm_map_unlock(map);
  330                         if (rv != KERN_SUCCESS)
  331                                 vm_object_deallocate(object);
  332                 }
  333                 return (rv);
  334         } else {
  335                 return (KERN_SUCCESS);
  336         }
  337 }
  338 
  339 static int
  340 __elfN(load_section)(struct vmspace *vmspace,
  341         vm_object_t object, vm_offset_t offset,
  342         caddr_t vmaddr, size_t memsz, size_t filsz, vm_prot_t prot,
  343         size_t pagesize)
  344 {
  345         struct sf_buf *sf;
  346         size_t map_len;
  347         vm_offset_t map_addr;
  348         int error, rv, cow;
  349         size_t copy_len;
  350         vm_offset_t file_addr;
  351 
  352         /*
  353          * It's necessary to fail if the filsz + offset taken from the
  354          * header is greater than the actual file pager object's size.
  355          * If we were to allow this, then the vm_map_find() below would
  356          * walk right off the end of the file object and into the ether.
  357          *
  358          * While I'm here, might as well check for something else that
  359          * is invalid: filsz cannot be greater than memsz.
  360          */
  361         if ((off_t)filsz + offset > object->un_pager.vnp.vnp_size ||
  362             filsz > memsz) {
  363                 uprintf("elf_load_section: truncated ELF file\n");
  364                 return (ENOEXEC);
  365         }
  366 
  367         map_addr = trunc_page_ps((vm_offset_t)vmaddr, pagesize);
  368         file_addr = trunc_page_ps(offset, pagesize);
  369 
  370         /*
  371          * We have two choices.  We can either clear the data in the last page
  372          * of an oversized mapping, or we can start the anon mapping a page
  373          * early and copy the initialized data into that first page.  We
  374          * choose the second..
  375          */
  376         if (memsz > filsz)
  377                 map_len = trunc_page_ps(offset + filsz, pagesize) - file_addr;
  378         else
  379                 map_len = round_page_ps(offset + filsz, pagesize) - file_addr;
  380 
  381         if (map_len != 0) {
  382                 /* cow flags: don't dump readonly sections in core */
  383                 cow = MAP_COPY_ON_WRITE | MAP_PREFAULT |
  384                     (prot & VM_PROT_WRITE ? 0 : MAP_DISABLE_COREDUMP);
  385 
  386                 rv = __elfN(map_insert)(&vmspace->vm_map,
  387                                       object,
  388                                       file_addr,        /* file offset */
  389                                       map_addr,         /* virtual start */
  390                                       map_addr + map_len,/* virtual end */
  391                                       prot,
  392                                       cow);
  393                 if (rv != KERN_SUCCESS)
  394                         return (EINVAL);
  395 
  396                 /* we can stop now if we've covered it all */
  397                 if (memsz == filsz) {
  398                         return (0);
  399                 }
  400         }
  401 
  402 
  403         /*
  404          * We have to get the remaining bit of the file into the first part
  405          * of the oversized map segment.  This is normally because the .data
  406          * segment in the file is extended to provide bss.  It's a neat idea
  407          * to try and save a page, but it's a pain in the behind to implement.
  408          */
  409         copy_len = (offset + filsz) - trunc_page_ps(offset + filsz, pagesize);
  410         map_addr = trunc_page_ps((vm_offset_t)vmaddr + filsz, pagesize);
  411         map_len = round_page_ps((vm_offset_t)vmaddr + memsz, pagesize) -
  412             map_addr;
  413 
  414         /* This had damn well better be true! */
  415         if (map_len != 0) {
  416                 rv = __elfN(map_insert)(&vmspace->vm_map, NULL, 0, map_addr,
  417                     map_addr + map_len, VM_PROT_ALL, 0);
  418                 if (rv != KERN_SUCCESS) {
  419                         return (EINVAL);
  420                 }
  421         }
  422 
  423         if (copy_len != 0) {
  424                 vm_offset_t off;
  425 
  426                 sf = vm_imgact_map_page(object, offset + filsz);
  427                 if (sf == NULL)
  428                         return (EIO);
  429 
  430                 /* send the page fragment to user space */
  431                 off = trunc_page_ps(offset + filsz, pagesize) -
  432                     trunc_page(offset + filsz);
  433                 error = copyout((caddr_t)sf_buf_kva(sf) + off,
  434                     (caddr_t)map_addr, copy_len);
  435                 vm_imgact_unmap_page(sf);
  436                 if (error) {
  437                         return (error);
  438                 }
  439         }
  440 
  441         /*
  442          * set it to the specified protection.
  443          * XXX had better undo the damage from pasting over the cracks here!
  444          */
  445         vm_map_protect(&vmspace->vm_map, trunc_page(map_addr),
  446             round_page(map_addr + map_len),  prot, FALSE);
  447 
  448         return (0);
  449 }
  450 
  451 /*
  452  * Load the file "file" into memory.  It may be either a shared object
  453  * or an executable.
  454  *
  455  * The "addr" reference parameter is in/out.  On entry, it specifies
  456  * the address where a shared object should be loaded.  If the file is
  457  * an executable, this value is ignored.  On exit, "addr" specifies
  458  * where the file was actually loaded.
  459  *
  460  * The "entry" reference parameter is out only.  On exit, it specifies
  461  * the entry point for the loaded file.
  462  */
  463 static int
  464 __elfN(load_file)(struct proc *p, const char *file, u_long *addr,
  465         u_long *entry, size_t pagesize)
  466 {
  467         struct {
  468                 struct nameidata nd;
  469                 struct vattr attr;
  470                 struct image_params image_params;
  471         } *tempdata;
  472         const Elf_Ehdr *hdr = NULL;
  473         const Elf_Phdr *phdr = NULL;
  474         struct nameidata *nd;
  475         struct vmspace *vmspace = p->p_vmspace;
  476         struct vattr *attr;
  477         struct image_params *imgp;
  478         vm_prot_t prot;
  479         u_long rbase;
  480         u_long base_addr = 0;
  481         int vfslocked, error, i, numsegs;
  482 
  483         if (curthread->td_proc != p)
  484                 panic("elf_load_file - thread");        /* XXXKSE DIAGNOSTIC */
  485 
  486         tempdata = malloc(sizeof(*tempdata), M_TEMP, M_WAITOK);
  487         nd = &tempdata->nd;
  488         attr = &tempdata->attr;
  489         imgp = &tempdata->image_params;
  490 
  491         /*
  492          * Initialize part of the common data
  493          */
  494         imgp->proc = p;
  495         imgp->attr = attr;
  496         imgp->firstpage = NULL;
  497         imgp->image_header = NULL;
  498         imgp->object = NULL;
  499         imgp->execlabel = NULL;
  500 
  501         /* XXXKSE */
  502         NDINIT(nd, LOOKUP, MPSAFE|LOCKLEAF|FOLLOW, UIO_SYSSPACE, file,
  503             curthread);
  504         vfslocked = 0;
  505         if ((error = namei(nd)) != 0) {
  506                 nd->ni_vp = NULL;
  507                 goto fail;
  508         }
  509         vfslocked = NDHASGIANT(nd);
  510         NDFREE(nd, NDF_ONLY_PNBUF);
  511         imgp->vp = nd->ni_vp;
  512 
  513         /*
  514          * Check permissions, modes, uid, etc on the file, and "open" it.
  515          */
  516         error = exec_check_permissions(imgp);
  517         if (error)
  518                 goto fail;
  519 
  520         error = exec_map_first_page(imgp);
  521         if (error)
  522                 goto fail;
  523 
  524         /*
  525          * Also make certain that the interpreter stays the same, so set
  526          * its VV_TEXT flag, too.
  527          */
  528         nd->ni_vp->v_vflag |= VV_TEXT;
  529 
  530         imgp->object = nd->ni_vp->v_object;
  531 
  532         hdr = (const Elf_Ehdr *)imgp->image_header;
  533         if ((error = __elfN(check_header)(hdr)) != 0)
  534                 goto fail;
  535         if (hdr->e_type == ET_DYN)
  536                 rbase = *addr;
  537         else if (hdr->e_type == ET_EXEC)
  538                 rbase = 0;
  539         else {
  540                 error = ENOEXEC;
  541                 goto fail;
  542         }
  543 
  544         /* Only support headers that fit within first page for now      */
  545         /*    (multiplication of two Elf_Half fields will not overflow) */
  546         if ((hdr->e_phoff > PAGE_SIZE) ||
  547             (hdr->e_phentsize * hdr->e_phnum) > PAGE_SIZE - hdr->e_phoff) {
  548                 error = ENOEXEC;
  549                 goto fail;
  550         }
  551 
  552         phdr = (const Elf_Phdr *)(imgp->image_header + hdr->e_phoff);
  553         if (!aligned(phdr, Elf_Addr)) {
  554                 error = ENOEXEC;
  555                 goto fail;
  556         }
  557 
  558         for (i = 0, numsegs = 0; i < hdr->e_phnum; i++) {
  559                 if (phdr[i].p_type == PT_LOAD) {        /* Loadable segment */
  560                         prot = 0;
  561                         if (phdr[i].p_flags & PF_X)
  562                                 prot |= VM_PROT_EXECUTE;
  563                         if (phdr[i].p_flags & PF_W)
  564                                 prot |= VM_PROT_WRITE;
  565                         if (phdr[i].p_flags & PF_R)
  566                                 prot |= VM_PROT_READ;
  567 
  568                         if ((error = __elfN(load_section)(vmspace,
  569                             imgp->object, phdr[i].p_offset,
  570                             (caddr_t)(uintptr_t)phdr[i].p_vaddr + rbase,
  571                             phdr[i].p_memsz, phdr[i].p_filesz, prot,
  572                             pagesize)) != 0)
  573                                 goto fail;
  574                         /*
  575                          * Establish the base address if this is the
  576                          * first segment.
  577                          */
  578                         if (numsegs == 0)
  579                                 base_addr = trunc_page(phdr[i].p_vaddr +
  580                                     rbase);
  581                         numsegs++;
  582                 }
  583         }
  584         *addr = base_addr;
  585         *entry = (unsigned long)hdr->e_entry + rbase;
  586 
  587 fail:
  588         if (imgp->firstpage)
  589                 exec_unmap_first_page(imgp);
  590 
  591         if (nd->ni_vp)
  592                 vput(nd->ni_vp);
  593 
  594         VFS_UNLOCK_GIANT(vfslocked);
  595         free(tempdata, M_TEMP);
  596 
  597         return (error);
  598 }
  599 
  600 static int
  601 __CONCAT(exec_, __elfN(imgact))(struct image_params *imgp)
  602 {
  603         const Elf_Ehdr *hdr = (const Elf_Ehdr *)imgp->image_header;
  604         const Elf_Phdr *phdr;
  605         Elf_Auxargs *elf_auxargs;
  606         struct vmspace *vmspace;
  607         vm_prot_t prot;
  608         u_long text_size = 0, data_size = 0, total_size = 0;
  609         u_long text_addr = 0, data_addr = 0;
  610         u_long seg_size, seg_addr;
  611         u_long addr, entry = 0, proghdr = 0;
  612         int error = 0, i;
  613         const char *interp = NULL;
  614         Elf_Brandinfo *brand_info;
  615         char *path;
  616         struct thread *td = curthread;
  617         struct sysentvec *sv;
  618 
  619         /*
  620          * Do we have a valid ELF header ?
  621          *
  622          * Only allow ET_EXEC & ET_DYN here, reject ET_DYN later
  623          * if particular brand doesn't support it.
  624          */
  625         if (__elfN(check_header)(hdr) != 0 ||
  626             (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN))
  627                 return (-1);
  628 
  629         /*
  630          * From here on down, we return an errno, not -1, as we've
  631          * detected an ELF file.
  632          */
  633 
  634         if ((hdr->e_phoff > PAGE_SIZE) ||
  635             (hdr->e_phoff + hdr->e_phentsize * hdr->e_phnum) > PAGE_SIZE) {
  636                 /* Only support headers in first page for now */
  637                 return (ENOEXEC);
  638         }
  639         phdr = (const Elf_Phdr *)(imgp->image_header + hdr->e_phoff);
  640         if (!aligned(phdr, Elf_Addr))
  641                 return (ENOEXEC);
  642         for (i = 0; i < hdr->e_phnum; i++) {
  643                 if (phdr[i].p_type == PT_INTERP) {
  644                         /* Path to interpreter */
  645                         if (phdr[i].p_filesz > MAXPATHLEN ||
  646                             phdr[i].p_offset + phdr[i].p_filesz > PAGE_SIZE)
  647                                 return (ENOEXEC);
  648                         interp = imgp->image_header + phdr[i].p_offset;
  649                         break;
  650                 }
  651         }
  652 
  653         brand_info = __elfN(get_brandinfo)(hdr, interp);
  654         if (brand_info == NULL) {
  655                 uprintf("ELF binary type \"%u\" not known.\n",
  656                     hdr->e_ident[EI_OSABI]);
  657                 return (ENOEXEC);
  658         }
  659         if (hdr->e_type == ET_DYN && brand_info->brand != ELFOSABI_LINUX)
  660                 return (ENOEXEC);
  661         sv = brand_info->sysvec;
  662         if (interp != NULL && brand_info->interp_newpath != NULL)
  663                 interp = brand_info->interp_newpath;
  664 
  665         /*
  666          * Avoid a possible deadlock if the current address space is destroyed
  667          * and that address space maps the locked vnode.  In the common case,
  668          * the locked vnode's v_usecount is decremented but remains greater
  669          * than zero.  Consequently, the vnode lock is not needed by vrele().
  670          * However, in cases where the vnode lock is external, such as nullfs,
  671          * v_usecount may become zero.
  672          */
  673         VOP_UNLOCK(imgp->vp, 0, td);
  674 
  675         exec_new_vmspace(imgp, sv);
  676         imgp->proc->p_sysent = sv;
  677 
  678         vn_lock(imgp->vp, LK_EXCLUSIVE | LK_RETRY, td);
  679 
  680         vmspace = imgp->proc->p_vmspace;
  681 
  682         for (i = 0; i < hdr->e_phnum; i++) {
  683                 switch (phdr[i].p_type) {
  684                 case PT_LOAD:   /* Loadable segment */
  685                         prot = 0;
  686                         if (phdr[i].p_flags & PF_X)
  687                                 prot |= VM_PROT_EXECUTE;
  688                         if (phdr[i].p_flags & PF_W)
  689                                 prot |= VM_PROT_WRITE;
  690                         if (phdr[i].p_flags & PF_R)
  691                                 prot |= VM_PROT_READ;
  692 
  693 #if defined(__ia64__) && __ELF_WORD_SIZE == 32 && defined(IA32_ME_HARDER)
  694                         /*
  695                          * Some x86 binaries assume read == executable,
  696                          * notably the M3 runtime and therefore cvsup
  697                          */
  698                         if (prot & VM_PROT_READ)
  699                                 prot |= VM_PROT_EXECUTE;
  700 #endif
  701 
  702                         if ((error = __elfN(load_section)(vmspace,
  703                             imgp->object, phdr[i].p_offset,
  704                             (caddr_t)(uintptr_t)phdr[i].p_vaddr,
  705                             phdr[i].p_memsz, phdr[i].p_filesz, prot,
  706                             sv->sv_pagesize)) != 0)
  707                                 return (error);
  708 
  709                         /*
  710                          * If this segment contains the program headers,
  711                          * remember their virtual address for the AT_PHDR
  712                          * aux entry. Static binaries don't usually include
  713                          * a PT_PHDR entry.
  714                          */
  715                         if (phdr[i].p_offset == 0 &&
  716                             hdr->e_phoff + hdr->e_phnum * hdr->e_phentsize
  717                                 <= phdr[i].p_filesz)
  718                                 proghdr = phdr[i].p_vaddr + hdr->e_phoff;
  719 
  720                         seg_addr = trunc_page(phdr[i].p_vaddr);
  721                         seg_size = round_page(phdr[i].p_memsz +
  722                             phdr[i].p_vaddr - seg_addr);
  723 
  724                         /*
  725                          * Is this .text or .data?  We can't use
  726                          * VM_PROT_WRITE or VM_PROT_EXEC, it breaks the
  727                          * alpha terribly and possibly does other bad
  728                          * things so we stick to the old way of figuring
  729                          * it out:  If the segment contains the program
  730                          * entry point, it's a text segment, otherwise it
  731                          * is a data segment.
  732                          *
  733                          * Note that obreak() assumes that data_addr + 
  734                          * data_size == end of data load area, and the ELF
  735                          * file format expects segments to be sorted by
  736                          * address.  If multiple data segments exist, the
  737                          * last one will be used.
  738                          */
  739                         if (hdr->e_entry >= phdr[i].p_vaddr &&
  740                             hdr->e_entry < (phdr[i].p_vaddr +
  741                             phdr[i].p_memsz)) {
  742                                 text_size = seg_size;
  743                                 text_addr = seg_addr;
  744                                 entry = (u_long)hdr->e_entry;
  745                         } else {
  746                                 data_size = seg_size;
  747                                 data_addr = seg_addr;
  748                         }
  749                         total_size += seg_size;
  750                         break;
  751                 case PT_PHDR:   /* Program header table info */
  752                         proghdr = phdr[i].p_vaddr;
  753                         break;
  754                 default:
  755                         break;
  756                 }
  757         }
  758         
  759         if (data_addr == 0 && data_size == 0) {
  760                 data_addr = text_addr;
  761                 data_size = text_size;
  762         }
  763 
  764         /*
  765          * Check limits.  It should be safe to check the
  766          * limits after loading the segments since we do
  767          * not actually fault in all the segments pages.
  768          */
  769         PROC_LOCK(imgp->proc);
  770         if (data_size > lim_cur(imgp->proc, RLIMIT_DATA) ||
  771             text_size > maxtsiz ||
  772             total_size > lim_cur(imgp->proc, RLIMIT_VMEM)) {
  773                 PROC_UNLOCK(imgp->proc);
  774                 return (ENOMEM);
  775         }
  776 
  777         vmspace->vm_tsize = text_size >> PAGE_SHIFT;
  778         vmspace->vm_taddr = (caddr_t)(uintptr_t)text_addr;
  779         vmspace->vm_dsize = data_size >> PAGE_SHIFT;
  780         vmspace->vm_daddr = (caddr_t)(uintptr_t)data_addr;
  781 
  782         /*
  783          * We load the dynamic linker where a userland call
  784          * to mmap(0, ...) would put it.  The rationale behind this
  785          * calculation is that it leaves room for the heap to grow to
  786          * its maximum allowed size.
  787          */
  788         addr = round_page((vm_offset_t)imgp->proc->p_vmspace->vm_daddr +
  789             lim_max(imgp->proc, RLIMIT_DATA));
  790         PROC_UNLOCK(imgp->proc);
  791 
  792         imgp->entry_addr = entry;
  793 
  794         if (interp != NULL) {
  795                 VOP_UNLOCK(imgp->vp, 0, td);
  796                 if (brand_info->emul_path != NULL &&
  797                     brand_info->emul_path[0] != '\0') {
  798                         path = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
  799                         snprintf(path, MAXPATHLEN, "%s%s",
  800                             brand_info->emul_path, interp);
  801                         error = __elfN(load_file)(imgp->proc, path, &addr,
  802                             &imgp->entry_addr, sv->sv_pagesize);
  803                         free(path, M_TEMP);
  804                         if (error == 0)
  805                                 interp = NULL;
  806                 }
  807                 if (interp != NULL) {
  808                         error = __elfN(load_file)(imgp->proc, interp, &addr,
  809                             &imgp->entry_addr, sv->sv_pagesize);
  810                 }
  811                 vn_lock(imgp->vp, LK_EXCLUSIVE | LK_RETRY, td);
  812                 if (error != 0) {
  813                         uprintf("ELF interpreter %s not found\n", interp);
  814                         return (error);
  815                 }
  816         }
  817 
  818         /*
  819          * Construct auxargs table (used by the fixup routine)
  820          */
  821         elf_auxargs = malloc(sizeof(Elf_Auxargs), M_TEMP, M_WAITOK);
  822         elf_auxargs->execfd = -1;
  823         elf_auxargs->phdr = proghdr;
  824         elf_auxargs->phent = hdr->e_phentsize;
  825         elf_auxargs->phnum = hdr->e_phnum;
  826         elf_auxargs->pagesz = PAGE_SIZE;
  827         elf_auxargs->base = addr;
  828         elf_auxargs->flags = 0;
  829         elf_auxargs->entry = entry;
  830         elf_auxargs->trace = elf_trace;
  831 
  832         imgp->auxargs = elf_auxargs;
  833         imgp->interpreted = 0;
  834 
  835         return (error);
  836 }
  837 
  838 #define suword __CONCAT(suword, __ELF_WORD_SIZE)
  839 
  840 int
  841 __elfN(freebsd_fixup)(register_t **stack_base, struct image_params *imgp)
  842 {
  843         Elf_Auxargs *args = (Elf_Auxargs *)imgp->auxargs;
  844         Elf_Addr *base;
  845         Elf_Addr *pos;
  846 
  847         base = (Elf_Addr *)*stack_base;
  848         pos = base + (imgp->args->argc + imgp->args->envc + 2);
  849 
  850         if (args->trace) {
  851                 AUXARGS_ENTRY(pos, AT_DEBUG, 1);
  852         }
  853         if (args->execfd != -1) {
  854                 AUXARGS_ENTRY(pos, AT_EXECFD, args->execfd);
  855         }
  856         AUXARGS_ENTRY(pos, AT_PHDR, args->phdr);
  857         AUXARGS_ENTRY(pos, AT_PHENT, args->phent);
  858         AUXARGS_ENTRY(pos, AT_PHNUM, args->phnum);
  859         AUXARGS_ENTRY(pos, AT_PAGESZ, args->pagesz);
  860         AUXARGS_ENTRY(pos, AT_FLAGS, args->flags);
  861         AUXARGS_ENTRY(pos, AT_ENTRY, args->entry);
  862         AUXARGS_ENTRY(pos, AT_BASE, args->base);
  863         AUXARGS_ENTRY(pos, AT_NULL, 0);
  864 
  865         free(imgp->auxargs, M_TEMP);
  866         imgp->auxargs = NULL;
  867 
  868         base--;
  869         suword(base, (long)imgp->args->argc);
  870         *stack_base = (register_t *)base;
  871         return (0);
  872 }
  873 
  874 /*
  875  * Code for generating ELF core dumps.
  876  */
  877 
  878 typedef void (*segment_callback)(vm_map_entry_t, void *);
  879 
  880 /* Closure for cb_put_phdr(). */
  881 struct phdr_closure {
  882         Elf_Phdr *phdr;         /* Program header to fill in */
  883         Elf_Off offset;         /* Offset of segment in core file */
  884 };
  885 
  886 /* Closure for cb_size_segment(). */
  887 struct sseg_closure {
  888         int count;              /* Count of writable segments. */
  889         size_t size;            /* Total size of all writable segments. */
  890 };
  891 
  892 static void cb_put_phdr(vm_map_entry_t, void *);
  893 static void cb_size_segment(vm_map_entry_t, void *);
  894 static void each_writable_segment(struct thread *, segment_callback, void *);
  895 static int __elfN(corehdr)(struct thread *, struct vnode *, struct ucred *,
  896     int, void *, size_t);
  897 static void __elfN(puthdr)(struct thread *, void *, size_t *, int);
  898 static void __elfN(putnote)(void *, size_t *, const char *, int,
  899     const void *, size_t);
  900 
  901 extern int osreldate;
  902 
  903 int
  904 __elfN(coredump)(td, vp, limit)
  905         struct thread *td;
  906         struct vnode *vp;
  907         off_t limit;
  908 {
  909         struct ucred *cred = td->td_ucred;
  910         int error = 0;
  911         struct sseg_closure seginfo;
  912         void *hdr;
  913         size_t hdrsize;
  914 
  915         /* Size the program segments. */
  916         seginfo.count = 0;
  917         seginfo.size = 0;
  918         each_writable_segment(td, cb_size_segment, &seginfo);
  919 
  920         /*
  921          * Calculate the size of the core file header area by making
  922          * a dry run of generating it.  Nothing is written, but the
  923          * size is calculated.
  924          */
  925         hdrsize = 0;
  926         __elfN(puthdr)(td, (void *)NULL, &hdrsize, seginfo.count);
  927 
  928         if (hdrsize + seginfo.size >= limit)
  929                 return (EFAULT);
  930 
  931         /*
  932          * Allocate memory for building the header, fill it up,
  933          * and write it out.
  934          */
  935         hdr = malloc(hdrsize, M_TEMP, M_WAITOK);
  936         if (hdr == NULL) {
  937                 return (EINVAL);
  938         }
  939         error = __elfN(corehdr)(td, vp, cred, seginfo.count, hdr, hdrsize);
  940 
  941         /* Write the contents of all of the writable segments. */
  942         if (error == 0) {
  943                 Elf_Phdr *php;
  944                 off_t offset;
  945                 int i;
  946 
  947                 php = (Elf_Phdr *)((char *)hdr + sizeof(Elf_Ehdr)) + 1;
  948                 offset = hdrsize;
  949                 for (i = 0; i < seginfo.count; i++) {
  950                         error = vn_rdwr_inchunks(UIO_WRITE, vp,
  951                             (caddr_t)(uintptr_t)php->p_vaddr,
  952                             php->p_filesz, offset, UIO_USERSPACE,
  953                             IO_UNIT | IO_DIRECT, cred, NOCRED, NULL,
  954                             curthread); /* XXXKSE */
  955                         if (error != 0)
  956                                 break;
  957                         offset += php->p_filesz;
  958                         php++;
  959                 }
  960         }
  961         free(hdr, M_TEMP);
  962 
  963         return (error);
  964 }
  965 
  966 /*
  967  * A callback for each_writable_segment() to write out the segment's
  968  * program header entry.
  969  */
  970 static void
  971 cb_put_phdr(entry, closure)
  972         vm_map_entry_t entry;
  973         void *closure;
  974 {
  975         struct phdr_closure *phc = (struct phdr_closure *)closure;
  976         Elf_Phdr *phdr = phc->phdr;
  977 
  978         phc->offset = round_page(phc->offset);
  979 
  980         phdr->p_type = PT_LOAD;
  981         phdr->p_offset = phc->offset;
  982         phdr->p_vaddr = entry->start;
  983         phdr->p_paddr = 0;
  984         phdr->p_filesz = phdr->p_memsz = entry->end - entry->start;
  985         phdr->p_align = PAGE_SIZE;
  986         phdr->p_flags = 0;
  987         if (entry->protection & VM_PROT_READ)
  988                 phdr->p_flags |= PF_R;
  989         if (entry->protection & VM_PROT_WRITE)
  990                 phdr->p_flags |= PF_W;
  991         if (entry->protection & VM_PROT_EXECUTE)
  992                 phdr->p_flags |= PF_X;
  993 
  994         phc->offset += phdr->p_filesz;
  995         phc->phdr++;
  996 }
  997 
  998 /*
  999  * A callback for each_writable_segment() to gather information about
 1000  * the number of segments and their total size.
 1001  */
 1002 static void
 1003 cb_size_segment(entry, closure)
 1004         vm_map_entry_t entry;
 1005         void *closure;
 1006 {
 1007         struct sseg_closure *ssc = (struct sseg_closure *)closure;
 1008 
 1009         ssc->count++;
 1010         ssc->size += entry->end - entry->start;
 1011 }
 1012 
 1013 /*
 1014  * For each writable segment in the process's memory map, call the given
 1015  * function with a pointer to the map entry and some arbitrary
 1016  * caller-supplied data.
 1017  */
 1018 static void
 1019 each_writable_segment(td, func, closure)
 1020         struct thread *td;
 1021         segment_callback func;
 1022         void *closure;
 1023 {
 1024         struct proc *p = td->td_proc;
 1025         vm_map_t map = &p->p_vmspace->vm_map;
 1026         vm_map_entry_t entry;
 1027         vm_object_t backing_object, object;
 1028         boolean_t ignore_entry;
 1029 
 1030         vm_map_lock_read(map);
 1031         for (entry = map->header.next; entry != &map->header;
 1032             entry = entry->next) {
 1033                 /*
 1034                  * Don't dump inaccessible mappings, deal with legacy
 1035                  * coredump mode.
 1036                  *
 1037                  * Note that read-only segments related to the elf binary
 1038                  * are marked MAP_ENTRY_NOCOREDUMP now so we no longer
 1039                  * need to arbitrarily ignore such segments.
 1040                  */
 1041                 if (elf_legacy_coredump) {
 1042                         if ((entry->protection & VM_PROT_RW) != VM_PROT_RW)
 1043                                 continue;
 1044                 } else {
 1045                         if ((entry->protection & VM_PROT_ALL) == 0)
 1046                                 continue;
 1047                 }
 1048 
 1049                 /*
 1050                  * Dont include memory segment in the coredump if
 1051                  * MAP_NOCORE is set in mmap(2) or MADV_NOCORE in
 1052                  * madvise(2).  Do not dump submaps (i.e. parts of the
 1053                  * kernel map).
 1054                  */
 1055                 if (entry->eflags & (MAP_ENTRY_NOCOREDUMP|MAP_ENTRY_IS_SUB_MAP))
 1056                         continue;
 1057 
 1058                 if ((object = entry->object.vm_object) == NULL)
 1059                         continue;
 1060 
 1061                 /* Ignore memory-mapped devices and such things. */
 1062                 VM_OBJECT_LOCK(object);
 1063                 while ((backing_object = object->backing_object) != NULL) {
 1064                         VM_OBJECT_LOCK(backing_object);
 1065                         VM_OBJECT_UNLOCK(object);
 1066                         object = backing_object;
 1067                 }
 1068                 ignore_entry = object->type != OBJT_DEFAULT &&
 1069                     object->type != OBJT_SWAP && object->type != OBJT_VNODE;
 1070                 VM_OBJECT_UNLOCK(object);
 1071                 if (ignore_entry)
 1072                         continue;
 1073 
 1074                 (*func)(entry, closure);
 1075         }
 1076         vm_map_unlock_read(map);
 1077 }
 1078 
 1079 /*
 1080  * Write the core file header to the file, including padding up to
 1081  * the page boundary.
 1082  */
 1083 static int
 1084 __elfN(corehdr)(td, vp, cred, numsegs, hdr, hdrsize)
 1085         struct thread *td;
 1086         struct vnode *vp;
 1087         struct ucred *cred;
 1088         int numsegs;
 1089         size_t hdrsize;
 1090         void *hdr;
 1091 {
 1092         size_t off;
 1093 
 1094         /* Fill in the header. */
 1095         bzero(hdr, hdrsize);
 1096         off = 0;
 1097         __elfN(puthdr)(td, hdr, &off, numsegs);
 1098 
 1099         /* Write it to the core file. */
 1100         return (vn_rdwr_inchunks(UIO_WRITE, vp, hdr, hdrsize, (off_t)0,
 1101             UIO_SYSSPACE, IO_UNIT | IO_DIRECT, cred, NOCRED, NULL,
 1102             td)); /* XXXKSE */
 1103 }
 1104 
 1105 #if defined(COMPAT_IA32) && __ELF_WORD_SIZE == 32
 1106 typedef struct prstatus32 elf_prstatus_t;
 1107 typedef struct prpsinfo32 elf_prpsinfo_t;
 1108 typedef struct fpreg32 elf_prfpregset_t;
 1109 typedef struct fpreg32 elf_fpregset_t;
 1110 typedef struct reg32 elf_gregset_t;
 1111 #else
 1112 typedef prstatus_t elf_prstatus_t;
 1113 typedef prpsinfo_t elf_prpsinfo_t;
 1114 typedef prfpregset_t elf_prfpregset_t;
 1115 typedef prfpregset_t elf_fpregset_t;
 1116 typedef gregset_t elf_gregset_t;
 1117 #endif
 1118 
 1119 static void
 1120 __elfN(puthdr)(struct thread *td, void *dst, size_t *off, int numsegs)
 1121 {
 1122         struct {
 1123                 elf_prstatus_t status;
 1124                 elf_prfpregset_t fpregset;
 1125                 elf_prpsinfo_t psinfo;
 1126         } *tempdata;
 1127         elf_prstatus_t *status;
 1128         elf_prfpregset_t *fpregset;
 1129         elf_prpsinfo_t *psinfo;
 1130         struct proc *p;
 1131         struct thread *thr;
 1132         size_t ehoff, noteoff, notesz, phoff;
 1133 
 1134         p = td->td_proc;
 1135 
 1136         ehoff = *off;
 1137         *off += sizeof(Elf_Ehdr);
 1138 
 1139         phoff = *off;
 1140         *off += (numsegs + 1) * sizeof(Elf_Phdr);
 1141 
 1142         noteoff = *off;
 1143         /*
 1144          * Don't allocate space for the notes if we're just calculating
 1145          * the size of the header. We also don't collect the data.
 1146          */
 1147         if (dst != NULL) {
 1148                 tempdata = malloc(sizeof(*tempdata), M_TEMP, M_ZERO|M_WAITOK);
 1149                 status = &tempdata->status;
 1150                 fpregset = &tempdata->fpregset;
 1151                 psinfo = &tempdata->psinfo;
 1152         } else {
 1153                 tempdata = NULL;
 1154                 status = NULL;
 1155                 fpregset = NULL;
 1156                 psinfo = NULL;
 1157         }
 1158 
 1159         if (dst != NULL) {
 1160                 psinfo->pr_version = PRPSINFO_VERSION;
 1161                 psinfo->pr_psinfosz = sizeof(elf_prpsinfo_t);
 1162                 strlcpy(psinfo->pr_fname, p->p_comm, sizeof(psinfo->pr_fname));
 1163                 /*
 1164                  * XXX - We don't fill in the command line arguments properly
 1165                  * yet.
 1166                  */
 1167                 strlcpy(psinfo->pr_psargs, p->p_comm,
 1168                     sizeof(psinfo->pr_psargs));
 1169         }
 1170         __elfN(putnote)(dst, off, "FreeBSD", NT_PRPSINFO, psinfo,
 1171             sizeof *psinfo);
 1172 
 1173         /*
 1174          * To have the debugger select the right thread (LWP) as the initial
 1175          * thread, we dump the state of the thread passed to us in td first.
 1176          * This is the thread that causes the core dump and thus likely to
 1177          * be the right thread one wants to have selected in the debugger.
 1178          */
 1179         thr = td;
 1180         while (thr != NULL) {
 1181                 if (dst != NULL) {
 1182                         status->pr_version = PRSTATUS_VERSION;
 1183                         status->pr_statussz = sizeof(elf_prstatus_t);
 1184                         status->pr_gregsetsz = sizeof(elf_gregset_t);
 1185                         status->pr_fpregsetsz = sizeof(elf_fpregset_t);
 1186                         status->pr_osreldate = osreldate;
 1187                         status->pr_cursig = p->p_sig;
 1188                         status->pr_pid = thr->td_tid;
 1189 #if defined(COMPAT_IA32) && __ELF_WORD_SIZE == 32
 1190                         fill_regs32(thr, &status->pr_reg);
 1191                         fill_fpregs32(thr, fpregset);
 1192 #else
 1193                         fill_regs(thr, &status->pr_reg);
 1194                         fill_fpregs(thr, fpregset);
 1195 #endif
 1196                 }
 1197                 __elfN(putnote)(dst, off, "FreeBSD", NT_PRSTATUS, status,
 1198                     sizeof *status);
 1199                 __elfN(putnote)(dst, off, "FreeBSD", NT_FPREGSET, fpregset,
 1200                     sizeof *fpregset);
 1201                 /*
 1202                  * Allow for MD specific notes, as well as any MD
 1203                  * specific preparations for writing MI notes.
 1204                  */
 1205                 __elfN(dump_thread)(thr, dst, off);
 1206 
 1207                 thr = (thr == td) ? TAILQ_FIRST(&p->p_threads) :
 1208                     TAILQ_NEXT(thr, td_plist);
 1209                 if (thr == td)
 1210                         thr = TAILQ_NEXT(thr, td_plist);
 1211         }
 1212 
 1213         notesz = *off - noteoff;
 1214 
 1215         if (dst != NULL)
 1216                 free(tempdata, M_TEMP);
 1217 
 1218         /* Align up to a page boundary for the program segments. */
 1219         *off = round_page(*off);
 1220 
 1221         if (dst != NULL) {
 1222                 Elf_Ehdr *ehdr;
 1223                 Elf_Phdr *phdr;
 1224                 struct phdr_closure phc;
 1225 
 1226                 /*
 1227                  * Fill in the ELF header.
 1228                  */
 1229                 ehdr = (Elf_Ehdr *)((char *)dst + ehoff);
 1230                 ehdr->e_ident[EI_MAG0] = ELFMAG0;
 1231                 ehdr->e_ident[EI_MAG1] = ELFMAG1;
 1232                 ehdr->e_ident[EI_MAG2] = ELFMAG2;
 1233                 ehdr->e_ident[EI_MAG3] = ELFMAG3;
 1234                 ehdr->e_ident[EI_CLASS] = ELF_CLASS;
 1235                 ehdr->e_ident[EI_DATA] = ELF_DATA;
 1236                 ehdr->e_ident[EI_VERSION] = EV_CURRENT;
 1237                 ehdr->e_ident[EI_OSABI] = ELFOSABI_FREEBSD;
 1238                 ehdr->e_ident[EI_ABIVERSION] = 0;
 1239                 ehdr->e_ident[EI_PAD] = 0;
 1240                 ehdr->e_type = ET_CORE;
 1241 #if defined(COMPAT_IA32) && __ELF_WORD_SIZE == 32
 1242                 ehdr->e_machine = EM_386;
 1243 #else
 1244                 ehdr->e_machine = ELF_ARCH;
 1245 #endif
 1246                 ehdr->e_version = EV_CURRENT;
 1247                 ehdr->e_entry = 0;
 1248                 ehdr->e_phoff = phoff;
 1249                 ehdr->e_flags = 0;
 1250                 ehdr->e_ehsize = sizeof(Elf_Ehdr);
 1251                 ehdr->e_phentsize = sizeof(Elf_Phdr);
 1252                 ehdr->e_phnum = numsegs + 1;
 1253                 ehdr->e_shentsize = sizeof(Elf_Shdr);
 1254                 ehdr->e_shnum = 0;
 1255                 ehdr->e_shstrndx = SHN_UNDEF;
 1256 
 1257                 /*
 1258                  * Fill in the program header entries.
 1259                  */
 1260                 phdr = (Elf_Phdr *)((char *)dst + phoff);
 1261 
 1262                 /* The note segement. */
 1263                 phdr->p_type = PT_NOTE;
 1264                 phdr->p_offset = noteoff;
 1265                 phdr->p_vaddr = 0;
 1266                 phdr->p_paddr = 0;
 1267                 phdr->p_filesz = notesz;
 1268                 phdr->p_memsz = 0;
 1269                 phdr->p_flags = 0;
 1270                 phdr->p_align = 0;
 1271                 phdr++;
 1272 
 1273                 /* All the writable segments from the program. */
 1274                 phc.phdr = phdr;
 1275                 phc.offset = *off;
 1276                 each_writable_segment(td, cb_put_phdr, &phc);
 1277         }
 1278 }
 1279 
 1280 static void
 1281 __elfN(putnote)(void *dst, size_t *off, const char *name, int type,
 1282     const void *desc, size_t descsz)
 1283 {
 1284         Elf_Note note;
 1285 
 1286         note.n_namesz = strlen(name) + 1;
 1287         note.n_descsz = descsz;
 1288         note.n_type = type;
 1289         if (dst != NULL)
 1290                 bcopy(&note, (char *)dst + *off, sizeof note);
 1291         *off += sizeof note;
 1292         if (dst != NULL)
 1293                 bcopy(name, (char *)dst + *off, note.n_namesz);
 1294         *off += roundup2(note.n_namesz, sizeof(Elf_Size));
 1295         if (dst != NULL)
 1296                 bcopy(desc, (char *)dst + *off, note.n_descsz);
 1297         *off += roundup2(note.n_descsz, sizeof(Elf_Size));
 1298 }
 1299 
 1300 /*
 1301  * Tell kern_execve.c about it, with a little help from the linker.
 1302  */
 1303 static struct execsw __elfN(execsw) = {
 1304         __CONCAT(exec_, __elfN(imgact)),
 1305         __XSTRING(__CONCAT(ELF, __ELF_WORD_SIZE))
 1306 };
 1307 EXEC_SET(__CONCAT(elf, __ELF_WORD_SIZE), __elfN(execsw));

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