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

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    1 /*-
    2  * Copyright (c) 1995-1996 Søren Schmidt
    3  * Copyright (c) 1996 Peter Wemm
    4  * All rights reserved.
    5  *
    6  * Redistribution and use in source and binary forms, with or without
    7  * modification, are permitted provided that the following conditions
    8  * are met:
    9  * 1. Redistributions of source code must retain the above copyright
   10  *    notice, this list of conditions and the following disclaimer
   11  *    in this position and unchanged.
   12  * 2. Redistributions in binary form must reproduce the above copyright
   13  *    notice, this list of conditions and the following disclaimer in the
   14  *    documentation and/or other materials provided with the distribution.
   15  * 3. The name of the author may not be used to endorse or promote products
   16  *    derived from this software withough specific prior written permission
   17  *
   18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
   19  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   20  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
   21  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
   22  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
   23  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
   24  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
   25  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
   27  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   28  *
   29  * $FreeBSD: src/sys/kern/imgact_elf.c,v 1.73.2.13 2002/12/28 19:49:41 dillon Exp $
   30  * $DragonFly: src/sys/kern/imgact_elf.c,v 1.55 2008/08/17 17:21:36 nth Exp $
   31  */
   32 
   33 #include <sys/param.h>
   34 #include <sys/exec.h>
   35 #include <sys/fcntl.h>
   36 #include <sys/file.h>
   37 #include <sys/imgact.h>
   38 #include <sys/imgact_elf.h>
   39 #include <sys/kernel.h>
   40 #include <sys/malloc.h>
   41 #include <sys/mman.h>
   42 #include <sys/systm.h>
   43 #include <sys/proc.h>
   44 #include <sys/nlookup.h>
   45 #include <sys/pioctl.h>
   46 #include <sys/procfs.h>
   47 #include <sys/resourcevar.h>
   48 #include <sys/signalvar.h>
   49 #include <sys/stat.h>
   50 #include <sys/syscall.h>
   51 #include <sys/sysctl.h>
   52 #include <sys/sysent.h>
   53 #include <sys/vnode.h>
   54 #include <sys/sfbuf.h>
   55 
   56 #include <vm/vm.h>
   57 #include <vm/vm_kern.h>
   58 #include <vm/vm_param.h>
   59 #include <vm/pmap.h>
   60 #include <sys/lock.h>
   61 #include <vm/vm_map.h>
   62 #include <vm/vm_object.h>
   63 #include <vm/vm_extern.h>
   64 
   65 #include <machine/elf.h>
   66 #include <machine/md_var.h>
   67 #include <sys/mount.h>
   68 #include <sys/ckpt.h>
   69 #define OLD_EI_BRAND    8
   70 
   71 __ElfType(Brandinfo);
   72 __ElfType(Auxargs);
   73 
   74 static int elf_check_header (const Elf_Ehdr *hdr);
   75 static int elf_freebsd_fixup (register_t **stack_base,
   76     struct image_params *imgp);
   77 static int elf_load_file (struct proc *p, const char *file, u_long *addr,
   78     u_long *entry);
   79 static int elf_load_section (struct proc *p,
   80     struct vmspace *vmspace, struct vnode *vp,
   81     vm_offset_t offset, caddr_t vmaddr, size_t memsz, size_t filsz,
   82     vm_prot_t prot);
   83 static int exec_elf_imgact (struct image_params *imgp);
   84 
   85 static int elf_trace = 0;
   86 SYSCTL_INT(_debug, OID_AUTO, elf_trace, CTLFLAG_RW, &elf_trace, 0, "");
   87 static int elf_legacy_coredump = 0;
   88 SYSCTL_INT(_debug, OID_AUTO, elf_legacy_coredump, CTLFLAG_RW,
   89     &elf_legacy_coredump, 0, "");
   90 
   91 static int dragonfly_match_abi_note(const Elf_Note *);
   92 static int freebsd_match_abi_note(const Elf_Note *);
   93 
   94 static struct sysentvec elf_freebsd_sysvec = {
   95         SYS_MAXSYSCALL,
   96         sysent,
   97         -1,
   98         0,
   99         0,
  100         0,
  101         0,
  102         0,
  103         elf_freebsd_fixup,
  104         sendsig,
  105         sigcode,
  106         &szsigcode,
  107         0,
  108         "FreeBSD ELF",
  109         elf_coredump,
  110         NULL,
  111         MINSIGSTKSZ
  112 };
  113 
  114 static Elf_Brandinfo freebsd_brand_info = {
  115                                                 ELFOSABI_FREEBSD,
  116                                                 "FreeBSD",
  117                                                 freebsd_match_abi_note,
  118                                                 "",
  119                                                 "/usr/libexec/ld-elf.so.1",
  120                                                 &elf_freebsd_sysvec
  121                                           };
  122 
  123 static Elf_Brandinfo dragonfly_brand_info = {
  124                                                 ELFOSABI_NONE,
  125                                                 "DragonFly",
  126                                                 dragonfly_match_abi_note,
  127                                                 "",
  128                                                 "/usr/libexec/ld-elf.so.2",
  129                                                 &elf_freebsd_sysvec
  130                                           };
  131 
  132 static Elf_Brandinfo *elf_brand_list[MAX_BRANDS] = {
  133                                                         &dragonfly_brand_info,
  134                                                         &freebsd_brand_info,
  135                                                         NULL, NULL, NULL,
  136                                                         NULL, NULL, NULL
  137                                                     };
  138 
  139 static int
  140 freebsd_match_abi_note(const Elf_Note *abi_note)
  141 {
  142         const char *abi_name = (const char *)
  143             ((const uint8_t *)abi_note + sizeof(*abi_note));
  144 
  145         if (abi_note->n_namesz != sizeof("FreeBSD"))
  146                 return(FALSE);
  147         if (memcmp(abi_name, "FreeBSD", sizeof("FreeBSD")))
  148                 return(FALSE);
  149         return(TRUE);
  150 }
  151 
  152 static int
  153 dragonfly_match_abi_note(const Elf_Note *abi_note)
  154 {
  155         const char *abi_name = (const char *)
  156             ((const uint8_t *)abi_note + sizeof(*abi_note));
  157 
  158         if (abi_note->n_namesz != sizeof("DragonFly"))
  159                 return(FALSE);
  160         if (memcmp(abi_name, "DragonFly", sizeof("DragonFly")))
  161                 return(FALSE);
  162         return(TRUE);
  163 }
  164 
  165 int
  166 elf_insert_brand_entry(Elf_Brandinfo *entry)
  167 {
  168         int i;
  169 
  170         for (i=1; i<MAX_BRANDS; i++) {
  171                 if (elf_brand_list[i] == NULL) {
  172                         elf_brand_list[i] = entry;
  173                         break;
  174                 }
  175         }
  176         if (i == MAX_BRANDS)
  177                 return -1;
  178         return 0;
  179 }
  180 
  181 int
  182 elf_remove_brand_entry(Elf_Brandinfo *entry)
  183 {
  184         int i;
  185 
  186         for (i=1; i<MAX_BRANDS; i++) {
  187                 if (elf_brand_list[i] == entry) {
  188                         elf_brand_list[i] = NULL;
  189                         break;
  190                 }
  191         }
  192         if (i == MAX_BRANDS)
  193                 return -1;
  194         return 0;
  195 }
  196 
  197 /*
  198  * Check if an elf brand is being used anywhere in the system.
  199  *
  200  * Used by the linux emulation module unloader.  This isn't safe from
  201  * races.
  202  */
  203 struct elf_brand_inuse_info {
  204         int rval;
  205         Elf_Brandinfo *entry;
  206 };
  207 
  208 static int elf_brand_inuse_callback(struct proc *p, void *data);
  209 
  210 int
  211 elf_brand_inuse(Elf_Brandinfo *entry)
  212 {
  213         struct elf_brand_inuse_info info;
  214 
  215         info.rval = FALSE;
  216         info.entry = entry;
  217         allproc_scan(elf_brand_inuse_callback, entry);
  218         return (info.rval);
  219 }
  220 
  221 static
  222 int
  223 elf_brand_inuse_callback(struct proc *p, void *data)
  224 {
  225         struct elf_brand_inuse_info *info = data;
  226 
  227         if (p->p_sysent == info->entry->sysvec) {
  228                 info->rval = TRUE;
  229                 return(-1);
  230         }
  231         return(0);
  232 }
  233 
  234 static int
  235 elf_check_header(const Elf_Ehdr *hdr)
  236 {
  237         if (!IS_ELF(*hdr) ||
  238             hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS ||
  239             hdr->e_ident[EI_DATA] != ELF_TARG_DATA ||
  240             hdr->e_ident[EI_VERSION] != EV_CURRENT ||
  241             hdr->e_phentsize != sizeof(Elf_Phdr) ||
  242             hdr->e_ehsize != sizeof(Elf_Ehdr) ||
  243             hdr->e_version != ELF_TARG_VER)
  244                 return ENOEXEC;
  245 
  246         if (!ELF_MACHINE_OK(hdr->e_machine))
  247                 return ENOEXEC;
  248 
  249         return 0;
  250 }
  251 
  252 static int
  253 elf_load_section(struct proc *p, struct vmspace *vmspace, struct vnode *vp, 
  254                  vm_offset_t offset, caddr_t vmaddr, size_t memsz,
  255                  size_t filsz, vm_prot_t prot)
  256 {
  257         size_t map_len;
  258         vm_offset_t map_addr;
  259         int error, rv, cow;
  260         int count;
  261         size_t copy_len;
  262         vm_object_t object;
  263         vm_offset_t file_addr;
  264 
  265         object = vp->v_object;
  266         error = 0;
  267 
  268         /*
  269          * It's necessary to fail if the filsz + offset taken from the
  270          * header is greater than the actual file pager object's size.
  271          * If we were to allow this, then the vm_map_find() below would
  272          * walk right off the end of the file object and into the ether.
  273          *
  274          * While I'm here, might as well check for something else that
  275          * is invalid: filsz cannot be greater than memsz.
  276          */
  277         if ((off_t)filsz + offset > vp->v_filesize || filsz > memsz) {
  278                 uprintf("elf_load_section: truncated ELF file\n");
  279                 return (ENOEXEC);
  280         }
  281 
  282         map_addr = trunc_page((vm_offset_t)vmaddr);
  283         file_addr = trunc_page(offset);
  284 
  285         /*
  286          * We have two choices.  We can either clear the data in the last page
  287          * of an oversized mapping, or we can start the anon mapping a page
  288          * early and copy the initialized data into that first page.  We
  289          * choose the second..
  290          */
  291         if (memsz > filsz)
  292                 map_len = trunc_page(offset+filsz) - file_addr;
  293         else
  294                 map_len = round_page(offset+filsz) - file_addr;
  295 
  296         if (map_len != 0) {
  297                 vm_object_reference(object);
  298 
  299                 /* cow flags: don't dump readonly sections in core */
  300                 cow = MAP_COPY_ON_WRITE | MAP_PREFAULT |
  301                     (prot & VM_PROT_WRITE ? 0 : MAP_DISABLE_COREDUMP);
  302 
  303                 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
  304                 vm_map_lock(&vmspace->vm_map);
  305                 rv = vm_map_insert(&vmspace->vm_map, &count,
  306                                       object,
  307                                       file_addr,        /* file offset */
  308                                       map_addr,         /* virtual start */
  309                                       map_addr + map_len,/* virtual end */
  310                                       VM_MAPTYPE_NORMAL,
  311                                       prot, VM_PROT_ALL,
  312                                       cow);
  313                 vm_map_unlock(&vmspace->vm_map);
  314                 vm_map_entry_release(count);
  315                 if (rv != KERN_SUCCESS) {
  316                         vm_object_deallocate(object);
  317                         return EINVAL;
  318                 }
  319 
  320                 /* we can stop now if we've covered it all */
  321                 if (memsz == filsz) {
  322                         return 0;
  323                 }
  324         }
  325 
  326 
  327         /*
  328          * We have to get the remaining bit of the file into the first part
  329          * of the oversized map segment.  This is normally because the .data
  330          * segment in the file is extended to provide bss.  It's a neat idea
  331          * to try and save a page, but it's a pain in the behind to implement.
  332          */
  333         copy_len = (offset + filsz) - trunc_page(offset + filsz);
  334         map_addr = trunc_page((vm_offset_t)vmaddr + filsz);
  335         map_len = round_page((vm_offset_t)vmaddr + memsz) - map_addr;
  336 
  337         /* This had damn well better be true! */
  338         if (map_len != 0) {
  339                 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
  340                 vm_map_lock(&vmspace->vm_map);
  341                 rv = vm_map_insert(&vmspace->vm_map, &count,
  342                                         NULL, 0,
  343                                         map_addr, map_addr + map_len,
  344                                         VM_MAPTYPE_NORMAL,
  345                                         VM_PROT_ALL, VM_PROT_ALL,
  346                                         0);
  347                 vm_map_unlock(&vmspace->vm_map);
  348                 vm_map_entry_release(count);
  349                 if (rv != KERN_SUCCESS) {
  350                         return EINVAL; 
  351                 }
  352         }
  353 
  354         if (copy_len != 0) {
  355                 vm_page_t m;
  356                 struct sf_buf *sf;
  357 
  358                 m = vm_fault_object_page(object, trunc_page(offset + filsz),
  359                                          VM_PROT_READ, 0, &error);
  360                 if (m) {
  361                         sf = sf_buf_alloc(m, SFB_CPUPRIVATE);
  362                         error = copyout((caddr_t)sf_buf_kva(sf),
  363                                         (caddr_t)map_addr, copy_len);
  364                         sf_buf_free(sf);
  365                         vm_page_unhold(m);
  366                 }
  367                 if (error) {
  368                         return (error);
  369                 }
  370         }
  371 
  372         /*
  373          * set it to the specified protection
  374          */
  375         vm_map_protect(&vmspace->vm_map, map_addr, map_addr + map_len,  prot,
  376                        FALSE);
  377 
  378         return error;
  379 }
  380 
  381 /*
  382  * Load the file "file" into memory.  It may be either a shared object
  383  * or an executable.
  384  *
  385  * The "addr" reference parameter is in/out.  On entry, it specifies
  386  * the address where a shared object should be loaded.  If the file is
  387  * an executable, this value is ignored.  On exit, "addr" specifies
  388  * where the file was actually loaded.
  389  *
  390  * The "entry" reference parameter is out only.  On exit, it specifies
  391  * the entry point for the loaded file.
  392  */
  393 static int
  394 elf_load_file(struct proc *p, const char *file, u_long *addr, u_long *entry)
  395 {
  396         struct {
  397                 struct nlookupdata nd;
  398                 struct vattr attr;
  399                 struct image_params image_params;
  400         } *tempdata;
  401         const Elf_Ehdr *hdr = NULL;
  402         const Elf_Phdr *phdr = NULL;
  403         struct nlookupdata *nd;
  404         struct vmspace *vmspace = p->p_vmspace;
  405         struct vattr *attr;
  406         struct image_params *imgp;
  407         vm_prot_t prot;
  408         u_long rbase;
  409         u_long base_addr = 0;
  410         int error, i, numsegs;
  411 
  412         tempdata = kmalloc(sizeof(*tempdata), M_TEMP, M_WAITOK);
  413         nd = &tempdata->nd;
  414         attr = &tempdata->attr;
  415         imgp = &tempdata->image_params;
  416 
  417         /*
  418          * Initialize part of the common data
  419          */
  420         imgp->proc = p;
  421         imgp->attr = attr;
  422         imgp->firstpage = NULL;
  423         imgp->image_header = NULL;
  424         imgp->vp = NULL;
  425 
  426         error = nlookup_init(nd, file, UIO_SYSSPACE, NLC_FOLLOW);
  427         if (error == 0)
  428                 error = nlookup(nd);
  429         if (error == 0)
  430                 error = cache_vget(&nd->nl_nch, nd->nl_cred, LK_EXCLUSIVE, &imgp->vp);
  431         nlookup_done(nd);
  432         if (error)
  433                 goto fail;
  434 
  435         /*
  436          * Check permissions, modes, uid, etc on the file, and "open" it.
  437          */
  438         error = exec_check_permissions(imgp);
  439         if (error) {
  440                 vn_unlock(imgp->vp);
  441                 goto fail;
  442         }
  443 
  444         error = exec_map_first_page(imgp);
  445         /*
  446          * Also make certain that the interpreter stays the same, so set
  447          * its VTEXT flag, too.
  448          */
  449         if (error == 0)
  450                 imgp->vp->v_flag |= VTEXT;
  451         vn_unlock(imgp->vp);
  452         if (error)
  453                 goto fail;
  454 
  455         hdr = (const Elf_Ehdr *)imgp->image_header;
  456         if ((error = elf_check_header(hdr)) != 0)
  457                 goto fail;
  458         if (hdr->e_type == ET_DYN)
  459                 rbase = *addr;
  460         else if (hdr->e_type == ET_EXEC)
  461                 rbase = 0;
  462         else {
  463                 error = ENOEXEC;
  464                 goto fail;
  465         }
  466 
  467         /* Only support headers that fit within first page for now
  468          * (multiplication of two Elf_Half fields will not overflow) */
  469         if ((hdr->e_phoff > PAGE_SIZE) ||
  470             (hdr->e_phentsize * hdr->e_phnum) > PAGE_SIZE - hdr->e_phoff) {
  471                 error = ENOEXEC;
  472                 goto fail;
  473         }
  474 
  475         phdr = (const Elf_Phdr *)(imgp->image_header + hdr->e_phoff);
  476 
  477         for (i = 0, numsegs = 0; i < hdr->e_phnum; i++) {
  478                 if (phdr[i].p_type == PT_LOAD) {        /* Loadable segment */
  479                         prot = 0;
  480                         if (phdr[i].p_flags & PF_X)
  481                                 prot |= VM_PROT_EXECUTE;
  482                         if (phdr[i].p_flags & PF_W)
  483                                 prot |= VM_PROT_WRITE;
  484                         if (phdr[i].p_flags & PF_R)
  485                                 prot |= VM_PROT_READ;
  486 
  487                         error = elf_load_section(
  488                                     p, vmspace, imgp->vp,
  489                                     phdr[i].p_offset,
  490                                     (caddr_t)phdr[i].p_vaddr +
  491                                     rbase,
  492                                     phdr[i].p_memsz,
  493                                     phdr[i].p_filesz, prot);
  494                         if (error != 0)
  495                                 goto fail;
  496                         /*
  497                          * Establish the base address if this is the
  498                          * first segment.
  499                          */
  500                         if (numsegs == 0)
  501                                 base_addr = trunc_page(phdr[i].p_vaddr + rbase);
  502                         numsegs++;
  503                 }
  504         }
  505         *addr = base_addr;
  506         *entry=(unsigned long)hdr->e_entry + rbase;
  507 
  508 fail:
  509         if (imgp->firstpage)
  510                 exec_unmap_first_page(imgp);
  511         if (imgp->vp) {
  512                 vrele(imgp->vp);
  513                 imgp->vp = NULL;
  514         }
  515         kfree(tempdata, M_TEMP);
  516 
  517         return error;
  518 }
  519 
  520 /*
  521  * non static, as it can be overridden by start_init()
  522  */
  523 int fallback_elf_brand = -1;
  524 SYSCTL_INT(_kern, OID_AUTO, fallback_elf_brand, CTLFLAG_RW,
  525                 &fallback_elf_brand, -1,
  526                 "ELF brand of last resort");
  527 
  528 static int
  529 exec_elf_imgact(struct image_params *imgp)
  530 {
  531         const Elf_Ehdr *hdr = (const Elf_Ehdr *) imgp->image_header;
  532         const Elf_Phdr *phdr;
  533         Elf_Auxargs *elf_auxargs = NULL;
  534         struct vmspace *vmspace;
  535         vm_prot_t prot;
  536         u_long text_size = 0, data_size = 0, total_size = 0;
  537         u_long text_addr = 0, data_addr = 0;
  538         u_long seg_size, seg_addr;
  539         u_long addr, entry = 0, proghdr = 0;
  540         int error, i;
  541         const char *interp = NULL;
  542         const Elf_Note *abi_note = NULL;
  543         Elf_Brandinfo *brand_info;
  544         char *path;
  545 
  546         error = 0;
  547 
  548         /*
  549          * Do we have a valid ELF header ?
  550          */
  551         if (elf_check_header(hdr) != 0 || hdr->e_type != ET_EXEC)
  552                 return -1;
  553 
  554         /*
  555          * From here on down, we return an errno, not -1, as we've
  556          * detected an ELF file.
  557          */
  558 
  559         if ((hdr->e_phoff > PAGE_SIZE) ||
  560             (hdr->e_phoff + hdr->e_phentsize * hdr->e_phnum) > PAGE_SIZE) {
  561                 /* Only support headers in first page for now */
  562                 return ENOEXEC;
  563         }
  564         phdr = (const Elf_Phdr*)(imgp->image_header + hdr->e_phoff);
  565         
  566         /*
  567          * From this point on, we may have resources that need to be freed.
  568          */
  569 
  570         exec_new_vmspace(imgp, NULL);
  571 
  572         /*
  573          * Yeah, I'm paranoid.  There is every reason in the world to get
  574          * VTEXT now since from here on out, there are places we can have
  575          * a context switch.  Better safe than sorry; I really don't want
  576          * the file to change while it's being loaded.
  577          */
  578         vsetflags(imgp->vp, VTEXT);
  579 
  580         vmspace = imgp->proc->p_vmspace;
  581 
  582         for (i = 0; i < hdr->e_phnum; i++) {
  583                 switch(phdr[i].p_type) {
  584 
  585                 case PT_LOAD:   /* Loadable segment */
  586                         prot = 0;
  587                         if (phdr[i].p_flags & PF_X)
  588                                 prot |= VM_PROT_EXECUTE;
  589                         if (phdr[i].p_flags & PF_W)
  590                                 prot |= VM_PROT_WRITE;
  591                         if (phdr[i].p_flags & PF_R)
  592                                 prot |= VM_PROT_READ;
  593 
  594                         if ((error = elf_load_section(imgp->proc,
  595                                                      vmspace, imgp->vp,
  596                                                      phdr[i].p_offset,
  597                                                      (caddr_t)phdr[i].p_vaddr,
  598                                                      phdr[i].p_memsz,
  599                                                      phdr[i].p_filesz, prot)) != 0)
  600                                 goto fail;
  601 
  602                         /*
  603                          * If this segment contains the program headers,
  604                          * remember their virtual address for the AT_PHDR
  605                          * aux entry. Static binaries don't usually include
  606                          * a PT_PHDR entry.
  607                          */
  608                         if (phdr[i].p_offset == 0 &&
  609                             hdr->e_phoff + hdr->e_phnum * hdr->e_phentsize
  610                                 <= phdr[i].p_filesz)
  611                                 proghdr = phdr[i].p_vaddr + hdr->e_phoff;
  612 
  613                         seg_addr = trunc_page(phdr[i].p_vaddr);
  614                         seg_size = round_page(phdr[i].p_memsz +
  615                                 phdr[i].p_vaddr - seg_addr);
  616 
  617                         /*
  618                          * Is this .text or .data?  We can't use
  619                          * VM_PROT_WRITE or VM_PROT_EXEC, it breaks the
  620                          * alpha terribly and possibly does other bad
  621                          * things so we stick to the old way of figuring
  622                          * it out:  If the segment contains the program
  623                          * entry point, it's a text segment, otherwise it
  624                          * is a data segment.
  625                          *
  626                          * Note that obreak() assumes that data_addr + 
  627                          * data_size == end of data load area, and the ELF
  628                          * file format expects segments to be sorted by
  629                          * address.  If multiple data segments exist, the
  630                          * last one will be used.
  631                          */
  632                         if (hdr->e_entry >= phdr[i].p_vaddr &&
  633                             hdr->e_entry < (phdr[i].p_vaddr +
  634                             phdr[i].p_memsz)) {
  635                                 text_size = seg_size;
  636                                 text_addr = seg_addr;
  637                                 entry = (u_long)hdr->e_entry;
  638                         } else {
  639                                 data_size = seg_size;
  640                                 data_addr = seg_addr;
  641                         }
  642                         total_size += seg_size;
  643 
  644                         /*
  645                          * Check limits.  It should be safe to check the
  646                          * limits after loading the segment since we do
  647                          * not actually fault in all the segment's pages.
  648                          */
  649                         if (data_size >
  650                             imgp->proc->p_rlimit[RLIMIT_DATA].rlim_cur ||
  651                             text_size > maxtsiz ||
  652                             total_size >
  653                             imgp->proc->p_rlimit[RLIMIT_VMEM].rlim_cur) {
  654                                 error = ENOMEM;
  655                                 goto fail;
  656                         }
  657                         break;
  658                 case PT_INTERP: /* Path to interpreter */
  659                         if (phdr[i].p_filesz > MAXPATHLEN ||
  660                             phdr[i].p_offset + phdr[i].p_filesz > PAGE_SIZE) {
  661                                 error = ENOEXEC;
  662                                 goto fail;
  663                         }
  664                         interp = imgp->image_header + phdr[i].p_offset;
  665                         break;
  666                 case PT_NOTE:   /* Check for .note.ABI-tag */
  667                 {
  668                         const Elf_Note *tmp_note;
  669                         /* XXX handle anything outside the first page */
  670                         if (phdr[i].p_offset + phdr[i].p_filesz > PAGE_SIZE)
  671                                 continue;
  672                         if (phdr[i].p_filesz < sizeof(Elf_Note))
  673                                 continue; /* ENOEXEC? */
  674                         tmp_note = (const Elf_Note *)(imgp->image_header + phdr[i].p_offset);
  675                         if (tmp_note->n_type != 1)
  676                                 continue;
  677                         if (tmp_note->n_namesz + sizeof(Elf_Note) +
  678                             tmp_note->n_descsz > phdr[i].p_filesz)
  679                                 continue; /* ENOEXEC? */
  680                         abi_note = tmp_note;
  681                 }       
  682                         break;
  683                 case PT_PHDR:   /* Program header table info */
  684                         proghdr = phdr[i].p_vaddr;
  685                         break;
  686                 default:
  687                         break;
  688                 }
  689         }
  690 
  691         vmspace->vm_tsize = text_size >> PAGE_SHIFT;
  692         vmspace->vm_taddr = (caddr_t)(uintptr_t)text_addr;
  693         vmspace->vm_dsize = data_size >> PAGE_SHIFT;
  694         vmspace->vm_daddr = (caddr_t)(uintptr_t)data_addr;
  695 
  696         addr = ELF_RTLD_ADDR(vmspace);
  697 
  698         imgp->entry_addr = entry;
  699 
  700         brand_info = NULL;
  701 
  702         /* We support three types of branding -- (1) the ELF EI_OSABI field
  703          * that SCO added to the ELF spec, (2) FreeBSD 3.x's traditional string
  704          * branding w/in the ELF header, and (3) path of the `interp_path'
  705          * field.  We should also look for an ".note.ABI-tag" ELF section now
  706          * in all Linux ELF binaries, FreeBSD 4.1+, and some NetBSD ones.
  707          */
  708 
  709         /* If the executable has a brand, search for it in the brand list. */
  710         if (brand_info == NULL && hdr->e_ident[EI_OSABI] != ELFOSABI_NONE) {
  711                 for (i = 0;  i < MAX_BRANDS;  i++) {
  712                         Elf_Brandinfo *bi = elf_brand_list[i];
  713 
  714                         if (bi != NULL && 
  715                             (hdr->e_ident[EI_OSABI] == bi->brand
  716                             || 0 == 
  717                             strncmp((const char *)&hdr->e_ident[OLD_EI_BRAND], 
  718                             bi->compat_3_brand, strlen(bi->compat_3_brand)))) {
  719                                 brand_info = bi;
  720                                 break;
  721                         }
  722                 }
  723         }
  724 
  725         /* Search for a recognized ABI. */
  726         if (brand_info == NULL && abi_note != NULL) {
  727                 for (i = 0; i < MAX_BRANDS; i++) {
  728                         Elf_Brandinfo *bi = elf_brand_list[i];
  729 
  730                         if (bi != NULL && bi->match_abi_note != NULL &&
  731                             (*bi->match_abi_note)(abi_note)) {
  732                                 brand_info = bi;
  733                                 break;
  734                         }
  735                 }
  736         }
  737 
  738         /*
  739          * ELFOSABI_NONE == ELFOSABI_SYSV, so a SYSV binary misses all
  740          * checks so far, since it is neither branded nor does it have
  741          * an ABI note.  If the EI_OSABI field is ELFOSABI_NONE, assume
  742          * it is svr4 and look for an entry in the elf_brand_list with
  743          * match_abi_note == NULL.
  744          */
  745         if (brand_info == NULL && hdr->e_ident[EI_OSABI] == ELFOSABI_NONE) {
  746                 for (i = 0; i < MAX_BRANDS; i++) {
  747                         Elf_Brandinfo *bi = elf_brand_list[i];
  748 
  749                         if (bi != NULL && bi->match_abi_note == NULL &&
  750                             ELFOSABI_SYSV == bi->brand) {
  751                                 brand_info = bi;
  752                                 break;
  753                         }
  754                 }
  755         }
  756 
  757         /* Lacking a recognized ABI, search for a recognized interpreter. */
  758         if (brand_info == NULL && interp != NULL) {
  759                 for (i = 0;  i < MAX_BRANDS;  i++) {
  760                         Elf_Brandinfo *bi = elf_brand_list[i];
  761 
  762                         if (bi != NULL &&
  763                             strcmp(interp, bi->interp_path) == 0) {
  764                                 brand_info = bi;
  765                                 break;
  766                         }
  767                 }
  768         }
  769 
  770         /* Lacking a recognized interpreter, try the default brand */
  771         if (brand_info == NULL) {
  772                 for (i = 0; i < MAX_BRANDS; i++) {
  773                         Elf_Brandinfo *bi = elf_brand_list[i];
  774 
  775                         if (bi != NULL && fallback_elf_brand == bi->brand) {
  776                                 brand_info = bi;
  777                                 break;
  778                         }
  779                 }
  780         }
  781 
  782         if (brand_info == NULL) {
  783                 uprintf("ELF binary type \"%u\" not known.\n",
  784                     hdr->e_ident[EI_OSABI]);
  785                 error = ENOEXEC;
  786                 goto fail;
  787         }
  788 
  789         imgp->proc->p_sysent = brand_info->sysvec;
  790         if (interp != NULL) {
  791                 path = kmalloc(MAXPATHLEN, M_TEMP, M_WAITOK);
  792                 ksnprintf(path, MAXPATHLEN, "%s%s",
  793                          brand_info->emul_path, interp);
  794                 if ((error = elf_load_file(imgp->proc, path, &addr,
  795                                            &imgp->entry_addr)) != 0) {
  796                         if ((error = elf_load_file(imgp->proc, interp, &addr,
  797                                                    &imgp->entry_addr)) != 0) {
  798                                 uprintf("ELF interpreter %s not found\n", path);
  799                                 kfree(path, M_TEMP);
  800                                 goto fail;
  801                         }
  802                 }
  803                 kfree(path, M_TEMP);
  804         } else {
  805                 addr = 0;
  806         }
  807 
  808         /*
  809          * Construct auxargs table (used by the fixup routine)
  810          */
  811         elf_auxargs = kmalloc(sizeof(Elf_Auxargs), M_TEMP, M_WAITOK);
  812         elf_auxargs->execfd = -1;
  813         elf_auxargs->phdr = proghdr;
  814         elf_auxargs->phent = hdr->e_phentsize;
  815         elf_auxargs->phnum = hdr->e_phnum;
  816         elf_auxargs->pagesz = PAGE_SIZE;
  817         elf_auxargs->base = addr;
  818         elf_auxargs->flags = 0;
  819         elf_auxargs->entry = entry;
  820         elf_auxargs->trace = elf_trace;
  821 
  822         imgp->auxargs = elf_auxargs;
  823         imgp->interpreted = 0;
  824 
  825 fail:
  826         return error;
  827 }
  828 
  829 static int
  830 elf_freebsd_fixup(register_t **stack_base, struct image_params *imgp)
  831 {
  832         Elf_Auxargs *args = (Elf_Auxargs *)imgp->auxargs;
  833         register_t *pos;
  834 
  835         pos = *stack_base + (imgp->args->argc + imgp->args->envc + 2);
  836 
  837         if (args->trace) {
  838                 AUXARGS_ENTRY(pos, AT_DEBUG, 1);
  839         }
  840         if (args->execfd != -1) {
  841                 AUXARGS_ENTRY(pos, AT_EXECFD, args->execfd);
  842         }
  843         AUXARGS_ENTRY(pos, AT_PHDR, args->phdr);
  844         AUXARGS_ENTRY(pos, AT_PHENT, args->phent);
  845         AUXARGS_ENTRY(pos, AT_PHNUM, args->phnum);
  846         AUXARGS_ENTRY(pos, AT_PAGESZ, args->pagesz);
  847         AUXARGS_ENTRY(pos, AT_FLAGS, args->flags);
  848         AUXARGS_ENTRY(pos, AT_ENTRY, args->entry);
  849         AUXARGS_ENTRY(pos, AT_BASE, args->base);
  850         AUXARGS_ENTRY(pos, AT_NULL, 0);
  851 
  852         kfree(imgp->auxargs, M_TEMP);
  853         imgp->auxargs = NULL;
  854 
  855         (*stack_base)--;
  856         suword(*stack_base, (long) imgp->args->argc);
  857         return 0;
  858 } 
  859 
  860 /*
  861  * Code for generating ELF core dumps.
  862  */
  863 
  864 typedef int (*segment_callback) (vm_map_entry_t, void *);
  865 
  866 /* Closure for cb_put_phdr(). */
  867 struct phdr_closure {
  868         Elf_Phdr *phdr;         /* Program header to fill in (incremented) */
  869         Elf_Phdr *phdr_max;     /* Pointer bound for error check */
  870         Elf_Off offset;         /* Offset of segment in core file */
  871 };
  872 
  873 /* Closure for cb_size_segment(). */
  874 struct sseg_closure {
  875         int count;              /* Count of writable segments. */
  876         size_t vsize;           /* Total size of all writable segments. */
  877 };
  878 
  879 /* Closure for cb_put_fp(). */
  880 struct fp_closure {
  881         struct vn_hdr *vnh;
  882         struct vn_hdr *vnh_max;
  883         int count;
  884         struct stat *sb;
  885 };
  886 
  887 typedef struct elf_buf {
  888         char    *buf;
  889         size_t  off;
  890         size_t  off_max;
  891 } *elf_buf_t;
  892 
  893 static void *target_reserve(elf_buf_t target, size_t bytes, int *error);
  894 
  895 static int cb_put_phdr (vm_map_entry_t, void *);
  896 static int cb_size_segment (vm_map_entry_t, void *);
  897 static int cb_fpcount_segment(vm_map_entry_t, void *);
  898 static int cb_put_fp(vm_map_entry_t, void *);
  899 
  900 
  901 static int each_segment (struct proc *, segment_callback, void *, int);
  902 static int elf_corehdr (struct lwp *, int, struct file *, struct ucred *,
  903                         int, elf_buf_t);
  904 enum putmode { WRITE, DRYRUN };
  905 static int elf_puthdr (struct lwp *, elf_buf_t, int sig, enum putmode,
  906                         int, struct file *);
  907 static int elf_putallnotes(struct lwp *, elf_buf_t, int, enum putmode);
  908 static int elf_putnote (elf_buf_t, const char *, int, const void *, size_t);
  909 
  910 static int elf_putsigs(struct lwp *, elf_buf_t);
  911 static int elf_puttextvp(struct proc *, elf_buf_t);
  912 static int elf_putfiles(struct proc *, elf_buf_t, struct file *);
  913 
  914 extern int osreldate;
  915 
  916 int
  917 elf_coredump(struct lwp *lp, int sig, struct vnode *vp, off_t limit)
  918 {
  919         struct file *fp; 
  920         int error;
  921 
  922         if ((error = falloc(NULL, &fp, NULL)) != 0)
  923                 return (error);
  924         fsetcred(fp, lp->lwp_proc->p_ucred);
  925 
  926         /*
  927          * XXX fixme.
  928          */
  929         fp->f_type = DTYPE_VNODE;
  930         fp->f_flag = O_CREAT|O_WRONLY|O_NOFOLLOW;
  931         fp->f_ops = &vnode_fileops;
  932         fp->f_data = vp;
  933         vn_unlock(vp);
  934         
  935         error = generic_elf_coredump(lp, sig, fp, limit);
  936 
  937         fp->f_type = 0;
  938         fp->f_flag = 0;
  939         fp->f_ops = &badfileops;
  940         fp->f_data = NULL;
  941         fdrop(fp);
  942         return (error);
  943 }
  944 
  945 int
  946 generic_elf_coredump(struct lwp *lp, int sig, struct file *fp, off_t limit)
  947 {
  948         struct proc *p = lp->lwp_proc;
  949         struct ucred *cred = p->p_ucred;
  950         int error = 0;
  951         struct sseg_closure seginfo;
  952         struct elf_buf target;
  953 
  954         if (!fp)
  955                 kprintf("can't dump core - null fp\n");
  956 
  957         /*
  958          * Size the program segments
  959          */
  960         seginfo.count = 0;
  961         seginfo.vsize = 0;
  962         each_segment(p, cb_size_segment, &seginfo, 1);
  963 
  964         /*
  965          * Calculate the size of the core file header area by making
  966          * a dry run of generating it.  Nothing is written, but the
  967          * size is calculated.
  968          */
  969         bzero(&target, sizeof(target));
  970         elf_puthdr(lp, &target, sig, DRYRUN, seginfo.count, fp);
  971 
  972         if (target.off + seginfo.vsize >= limit)
  973                 return (EFAULT);
  974 
  975         /*
  976          * Allocate memory for building the header, fill it up,
  977          * and write it out.
  978          */
  979         target.off_max = target.off;
  980         target.off = 0;
  981         target.buf = kmalloc(target.off_max, M_TEMP, M_WAITOK|M_ZERO);
  982 
  983         error = elf_corehdr(lp, sig, fp, cred, seginfo.count, &target);
  984 
  985         /* Write the contents of all of the writable segments. */
  986         if (error == 0) {
  987                 Elf_Phdr *php;
  988                 int i;
  989                 ssize_t nbytes;
  990 
  991                 php = (Elf_Phdr *)(target.buf + sizeof(Elf_Ehdr)) + 1;
  992                 for (i = 0; i < seginfo.count; i++) {
  993                         error = fp_write(fp, (caddr_t)php->p_vaddr,
  994                                         php->p_filesz, &nbytes, UIO_USERSPACE);
  995                         if (error != 0)
  996                                 break;
  997                         php++;
  998                 }
  999         }
 1000         kfree(target.buf, M_TEMP);
 1001         
 1002         return error;
 1003 }
 1004 
 1005 /*
 1006  * A callback for each_segment() to write out the segment's
 1007  * program header entry.
 1008  */
 1009 static int
 1010 cb_put_phdr(vm_map_entry_t entry, void *closure)
 1011 {
 1012         struct phdr_closure *phc = closure;
 1013         Elf_Phdr *phdr = phc->phdr;
 1014 
 1015         if (phc->phdr == phc->phdr_max)
 1016                 return EINVAL;
 1017 
 1018         phc->offset = round_page(phc->offset);
 1019 
 1020         phdr->p_type = PT_LOAD;
 1021         phdr->p_offset = phc->offset;
 1022         phdr->p_vaddr = entry->start;
 1023         phdr->p_paddr = 0;
 1024         phdr->p_filesz = phdr->p_memsz = entry->end - entry->start;
 1025         phdr->p_align = PAGE_SIZE;
 1026         phdr->p_flags = 0;
 1027         if (entry->protection & VM_PROT_READ)
 1028                 phdr->p_flags |= PF_R;
 1029         if (entry->protection & VM_PROT_WRITE)
 1030                 phdr->p_flags |= PF_W;
 1031         if (entry->protection & VM_PROT_EXECUTE)
 1032                 phdr->p_flags |= PF_X;
 1033 
 1034         phc->offset += phdr->p_filesz;
 1035         ++phc->phdr;
 1036         return 0;
 1037 }
 1038 
 1039 /*
 1040  * A callback for each_writable_segment() to gather information about
 1041  * the number of segments and their total size.
 1042  */
 1043 static int
 1044 cb_size_segment(vm_map_entry_t entry, void *closure)
 1045 {
 1046         struct sseg_closure *ssc = closure;
 1047 
 1048         ++ssc->count;
 1049         ssc->vsize += entry->end - entry->start;
 1050         return 0;
 1051 }
 1052 
 1053 /*
 1054  * A callback for each_segment() to gather information about
 1055  * the number of text segments.
 1056  */
 1057 static int
 1058 cb_fpcount_segment(vm_map_entry_t entry, void *closure)
 1059 {
 1060         int *count = closure;
 1061         struct vnode *vp;
 1062 
 1063         if (entry->object.vm_object->type == OBJT_VNODE) {
 1064                 vp = (struct vnode *)entry->object.vm_object->handle;
 1065                 if ((vp->v_flag & VCKPT) && curproc->p_textvp == vp)
 1066                         return 0;
 1067                 ++*count;
 1068         }
 1069         return 0;
 1070 }
 1071 
 1072 static int
 1073 cb_put_fp(vm_map_entry_t entry, void *closure) 
 1074 {
 1075         struct fp_closure *fpc = closure;
 1076         struct vn_hdr *vnh = fpc->vnh;
 1077         Elf_Phdr *phdr = &vnh->vnh_phdr;
 1078         struct vnode *vp;
 1079         int error;
 1080 
 1081         /*
 1082          * If an entry represents a vnode then write out a file handle.
 1083          *
 1084          * If we are checkpointing a checkpoint-restored program we do
 1085          * NOT record the filehandle for the old checkpoint vnode (which
 1086          * is mapped all over the place).  Instead we rely on the fact
 1087          * that a checkpoint-restored program does not mmap() the checkpt
 1088          * vnode NOCORE, so its contents will be written out to the
 1089          * new checkpoint file.  This is necessary because the 'old'
 1090          * checkpoint file is typically destroyed when a new one is created
 1091          * and thus cannot be used to restore the new checkpoint.
 1092          *
 1093          * Theoretically we could create a chain of checkpoint files and
 1094          * operate the checkpointing operation kinda like an incremental
 1095          * checkpoint, but a checkpoint restore would then likely wind up
 1096          * referencing many prior checkpoint files and that is a bit over
 1097          * the top for the purpose of the checkpoint API.
 1098          */
 1099         if (entry->object.vm_object->type == OBJT_VNODE) {
 1100                 vp = (struct vnode *)entry->object.vm_object->handle;
 1101                 if ((vp->v_flag & VCKPT) && curproc->p_textvp == vp)
 1102                         return 0;
 1103                 if (vnh == fpc->vnh_max)
 1104                         return EINVAL;
 1105 
 1106                 if (vp->v_mount)
 1107                         vnh->vnh_fh.fh_fsid = vp->v_mount->mnt_stat.f_fsid;
 1108                 error = VFS_VPTOFH(vp, &vnh->vnh_fh.fh_fid);
 1109                 if (error) {
 1110                         char *freepath, *fullpath;
 1111 
 1112                         if (vn_fullpath(curproc, vp, &fullpath, &freepath)) {
 1113                                 kprintf("Warning: coredump, error %d: cannot store file handle for vnode %p\n", error, vp);
 1114                         } else {
 1115                                 kprintf("Warning: coredump, error %d: cannot store file handle for %s\n", error, fullpath);
 1116                                 kfree(freepath, M_TEMP);
 1117                         }
 1118                         error = 0;
 1119                 }
 1120 
 1121                 phdr->p_type = PT_LOAD;
 1122                 phdr->p_offset = 0;        /* not written to core */
 1123                 phdr->p_vaddr = entry->start;
 1124                 phdr->p_paddr = 0;
 1125                 phdr->p_filesz = phdr->p_memsz = entry->end - entry->start;
 1126                 phdr->p_align = PAGE_SIZE;
 1127                 phdr->p_flags = 0;
 1128                 if (entry->protection & VM_PROT_READ)
 1129                         phdr->p_flags |= PF_R;
 1130                 if (entry->protection & VM_PROT_WRITE)
 1131                         phdr->p_flags |= PF_W;
 1132                 if (entry->protection & VM_PROT_EXECUTE)
 1133                         phdr->p_flags |= PF_X;
 1134                 ++fpc->vnh;
 1135                 ++fpc->count;
 1136         }
 1137         return 0;
 1138 }
 1139 
 1140 /*
 1141  * For each writable segment in the process's memory map, call the given
 1142  * function with a pointer to the map entry and some arbitrary
 1143  * caller-supplied data.
 1144  */
 1145 static int
 1146 each_segment(struct proc *p, segment_callback func, void *closure, int writable)
 1147 {
 1148         int error = 0;
 1149         vm_map_t map = &p->p_vmspace->vm_map;
 1150         vm_map_entry_t entry;
 1151 
 1152         for (entry = map->header.next; error == 0 && entry != &map->header;
 1153             entry = entry->next) {
 1154                 vm_object_t obj;
 1155 
 1156                 /*
 1157                  * Don't dump inaccessible mappings, deal with legacy
 1158                  * coredump mode.
 1159                  *
 1160                  * Note that read-only segments related to the elf binary
 1161                  * are marked MAP_ENTRY_NOCOREDUMP now so we no longer
 1162                  * need to arbitrarily ignore such segments.
 1163                  */
 1164                 if (elf_legacy_coredump) {
 1165                         if (writable && (entry->protection & VM_PROT_RW) != VM_PROT_RW)
 1166                                 continue;
 1167                 } else {
 1168                         if (writable && (entry->protection & VM_PROT_ALL) == 0)
 1169                                 continue;
 1170                 }
 1171 
 1172                 /*
 1173                  * Dont include memory segment in the coredump if
 1174                  * MAP_NOCORE is set in mmap(2) or MADV_NOCORE in
 1175                  * madvise(2).
 1176                  *
 1177                  * Currently we only dump normal VM object maps.  We do
 1178                  * not dump submaps or virtual page tables.
 1179                  */
 1180                 if (writable && (entry->eflags & MAP_ENTRY_NOCOREDUMP))
 1181                         continue;
 1182                 if (entry->maptype != VM_MAPTYPE_NORMAL)
 1183                         continue;
 1184                 if ((obj = entry->object.vm_object) == NULL)
 1185                         continue;
 1186 
 1187                 /* Find the deepest backing object. */
 1188                 while (obj->backing_object != NULL)
 1189                         obj = obj->backing_object;
 1190 
 1191                 /* Ignore memory-mapped devices and such things. */
 1192                 if (obj->type != OBJT_DEFAULT &&
 1193                     obj->type != OBJT_SWAP &&
 1194                     obj->type != OBJT_VNODE)
 1195                         continue;
 1196 
 1197                 error = (*func)(entry, closure);
 1198         }
 1199         return error;
 1200 }
 1201 
 1202 static
 1203 void *
 1204 target_reserve(elf_buf_t target, size_t bytes, int *error)
 1205 {
 1206     void *res = NULL;
 1207 
 1208     if (target->buf) {
 1209             if (target->off + bytes > target->off_max)
 1210                     *error = EINVAL;
 1211             else
 1212                     res = target->buf + target->off;
 1213     }
 1214     target->off += bytes;
 1215     return (res);
 1216 }
 1217 
 1218 /*
 1219  * Write the core file header to the file, including padding up to
 1220  * the page boundary.
 1221  */
 1222 static int
 1223 elf_corehdr(struct lwp *lp, int sig, struct file *fp, struct ucred *cred,
 1224             int numsegs, elf_buf_t target)
 1225 {
 1226         int error;
 1227         ssize_t nbytes;
 1228 
 1229         /*
 1230          * Fill in the header.  The fp is passed so we can detect and flag
 1231          * a checkpoint file pointer within the core file itself, because
 1232          * it may not be restored from the same file handle.
 1233          */
 1234         error = elf_puthdr(lp, target, sig, WRITE, numsegs, fp);
 1235 
 1236         /* Write it to the core file. */
 1237         if (error == 0) {
 1238                 error = fp_write(fp, target->buf, target->off, &nbytes,
 1239                                  UIO_SYSSPACE);
 1240         }
 1241         return error;
 1242 }
 1243 
 1244 static int
 1245 elf_puthdr(struct lwp *lp, elf_buf_t target, int sig, enum putmode mode,
 1246     int numsegs, struct file *fp)
 1247 {
 1248         struct proc *p = lp->lwp_proc;
 1249         int error = 0;
 1250         size_t phoff;
 1251         size_t noteoff;
 1252         size_t notesz;
 1253         Elf_Ehdr *ehdr;
 1254         Elf_Phdr *phdr;
 1255 
 1256         ehdr = target_reserve(target, sizeof(Elf_Ehdr), &error);
 1257 
 1258         phoff = target->off;
 1259         phdr = target_reserve(target, (numsegs + 1) * sizeof(Elf_Phdr), &error);
 1260 
 1261         noteoff = target->off;
 1262         if (error == 0)
 1263                 elf_putallnotes(lp, target, sig, mode);
 1264         notesz = target->off - noteoff;
 1265 
 1266         /*
 1267          * put extra cruft for dumping process state here 
 1268          *  - we really want it be before all the program 
 1269          *    mappings
 1270          *  - we just need to update the offset accordingly
 1271          *    and GDB will be none the wiser.
 1272          */
 1273         if (error == 0)
 1274                 error = elf_puttextvp(p, target);
 1275         if (error == 0)
 1276                 error = elf_putsigs(lp, target);
 1277         if (error == 0)
 1278                 error = elf_putfiles(p, target, fp);
 1279 
 1280         /*
 1281          * Align up to a page boundary for the program segments.  The
 1282          * actual data will be written to the outptu file, not to elf_buf_t,
 1283          * so we do not have to do any further bounds checking.
 1284          */
 1285         target->off = round_page(target->off);
 1286         if (error == 0 && ehdr != NULL) {
 1287                 /*
 1288                  * Fill in the ELF header.
 1289                  */
 1290                 ehdr->e_ident[EI_MAG0] = ELFMAG0;
 1291                 ehdr->e_ident[EI_MAG1] = ELFMAG1;
 1292                 ehdr->e_ident[EI_MAG2] = ELFMAG2;
 1293                 ehdr->e_ident[EI_MAG3] = ELFMAG3;
 1294                 ehdr->e_ident[EI_CLASS] = ELF_CLASS;
 1295                 ehdr->e_ident[EI_DATA] = ELF_DATA;
 1296                 ehdr->e_ident[EI_VERSION] = EV_CURRENT;
 1297                 ehdr->e_ident[EI_OSABI] = ELFOSABI_FREEBSD;
 1298                 ehdr->e_ident[EI_ABIVERSION] = 0;
 1299                 ehdr->e_ident[EI_PAD] = 0;
 1300                 ehdr->e_type = ET_CORE;
 1301                 ehdr->e_machine = ELF_ARCH;
 1302                 ehdr->e_version = EV_CURRENT;
 1303                 ehdr->e_entry = 0;
 1304                 ehdr->e_phoff = phoff;
 1305                 ehdr->e_flags = 0;
 1306                 ehdr->e_ehsize = sizeof(Elf_Ehdr);
 1307                 ehdr->e_phentsize = sizeof(Elf_Phdr);
 1308                 ehdr->e_phnum = numsegs + 1;
 1309                 ehdr->e_shentsize = sizeof(Elf_Shdr);
 1310                 ehdr->e_shnum = 0;
 1311                 ehdr->e_shstrndx = SHN_UNDEF;
 1312         }
 1313         if (error == 0 && phdr != NULL) {
 1314                 /*
 1315                  * Fill in the program header entries.
 1316                  */
 1317                 struct phdr_closure phc;
 1318 
 1319                 /* The note segement. */
 1320                 phdr->p_type = PT_NOTE;
 1321                 phdr->p_offset = noteoff;
 1322                 phdr->p_vaddr = 0;
 1323                 phdr->p_paddr = 0;
 1324                 phdr->p_filesz = notesz;
 1325                 phdr->p_memsz = 0;
 1326                 phdr->p_flags = 0;
 1327                 phdr->p_align = 0;
 1328                 ++phdr;
 1329 
 1330                 /* All the writable segments from the program. */
 1331                 phc.phdr = phdr;
 1332                 phc.phdr_max = phdr + numsegs;
 1333                 phc.offset = target->off;
 1334                 each_segment(p, cb_put_phdr, &phc, 1);
 1335         }
 1336         return (error);
 1337 }
 1338 
 1339 /*
 1340  * Append core dump notes to target ELF buffer or simply update target size
 1341  * if dryrun selected.
 1342  */
 1343 static int
 1344 elf_putallnotes(struct lwp *corelp, elf_buf_t target, int sig,
 1345     enum putmode mode)
 1346 {
 1347         struct proc *p = corelp->lwp_proc;
 1348         int error;
 1349         struct {
 1350                 prstatus_t status;
 1351                 prfpregset_t fpregs;
 1352                 prpsinfo_t psinfo;
 1353         } *tmpdata;
 1354         prstatus_t *status;
 1355         prfpregset_t *fpregs;
 1356         prpsinfo_t *psinfo;
 1357         struct lwp *lp;
 1358 
 1359         /*
 1360          * Allocate temporary storage for notes on heap to avoid stack overflow.
 1361          */
 1362         if (mode != DRYRUN) {
 1363                 tmpdata = kmalloc(sizeof(*tmpdata), M_TEMP, M_ZERO | M_WAITOK);
 1364                 status = &tmpdata->status;
 1365                 fpregs = &tmpdata->fpregs;
 1366                 psinfo = &tmpdata->psinfo;
 1367         } else {
 1368                 tmpdata = NULL;
 1369                 status = NULL;
 1370                 fpregs = NULL;
 1371                 psinfo = NULL;
 1372         }
 1373 
 1374         /*
 1375          * Append LWP-agnostic note.
 1376          */
 1377         if (mode != DRYRUN) {
 1378                 psinfo->pr_version = PRPSINFO_VERSION;
 1379                 psinfo->pr_psinfosz = sizeof(prpsinfo_t);
 1380                 strncpy(psinfo->pr_fname, p->p_comm,
 1381                         sizeof(psinfo->pr_fname) - 1);
 1382                 /*
 1383                  * XXX - We don't fill in the command line arguments
 1384                  * properly yet.
 1385                  */
 1386                 strncpy(psinfo->pr_psargs, p->p_comm, PRARGSZ);
 1387         }
 1388         error =
 1389             elf_putnote(target, "FreeBSD", NT_PRPSINFO, psinfo, sizeof *psinfo);
 1390         if (error)
 1391                 goto exit;
 1392 
 1393         /*
 1394          * Append first note for LWP that triggered core so that it is
 1395          * the selected one when the debugger starts.
 1396          */
 1397         if (mode != DRYRUN) {
 1398                 status->pr_version = PRSTATUS_VERSION;
 1399                 status->pr_statussz = sizeof(prstatus_t);
 1400                 status->pr_gregsetsz = sizeof(gregset_t);
 1401                 status->pr_fpregsetsz = sizeof(fpregset_t);
 1402                 status->pr_osreldate = osreldate;
 1403                 status->pr_cursig = sig;
 1404                 /*
 1405                  * XXX GDB needs unique pr_pid for each LWP and does not
 1406                  * not support pr_pid==0 but lwp_tid can be 0, so hack unique
 1407                  * value.
 1408                  */
 1409                 status->pr_pid = p->p_pid + corelp->lwp_tid;
 1410                 fill_regs(corelp, &status->pr_reg);
 1411                 fill_fpregs(corelp, fpregs);
 1412         }
 1413         error =
 1414             elf_putnote(target, "FreeBSD", NT_PRSTATUS, status, sizeof *status);
 1415         if (error)
 1416                 goto exit;
 1417         error =
 1418             elf_putnote(target, "FreeBSD", NT_FPREGSET, fpregs, sizeof *fpregs);
 1419         if (error)
 1420                 goto exit;
 1421 
 1422         /*
 1423          * Then append notes for other LWPs.
 1424          */
 1425         FOREACH_LWP_IN_PROC(lp, p) {
 1426                 if (lp == corelp)
 1427                         continue;
 1428                 /* skip lwps being created */
 1429                 if (lp->lwp_thread == NULL)
 1430                         continue;
 1431                 if (mode != DRYRUN) {
 1432                         status->pr_pid = p->p_pid + lp->lwp_tid;
 1433                         fill_regs(lp, &status->pr_reg);
 1434                         fill_fpregs(lp, fpregs);
 1435                 }
 1436                 error = elf_putnote(target, "FreeBSD", NT_PRSTATUS,
 1437                                         status, sizeof *status);
 1438                 if (error)
 1439                         goto exit;
 1440                 error = elf_putnote(target, "FreeBSD", NT_FPREGSET,
 1441                                         fpregs, sizeof *fpregs);
 1442                 if (error)
 1443                         goto exit;
 1444         }
 1445 
 1446 exit:
 1447         if (tmpdata != NULL)
 1448                 kfree(tmpdata, M_TEMP);
 1449         return (error);
 1450 }
 1451 
 1452 static int
 1453 elf_putnote(elf_buf_t target, const char *name, int type,
 1454             const void *desc, size_t descsz)
 1455 {
 1456         int error = 0;
 1457         char *dst;
 1458         Elf_Note note;
 1459 
 1460         note.n_namesz = strlen(name) + 1;
 1461         note.n_descsz = descsz;
 1462         note.n_type = type;
 1463         dst = target_reserve(target, sizeof(note), &error);
 1464         if (dst != NULL)
 1465                 bcopy(&note, dst, sizeof note);
 1466         dst = target_reserve(target, note.n_namesz, &error);
 1467         if (dst != NULL)
 1468                 bcopy(name, dst, note.n_namesz);
 1469         target->off = roundup2(target->off, sizeof(Elf_Size));
 1470         dst = target_reserve(target, note.n_descsz, &error);
 1471         if (dst != NULL)
 1472                 bcopy(desc, dst, note.n_descsz);
 1473         target->off = roundup2(target->off, sizeof(Elf_Size));
 1474         return(error);
 1475 }
 1476 
 1477 
 1478 static int
 1479 elf_putsigs(struct lwp *lp, elf_buf_t target)
 1480 {
 1481         /* XXX lwp handle more than one lwp */
 1482         struct proc *p = lp->lwp_proc;
 1483         int error = 0;
 1484         struct ckpt_siginfo *csi;
 1485 
 1486         csi = target_reserve(target, sizeof(struct ckpt_siginfo), &error);
 1487         if (csi) {
 1488                 csi->csi_ckptpisz = sizeof(struct ckpt_siginfo);
 1489                 bcopy(p->p_sigacts, &csi->csi_sigacts, sizeof(*p->p_sigacts));
 1490                 bcopy(&p->p_realtimer, &csi->csi_itimerval, sizeof(struct itimerval));
 1491                 bcopy(&lp->lwp_sigmask, &csi->csi_sigmask,
 1492                         sizeof(sigset_t));
 1493                 csi->csi_sigparent = p->p_sigparent;
 1494         }
 1495         return(error);
 1496 }
 1497 
 1498 static int
 1499 elf_putfiles(struct proc *p, elf_buf_t target, struct file *ckfp)
 1500 {
 1501         int error = 0;
 1502         int i;
 1503         struct ckpt_filehdr *cfh = NULL;
 1504         struct ckpt_fileinfo *cfi;
 1505         struct file *fp;        
 1506         struct vnode *vp;
 1507         /*
 1508          * the duplicated loop is gross, but it was the only way
 1509          * to eliminate uninitialized variable warnings 
 1510          */
 1511         cfh = target_reserve(target, sizeof(struct ckpt_filehdr), &error);
 1512         if (cfh) {
 1513                 cfh->cfh_nfiles = 0;            
 1514         }
 1515 
 1516         /*
 1517          * ignore STDIN/STDERR/STDOUT.
 1518          */
 1519         for (i = 3; error == 0 && i < p->p_fd->fd_nfiles; i++) {
 1520                 fp = holdfp(p->p_fd, i, -1);
 1521                 if (fp == NULL)
 1522                         continue;
 1523                 /* 
 1524                  * XXX Only checkpoint vnodes for now.
 1525                  */
 1526                 if (fp->f_type != DTYPE_VNODE) {
 1527                         fdrop(fp);
 1528                         continue;
 1529                 }
 1530                 cfi = target_reserve(target, sizeof(struct ckpt_fileinfo),
 1531                                         &error);
 1532                 if (cfi == NULL) {
 1533                         fdrop(fp);
 1534                         continue;
 1535                 }
 1536                 cfi->cfi_index = -1;
 1537                 cfi->cfi_type = fp->f_type;
 1538                 cfi->cfi_flags = fp->f_flag;
 1539                 cfi->cfi_offset = fp->f_offset;
 1540                 cfi->cfi_ckflags = 0;
 1541 
 1542                 if (fp == ckfp)
 1543                         cfi->cfi_ckflags |= CKFIF_ISCKPTFD;
 1544                 /* f_count and f_msgcount should not be saved/restored */
 1545                 /* XXX save cred info */
 1546 
 1547                 switch(fp->f_type) {
 1548                 case DTYPE_VNODE:
 1549                         vp = (struct vnode *)fp->f_data;
 1550                         /*
 1551                          * it looks like a bug in ptrace is marking 
 1552                          * a non-vnode as a vnode - until we find the 
 1553                          * root cause this will at least prevent
 1554                          * further panics from truss
 1555                          */
 1556                         if (vp == NULL || vp->v_mount == NULL)
 1557                                 break;
 1558                         cfh->cfh_nfiles++;
 1559                         cfi->cfi_index = i;
 1560                         cfi->cfi_fh.fh_fsid = vp->v_mount->mnt_stat.f_fsid;
 1561                         error = VFS_VPTOFH(vp, &cfi->cfi_fh.fh_fid);
 1562                         break;
 1563                 default:
 1564                         break;
 1565                 }
 1566                 fdrop(fp);
 1567         }
 1568         return(error);
 1569 }
 1570 
 1571 static int
 1572 elf_puttextvp(struct proc *p, elf_buf_t target)
 1573 {
 1574         int error = 0;
 1575         int *vn_count;
 1576         struct fp_closure fpc;
 1577         struct ckpt_vminfo *vminfo;
 1578 
 1579         vminfo = target_reserve(target, sizeof(struct ckpt_vminfo), &error);
 1580         if (vminfo != NULL) {
 1581                 vminfo->cvm_dsize = p->p_vmspace->vm_dsize;
 1582                 vminfo->cvm_tsize = p->p_vmspace->vm_tsize;
 1583                 vminfo->cvm_daddr = p->p_vmspace->vm_daddr;
 1584                 vminfo->cvm_taddr = p->p_vmspace->vm_taddr;
 1585         }
 1586 
 1587         fpc.count = 0;
 1588         vn_count = target_reserve(target, sizeof(int), &error);
 1589         if (target->buf != NULL) {
 1590                 fpc.vnh = (struct vn_hdr *)(target->buf + target->off);
 1591                 fpc.vnh_max = fpc.vnh + 
 1592                         (target->off_max - target->off) / sizeof(struct vn_hdr);
 1593                 error = each_segment(p, cb_put_fp, &fpc, 0);
 1594                 if (vn_count)
 1595                         *vn_count = fpc.count;
 1596         } else {
 1597                 error = each_segment(p, cb_fpcount_segment, &fpc.count, 0);
 1598         }
 1599         target->off += fpc.count * sizeof(struct vn_hdr);
 1600         return(error);
 1601 }
 1602 
 1603 
 1604 /*
 1605  * Tell kern_execve.c about it, with a little help from the linker.
 1606  */
 1607 static struct execsw elf_execsw = {exec_elf_imgact, "ELF"};
 1608 EXEC_SET_ORDERED(elf, elf_execsw, SI_ORDER_FIRST);

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