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


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

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

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

    1 /*-
    2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
    3  *
    4  * Copyright (c) 1993, David Greenman
    5  * All rights reserved.
    6  *
    7  * Redistribution and use in source and binary forms, with or without
    8  * modification, are permitted provided that the following conditions
    9  * are met:
   10  * 1. Redistributions of source code must retain the above copyright
   11  *    notice, this list of conditions and the following disclaimer.
   12  * 2. Redistributions in binary form must reproduce the above copyright
   13  *    notice, this list of conditions and the following disclaimer in the
   14  *    documentation and/or other materials provided with the distribution.
   15  *
   16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
   17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
   20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   26  * SUCH DAMAGE.
   27  */
   28 
   29 #include <sys/cdefs.h>
   30 __FBSDID("$FreeBSD$");
   31 
   32 #include <sys/param.h>
   33 #include <sys/exec.h>
   34 #include <sys/imgact.h>
   35 #include <sys/imgact_aout.h>
   36 #include <sys/kernel.h>
   37 #include <sys/limits.h>
   38 #include <sys/lock.h>
   39 #include <sys/malloc.h>
   40 #include <sys/mutex.h>
   41 #include <sys/proc.h>
   42 #include <sys/racct.h>
   43 #include <sys/resourcevar.h>
   44 #include <sys/signalvar.h>
   45 #include <sys/syscall.h>
   46 #include <sys/sysent.h>
   47 #include <sys/systm.h>
   48 #include <sys/vnode.h>
   49 
   50 #include <machine/frame.h>
   51 #include <machine/md_var.h>
   52 
   53 #include <vm/vm.h>
   54 #include <vm/pmap.h>
   55 #include <vm/vm_map.h>
   56 #include <vm/vm_object.h>
   57 #include <vm/vm_param.h>
   58 
   59 #ifdef __amd64__
   60 #include <compat/freebsd32/freebsd32_signal.h>
   61 #include <compat/freebsd32/freebsd32_util.h>
   62 #include <compat/freebsd32/freebsd32_proto.h>
   63 #include <compat/freebsd32/freebsd32_syscall.h>
   64 #include <compat/ia32/ia32_signal.h>
   65 #endif
   66 
   67 static int      exec_aout_imgact(struct image_params *imgp);
   68 static int      aout_fixup(uintptr_t *stack_base, struct image_params *imgp);
   69 
   70 #define AOUT32_USRSTACK         0xbfc00000
   71 
   72 #if defined(__i386__)
   73 
   74 #define AOUT32_PS_STRINGS       (AOUT32_USRSTACK - sizeof(struct ps_strings))
   75 
   76 struct sysentvec aout_sysvec = {
   77         .sv_size        = SYS_MAXSYSCALL,
   78         .sv_table       = sysent,
   79         .sv_fixup       = aout_fixup,
   80         .sv_sendsig     = sendsig,
   81         .sv_sigcode     = sigcode,
   82         .sv_szsigcode   = &szsigcode,
   83         .sv_name        = "FreeBSD a.out",
   84         .sv_coredump    = NULL,
   85         .sv_imgact_try  = NULL,
   86         .sv_minsigstksz = MINSIGSTKSZ,
   87         .sv_minuser     = VM_MIN_ADDRESS,
   88         .sv_maxuser     = AOUT32_USRSTACK,
   89         .sv_usrstack    = AOUT32_USRSTACK,
   90         .sv_psstrings   = AOUT32_PS_STRINGS,
   91         .sv_psstringssz = sizeof(struct ps_strings),
   92         .sv_stackprot   = VM_PROT_ALL,
   93         .sv_copyout_strings     = exec_copyout_strings,
   94         .sv_setregs     = exec_setregs,
   95         .sv_fixlimit    = NULL,
   96         .sv_maxssiz     = NULL,
   97         .sv_flags       = SV_ABI_FREEBSD | SV_AOUT | SV_IA32 | SV_ILP32,
   98         .sv_set_syscall_retval = cpu_set_syscall_retval,
   99         .sv_fetch_syscall_args = cpu_fetch_syscall_args,
  100         .sv_syscallnames = syscallnames,
  101         .sv_schedtail   = NULL,
  102         .sv_thread_detach = NULL,
  103         .sv_trap        = NULL,
  104         .sv_onexec_old = exec_onexec_old,
  105         .sv_onexit =  exit_onexit,
  106         .sv_set_fork_retval = x86_set_fork_retval,
  107 };
  108 
  109 #elif defined(__amd64__)
  110 
  111 #include "vdso_ia32_offsets.h"
  112 
  113 extern const char _binary_elf_vdso32_so_1_start[];
  114 extern const char _binary_elf_vdso32_so_1_end[];
  115 extern char _binary_elf_vdso32_so_1_size;
  116 
  117 #define AOUT32_PS_STRINGS \
  118     (AOUT32_USRSTACK - sizeof(struct freebsd32_ps_strings))
  119 #define AOUT32_MINUSER          FREEBSD32_MINUSER
  120 
  121 extern const char *freebsd32_syscallnames[];
  122 extern u_long ia32_maxssiz;
  123 
  124 static int aout_szsigcode;
  125 
  126 struct sysentvec aout_sysvec = {
  127         .sv_size        = FREEBSD32_SYS_MAXSYSCALL,
  128         .sv_table       = freebsd32_sysent,
  129         .sv_fixup       = aout_fixup,
  130         .sv_sendsig     = ia32_sendsig,
  131         .sv_sigcode     = _binary_elf_vdso32_so_1_start,
  132         .sv_szsigcode   = &aout_szsigcode,
  133         .sv_name        = "FreeBSD a.out",
  134         .sv_coredump    = NULL,
  135         .sv_imgact_try  = NULL,
  136         .sv_minsigstksz = MINSIGSTKSZ,
  137         .sv_minuser     = AOUT32_MINUSER,
  138         .sv_maxuser     = AOUT32_USRSTACK,
  139         .sv_usrstack    = AOUT32_USRSTACK,
  140         .sv_psstrings   = AOUT32_PS_STRINGS,
  141         .sv_psstringssz = sizeof(struct freebsd32_ps_strings),
  142         .sv_stackprot   = VM_PROT_ALL,
  143         .sv_copyout_strings     = freebsd32_copyout_strings,
  144         .sv_setregs     = ia32_setregs,
  145         .sv_fixlimit    = ia32_fixlimit,
  146         .sv_maxssiz     = &ia32_maxssiz,
  147         .sv_flags       = SV_ABI_FREEBSD | SV_AOUT | SV_IA32 | SV_ILP32,
  148         .sv_set_syscall_retval = ia32_set_syscall_retval,
  149         .sv_fetch_syscall_args = ia32_fetch_syscall_args,
  150         .sv_syscallnames = freebsd32_syscallnames,
  151         .sv_onexec_old  = exec_onexec_old,
  152         .sv_onexit      = exit_onexit,
  153         .sv_set_fork_retval = x86_set_fork_retval,
  154 };
  155 
  156 static void
  157 aout_sysent(void *arg __unused)
  158 {
  159         aout_szsigcode = (int)(uintptr_t)&_binary_elf_vdso32_so_1_size;
  160 }
  161 SYSINIT(aout_sysent, SI_SUB_EXEC, SI_ORDER_ANY, aout_sysent, NULL);
  162 #else
  163 #error "Only ia32 arch is supported"
  164 #endif
  165 
  166 static int
  167 aout_fixup(uintptr_t *stack_base, struct image_params *imgp)
  168 {
  169 
  170         *stack_base -= sizeof(uint32_t);
  171         if (suword32((void *)*stack_base, imgp->args->argc) != 0)
  172                 return (EFAULT);
  173         return (0);
  174 }
  175 
  176 static int
  177 exec_aout_imgact(struct image_params *imgp)
  178 {
  179         const struct exec *a_out;
  180         struct vmspace *vmspace;
  181         vm_map_t map;
  182         vm_object_t object;
  183         vm_offset_t text_end, data_end;
  184         unsigned long virtual_offset;
  185         unsigned long file_offset;
  186         unsigned long bss_size;
  187         int error;
  188 
  189         a_out = (const struct exec *)imgp->image_header;
  190 
  191         /*
  192          * Linux and *BSD binaries look very much alike,
  193          * only the machine id is different:
  194          * 0x64 for Linux, 0x86 for *BSD, 0x00 for BSDI.
  195          * NetBSD is in network byte order.. ugh.
  196          */
  197         if (((a_out->a_midmag >> 16) & 0xff) != 0x86 &&
  198             ((a_out->a_midmag >> 16) & 0xff) != 0 &&
  199             ((((int)ntohl(a_out->a_midmag)) >> 16) & 0xff) != 0x86)
  200                 return (-1);
  201 
  202         /*
  203          * Set file/virtual offset based on a.out variant.
  204          *      We do two cases: host byte order and network byte order
  205          *      (for NetBSD compatibility)
  206          */
  207         switch ((int)(a_out->a_midmag & 0xffff)) {
  208         case ZMAGIC:
  209                 virtual_offset = 0;
  210                 if (a_out->a_text) {
  211                         file_offset = PAGE_SIZE;
  212                 } else {
  213                         /* Bill's "screwball mode" */
  214                         file_offset = 0;
  215                 }
  216                 break;
  217         case QMAGIC:
  218                 virtual_offset = PAGE_SIZE;
  219                 file_offset = 0;
  220                 /* Pass PS_STRINGS for BSD/OS binaries only. */
  221                 if (N_GETMID(*a_out) == MID_ZERO)
  222                         imgp->ps_strings = (void *)aout_sysvec.sv_psstrings;
  223                 break;
  224         default:
  225                 /* NetBSD compatibility */
  226                 switch ((int)(ntohl(a_out->a_midmag) & 0xffff)) {
  227                 case ZMAGIC:
  228                 case QMAGIC:
  229                         virtual_offset = PAGE_SIZE;
  230                         file_offset = 0;
  231                         break;
  232                 default:
  233                         return (-1);
  234                 }
  235         }
  236 
  237         bss_size = roundup(a_out->a_bss, PAGE_SIZE);
  238 
  239         /*
  240          * Check various fields in header for validity/bounds.
  241          */
  242         if (/* entry point must lay with text region */
  243             a_out->a_entry < virtual_offset ||
  244             a_out->a_entry >= virtual_offset + a_out->a_text ||
  245 
  246             /* text and data size must each be page rounded */
  247             a_out->a_text & PAGE_MASK || a_out->a_data & PAGE_MASK
  248 
  249 #ifdef __amd64__
  250             ||
  251             /* overflows */
  252             virtual_offset + a_out->a_text + a_out->a_data + bss_size > UINT_MAX
  253 #endif
  254             )
  255                 return (-1);
  256 
  257         /* text + data can't exceed file size */
  258         if (a_out->a_data + a_out->a_text > imgp->attr->va_size)
  259                 return (EFAULT);
  260 
  261         /*
  262          * text/data/bss must not exceed limits
  263          */
  264         PROC_LOCK(imgp->proc);
  265         if (/* text can't exceed maximum text size */
  266             a_out->a_text > maxtsiz ||
  267 
  268             /* data + bss can't exceed rlimit */
  269             a_out->a_data + bss_size > lim_cur_proc(imgp->proc, RLIMIT_DATA) ||
  270             racct_set(imgp->proc, RACCT_DATA, a_out->a_data + bss_size) != 0) {
  271                 PROC_UNLOCK(imgp->proc);
  272                 return (ENOMEM);
  273         }
  274         PROC_UNLOCK(imgp->proc);
  275 
  276         /*
  277          * Avoid a possible deadlock if the current address space is destroyed
  278          * and that address space maps the locked vnode.  In the common case,
  279          * the locked vnode's v_usecount is decremented but remains greater
  280          * than zero.  Consequently, the vnode lock is not needed by vrele().
  281          * However, in cases where the vnode lock is external, such as nullfs,
  282          * v_usecount may become zero.
  283          */
  284         VOP_UNLOCK(imgp->vp);
  285 
  286         /*
  287          * Destroy old process VM and create a new one (with a new stack)
  288          */
  289         error = exec_new_vmspace(imgp, &aout_sysvec);
  290 
  291         vn_lock(imgp->vp, LK_SHARED | LK_RETRY);
  292         if (error)
  293                 return (error);
  294 
  295         /*
  296          * The vm space can be changed by exec_new_vmspace
  297          */
  298         vmspace = imgp->proc->p_vmspace;
  299 
  300         object = imgp->object;
  301         map = &vmspace->vm_map;
  302         vm_map_lock(map);
  303         vm_object_reference(object);
  304 
  305         text_end = virtual_offset + a_out->a_text;
  306         error = vm_map_insert(map, object,
  307                 file_offset,
  308                 virtual_offset, text_end,
  309                 VM_PROT_READ | VM_PROT_EXECUTE, VM_PROT_ALL,
  310                 MAP_COPY_ON_WRITE | MAP_PREFAULT | MAP_VN_EXEC);
  311         if (error) {
  312                 vm_map_unlock(map);
  313                 vm_object_deallocate(object);
  314                 return (error);
  315         }
  316         VOP_SET_TEXT_CHECKED(imgp->vp);
  317         data_end = text_end + a_out->a_data;
  318         if (a_out->a_data) {
  319                 vm_object_reference(object);
  320                 error = vm_map_insert(map, object,
  321                         file_offset + a_out->a_text,
  322                         text_end, data_end,
  323                         VM_PROT_ALL, VM_PROT_ALL,
  324                         MAP_COPY_ON_WRITE | MAP_PREFAULT | MAP_VN_EXEC);
  325                 if (error) {
  326                         vm_map_unlock(map);
  327                         vm_object_deallocate(object);
  328                         return (error);
  329                 }
  330                 VOP_SET_TEXT_CHECKED(imgp->vp);
  331         }
  332 
  333         if (bss_size) {
  334                 error = vm_map_insert(map, NULL, 0,
  335                         data_end, data_end + bss_size,
  336                         VM_PROT_ALL, VM_PROT_ALL, 0);
  337                 if (error) {
  338                         vm_map_unlock(map);
  339                         return (error);
  340                 }
  341         }
  342         vm_map_unlock(map);
  343 
  344         /* Fill in process VM information */
  345         vmspace->vm_tsize = a_out->a_text >> PAGE_SHIFT;
  346         vmspace->vm_dsize = (a_out->a_data + bss_size) >> PAGE_SHIFT;
  347         vmspace->vm_taddr = (caddr_t) (uintptr_t) virtual_offset;
  348         vmspace->vm_daddr = (caddr_t) (uintptr_t)
  349                             (virtual_offset + a_out->a_text);
  350 
  351         error = exec_map_stack(imgp);
  352         if (error != 0)
  353                 return (error);
  354 
  355         /* Fill in image_params */
  356         imgp->interpreted = 0;
  357         imgp->entry_addr = a_out->a_entry;
  358 
  359         imgp->proc->p_sysent = &aout_sysvec;
  360 
  361         return (0);
  362 }
  363 
  364 /*
  365  * Tell kern_execve.c about it, with a little help from the linker.
  366  */
  367 static struct execsw aout_execsw = {
  368         .ex_imgact = exec_aout_imgact,
  369         .ex_name = "a.out"
  370 };
  371 EXEC_SET(aout, aout_execsw);

Cache object: 7e8dfc948e83fa8a64893e84f663b6e7


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


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