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/kern_exec.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  * Copyright (c) 1993, David Greenman
    3  * All rights reserved.
    4  *
    5  * Redistribution and use in source and binary forms, with or without
    6  * modification, are permitted provided that the following conditions
    7  * are met:
    8  * 1. Redistributions of source code must retain the above copyright
    9  *    notice, this list of conditions and the following disclaimer.
   10  * 2. Redistributions in binary form must reproduce the above copyright
   11  *    notice, this list of conditions and the following disclaimer in the
   12  *    documentation and/or other materials provided with the distribution.
   13  *
   14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
   15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
   18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   24  * SUCH DAMAGE.
   25  */
   26 
   27 #include <sys/cdefs.h>
   28 __FBSDID("$FreeBSD: releng/6.0/sys/kern/kern_exec.c 151173 2005-10-09 17:28:12Z ps $");
   29 
   30 #include "opt_hwpmc_hooks.h"
   31 #include "opt_ktrace.h"
   32 #include "opt_mac.h"
   33 
   34 #include <sys/param.h>
   35 #include <sys/systm.h>
   36 #include <sys/eventhandler.h>
   37 #include <sys/lock.h>
   38 #include <sys/mutex.h>
   39 #include <sys/sysproto.h>
   40 #include <sys/signalvar.h>
   41 #include <sys/kernel.h>
   42 #include <sys/mac.h>
   43 #include <sys/mount.h>
   44 #include <sys/filedesc.h>
   45 #include <sys/fcntl.h>
   46 #include <sys/acct.h>
   47 #include <sys/exec.h>
   48 #include <sys/imgact.h>
   49 #include <sys/imgact_elf.h>
   50 #include <sys/wait.h>
   51 #include <sys/malloc.h>
   52 #include <sys/proc.h>
   53 #include <sys/pioctl.h>
   54 #include <sys/namei.h>
   55 #include <sys/resourcevar.h>
   56 #include <sys/sf_buf.h>
   57 #include <sys/syscallsubr.h>
   58 #include <sys/sysent.h>
   59 #include <sys/shm.h>
   60 #include <sys/sysctl.h>
   61 #include <sys/vnode.h>
   62 #ifdef KTRACE
   63 #include <sys/ktrace.h>
   64 #endif
   65 
   66 #include <vm/vm.h>
   67 #include <vm/vm_param.h>
   68 #include <vm/pmap.h>
   69 #include <vm/vm_page.h>
   70 #include <vm/vm_map.h>
   71 #include <vm/vm_kern.h>
   72 #include <vm/vm_extern.h>
   73 #include <vm/vm_object.h>
   74 #include <vm/vm_pager.h>
   75 
   76 #ifdef  HWPMC_HOOKS
   77 #include <sys/pmckern.h>
   78 #endif
   79 
   80 #include <machine/reg.h>
   81 
   82 MALLOC_DEFINE(M_PARGS, "proc-args", "Process arguments");
   83 
   84 static int sysctl_kern_ps_strings(SYSCTL_HANDLER_ARGS);
   85 static int sysctl_kern_usrstack(SYSCTL_HANDLER_ARGS);
   86 static int sysctl_kern_stackprot(SYSCTL_HANDLER_ARGS);
   87 static int do_execve(struct thread *td, struct image_args *args,
   88     struct mac *mac_p);
   89 
   90 /* XXX This should be vm_size_t. */
   91 SYSCTL_PROC(_kern, KERN_PS_STRINGS, ps_strings, CTLTYPE_ULONG|CTLFLAG_RD,
   92     NULL, 0, sysctl_kern_ps_strings, "LU", "");
   93 
   94 /* XXX This should be vm_size_t. */
   95 SYSCTL_PROC(_kern, KERN_USRSTACK, usrstack, CTLTYPE_ULONG|CTLFLAG_RD,
   96     NULL, 0, sysctl_kern_usrstack, "LU", "");
   97 
   98 SYSCTL_PROC(_kern, OID_AUTO, stackprot, CTLTYPE_INT|CTLFLAG_RD,
   99     NULL, 0, sysctl_kern_stackprot, "I", "");
  100 
  101 u_long ps_arg_cache_limit = PAGE_SIZE / 16;
  102 SYSCTL_ULONG(_kern, OID_AUTO, ps_arg_cache_limit, CTLFLAG_RW, 
  103     &ps_arg_cache_limit, 0, "");
  104 
  105 static int
  106 sysctl_kern_ps_strings(SYSCTL_HANDLER_ARGS)
  107 {
  108         struct proc *p;
  109         int error;
  110 
  111         p = curproc;
  112 #ifdef SCTL_MASK32
  113         if (req->flags & SCTL_MASK32) {
  114                 unsigned int val;
  115                 val = (unsigned int)p->p_sysent->sv_psstrings;
  116                 error = SYSCTL_OUT(req, &val, sizeof(val));
  117         } else
  118 #endif
  119                 error = SYSCTL_OUT(req, &p->p_sysent->sv_psstrings,
  120                    sizeof(p->p_sysent->sv_psstrings));
  121         return error;
  122 }
  123 
  124 static int
  125 sysctl_kern_usrstack(SYSCTL_HANDLER_ARGS)
  126 {
  127         struct proc *p;
  128         int error;
  129 
  130         p = curproc;
  131 #ifdef SCTL_MASK32
  132         if (req->flags & SCTL_MASK32) {
  133                 unsigned int val;
  134                 val = (unsigned int)p->p_sysent->sv_usrstack;
  135                 error = SYSCTL_OUT(req, &val, sizeof(val));
  136         } else
  137 #endif
  138                 error = SYSCTL_OUT(req, &p->p_sysent->sv_usrstack,
  139                     sizeof(p->p_sysent->sv_usrstack));
  140         return error;
  141 }
  142 
  143 static int
  144 sysctl_kern_stackprot(SYSCTL_HANDLER_ARGS)
  145 {
  146         struct proc *p;
  147 
  148         p = curproc;
  149         return (SYSCTL_OUT(req, &p->p_sysent->sv_stackprot,
  150             sizeof(p->p_sysent->sv_stackprot)));
  151 }
  152 
  153 /*
  154  * Each of the items is a pointer to a `const struct execsw', hence the
  155  * double pointer here.
  156  */
  157 static const struct execsw **execsw;
  158 
  159 #ifndef _SYS_SYSPROTO_H_
  160 struct execve_args {
  161         char    *fname; 
  162         char    **argv;
  163         char    **envv; 
  164 };
  165 #endif
  166 
  167 /*
  168  * MPSAFE
  169  */
  170 int
  171 execve(td, uap)
  172         struct thread *td;
  173         struct execve_args /* {
  174                 char *fname;
  175                 char **argv;
  176                 char **envv;
  177         } */ *uap;
  178 {
  179         int error;
  180         struct image_args args;
  181 
  182         error = exec_copyin_args(&args, uap->fname, UIO_USERSPACE,
  183             uap->argv, uap->envv);
  184 
  185         if (error == 0)
  186                 error = kern_execve(td, &args, NULL);
  187 
  188         exec_free_args(&args);
  189 
  190         return (error);
  191 }
  192 
  193 #ifndef _SYS_SYSPROTO_H_
  194 struct __mac_execve_args {
  195         char    *fname;
  196         char    **argv;
  197         char    **envv;
  198         struct mac      *mac_p;
  199 };
  200 #endif
  201 
  202 /*
  203  * MPSAFE
  204  */
  205 int
  206 __mac_execve(td, uap)
  207         struct thread *td;
  208         struct __mac_execve_args /* {
  209                 char *fname;
  210                 char **argv;
  211                 char **envv;
  212                 struct mac *mac_p;
  213         } */ *uap;
  214 {
  215 #ifdef MAC
  216         int error;
  217         struct image_args args;
  218 
  219         error = exec_copyin_args(&args, uap->fname, UIO_USERSPACE,
  220             uap->argv, uap->envv);
  221 
  222         if (error == 0)
  223                 error = kern_execve(td, &args, uap->mac_p);
  224 
  225         exec_free_args(&args);
  226 
  227         return (error);
  228 #else
  229         return (ENOSYS);
  230 #endif
  231 }
  232 
  233 /*
  234  * XXX: kern_execve has the astonishing property of not always
  235  * returning to the caller.  If sufficiently bad things happen during
  236  * the call to do_execve(), it can end up calling exit1(); as a result,
  237  * callers must avoid doing anything which they might need to undo
  238  * (e.g., allocating memory).
  239  */
  240 int
  241 kern_execve(td, args, mac_p)
  242         struct thread *td;
  243         struct image_args *args;
  244         struct mac *mac_p;
  245 {
  246         struct proc *p = td->td_proc;
  247         int error;
  248 
  249         if (p->p_flag & P_HADTHREADS) {
  250                 PROC_LOCK(p);
  251                 if (thread_single(SINGLE_BOUNDARY)) {
  252                         PROC_UNLOCK(p);
  253                         return (ERESTART);      /* Try again later. */
  254                 }
  255                 PROC_UNLOCK(p);
  256         }
  257 
  258         error = do_execve(td, args, mac_p);
  259 
  260         if (p->p_flag & P_HADTHREADS) {
  261                 PROC_LOCK(p);
  262                 /*
  263                  * If success, we upgrade to SINGLE_EXIT state to
  264                  * force other threads to suicide.
  265                  */
  266                 if (error == 0)
  267                         thread_single(SINGLE_EXIT);
  268                 else
  269                         thread_single_end();
  270                 PROC_UNLOCK(p);
  271         }
  272 
  273         return (error);
  274 }
  275 
  276 /*
  277  * In-kernel implementation of execve().  All arguments are assumed to be
  278  * userspace pointers from the passed thread.
  279  *
  280  * MPSAFE
  281  */
  282 static int
  283 do_execve(td, args, mac_p)
  284         struct thread *td;
  285         struct image_args *args;
  286         struct mac *mac_p;
  287 {
  288         struct proc *p = td->td_proc;
  289         struct nameidata nd, *ndp;
  290         struct ucred *newcred = NULL, *oldcred;
  291         struct uidinfo *euip;
  292         register_t *stack_base;
  293         int error, len, i;
  294         struct image_params image_params, *imgp;
  295         struct vattr atimeattr, attr;
  296         int (*img_first)(struct image_params *);
  297         struct pargs *oldargs = NULL, *newargs = NULL;
  298         struct sigacts *oldsigacts, *newsigacts;
  299 #ifdef KTRACE
  300         struct vnode *tracevp = NULL;
  301         struct ucred *tracecred = NULL;
  302 #endif
  303         struct vnode *textvp = NULL;
  304         int credential_changing;
  305         int vfslocked;
  306         int textset;
  307 #ifdef MAC
  308         struct label *interplabel = NULL;
  309         int will_transition;
  310 #endif
  311 #ifdef HWPMC_HOOKS
  312         struct pmckern_procexec pe;
  313 #endif
  314 
  315         vfslocked = 0;
  316         imgp = &image_params;
  317 
  318         /*
  319          * Lock the process and set the P_INEXEC flag to indicate that
  320          * it should be left alone until we're done here.  This is
  321          * necessary to avoid race conditions - e.g. in ptrace() -
  322          * that might allow a local user to illicitly obtain elevated
  323          * privileges.
  324          */
  325         PROC_LOCK(p);
  326         KASSERT((p->p_flag & P_INEXEC) == 0,
  327             ("%s(): process already has P_INEXEC flag", __func__));
  328         p->p_flag |= P_INEXEC;
  329         PROC_UNLOCK(p);
  330 
  331         /*
  332          * Initialize part of the common data
  333          */
  334         imgp->proc = p;
  335         imgp->execlabel = NULL;
  336         imgp->attr = &attr;
  337         imgp->entry_addr = 0;
  338         imgp->vmspace_destroyed = 0;
  339         imgp->interpreted = 0;
  340         imgp->interpreter_name = args->buf + PATH_MAX + ARG_MAX;
  341         imgp->auxargs = NULL;
  342         imgp->vp = NULL;
  343         imgp->object = NULL;
  344         imgp->firstpage = NULL;
  345         imgp->ps_strings = 0;
  346         imgp->auxarg_size = 0;
  347         imgp->args = args;
  348 
  349 #ifdef MAC
  350         error = mac_execve_enter(imgp, mac_p);
  351         if (error)
  352                 goto exec_fail;
  353 #endif
  354 
  355         imgp->image_header = NULL;
  356 
  357         /*
  358          * Translate the file name. namei() returns a vnode pointer
  359          *      in ni_vp amoung other things.
  360          */
  361         ndp = &nd;
  362         NDINIT(ndp, LOOKUP, ISOPEN | LOCKLEAF | FOLLOW | SAVENAME | MPSAFE,
  363             UIO_SYSSPACE, args->fname, td);
  364 
  365 interpret:
  366         error = namei(ndp);
  367         if (error)
  368                 goto exec_fail;
  369 
  370         vfslocked = NDHASGIANT(ndp);
  371         imgp->vp = ndp->ni_vp;
  372 
  373         /*
  374          * Check file permissions (also 'opens' file)
  375          */
  376         error = exec_check_permissions(imgp);
  377         if (error)
  378                 goto exec_fail_dealloc;
  379 
  380         imgp->object = imgp->vp->v_object;
  381         if (imgp->object != NULL)
  382                 vm_object_reference(imgp->object);
  383 
  384         /*
  385          * Set VV_TEXT now so no one can write to the executable while we're
  386          * activating it.
  387          *
  388          * Remember if this was set before and unset it in case this is not
  389          * actually an executable image.
  390          */
  391         textset = imgp->vp->v_vflag & VV_TEXT;
  392         imgp->vp->v_vflag |= VV_TEXT;
  393 
  394         error = exec_map_first_page(imgp);
  395         if (error)
  396                 goto exec_fail_dealloc;
  397 
  398         /*
  399          *      If the current process has a special image activator it
  400          *      wants to try first, call it.   For example, emulating shell
  401          *      scripts differently.
  402          */
  403         error = -1;
  404         if ((img_first = imgp->proc->p_sysent->sv_imgact_try) != NULL)
  405                 error = img_first(imgp);
  406 
  407         /*
  408          *      Loop through the list of image activators, calling each one.
  409          *      An activator returns -1 if there is no match, 0 on success,
  410          *      and an error otherwise.
  411          */
  412         for (i = 0; error == -1 && execsw[i]; ++i) {
  413                 if (execsw[i]->ex_imgact == NULL ||
  414                     execsw[i]->ex_imgact == img_first) {
  415                         continue;
  416                 }
  417                 error = (*execsw[i]->ex_imgact)(imgp);
  418         }
  419 
  420         if (error) {
  421                 if (error == -1) {
  422                         if (textset == 0)
  423                                 imgp->vp->v_vflag &= ~VV_TEXT;
  424                         error = ENOEXEC;
  425                 }
  426                 goto exec_fail_dealloc;
  427         }
  428 
  429         /*
  430          * Special interpreter operation, cleanup and loop up to try to
  431          * activate the interpreter.
  432          */
  433         if (imgp->interpreted) {
  434                 exec_unmap_first_page(imgp);
  435                 /*
  436                  * VV_TEXT needs to be unset for scripts.  There is a short
  437                  * period before we determine that something is a script where
  438                  * VV_TEXT will be set. The vnode lock is held over this
  439                  * entire period so nothing should illegitimately be blocked.
  440                  */
  441                 imgp->vp->v_vflag &= ~VV_TEXT;
  442                 /* free name buffer and old vnode */
  443                 NDFREE(ndp, NDF_ONLY_PNBUF);
  444 #ifdef MAC
  445                 interplabel = mac_vnode_label_alloc();
  446                 mac_copy_vnode_label(ndp->ni_vp->v_label, interplabel);
  447 #endif
  448                 vput(ndp->ni_vp);
  449                 vm_object_deallocate(imgp->object);
  450                 imgp->object = NULL;
  451                 VFS_UNLOCK_GIANT(vfslocked);
  452                 vfslocked = 0;
  453                 /* set new name to that of the interpreter */
  454                 NDINIT(ndp, LOOKUP, LOCKLEAF | FOLLOW | SAVENAME | MPSAFE,
  455                     UIO_SYSSPACE, imgp->interpreter_name, td);
  456                 goto interpret;
  457         }
  458 
  459         /*
  460          * Copy out strings (args and env) and initialize stack base
  461          */
  462         if (p->p_sysent->sv_copyout_strings)
  463                 stack_base = (*p->p_sysent->sv_copyout_strings)(imgp);
  464         else
  465                 stack_base = exec_copyout_strings(imgp);
  466 
  467         /*
  468          * If custom stack fixup routine present for this process
  469          * let it do the stack setup.
  470          * Else stuff argument count as first item on stack
  471          */
  472         if (p->p_sysent->sv_fixup != NULL)
  473                 (*p->p_sysent->sv_fixup)(&stack_base, imgp);
  474         else
  475                 suword(--stack_base, imgp->args->argc);
  476 
  477         /*
  478          * For security and other reasons, the file descriptor table cannot
  479          * be shared after an exec.
  480          */
  481         fdunshare(p, td);
  482 
  483         /*
  484          * Malloc things before we need locks.
  485          */
  486         newcred = crget();
  487         euip = uifind(attr.va_uid);
  488         i = imgp->args->begin_envv - imgp->args->begin_argv;
  489         /* Cache arguments if they fit inside our allowance */
  490         if (ps_arg_cache_limit >= i + sizeof(struct pargs)) {
  491                 newargs = pargs_alloc(i);
  492                 bcopy(imgp->args->begin_argv, newargs->ar_args, i);
  493         }
  494 
  495         /* close files on exec */
  496         fdcloseexec(td);
  497 
  498         /* Get a reference to the vnode prior to locking the proc */
  499         VREF(ndp->ni_vp);
  500 
  501         /*
  502          * For security and other reasons, signal handlers cannot
  503          * be shared after an exec. The new process gets a copy of the old
  504          * handlers. In execsigs(), the new process will have its signals
  505          * reset.
  506          */
  507         PROC_LOCK(p);
  508         if (sigacts_shared(p->p_sigacts)) {
  509                 oldsigacts = p->p_sigacts;
  510                 PROC_UNLOCK(p);
  511                 newsigacts = sigacts_alloc();
  512                 sigacts_copy(newsigacts, oldsigacts);
  513                 PROC_LOCK(p);
  514                 p->p_sigacts = newsigacts;
  515         } else
  516                 oldsigacts = NULL;
  517 
  518         /* Stop profiling */
  519         stopprofclock(p);
  520 
  521         /* reset caught signals */
  522         execsigs(p);
  523 
  524         /* name this process - nameiexec(p, ndp) */
  525         len = min(ndp->ni_cnd.cn_namelen,MAXCOMLEN);
  526         bcopy(ndp->ni_cnd.cn_nameptr, p->p_comm, len);
  527         p->p_comm[len] = 0;
  528 
  529         /*
  530          * mark as execed, wakeup the process that vforked (if any) and tell
  531          * it that it now has its own resources back
  532          */
  533         p->p_flag |= P_EXEC;
  534         if (p->p_pptr && (p->p_flag & P_PPWAIT)) {
  535                 p->p_flag &= ~P_PPWAIT;
  536                 wakeup(p->p_pptr);
  537         }
  538 
  539         /*
  540          * Implement image setuid/setgid.
  541          *
  542          * Don't honor setuid/setgid if the filesystem prohibits it or if
  543          * the process is being traced.
  544          *
  545          * XXXMAC: For the time being, use NOSUID to also prohibit
  546          * transitions on the file system.
  547          */
  548         oldcred = p->p_ucred;
  549         credential_changing = 0;
  550         credential_changing |= (attr.va_mode & VSUID) && oldcred->cr_uid !=
  551             attr.va_uid;
  552         credential_changing |= (attr.va_mode & VSGID) && oldcred->cr_gid !=
  553             attr.va_gid;
  554 #ifdef MAC
  555         will_transition = mac_execve_will_transition(oldcred, imgp->vp,
  556             interplabel, imgp);
  557         credential_changing |= will_transition;
  558 #endif
  559 
  560         if (credential_changing &&
  561             (imgp->vp->v_mount->mnt_flag & MNT_NOSUID) == 0 &&
  562             (p->p_flag & P_TRACED) == 0) {
  563                 /*
  564                  * Turn off syscall tracing for set-id programs, except for
  565                  * root.  Record any set-id flags first to make sure that
  566                  * we do not regain any tracing during a possible block.
  567                  */
  568                 setsugid(p);
  569 #ifdef KTRACE
  570                 if (p->p_tracevp != NULL && suser_cred(oldcred, SUSER_ALLOWJAIL)) {
  571                         mtx_lock(&ktrace_mtx);
  572                         p->p_traceflag = 0;
  573                         tracevp = p->p_tracevp;
  574                         p->p_tracevp = NULL;
  575                         tracecred = p->p_tracecred;
  576                         p->p_tracecred = NULL;
  577                         mtx_unlock(&ktrace_mtx);
  578                 }
  579 #endif
  580                 /*
  581                  * Close any file descriptors 0..2 that reference procfs,
  582                  * then make sure file descriptors 0..2 are in use.
  583                  *
  584                  * setugidsafety() may call closef() and then pfind()
  585                  * which may grab the process lock.
  586                  * fdcheckstd() may call falloc() which may block to
  587                  * allocate memory, so temporarily drop the process lock.
  588                  */
  589                 PROC_UNLOCK(p);
  590                 setugidsafety(td);
  591                 error = fdcheckstd(td);
  592                 if (error != 0)
  593                         goto done1;
  594                 PROC_LOCK(p);
  595                 /*
  596                  * Set the new credentials.
  597                  */
  598                 crcopy(newcred, oldcred);
  599                 if (attr.va_mode & VSUID)
  600                         change_euid(newcred, euip);
  601                 if (attr.va_mode & VSGID)
  602                         change_egid(newcred, attr.va_gid);
  603 #ifdef MAC
  604                 if (will_transition) {
  605                         mac_execve_transition(oldcred, newcred, imgp->vp,
  606                             interplabel, imgp);
  607                 }
  608 #endif
  609                 /*
  610                  * Implement correct POSIX saved-id behavior.
  611                  *
  612                  * XXXMAC: Note that the current logic will save the
  613                  * uid and gid if a MAC domain transition occurs, even
  614                  * though maybe it shouldn't.
  615                  */
  616                 change_svuid(newcred, newcred->cr_uid);
  617                 change_svgid(newcred, newcred->cr_gid);
  618                 p->p_ucred = newcred;
  619                 newcred = NULL;
  620         } else {
  621                 if (oldcred->cr_uid == oldcred->cr_ruid &&
  622                     oldcred->cr_gid == oldcred->cr_rgid)
  623                         p->p_flag &= ~P_SUGID;
  624                 /*
  625                  * Implement correct POSIX saved-id behavior.
  626                  *
  627                  * XXX: It's not clear that the existing behavior is
  628                  * POSIX-compliant.  A number of sources indicate that the
  629                  * saved uid/gid should only be updated if the new ruid is
  630                  * not equal to the old ruid, or the new euid is not equal
  631                  * to the old euid and the new euid is not equal to the old
  632                  * ruid.  The FreeBSD code always updates the saved uid/gid.
  633                  * Also, this code uses the new (replaced) euid and egid as
  634                  * the source, which may or may not be the right ones to use.
  635                  */
  636                 if (oldcred->cr_svuid != oldcred->cr_uid ||
  637                     oldcred->cr_svgid != oldcred->cr_gid) {
  638                         crcopy(newcred, oldcred);
  639                         change_svuid(newcred, newcred->cr_uid);
  640                         change_svgid(newcred, newcred->cr_gid);
  641                         p->p_ucred = newcred;
  642                         newcred = NULL;
  643                 }
  644         }
  645 
  646         /*
  647          * Store the vp for use in procfs.  This vnode was referenced prior
  648          * to locking the proc lock.
  649          */
  650         textvp = p->p_textvp;
  651         p->p_textvp = ndp->ni_vp;
  652 
  653         /*
  654          * Notify others that we exec'd, and clear the P_INEXEC flag
  655          * as we're now a bona fide freshly-execed process.
  656          */
  657         KNOTE_LOCKED(&p->p_klist, NOTE_EXEC);
  658         p->p_flag &= ~P_INEXEC;
  659 
  660         /*
  661          * If tracing the process, trap to debugger so breakpoints
  662          * can be set before the program executes.
  663          * Use tdsignal to deliver signal to current thread, use
  664          * psignal may cause the signal to be delivered to wrong thread
  665          * because that thread will exit, remember we are going to enter
  666          * single thread mode.
  667          */
  668         if (p->p_flag & P_TRACED)
  669                 tdsignal(td, SIGTRAP, SIGTARGET_TD);
  670 
  671         /* clear "fork but no exec" flag, as we _are_ execing */
  672         p->p_acflag &= ~AFORK;
  673 
  674         /*
  675          * Free any previous argument cache and replace it with
  676          * the new argument cache, if any.
  677          */
  678         oldargs = p->p_args;
  679         p->p_args = newargs;
  680         newargs = NULL;
  681 
  682 #ifdef  HWPMC_HOOKS
  683         /*
  684          * Check if system-wide sampling is in effect or if the
  685          * current process is using PMCs.  If so, do exec() time
  686          * processing.  This processing needs to happen AFTER the
  687          * P_INEXEC flag is cleared.
  688          *
  689          * The proc lock needs to be released before taking the PMC
  690          * SX.
  691          */
  692         if (PMC_SYSTEM_SAMPLING_ACTIVE() || PMC_PROC_IS_USING_PMCS(p)) {
  693                 PROC_UNLOCK(p);
  694                 pe.pm_credentialschanged = credential_changing;
  695                 pe.pm_entryaddr = imgp->entry_addr;
  696 
  697                 PMC_CALL_HOOK_X(td, PMC_FN_PROCESS_EXEC, (void *) &pe);
  698         } else
  699                 PROC_UNLOCK(p);
  700 #else  /* !HWPMC_HOOKS */
  701         PROC_UNLOCK(p);
  702 #endif
  703 
  704         /* Set values passed into the program in registers. */
  705         if (p->p_sysent->sv_setregs)
  706                 (*p->p_sysent->sv_setregs)(td, imgp->entry_addr,
  707                     (u_long)(uintptr_t)stack_base, imgp->ps_strings);
  708         else
  709                 exec_setregs(td, imgp->entry_addr,
  710                     (u_long)(uintptr_t)stack_base, imgp->ps_strings);
  711 
  712         /*
  713          * Here we should update the access time of the file.  This must
  714          * be implemented by the underlying filesystem in the same way as
  715          * access timestamps for a VOP_READ() because we want to avoid
  716          * blocking and/or I/O, and have not called vn_start_write().
  717          */
  718         if ((imgp->vp->v_mount->mnt_flag & (MNT_NOATIME | MNT_RDONLY)) == 0) {
  719                 VATTR_NULL(&atimeattr);
  720                 atimeattr.va_vaflags |= VA_EXECVE_ATIME;
  721                 (void)VOP_SETATTR(imgp->vp, &atimeattr, td->td_ucred, td);
  722         }
  723 
  724 done1:
  725         /*
  726          * Free any resources malloc'd earlier that we didn't use.
  727          */
  728         uifree(euip);
  729         if (newcred == NULL)
  730                 crfree(oldcred);
  731         else
  732                 crfree(newcred);
  733         /*
  734          * Handle deferred decrement of ref counts.
  735          */
  736         if (textvp != NULL)
  737                 vrele(textvp);
  738         if (ndp->ni_vp && error != 0)
  739                 vrele(ndp->ni_vp);
  740 #ifdef KTRACE
  741         if (tracevp != NULL)
  742                 vrele(tracevp);
  743         if (tracecred != NULL)
  744                 crfree(tracecred);
  745 #endif
  746         if (oldargs != NULL)
  747                 pargs_drop(oldargs);
  748         if (newargs != NULL)
  749                 pargs_drop(newargs);
  750         if (oldsigacts != NULL)
  751                 sigacts_free(oldsigacts);
  752 
  753 exec_fail_dealloc:
  754 
  755         /*
  756          * free various allocated resources
  757          */
  758         if (imgp->firstpage != NULL)
  759                 exec_unmap_first_page(imgp);
  760 
  761         if (imgp->vp != NULL) {
  762                 NDFREE(ndp, NDF_ONLY_PNBUF);
  763                 vput(imgp->vp);
  764         }
  765 
  766         if (imgp->object != NULL)
  767                 vm_object_deallocate(imgp->object);
  768 
  769         if (error == 0) {
  770                 /*
  771                  * Stop the process here if its stop event mask has
  772                  * the S_EXEC bit set.
  773                  */
  774                 STOPEVENT(p, S_EXEC, 0);
  775                 goto done2;
  776         }
  777 
  778 exec_fail:
  779         /* we're done here, clear P_INEXEC */
  780         PROC_LOCK(p);
  781         p->p_flag &= ~P_INEXEC;
  782         PROC_UNLOCK(p);
  783 
  784         if (imgp->vmspace_destroyed) {
  785                 /* sorry, no more process anymore. exit gracefully */
  786 #ifdef MAC
  787                 mac_execve_exit(imgp);
  788                 if (interplabel != NULL)
  789                         mac_vnode_label_free(interplabel);
  790 #endif
  791                 VFS_UNLOCK_GIANT(vfslocked);
  792                 exec_free_args(args);
  793                 exit1(td, W_EXITCODE(0, SIGABRT));
  794                 /* NOT REACHED */
  795                 error = 0;
  796         }
  797 done2:
  798 #ifdef MAC
  799         mac_execve_exit(imgp);
  800         if (interplabel != NULL)
  801                 mac_vnode_label_free(interplabel);
  802 #endif
  803         VFS_UNLOCK_GIANT(vfslocked);
  804         return (error);
  805 }
  806 
  807 int
  808 exec_map_first_page(imgp)
  809         struct image_params *imgp;
  810 {
  811         int rv, i;
  812         int initial_pagein;
  813         vm_page_t ma[VM_INITIAL_PAGEIN];
  814         vm_object_t object;
  815 
  816         if (imgp->firstpage != NULL)
  817                 exec_unmap_first_page(imgp);
  818 
  819         object = imgp->vp->v_object;
  820         if (object == NULL)
  821                 return (EACCES);
  822         VM_OBJECT_LOCK(object);
  823         ma[0] = vm_page_grab(object, 0, VM_ALLOC_NORMAL | VM_ALLOC_RETRY);
  824         if ((ma[0]->valid & VM_PAGE_BITS_ALL) != VM_PAGE_BITS_ALL) {
  825                 initial_pagein = VM_INITIAL_PAGEIN;
  826                 if (initial_pagein > object->size)
  827                         initial_pagein = object->size;
  828                 for (i = 1; i < initial_pagein; i++) {
  829                         if ((ma[i] = vm_page_lookup(object, i)) != NULL) {
  830                                 if (ma[i]->valid)
  831                                         break;
  832                                 vm_page_lock_queues();
  833                                 if ((ma[i]->flags & PG_BUSY) || ma[i]->busy) {
  834                                         vm_page_unlock_queues();
  835                                         break;
  836                                 }
  837                                 vm_page_busy(ma[i]);
  838                                 vm_page_unlock_queues();
  839                         } else {
  840                                 ma[i] = vm_page_alloc(object, i,
  841                                     VM_ALLOC_NORMAL);
  842                                 if (ma[i] == NULL)
  843                                         break;
  844                         }
  845                 }
  846                 initial_pagein = i;
  847                 rv = vm_pager_get_pages(object, ma, initial_pagein, 0);
  848                 ma[0] = vm_page_lookup(object, 0);
  849                 if ((rv != VM_PAGER_OK) || (ma[0] == NULL) ||
  850                     (ma[0]->valid == 0)) {
  851                         if (ma[0]) {
  852                                 vm_page_lock_queues();
  853                                 pmap_remove_all(ma[0]);
  854                                 vm_page_free(ma[0]);
  855                                 vm_page_unlock_queues();
  856                         }
  857                         VM_OBJECT_UNLOCK(object);
  858                         return (EIO);
  859                 }
  860         }
  861         vm_page_lock_queues();
  862         vm_page_hold(ma[0]);
  863         vm_page_wakeup(ma[0]);
  864         vm_page_unlock_queues();
  865         VM_OBJECT_UNLOCK(object);
  866 
  867         imgp->firstpage = sf_buf_alloc(ma[0], 0);
  868         imgp->image_header = (char *)sf_buf_kva(imgp->firstpage);
  869 
  870         return (0);
  871 }
  872 
  873 void
  874 exec_unmap_first_page(imgp)
  875         struct image_params *imgp;
  876 {
  877         vm_page_t m;
  878 
  879         if (imgp->firstpage != NULL) {
  880                 m = sf_buf_page(imgp->firstpage);
  881                 sf_buf_free(imgp->firstpage);
  882                 imgp->firstpage = NULL;
  883                 vm_page_lock_queues();
  884                 vm_page_unhold(m);
  885                 vm_page_unlock_queues();
  886         }
  887 }
  888 
  889 /*
  890  * Destroy old address space, and allocate a new stack
  891  *      The new stack is only SGROWSIZ large because it is grown
  892  *      automatically in trap.c.
  893  */
  894 int
  895 exec_new_vmspace(imgp, sv)
  896         struct image_params *imgp;
  897         struct sysentvec *sv;
  898 {
  899         int error;
  900         struct proc *p = imgp->proc;
  901         struct vmspace *vmspace = p->p_vmspace;
  902         vm_offset_t stack_addr;
  903         vm_map_t map;
  904 
  905         imgp->vmspace_destroyed = 1;
  906 
  907         /* Called with Giant held, do not depend on it! */
  908         EVENTHANDLER_INVOKE(process_exec, p);
  909 
  910         /*
  911          * Here is as good a place as any to do any resource limit cleanups.
  912          * This is needed if a 64 bit binary exec's a 32 bit binary - the
  913          * data size limit may need to be changed to a value that makes
  914          * sense for the 32 bit binary.
  915          */
  916         if (sv->sv_fixlimits != NULL)
  917                 sv->sv_fixlimits(imgp);
  918 
  919         /*
  920          * Blow away entire process VM, if address space not shared,
  921          * otherwise, create a new VM space so that other threads are
  922          * not disrupted
  923          */
  924         map = &vmspace->vm_map;
  925         if (vmspace->vm_refcnt == 1 && vm_map_min(map) == sv->sv_minuser &&
  926             vm_map_max(map) == sv->sv_maxuser) {
  927                 shmexit(vmspace);
  928                 pmap_remove_pages(vmspace_pmap(vmspace), vm_map_min(map),
  929                     vm_map_max(map));
  930                 vm_map_remove(map, vm_map_min(map), vm_map_max(map));
  931         } else {
  932                 vmspace_exec(p, sv->sv_minuser, sv->sv_maxuser);
  933                 vmspace = p->p_vmspace;
  934                 map = &vmspace->vm_map;
  935         }
  936 
  937         /* Allocate a new stack */
  938         stack_addr = sv->sv_usrstack - maxssiz;
  939         error = vm_map_stack(map, stack_addr, (vm_size_t)maxssiz,
  940             sv->sv_stackprot, VM_PROT_ALL, MAP_STACK_GROWS_DOWN);
  941         if (error)
  942                 return (error);
  943 
  944 #ifdef __ia64__
  945         /* Allocate a new register stack */
  946         stack_addr = IA64_BACKINGSTORE;
  947         error = vm_map_stack(map, stack_addr, (vm_size_t)maxssiz,
  948             sv->sv_stackprot, VM_PROT_ALL, MAP_STACK_GROWS_UP);
  949         if (error)
  950                 return (error);
  951 #endif
  952 
  953         /* vm_ssize and vm_maxsaddr are somewhat antiquated concepts in the
  954          * VM_STACK case, but they are still used to monitor the size of the
  955          * process stack so we can check the stack rlimit.
  956          */
  957         vmspace->vm_ssize = sgrowsiz >> PAGE_SHIFT;
  958         vmspace->vm_maxsaddr = (char *)sv->sv_usrstack - maxssiz;
  959 
  960         return (0);
  961 }
  962 
  963 /*
  964  * Copy out argument and environment strings from the old process
  965  *      address space into the temporary string buffer.
  966  */
  967 int
  968 exec_copyin_args(struct image_args *args, char *fname,
  969     enum uio_seg segflg, char **argv, char **envv)
  970 {
  971         char *argp, *envp;
  972         int error;
  973         size_t length;
  974 
  975         error = 0;
  976 
  977         bzero(args, sizeof(*args));
  978         if (argv == NULL)
  979                 return (EFAULT);
  980         /*
  981          * Allocate temporary demand zeroed space for argument and
  982          *      environment strings:
  983          *
  984          * o ARG_MAX for argument and environment;
  985          * o MAXSHELLCMDLEN for the name of interpreters.
  986          */
  987         args->buf = (char *) kmem_alloc_wait(exec_map,
  988             PATH_MAX + ARG_MAX + MAXSHELLCMDLEN);
  989         if (args->buf == NULL)
  990                 return (ENOMEM);
  991         args->begin_argv = args->buf;
  992         args->endp = args->begin_argv;
  993         args->stringspace = ARG_MAX;
  994 
  995         args->fname = args->buf + ARG_MAX;
  996 
  997         /*
  998          * Copy the file name.
  999          */
 1000         error = (segflg == UIO_SYSSPACE) ?
 1001             copystr(fname, args->fname, PATH_MAX, &length) :
 1002             copyinstr(fname, args->fname, PATH_MAX, &length);
 1003         if (error != 0)
 1004                 return (error);
 1005 
 1006         /*
 1007          * extract arguments first
 1008          */
 1009         while ((argp = (caddr_t) (intptr_t) fuword(argv++))) {
 1010                 if (argp == (caddr_t) -1)
 1011                         return (EFAULT);
 1012                 if ((error = copyinstr(argp, args->endp,
 1013                     args->stringspace, &length))) {
 1014                         if (error == ENAMETOOLONG)
 1015                                 return (E2BIG);
 1016                         return (error);
 1017                 }
 1018                 args->stringspace -= length;
 1019                 args->endp += length;
 1020                 args->argc++;
 1021         }
 1022 
 1023         args->begin_envv = args->endp;
 1024 
 1025         /*
 1026          * extract environment strings
 1027          */
 1028         if (envv) {
 1029                 while ((envp = (caddr_t)(intptr_t)fuword(envv++))) {
 1030                         if (envp == (caddr_t)-1)
 1031                                 return (EFAULT);
 1032                         if ((error = copyinstr(envp, args->endp,
 1033                             args->stringspace, &length))) {
 1034                                 if (error == ENAMETOOLONG)
 1035                                         return (E2BIG);
 1036                                 return (error);
 1037                         }
 1038                         args->stringspace -= length;
 1039                         args->endp += length;
 1040                         args->envc++;
 1041                 }
 1042         }
 1043 
 1044         return (0);
 1045 }
 1046 
 1047 void
 1048 exec_free_args(struct image_args *args)
 1049 {
 1050 
 1051         if (args->buf) {
 1052                 kmem_free_wakeup(exec_map, (vm_offset_t)args->buf,
 1053                     PATH_MAX + ARG_MAX + MAXSHELLCMDLEN);
 1054                 args->buf = NULL;
 1055         }
 1056 }
 1057 
 1058 /*
 1059  * Copy strings out to the new process address space, constructing
 1060  *      new arg and env vector tables. Return a pointer to the base
 1061  *      so that it can be used as the initial stack pointer.
 1062  */
 1063 register_t *
 1064 exec_copyout_strings(imgp)
 1065         struct image_params *imgp;
 1066 {
 1067         int argc, envc;
 1068         char **vectp;
 1069         char *stringp, *destp;
 1070         register_t *stack_base;
 1071         struct ps_strings *arginfo;
 1072         struct proc *p;
 1073         int szsigcode;
 1074 
 1075         /*
 1076          * Calculate string base and vector table pointers.
 1077          * Also deal with signal trampoline code for this exec type.
 1078          */
 1079         p = imgp->proc;
 1080         szsigcode = 0;
 1081         arginfo = (struct ps_strings *)p->p_sysent->sv_psstrings;
 1082         if (p->p_sysent->sv_szsigcode != NULL)
 1083                 szsigcode = *(p->p_sysent->sv_szsigcode);
 1084         destp = (caddr_t)arginfo - szsigcode - SPARE_USRSPACE -
 1085             roundup((ARG_MAX - imgp->args->stringspace), sizeof(char *));
 1086 
 1087         /*
 1088          * install sigcode
 1089          */
 1090         if (szsigcode)
 1091                 copyout(p->p_sysent->sv_sigcode, ((caddr_t)arginfo -
 1092                     szsigcode), szsigcode);
 1093 
 1094         /*
 1095          * If we have a valid auxargs ptr, prepare some room
 1096          * on the stack.
 1097          */
 1098         if (imgp->auxargs) {
 1099                 /*
 1100                  * 'AT_COUNT*2' is size for the ELF Auxargs data. This is for
 1101                  * lower compatibility.
 1102                  */
 1103                 imgp->auxarg_size = (imgp->auxarg_size) ? imgp->auxarg_size :
 1104                     (AT_COUNT * 2);
 1105                 /*
 1106                  * The '+ 2' is for the null pointers at the end of each of
 1107                  * the arg and env vector sets,and imgp->auxarg_size is room
 1108                  * for argument of Runtime loader.
 1109                  */
 1110                 vectp = (char **)(destp - (imgp->args->argc +
 1111                     imgp->args->envc + 2 + imgp->auxarg_size) *
 1112                     sizeof(char *));
 1113 
 1114         } else {
 1115                 /*
 1116                  * The '+ 2' is for the null pointers at the end of each of
 1117                  * the arg and env vector sets
 1118                  */
 1119                 vectp = (char **)(destp - (imgp->args->argc + imgp->args->envc + 2) *
 1120                     sizeof(char *));
 1121         }
 1122 
 1123         /*
 1124          * vectp also becomes our initial stack base
 1125          */
 1126         stack_base = (register_t *)vectp;
 1127 
 1128         stringp = imgp->args->begin_argv;
 1129         argc = imgp->args->argc;
 1130         envc = imgp->args->envc;
 1131 
 1132         /*
 1133          * Copy out strings - arguments and environment.
 1134          */
 1135         copyout(stringp, destp, ARG_MAX - imgp->args->stringspace);
 1136 
 1137         /*
 1138          * Fill in "ps_strings" struct for ps, w, etc.
 1139          */
 1140         suword(&arginfo->ps_argvstr, (long)(intptr_t)vectp);
 1141         suword(&arginfo->ps_nargvstr, argc);
 1142 
 1143         /*
 1144          * Fill in argument portion of vector table.
 1145          */
 1146         for (; argc > 0; --argc) {
 1147                 suword(vectp++, (long)(intptr_t)destp);
 1148                 while (*stringp++ != 0)
 1149                         destp++;
 1150                 destp++;
 1151         }
 1152 
 1153         /* a null vector table pointer separates the argp's from the envp's */
 1154         suword(vectp++, 0);
 1155 
 1156         suword(&arginfo->ps_envstr, (long)(intptr_t)vectp);
 1157         suword(&arginfo->ps_nenvstr, envc);
 1158 
 1159         /*
 1160          * Fill in environment portion of vector table.
 1161          */
 1162         for (; envc > 0; --envc) {
 1163                 suword(vectp++, (long)(intptr_t)destp);
 1164                 while (*stringp++ != 0)
 1165                         destp++;
 1166                 destp++;
 1167         }
 1168 
 1169         /* end of vector table is a null pointer */
 1170         suword(vectp, 0);
 1171 
 1172         return (stack_base);
 1173 }
 1174 
 1175 /*
 1176  * Check permissions of file to execute.
 1177  *      Called with imgp->vp locked.
 1178  *      Return 0 for success or error code on failure.
 1179  */
 1180 int
 1181 exec_check_permissions(imgp)
 1182         struct image_params *imgp;
 1183 {
 1184         struct vnode *vp = imgp->vp;
 1185         struct vattr *attr = imgp->attr;
 1186         struct thread *td;
 1187         int error;
 1188 
 1189         td = curthread;                 /* XXXKSE */
 1190 
 1191         /* Get file attributes */
 1192         error = VOP_GETATTR(vp, attr, td->td_ucred, td);
 1193         if (error)
 1194                 return (error);
 1195 
 1196 #ifdef MAC
 1197         error = mac_check_vnode_exec(td->td_ucred, imgp->vp, imgp);
 1198         if (error)
 1199                 return (error);
 1200 #endif
 1201         
 1202         /*
 1203          * 1) Check if file execution is disabled for the filesystem that this
 1204          *      file resides on.
 1205          * 2) Insure that at least one execute bit is on - otherwise root
 1206          *      will always succeed, and we don't want to happen unless the
 1207          *      file really is executable.
 1208          * 3) Insure that the file is a regular file.
 1209          */
 1210         if ((vp->v_mount->mnt_flag & MNT_NOEXEC) ||
 1211             ((attr->va_mode & 0111) == 0) ||
 1212             (attr->va_type != VREG))
 1213                 return (EACCES);
 1214 
 1215         /*
 1216          * Zero length files can't be exec'd
 1217          */
 1218         if (attr->va_size == 0)
 1219                 return (ENOEXEC);
 1220 
 1221         /*
 1222          *  Check for execute permission to file based on current credentials.
 1223          */
 1224         error = VOP_ACCESS(vp, VEXEC, td->td_ucred, td);
 1225         if (error)
 1226                 return (error);
 1227 
 1228         /*
 1229          * Check number of open-for-writes on the file and deny execution
 1230          * if there are any.
 1231          */
 1232         if (vp->v_writecount)
 1233                 return (ETXTBSY);
 1234 
 1235         /*
 1236          * Call filesystem specific open routine (which does nothing in the
 1237          * general case).
 1238          */
 1239         error = VOP_OPEN(vp, FREAD, td->td_ucred, td, -1);
 1240         return (error);
 1241 }
 1242 
 1243 /*
 1244  * Exec handler registration
 1245  */
 1246 int
 1247 exec_register(execsw_arg)
 1248         const struct execsw *execsw_arg;
 1249 {
 1250         const struct execsw **es, **xs, **newexecsw;
 1251         int count = 2;  /* New slot and trailing NULL */
 1252 
 1253         if (execsw)
 1254                 for (es = execsw; *es; es++)
 1255                         count++;
 1256         newexecsw = malloc(count * sizeof(*es), M_TEMP, M_WAITOK);
 1257         if (newexecsw == NULL)
 1258                 return (ENOMEM);
 1259         xs = newexecsw;
 1260         if (execsw)
 1261                 for (es = execsw; *es; es++)
 1262                         *xs++ = *es;
 1263         *xs++ = execsw_arg;
 1264         *xs = NULL;
 1265         if (execsw)
 1266                 free(execsw, M_TEMP);
 1267         execsw = newexecsw;
 1268         return (0);
 1269 }
 1270 
 1271 int
 1272 exec_unregister(execsw_arg)
 1273         const struct execsw *execsw_arg;
 1274 {
 1275         const struct execsw **es, **xs, **newexecsw;
 1276         int count = 1;
 1277 
 1278         if (execsw == NULL)
 1279                 panic("unregister with no handlers left?\n");
 1280 
 1281         for (es = execsw; *es; es++) {
 1282                 if (*es == execsw_arg)
 1283                         break;
 1284         }
 1285         if (*es == NULL)
 1286                 return (ENOENT);
 1287         for (es = execsw; *es; es++)
 1288                 if (*es != execsw_arg)
 1289                         count++;
 1290         newexecsw = malloc(count * sizeof(*es), M_TEMP, M_WAITOK);
 1291         if (newexecsw == NULL)
 1292                 return (ENOMEM);
 1293         xs = newexecsw;
 1294         for (es = execsw; *es; es++)
 1295                 if (*es != execsw_arg)
 1296                         *xs++ = *es;
 1297         *xs = NULL;
 1298         if (execsw)
 1299                 free(execsw, M_TEMP);
 1300         execsw = newexecsw;
 1301         return (0);
 1302 }

Cache object: 60dc10850ba3a3888d1b9431e8a61ce8


[ 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.