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/6.1/sys/kern/kern_exec.c 158179 2006-04-30 16:44:43Z cvs2svn $");
   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 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         vfs_mark_atime(imgp->vp, td);
  713 
  714 done1:
  715         /*
  716          * Free any resources malloc'd earlier that we didn't use.
  717          */
  718         uifree(euip);
  719         if (newcred == NULL)
  720                 crfree(oldcred);
  721         else
  722                 crfree(newcred);
  723         /*
  724          * Handle deferred decrement of ref counts.
  725          */
  726         if (textvp != NULL) {
  727                 int tvfslocked;
  728 
  729                 tvfslocked = VFS_LOCK_GIANT(textvp->v_mount);
  730                 vrele(textvp);
  731                 VFS_UNLOCK_GIANT(tvfslocked);
  732         }
  733         if (ndp->ni_vp && error != 0)
  734                 vrele(ndp->ni_vp);
  735 #ifdef KTRACE
  736         if (tracevp != NULL)
  737                 vrele(tracevp);
  738         if (tracecred != NULL)
  739                 crfree(tracecred);
  740 #endif
  741         if (oldargs != NULL)
  742                 pargs_drop(oldargs);
  743         if (newargs != NULL)
  744                 pargs_drop(newargs);
  745         if (oldsigacts != NULL)
  746                 sigacts_free(oldsigacts);
  747 
  748 exec_fail_dealloc:
  749 
  750         /*
  751          * free various allocated resources
  752          */
  753         if (imgp->firstpage != NULL)
  754                 exec_unmap_first_page(imgp);
  755 
  756         if (imgp->vp != NULL) {
  757                 NDFREE(ndp, NDF_ONLY_PNBUF);
  758                 vput(imgp->vp);
  759         }
  760 
  761         if (imgp->object != NULL)
  762                 vm_object_deallocate(imgp->object);
  763 
  764         if (error == 0) {
  765                 /*
  766                  * Stop the process here if its stop event mask has
  767                  * the S_EXEC bit set.
  768                  */
  769                 STOPEVENT(p, S_EXEC, 0);
  770                 goto done2;
  771         }
  772 
  773 exec_fail:
  774         /* we're done here, clear P_INEXEC */
  775         PROC_LOCK(p);
  776         p->p_flag &= ~P_INEXEC;
  777         PROC_UNLOCK(p);
  778 
  779         if (imgp->vmspace_destroyed) {
  780                 /* sorry, no more process anymore. exit gracefully */
  781 #ifdef MAC
  782                 mac_execve_exit(imgp);
  783                 if (interplabel != NULL)
  784                         mac_vnode_label_free(interplabel);
  785 #endif
  786                 VFS_UNLOCK_GIANT(vfslocked);
  787                 exec_free_args(args);
  788                 exit1(td, W_EXITCODE(0, SIGABRT));
  789                 /* NOT REACHED */
  790                 error = 0;
  791         }
  792 done2:
  793 #ifdef MAC
  794         mac_execve_exit(imgp);
  795         if (interplabel != NULL)
  796                 mac_vnode_label_free(interplabel);
  797 #endif
  798         VFS_UNLOCK_GIANT(vfslocked);
  799         return (error);
  800 }
  801 
  802 int
  803 exec_map_first_page(imgp)
  804         struct image_params *imgp;
  805 {
  806         int rv, i;
  807         int initial_pagein;
  808         vm_page_t ma[VM_INITIAL_PAGEIN];
  809         vm_object_t object;
  810 
  811         if (imgp->firstpage != NULL)
  812                 exec_unmap_first_page(imgp);
  813 
  814         object = imgp->vp->v_object;
  815         if (object == NULL)
  816                 return (EACCES);
  817         VM_OBJECT_LOCK(object);
  818         ma[0] = vm_page_grab(object, 0, VM_ALLOC_NORMAL | VM_ALLOC_RETRY);
  819         if ((ma[0]->valid & VM_PAGE_BITS_ALL) != VM_PAGE_BITS_ALL) {
  820                 initial_pagein = VM_INITIAL_PAGEIN;
  821                 if (initial_pagein > object->size)
  822                         initial_pagein = object->size;
  823                 for (i = 1; i < initial_pagein; i++) {
  824                         if ((ma[i] = vm_page_lookup(object, i)) != NULL) {
  825                                 if (ma[i]->valid)
  826                                         break;
  827                                 vm_page_lock_queues();
  828                                 if ((ma[i]->flags & PG_BUSY) || ma[i]->busy) {
  829                                         vm_page_unlock_queues();
  830                                         break;
  831                                 }
  832                                 vm_page_busy(ma[i]);
  833                                 vm_page_unlock_queues();
  834                         } else {
  835                                 ma[i] = vm_page_alloc(object, i,
  836                                     VM_ALLOC_NORMAL);
  837                                 if (ma[i] == NULL)
  838                                         break;
  839                         }
  840                 }
  841                 initial_pagein = i;
  842                 rv = vm_pager_get_pages(object, ma, initial_pagein, 0);
  843                 ma[0] = vm_page_lookup(object, 0);
  844                 if ((rv != VM_PAGER_OK) || (ma[0] == NULL) ||
  845                     (ma[0]->valid == 0)) {
  846                         if (ma[0]) {
  847                                 vm_page_lock_queues();
  848                                 pmap_remove_all(ma[0]);
  849                                 vm_page_free(ma[0]);
  850                                 vm_page_unlock_queues();
  851                         }
  852                         VM_OBJECT_UNLOCK(object);
  853                         return (EIO);
  854                 }
  855         }
  856         vm_page_lock_queues();
  857         vm_page_hold(ma[0]);
  858         vm_page_wakeup(ma[0]);
  859         vm_page_unlock_queues();
  860         VM_OBJECT_UNLOCK(object);
  861 
  862         imgp->firstpage = sf_buf_alloc(ma[0], 0);
  863         imgp->image_header = (char *)sf_buf_kva(imgp->firstpage);
  864 
  865         return (0);
  866 }
  867 
  868 void
  869 exec_unmap_first_page(imgp)
  870         struct image_params *imgp;
  871 {
  872         vm_page_t m;
  873 
  874         if (imgp->firstpage != NULL) {
  875                 m = sf_buf_page(imgp->firstpage);
  876                 sf_buf_free(imgp->firstpage);
  877                 imgp->firstpage = NULL;
  878                 vm_page_lock_queues();
  879                 vm_page_unhold(m);
  880                 vm_page_unlock_queues();
  881         }
  882 }
  883 
  884 /*
  885  * Destroy old address space, and allocate a new stack
  886  *      The new stack is only SGROWSIZ large because it is grown
  887  *      automatically in trap.c.
  888  */
  889 int
  890 exec_new_vmspace(imgp, sv)
  891         struct image_params *imgp;
  892         struct sysentvec *sv;
  893 {
  894         int error;
  895         struct proc *p = imgp->proc;
  896         struct vmspace *vmspace = p->p_vmspace;
  897         vm_offset_t stack_addr;
  898         vm_map_t map;
  899 
  900         imgp->vmspace_destroyed = 1;
  901 
  902         /* Called with Giant held, do not depend on it! */
  903         EVENTHANDLER_INVOKE(process_exec, p);
  904 
  905         /*
  906          * Here is as good a place as any to do any resource limit cleanups.
  907          * This is needed if a 64 bit binary exec's a 32 bit binary - the
  908          * data size limit may need to be changed to a value that makes
  909          * sense for the 32 bit binary.
  910          */
  911         if (sv->sv_fixlimits != NULL)
  912                 sv->sv_fixlimits(imgp);
  913 
  914         /*
  915          * Blow away entire process VM, if address space not shared,
  916          * otherwise, create a new VM space so that other threads are
  917          * not disrupted
  918          */
  919         map = &vmspace->vm_map;
  920         if (vmspace->vm_refcnt == 1 && vm_map_min(map) == sv->sv_minuser &&
  921             vm_map_max(map) == sv->sv_maxuser) {
  922                 shmexit(vmspace);
  923                 pmap_remove_pages(vmspace_pmap(vmspace), vm_map_min(map),
  924                     vm_map_max(map));
  925                 vm_map_remove(map, vm_map_min(map), vm_map_max(map));
  926         } else {
  927                 vmspace_exec(p, sv->sv_minuser, sv->sv_maxuser);
  928                 vmspace = p->p_vmspace;
  929                 map = &vmspace->vm_map;
  930         }
  931 
  932         /* Allocate a new stack */
  933         stack_addr = sv->sv_usrstack - maxssiz;
  934         error = vm_map_stack(map, stack_addr, (vm_size_t)maxssiz,
  935             sv->sv_stackprot, VM_PROT_ALL, MAP_STACK_GROWS_DOWN);
  936         if (error)
  937                 return (error);
  938 
  939 #ifdef __ia64__
  940         /* Allocate a new register stack */
  941         stack_addr = IA64_BACKINGSTORE;
  942         error = vm_map_stack(map, stack_addr, (vm_size_t)maxssiz,
  943             sv->sv_stackprot, VM_PROT_ALL, MAP_STACK_GROWS_UP);
  944         if (error)
  945                 return (error);
  946 #endif
  947 
  948         /* vm_ssize and vm_maxsaddr are somewhat antiquated concepts in the
  949          * VM_STACK case, but they are still used to monitor the size of the
  950          * process stack so we can check the stack rlimit.
  951          */
  952         vmspace->vm_ssize = sgrowsiz >> PAGE_SHIFT;
  953         vmspace->vm_maxsaddr = (char *)sv->sv_usrstack - maxssiz;
  954 
  955         return (0);
  956 }
  957 
  958 /*
  959  * Copy out argument and environment strings from the old process
  960  *      address space into the temporary string buffer.
  961  */
  962 int
  963 exec_copyin_args(struct image_args *args, char *fname,
  964     enum uio_seg segflg, char **argv, char **envv)
  965 {
  966         char *argp, *envp;
  967         int error;
  968         size_t length;
  969 
  970         error = 0;
  971 
  972         bzero(args, sizeof(*args));
  973         if (argv == NULL)
  974                 return (EFAULT);
  975         /*
  976          * Allocate temporary demand zeroed space for argument and
  977          *      environment strings:
  978          *
  979          * o ARG_MAX for argument and environment;
  980          * o MAXSHELLCMDLEN for the name of interpreters.
  981          */
  982         args->buf = (char *) kmem_alloc_wait(exec_map,
  983             PATH_MAX + ARG_MAX + MAXSHELLCMDLEN);
  984         if (args->buf == NULL)
  985                 return (ENOMEM);
  986         args->begin_argv = args->buf;
  987         args->endp = args->begin_argv;
  988         args->stringspace = ARG_MAX;
  989 
  990         args->fname = args->buf + ARG_MAX;
  991 
  992         /*
  993          * Copy the file name.
  994          */
  995         error = (segflg == UIO_SYSSPACE) ?
  996             copystr(fname, args->fname, PATH_MAX, &length) :
  997             copyinstr(fname, args->fname, PATH_MAX, &length);
  998         if (error != 0)
  999                 return (error);
 1000 
 1001         /*
 1002          * extract arguments first
 1003          */
 1004         while ((argp = (caddr_t) (intptr_t) fuword(argv++))) {
 1005                 if (argp == (caddr_t) -1)
 1006                         return (EFAULT);
 1007                 if ((error = copyinstr(argp, args->endp,
 1008                     args->stringspace, &length))) {
 1009                         if (error == ENAMETOOLONG)
 1010                                 return (E2BIG);
 1011                         return (error);
 1012                 }
 1013                 args->stringspace -= length;
 1014                 args->endp += length;
 1015                 args->argc++;
 1016         }
 1017 
 1018         args->begin_envv = args->endp;
 1019 
 1020         /*
 1021          * extract environment strings
 1022          */
 1023         if (envv) {
 1024                 while ((envp = (caddr_t)(intptr_t)fuword(envv++))) {
 1025                         if (envp == (caddr_t)-1)
 1026                                 return (EFAULT);
 1027                         if ((error = copyinstr(envp, args->endp,
 1028                             args->stringspace, &length))) {
 1029                                 if (error == ENAMETOOLONG)
 1030                                         return (E2BIG);
 1031                                 return (error);
 1032                         }
 1033                         args->stringspace -= length;
 1034                         args->endp += length;
 1035                         args->envc++;
 1036                 }
 1037         }
 1038 
 1039         return (0);
 1040 }
 1041 
 1042 void
 1043 exec_free_args(struct image_args *args)
 1044 {
 1045 
 1046         if (args->buf) {
 1047                 kmem_free_wakeup(exec_map, (vm_offset_t)args->buf,
 1048                     PATH_MAX + ARG_MAX + MAXSHELLCMDLEN);
 1049                 args->buf = NULL;
 1050         }
 1051 }
 1052 
 1053 /*
 1054  * Copy strings out to the new process address space, constructing
 1055  *      new arg and env vector tables. Return a pointer to the base
 1056  *      so that it can be used as the initial stack pointer.
 1057  */
 1058 register_t *
 1059 exec_copyout_strings(imgp)
 1060         struct image_params *imgp;
 1061 {
 1062         int argc, envc;
 1063         char **vectp;
 1064         char *stringp, *destp;
 1065         register_t *stack_base;
 1066         struct ps_strings *arginfo;
 1067         struct proc *p;
 1068         int szsigcode;
 1069 
 1070         /*
 1071          * Calculate string base and vector table pointers.
 1072          * Also deal with signal trampoline code for this exec type.
 1073          */
 1074         p = imgp->proc;
 1075         szsigcode = 0;
 1076         arginfo = (struct ps_strings *)p->p_sysent->sv_psstrings;
 1077         if (p->p_sysent->sv_szsigcode != NULL)
 1078                 szsigcode = *(p->p_sysent->sv_szsigcode);
 1079         destp = (caddr_t)arginfo - szsigcode - SPARE_USRSPACE -
 1080             roundup((ARG_MAX - imgp->args->stringspace), sizeof(char *));
 1081 
 1082         /*
 1083          * install sigcode
 1084          */
 1085         if (szsigcode)
 1086                 copyout(p->p_sysent->sv_sigcode, ((caddr_t)arginfo -
 1087                     szsigcode), szsigcode);
 1088 
 1089         /*
 1090          * If we have a valid auxargs ptr, prepare some room
 1091          * on the stack.
 1092          */
 1093         if (imgp->auxargs) {
 1094                 /*
 1095                  * 'AT_COUNT*2' is size for the ELF Auxargs data. This is for
 1096                  * lower compatibility.
 1097                  */
 1098                 imgp->auxarg_size = (imgp->auxarg_size) ? imgp->auxarg_size :
 1099                     (AT_COUNT * 2);
 1100                 /*
 1101                  * The '+ 2' is for the null pointers at the end of each of
 1102                  * the arg and env vector sets,and imgp->auxarg_size is room
 1103                  * for argument of Runtime loader.
 1104                  */
 1105                 vectp = (char **)(destp - (imgp->args->argc +
 1106                     imgp->args->envc + 2 + imgp->auxarg_size) *
 1107                     sizeof(char *));
 1108 
 1109         } else {
 1110                 /*
 1111                  * The '+ 2' is for the null pointers at the end of each of
 1112                  * the arg and env vector sets
 1113                  */
 1114                 vectp = (char **)(destp - (imgp->args->argc + imgp->args->envc + 2) *
 1115                     sizeof(char *));
 1116         }
 1117 
 1118         /*
 1119          * vectp also becomes our initial stack base
 1120          */
 1121         stack_base = (register_t *)vectp;
 1122 
 1123         stringp = imgp->args->begin_argv;
 1124         argc = imgp->args->argc;
 1125         envc = imgp->args->envc;
 1126 
 1127         /*
 1128          * Copy out strings - arguments and environment.
 1129          */
 1130         copyout(stringp, destp, ARG_MAX - imgp->args->stringspace);
 1131 
 1132         /*
 1133          * Fill in "ps_strings" struct for ps, w, etc.
 1134          */
 1135         suword(&arginfo->ps_argvstr, (long)(intptr_t)vectp);
 1136         suword(&arginfo->ps_nargvstr, argc);
 1137 
 1138         /*
 1139          * Fill in argument portion of vector table.
 1140          */
 1141         for (; argc > 0; --argc) {
 1142                 suword(vectp++, (long)(intptr_t)destp);
 1143                 while (*stringp++ != 0)
 1144                         destp++;
 1145                 destp++;
 1146         }
 1147 
 1148         /* a null vector table pointer separates the argp's from the envp's */
 1149         suword(vectp++, 0);
 1150 
 1151         suword(&arginfo->ps_envstr, (long)(intptr_t)vectp);
 1152         suword(&arginfo->ps_nenvstr, envc);
 1153 
 1154         /*
 1155          * Fill in environment portion of vector table.
 1156          */
 1157         for (; envc > 0; --envc) {
 1158                 suword(vectp++, (long)(intptr_t)destp);
 1159                 while (*stringp++ != 0)
 1160                         destp++;
 1161                 destp++;
 1162         }
 1163 
 1164         /* end of vector table is a null pointer */
 1165         suword(vectp, 0);
 1166 
 1167         return (stack_base);
 1168 }
 1169 
 1170 /*
 1171  * Check permissions of file to execute.
 1172  *      Called with imgp->vp locked.
 1173  *      Return 0 for success or error code on failure.
 1174  */
 1175 int
 1176 exec_check_permissions(imgp)
 1177         struct image_params *imgp;
 1178 {
 1179         struct vnode *vp = imgp->vp;
 1180         struct vattr *attr = imgp->attr;
 1181         struct thread *td;
 1182         int error;
 1183 
 1184         td = curthread;                 /* XXXKSE */
 1185 
 1186         /* Get file attributes */
 1187         error = VOP_GETATTR(vp, attr, td->td_ucred, td);
 1188         if (error)
 1189                 return (error);
 1190 
 1191 #ifdef MAC
 1192         error = mac_check_vnode_exec(td->td_ucred, imgp->vp, imgp);
 1193         if (error)
 1194                 return (error);
 1195 #endif
 1196         
 1197         /*
 1198          * 1) Check if file execution is disabled for the filesystem that this
 1199          *      file resides on.
 1200          * 2) Insure that at least one execute bit is on - otherwise root
 1201          *      will always succeed, and we don't want to happen unless the
 1202          *      file really is executable.
 1203          * 3) Insure that the file is a regular file.
 1204          */
 1205         if ((vp->v_mount->mnt_flag & MNT_NOEXEC) ||
 1206             ((attr->va_mode & 0111) == 0) ||
 1207             (attr->va_type != VREG))
 1208                 return (EACCES);
 1209 
 1210         /*
 1211          * Zero length files can't be exec'd
 1212          */
 1213         if (attr->va_size == 0)
 1214                 return (ENOEXEC);
 1215 
 1216         /*
 1217          *  Check for execute permission to file based on current credentials.
 1218          */
 1219         error = VOP_ACCESS(vp, VEXEC, td->td_ucred, td);
 1220         if (error)
 1221                 return (error);
 1222 
 1223         /*
 1224          * Check number of open-for-writes on the file and deny execution
 1225          * if there are any.
 1226          */
 1227         if (vp->v_writecount)
 1228                 return (ETXTBSY);
 1229 
 1230         /*
 1231          * Call filesystem specific open routine (which does nothing in the
 1232          * general case).
 1233          */
 1234         error = VOP_OPEN(vp, FREAD, td->td_ucred, td, -1);
 1235         return (error);
 1236 }
 1237 
 1238 /*
 1239  * Exec handler registration
 1240  */
 1241 int
 1242 exec_register(execsw_arg)
 1243         const struct execsw *execsw_arg;
 1244 {
 1245         const struct execsw **es, **xs, **newexecsw;
 1246         int count = 2;  /* New slot and trailing NULL */
 1247 
 1248         if (execsw)
 1249                 for (es = execsw; *es; es++)
 1250                         count++;
 1251         newexecsw = malloc(count * sizeof(*es), M_TEMP, M_WAITOK);
 1252         if (newexecsw == NULL)
 1253                 return (ENOMEM);
 1254         xs = newexecsw;
 1255         if (execsw)
 1256                 for (es = execsw; *es; es++)
 1257                         *xs++ = *es;
 1258         *xs++ = execsw_arg;
 1259         *xs = NULL;
 1260         if (execsw)
 1261                 free(execsw, M_TEMP);
 1262         execsw = newexecsw;
 1263         return (0);
 1264 }
 1265 
 1266 int
 1267 exec_unregister(execsw_arg)
 1268         const struct execsw *execsw_arg;
 1269 {
 1270         const struct execsw **es, **xs, **newexecsw;
 1271         int count = 1;
 1272 
 1273         if (execsw == NULL)
 1274                 panic("unregister with no handlers left?\n");
 1275 
 1276         for (es = execsw; *es; es++) {
 1277                 if (*es == execsw_arg)
 1278                         break;
 1279         }
 1280         if (*es == NULL)
 1281                 return (ENOENT);
 1282         for (es = execsw; *es; es++)
 1283                 if (*es != execsw_arg)
 1284                         count++;
 1285         newexecsw = malloc(count * sizeof(*es), M_TEMP, M_WAITOK);
 1286         if (newexecsw == NULL)
 1287                 return (ENOMEM);
 1288         xs = newexecsw;
 1289         for (es = execsw; *es; es++)
 1290                 if (*es != execsw_arg)
 1291                         *xs++ = *es;
 1292         *xs = NULL;
 1293         if (execsw)
 1294                 free(execsw, M_TEMP);
 1295         execsw = newexecsw;
 1296         return (0);
 1297 }

Cache object: 138e0758541e4f1f9bb26a84748579dc


[ 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.