e64b1984f9
plus the previous changes to use the zone allocator decrease the useage of malloc by half. The Zone allocator will be upgradeable to be able to use per CPU-pools, and has more intelligent usage of SPLs. Additionally, it has reasonable stats gathering capabilities, while making most calls inline.
666 lines
16 KiB
C
666 lines
16 KiB
C
/*
|
|
* Copyright (c) 1993, David Greenman
|
|
* All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
|
|
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
|
|
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
* SUCH DAMAGE.
|
|
*
|
|
* $Id: kern_exec.c,v 1.65 1997/09/02 20:05:38 bde Exp $
|
|
*/
|
|
|
|
#include <sys/param.h>
|
|
#include <sys/systm.h>
|
|
#include <sys/sysproto.h>
|
|
#include <sys/signalvar.h>
|
|
#include <sys/kernel.h>
|
|
#include <sys/mount.h>
|
|
#include <sys/filedesc.h>
|
|
#include <sys/fcntl.h>
|
|
#include <sys/acct.h>
|
|
#include <sys/exec.h>
|
|
#include <sys/imgact.h>
|
|
#include <sys/imgact_elf.h>
|
|
#include <sys/wait.h>
|
|
#include <sys/proc.h>
|
|
#include <sys/malloc.h>
|
|
#include <sys/namei.h>
|
|
#include <sys/sysent.h>
|
|
#include <sys/shm.h>
|
|
#include <sys/sysctl.h>
|
|
#include <sys/vnode.h>
|
|
#include <sys/buf.h>
|
|
|
|
#include <vm/vm.h>
|
|
#include <vm/vm_param.h>
|
|
#include <vm/vm_prot.h>
|
|
#include <sys/lock.h>
|
|
#include <vm/pmap.h>
|
|
#include <vm/vm_map.h>
|
|
#include <vm/vm_kern.h>
|
|
#include <vm/vm_extern.h>
|
|
#include <vm/vm_object.h>
|
|
|
|
#include <machine/reg.h>
|
|
|
|
static int *exec_copyout_strings __P((struct image_params *));
|
|
|
|
static int exec_check_permissions(struct image_params *);
|
|
|
|
/*
|
|
* XXX trouble here if sizeof(caddr_t) != sizeof(int), other parts
|
|
* of the sysctl code also assumes this, and sizeof(int) == sizeof(long).
|
|
*/
|
|
static struct ps_strings *ps_strings = PS_STRINGS;
|
|
SYSCTL_INT(_kern, KERN_PS_STRINGS, ps_strings, 0, &ps_strings, 0, "");
|
|
|
|
static caddr_t usrstack = (caddr_t)USRSTACK;
|
|
SYSCTL_INT(_kern, KERN_USRSTACK, usrstack, 0, &usrstack, 0, "");
|
|
|
|
/*
|
|
* execsw_set is constructed for us by the linker. Each of the items
|
|
* is a pointer to a `const struct execsw', hence the double pointer here.
|
|
*/
|
|
static const struct execsw **execsw =
|
|
(const struct execsw **)&execsw_set.ls_items[0];
|
|
|
|
#ifndef _SYS_SYSPROTO_H_
|
|
struct execve_args {
|
|
char *fname;
|
|
char **argv;
|
|
char **envv;
|
|
};
|
|
#endif
|
|
|
|
/*
|
|
* execve() system call.
|
|
*/
|
|
int
|
|
execve(p, uap, retval)
|
|
struct proc *p;
|
|
register struct execve_args *uap;
|
|
int *retval;
|
|
{
|
|
struct nameidata nd, *ndp;
|
|
int *stack_base;
|
|
int error, len, i;
|
|
struct image_params image_params, *imgp;
|
|
struct vattr attr;
|
|
struct buf *bp = NULL;
|
|
|
|
imgp = &image_params;
|
|
|
|
/*
|
|
* Initialize part of the common data
|
|
*/
|
|
imgp->proc = p;
|
|
imgp->uap = uap;
|
|
imgp->attr = &attr;
|
|
imgp->image_header = NULL;
|
|
imgp->argc = imgp->envc = 0;
|
|
imgp->argv0 = NULL;
|
|
imgp->entry_addr = 0;
|
|
imgp->vmspace_destroyed = 0;
|
|
imgp->interpreted = 0;
|
|
imgp->interpreter_name[0] = '\0';
|
|
imgp->auxargs = NULL;
|
|
|
|
/*
|
|
* Allocate temporary demand zeroed space for argument and
|
|
* environment strings
|
|
*/
|
|
imgp->stringbase = (char *)kmem_alloc_wait(exec_map, ARG_MAX);
|
|
if (imgp->stringbase == NULL) {
|
|
error = ENOMEM;
|
|
goto exec_fail;
|
|
}
|
|
imgp->stringp = imgp->stringbase;
|
|
imgp->stringspace = ARG_MAX;
|
|
|
|
/*
|
|
* Translate the file name. namei() returns a vnode pointer
|
|
* in ni_vp amoung other things.
|
|
*/
|
|
ndp = &nd;
|
|
NDINIT(ndp, LOOKUP, LOCKLEAF | FOLLOW | SAVENAME,
|
|
UIO_USERSPACE, uap->fname, p);
|
|
|
|
interpret:
|
|
|
|
error = namei(ndp);
|
|
if (error) {
|
|
kmem_free_wakeup(exec_map, (vm_offset_t)imgp->stringbase, ARG_MAX);
|
|
goto exec_fail;
|
|
}
|
|
|
|
imgp->vp = ndp->ni_vp;
|
|
|
|
/*
|
|
* Check file permissions (also 'opens' file)
|
|
*/
|
|
error = exec_check_permissions(imgp);
|
|
if (error) {
|
|
VOP_UNLOCK(imgp->vp, 0, p);
|
|
goto exec_fail_dealloc;
|
|
}
|
|
|
|
/*
|
|
* Get the image header, which we define here as meaning the first
|
|
* page of the executable.
|
|
*/
|
|
if (imgp->vp->v_object && imgp->vp->v_mount &&
|
|
imgp->vp->v_mount->mnt_stat.f_iosize >= PAGE_SIZE &&
|
|
imgp->vp->v_object->un_pager.vnp.vnp_size >=
|
|
imgp->vp->v_mount->mnt_stat.f_iosize) {
|
|
/*
|
|
* Get a buffer with (at least) the first page.
|
|
*/
|
|
error = bread(imgp->vp, 0, imgp->vp->v_mount->mnt_stat.f_iosize,
|
|
p->p_ucred, &bp);
|
|
imgp->image_header = bp->b_data;
|
|
} else {
|
|
int resid;
|
|
|
|
/*
|
|
* The filesystem block size is too small, so do this the hard
|
|
* way. Malloc some space and read PAGE_SIZE worth of the image
|
|
* header into it.
|
|
*/
|
|
imgp->image_header = malloc(PAGE_SIZE, M_TEMP, M_WAITOK);
|
|
error = vn_rdwr(UIO_READ, imgp->vp, (void *)imgp->image_header, PAGE_SIZE, 0,
|
|
UIO_SYSSPACE, IO_NODELOCKED, p->p_ucred, &resid, p);
|
|
/*
|
|
* Clear out any remaining junk.
|
|
*/
|
|
if (!error && resid)
|
|
bzero((char *)imgp->image_header + PAGE_SIZE - resid, resid);
|
|
}
|
|
VOP_UNLOCK(imgp->vp, 0, p);
|
|
if (error)
|
|
goto exec_fail_dealloc;
|
|
|
|
/*
|
|
* Loop through list of image activators, calling each one.
|
|
* If there is no match, the activator returns -1. If there
|
|
* is a match, but there was an error during the activation,
|
|
* the error is returned. Otherwise 0 means success. If the
|
|
* image is interpreted, loop back up and try activating
|
|
* the interpreter.
|
|
*/
|
|
for (i = 0; execsw[i]; ++i) {
|
|
if (execsw[i]->ex_imgact)
|
|
error = (*execsw[i]->ex_imgact)(imgp);
|
|
else
|
|
continue;
|
|
if (error == -1)
|
|
continue;
|
|
if (error)
|
|
goto exec_fail_dealloc;
|
|
if (imgp->interpreted) {
|
|
/* free old bp/image_header */
|
|
if (bp != NULL) {
|
|
brelse(bp);
|
|
bp = NULL;
|
|
} else {
|
|
free((void *)imgp->image_header, M_TEMP);
|
|
imgp->image_header = NULL;
|
|
}
|
|
/* free old vnode and name buffer */
|
|
vrele(ndp->ni_vp);
|
|
zfree(namei_zone, ndp->ni_cnd.cn_pnbuf);
|
|
/* set new name to that of the interpreter */
|
|
NDINIT(ndp, LOOKUP, LOCKLEAF | FOLLOW | SAVENAME,
|
|
UIO_SYSSPACE, imgp->interpreter_name, p);
|
|
goto interpret;
|
|
}
|
|
break;
|
|
}
|
|
/* If we made it through all the activators and none matched, exit. */
|
|
if (error == -1) {
|
|
error = ENOEXEC;
|
|
goto exec_fail_dealloc;
|
|
}
|
|
|
|
/*
|
|
* Copy out strings (args and env) and initialize stack base
|
|
*/
|
|
stack_base = exec_copyout_strings(imgp);
|
|
p->p_vmspace->vm_minsaddr = (char *)stack_base;
|
|
|
|
/*
|
|
* If custom stack fixup routine present for this process
|
|
* let it do the stack setup.
|
|
* Else stuff argument count as first item on stack
|
|
*/
|
|
if (p->p_sysent->sv_fixup)
|
|
(*p->p_sysent->sv_fixup)(&stack_base, imgp);
|
|
else
|
|
suword(--stack_base, imgp->argc);
|
|
|
|
/*
|
|
* For security and other reasons, the file descriptor table cannot
|
|
* be shared after an exec.
|
|
*/
|
|
if (p->p_fd->fd_refcnt > 1) {
|
|
struct filedesc *tmp;
|
|
|
|
tmp = fdcopy(p);
|
|
fdfree(p);
|
|
p->p_fd = tmp;
|
|
}
|
|
|
|
/* close files on exec */
|
|
fdcloseexec(p);
|
|
|
|
/* reset caught signals */
|
|
execsigs(p);
|
|
|
|
/* name this process - nameiexec(p, ndp) */
|
|
len = min(ndp->ni_cnd.cn_namelen,MAXCOMLEN);
|
|
bcopy(ndp->ni_cnd.cn_nameptr, p->p_comm, len);
|
|
p->p_comm[len] = 0;
|
|
|
|
/*
|
|
* mark as execed, wakeup the process that vforked (if any) and tell
|
|
* it that it now has it's own resources back
|
|
*/
|
|
p->p_flag |= P_EXEC;
|
|
if (p->p_pptr && (p->p_flag & P_PPWAIT)) {
|
|
p->p_flag &= ~P_PPWAIT;
|
|
wakeup((caddr_t)p->p_pptr);
|
|
}
|
|
|
|
/*
|
|
* Implement image setuid/setgid.
|
|
*
|
|
* Don't honor setuid/setgid if the filesystem prohibits it or if
|
|
* the process is being traced.
|
|
*/
|
|
if ((attr.va_mode & (VSUID | VSGID)) &&
|
|
(imgp->vp->v_mount->mnt_flag & MNT_NOSUID) == 0 &&
|
|
(p->p_flag & P_TRACED) == 0) {
|
|
/*
|
|
* Turn off syscall tracing for set-id programs, except for
|
|
* root.
|
|
*/
|
|
if (p->p_tracep && suser(p->p_ucred, &p->p_acflag)) {
|
|
p->p_traceflag = 0;
|
|
vrele(p->p_tracep);
|
|
p->p_tracep = NULL;
|
|
}
|
|
/*
|
|
* Set the new credentials.
|
|
*/
|
|
p->p_ucred = crcopy(p->p_ucred);
|
|
if (attr.va_mode & VSUID)
|
|
p->p_ucred->cr_uid = attr.va_uid;
|
|
if (attr.va_mode & VSGID)
|
|
p->p_ucred->cr_groups[0] = attr.va_gid;
|
|
p->p_flag |= P_SUGID;
|
|
} else {
|
|
if (p->p_ucred->cr_uid == p->p_cred->p_ruid &&
|
|
p->p_ucred->cr_gid == p->p_cred->p_rgid)
|
|
p->p_flag &= ~P_SUGID;
|
|
}
|
|
|
|
/*
|
|
* Implement correct POSIX saved-id behavior.
|
|
*/
|
|
p->p_cred->p_svuid = p->p_ucred->cr_uid;
|
|
p->p_cred->p_svgid = p->p_ucred->cr_gid;
|
|
|
|
/*
|
|
* Store the vp for use in procfs
|
|
*/
|
|
if (p->p_textvp) /* release old reference */
|
|
vrele(p->p_textvp);
|
|
VREF(ndp->ni_vp);
|
|
p->p_textvp = ndp->ni_vp;
|
|
|
|
/*
|
|
* If tracing the process, trap to debugger so breakpoints
|
|
* can be set before the program executes.
|
|
*/
|
|
if (p->p_flag & P_TRACED)
|
|
psignal(p, SIGTRAP);
|
|
|
|
/* clear "fork but no exec" flag, as we _are_ execing */
|
|
p->p_acflag &= ~AFORK;
|
|
|
|
/* Set entry address */
|
|
setregs(p, imgp->entry_addr, (u_long)stack_base);
|
|
|
|
/*
|
|
* free various allocated resources
|
|
*/
|
|
kmem_free_wakeup(exec_map, (vm_offset_t)imgp->stringbase, ARG_MAX);
|
|
if (bp != NULL)
|
|
brelse(bp);
|
|
else if (imgp->image_header != NULL)
|
|
free((void *)imgp->image_header, M_TEMP);
|
|
vrele(ndp->ni_vp);
|
|
zfree(namei_zone, ndp->ni_cnd.cn_pnbuf);
|
|
|
|
return (0);
|
|
|
|
exec_fail_dealloc:
|
|
if (imgp->stringbase != NULL)
|
|
kmem_free_wakeup(exec_map, (vm_offset_t)imgp->stringbase, ARG_MAX);
|
|
if (bp != NULL)
|
|
brelse(bp);
|
|
else if (imgp->image_header != NULL)
|
|
free((void *)imgp->image_header, M_TEMP);
|
|
if (ndp->ni_vp) {
|
|
vrele(ndp->ni_vp);
|
|
zfree(namei_zone, ndp->ni_cnd.cn_pnbuf);
|
|
}
|
|
|
|
exec_fail:
|
|
if (imgp->vmspace_destroyed) {
|
|
/* sorry, no more process anymore. exit gracefully */
|
|
exit1(p, W_EXITCODE(0, SIGABRT));
|
|
/* NOT REACHED */
|
|
return(0);
|
|
} else {
|
|
return(error);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Destroy old address space, and allocate a new stack
|
|
* The new stack is only SGROWSIZ large because it is grown
|
|
* automatically in trap.c.
|
|
*/
|
|
int
|
|
exec_new_vmspace(imgp)
|
|
struct image_params *imgp;
|
|
{
|
|
int error;
|
|
struct vmspace *vmspace = imgp->proc->p_vmspace;
|
|
caddr_t stack_addr = (caddr_t) (USRSTACK - SGROWSIZ);
|
|
vm_map_t map = &vmspace->vm_map;
|
|
|
|
imgp->vmspace_destroyed = 1;
|
|
|
|
/*
|
|
* Blow away entire process VM, if address space not shared,
|
|
* otherwise, create a new VM space so that other threads are
|
|
* not disrupted
|
|
*/
|
|
if (vmspace->vm_refcnt == 1) {
|
|
if (vmspace->vm_shm)
|
|
shmexit(imgp->proc);
|
|
pmap_remove_pages(&vmspace->vm_pmap, 0, USRSTACK);
|
|
vm_map_remove(map, 0, USRSTACK);
|
|
} else {
|
|
vmspace_exec(imgp->proc);
|
|
vmspace = imgp->proc->p_vmspace;
|
|
map = &vmspace->vm_map;
|
|
}
|
|
|
|
/* Allocate a new stack */
|
|
error = vm_map_find(map, NULL, 0, (vm_offset_t *)&stack_addr,
|
|
SGROWSIZ, FALSE, VM_PROT_ALL, VM_PROT_ALL, 0);
|
|
if (error)
|
|
return(error);
|
|
|
|
vmspace->vm_ssize = SGROWSIZ >> PAGE_SHIFT;
|
|
|
|
/* Initialize maximum stack address */
|
|
vmspace->vm_maxsaddr = (char *)USRSTACK - MAXSSIZ;
|
|
|
|
return(0);
|
|
}
|
|
|
|
/*
|
|
* Copy out argument and environment strings from the old process
|
|
* address space into the temporary string buffer.
|
|
*/
|
|
int
|
|
exec_extract_strings(imgp)
|
|
struct image_params *imgp;
|
|
{
|
|
char **argv, **envv;
|
|
char *argp, *envp;
|
|
int error, length;
|
|
|
|
/*
|
|
* extract arguments first
|
|
*/
|
|
|
|
argv = imgp->uap->argv;
|
|
|
|
if (argv) {
|
|
argp = (caddr_t) fuword(argv);
|
|
if (argp == (caddr_t) -1)
|
|
return (EFAULT);
|
|
if (argp)
|
|
argv++;
|
|
if (imgp->argv0)
|
|
argp = imgp->argv0;
|
|
if (argp) {
|
|
do {
|
|
if (argp == (caddr_t) -1)
|
|
return (EFAULT);
|
|
if ((error = copyinstr(argp, imgp->stringp,
|
|
imgp->stringspace, &length))) {
|
|
if (error == ENAMETOOLONG)
|
|
return(E2BIG);
|
|
return (error);
|
|
}
|
|
imgp->stringspace -= length;
|
|
imgp->stringp += length;
|
|
imgp->argc++;
|
|
} while ((argp = (caddr_t) fuword(argv++)));
|
|
}
|
|
}
|
|
|
|
/*
|
|
* extract environment strings
|
|
*/
|
|
|
|
envv = imgp->uap->envv;
|
|
|
|
if (envv) {
|
|
while ((envp = (caddr_t) fuword(envv++))) {
|
|
if (envp == (caddr_t) -1)
|
|
return (EFAULT);
|
|
if ((error = copyinstr(envp, imgp->stringp,
|
|
imgp->stringspace, &length))) {
|
|
if (error == ENAMETOOLONG)
|
|
return(E2BIG);
|
|
return (error);
|
|
}
|
|
imgp->stringspace -= length;
|
|
imgp->stringp += length;
|
|
imgp->envc++;
|
|
}
|
|
}
|
|
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Copy strings out to the new process address space, constructing
|
|
* new arg and env vector tables. Return a pointer to the base
|
|
* so that it can be used as the initial stack pointer.
|
|
*/
|
|
int *
|
|
exec_copyout_strings(imgp)
|
|
struct image_params *imgp;
|
|
{
|
|
int argc, envc;
|
|
char **vectp;
|
|
char *stringp, *destp;
|
|
int *stack_base;
|
|
struct ps_strings *arginfo;
|
|
int szsigcode;
|
|
|
|
/*
|
|
* Calculate string base and vector table pointers.
|
|
* Also deal with signal trampoline code for this exec type.
|
|
*/
|
|
arginfo = PS_STRINGS;
|
|
szsigcode = *(imgp->proc->p_sysent->sv_szsigcode);
|
|
destp = (caddr_t)arginfo - szsigcode - SPARE_USRSPACE -
|
|
roundup((ARG_MAX - imgp->stringspace), sizeof(char *));
|
|
|
|
/*
|
|
* install sigcode
|
|
*/
|
|
if (szsigcode)
|
|
copyout(imgp->proc->p_sysent->sv_sigcode,
|
|
((caddr_t)arginfo - szsigcode), szsigcode);
|
|
|
|
/*
|
|
* If we have a valid auxargs ptr, prepare some room
|
|
* on the stack.
|
|
*/
|
|
if (imgp->auxargs)
|
|
/*
|
|
* The '+ 2' is for the null pointers at the end of each of the
|
|
* arg and env vector sets, and 'AT_COUNT*2' is room for the
|
|
* ELF Auxargs data.
|
|
*/
|
|
vectp = (char **)(destp - (imgp->argc + imgp->envc + 2 +
|
|
AT_COUNT*2) * sizeof(char*));
|
|
else
|
|
/*
|
|
* The '+ 2' is for the null pointers at the end of each of the
|
|
* arg and env vector sets
|
|
*/
|
|
vectp = (char **)
|
|
(destp - (imgp->argc + imgp->envc + 2) * sizeof(char*));
|
|
|
|
/*
|
|
* vectp also becomes our initial stack base
|
|
*/
|
|
stack_base = (int *)vectp;
|
|
|
|
stringp = imgp->stringbase;
|
|
argc = imgp->argc;
|
|
envc = imgp->envc;
|
|
|
|
/*
|
|
* Copy out strings - arguments and environment.
|
|
*/
|
|
copyout(stringp, destp, ARG_MAX - imgp->stringspace);
|
|
|
|
/*
|
|
* Fill in "ps_strings" struct for ps, w, etc.
|
|
*/
|
|
suword(&arginfo->ps_argvstr, (int)vectp);
|
|
suword(&arginfo->ps_nargvstr, argc);
|
|
|
|
/*
|
|
* Fill in argument portion of vector table.
|
|
*/
|
|
for (; argc > 0; --argc) {
|
|
suword(vectp++, (int)destp);
|
|
while (*stringp++ != 0)
|
|
destp++;
|
|
destp++;
|
|
}
|
|
|
|
/* a null vector table pointer seperates the argp's from the envp's */
|
|
suword(vectp++, 0);
|
|
|
|
suword(&arginfo->ps_envstr, (int)vectp);
|
|
suword(&arginfo->ps_nenvstr, envc);
|
|
|
|
/*
|
|
* Fill in environment portion of vector table.
|
|
*/
|
|
for (; envc > 0; --envc) {
|
|
suword(vectp++, (int)destp);
|
|
while (*stringp++ != 0)
|
|
destp++;
|
|
destp++;
|
|
}
|
|
|
|
/* end of vector table is a null pointer */
|
|
suword(vectp, 0);
|
|
|
|
return (stack_base);
|
|
}
|
|
|
|
/*
|
|
* Check permissions of file to execute.
|
|
* Return 0 for success or error code on failure.
|
|
*/
|
|
static int
|
|
exec_check_permissions(imgp)
|
|
struct image_params *imgp;
|
|
{
|
|
struct proc *p = imgp->proc;
|
|
struct vnode *vp = imgp->vp;
|
|
struct vattr *attr = imgp->attr;
|
|
int error;
|
|
|
|
/* Get file attributes */
|
|
error = VOP_GETATTR(vp, attr, p->p_ucred, p);
|
|
if (error)
|
|
return (error);
|
|
|
|
/*
|
|
* 1) Check if file execution is disabled for the filesystem that this
|
|
* file resides on.
|
|
* 2) Insure that at least one execute bit is on - otherwise root
|
|
* will always succeed, and we don't want to happen unless the
|
|
* file really is executable.
|
|
* 3) Insure that the file is a regular file.
|
|
*/
|
|
if ((vp->v_mount->mnt_flag & MNT_NOEXEC) ||
|
|
((attr->va_mode & 0111) == 0) ||
|
|
(attr->va_type != VREG)) {
|
|
return (EACCES);
|
|
}
|
|
|
|
/*
|
|
* Zero length files can't be exec'd
|
|
*/
|
|
if (attr->va_size == 0)
|
|
return (ENOEXEC);
|
|
|
|
/*
|
|
* Check for execute permission to file based on current credentials.
|
|
*/
|
|
error = VOP_ACCESS(vp, VEXEC, p->p_ucred, p);
|
|
if (error)
|
|
return (error);
|
|
|
|
/*
|
|
* Check number of open-for-writes on the file and deny execution
|
|
* if there are any.
|
|
*/
|
|
if (vp->v_writecount)
|
|
return (ETXTBSY);
|
|
|
|
/*
|
|
* Call filesystem specific open routine (which does nothing in the
|
|
* general case).
|
|
*/
|
|
error = VOP_OPEN(vp, FREAD, p->p_ucred, p);
|
|
if (error)
|
|
return (error);
|
|
|
|
return (0);
|
|
}
|