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e0cc03a09b
NetBSD/sys/kern/kern_exec.c
jdolecek e0cc03a09b merge kqueue branch into -current 
kqueue provides a stateful and efficient event notification framework
currently supported events include socket, file, directory, fifo,
pipe, tty and device changes, and monitoring of processes and signals

kqueue is supported by all writable filesystems in NetBSD tree
(with exception of Coda) and all device drivers supporting poll(2)

based on work done by Jonathan Lemon for FreeBSD
initial NetBSD port done by Luke Mewburn and Jason Thorpe
2002-10-23 09:10:23 +00:00

1169 lines
28 KiB
C
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/* $NetBSD: kern_exec.c,v 1.159 2002/10/23 09:14:15 jdolecek Exp $ */
/*-
* Copyright (C) 1993, 1994, 1996 Christopher G. Demetriou
* Copyright (C) 1992 Wolfgang Solfrank.
* Copyright (C) 1992 TooLs GmbH.
* 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by TooLs GmbH.
* 4. The name of TooLs GmbH may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``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 TOOLS GMBH 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.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: kern_exec.c,v 1.159 2002/10/23 09:14:15 jdolecek Exp $");
#include "opt_ktrace.h"
#include "opt_syscall_debug.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/filedesc.h>
#include <sys/kernel.h>
#include <sys/proc.h>
#include <sys/mount.h>
#include <sys/malloc.h>
#include <sys/namei.h>
#include <sys/vnode.h>
#include <sys/file.h>
#include <sys/acct.h>
#include <sys/exec.h>
#include <sys/ktrace.h>
#include <sys/resourcevar.h>
#include <sys/wait.h>
#include <sys/mman.h>
#include <sys/ras.h>
#include <sys/signalvar.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <sys/syscallargs.h>
#include <uvm/uvm_extern.h>
#include <machine/cpu.h>
#include <machine/reg.h>
#ifdef DEBUG_EXEC
#define DPRINTF(a) uprintf a
#else
#define DPRINTF(a)
#endif /* DEBUG_EXEC */
/*
* Exec function switch:
*
* Note that each makecmds function is responsible for loading the
* exec package with the necessary functions for any exec-type-specific
* handling.
*
* Functions for specific exec types should be defined in their own
* header file.
*/
extern const struct execsw execsw_builtin[];
extern int nexecs_builtin;
static const struct execsw **execsw = NULL;
static int nexecs;
u_int exec_maxhdrsz; /* must not be static - netbsd32 needs it */
#ifdef LKM
/* list of supported emulations */
static
LIST_HEAD(emlist_head, emul_entry) el_head = LIST_HEAD_INITIALIZER(el_head);
struct emul_entry {
LIST_ENTRY(emul_entry) el_list;
const struct emul *el_emul;
int ro_entry;
};
/* list of dynamically loaded execsw entries */
static
LIST_HEAD(execlist_head, exec_entry) ex_head = LIST_HEAD_INITIALIZER(ex_head);
struct exec_entry {
LIST_ENTRY(exec_entry) ex_list;
const struct execsw *es;
};
/* structure used for building execw[] */
struct execsw_entry {
struct execsw_entry *next;
const struct execsw *es;
};
#endif /* LKM */
/* NetBSD emul struct */
extern char sigcode[], esigcode[];
#ifdef SYSCALL_DEBUG
extern const char * const syscallnames[];
#endif
#ifdef __HAVE_SYSCALL_INTERN
void syscall_intern(struct proc *);
#else
void syscall(void);
#endif
const struct emul emul_netbsd = {
"netbsd",
NULL, /* emulation path */
#ifndef __HAVE_MINIMAL_EMUL
EMUL_HAS_SYS___syscall,
NULL,
SYS_syscall,
SYS_MAXSYSCALL,
#endif
sysent,
#ifdef SYSCALL_DEBUG
syscallnames,
#else
NULL,
#endif
sendsig,
trapsignal,
sigcode,
esigcode,
setregs,
NULL,
NULL,
NULL,
#ifdef __HAVE_SYSCALL_INTERN
syscall_intern,
#else
syscall,
#endif
NULL,
NULL,
};
#ifdef LKM
/*
* Exec lock. Used to control access to execsw[] structures.
* This must not be static so that netbsd32 can access it, too.
*/
struct lock exec_lock;
static void link_es(struct execsw_entry **, const struct execsw *);
#endif /* LKM */
/*
* check exec:
* given an "executable" described in the exec package's namei info,
* see what we can do with it.
*
* ON ENTRY:
* exec package with appropriate namei info
* proc pointer of exec'ing proc
* NO SELF-LOCKED VNODES
*
* ON EXIT:
* error: nothing held, etc. exec header still allocated.
* ok: filled exec package, executable's vnode (unlocked).
*
* EXEC SWITCH ENTRY:
* Locked vnode to check, exec package, proc.
*
* EXEC SWITCH EXIT:
* ok: return 0, filled exec package, executable's vnode (unlocked).
* error: destructive:
* everything deallocated execept exec header.
* non-destructive:
* error code, executable's vnode (unlocked),
* exec header unmodified.
*/
int
check_exec(struct proc *p, struct exec_package *epp)
{
int error, i;
struct vnode *vp;
struct nameidata *ndp;
size_t resid;
ndp = epp->ep_ndp;
ndp->ni_cnd.cn_nameiop = LOOKUP;
ndp->ni_cnd.cn_flags = FOLLOW | LOCKLEAF | SAVENAME;
/* first get the vnode */
if ((error = namei(ndp)) != 0)
return error;
epp->ep_vp = vp = ndp->ni_vp;
/* check access and type */
if (vp->v_type != VREG) {
error = EACCES;
goto bad1;
}
if ((error = VOP_ACCESS(vp, VEXEC, p->p_ucred, p)) != 0)
goto bad1;
/* get attributes */
if ((error = VOP_GETATTR(vp, epp->ep_vap, p->p_ucred, p)) != 0)
goto bad1;
/* Check mount point */
if (vp->v_mount->mnt_flag & MNT_NOEXEC) {
error = EACCES;
goto bad1;
}
if (vp->v_mount->mnt_flag & MNT_NOSUID)
epp->ep_vap->va_mode &= ~(S_ISUID | S_ISGID);
/* try to open it */
if ((error = VOP_OPEN(vp, FREAD, p->p_ucred, p)) != 0)
goto bad1;
/* unlock vp, since we need it unlocked from here on out. */
VOP_UNLOCK(vp, 0);
/* now we have the file, get the exec header */
uvn_attach(vp, VM_PROT_READ);
error = vn_rdwr(UIO_READ, vp, epp->ep_hdr, epp->ep_hdrlen, 0,
UIO_SYSSPACE, 0, p->p_ucred, &resid, p);
if (error)
goto bad2;
epp->ep_hdrvalid = epp->ep_hdrlen - resid;
/*
* Set up default address space limits. Can be overridden
* by individual exec packages.
*
* XXX probably shoul be all done in the exec pakages.
*/
epp->ep_vm_minaddr = VM_MIN_ADDRESS;
epp->ep_vm_maxaddr = VM_MAXUSER_ADDRESS;
/*
* set up the vmcmds for creation of the process
* address space
*/
error = ENOEXEC;
for (i = 0; i < nexecs && error != 0; i++) {
int newerror;
epp->ep_esch = execsw[i];
newerror = (*execsw[i]->es_check)(p, epp);
/* make sure the first "interesting" error code is saved. */
if (!newerror || error == ENOEXEC)
error = newerror;
/* if es_check call was successful, update epp->ep_es */
if (!newerror && (epp->ep_flags & EXEC_HASES) == 0)
epp->ep_es = execsw[i];
if (epp->ep_flags & EXEC_DESTR && error != 0)
return error;
}
if (!error) {
/* check that entry point is sane */
if (epp->ep_entry > VM_MAXUSER_ADDRESS)
error = ENOEXEC;
/* check limits */
if ((epp->ep_tsize > MAXTSIZ) ||
(epp->ep_dsize >
(u_quad_t)p->p_rlimit[RLIMIT_DATA].rlim_cur))
error = ENOMEM;
if (!error)
return (0);
}
/*
* free any vmspace-creation commands,
* and release their references
*/
kill_vmcmds(&epp->ep_vmcmds);
bad2:
/*
* close and release the vnode, restore the old one, free the
* pathname buf, and punt.
*/
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
VOP_CLOSE(vp, FREAD, p->p_ucred, p);
vput(vp);
PNBUF_PUT(ndp->ni_cnd.cn_pnbuf);
return error;
bad1:
/*
* free the namei pathname buffer, and put the vnode
* (which we don't yet have open).
*/
vput(vp); /* was still locked */
PNBUF_PUT(ndp->ni_cnd.cn_pnbuf);
return error;
}
/*
* exec system call
*/
/* ARGSUSED */
int
sys_execve(struct proc *p, void *v, register_t *retval)
{
struct sys_execve_args /* {
syscallarg(const char *) path;
syscallarg(char * const *) argp;
syscallarg(char * const *) envp;
} */ *uap = v;
int error;
u_int i;
struct exec_package pack;
struct nameidata nid;
struct vattr attr;
struct ucred *cred;
char *argp;
char * const *cpp;
char *dp, *sp;
long argc, envc;
size_t len;
char *stack;
struct ps_strings arginfo;
struct vmspace *vm;
char **tmpfap;
int szsigcode;
struct exec_vmcmd *base_vcp;
/*
* Lock the process and set the P_INEXEC flag to indicate that
* it should be left alone until we're done here. This is
* necessary to avoid race conditions - e.g. in ptrace() -
* that might allow a local user to illicitly obtain elevated
* privileges.
*/
p->p_flag |= P_INEXEC;
cred = p->p_ucred;
base_vcp = NULL;
/*
* Init the namei data to point the file user's program name.
* This is done here rather than in check_exec(), so that it's
* possible to override this settings if any of makecmd/probe
* functions call check_exec() recursively - for example,
* see exec_script_makecmds().
*/
NDINIT(&nid, LOOKUP, NOFOLLOW, UIO_USERSPACE, SCARG(uap, path), p);
/*
* initialize the fields of the exec package.
*/
pack.ep_name = SCARG(uap, path);
pack.ep_hdr = malloc(exec_maxhdrsz, M_EXEC, M_WAITOK);
pack.ep_hdrlen = exec_maxhdrsz;
pack.ep_hdrvalid = 0;
pack.ep_ndp = &nid;
pack.ep_emul_arg = NULL;
pack.ep_vmcmds.evs_cnt = 0;
pack.ep_vmcmds.evs_used = 0;
pack.ep_vap = &attr;
pack.ep_flags = 0;
#ifdef LKM
lockmgr(&exec_lock, LK_SHARED, NULL);
#endif
/* see if we can run it. */
if ((error = check_exec(p, &pack)) != 0)
goto freehdr;
/* XXX -- THE FOLLOWING SECTION NEEDS MAJOR CLEANUP */
/* allocate an argument buffer */
argp = (char *) uvm_km_valloc_wait(exec_map, NCARGS);
#ifdef DIAGNOSTIC
if (argp == (vaddr_t) 0)
panic("execve: argp == NULL");
#endif
dp = argp;
argc = 0;
/* copy the fake args list, if there's one, freeing it as we go */
if (pack.ep_flags & EXEC_HASARGL) {
tmpfap = pack.ep_fa;
while (*tmpfap != NULL) {
char *cp;
cp = *tmpfap;
while (*cp)
*dp++ = *cp++;
dp++;
FREE(*tmpfap, M_EXEC);
tmpfap++; argc++;
}
FREE(pack.ep_fa, M_EXEC);
pack.ep_flags &= ~EXEC_HASARGL;
}
/* Now get argv & environment */
if (!(cpp = SCARG(uap, argp))) {
error = EINVAL;
goto bad;
}
if (pack.ep_flags & EXEC_SKIPARG)
cpp++;
while (1) {
len = argp + ARG_MAX - dp;
if ((error = copyin(cpp, &sp, sizeof(sp))) != 0)
goto bad;
if (!sp)
break;
if ((error = copyinstr(sp, dp, len, &len)) != 0) {
if (error == ENAMETOOLONG)
error = E2BIG;
goto bad;
}
dp += len;
cpp++;
argc++;
}
envc = 0;
/* environment need not be there */
if ((cpp = SCARG(uap, envp)) != NULL ) {
while (1) {
len = argp + ARG_MAX - dp;
if ((error = copyin(cpp, &sp, sizeof(sp))) != 0)
goto bad;
if (!sp)
break;
if ((error = copyinstr(sp, dp, len, &len)) != 0) {
if (error == ENAMETOOLONG)
error = E2BIG;
goto bad;
}
dp += len;
cpp++;
envc++;
}
}
dp = (char *) ALIGN(dp);
szsigcode = pack.ep_es->es_emul->e_esigcode -
pack.ep_es->es_emul->e_sigcode;
/* Now check if args & environ fit into new stack */
if (pack.ep_flags & EXEC_32)
len = ((argc + envc + 2 + pack.ep_es->es_arglen) *
sizeof(int) + sizeof(int) + dp + STACKGAPLEN +
szsigcode + sizeof(struct ps_strings)) - argp;
else
len = ((argc + envc + 2 + pack.ep_es->es_arglen) *
sizeof(char *) + sizeof(int) + dp + STACKGAPLEN +
szsigcode + sizeof(struct ps_strings)) - argp;
len = ALIGN(len); /* make the stack "safely" aligned */
if (len > pack.ep_ssize) { /* in effect, compare to initial limit */
error = ENOMEM;
goto bad;
}
/* adjust "active stack depth" for process VSZ */
pack.ep_ssize = len; /* maybe should go elsewhere, but... */
/*
* Do whatever is necessary to prepare the address space
* for remapping. Note that this might replace the current
* vmspace with another!
*/
uvmspace_exec(p, pack.ep_vm_minaddr, pack.ep_vm_maxaddr);
/* Now map address space */
vm = p->p_vmspace;
vm->vm_taddr = (caddr_t) pack.ep_taddr;
vm->vm_tsize = btoc(pack.ep_tsize);
vm->vm_daddr = (caddr_t) pack.ep_daddr;
vm->vm_dsize = btoc(pack.ep_dsize);
vm->vm_ssize = btoc(pack.ep_ssize);
vm->vm_maxsaddr = (caddr_t) pack.ep_maxsaddr;
vm->vm_minsaddr = (caddr_t) pack.ep_minsaddr;
/* create the new process's VM space by running the vmcmds */
#ifdef DIAGNOSTIC
if (pack.ep_vmcmds.evs_used == 0)
panic("execve: no vmcmds");
#endif
for (i = 0; i < pack.ep_vmcmds.evs_used && !error; i++) {
struct exec_vmcmd *vcp;
vcp = &pack.ep_vmcmds.evs_cmds[i];
if (vcp->ev_flags & VMCMD_RELATIVE) {
#ifdef DIAGNOSTIC
if (base_vcp == NULL)
panic("execve: relative vmcmd with no base");
if (vcp->ev_flags & VMCMD_BASE)
panic("execve: illegal base & relative vmcmd");
#endif
vcp->ev_addr += base_vcp->ev_addr;
}
error = (*vcp->ev_proc)(p, vcp);
#ifdef DEBUG_EXEC
if (error) {
int j;
struct exec_vmcmd *vp = &pack.ep_vmcmds.evs_cmds[0];
for (j = 0; j <= i; j++)
uprintf(
"vmcmd[%d] = %#lx/%#lx fd@%#lx prot=0%o flags=%d\n",
j, vp[j].ev_addr, vp[j].ev_len,
vp[j].ev_offset, vp[j].ev_prot,
vp[j].ev_flags);
}
#endif /* DEBUG_EXEC */
if (vcp->ev_flags & VMCMD_BASE)
base_vcp = vcp;
}
/* free the vmspace-creation commands, and release their references */
kill_vmcmds(&pack.ep_vmcmds);
/* if an error happened, deallocate and punt */
if (error) {
DPRINTF(("execve: vmcmd %i failed: %d\n", i - 1, error));
goto exec_abort;
}
/* remember information about the process */
arginfo.ps_nargvstr = argc;
arginfo.ps_nenvstr = envc;
stack = (char *) (vm->vm_minsaddr - len);
/* Now copy argc, args & environ to new stack */
error = (*pack.ep_es->es_copyargs)(p, &pack, &arginfo, &stack, argp);
if (error) {
DPRINTF(("execve: copyargs failed %d\n", error));
goto exec_abort;
}
/* Move the stack back to original point */
stack = (char *) (vm->vm_minsaddr - len);
/* fill process ps_strings info */
p->p_psstr = (struct ps_strings *)(vm->vm_minsaddr
- sizeof(struct ps_strings));
p->p_psargv = offsetof(struct ps_strings, ps_argvstr);
p->p_psnargv = offsetof(struct ps_strings, ps_nargvstr);
p->p_psenv = offsetof(struct ps_strings, ps_envstr);
p->p_psnenv = offsetof(struct ps_strings, ps_nenvstr);
/* copy out the process's ps_strings structure */
if ((error = copyout(&arginfo, (char *)p->p_psstr,
sizeof(arginfo))) != 0) {
DPRINTF(("execve: ps_strings copyout %p->%p size %ld failed\n",
&arginfo, (char *)p->p_psstr, (long)sizeof(arginfo)));
goto exec_abort;
}
/* copy out the process's signal trampoline code */
if (szsigcode) {
if ((error = copyout((char *)pack.ep_es->es_emul->e_sigcode,
p->p_sigctx.ps_sigcode = (char *)p->p_psstr - szsigcode,
szsigcode)) != 0) {
DPRINTF(("execve: sig trampoline copyout failed\n"));
goto exec_abort;
}
#ifdef PMAP_NEED_PROCWR
/* This is code. Let the pmap do what is needed. */
pmap_procwr(p, (vaddr_t)p->p_sigctx.ps_sigcode, szsigcode);
#endif
}
stopprofclock(p); /* stop profiling */
fdcloseexec(p); /* handle close on exec */
execsigs(p); /* reset catched signals */
p->p_ctxlink = NULL; /* reset ucontext link */
/* set command name & other accounting info */
len = min(nid.ni_cnd.cn_namelen, MAXCOMLEN);
memcpy(p->p_comm, nid.ni_cnd.cn_nameptr, len);
p->p_comm[len] = 0;
p->p_acflag &= ~AFORK;
/* record proc's vnode, for use by procfs and others */
if (p->p_textvp)
vrele(p->p_textvp);
VREF(pack.ep_vp);
p->p_textvp = pack.ep_vp;
p->p_flag |= P_EXEC;
if (p->p_flag & P_PPWAIT) {
p->p_flag &= ~P_PPWAIT;
wakeup((caddr_t) p->p_pptr);
}
/*
* deal with set[ug]id.
* MNT_NOSUID has already been used to disable s[ug]id.
*/
if ((p->p_flag & P_TRACED) == 0 &&
(((attr.va_mode & S_ISUID) != 0 &&
p->p_ucred->cr_uid != attr.va_uid) ||
((attr.va_mode & S_ISGID) != 0 &&
p->p_ucred->cr_gid != attr.va_gid))) {
/*
* Mark the process as SUGID before we do
* anything that might block.
*/
p_sugid(p);
/* Make sure file descriptors 0..2 are in use. */
if ((error = fdcheckstd(p)) != 0)
goto exec_abort;
p->p_ucred = crcopy(cred);
#ifdef KTRACE
/*
* If process is being ktraced, turn off - unless
* root set it.
*/
if (p->p_tracep && !(p->p_traceflag & KTRFAC_ROOT))
ktrderef(p);
#endif
if (attr.va_mode & S_ISUID)
p->p_ucred->cr_uid = attr.va_uid;
if (attr.va_mode & S_ISGID)
p->p_ucred->cr_gid = attr.va_gid;
} else
p->p_flag &= ~P_SUGID;
p->p_cred->p_svuid = p->p_ucred->cr_uid;
p->p_cred->p_svgid = p->p_ucred->cr_gid;
#if defined(__HAVE_RAS)
/*
* Remove all RASs from the address space.
*/
ras_purgeall(p);
#endif
doexechooks(p);
uvm_km_free_wakeup(exec_map, (vaddr_t) argp, NCARGS);
PNBUF_PUT(nid.ni_cnd.cn_pnbuf);
vn_lock(pack.ep_vp, LK_EXCLUSIVE | LK_RETRY);
VOP_CLOSE(pack.ep_vp, FREAD, cred, p);
vput(pack.ep_vp);
/* notify others that we exec'd */
KNOTE(&p->p_klist, NOTE_EXEC);
/* setup new registers and do misc. setup. */
(*pack.ep_es->es_emul->e_setregs)(p, &pack, (u_long) stack);
if (pack.ep_es->es_setregs)
(*pack.ep_es->es_setregs)(p, &pack, (u_long) stack);
if (p->p_flag & P_TRACED)
psignal(p, SIGTRAP);
free(pack.ep_hdr, M_EXEC);
/*
* Call emulation specific exec hook. This can setup setup per-process
* p->p_emuldata or do any other per-process stuff an emulation needs.
*
* If we are executing process of different emulation than the
* original forked process, call e_proc_exit() of the old emulation
* first, then e_proc_exec() of new emulation. If the emulation is
* same, the exec hook code should deallocate any old emulation
* resources held previously by this process.
*/
if (p->p_emul && p->p_emul->e_proc_exit
&& p->p_emul != pack.ep_es->es_emul)
(*p->p_emul->e_proc_exit)(p);
/*
* Call exec hook. Emulation code may NOT store reference to anything
* from &pack.
*/
if (pack.ep_es->es_emul->e_proc_exec)
(*pack.ep_es->es_emul->e_proc_exec)(p, &pack);
/* update p_emul, the old value is no longer needed */
p->p_emul = pack.ep_es->es_emul;
/* ...and the same for p_execsw */
p->p_execsw = pack.ep_es;
#ifdef __HAVE_SYSCALL_INTERN
(*p->p_emul->e_syscall_intern)(p);
#endif
#ifdef KTRACE
if (KTRPOINT(p, KTR_EMUL))
ktremul(p);
#endif
#ifdef LKM
lockmgr(&exec_lock, LK_RELEASE, NULL);
#endif
p->p_flag &= ~P_INEXEC;
return (EJUSTRETURN);
bad:
p->p_flag &= ~P_INEXEC;
/* free the vmspace-creation commands, and release their references */
kill_vmcmds(&pack.ep_vmcmds);
/* kill any opened file descriptor, if necessary */
if (pack.ep_flags & EXEC_HASFD) {
pack.ep_flags &= ~EXEC_HASFD;
(void) fdrelease(p, pack.ep_fd);
}
/* close and put the exec'd file */
vn_lock(pack.ep_vp, LK_EXCLUSIVE | LK_RETRY);
VOP_CLOSE(pack.ep_vp, FREAD, cred, p);
vput(pack.ep_vp);
PNBUF_PUT(nid.ni_cnd.cn_pnbuf);
uvm_km_free_wakeup(exec_map, (vaddr_t) argp, NCARGS);
freehdr:
p->p_flag &= ~P_INEXEC;
#ifdef LKM
lockmgr(&exec_lock, LK_RELEASE, NULL);
#endif
free(pack.ep_hdr, M_EXEC);
return error;
exec_abort:
p->p_flag &= ~P_INEXEC;
#ifdef LKM
lockmgr(&exec_lock, LK_RELEASE, NULL);
#endif
/*
* the old process doesn't exist anymore. exit gracefully.
* get rid of the (new) address space we have created, if any, get rid
* of our namei data and vnode, and exit noting failure
*/
uvm_deallocate(&vm->vm_map, VM_MIN_ADDRESS,
VM_MAXUSER_ADDRESS - VM_MIN_ADDRESS);
if (pack.ep_emul_arg)
FREE(pack.ep_emul_arg, M_TEMP);
PNBUF_PUT(nid.ni_cnd.cn_pnbuf);
vn_lock(pack.ep_vp, LK_EXCLUSIVE | LK_RETRY);
VOP_CLOSE(pack.ep_vp, FREAD, cred, p);
vput(pack.ep_vp);
uvm_km_free_wakeup(exec_map, (vaddr_t) argp, NCARGS);
free(pack.ep_hdr, M_EXEC);
exit1(p, W_EXITCODE(error, SIGABRT));
/* NOTREACHED */
return 0;
}
int
copyargs(struct proc *p, struct exec_package *pack, struct ps_strings *arginfo,
char **stackp, void *argp)
{
char **cpp, *dp, *sp;
size_t len;
void *nullp;
long argc, envc;
int error;
cpp = (char **)*stackp;
nullp = NULL;
argc = arginfo->ps_nargvstr;
envc = arginfo->ps_nenvstr;
if ((error = copyout(&argc, cpp++, sizeof(argc))) != 0)
return error;
dp = (char *) (cpp + argc + envc + 2 + pack->ep_es->es_arglen);
sp = argp;
/* XXX don't copy them out, remap them! */
arginfo->ps_argvstr = cpp; /* remember location of argv for later */
for (; --argc >= 0; sp += len, dp += len)
if ((error = copyout(&dp, cpp++, sizeof(dp))) != 0 ||
(error = copyoutstr(sp, dp, ARG_MAX, &len)) != 0)
return error;
if ((error = copyout(&nullp, cpp++, sizeof(nullp))) != 0)
return error;
arginfo->ps_envstr = cpp; /* remember location of envp for later */
for (; --envc >= 0; sp += len, dp += len)
if ((error = copyout(&dp, cpp++, sizeof(dp))) != 0 ||
(error = copyoutstr(sp, dp, ARG_MAX, &len)) != 0)
return error;
if ((error = copyout(&nullp, cpp++, sizeof(nullp))) != 0)
return error;
*stackp = (char *)cpp;
return 0;
}
#ifdef LKM
/*
* Find an emulation of given name in list of emulations.
* Needs to be called with the exec_lock held.
*/
const struct emul *
emul_search(const char *name)
{
struct emul_entry *it;
LIST_FOREACH(it, &el_head, el_list) {
if (strcmp(name, it->el_emul->e_name) == 0)
return it->el_emul;
}
return NULL;
}
/*
* Add an emulation to list, if it's not there already.
*/
int
emul_register(const struct emul *emul, int ro_entry)
{
struct emul_entry *ee;
int error;
error = 0;
lockmgr(&exec_lock, LK_SHARED, NULL);
if (emul_search(emul->e_name)) {
error = EEXIST;
goto out;
}
MALLOC(ee, struct emul_entry *, sizeof(struct emul_entry),
M_EXEC, M_WAITOK);
ee->el_emul = emul;
ee->ro_entry = ro_entry;
LIST_INSERT_HEAD(&el_head, ee, el_list);
out:
lockmgr(&exec_lock, LK_RELEASE, NULL);
return error;
}
/*
* Remove emulation with name 'name' from list of supported emulations.
*/
int
emul_unregister(const char *name)
{
const struct proclist_desc *pd;
struct emul_entry *it;
int i, error;
struct proc *ptmp;
error = 0;
lockmgr(&exec_lock, LK_SHARED, NULL);
LIST_FOREACH(it, &el_head, el_list) {
if (strcmp(it->el_emul->e_name, name) == 0)
break;
}
if (!it) {
error = ENOENT;
goto out;
}
if (it->ro_entry) {
error = EBUSY;
goto out;
}
/* test if any execw[] entry is still using this */
for(i=0; i < nexecs; i++) {
if (execsw[i]->es_emul == it->el_emul) {
error = EBUSY;
goto out;
}
}
/*
* Test if any process is running under this emulation - since
* emul_unregister() is running quite sendomly, it's better
* to do expensive check here than to use any locking.
*/
proclist_lock_read();
for (pd = proclists; pd->pd_list != NULL && !error; pd++) {
LIST_FOREACH(ptmp, pd->pd_list, p_list) {
if (ptmp->p_emul == it->el_emul) {
error = EBUSY;
break;
}
}
}
proclist_unlock_read();
if (error)
goto out;
/* entry is not used, remove it */
LIST_REMOVE(it, el_list);
FREE(it, M_EXEC);
out:
lockmgr(&exec_lock, LK_RELEASE, NULL);
return error;
}
/*
* Add execsw[] entry.
*/
int
exec_add(struct execsw *esp, const char *e_name)
{
struct exec_entry *it;
int error;
error = 0;
lockmgr(&exec_lock, LK_EXCLUSIVE, NULL);
if (!esp->es_emul) {
esp->es_emul = emul_search(e_name);
if (!esp->es_emul) {
error = ENOENT;
goto out;
}
}
LIST_FOREACH(it, &ex_head, ex_list) {
/* assume tuple (makecmds, probe_func, emulation) is unique */
if (it->es->es_check == esp->es_check
&& it->es->u.elf_probe_func == esp->u.elf_probe_func
&& it->es->es_emul == esp->es_emul) {
error = EEXIST;
goto out;
}
}
/* if we got here, the entry doesn't exist yet */
MALLOC(it, struct exec_entry *, sizeof(struct exec_entry),
M_EXEC, M_WAITOK);
it->es = esp;
LIST_INSERT_HEAD(&ex_head, it, ex_list);
/* update execsw[] */
exec_init(0);
out:
lockmgr(&exec_lock, LK_RELEASE, NULL);
return error;
}
/*
* Remove execsw[] entry.
*/
int
exec_remove(const struct execsw *esp)
{
struct exec_entry *it;
int error;
error = 0;
lockmgr(&exec_lock, LK_EXCLUSIVE, NULL);
LIST_FOREACH(it, &ex_head, ex_list) {
/* assume tuple (makecmds, probe_func, emulation) is unique */
if (it->es->es_check == esp->es_check
&& it->es->u.elf_probe_func == esp->u.elf_probe_func
&& it->es->es_emul == esp->es_emul)
break;
}
if (!it) {
error = ENOENT;
goto out;
}
/* remove item from list and free resources */
LIST_REMOVE(it, ex_list);
FREE(it, M_EXEC);
/* update execsw[] */
exec_init(0);
out:
lockmgr(&exec_lock, LK_RELEASE, NULL);
return error;
}
static void
link_es(struct execsw_entry **listp, const struct execsw *esp)
{
struct execsw_entry *et, *e1;
MALLOC(et, struct execsw_entry *, sizeof(struct execsw_entry),
M_TEMP, M_WAITOK);
et->next = NULL;
et->es = esp;
if (*listp == NULL) {
*listp = et;
return;
}
switch(et->es->es_prio) {
case EXECSW_PRIO_FIRST:
/* put new entry as the first */
et->next = *listp;
*listp = et;
break;
case EXECSW_PRIO_ANY:
/* put new entry after all *_FIRST and *_ANY entries */
for(e1 = *listp; e1->next
&& e1->next->es->es_prio != EXECSW_PRIO_LAST;
e1 = e1->next);
et->next = e1->next;
e1->next = et;
break;
case EXECSW_PRIO_LAST:
/* put new entry as the last one */
for(e1 = *listp; e1->next; e1 = e1->next);
e1->next = et;
break;
default:
#ifdef DIAGNOSTIC
panic("execw[] entry with unknown priority %d found",
et->es->es_prio);
#endif
break;
}
}
/*
* Initialize exec structures. If init_boot is true, also does necessary
* one-time initialization (it's called from main() that way).
* Once system is multiuser, this should be called with exec_lock held,
* i.e. via exec_{add|remove}().
*/
int
exec_init(int init_boot)
{
const struct execsw **new_es, * const *old_es;
struct execsw_entry *list, *e1;
struct exec_entry *e2;
int i, es_sz;
if (init_boot) {
/* do one-time initializations */
lockinit(&exec_lock, PWAIT, "execlck", 0, 0);
/* register compiled-in emulations */
for(i=0; i < nexecs_builtin; i++) {
if (execsw_builtin[i].es_emul)
emul_register(execsw_builtin[i].es_emul, 1);
}
#ifdef DIAGNOSTIC
if (i == 0)
panic("no emulations found in execsw_builtin[]");
#endif
}
/*
* Build execsw[] array from builtin entries and entries added
* at runtime.
*/
list = NULL;
for(i=0; i < nexecs_builtin; i++)
link_es(&list, &execsw_builtin[i]);
/* Add dynamically loaded entries */
es_sz = nexecs_builtin;
LIST_FOREACH(e2, &ex_head, ex_list) {
link_es(&list, e2->es);
es_sz++;
}
/*
* Now that we have sorted all execw entries, create new execsw[]
* and free no longer needed memory in the process.
*/
new_es = malloc(es_sz * sizeof(struct execsw *), M_EXEC, M_WAITOK);
for(i=0; list; i++) {
new_es[i] = list->es;
e1 = list->next;
FREE(list, M_TEMP);
list = e1;
}
/*
* New execsw[] array built, now replace old execsw[] and free
* used memory.
*/
old_es = execsw;
execsw = new_es;
nexecs = es_sz;
if (old_es)
free((void *)old_es, M_EXEC);
/*
* Figure out the maximum size of an exec header.
*/
exec_maxhdrsz = 0;
for (i = 0; i < nexecs; i++) {
if (execsw[i]->es_hdrsz > exec_maxhdrsz)
exec_maxhdrsz = execsw[i]->es_hdrsz;
}
return 0;
}
#endif
#ifndef LKM
/*
* Simplified exec_init() for kernels without LKMs. Only initialize
* exec_maxhdrsz and execsw[].
*/
int
exec_init(int init_boot)
{
int i;
#ifdef DIAGNOSTIC
if (!init_boot)
panic("exec_init(): called with init_boot == 0");
#endif
/* do one-time initializations */
nexecs = nexecs_builtin;
execsw = malloc(nexecs*sizeof(struct execsw *), M_EXEC, M_WAITOK);
/*
* Fill in execsw[] and figure out the maximum size of an exec header.
*/
exec_maxhdrsz = 0;
for(i=0; i < nexecs; i++) {
execsw[i] = &execsw_builtin[i];
if (execsw_builtin[i].es_hdrsz > exec_maxhdrsz)
exec_maxhdrsz = execsw_builtin[i].es_hdrsz;
}
return 0;
}
#endif /* !LKM */
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