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NetBSD/sys/kern/kern_exec.c

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/* $NetBSD: kern_exec.c,v 1.134 2000/12/22 22:58:59 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 "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/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>
/*
* 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;
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 __P((struct proc *));
#else
void syscall __P((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,
sigcode,
esigcode,
NULL,
NULL,
NULL,
#ifdef __HAVE_SYSCALL_INTERN
syscall_intern,
#else
syscall,
#endif
};
/*
* 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;
#ifdef LKM
static const struct emul * emul_search __P((const char *));
static void link_es __P((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) || (p->p_flag & P_TRACED))
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 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 > 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, i;
struct exec_package pack;
struct nameidata nid;
struct vattr attr;
struct ucred *cred = p->p_ucred;
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 = 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;
lockmgr(&exec_lock, LK_SHARED, NULL);
/* 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);
/* Now map address space */
vm = p->p_vmspace;
vm->vm_taddr = (char *) pack.ep_taddr;
vm->vm_tsize = btoc(pack.ep_tsize);
vm->vm_daddr = (char *) pack.ep_daddr;
vm->vm_dsize = btoc(pack.ep_dsize);
vm->vm_ssize = btoc(pack.ep_ssize);
vm->vm_maxsaddr = (char *) pack.ep_maxsaddr;
vm->vm_minsaddr = (char *) 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
if (error) {
if (i > 0)
printf("vmcmd[%d] = %#lx/%#lx @ %#lx\n", i-1,
vcp[-1].ev_addr, vcp[-1].ev_len,
vcp[-1].ev_offset);
printf("vmcmd[%d] = %#lx/%#lx @ %#lx\n", i,
vcp->ev_addr, vcp->ev_len, vcp->ev_offset);
}
#endif
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) {
#ifdef DEBUG
printf("execve: vmcmd %i failed: %d\n", i-1, error);
#endif
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 */
if (!(*pack.ep_es->es_copyargs)(&pack, &arginfo, stack, argp)) {
#ifdef DEBUG
printf("execve: copyargs failed\n");
#endif
goto exec_abort;
}
/* 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 (copyout(&arginfo, (char *)p->p_psstr, sizeof(arginfo))) {
#ifdef DEBUG
printf("execve: ps_strings copyout failed\n");
#endif
goto exec_abort;
}
/* copy out the process's signal trapoline code */
if (szsigcode) {
if (copyout((char *)pack.ep_es->es_emul->e_sigcode,
p->p_sigctx.ps_sigcode = (char *)p->p_psstr - szsigcode,
szsigcode)) {
#ifdef DEBUG
printf("execve: sig trampoline copyout failed\n");
#endif
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 and P_TRACED have already been used to disable s[ug]id.
*/
if (((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)){
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;
p_sugid(p);
} 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;
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);
/* setup new registers and do misc. setup. */
(*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;
#ifdef __HAVE_SYSCALL_INTERN
(*p->p_emul->e_syscall_intern)(p);
#endif
#ifdef KTRACE
if (KTRPOINT(p, KTR_EMUL))
ktremul(p);
#endif
lockmgr(&exec_lock, LK_RELEASE, NULL);
return (EJUSTRETURN);
bad:
/* 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:
lockmgr(&exec_lock, LK_RELEASE, NULL);
free(pack.ep_hdr, M_EXEC);
return error;
exec_abort:
lockmgr(&exec_lock, LK_RELEASE, NULL);
/*
* 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(0, SIGABRT));
exit1(p, -1);
/* NOTREACHED */
return 0;
}
void *
copyargs(struct exec_package *pack, struct ps_strings *arginfo,
void *stack, void *argp)
{
char **cpp = stack;
char *dp, *sp;
size_t len;
void *nullp = NULL;
long argc = arginfo->ps_nargvstr;
long envc = arginfo->ps_nenvstr;
#ifdef __sparc_v9__
/* XXX Temporary hack for argc format conversion. */
argc <<= 32;
#endif
if (copyout(&argc, cpp++, sizeof(argc)))
return NULL;
#ifdef __sparc_v9__
/* XXX Temporary hack for argc format conversion. */
argc >>= 32;
#endif
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 (copyout(&dp, cpp++, sizeof(dp)) ||
copyoutstr(sp, dp, ARG_MAX, &len))
return NULL;
if (copyout(&nullp, cpp++, sizeof(nullp)))
return NULL;
arginfo->ps_envstr = cpp; /* remember location of envp for later */
for (; --envc >= 0; sp += len, dp += len)
if (copyout(&dp, cpp++, sizeof(dp)) ||
copyoutstr(sp, dp, ARG_MAX, &len))
return NULL;
if (copyout(&nullp, cpp++, sizeof(nullp)))
return NULL;
return cpp;
}
#ifdef LKM
/*
* Find an emulation of given name in list of emulations.
*/
static const struct emul *
emul_search(name)
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(emul, ro_entry)
const struct emul *emul;
int ro_entry;
{
struct emul_entry *ee;
int 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(name)
const char *name;
{
struct emul_entry *it;
int i, error = 0;
const struct proclist_desc *pd;
struct proc *ptmp;
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(esp, e_name)
struct execsw *esp;
const char *e_name;
{
struct exec_entry *it;
int 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(esp)
const struct execsw *esp;
{
struct exec_entry *it;
int 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(listp, esp)
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\n",
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 hold,
* i.e. via exec_{add|remove}().
*/
int
exec_init(init_boot)
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[]\n");
#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(init_boot)
int init_boot;
{
int i;
#ifdef DIAGNOSTIC
if (!init_boot)
panic("exec_init(): called with init_boot == 0");
#endif
/* do one-time initializations */
lockinit(&exec_lock, PWAIT, "execlck", 0, 0);
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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