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Instead of rolling our own jail number allocation procedure, use

Browse Source 
alloc_unr() to do it.

Submitted by:	Ed Schouten <ed 80386 nl>
PR:		kern/122270
MFC after:	1 month
This commit is contained in:
Xin LI 2008-04-11 21:31:15 +00:00
parent 03c7442d75
commit 31c50f53da
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=178124
2 changed files with 18 additions and 26 deletions
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42
sys/kern/kern_jail.c
View File

@ -24,6 +24,7 @@ __FBSDID("$FreeBSD$");
#include <sys/taskqueue.h>
#include <sys/fcntl.h>
#include <sys/jail.h>
#include <sys/limits.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/sx.h>
@ -79,11 +80,13 @@ SYSCTL_INT(_security_jail, OID_AUTO, mount_allowed, CTLFLAG_RW,
&jail_mount_allowed, 0,
"Processes in jail can mount/unmount jail-friendly file systems");
/* allprison, lastprid, and prisoncount are protected by allprison_lock. */
struct prisonlist allprison;
/* allprison and prisoncount are protected by allprison_lock. */
struct sx allprison_lock;
int lastprid = 0;
SX_SYSINIT(allprison_lock, &allprison_lock, "allprison");
struct prisonlist allprison = LIST_HEAD_INITIALIZER(allprison);
int prisoncount = 0;
/* Prison number allocation */
static struct unrhdr *prison_numpool;
/*
* List of jail services. Protected by allprison_lock.
@ -109,8 +112,7 @@ static void
init_prison(void *data __unused)
{
sx_init(&allprison_lock, "allprison");
LIST_INIT(&allprison);
prison_numpool = new_unrhdr(1, INT_MAX, NULL);
}
SYSINIT(prison, SI_SUB_INTRINSIC, SI_ORDER_ANY, init_prison, NULL);
@ -124,11 +126,11 @@ int
jail(struct thread *td, struct jail_args *uap)
{
struct nameidata nd;
struct prison *pr, *tpr;
struct prison *pr;
struct prison_service *psrv;
struct jail j;
struct jail_attach_args jaa;
int vfslocked, error, tryprid;
int vfslocked, error, prid;
error = copyin(uap->jail, &j, sizeof(j));
if (error)
@ -136,9 +138,15 @@ jail(struct thread *td, struct jail_args *uap)
if (j.version != 0)
return (EINVAL);
/* Allocate prison number */
prid = alloc_unr(prison_numpool);
if (prid == -1)
return (EAGAIN);
MALLOC(pr, struct prison *, sizeof(*pr), M_PRISON, M_WAITOK | M_ZERO);
mtx_init(&pr->pr_mtx, "jail mutex", NULL, MTX_DEF);
pr->pr_ref = 1;
pr->pr_id = jaa.jid = prid;
error = copyinstr(j.path, &pr->pr_path, sizeof(pr->pr_path), 0);
if (error)
goto e_killmtx;
@ -165,24 +173,8 @@ jail(struct thread *td, struct jail_args *uap)
M_PRISON, M_ZERO | M_WAITOK);
}
/* Determine next pr_id and add prison to allprison list. */
/* Add prison to allprison list. */
sx_xlock(&allprison_lock);
tryprid = lastprid + 1;
if (tryprid == JAIL_MAX)
tryprid = 1;
next:
LIST_FOREACH(tpr, &allprison, pr_list) {
if (tpr->pr_id == tryprid) {
tryprid++;
if (tryprid == JAIL_MAX) {
sx_xunlock(&allprison_lock);
error = EAGAIN;
goto e_dropvnref;
}
goto next;
}
}
pr->pr_id = jaa.jid = lastprid = tryprid;
LIST_INSERT_HEAD(&allprison, pr, pr_list);
prisoncount++;
sx_downgrade(&allprison_lock);
@ -214,6 +206,7 @@ jail(struct thread *td, struct jail_args *uap)
VFS_UNLOCK_GIANT(vfslocked);
e_killmtx:
mtx_destroy(&pr->pr_mtx);
free_unr(prison_numpool, pr->pr_id);
FREE(pr, M_PRISON);
return (error);
}
@ -347,6 +340,7 @@ prison_complete(void *context, int pending)
mtx_destroy(&pr->pr_mtx);
if (pr->pr_linux != NULL)
FREE(pr->pr_linux, M_PRISON);
free_unr(prison_numpool, pr->pr_id);
FREE(pr, M_PRISON);
}

2
sys/sys/jail.h
View File

@ -41,8 +41,6 @@ int jail_attach(int);
#include <sys/_mutex.h>
#include <sys/_task.h>
#define JAIL_MAX 999999
#ifdef MALLOC_DECLARE
MALLOC_DECLARE(M_PRISON);
#endif