freebsd-dev/sys/fs/procfs/procfs.c
Robert Watson 763bbd2f4f Slightly change the semantics of vnode labels for MAC: rather than
"refreshing" the label on the vnode before use, just get the label
right from inception.  For single-label file systems, set the label
in the generic VFS getnewvnode() code; for multi-label file systems,
leave the labeling up to the file system.  With UFS1/2, this means
reading the extended attribute during vfs_vget() as the inode is
pulled off disk, rather than hitting the extended attributes
frequently during operations later, improving performance.  This
also corrects sematics for shared vnode locks, which were not
previously present in the system.  This chances the cache
coherrency properties WRT out-of-band access to label data, but in
an acceptable form.  With UFS1, there is a small race condition
during automatic extended attribute start -- this is not present
with UFS2, and occurs because EAs aren't available at vnode
inception.  We'll introduce a work around for this shortly.

Approved by:	re
Obtained from:	TrustedBSD Project
Sponsored by:	DARPA, Network Associates Laboratories
2002-10-26 14:38:24 +00:00

201 lines
5.6 KiB
C

/*
* Copyright (c) 2001 Dag-Erling Smørgrav
* Copyright (c) 1993 Jan-Simon Pendry
* Copyright (c) 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Jan-Simon Pendry.
*
* 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 the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
*
* @(#)procfs_vfsops.c 8.7 (Berkeley) 5/10/95
*
* $FreeBSD$
*/
#include <sys/param.h>
#include <sys/queue.h>
#include <sys/exec.h>
#include <sys/lock.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/sbuf.h>
#include <sys/sysproto.h>
#include <sys/systm.h>
#include <sys/vnode.h>
#include <vm/vm.h>
#include <vm/pmap.h>
#include <vm/vm_param.h>
#include <fs/pseudofs/pseudofs.h>
#include <fs/procfs/procfs.h>
/*
* Filler function for proc/pid/self
*/
int
procfs_doprocfile(PFS_FILL_ARGS)
{
char *fullpath = "unknown";
char *freepath = NULL;
vn_fullpath(td, p->p_textvp, &fullpath, &freepath);
sbuf_printf(sb, "%s", fullpath);
if (freepath)
free(freepath, M_TEMP);
return (0);
}
/*
* Filler function for proc/curproc
*/
int
procfs_docurproc(PFS_FILL_ARGS)
{
sbuf_printf(sb, "%ld", (long)td->td_proc->p_pid);
return (0);
}
/*
* Adjust mode for some nodes that need it
*/
int
procfs_attr(PFS_ATTR_ARGS)
{
/* XXX inefficient, split into separate functions */
if (p->p_flag & P_SUGID)
vap->va_mode = 0;
else if (strcmp(pn->pn_name, "ctl") == 0 ||
strcmp(pn->pn_name, "note") == 0 ||
strcmp(pn->pn_name, "notepg") == 0)
vap->va_mode = 0200;
else if (strcmp(pn->pn_name, "mem") == 0 ||
strcmp(pn->pn_name, "regs") == 0 ||
strcmp(pn->pn_name, "dbregs") == 0 ||
strcmp(pn->pn_name, "fpregs") == 0)
vap->va_mode = 0600;
/* p is locked by caller */
PROC_LOCK_ASSERT(p, MA_OWNED);
vap->va_uid = p->p_ucred->cr_uid;
vap->va_gid = p->p_ucred->cr_gid;
return (0);
}
/*
* Visibility: some files only exist for non-system processes
* Non-static because linprocfs uses it.
*/
int
procfs_notsystem(PFS_VIS_ARGS)
{
return ((p->p_flag & P_SYSTEM) == 0);
}
/*
* Visibility: some files are only visible to process that can debug
* the target process.
*/
int
procfs_candebug(PFS_VIS_ARGS)
{
PROC_LOCK_ASSERT(p, MA_OWNED);
return ((p->p_flag & P_SYSTEM) == 0 &&
p_candebug(td, p) == 0);
}
/*
* Constructor
*/
static int
procfs_init(PFS_INIT_ARGS)
{
struct pfs_node *root;
struct pfs_node *dir;
struct pfs_node *node;
root = pi->pi_root;
pfs_create_link(root, "curproc", procfs_docurproc,
NULL, NULL, 0);
dir = pfs_create_dir(root, "pid",
procfs_attr, NULL, PFS_PROCDEP);
pfs_create_file(dir, "cmdline", procfs_doproccmdline,
NULL, NULL, PFS_RD);
pfs_create_file(dir, "ctl", procfs_doprocctl,
procfs_attr, NULL, PFS_WR);
pfs_create_file(dir, "dbregs", procfs_doprocdbregs,
procfs_attr, procfs_candebug, PFS_RDWR|PFS_RAW);
pfs_create_file(dir, "etype", procfs_doproctype,
NULL, NULL, PFS_RD);
pfs_create_file(dir, "fpregs", procfs_doprocfpregs,
procfs_attr, procfs_candebug, PFS_RDWR|PFS_RAW);
pfs_create_file(dir, "map", procfs_doprocmap,
NULL, procfs_notsystem, PFS_RD);
node = pfs_create_file(dir, "mem", procfs_doprocmem,
procfs_attr, procfs_candebug, PFS_RDWR|PFS_RAW);
node->pn_ioctl = procfs_ioctl;
node->pn_close = procfs_close;
pfs_create_file(dir, "note", procfs_doprocnote,
procfs_attr, procfs_candebug, PFS_WR);
pfs_create_file(dir, "notepg", procfs_doprocnote,
procfs_attr, procfs_candebug, PFS_WR);
pfs_create_file(dir, "regs", procfs_doprocregs,
procfs_attr, procfs_candebug, PFS_RDWR|PFS_RAW);
pfs_create_file(dir, "rlimit", procfs_doprocrlimit,
NULL, NULL, PFS_RD);
pfs_create_file(dir, "status", procfs_doprocstatus,
NULL, NULL, PFS_RD);
pfs_create_link(dir, "file", procfs_doprocfile,
NULL, procfs_notsystem, 0);
return (0);
}
/*
* Destructor
*/
static int
procfs_uninit(PFS_INIT_ARGS)
{
/* nothing to do, pseudofs will GC */
return (0);
}
PSEUDOFS(procfs, 1);