freebsd-skq/sys/fs/procfs/procfs_map.c
Konstantin Belousov 22a448c4d9 vm_map_lock_read() does not increment map->timestamp, so we should
compare map->timestamp with saved timestamp after map read lock is
reacquired, not with saved timestamp + 1. The only consequence of the +1
was unconditional lookup of the next map entry, though.

Tested by:	pho
Approved by:	des
MFC after:	2 weeks
2008-12-29 12:45:11 +00:00

241 lines
6.4 KiB
C

/*-
* 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.
* 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_status.c 8.3 (Berkeley) 2/17/94
*
* $FreeBSD$
*/
#include "opt_compat.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/lock.h>
#include <sys/filedesc.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/sbuf.h>
#ifdef COMPAT_IA32
#include <sys/sysent.h>
#endif
#include <sys/uio.h>
#include <sys/vnode.h>
#include <fs/pseudofs/pseudofs.h>
#include <fs/procfs/procfs.h>
#include <vm/vm.h>
#include <vm/vm_extern.h>
#include <vm/pmap.h>
#include <vm/vm_map.h>
#include <vm/vm_page.h>
#include <vm/vm_object.h>
#define MEBUFFERSIZE 256
/*
* The map entries can *almost* be read with programs like cat. However,
* large maps need special programs to read. It is not easy to implement
* a program that can sense the required size of the buffer, and then
* subsequently do a read with the appropriate size. This operation cannot
* be atomic. The best that we can do is to allow the program to do a read
* with an arbitrarily large buffer, and return as much as we can. We can
* return an error code if the buffer is too small (EFBIG), then the program
* can try a bigger buffer.
*/
int
procfs_doprocmap(PFS_FILL_ARGS)
{
struct vmspace *vm;
vm_map_t map;
vm_map_entry_t entry, tmp_entry;
struct vnode *vp;
char *fullpath, *freepath;
int error, vfslocked;
unsigned int last_timestamp;
#ifdef COMPAT_IA32
int wrap32 = 0;
#endif
PROC_LOCK(p);
error = p_candebug(td, p);
PROC_UNLOCK(p);
if (error)
return (error);
if (uio->uio_rw != UIO_READ)
return (EOPNOTSUPP);
#ifdef COMPAT_IA32
if (curproc->p_sysent->sv_flags & SV_ILP32) {
if (!(p->p_sysent->sv_flags & SV_ILP32))
return (EOPNOTSUPP);
wrap32 = 1;
}
#endif
vm = vmspace_acquire_ref(p);
if (vm == NULL)
return (ESRCH);
map = &vm->vm_map;
vm_map_lock_read(map);
for (entry = map->header.next; entry != &map->header;
entry = entry->next) {
vm_object_t obj, tobj, lobj;
int ref_count, shadow_count, flags;
vm_offset_t e_start, e_end, addr;
int resident, privateresident;
char *type;
vm_eflags_t e_eflags;
vm_prot_t e_prot;
if (entry->eflags & MAP_ENTRY_IS_SUB_MAP)
continue;
e_eflags = entry->eflags;
e_prot = entry->protection;
e_start = entry->start;
e_end = entry->end;
privateresident = 0;
obj = entry->object.vm_object;
if (obj != NULL) {
VM_OBJECT_LOCK(obj);
if (obj->shadow_count == 1)
privateresident = obj->resident_page_count;
}
resident = 0;
addr = entry->start;
while (addr < entry->end) {
if (pmap_extract(map->pmap, addr))
resident++;
addr += PAGE_SIZE;
}
for (lobj = tobj = obj; tobj; tobj = tobj->backing_object) {
if (tobj != obj)
VM_OBJECT_LOCK(tobj);
if (lobj != obj)
VM_OBJECT_UNLOCK(lobj);
lobj = tobj;
}
last_timestamp = map->timestamp;
vm_map_unlock_read(map);
freepath = NULL;
fullpath = "-";
if (lobj) {
switch (lobj->type) {
default:
case OBJT_DEFAULT:
type = "default";
vp = NULL;
break;
case OBJT_VNODE:
type = "vnode";
vp = lobj->handle;
vref(vp);
break;
case OBJT_SWAP:
type = "swap";
vp = NULL;
break;
case OBJT_DEVICE:
type = "device";
vp = NULL;
break;
}
if (lobj != obj)
VM_OBJECT_UNLOCK(lobj);
flags = obj->flags;
ref_count = obj->ref_count;
shadow_count = obj->shadow_count;
VM_OBJECT_UNLOCK(obj);
if (vp != NULL) {
vn_fullpath(td, vp, &fullpath, &freepath);
vfslocked = VFS_LOCK_GIANT(vp->v_mount);
vrele(vp);
VFS_UNLOCK_GIANT(vfslocked);
}
} else {
type = "none";
flags = 0;
ref_count = 0;
shadow_count = 0;
}
/*
* format:
* start, end, resident, private resident, cow, access, type.
*/
error = sbuf_printf(sb,
"0x%lx 0x%lx %d %d %p %s%s%s %d %d 0x%x %s %s %s %s\n",
(u_long)e_start, (u_long)e_end,
resident, privateresident,
#ifdef COMPAT_IA32
wrap32 ? NULL : obj, /* Hide 64 bit value */
#else
obj,
#endif
(e_prot & VM_PROT_READ)?"r":"-",
(e_prot & VM_PROT_WRITE)?"w":"-",
(e_prot & VM_PROT_EXECUTE)?"x":"-",
ref_count, shadow_count, flags,
(e_eflags & MAP_ENTRY_COW)?"COW":"NCOW",
(e_eflags & MAP_ENTRY_NEEDS_COPY)?"NC":"NNC",
type, fullpath);
if (freepath != NULL)
free(freepath, M_TEMP);
vm_map_lock_read(map);
if (error == -1) {
error = 0;
break;
}
if (last_timestamp != map->timestamp) {
/*
* Look again for the entry because the map was
* modified while it was unlocked. Specifically,
* the entry may have been clipped, merged, or deleted.
*/
vm_map_lookup_entry(map, e_end - 1, &tmp_entry);
entry = tmp_entry;
}
}
vm_map_unlock_read(map);
vmspace_free(vm);
return (error);
}