freebsd-skq/sys/fs/procfs/procfs_map.c
vangyzen 597cee37df Provide vnode in memory map info for files on tmpfs
When providing memory map information to userland, populate the vnode pointer
for tmpfs files.  Set the memory mapping to appear as a vnode type, to match
FreeBSD 9 behavior.

This fixes the use of tmpfs files with the dtrace pid provider,
procstat -v, procfs, linprocfs, pmc (pmcstat), and ptrace (PT_VM_ENTRY).

Submitted by:   Eric Badger <eric@badgerio.us> (initial revision)
Obtained from:  Dell Inc.
PR:             198431
MFC after:      2 weeks
Reviewed by:    jhb
Approved by:    kib (mentor)
2015-06-02 18:37:04 +00:00

251 lines
6.7 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/proc.h>
#include <sys/resourcevar.h>
#include <sys/rwlock.h>
#include <sys/sbuf.h>
#ifdef COMPAT_FREEBSD32
#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;
struct ucred *cred;
int error;
unsigned int last_timestamp;
#ifdef COMPAT_FREEBSD32
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_FREEBSD32
if (SV_CURPROC_FLAG(SV_ILP32)) {
if (!(SV_PROC_FLAG(p, 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_RLOCK(obj);
if (obj->shadow_count == 1)
privateresident = obj->resident_page_count;
}
cred = (entry->cred) ? entry->cred : (obj ? obj->cred : NULL);
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_RLOCK(tobj);
if (lobj != obj)
VM_OBJECT_RUNLOCK(lobj);
lobj = tobj;
}
last_timestamp = map->timestamp;
vm_map_unlock_read(map);
freepath = NULL;
fullpath = "-";
if (lobj) {
vp = NULL;
switch (lobj->type) {
default:
case OBJT_DEFAULT:
type = "default";
break;
case OBJT_VNODE:
type = "vnode";
vp = lobj->handle;
vref(vp);
break;
case OBJT_SWAP:
if ((lobj->flags & OBJ_TMPFS_NODE) != 0) {
type = "vnode";
if ((lobj->flags & OBJ_TMPFS) != 0) {
vp = lobj->un_pager.swp.swp_tmpfs;
vref(vp);
}
} else {
type = "swap";
}
break;
case OBJT_SG:
case OBJT_DEVICE:
type = "device";
break;
}
if (lobj != obj)
VM_OBJECT_RUNLOCK(lobj);
flags = obj->flags;
ref_count = obj->ref_count;
shadow_count = obj->shadow_count;
VM_OBJECT_RUNLOCK(obj);
if (vp != NULL) {
vn_fullpath(td, vp, &fullpath, &freepath);
vrele(vp);
}
} else {
type = "none";
flags = 0;
ref_count = 0;
shadow_count = 0;
}
/*
* format:
* start, end, resident, private resident, cow, access, type,
* charged, charged uid.
*/
error = sbuf_printf(sb,
"0x%lx 0x%lx %d %d %p %s%s%s %d %d 0x%x %s %s %s %s %s %d\n",
(u_long)e_start, (u_long)e_end,
resident, privateresident,
#ifdef COMPAT_FREEBSD32
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,
cred ? "CH":"NCH", cred ? cred->cr_ruid : -1);
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);
}