freebsd-dev/lib/libkvm/kvm_proc.c
Tor Egge a58930d8a9 Fill in parent process id when reading process information from a
memory dump. This fixes one of the problems noted in PR kern/3581.
1997-06-25 20:56:48 +00:00

723 lines
18 KiB
C

/*-
* Copyright (c) 1989, 1992, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software developed by the Computer Systems
* Engineering group at Lawrence Berkeley Laboratory under DARPA contract
* BG 91-66 and contributed to Berkeley.
*
* 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.
*/
#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)kvm_proc.c 8.3 (Berkeley) 9/23/93";
#endif /* LIBC_SCCS and not lint */
/*
* Proc traversal interface for kvm. ps and w are (probably) the exclusive
* users of this code, so we've factored it out into a separate module.
* Thus, we keep this grunge out of the other kvm applications (i.e.,
* most other applications are interested only in open/close/read/nlist).
*/
#include <sys/param.h>
#include <sys/user.h>
#include <sys/proc.h>
#include <sys/exec.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <sys/tty.h>
#include <sys/file.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <nlist.h>
#include <kvm.h>
#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/swap_pager.h>
#include <sys/sysctl.h>
#include <limits.h>
#include <memory.h>
#include <db.h>
#include <paths.h>
#include "kvm_private.h"
#if used
static char *
kvm_readswap(kd, p, va, cnt)
kvm_t *kd;
const struct proc *p;
u_long va;
u_long *cnt;
{
#ifdef __FreeBSD__
/* XXX Stubbed out, our vm system is differnet */
_kvm_err(kd, kd->program, "kvm_readswap not implemented");
return(0);
#endif /* __FreeBSD__ */
}
#endif
#define KREAD(kd, addr, obj) \
(kvm_read(kd, addr, (char *)(obj), sizeof(*obj)) != sizeof(*obj))
/*
* Read proc's from memory file into buffer bp, which has space to hold
* at most maxcnt procs.
*/
static int
kvm_proclist(kd, what, arg, p, bp, maxcnt)
kvm_t *kd;
int what, arg;
struct proc *p;
struct kinfo_proc *bp;
int maxcnt;
{
register int cnt = 0;
struct eproc eproc;
struct pgrp pgrp;
struct session sess;
struct tty tty;
struct proc proc;
struct proc pproc;
for (; cnt < maxcnt && p != NULL; p = proc.p_list.le_next) {
if (KREAD(kd, (u_long)p, &proc)) {
_kvm_err(kd, kd->program, "can't read proc at %x", p);
return (-1);
}
if (KREAD(kd, (u_long)proc.p_cred, &eproc.e_pcred) == 0)
(void)(KREAD(kd, (u_long)eproc.e_pcred.pc_ucred,
&eproc.e_ucred));
switch(what) {
case KERN_PROC_PID:
if (proc.p_pid != (pid_t)arg)
continue;
break;
case KERN_PROC_UID:
if (eproc.e_ucred.cr_uid != (uid_t)arg)
continue;
break;
case KERN_PROC_RUID:
if (eproc.e_pcred.p_ruid != (uid_t)arg)
continue;
break;
}
/*
* We're going to add another proc to the set. If this
* will overflow the buffer, assume the reason is because
* nprocs (or the proc list) is corrupt and declare an error.
*/
if (cnt >= maxcnt) {
_kvm_err(kd, kd->program, "nprocs corrupt");
return (-1);
}
/*
* gather eproc
*/
eproc.e_paddr = p;
if (KREAD(kd, (u_long)proc.p_pgrp, &pgrp)) {
_kvm_err(kd, kd->program, "can't read pgrp at %x",
proc.p_pgrp);
return (-1);
}
if (proc.p_oppid)
eproc.e_ppid = proc.p_oppid;
else if (proc.p_pptr) {
if (KREAD(kd, (u_long)proc.p_pptr, &pproc)) {
_kvm_err(kd, kd->program, "can't read pproc at %x",
proc.p_pptr);
return (-1);
}
eproc.e_ppid = pproc.p_pid;
} else
eproc.e_ppid = 0;
eproc.e_sess = pgrp.pg_session;
eproc.e_pgid = pgrp.pg_id;
eproc.e_jobc = pgrp.pg_jobc;
if (KREAD(kd, (u_long)pgrp.pg_session, &sess)) {
_kvm_err(kd, kd->program, "can't read session at %x",
pgrp.pg_session);
return (-1);
}
(void)memcpy(eproc.e_login, sess.s_login,
sizeof(eproc.e_login));
if ((proc.p_flag & P_CONTROLT) && sess.s_ttyp != NULL) {
if (KREAD(kd, (u_long)sess.s_ttyp, &tty)) {
_kvm_err(kd, kd->program,
"can't read tty at %x", sess.s_ttyp);
return (-1);
}
eproc.e_tdev = tty.t_dev;
eproc.e_tsess = tty.t_session;
if (tty.t_pgrp != NULL) {
if (KREAD(kd, (u_long)tty.t_pgrp, &pgrp)) {
_kvm_err(kd, kd->program,
"can't read tpgrp at &x",
tty.t_pgrp);
return (-1);
}
eproc.e_tpgid = pgrp.pg_id;
} else
eproc.e_tpgid = -1;
} else
eproc.e_tdev = NODEV;
eproc.e_flag = sess.s_ttyvp ? EPROC_CTTY : 0;
if (sess.s_leader == p)
eproc.e_flag |= EPROC_SLEADER;
if (proc.p_wmesg)
(void)kvm_read(kd, (u_long)proc.p_wmesg,
eproc.e_wmesg, WMESGLEN);
#ifdef sparc
(void)kvm_read(kd, (u_long)&proc.p_vmspace->vm_rssize,
(char *)&eproc.e_vm.vm_rssize,
sizeof(eproc.e_vm.vm_rssize));
(void)kvm_read(kd, (u_long)&proc.p_vmspace->vm_tsize,
(char *)&eproc.e_vm.vm_tsize,
3 * sizeof(eproc.e_vm.vm_rssize)); /* XXX */
#else
(void)kvm_read(kd, (u_long)proc.p_vmspace,
(char *)&eproc.e_vm, sizeof(eproc.e_vm));
#endif
eproc.e_xsize = eproc.e_xrssize = 0;
eproc.e_xccount = eproc.e_xswrss = 0;
switch (what) {
case KERN_PROC_PGRP:
if (eproc.e_pgid != (pid_t)arg)
continue;
break;
case KERN_PROC_TTY:
if ((proc.p_flag & P_CONTROLT) == 0 ||
eproc.e_tdev != (dev_t)arg)
continue;
break;
}
bcopy(&proc, &bp->kp_proc, sizeof(proc));
bcopy(&eproc, &bp->kp_eproc, sizeof(eproc));
++bp;
++cnt;
}
return (cnt);
}
/*
* Build proc info array by reading in proc list from a crash dump.
* Return number of procs read. maxcnt is the max we will read.
*/
static int
kvm_deadprocs(kd, what, arg, a_allproc, a_zombproc, maxcnt)
kvm_t *kd;
int what, arg;
u_long a_allproc;
u_long a_zombproc;
int maxcnt;
{
register struct kinfo_proc *bp = kd->procbase;
register int acnt, zcnt;
struct proc *p;
if (KREAD(kd, a_allproc, &p)) {
_kvm_err(kd, kd->program, "cannot read allproc");
return (-1);
}
acnt = kvm_proclist(kd, what, arg, p, bp, maxcnt);
if (acnt < 0)
return (acnt);
if (KREAD(kd, a_zombproc, &p)) {
_kvm_err(kd, kd->program, "cannot read zombproc");
return (-1);
}
zcnt = kvm_proclist(kd, what, arg, p, bp + acnt, maxcnt - acnt);
if (zcnt < 0)
zcnt = 0;
return (acnt + zcnt);
}
struct kinfo_proc *
kvm_getprocs(kd, op, arg, cnt)
kvm_t *kd;
int op, arg;
int *cnt;
{
int mib[4], size, st, nprocs;
if (kd->procbase != 0) {
free((void *)kd->procbase);
/*
* Clear this pointer in case this call fails. Otherwise,
* kvm_close() will free it again.
*/
kd->procbase = 0;
}
if (ISALIVE(kd)) {
size = 0;
mib[0] = CTL_KERN;
mib[1] = KERN_PROC;
mib[2] = op;
mib[3] = arg;
st = sysctl(mib, op == KERN_PROC_ALL ? 3 : 4, NULL, &size, NULL, 0);
if (st == -1) {
_kvm_syserr(kd, kd->program, "kvm_getprocs");
return (0);
}
kd->procbase = (struct kinfo_proc *)_kvm_malloc(kd, size);
if (kd->procbase == 0)
return (0);
st = sysctl(mib, op == KERN_PROC_ALL ? 3 : 4, kd->procbase, &size, NULL, 0);
if (st == -1) {
_kvm_syserr(kd, kd->program, "kvm_getprocs");
return (0);
}
if (size % sizeof(struct kinfo_proc) != 0) {
_kvm_err(kd, kd->program,
"proc size mismatch (%d total, %d chunks)",
size, sizeof(struct kinfo_proc));
return (0);
}
nprocs = size / sizeof(struct kinfo_proc);
} else {
struct nlist nl[4], *p;
nl[0].n_name = "_nprocs";
nl[1].n_name = "_allproc";
nl[2].n_name = "_zombproc";
nl[3].n_name = 0;
if (kvm_nlist(kd, nl) != 0) {
for (p = nl; p->n_type != 0; ++p)
;
_kvm_err(kd, kd->program,
"%s: no such symbol", p->n_name);
return (0);
}
if (KREAD(kd, nl[0].n_value, &nprocs)) {
_kvm_err(kd, kd->program, "can't read nprocs");
return (0);
}
size = nprocs * sizeof(struct kinfo_proc);
kd->procbase = (struct kinfo_proc *)_kvm_malloc(kd, size);
if (kd->procbase == 0)
return (0);
nprocs = kvm_deadprocs(kd, op, arg, nl[1].n_value,
nl[2].n_value, nprocs);
#ifdef notdef
size = nprocs * sizeof(struct kinfo_proc);
(void)realloc(kd->procbase, size);
#endif
}
*cnt = nprocs;
return (kd->procbase);
}
void
_kvm_freeprocs(kd)
kvm_t *kd;
{
if (kd->procbase) {
free(kd->procbase);
kd->procbase = 0;
}
}
void *
_kvm_realloc(kd, p, n)
kvm_t *kd;
void *p;
size_t n;
{
void *np = (void *)realloc(p, n);
if (np == 0)
_kvm_err(kd, kd->program, "out of memory");
return (np);
}
#ifndef MAX
#define MAX(a, b) ((a) > (b) ? (a) : (b))
#endif
/*
* Read in an argument vector from the user address space of process p.
* addr if the user-space base address of narg null-terminated contiguous
* strings. This is used to read in both the command arguments and
* environment strings. Read at most maxcnt characters of strings.
*/
static char **
kvm_argv(kd, p, addr, narg, maxcnt)
kvm_t *kd;
const struct proc *p;
register u_long addr;
register int narg;
register int maxcnt;
{
register char *np, *cp, *ep, *ap;
register u_long oaddr = -1;
register int len, cc;
register char **argv;
/*
* Check that there aren't an unreasonable number of agruments,
* and that the address is in user space.
*/
if (narg > 512 || addr < VM_MIN_ADDRESS || addr >= VM_MAXUSER_ADDRESS)
return (0);
/*
* kd->argv : work space for fetching the strings from the target
* process's space, and is converted for returning to caller
*/
if (kd->argv == 0) {
/*
* Try to avoid reallocs.
*/
kd->argc = MAX(narg + 1, 32);
kd->argv = (char **)_kvm_malloc(kd, kd->argc *
sizeof(*kd->argv));
if (kd->argv == 0)
return (0);
} else if (narg + 1 > kd->argc) {
kd->argc = MAX(2 * kd->argc, narg + 1);
kd->argv = (char **)_kvm_realloc(kd, kd->argv, kd->argc *
sizeof(*kd->argv));
if (kd->argv == 0)
return (0);
}
/*
* kd->argspc : returned to user, this is where the kd->argv
* arrays are left pointing to the collected strings.
*/
if (kd->argspc == 0) {
kd->argspc = (char *)_kvm_malloc(kd, PAGE_SIZE);
if (kd->argspc == 0)
return (0);
kd->arglen = PAGE_SIZE;
}
/*
* kd->argbuf : used to pull in pages from the target process.
* the strings are copied out of here.
*/
if (kd->argbuf == 0) {
kd->argbuf = (char *)_kvm_malloc(kd, PAGE_SIZE);
if (kd->argbuf == 0)
return (0);
}
/* Pull in the target process'es argv vector */
cc = sizeof(char *) * narg;
if (kvm_uread(kd, p, addr, (char *)kd->argv, cc) != cc)
return (0);
/*
* ap : saved start address of string we're working on in kd->argspc
* np : pointer to next place to write in kd->argspc
* len: length of data in kd->argspc
* argv: pointer to the argv vector that we are hunting around the
* target process space for, and converting to addresses in
* our address space (kd->argspc).
*/
ap = np = kd->argspc;
argv = kd->argv;
len = 0;
/*
* Loop over pages, filling in the argument vector.
* Note that the argv strings could be pointing *anywhere* in
* the user address space and are no longer contiguous.
* Note that *argv is modified when we are going to fetch a string
* that crosses a page boundary. We copy the next part of the string
* into to "np" and eventually convert the pointer.
*/
while (argv < kd->argv + narg && *argv != 0) {
/* get the address that the current argv string is on */
addr = (u_long)*argv & ~(PAGE_SIZE - 1);
/* is it the same page as the last one? */
if (addr != oaddr) {
if (kvm_uread(kd, p, addr, kd->argbuf, PAGE_SIZE) !=
PAGE_SIZE)
return (0);
oaddr = addr;
}
/* offset within the page... kd->argbuf */
addr = (u_long)*argv & (PAGE_SIZE - 1);
/* cp = start of string, cc = count of chars in this chunk */
cp = kd->argbuf + addr;
cc = PAGE_SIZE - addr;
/* dont get more than asked for by user process */
if (maxcnt > 0 && cc > maxcnt - len)
cc = maxcnt - len;
/* pointer to end of string if we found it in this page */
ep = memchr(cp, '\0', cc);
if (ep != 0)
cc = ep - cp + 1;
/*
* at this point, cc is the count of the chars that we are
* going to retrieve this time. we may or may not have found
* the end of it. (ep points to the null if the end is known)
*/
/* will we exceed the malloc/realloced buffer? */
if (len + cc > kd->arglen) {
register int off;
register char **pp;
register char *op = kd->argspc;
kd->arglen *= 2;
kd->argspc = (char *)_kvm_realloc(kd, kd->argspc,
kd->arglen);
if (kd->argspc == 0)
return (0);
/*
* Adjust argv pointers in case realloc moved
* the string space.
*/
off = kd->argspc - op;
for (pp = kd->argv; pp < argv; pp++)
*pp += off;
ap += off;
np += off;
}
/* np = where to put the next part of the string in kd->argspc*/
/* np is kinda redundant.. could use "kd->argspc + len" */
memcpy(np, cp, cc);
np += cc; /* inc counters */
len += cc;
/*
* if end of string found, set the *argv pointer to the
* saved beginning of string, and advance. argv points to
* somewhere in kd->argv.. This is initially relative
* to the target process, but when we close it off, we set
* it to point in our address space.
*/
if (ep != 0) {
*argv++ = ap;
ap = np;
} else {
/* update the address relative to the target process */
*argv += cc;
}
if (maxcnt > 0 && len >= maxcnt) {
/*
* We're stopping prematurely. Terminate the
* current string.
*/
if (ep == 0) {
*np = '\0';
*argv++ = ap;
}
break;
}
}
/* Make sure argv is terminated. */
*argv = 0;
return (kd->argv);
}
static void
ps_str_a(p, addr, n)
struct ps_strings *p;
u_long *addr;
int *n;
{
*addr = (u_long)p->ps_argvstr;
*n = p->ps_nargvstr;
}
static void
ps_str_e(p, addr, n)
struct ps_strings *p;
u_long *addr;
int *n;
{
*addr = (u_long)p->ps_envstr;
*n = p->ps_nenvstr;
}
/*
* Determine if the proc indicated by p is still active.
* This test is not 100% foolproof in theory, but chances of
* being wrong are very low.
*/
static int
proc_verify(kd, kernp, p)
kvm_t *kd;
u_long kernp;
const struct proc *p;
{
struct proc kernproc;
/*
* Just read in the whole proc. It's not that big relative
* to the cost of the read system call.
*/
if (kvm_read(kd, kernp, (char *)&kernproc, sizeof(kernproc)) !=
sizeof(kernproc))
return (0);
return (p->p_pid == kernproc.p_pid &&
(kernproc.p_stat != SZOMB || p->p_stat == SZOMB));
}
static char **
kvm_doargv(kd, kp, nchr, info)
kvm_t *kd;
const struct kinfo_proc *kp;
int nchr;
void (*info)(struct ps_strings *, u_long *, int *);
{
register const struct proc *p = &kp->kp_proc;
register char **ap;
u_long addr;
int cnt;
struct ps_strings arginfo, *ps_strings;
int mib[2];
size_t len;
ps_strings = NULL;
mib[0] = CTL_KERN;
mib[1] = KERN_PS_STRINGS;
len = sizeof(ps_strings);
if (sysctl(mib, 2, &ps_strings, &len, NULL, 0) < 0 ||
ps_strings == NULL)
ps_strings = PS_STRINGS;
/*
* Pointers are stored at the top of the user stack.
*/
if (p->p_stat == SZOMB ||
kvm_uread(kd, p, ps_strings, (char *)&arginfo,
sizeof(arginfo)) != sizeof(arginfo))
return (0);
(*info)(&arginfo, &addr, &cnt);
if (cnt == 0)
return (0);
ap = kvm_argv(kd, p, addr, cnt, nchr);
/*
* For live kernels, make sure this process didn't go away.
*/
if (ap != 0 && ISALIVE(kd) &&
!proc_verify(kd, (u_long)kp->kp_eproc.e_paddr, p))
ap = 0;
return (ap);
}
/*
* Get the command args. This code is now machine independent.
*/
char **
kvm_getargv(kd, kp, nchr)
kvm_t *kd;
const struct kinfo_proc *kp;
int nchr;
{
return (kvm_doargv(kd, kp, nchr, ps_str_a));
}
char **
kvm_getenvv(kd, kp, nchr)
kvm_t *kd;
const struct kinfo_proc *kp;
int nchr;
{
return (kvm_doargv(kd, kp, nchr, ps_str_e));
}
/*
* Read from user space. The user context is given by p.
*/
ssize_t
kvm_uread(kd, p, uva, buf, len)
kvm_t *kd;
register const struct proc *p;
register u_long uva;
register char *buf;
register size_t len;
{
register char *cp;
char procfile[MAXPATHLEN];
ssize_t amount;
int fd;
if (!ISALIVE(kd)) {
_kvm_err(kd, kd->program, "cannot read user space from dead kernel");
return(0);
}
cp = buf;
sprintf(procfile, "/proc/%d/mem", p->p_pid);
fd = open(procfile, O_RDONLY, 0);
if (fd < 0) {
_kvm_err(kd, kd->program, "cannot open %s", procfile);
close(fd);
return (0);
}
while (len > 0) {
if (lseek(fd, (off_t)uva, 0) == -1 && errno != 0) {
_kvm_err(kd, kd->program, "invalid address (%x) in %s", uva, procfile);
break;
}
amount = read(fd, cp, len);
if (amount < 0) {
_kvm_err(kd, kd->program, "error reading %s", procfile);
break;
}
cp += amount;
uva += amount;
len -= amount;
}
close(fd);
return (ssize_t)(cp - buf);
}