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freebsd-dev/lib/libkvm/kvm_proc.c
Ulrich Spörlein de788839e2 libkvm: fix process runtime calculation on crashdumps 
Fix a long standing bug, where the procs ticks where assumed to be in
us. Instead, read cpu_tick_frequency from the kernel and use the same
logic to convert runtime. This is still too optimistic in that it
assumes cpu_tick_frequency is available and fixed. Since this function
is only called on crashdumps, I think we can live with that. Testing has
shown the values to be correct for different kern.hz inside Virtualbox.

Bump WARNS. Alignment issues on some archs mean this is still at 3.

Reviewed by:	bde
2011-01-23 11:08:36 +00:00

1005 lines
26 KiB
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/*-
* 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.
* 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 0
#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)kvm_proc.c 8.3 (Berkeley) 9/23/93";
#endif /* LIBC_SCCS and not lint */
#endif
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
/*
* 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>
#define _WANT_UCRED /* make ucred.h give us 'struct ucred' */
#include <sys/ucred.h>
#include <sys/queue.h>
#include <sys/_lock.h>
#include <sys/_mutex.h>
#include <sys/_task.h>
#include <sys/cpuset.h>
#include <sys/user.h>
#include <sys/proc.h>
#define _WANT_PRISON /* make jail.h give us 'struct prison' */
#include <sys/jail.h>
#include <sys/exec.h>
#include <sys/stat.h>
#include <sys/sysent.h>
#include <sys/ioctl.h>
#include <sys/tty.h>
#include <sys/file.h>
#include <sys/conf.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 <sys/sysctl.h>
#include <limits.h>
#include <memory.h>
#include <paths.h>
#include "kvm_private.h"
#define KREAD(kd, addr, obj) \
(kvm_read(kd, addr, (char *)(obj), sizeof(*obj)) != sizeof(*obj))
static int ticks;
static int hz;
static uint64_t cpu_tick_frequency;
/*
* From sys/kern/kern_tc.c. Depends on cpu_tick_frequency, which is
* read/initialized before this function is ever called.
*/
static uint64_t
cputick2usec(uint64_t tick)
{
if (cpu_tick_frequency == 0)
return (0);
if (tick > 18446744073709551) /* floor(2^64 / 1000) */
return (tick / (cpu_tick_frequency / 1000000));
else if (tick > 18446744073709) /* floor(2^64 / 1000000) */
return ((tick * 1000) / (cpu_tick_frequency / 1000));
else
return ((tick * 1000000) / cpu_tick_frequency);
}
/*
* Read proc's from memory file into buffer bp, which has space to hold
* at most maxcnt procs.
*/
static int
kvm_proclist(kvm_t *kd, int what, int arg, struct proc *p,
struct kinfo_proc *bp, int maxcnt)
{
int cnt = 0;
struct kinfo_proc kinfo_proc, *kp;
struct pgrp pgrp;
struct session sess;
struct cdev t_cdev;
struct tty tty;
struct vmspace vmspace;
struct sigacts sigacts;
#if 0
struct pstats pstats;
#endif
struct ucred ucred;
struct prison pr;
struct thread mtd;
struct proc proc;
struct proc pproc;
struct sysentvec sysent;
char svname[KI_EMULNAMELEN];
kp = &kinfo_proc;
kp->ki_structsize = sizeof(kinfo_proc);
/*
* Loop on the processes. this is completely broken because we need to be
* able to loop on the threads and merge the ones that are the same process some how.
*/
for (; cnt < maxcnt && p != NULL; p = LIST_NEXT(&proc, p_list)) {
memset(kp, 0, sizeof *kp);
if (KREAD(kd, (u_long)p, &proc)) {
_kvm_err(kd, kd->program, "can't read proc at %p", p);
return (-1);
}
if (proc.p_state != PRS_ZOMBIE) {
if (KREAD(kd, (u_long)TAILQ_FIRST(&proc.p_threads),
&mtd)) {
_kvm_err(kd, kd->program,
"can't read thread at %p",
TAILQ_FIRST(&proc.p_threads));
return (-1);
}
}
if (KREAD(kd, (u_long)proc.p_ucred, &ucred) == 0) {
kp->ki_ruid = ucred.cr_ruid;
kp->ki_svuid = ucred.cr_svuid;
kp->ki_rgid = ucred.cr_rgid;
kp->ki_svgid = ucred.cr_svgid;
kp->ki_cr_flags = ucred.cr_flags;
if (ucred.cr_ngroups > KI_NGROUPS) {
kp->ki_ngroups = KI_NGROUPS;
kp->ki_cr_flags |= KI_CRF_GRP_OVERFLOW;
} else
kp->ki_ngroups = ucred.cr_ngroups;
kvm_read(kd, (u_long)ucred.cr_groups, kp->ki_groups,
kp->ki_ngroups * sizeof(gid_t));
kp->ki_uid = ucred.cr_uid;
if (ucred.cr_prison != NULL) {
if (KREAD(kd, (u_long)ucred.cr_prison, &pr)) {
_kvm_err(kd, kd->program,
"can't read prison at %p",
ucred.cr_prison);
return (-1);
}
kp->ki_jid = pr.pr_id;
}
}
switch(what & ~KERN_PROC_INC_THREAD) {
case KERN_PROC_GID:
if (kp->ki_groups[0] != (gid_t)arg)
continue;
break;
case KERN_PROC_PID:
if (proc.p_pid != (pid_t)arg)
continue;
break;
case KERN_PROC_RGID:
if (kp->ki_rgid != (gid_t)arg)
continue;
break;
case KERN_PROC_UID:
if (kp->ki_uid != (uid_t)arg)
continue;
break;
case KERN_PROC_RUID:
if (kp->ki_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 kinfo_proc
*/
kp->ki_paddr = p;
kp->ki_addr = 0; /* XXX uarea */
/* kp->ki_kstack = proc.p_thread.td_kstack; XXXKSE */
kp->ki_args = proc.p_args;
kp->ki_tracep = proc.p_tracevp;
kp->ki_textvp = proc.p_textvp;
kp->ki_fd = proc.p_fd;
kp->ki_vmspace = proc.p_vmspace;
if (proc.p_sigacts != NULL) {
if (KREAD(kd, (u_long)proc.p_sigacts, &sigacts)) {
_kvm_err(kd, kd->program,
"can't read sigacts at %p", proc.p_sigacts);
return (-1);
}
kp->ki_sigignore = sigacts.ps_sigignore;
kp->ki_sigcatch = sigacts.ps_sigcatch;
}
#if 0
if ((proc.p_flag & P_INMEM) && proc.p_stats != NULL) {
if (KREAD(kd, (u_long)proc.p_stats, &pstats)) {
_kvm_err(kd, kd->program,
"can't read stats at %x", proc.p_stats);
return (-1);
}
kp->ki_start = pstats.p_start;
/*
* XXX: The times here are probably zero and need
* to be calculated from the raw data in p_rux and
* p_crux.
*/
kp->ki_rusage = pstats.p_ru;
kp->ki_childstime = pstats.p_cru.ru_stime;
kp->ki_childutime = pstats.p_cru.ru_utime;
/* Some callers want child-times in a single value */
timeradd(&kp->ki_childstime, &kp->ki_childutime,
&kp->ki_childtime);
}
#endif
if (proc.p_oppid)
kp->ki_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 %p", proc.p_pptr);
return (-1);
}
kp->ki_ppid = pproc.p_pid;
} else
kp->ki_ppid = 0;
if (proc.p_pgrp == NULL)
goto nopgrp;
if (KREAD(kd, (u_long)proc.p_pgrp, &pgrp)) {
_kvm_err(kd, kd->program, "can't read pgrp at %p",
proc.p_pgrp);
return (-1);
}
kp->ki_pgid = pgrp.pg_id;
kp->ki_jobc = pgrp.pg_jobc;
if (KREAD(kd, (u_long)pgrp.pg_session, &sess)) {
_kvm_err(kd, kd->program, "can't read session at %p",
pgrp.pg_session);
return (-1);
}
kp->ki_sid = sess.s_sid;
(void)memcpy(kp->ki_login, sess.s_login,
sizeof(kp->ki_login));
kp->ki_kiflag = sess.s_ttyvp ? KI_CTTY : 0;
if (sess.s_leader == p)
kp->ki_kiflag |= KI_SLEADER;
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 %p", sess.s_ttyp);
return (-1);
}
if (tty.t_dev != NULL) {
if (KREAD(kd, (u_long)tty.t_dev, &t_cdev)) {
_kvm_err(kd, kd->program,
"can't read cdev at %p",
tty.t_dev);
return (-1);
}
#if 0
kp->ki_tdev = t_cdev.si_udev;
#else
kp->ki_tdev = NODEV;
#endif
}
if (tty.t_pgrp != NULL) {
if (KREAD(kd, (u_long)tty.t_pgrp, &pgrp)) {
_kvm_err(kd, kd->program,
"can't read tpgrp at %p",
tty.t_pgrp);
return (-1);
}
kp->ki_tpgid = pgrp.pg_id;
} else
kp->ki_tpgid = -1;
if (tty.t_session != NULL) {
if (KREAD(kd, (u_long)tty.t_session, &sess)) {
_kvm_err(kd, kd->program,
"can't read session at %p",
tty.t_session);
return (-1);
}
kp->ki_tsid = sess.s_sid;
}
} else {
nopgrp:
kp->ki_tdev = NODEV;
}
if ((proc.p_state != PRS_ZOMBIE) && mtd.td_wmesg)
(void)kvm_read(kd, (u_long)mtd.td_wmesg,
kp->ki_wmesg, WMESGLEN);
(void)kvm_read(kd, (u_long)proc.p_vmspace,
(char *)&vmspace, sizeof(vmspace));
kp->ki_size = vmspace.vm_map.size;
/*
* Approximate the kernel's method of calculating
* this field.
*/
#define pmap_resident_count(pm) ((pm)->pm_stats.resident_count)
kp->ki_rssize = pmap_resident_count(&vmspace.vm_pmap);
kp->ki_swrss = vmspace.vm_swrss;
kp->ki_tsize = vmspace.vm_tsize;
kp->ki_dsize = vmspace.vm_dsize;
kp->ki_ssize = vmspace.vm_ssize;
switch (what & ~KERN_PROC_INC_THREAD) {
case KERN_PROC_PGRP:
if (kp->ki_pgid != (pid_t)arg)
continue;
break;
case KERN_PROC_SESSION:
if (kp->ki_sid != (pid_t)arg)
continue;
break;
case KERN_PROC_TTY:
if ((proc.p_flag & P_CONTROLT) == 0 ||
kp->ki_tdev != (dev_t)arg)
continue;
break;
}
if (proc.p_comm[0] != 0)
strlcpy(kp->ki_comm, proc.p_comm, MAXCOMLEN);
(void)kvm_read(kd, (u_long)proc.p_sysent, (char *)&sysent,
sizeof(sysent));
(void)kvm_read(kd, (u_long)sysent.sv_name, (char *)&svname,
sizeof(svname));
if (svname[0] != 0)
strlcpy(kp->ki_emul, svname, KI_EMULNAMELEN);
if ((proc.p_state != PRS_ZOMBIE) &&
(mtd.td_blocked != 0)) {
kp->ki_kiflag |= KI_LOCKBLOCK;
if (mtd.td_lockname)
(void)kvm_read(kd,
(u_long)mtd.td_lockname,
kp->ki_lockname, LOCKNAMELEN);
kp->ki_lockname[LOCKNAMELEN] = 0;
}
kp->ki_runtime = cputick2usec(proc.p_rux.rux_runtime);
kp->ki_pid = proc.p_pid;
kp->ki_siglist = proc.p_siglist;
SIGSETOR(kp->ki_siglist, mtd.td_siglist);
kp->ki_sigmask = mtd.td_sigmask;
kp->ki_xstat = proc.p_xstat;
kp->ki_acflag = proc.p_acflag;
kp->ki_lock = proc.p_lock;
if (proc.p_state != PRS_ZOMBIE) {
kp->ki_swtime = (ticks - proc.p_swtick) / hz;
kp->ki_flag = proc.p_flag;
kp->ki_sflag = 0;
kp->ki_nice = proc.p_nice;
kp->ki_traceflag = proc.p_traceflag;
if (proc.p_state == PRS_NORMAL) {
if (TD_ON_RUNQ(&mtd) ||
TD_CAN_RUN(&mtd) ||
TD_IS_RUNNING(&mtd)) {
kp->ki_stat = SRUN;
} else if (mtd.td_state ==
TDS_INHIBITED) {
if (P_SHOULDSTOP(&proc)) {
kp->ki_stat = SSTOP;
} else if (
TD_IS_SLEEPING(&mtd)) {
kp->ki_stat = SSLEEP;
} else if (TD_ON_LOCK(&mtd)) {
kp->ki_stat = SLOCK;
} else {
kp->ki_stat = SWAIT;
}
}
} else {
kp->ki_stat = SIDL;
}
/* Stuff from the thread */
kp->ki_pri.pri_level = mtd.td_priority;
kp->ki_pri.pri_native = mtd.td_base_pri;
kp->ki_lastcpu = mtd.td_lastcpu;
kp->ki_wchan = mtd.td_wchan;
if (mtd.td_name[0] != 0)
strlcpy(kp->ki_ocomm, mtd.td_name, MAXCOMLEN);
kp->ki_oncpu = mtd.td_oncpu;
if (mtd.td_name[0] != '\0')
strlcpy(kp->ki_ocomm, mtd.td_name, sizeof(kp->ki_ocomm));
kp->ki_pctcpu = 0;
kp->ki_rqindex = 0;
} else {
kp->ki_stat = SZOMB;
}
bcopy(&kinfo_proc, bp, sizeof(kinfo_proc));
++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(kvm_t *kd, int what, int arg, u_long a_allproc,
u_long a_zombproc, int maxcnt)
{
struct kinfo_proc *bp = kd->procbase;
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(kvm_t *kd, int op, int arg, int *cnt)
{
int mib[4], st, nprocs;
size_t size;
int temp_op;
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;
temp_op = op & ~KERN_PROC_INC_THREAD;
st = sysctl(mib,
temp_op == KERN_PROC_ALL || temp_op == KERN_PROC_PROC ?
3 : 4, NULL, &size, NULL, 0);
if (st == -1) {
_kvm_syserr(kd, kd->program, "kvm_getprocs");
return (0);
}
/*
* We can't continue with a size of 0 because we pass
* it to realloc() (via _kvm_realloc()), and passing 0
* to realloc() results in undefined behavior.
*/
if (size == 0) {
/*
* XXX: We should probably return an invalid,
* but non-NULL, pointer here so any client
* program trying to dereference it will
* crash. However, _kvm_freeprocs() calls
* free() on kd->procbase if it isn't NULL,
* and free()'ing a junk pointer isn't good.
* Then again, _kvm_freeprocs() isn't used
* anywhere . . .
*/
kd->procbase = _kvm_malloc(kd, 1);
goto liveout;
}
do {
size += size / 10;
kd->procbase = (struct kinfo_proc *)
_kvm_realloc(kd, kd->procbase, size);
if (kd->procbase == 0)
return (0);
st = sysctl(mib, temp_op == KERN_PROC_ALL ||
temp_op == KERN_PROC_PROC ? 3 : 4,
kd->procbase, &size, NULL, 0);
} while (st == -1 && errno == ENOMEM);
if (st == -1) {
_kvm_syserr(kd, kd->program, "kvm_getprocs");
return (0);
}
/*
* We have to check the size again because sysctl()
* may "round up" oldlenp if oldp is NULL; hence it
* might've told us that there was data to get when
* there really isn't any.
*/
if (size > 0 &&
kd->procbase->ki_structsize != sizeof(struct kinfo_proc)) {
_kvm_err(kd, kd->program,
"kinfo_proc size mismatch (expected %zu, got %d)",
sizeof(struct kinfo_proc),
kd->procbase->ki_structsize);
return (0);
}
liveout:
nprocs = size == 0 ? 0 : size / kd->procbase->ki_structsize;
} else {
struct nlist nl[7], *p;
nl[0].n_name = "_nprocs";
nl[1].n_name = "_allproc";
nl[2].n_name = "_zombproc";
nl[3].n_name = "_ticks";
nl[4].n_name = "_hz";
nl[5].n_name = "_cpu_tick_frequency";
nl[6].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);
}
if (KREAD(kd, nl[3].n_value, &ticks)) {
_kvm_err(kd, kd->program, "can't read ticks");
return (0);
}
if (KREAD(kd, nl[4].n_value, &hz)) {
_kvm_err(kd, kd->program, "can't read hz");
return (0);
}
if (KREAD(kd, nl[5].n_value, &cpu_tick_frequency)) {
_kvm_err(kd, kd->program,
"can't read cpu_tick_frequency");
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(kvm_t *kd)
{
if (kd->procbase) {
free(kd->procbase);
kd->procbase = 0;
}
}
void *
_kvm_realloc(kvm_t *kd, void *p, size_t n)
{
void *np = (void *)realloc(p, n);
if (np == 0) {
free(p);
_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 kp.
* 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(kvm_t *kd, const struct kinfo_proc *kp, u_long addr, int narg,
int maxcnt)
{
char *np, *cp, *ep, *ap;
u_long oaddr = -1;
int len, cc;
char **argv;
/*
* Check that there aren't an unreasonable number of arguments,
* and that the address is in user space. Special test for
* VM_MIN_ADDRESS as it evaluates to zero, but is not a simple zero
* constant for some archs. We cannot use the pre-processor here and
* for some archs the compiler would trigger a signedness warning.
*/
if (narg > 512 || addr + 1 < VM_MIN_ADDRESS + 1 || 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, kp, 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, kp, 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) {
int off;
char **pp;
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(struct ps_strings *p, u_long *addr, int *n)
{
*addr = (u_long)p->ps_argvstr;
*n = p->ps_nargvstr;
}
static void
ps_str_e (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(const struct kinfo_proc *curkp)
{
struct kinfo_proc newkp;
int mib[4];
size_t len;
mib[0] = CTL_KERN;
mib[1] = KERN_PROC;
mib[2] = KERN_PROC_PID;
mib[3] = curkp->ki_pid;
len = sizeof(newkp);
if (sysctl(mib, 4, &newkp, &len, NULL, 0) == -1)
return (0);
return (curkp->ki_pid == newkp.ki_pid &&
(newkp.ki_stat != SZOMB || curkp->ki_stat == SZOMB));
}
static char **
kvm_doargv(kvm_t *kd, const struct kinfo_proc *kp, int nchr,
void (*info)(struct ps_strings *, u_long *, int *))
{
char **ap;
u_long addr;
int cnt;
static struct ps_strings arginfo;
static u_long ps_strings;
size_t len;
if (ps_strings == 0) {
len = sizeof(ps_strings);
if (sysctlbyname("kern.ps_strings", &ps_strings, &len, NULL,
0) == -1)
ps_strings = PS_STRINGS;
}
/*
* Pointers are stored at the top of the user stack.
*/
if (kp->ki_stat == SZOMB ||
kvm_uread(kd, kp, ps_strings, (char *)&arginfo,
sizeof(arginfo)) != sizeof(arginfo))
return (0);
(*info)(&arginfo, &addr, &cnt);
if (cnt == 0)
return (0);
ap = kvm_argv(kd, kp, addr, cnt, nchr);
/*
* For live kernels, make sure this process didn't go away.
*/
if (ap != 0 && ISALIVE(kd) && !proc_verify(kp))
ap = 0;
return (ap);
}
/*
* Get the command args. This code is now machine independent.
*/
char **
kvm_getargv(kvm_t *kd, const struct kinfo_proc *kp, int nchr)
{
int oid[4];
int i;
size_t bufsz;
static unsigned long buflen;
static char *buf, *p;
static char **bufp;
static int argc;
if (!ISALIVE(kd)) {
_kvm_err(kd, kd->program,
"cannot read user space from dead kernel");
return (0);
}
if (!buflen) {
bufsz = sizeof(buflen);
i = sysctlbyname("kern.ps_arg_cache_limit",
&buflen, &bufsz, NULL, 0);
if (i == -1) {
buflen = 0;
} else {
buf = malloc(buflen);
if (buf == NULL)
buflen = 0;
argc = 32;
bufp = malloc(sizeof(char *) * argc);
}
}
if (buf != NULL) {
oid[0] = CTL_KERN;
oid[1] = KERN_PROC;
oid[2] = KERN_PROC_ARGS;
oid[3] = kp->ki_pid;
bufsz = buflen;
i = sysctl(oid, 4, buf, &bufsz, 0, 0);
if (i == 0 && bufsz > 0) {
i = 0;
p = buf;
do {
bufp[i++] = p;
p += strlen(p) + 1;
if (i >= argc) {
argc += argc;
bufp = realloc(bufp,
sizeof(char *) * argc);
}
} while (p < buf + bufsz);
bufp[i++] = 0;
return (bufp);
}
}
if (kp->ki_flag & P_SYSTEM)
return (NULL);
return (kvm_doargv(kd, kp, nchr, ps_str_a));
}
char **
kvm_getenvv(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(kvm_t *kd, const struct kinfo_proc *kp, u_long uva, char *buf,
size_t len)
{
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);
}
sprintf(procfile, "/proc/%d/mem", kp->ki_pid);
fd = open(procfile, O_RDONLY, 0);
if (fd < 0) {
_kvm_err(kd, kd->program, "cannot open %s", procfile);
return (0);
}
cp = buf;
while (len > 0) {
errno = 0;
if (lseek(fd, (off_t)uva, 0) == -1 && errno != 0) {
_kvm_err(kd, kd->program, "invalid address (%lx) in %s",
uva, procfile);
break;
}
amount = read(fd, cp, len);
if (amount < 0) {
_kvm_syserr(kd, kd->program, "error reading %s",
procfile);
break;
}
if (amount == 0) {
_kvm_err(kd, kd->program, "EOF reading %s", procfile);
break;
}
cp += amount;
uva += amount;
len -= amount;
}
close(fd);
return ((ssize_t)(cp - buf));
}
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