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c281fdb153
freebsd/lib/libkvm/kvm_proc.c
John Baldwin 7f911abe54 Add support to libkvm for reading vmcores from other architectures. 
- Add a kvaddr_type to represent kernel virtual addresses instead of
  unsigned long.
- Add a struct kvm_nlist which is a stripped down version of struct nlist
  that uses kvaddr_t for n_value.
- Add a kvm_native() routine that returns true if an open kvm descriptor
  is for a native kernel and memory image.
- Add a kvm_open2() function similar to kvm_openfiles().  It drops the
  unused 'swapfile' argument and adds a new function pointer argument for
  a symbol resolving function.  Native kernels still use _fdnlist() from
  libc to resolve symbols if a resolver function is not supplied, but cross
  kernels require a resolver.
- Add a kvm_nlist2() function similar to kvm_nlist() except that it uses
  struct kvm_nlist instead of struct nlist.
- Add a kvm_read2() function similar to kvm_read() except that it uses
  kvaddr_t instead of unsigned long for the kernel virtual address.
- Add a new kvm_arch switch of routines needed by a vmcore backend.
  Each backend is responsible for implementing kvm_read2() for a given
  vmcore format.
- Use libelf to read headers from ELF kernels and cores (except for
  powerpc cores).
- Add internal helper routines for the common page offset hash table used
  by the minidump backends.
- Port all of the existing kvm backends to implement a kvm_arch switch and
  to be cross-friendly by using private constants instead of ones that
  vary by platform (e.g. PAGE_SIZE).  Static assertions are present when
  a given backend is compiled natively to ensure the private constants
  match the real ones.
- Enable all of the existing vmcore backends on all platforms.  This means
  that libkvm on any platform should be able to perform KVA translation
  and read data from a vmcore of any platform.

Tested on:	amd64, i386, sparc64 (marius)
Differential Revision:	https://reviews.freebsd.org/D3341
2015-11-27 18:58:26 +00:00

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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>
#define _WANT_KW_EXITCODE
#include <sys/wait.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <nlist.h>
#include <kvm.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_NEW)
continue;
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 = KW_EXITCODE(proc.p_xexit, proc.p_xsig);
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_tdname, mtd.td_name, MAXCOMLEN);
kp->ki_oncpu = mtd.td_oncpu;
if (mtd.td_name[0] != '\0')
strlcpy(kp->ki_tdname, mtd.td_name, sizeof(kp->ki_tdname));
kp->ki_pctcpu = 0;
kp->ki_rqindex = 0;
/*
* Note: legacy fields; wraps at NO_CPU_OLD or the
* old max CPU value as appropriate
*/
if (mtd.td_lastcpu == NOCPU)
kp->ki_lastcpu_old = NOCPU_OLD;
else if (mtd.td_lastcpu > MAXCPU_OLD)
kp->ki_lastcpu_old = MAXCPU_OLD;
else
kp->ki_lastcpu_old = mtd.td_lastcpu;
if (mtd.td_oncpu == NOCPU)
kp->ki_oncpu_old = NOCPU_OLD;
else if (mtd.td_oncpu > MAXCPU_OLD)
kp->ki_oncpu_old = MAXCPU_OLD;
else
kp->ki_oncpu_old = mtd.td_oncpu;
} 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, osize;
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);
osize = size;
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 && size == osize);
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 (!kd->arch->ka_native(kd)) {
_kvm_err(kd, kd->program,
"cannot read procs from non-native core");
return (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);
if (nprocs <= 0) {
_kvm_freeprocs(kd);
nprocs = 0;
}
#ifdef notdef
else {
size = nprocs * sizeof(struct kinfo_proc);
kd->procbase = 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);
}
/*
* Get the command args or environment.
*/
static char **
kvm_argv(kvm_t *kd, const struct kinfo_proc *kp, int env, int nchr)
{
int oid[4];
int i;
size_t bufsz;
static int 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 (nchr == 0 || nchr > ARG_MAX)
nchr = ARG_MAX;
if (buflen == 0) {
buf = malloc(nchr);
if (buf == NULL) {
_kvm_err(kd, kd->program, "cannot allocate memory");
return (0);
}
buflen = nchr;
argc = 32;
bufp = malloc(sizeof(char *) * argc);
} else if (nchr > buflen) {
p = realloc(buf, nchr);
if (p != NULL) {
buf = p;
buflen = nchr;
}
}
oid[0] = CTL_KERN;
oid[1] = KERN_PROC;
oid[2] = env ? KERN_PROC_ENV : KERN_PROC_ARGS;
oid[3] = kp->ki_pid;
bufsz = buflen;
if (sysctl(oid, 4, buf, &bufsz, 0, 0) == -1) {
/*
* If the supplied buf is too short to hold the requested
* value the sysctl returns with ENOMEM. The buf is filled
* with the truncated value and the returned bufsz is equal
* to the requested len.
*/
if (errno != ENOMEM || bufsz != (size_t)buflen)
return (0);
buf[bufsz - 1] = '\0';
errno = 0;
} else if (bufsz == 0) {
return (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);
}
char **
kvm_getargv(kvm_t *kd, const struct kinfo_proc *kp, int nchr)
{
return (kvm_argv(kd, kp, 0, nchr));
}
char **
kvm_getenvv(kvm_t *kd, const struct kinfo_proc *kp, int nchr)
{
return (kvm_argv(kd, kp, 1, nchr));
}
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