freebsd-dev/lib/libproc/proc_util.c
Mark Johnston b043b5dc6b libproc: Add support for some proc_attach() flags.
This change adds some handling for the equivalent of Solaris' PGRAB_*
flags. In particular, support for PGRAB_RDONLY is needed to avoid a
nasty deadlock: dtrace(1) may otherwise stop the master process for its
pseudo-terminal and end up blocking while writing to standard output.
2016-12-06 04:22:38 +00:00

243 lines
5.1 KiB
C

/*-
* Copyright (c) 2010 The FreeBSD Foundation
* Copyright (c) 2008 John Birrell (jb@freebsd.org)
* All rights reserved.
*
* Portions of this software were developed by Rui Paulo under sponsorship
* from the FreeBSD Foundation.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/types.h>
#include <sys/ptrace.h>
#include <sys/wait.h>
#include <err.h>
#include <errno.h>
#include <signal.h>
#include <string.h>
#include <unistd.h>
#include "_libproc.h"
int
proc_clearflags(struct proc_handle *phdl, int mask)
{
if (phdl == NULL)
return (EINVAL);
phdl->flags &= ~mask;
return (0);
}
/*
* NB: we return -1 as the Solaris libproc Psetrun() function.
*/
int
proc_continue(struct proc_handle *phdl)
{
int pending;
if (phdl == NULL)
return (-1);
if (phdl->status == PS_STOP && WSTOPSIG(phdl->wstat) != SIGTRAP)
pending = WSTOPSIG(phdl->wstat);
else
pending = 0;
if (ptrace(PT_CONTINUE, proc_getpid(phdl), (caddr_t)(uintptr_t)1,
pending) != 0)
return (-1);
phdl->status = PS_RUN;
return (0);
}
int
proc_detach(struct proc_handle *phdl, int reason)
{
int status;
pid_t pid;
if (phdl == NULL)
return (EINVAL);
if (reason == PRELEASE_HANG)
return (EINVAL);
if (reason == PRELEASE_KILL) {
kill(proc_getpid(phdl), SIGKILL);
goto free;
}
if ((phdl->flags & PATTACH_RDONLY) != 0)
goto free;
pid = proc_getpid(phdl);
if (ptrace(PT_DETACH, pid, 0, 0) != 0 && errno == ESRCH)
goto free;
if (errno == EBUSY) {
kill(pid, SIGSTOP);
waitpid(pid, &status, WUNTRACED);
ptrace(PT_DETACH, pid, 0, 0);
kill(pid, SIGCONT);
}
free:
proc_free(phdl);
return (0);
}
int
proc_getflags(struct proc_handle *phdl)
{
if (phdl == NULL)
return (-1);
return (phdl->flags);
}
int
proc_setflags(struct proc_handle *phdl, int mask)
{
if (phdl == NULL)
return (EINVAL);
phdl->flags |= mask;
return (0);
}
int
proc_state(struct proc_handle *phdl)
{
if (phdl == NULL)
return (-1);
return (phdl->status);
}
int
proc_getmodel(struct proc_handle *phdl)
{
if (phdl == NULL)
return (-1);
return (phdl->model);
}
int
proc_wstatus(struct proc_handle *phdl)
{
int status;
if (phdl == NULL)
return (-1);
if (waitpid(proc_getpid(phdl), &status, WUNTRACED) < 0) {
if (errno != EINTR)
DPRINTF("waitpid");
return (-1);
}
if (WIFSTOPPED(status))
phdl->status = PS_STOP;
if (WIFEXITED(status) || WIFSIGNALED(status))
phdl->status = PS_UNDEAD;
phdl->wstat = status;
return (phdl->status);
}
int
proc_getwstat(struct proc_handle *phdl)
{
if (phdl == NULL)
return (-1);
return (phdl->wstat);
}
char *
proc_signame(int sig, char *name, size_t namesz)
{
strlcpy(name, strsignal(sig), namesz);
return (name);
}
int
proc_read(struct proc_handle *phdl, void *buf, size_t size, size_t addr)
{
struct ptrace_io_desc piod;
if (phdl == NULL)
return (-1);
piod.piod_op = PIOD_READ_D;
piod.piod_len = size;
piod.piod_addr = (void *)buf;
piod.piod_offs = (void *)addr;
if (ptrace(PT_IO, proc_getpid(phdl), (caddr_t)&piod, 0) < 0)
return (-1);
return (piod.piod_len);
}
const lwpstatus_t *
proc_getlwpstatus(struct proc_handle *phdl)
{
struct ptrace_lwpinfo lwpinfo;
lwpstatus_t *psp = &phdl->lwps;
siginfo_t *siginfo;
if (phdl == NULL)
return (NULL);
if (ptrace(PT_LWPINFO, proc_getpid(phdl), (caddr_t)&lwpinfo,
sizeof(lwpinfo)) < 0)
return (NULL);
siginfo = &lwpinfo.pl_siginfo;
if (lwpinfo.pl_event == PL_EVENT_SIGNAL &&
(lwpinfo.pl_flags & PL_FLAG_SI) != 0) {
if (siginfo->si_signo == SIGTRAP &&
(siginfo->si_code == TRAP_BRKPT ||
siginfo->si_code == TRAP_TRACE)) {
psp->pr_why = PR_FAULTED;
psp->pr_what = FLTBPT;
} else {
psp->pr_why = PR_SIGNALLED;
psp->pr_what = siginfo->si_signo;
}
} else if (lwpinfo.pl_flags & PL_FLAG_SCE) {
psp->pr_why = PR_SYSENTRY;
} else if (lwpinfo.pl_flags & PL_FLAG_SCX) {
psp->pr_why = PR_SYSEXIT;
}
return (psp);
}