402 lines
11 KiB
C
402 lines
11 KiB
C
/*-
|
|
* Copyright (C) 1994, David Greenman
|
|
* Copyright (c) 1990, 1993
|
|
* The Regents of the University of California. All rights reserved.
|
|
* Copyright (c) 2007 The FreeBSD Foundation
|
|
*
|
|
* This code is derived from software contributed to Berkeley by
|
|
* the University of Utah, and William Jolitz.
|
|
*
|
|
* Portions of this software were developed by A. Joseph Koshy under
|
|
* sponsorship from the FreeBSD Foundation and Google, Inc.
|
|
*
|
|
* 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.
|
|
*
|
|
* from: @(#)trap.c 7.4 (Berkeley) 5/13/91
|
|
*/
|
|
|
|
#include <sys/cdefs.h>
|
|
__FBSDID("$FreeBSD$");
|
|
|
|
#include "opt_ktrace.h"
|
|
#include "opt_kdtrace.h"
|
|
#include "opt_sched.h"
|
|
|
|
#include <sys/param.h>
|
|
#include <sys/bus.h>
|
|
#include <sys/kernel.h>
|
|
#include <sys/lock.h>
|
|
#include <sys/mutex.h>
|
|
#include <sys/pmckern.h>
|
|
#include <sys/proc.h>
|
|
#include <sys/ktr.h>
|
|
#include <sys/pioctl.h>
|
|
#include <sys/ptrace.h>
|
|
#include <sys/resourcevar.h>
|
|
#include <sys/sched.h>
|
|
#include <sys/signalvar.h>
|
|
#include <sys/syscall.h>
|
|
#include <sys/syscallsubr.h>
|
|
#include <sys/sysent.h>
|
|
#include <sys/systm.h>
|
|
#include <sys/vmmeter.h>
|
|
#ifdef KTRACE
|
|
#include <sys/uio.h>
|
|
#include <sys/ktrace.h>
|
|
#endif
|
|
#include <security/audit/audit.h>
|
|
|
|
#include <machine/cpu.h>
|
|
|
|
#ifdef XEN
|
|
#include <vm/vm.h>
|
|
#include <vm/vm_param.h>
|
|
#include <vm/pmap.h>
|
|
#endif
|
|
|
|
#include <security/mac/mac_framework.h>
|
|
|
|
/*
|
|
* Define the code needed before returning to user mode, for trap and
|
|
* syscall.
|
|
*/
|
|
void
|
|
userret(struct thread *td, struct trapframe *frame)
|
|
{
|
|
struct proc *p = td->td_proc;
|
|
|
|
CTR3(KTR_SYSC, "userret: thread %p (pid %d, %s)", td, p->p_pid,
|
|
td->td_name);
|
|
#if 0
|
|
#ifdef DIAGNOSTIC
|
|
/* Check that we called signotify() enough. */
|
|
PROC_LOCK(p);
|
|
thread_lock(td);
|
|
if (SIGPENDING(td) && ((td->td_flags & TDF_NEEDSIGCHK) == 0 ||
|
|
(td->td_flags & TDF_ASTPENDING) == 0))
|
|
printf("failed to set signal flags properly for ast()\n");
|
|
thread_unlock(td);
|
|
PROC_UNLOCK(p);
|
|
#endif
|
|
#endif
|
|
#ifdef KTRACE
|
|
KTRUSERRET(td);
|
|
#endif
|
|
/*
|
|
* If this thread tickled GEOM, we need to wait for the giggling to
|
|
* stop before we return to userland
|
|
*/
|
|
if (td->td_pflags & TDP_GEOM)
|
|
g_waitidle();
|
|
|
|
/*
|
|
* Charge system time if profiling.
|
|
*/
|
|
if (p->p_flag & P_PROFIL) {
|
|
addupc_task(td, TRAPF_PC(frame), td->td_pticks * psratio);
|
|
}
|
|
/*
|
|
* Let the scheduler adjust our priority etc.
|
|
*/
|
|
sched_userret(td);
|
|
KASSERT(td->td_locks == 0,
|
|
("userret: Returning with %d locks held.", td->td_locks));
|
|
#ifdef XEN
|
|
PT_UPDATES_FLUSH();
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
* Process an asynchronous software trap.
|
|
* This is relatively easy.
|
|
* This function will return with preemption disabled.
|
|
*/
|
|
void
|
|
ast(struct trapframe *framep)
|
|
{
|
|
struct thread *td;
|
|
struct proc *p;
|
|
int flags;
|
|
int sig;
|
|
|
|
td = curthread;
|
|
p = td->td_proc;
|
|
|
|
CTR3(KTR_SYSC, "ast: thread %p (pid %d, %s)", td, p->p_pid,
|
|
p->p_comm);
|
|
KASSERT(TRAPF_USERMODE(framep), ("ast in kernel mode"));
|
|
WITNESS_WARN(WARN_PANIC, NULL, "Returning to user mode");
|
|
mtx_assert(&Giant, MA_NOTOWNED);
|
|
THREAD_LOCK_ASSERT(td, MA_NOTOWNED);
|
|
td->td_frame = framep;
|
|
td->td_pticks = 0;
|
|
|
|
/*
|
|
* This updates the td_flag's for the checks below in one
|
|
* "atomic" operation with turning off the astpending flag.
|
|
* If another AST is triggered while we are handling the
|
|
* AST's saved in flags, the astpending flag will be set and
|
|
* ast() will be called again.
|
|
*/
|
|
thread_lock(td);
|
|
flags = td->td_flags;
|
|
td->td_flags &= ~(TDF_ASTPENDING | TDF_NEEDSIGCHK | TDF_NEEDSUSPCHK |
|
|
TDF_NEEDRESCHED | TDF_ALRMPEND | TDF_PROFPEND | TDF_MACPEND);
|
|
thread_unlock(td);
|
|
PCPU_INC(cnt.v_trap);
|
|
|
|
if (td->td_ucred != p->p_ucred)
|
|
cred_update_thread(td);
|
|
if (td->td_pflags & TDP_OWEUPC && p->p_flag & P_PROFIL) {
|
|
addupc_task(td, td->td_profil_addr, td->td_profil_ticks);
|
|
td->td_profil_ticks = 0;
|
|
td->td_pflags &= ~TDP_OWEUPC;
|
|
}
|
|
if (flags & TDF_ALRMPEND) {
|
|
PROC_LOCK(p);
|
|
psignal(p, SIGVTALRM);
|
|
PROC_UNLOCK(p);
|
|
}
|
|
if (flags & TDF_PROFPEND) {
|
|
PROC_LOCK(p);
|
|
psignal(p, SIGPROF);
|
|
PROC_UNLOCK(p);
|
|
}
|
|
#ifdef MAC
|
|
if (flags & TDF_MACPEND)
|
|
mac_thread_userret(td);
|
|
#endif
|
|
if (flags & TDF_NEEDRESCHED) {
|
|
#ifdef KTRACE
|
|
if (KTRPOINT(td, KTR_CSW))
|
|
ktrcsw(1, 1);
|
|
#endif
|
|
thread_lock(td);
|
|
sched_prio(td, td->td_user_pri);
|
|
mi_switch(SW_INVOL | SWT_NEEDRESCHED, NULL);
|
|
thread_unlock(td);
|
|
#ifdef KTRACE
|
|
if (KTRPOINT(td, KTR_CSW))
|
|
ktrcsw(0, 1);
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
* Check for signals. Unlocked reads of p_pendingcnt or
|
|
* p_siglist might cause process-directed signal to be handled
|
|
* later.
|
|
*/
|
|
if (flags & TDF_NEEDSIGCHK || p->p_pendingcnt > 0 ||
|
|
!SIGISEMPTY(p->p_siglist)) {
|
|
PROC_LOCK(p);
|
|
mtx_lock(&p->p_sigacts->ps_mtx);
|
|
while ((sig = cursig(td, SIG_STOP_ALLOWED)) != 0)
|
|
postsig(sig);
|
|
mtx_unlock(&p->p_sigacts->ps_mtx);
|
|
PROC_UNLOCK(p);
|
|
}
|
|
/*
|
|
* We need to check to see if we have to exit or wait due to a
|
|
* single threading requirement or some other STOP condition.
|
|
*/
|
|
if (flags & TDF_NEEDSUSPCHK) {
|
|
PROC_LOCK(p);
|
|
thread_suspend_check(0);
|
|
PROC_UNLOCK(p);
|
|
}
|
|
|
|
if (td->td_pflags & TDP_OLDMASK) {
|
|
td->td_pflags &= ~TDP_OLDMASK;
|
|
kern_sigprocmask(td, SIG_SETMASK, &td->td_oldsigmask, NULL, 0);
|
|
}
|
|
|
|
userret(td, framep);
|
|
mtx_assert(&Giant, MA_NOTOWNED);
|
|
}
|
|
|
|
#ifdef HAVE_SYSCALL_ARGS_DEF
|
|
const char *
|
|
syscallname(struct proc *p, u_int code)
|
|
{
|
|
static const char unknown[] = "unknown";
|
|
|
|
if (p->p_sysent->sv_syscallnames == NULL)
|
|
return (unknown);
|
|
return (p->p_sysent->sv_syscallnames[code]);
|
|
}
|
|
|
|
int
|
|
syscallenter(struct thread *td, struct syscall_args *sa)
|
|
{
|
|
struct proc *p;
|
|
int error, traced;
|
|
|
|
PCPU_INC(cnt.v_syscall);
|
|
p = td->td_proc;
|
|
td->td_syscalls++;
|
|
|
|
td->td_pticks = 0;
|
|
if (td->td_ucred != p->p_ucred)
|
|
cred_update_thread(td);
|
|
if (p->p_flag & P_TRACED) {
|
|
traced = 1;
|
|
PROC_LOCK(p);
|
|
td->td_dbgflags &= ~TDB_USERWR;
|
|
td->td_dbgflags |= TDB_SCE;
|
|
PROC_UNLOCK(p);
|
|
} else
|
|
traced = 0;
|
|
error = (p->p_sysent->sv_fetch_syscall_args)(td, sa);
|
|
#ifdef KTRACE
|
|
if (KTRPOINT(td, KTR_SYSCALL))
|
|
ktrsyscall(sa->code, sa->narg, sa->args);
|
|
#endif
|
|
|
|
CTR6(KTR_SYSC,
|
|
"syscall: td=%p pid %d %s (%#lx, %#lx, %#lx)",
|
|
td, td->td_proc->p_pid, syscallname(p, sa->code),
|
|
sa->args[0], sa->args[1], sa->args[2]);
|
|
|
|
if (error == 0) {
|
|
STOPEVENT(p, S_SCE, sa->narg);
|
|
PTRACESTOP_SC(p, td, S_PT_SCE);
|
|
if (td->td_dbgflags & TDB_USERWR) {
|
|
/*
|
|
* Reread syscall number and arguments if
|
|
* debugger modified registers or memory.
|
|
*/
|
|
error = (p->p_sysent->sv_fetch_syscall_args)(td, sa);
|
|
#ifdef KTRACE
|
|
if (KTRPOINT(td, KTR_SYSCALL))
|
|
ktrsyscall(sa->code, sa->narg, sa->args);
|
|
#endif
|
|
if (error != 0)
|
|
goto retval;
|
|
}
|
|
error = syscall_thread_enter(td, sa->callp);
|
|
if (error != 0)
|
|
goto retval;
|
|
|
|
#ifdef KDTRACE_HOOKS
|
|
/*
|
|
* If the systrace module has registered it's probe
|
|
* callback and if there is a probe active for the
|
|
* syscall 'entry', process the probe.
|
|
*/
|
|
if (systrace_probe_func != NULL && sa->callp->sy_entry != 0)
|
|
(*systrace_probe_func)(sa->callp->sy_entry, sa->code,
|
|
sa->callp, sa->args);
|
|
#endif
|
|
|
|
AUDIT_SYSCALL_ENTER(sa->code, td);
|
|
error = (sa->callp->sy_call)(td, sa->args);
|
|
AUDIT_SYSCALL_EXIT(error, td);
|
|
|
|
/* Save the latest error return value. */
|
|
td->td_errno = error;
|
|
|
|
#ifdef KDTRACE_HOOKS
|
|
/*
|
|
* If the systrace module has registered it's probe
|
|
* callback and if there is a probe active for the
|
|
* syscall 'return', process the probe.
|
|
*/
|
|
if (systrace_probe_func != NULL && sa->callp->sy_return != 0)
|
|
(*systrace_probe_func)(sa->callp->sy_return, sa->code,
|
|
sa->callp, sa->args);
|
|
#endif
|
|
syscall_thread_exit(td, sa->callp);
|
|
CTR4(KTR_SYSC, "syscall: p=%p error=%d return %#lx %#lx",
|
|
p, error, td->td_retval[0], td->td_retval[1]);
|
|
}
|
|
retval:
|
|
if (traced) {
|
|
PROC_LOCK(p);
|
|
td->td_dbgflags &= ~TDB_SCE;
|
|
PROC_UNLOCK(p);
|
|
}
|
|
(p->p_sysent->sv_set_syscall_retval)(td, error);
|
|
return (error);
|
|
}
|
|
|
|
void
|
|
syscallret(struct thread *td, int error, struct syscall_args *sa __unused)
|
|
{
|
|
struct proc *p;
|
|
int traced;
|
|
|
|
p = td->td_proc;
|
|
|
|
/*
|
|
* Check for misbehavior.
|
|
*/
|
|
WITNESS_WARN(WARN_PANIC, NULL, "System call %s returning",
|
|
syscallname(p, sa->code));
|
|
KASSERT(td->td_critnest == 0,
|
|
("System call %s returning in a critical section",
|
|
syscallname(p, sa->code)));
|
|
KASSERT(td->td_locks == 0,
|
|
("System call %s returning with %d locks held",
|
|
syscallname(p, sa->code), td->td_locks));
|
|
|
|
/*
|
|
* Handle reschedule and other end-of-syscall issues
|
|
*/
|
|
userret(td, td->td_frame);
|
|
|
|
CTR4(KTR_SYSC, "syscall %s exit thread %p pid %d proc %s",
|
|
syscallname(p, sa->code), td, td->td_proc->p_pid, td->td_name);
|
|
|
|
#ifdef KTRACE
|
|
if (KTRPOINT(td, KTR_SYSRET))
|
|
ktrsysret(sa->code, error, td->td_retval[0]);
|
|
#endif
|
|
|
|
if (p->p_flag & P_TRACED) {
|
|
traced = 1;
|
|
PROC_LOCK(p);
|
|
td->td_dbgflags |= TDB_SCX;
|
|
PROC_UNLOCK(p);
|
|
} else
|
|
traced = 0;
|
|
/*
|
|
* This works because errno is findable through the
|
|
* register set. If we ever support an emulation where this
|
|
* is not the case, this code will need to be revisited.
|
|
*/
|
|
STOPEVENT(p, S_SCX, sa->code);
|
|
PTRACESTOP_SC(p, td, S_PT_SCX);
|
|
if (traced || (td->td_dbgflags & TDB_EXEC) != 0) {
|
|
PROC_LOCK(p);
|
|
td->td_dbgflags &= ~(TDB_SCX | TDB_EXEC);
|
|
PROC_UNLOCK(p);
|
|
}
|
|
}
|
|
#endif /* HAVE_SYSCALL_ARGS_DEF */
|