Index: head/sys/kern/subr_syscall.c =================================================================== --- head/sys/kern/subr_syscall.c (revision 287869) +++ head/sys/kern/subr_syscall.c (revision 287870) @@ -1,251 +1,251 @@ /*- * Copyright (C) 1994, David Greenman * Copyright (c) 1990, 1993 * The Regents of the University of California. All rights reserved. * Copyright (C) 2010 Konstantin Belousov * * This code is derived from software contributed to Berkeley by * the University of Utah, and William Jolitz. * * 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 "opt_capsicum.h" #include "opt_ktrace.h" __FBSDID("$FreeBSD$"); #include #include #ifdef KTRACE #include #include #endif #include static inline 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_pticks = 0; if (td->td_cowgen != p->p_cowgen) thread_cow_update(td); - if (p->p_flag & P_TRACED) { - traced = 1; + traced = (p->p_flag & P_TRACED) != 0; + if (traced || td->td_dbgflags & TDB_USERWR) { PROC_LOCK(p); td->td_dbgflags &= ~TDB_USERWR; - td->td_dbgflags |= TDB_SCE; + if (traced) + 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 KTR_START4(KTR_SYSC, "syscall", syscallname(p, sa->code), (uintptr_t)td, "pid:%d", td->td_proc->p_pid, "arg0:%p", sa->args[0], "arg1:%p", sa->args[1], "arg2:%p", sa->args[2]); if (error == 0) { STOPEVENT(p, S_SCE, sa->narg); if (p->p_flag & P_TRACED && p->p_stops & S_PT_SCE) { PROC_LOCK(p); td->td_dbg_sc_code = sa->code; td->td_dbg_sc_narg = sa->narg; ptracestop((td), SIGTRAP); PROC_UNLOCK(p); } 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); PROC_LOCK(p); td->td_dbg_sc_code = sa->code; td->td_dbg_sc_narg = sa->narg; PROC_UNLOCK(p); #ifdef KTRACE if (KTRPOINT(td, KTR_SYSCALL)) ktrsyscall(sa->code, sa->narg, sa->args); #endif if (error != 0) goto retval; } #ifdef CAPABILITY_MODE /* * In capability mode, we only allow access to system calls * flagged with SYF_CAPENABLED. */ if (IN_CAPABILITY_MODE(td) && !(sa->callp->sy_flags & SYF_CAPENABLED)) { error = ECAPMODE; goto retval; } #endif 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, 0); #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. */ if ((td->td_pflags & TDP_NERRNO) == 0) 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, NULL, (error) ? -1 : td->td_retval[0]); #endif syscall_thread_exit(td, sa->callp); } retval: KTR_STOP4(KTR_SYSC, "syscall", syscallname(p, sa->code), (uintptr_t)td, "pid:%d", td->td_proc->p_pid, "error:%d", error, "retval0:%#lx", td->td_retval[0], "retval1:%#lx", td->td_retval[1]); if (traced) { PROC_LOCK(p); td->td_dbgflags &= ~TDB_SCE; PROC_UNLOCK(p); } (p->p_sysent->sv_set_syscall_retval)(td, error); return (error); } static inline void syscallret(struct thread *td, int error, struct syscall_args *sa) { struct proc *p, *p2; int traced; p = td->td_proc; /* * Handle reschedule and other end-of-syscall issues */ userret(td, td->td_frame); #ifdef KTRACE if (KTRPOINT(td, KTR_SYSRET)) { ktrsysret(sa->code, (td->td_pflags & TDP_NERRNO) == 0 ? error : td->td_errno, td->td_retval[0]); } #endif td->td_pflags &= ~TDP_NERRNO; 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); if (traced || (td->td_dbgflags & (TDB_EXEC | TDB_FORK)) != 0) { PROC_LOCK(p); /* * If tracing the execed process, trap to the debugger * so that breakpoints can be set before the program * executes. If debugger requested tracing of syscall * returns, do it now too. */ if (traced && ((td->td_dbgflags & (TDB_FORK | TDB_EXEC)) != 0 || (p->p_stops & S_PT_SCX) != 0)) ptracestop(td, SIGTRAP); td->td_dbgflags &= ~(TDB_SCX | TDB_EXEC | TDB_FORK); PROC_UNLOCK(p); } if (td->td_pflags & TDP_RFPPWAIT) { /* * Preserve synchronization semantics of vfork. If * waiting for child to exec or exit, fork set * P_PPWAIT on child, and there we sleep on our proc * (in case of exit). * * Do it after the ptracestop() above is finished, to * not block our debugger until child execs or exits * to finish vfork wait. */ td->td_pflags &= ~TDP_RFPPWAIT; p2 = td->td_rfppwait_p; again: PROC_LOCK(p2); while (p2->p_flag & P_PPWAIT) { PROC_LOCK(p); if (thread_suspend_check_needed()) { PROC_UNLOCK(p2); thread_suspend_check(0); PROC_UNLOCK(p); goto again; } else { PROC_UNLOCK(p); } cv_timedwait(&p2->p_pwait, &p2->p_mtx, hz); } PROC_UNLOCK(p2); } }