Index: head/sys/kern/subr_syscall.c =================================================================== --- head/sys/kern/subr_syscall.c (revision 349870) +++ head/sys/kern/subr_syscall.c (revision 349871) @@ -1,235 +1,234 @@ /*- * SPDX-License-Identifier: BSD-4-Clause * * 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 #include #ifdef KTRACE #include #include #endif #include static inline int syscallenter(struct thread *td) { struct proc *p; struct syscall_args *sa; int error, traced; VM_CNT_INC(v_syscall); p = td->td_proc; sa = &td->td_sa; td->td_pticks = 0; if (__predict_false(td->td_cowgen != p->p_cowgen)) thread_cow_update(td); traced = (p->p_flag & P_TRACED) != 0; if (traced || td->td_dbgflags & TDB_USERWR) { PROC_LOCK(p); td->td_dbgflags &= ~TDB_USERWR; if (traced) td->td_dbgflags |= TDB_SCE; PROC_UNLOCK(p); } error = (p->p_sysent->sv_fetch_syscall_args)(td); #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) { + if (error != 0) + goto retval; - STOPEVENT(p, S_SCE, sa->narg); - if (p->p_flag & P_TRACED) { - PROC_LOCK(p); - if (p->p_ptevents & PTRACE_SCE) - ptracestop((td), SIGTRAP, NULL); - 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); + STOPEVENT(p, S_SCE, sa->narg); + if ((p->p_flag & P_TRACED) != 0) { + PROC_LOCK(p); + if (p->p_ptevents & PTRACE_SCE) + ptracestop((td), SIGTRAP, NULL); + PROC_UNLOCK(p); + } + if ((td->td_dbgflags & TDB_USERWR) != 0) { + /* + * Reread syscall number and arguments if debugger + * modified registers or memory. + */ + error = (p->p_sysent->sv_fetch_syscall_args)(td); #ifdef KTRACE - if (KTRPOINT(td, KTR_SYSCALL)) - ktrsyscall(sa->code, sa->narg, sa->args); + if (KTRPOINT(td, KTR_SYSCALL)) + ktrsyscall(sa->code, sa->narg, sa->args); #endif - if (error != 0) - goto retval; - } + 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; - } + /* + * 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; + error = syscall_thread_enter(td, sa->callp); + if (error != 0) + goto retval; #ifdef KDTRACE_HOOKS - /* Give the syscall:::entry DTrace probe a chance to fire. */ - if (__predict_false(systrace_enabled && - sa->callp->sy_entry != 0)) - (*systrace_probe_func)(sa, SYSTRACE_ENTRY, 0); + /* Give the syscall:::entry DTrace probe a chance to fire. */ + if (__predict_false(systrace_enabled && sa->callp->sy_entry != 0)) + (*systrace_probe_func)(sa, SYSTRACE_ENTRY, 0); #endif - AUDIT_SYSCALL_ENTER(sa->code, td); - error = (sa->callp->sy_call)(td, sa->args); - AUDIT_SYSCALL_EXIT(error, td); + 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; + /* Save the latest error return value. */ + if ((td->td_pflags & TDP_NERRNO) == 0) + td->td_errno = error; #ifdef KDTRACE_HOOKS - /* Give the syscall:::return DTrace probe a chance to fire. */ - if (__predict_false(systrace_enabled && - sa->callp->sy_return != 0)) - (*systrace_probe_func)(sa, SYSTRACE_RETURN, - error ? -1 : td->td_retval[0]); + /* Give the syscall:::return DTrace probe a chance to fire. */ + if (__predict_false(systrace_enabled && sa->callp->sy_return != 0)) + (*systrace_probe_func)(sa, SYSTRACE_RETURN, + error ? -1 : td->td_retval[0]); #endif - syscall_thread_exit(td, sa->callp); - } + 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 proc *p; struct syscall_args *sa; ksiginfo_t ksi; int traced, error1; KASSERT((td->td_pflags & TDP_FORKING) == 0, ("fork() did not clear TDP_FORKING upon completion")); p = td->td_proc; sa = &td->td_sa; if ((trap_enotcap || (p->p_flag2 & P2_TRAPCAP) != 0) && IN_CAPABILITY_MODE(td)) { error1 = (td->td_pflags & TDP_NERRNO) == 0 ? error : td->td_errno; if (error1 == ENOTCAPABLE || error1 == ECAPMODE) { ksiginfo_init_trap(&ksi); ksi.ksi_signo = SIGTRAP; ksi.ksi_errno = error1; ksi.ksi_code = TRAP_CAP; trapsignal(td, &ksi); } } /* * 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_ptevents & PTRACE_SCX) != 0)) ptracestop(td, SIGTRAP, NULL); td->td_dbgflags &= ~(TDB_SCX | TDB_EXEC | TDB_FORK); PROC_UNLOCK(p); } if (__predict_false(td->td_pflags & TDP_RFPPWAIT)) fork_rfppwait(td); }