/* $NetBSD: syscall.c,v 1.57 2008/10/21 12:16:59 ad Exp $ */ /*- * Copyright (c) 1998, 2000 The NetBSD Foundation, Inc. * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation * by Charles M. Hannum. * * 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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> __KERNEL_RCSID(0, "$NetBSD: syscall.c,v 1.57 2008/10/21 12:16:59 ad Exp $"); #include "opt_vm86.h" #include "opt_sa.h" #include <sys/param.h> #include <sys/systm.h> #include <sys/proc.h> #include <sys/user.h> #include <sys/signal.h> #include <sys/ktrace.h> #include <sys/sa.h> #include <sys/savar.h> #include <sys/syscall.h> #include <sys/syscallvar.h> #include <sys/syscall_stats.h> #include <uvm/uvm_extern.h> #include <machine/cpu.h> #include <machine/psl.h> #include <machine/userret.h> void syscall(struct trapframe *); int x86_copyargs(void *, void *, size_t); #ifdef VM86 void syscall_vm86(struct trapframe *); #endif void syscall_intern(p) struct proc *p; { p->p_md.md_syscall = syscall; } /* * syscall(frame): * System call request from POSIX system call gate interface to kernel. * Like trap(), argument is call by reference. */ void syscall(struct trapframe *frame) { const struct sysent *callp; struct lwp *l; int error; register_t code, args[2 + SYS_MAXSYSARGS], rval[2]; l = curlwp; LWP_CACHE_CREDS(l, l->l_proc); code = frame->tf_eax & (SYS_NSYSENT - 1); callp = l->l_proc->p_emul->e_sysent + code; SYSCALL_COUNT(syscall_counts, code); SYSCALL_TIME_SYS_ENTRY(l, syscall_times, code); #ifdef KERN_SA if (__predict_false((l->l_savp) && (l->l_savp->savp_pflags & SAVP_FLAG_DELIVERING))) l->l_savp->savp_pflags &= ~SAVP_FLAG_DELIVERING; #endif if (callp->sy_argsize) { error = x86_copyargs((char *)frame->tf_esp + sizeof(int), args, callp->sy_argsize); if (__predict_false(error != 0)) goto bad; } if (!__predict_false(l->l_proc->p_trace_enabled) || __predict_false(callp->sy_flags & SYCALL_INDIRECT) || (error = trace_enter(frame->tf_eax & (SYS_NSYSENT - 1), args, callp->sy_narg)) == 0) { rval[0] = 0; rval[1] = 0; KASSERT(l->l_holdcnt == 0); error = sy_call(callp, l, args, rval); } if (__predict_false(l->l_proc->p_trace_enabled) && !__predict_false(callp->sy_flags & SYCALL_INDIRECT)) { code = frame->tf_eax & (SYS_NSYSENT - 1); trace_exit(code, rval, error); } if (__predict_true(error == 0)) { frame->tf_eax = rval[0]; frame->tf_edx = rval[1]; frame->tf_eflags &= ~PSL_C; /* carry bit */ } else { switch (error) { case ERESTART: /* * The offset to adjust the PC by depends on whether we * entered the kernel through the trap or call gate. * We saved the instruction size in tf_err on entry. */ frame->tf_eip -= frame->tf_err; break; case EJUSTRETURN: /* nothing to do */ break; default: bad: frame->tf_eax = error; frame->tf_eflags |= PSL_C; /* carry bit */ break; } } SYSCALL_TIME_SYS_EXIT(l); userret(l); } #ifdef VM86 void syscall_vm86(frame) struct trapframe *frame; { struct lwp *l; struct proc *p; ksiginfo_t ksi; KSI_INIT_TRAP(&ksi); ksi.ksi_signo = SIGBUS; ksi.ksi_code = BUS_OBJERR; ksi.ksi_trap = T_PROTFLT; ksi.ksi_addr = (void *)frame->tf_eip; l = curlwp; p = l->l_proc; #ifdef KERN_SA /* While this is probably not needed, it's probably better to include than not */ if (__predict_false((l->l_savp) && (l->l_savp->savp_pflags & SAVP_FLAG_DELIVERING))) l->l_savp->savp_pflags &= ~SAVP_FLAG_DELIVERING; #endif (*p->p_emul->e_trapsignal)(l, &ksi); userret(l); } #endif void child_return(arg) void *arg; { struct lwp *l = arg; struct trapframe *tf = l->l_md.md_regs; tf->tf_eax = 0; tf->tf_eflags &= ~PSL_C; userret(l); ktrsysret(SYS_fork, 0, 0); }