1 /* $NetBSD: linux_syscall.c,v 1.29 2008/10/21 12:16:59 ad Exp $ */ 2 3 /*- 4 * Copyright (c) 1998, 2000 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Charles M. Hannum. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 #include <sys/cdefs.h> 33 __KERNEL_RCSID(0, "$NetBSD: linux_syscall.c,v 1.29 2008/10/21 12:16:59 ad Exp $"); 34 35 #if defined(_KERNEL_OPT) 36 #include "opt_compat_linux.h" 37 #endif 38 39 #include <sys/param.h> 40 #include <sys/systm.h> 41 #include <sys/proc.h> 42 #include <sys/user.h> 43 #include <sys/signal.h> 44 #include <sys/syscall.h> 45 #include <sys/syscallvar.h> 46 47 #include <uvm/uvm_extern.h> 48 49 #include <machine/cpu.h> 50 #include <machine/psl.h> 51 #include <machine/userret.h> 52 53 #include <compat/linux/linux_syscall.h> 54 #include <compat/linux/common/linux_types.h> 55 #include <compat/linux/common/linux_errno.h> 56 #include <compat/linux/common/linux_signal.h> 57 #include <compat/linux/common/linux_siginfo.h> 58 #include <compat/linux/arch/amd64/linux_siginfo.h> 59 #include <compat/linux/arch/amd64/linux_machdep.h> 60 61 void linux_syscall_intern(struct proc *); 62 static void linux_syscall(struct trapframe *); 63 64 void 65 linux_syscall_intern(struct proc *p) 66 { 67 68 p->p_md.md_syscall = linux_syscall; 69 } 70 71 /* 72 * syscall(frame): 73 * System call request from POSIX system call gate interface to kernel. 74 * Like trap(), argument is call by reference. 75 */ 76 static void 77 linux_syscall(struct trapframe *frame) 78 { 79 const struct sysent *callp; 80 struct proc *p; 81 struct lwp *l; 82 int error; 83 register_t code, rval[2]; 84 #define args (&frame->tf_rdi) 85 86 l = curlwp; 87 p = l->l_proc; 88 89 code = frame->tf_rax; 90 91 LWP_CACHE_CREDS(l, p); 92 93 callp = p->p_emul->e_sysent; 94 95 code &= (LINUX_SYS_NSYSENT - 1); 96 callp += code; 97 98 /* 99 * Linux system calls have a maximum of 6 arguments, they are 100 * already adjacent in the syscall trapframe. 101 */ 102 103 if (__predict_false(p->p_trace_enabled) 104 && (error = trace_enter(code, args, callp->sy_narg)) != 0) 105 goto out; 106 107 rval[0] = 0; 108 rval[1] = 0; 109 error = sy_call(callp, l, args, rval); 110 out: 111 switch (error) { 112 case 0: 113 frame->tf_rax = rval[0]; 114 break; 115 case ERESTART: 116 /* 117 * The offset to adjust the PC by depends on whether we entered 118 * the kernel through the trap or call gate. We pushed the 119 * size of the instruction into tf_err on entry. 120 */ 121 frame->tf_rip -= frame->tf_err; 122 break; 123 case EJUSTRETURN: 124 /* nothing to do */ 125 break; 126 default: 127 error = native_to_linux_errno[error]; 128 frame->tf_rax = error; 129 break; 130 } 131 132 if (__predict_false(p->p_trace_enabled)) 133 trace_exit(code, rval, error); 134 135 userret(l); 136 } 137