1 /* $NetBSD: linux_syscall.c,v 1.32 2015/03/07 18:41:40 christos 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 1.32 2015/03/07 18:41:40 christos 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/signal.h> 43 #include <sys/syscall.h> 44 #include <sys/syscallvar.h> 45 46 #include <machine/cpu.h> 47 #include <machine/psl.h> 48 #include <machine/userret.h> 49 50 #include <compat/linux/linux_syscall.h> 51 #include <compat/linux/common/linux_types.h> 52 #include <compat/linux/common/linux_errno.h> 53 #include <compat/linux/common/linux_signal.h> 54 #include <compat/linux/common/linux_siginfo.h> 55 #include <compat/linux/arch/amd64/linux_siginfo.h> 56 #include <compat/linux/arch/amd64/linux_machdep.h> 57 58 void linux_syscall_intern(struct proc *); 59 static void linux_syscall(struct trapframe *); 60 61 void 62 linux_syscall_intern(struct proc *p) 63 { 64 65 p->p_md.md_syscall = linux_syscall; 66 } 67 68 /* 69 * syscall(frame): 70 * System call request from POSIX system call gate interface to kernel. 71 * Like trap(), argument is call by reference. 72 */ 73 static void 74 linux_syscall(struct trapframe *frame) 75 { 76 const struct sysent *callp; 77 struct proc *p; 78 struct lwp *l; 79 int error; 80 register_t code, rval[2]; 81 #define args (&frame->tf_rdi) 82 83 l = curlwp; 84 p = l->l_proc; 85 86 code = frame->tf_rax; 87 88 LWP_CACHE_CREDS(l, p); 89 90 callp = p->p_emul->e_sysent; 91 92 code &= (LINUX_SYS_NSYSENT - 1); 93 callp += code; 94 95 /* 96 * Linux system calls have a maximum of 6 arguments, they are 97 * already adjacent in the syscall trapframe. 98 */ 99 100 if (__predict_false(p->p_trace_enabled || KDTRACE_ENTRY(callp->sy_entry)) 101 && (error = trace_enter(code, callp, args)) != 0) 102 goto out; 103 104 rval[0] = 0; 105 rval[1] = 0; 106 error = sy_call(callp, l, args, rval); 107 out: 108 switch (error) { 109 case 0: 110 frame->tf_rax = rval[0]; 111 break; 112 case ERESTART: 113 /* 114 * The offset to adjust the PC by depends on whether we entered 115 * the kernel through the trap or call gate. We pushed the 116 * size of the instruction into tf_err on entry. 117 */ 118 frame->tf_rip -= frame->tf_err; 119 break; 120 case EJUSTRETURN: 121 /* nothing to do */ 122 break; 123 default: 124 error = native_to_linux_errno[error]; 125 frame->tf_rax = error; 126 break; 127 } 128 129 if (__predict_false(p->p_trace_enabled || KDTRACE_ENTRY(callp->sy_return))) 130 trace_exit(code, callp, args, rval, error); 131 132 userret(l); 133 } 134