1/*- 2 * Copyright (C) 1994, David Greenman 3 * Copyright (c) 1990, 1993 4 * The Regents of the University of California. All rights reserved. 5 * 6 * This code is derived from software contributed to Berkeley by 7 * the University of Utah, and William Jolitz. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. All advertising materials mentioning features or use of this software 18 * must display the following acknowledgement: 19 * This product includes software developed by the University of 20 * California, Berkeley and its contributors. 21 * 4. Neither the name of the University nor the names of its contributors 22 * may be used to endorse or promote products derived from this software 23 * without specific prior written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 28 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 35 * SUCH DAMAGE. 36 */ 37 38#include <sys/cdefs.h> 39__FBSDID("$FreeBSD: stable/11/sys/amd64/ia32/ia32_syscall.c 332428 2018-04-12 13:40:02Z kib $"); 40 41/* 42 * 386 Trap and System call handling 43 */ 44 45#include "opt_clock.h" 46#include "opt_compat.h" 47#include "opt_cpu.h" 48#include "opt_isa.h" 49 50#include <sys/param.h> 51#include <sys/bus.h> 52#include <sys/systm.h> 53#include <sys/proc.h> 54#include <sys/pioctl.h> 55#include <sys/kernel.h> 56#include <sys/ktr.h> 57#include <sys/lock.h> 58#include <sys/mutex.h> 59#include <sys/proc.h> 60#include <sys/ptrace.h> 61#include <sys/resourcevar.h> 62#include <sys/signalvar.h> 63#include <sys/syscall.h> 64#include <sys/sysctl.h> 65#include <sys/sysent.h> 66#include <sys/uio.h> 67#include <sys/vmmeter.h> 68#include <security/audit/audit.h> 69 70#include <vm/vm.h> 71#include <vm/vm_param.h> 72#include <vm/pmap.h> 73#include <vm/vm_kern.h> 74#include <vm/vm_map.h> 75#include <vm/vm_page.h> 76#include <vm/vm_extern.h> 77 78#include <machine/cpu.h> 79#include <machine/intr_machdep.h> 80#include <machine/md_var.h> 81 82#include <compat/freebsd32/freebsd32_signal.h> 83#include <compat/freebsd32/freebsd32_util.h> 84#include <compat/ia32/ia32_signal.h> 85#include <machine/psl.h> 86#include <machine/segments.h> 87#include <machine/specialreg.h> 88#include <machine/sysarch.h> 89#include <machine/frame.h> 90#include <machine/md_var.h> 91#include <machine/pcb.h> 92#include <machine/cpufunc.h> 93 94#define IDTVEC(name) __CONCAT(X,name) 95 96extern inthand_t IDTVEC(int0x80_syscall), IDTVEC(int0x80_syscall_pti), 97 IDTVEC(rsvd), IDTVEC(rsvd_pti); 98 99void ia32_syscall(struct trapframe *frame); /* Called from asm code */ 100 101void 102ia32_set_syscall_retval(struct thread *td, int error) 103{ 104 105 cpu_set_syscall_retval(td, error); 106} 107 108int 109ia32_fetch_syscall_args(struct thread *td) 110{ 111 struct proc *p; 112 struct trapframe *frame; 113 struct syscall_args *sa; 114 caddr_t params; 115 u_int32_t args[8], tmp; 116 int error, i; 117#ifdef COMPAT_43 118 u_int32_t eip; 119 int cs; 120#endif 121 122 p = td->td_proc; 123 frame = td->td_frame; 124 sa = &td->td_sa; 125 126#ifdef COMPAT_43 127 if (__predict_false(frame->tf_cs == 7 && frame->tf_rip == 2)) { 128 /* 129 * In lcall $7,$0 after int $0x80. Convert the user 130 * frame to what it would be for a direct int 0x80 instead 131 * of lcall $7,$0, by popping the lcall return address. 132 */ 133 error = fueword32((void *)frame->tf_rsp, &eip); 134 if (error == -1) 135 return (EFAULT); 136 cs = fuword16((void *)(frame->tf_rsp + sizeof(u_int32_t))); 137 if (cs == -1) 138 return (EFAULT); 139 140 /* 141 * Unwind in-kernel frame after all stack frame pieces 142 * were successfully read. 143 */ 144 frame->tf_rip = eip; 145 frame->tf_cs = cs; 146 frame->tf_rsp += 2 * sizeof(u_int32_t); 147 frame->tf_err = 7; /* size of lcall $7,$0 */ 148 } 149#endif 150 151 params = (caddr_t)frame->tf_rsp + sizeof(u_int32_t); 152 sa->code = frame->tf_rax; 153 154 /* 155 * Need to check if this is a 32 bit or 64 bit syscall. 156 */ 157 if (sa->code == SYS_syscall) { 158 /* 159 * Code is first argument, followed by actual args. 160 */ 161 error = fueword32(params, &tmp); 162 if (error == -1) 163 return (EFAULT); 164 sa->code = tmp; 165 params += sizeof(int); 166 } else if (sa->code == SYS___syscall) { 167 /* 168 * Like syscall, but code is a quad, so as to maintain 169 * quad alignment for the rest of the arguments. 170 * We use a 32-bit fetch in case params is not 171 * aligned. 172 */ 173 error = fueword32(params, &tmp); 174 if (error == -1) 175 return (EFAULT); 176 sa->code = tmp; 177 params += sizeof(quad_t); 178 } 179 if (p->p_sysent->sv_mask) 180 sa->code &= p->p_sysent->sv_mask; 181 if (sa->code >= p->p_sysent->sv_size) 182 sa->callp = &p->p_sysent->sv_table[0]; 183 else 184 sa->callp = &p->p_sysent->sv_table[sa->code]; 185 sa->narg = sa->callp->sy_narg; 186 187 if (params != NULL && sa->narg != 0) 188 error = copyin(params, (caddr_t)args, 189 (u_int)(sa->narg * sizeof(int))); 190 else 191 error = 0; 192 193 for (i = 0; i < sa->narg; i++) 194 sa->args[i] = args[i]; 195 196 if (error == 0) { 197 td->td_retval[0] = 0; 198 td->td_retval[1] = frame->tf_rdx; 199 } 200 201 return (error); 202} 203 204#include "../../kern/subr_syscall.c" 205 206void 207ia32_syscall(struct trapframe *frame) 208{ 209 struct thread *td; 210 register_t orig_tf_rflags; 211 int error; 212 ksiginfo_t ksi; 213 214 orig_tf_rflags = frame->tf_rflags; 215 td = curthread; 216 td->td_frame = frame; 217 218 error = syscallenter(td); 219 220 /* 221 * Traced syscall. 222 */ 223 if (orig_tf_rflags & PSL_T) { 224 frame->tf_rflags &= ~PSL_T; 225 ksiginfo_init_trap(&ksi); 226 ksi.ksi_signo = SIGTRAP; 227 ksi.ksi_code = TRAP_TRACE; 228 ksi.ksi_addr = (void *)frame->tf_rip; 229 trapsignal(td, &ksi); 230 } 231 232 syscallret(td, error); 233} 234 235static void 236ia32_syscall_enable(void *dummy) 237{ 238 239 setidt(IDT_SYSCALL, pti ? &IDTVEC(int0x80_syscall_pti) : 240 &IDTVEC(int0x80_syscall), SDT_SYSIGT, SEL_UPL, 0); 241} 242 243static void 244ia32_syscall_disable(void *dummy) 245{ 246 247 setidt(IDT_SYSCALL, pti ? &IDTVEC(rsvd_pti) : &IDTVEC(rsvd), 248 SDT_SYSIGT, SEL_KPL, 0); 249} 250 251SYSINIT(ia32_syscall, SI_SUB_EXEC, SI_ORDER_ANY, ia32_syscall_enable, NULL); 252SYSUNINIT(ia32_syscall, SI_SUB_EXEC, SI_ORDER_ANY, ia32_syscall_disable, NULL); 253 254#ifdef COMPAT_43 255int 256setup_lcall_gate(void) 257{ 258 struct i386_ldt_args uap; 259 struct user_segment_descriptor desc; 260 uint32_t lcall_addr; 261 int error; 262 263 bzero(&uap, sizeof(uap)); 264 uap.start = 0; 265 uap.num = 1; 266 lcall_addr = curproc->p_sysent->sv_psstrings - sz_lcall_tramp; 267 bzero(&desc, sizeof(desc)); 268 desc.sd_type = SDT_MEMERA; 269 desc.sd_dpl = SEL_UPL; 270 desc.sd_p = 1; 271 desc.sd_def32 = 1; 272 desc.sd_gran = 1; 273 desc.sd_lolimit = 0xffff; 274 desc.sd_hilimit = 0xf; 275 desc.sd_lobase = lcall_addr; 276 desc.sd_hibase = lcall_addr >> 24; 277 error = amd64_set_ldt(curthread, &uap, &desc); 278 if (error != 0) 279 return (error); 280 281 return (0); 282} 283#endif 284