| 1 | /* $NetBSD: linux_machdep.c,v 1.48 2014/02/19 20:50:56 dsl Exp $ */ |
| 2 | |
| 3 | /*- |
| 4 | * Copyright (c) 2005 Emmanuel Dreyfus, all rights reserved. |
| 5 | * |
| 6 | * Redistribution and use in source and binary forms, with or without |
| 7 | * modification, are permitted provided that the following conditions |
| 8 | * are met: |
| 9 | * 1. Redistributions of source code must retain the above copyright |
| 10 | * notice, this list of conditions and the following disclaimer. |
| 11 | * 2. Redistributions in binary form must reproduce the above copyright |
| 12 | * notice, this list of conditions and the following disclaimer in the |
| 13 | * documentation and/or other materials provided with the distribution. |
| 14 | * 3. All advertising materials mentioning features or use of this software |
| 15 | * must display the following acknowledgement: |
| 16 | * This product includes software developed by Emmanuel Dreyfus |
| 17 | * 4. The name of the author may not be used to endorse or promote |
| 18 | * products derived from this software without specific prior written |
| 19 | * permission. |
| 20 | * |
| 21 | * THIS SOFTWARE IS PROVIDED BY THE THE AUTHOR AND CONTRIBUTORS ``AS IS'' |
| 22 | * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, |
| 23 | * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
| 24 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS |
| 25 | * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| 26 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| 27 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| 28 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| 29 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| 30 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| 31 | * POSSIBILITY OF SUCH DAMAGE. |
| 32 | */ |
| 33 | |
| 34 | #include <sys/cdefs.h> |
| 35 | |
| 36 | __KERNEL_RCSID(0, "$NetBSD: linux_machdep.c,v 1.48 2014/02/19 20:50:56 dsl Exp $" ); |
| 37 | |
| 38 | #include <sys/param.h> |
| 39 | #include <sys/types.h> |
| 40 | #include <sys/systm.h> |
| 41 | #include <sys/signal.h> |
| 42 | #include <sys/exec.h> |
| 43 | #include <sys/proc.h> |
| 44 | #include <sys/ptrace.h> /* for process_read_fpregs() */ |
| 45 | #include <sys/ucontext.h> |
| 46 | #include <sys/conf.h> |
| 47 | |
| 48 | #include <machine/reg.h> |
| 49 | #include <machine/pcb.h> |
| 50 | #include <machine/mcontext.h> |
| 51 | #include <machine/specialreg.h> |
| 52 | #include <machine/vmparam.h> |
| 53 | #include <machine/cpufunc.h> |
| 54 | #include <x86/include/sysarch.h> |
| 55 | |
| 56 | /* |
| 57 | * To see whether wscons is configured (for virtual console ioctl calls). |
| 58 | */ |
| 59 | #if defined(_KERNEL_OPT) |
| 60 | #include "wsdisplay.h" |
| 61 | #endif |
| 62 | #if (NWSDISPLAY > 0) |
| 63 | #include <dev/wscons/wsconsio.h> |
| 64 | #include <dev/wscons/wsdisplay_usl_io.h> |
| 65 | #endif |
| 66 | |
| 67 | |
| 68 | #include <compat/linux/common/linux_signal.h> |
| 69 | #include <compat/linux/common/linux_errno.h> |
| 70 | #include <compat/linux/common/linux_exec.h> |
| 71 | #include <compat/linux/common/linux_ioctl.h> |
| 72 | #include <compat/linux/common/linux_prctl.h> |
| 73 | #include <compat/linux/common/linux_machdep.h> |
| 74 | #include <compat/linux/common/linux_ipc.h> |
| 75 | #include <compat/linux/common/linux_sem.h> |
| 76 | #include <compat/linux/linux_syscall.h> |
| 77 | #include <compat/linux/linux_syscallargs.h> |
| 78 | |
| 79 | static void linux_buildcontext(struct lwp *, void *, void *); |
| 80 | |
| 81 | void |
| 82 | linux_setregs(struct lwp *l, struct exec_package *epp, vaddr_t stack) |
| 83 | { |
| 84 | struct pcb *pcb = lwp_getpcb(l); |
| 85 | struct trapframe *tf; |
| 86 | |
| 87 | fpu_save_area_clear(l, __NetBSD_NPXCW__); |
| 88 | pcb->pcb_flags = 0; |
| 89 | |
| 90 | l->l_proc->p_flag &= ~PK_32; |
| 91 | |
| 92 | tf = l->l_md.md_regs; |
| 93 | tf->tf_rax = 0; |
| 94 | tf->tf_rbx = 0; |
| 95 | tf->tf_rcx = epp->ep_entry; |
| 96 | tf->tf_rdx = 0; |
| 97 | tf->tf_rsi = 0; |
| 98 | tf->tf_rdi = 0; |
| 99 | tf->tf_rbp = 0; |
| 100 | tf->tf_rsp = stack; |
| 101 | tf->tf_r8 = 0; |
| 102 | tf->tf_r9 = 0; |
| 103 | tf->tf_r10 = 0; |
| 104 | tf->tf_r11 = 0; |
| 105 | tf->tf_r12 = 0; |
| 106 | tf->tf_r13 = 0; |
| 107 | tf->tf_r14 = 0; |
| 108 | tf->tf_r15 = 0; |
| 109 | tf->tf_rip = epp->ep_entry; |
| 110 | tf->tf_rflags = PSL_USERSET; |
| 111 | tf->tf_cs = GSEL(GUCODE_SEL, SEL_UPL); |
| 112 | tf->tf_ss = GSEL(GUDATA_SEL, SEL_UPL); |
| 113 | tf->tf_ds = GSEL(GUDATA_SEL, SEL_UPL); |
| 114 | tf->tf_es = 0; |
| 115 | cpu_fsgs_zero(l); |
| 116 | |
| 117 | return; |
| 118 | } |
| 119 | |
| 120 | void |
| 121 | linux_sendsig(const ksiginfo_t *ksi, const sigset_t *mask) |
| 122 | { |
| 123 | struct lwp *l = curlwp; |
| 124 | struct proc *p = l->l_proc; |
| 125 | struct pcb *pcb = lwp_getpcb(l); |
| 126 | struct sigacts *ps = p->p_sigacts; |
| 127 | int onstack, error; |
| 128 | int sig = ksi->ksi_signo; |
| 129 | struct linux_rt_sigframe *sfp, sigframe; |
| 130 | struct linux__fpstate *fpsp; |
| 131 | struct fpreg fpregs; |
| 132 | struct trapframe *tf = l->l_md.md_regs; |
| 133 | sig_t catcher = SIGACTION(p, sig).sa_handler; |
| 134 | linux_sigset_t lmask; |
| 135 | char *sp; |
| 136 | |
| 137 | /* Do we need to jump onto the signal stack? */ |
| 138 | onstack = |
| 139 | (l->l_sigstk.ss_flags & (SS_DISABLE | SS_ONSTACK)) == 0 && |
| 140 | (SIGACTION(p, sig).sa_flags & SA_ONSTACK) != 0; |
| 141 | |
| 142 | /* Allocate space for the signal handler context. */ |
| 143 | if (onstack) |
| 144 | sp = ((char *)l->l_sigstk.ss_sp + |
| 145 | l->l_sigstk.ss_size); |
| 146 | else |
| 147 | sp = (char *)tf->tf_rsp - 128; |
| 148 | |
| 149 | /* Save FPU state */ |
| 150 | sp = (char *) (((long)sp - sizeof (*fpsp)) & ~0xfUL); |
| 151 | fpsp = (struct linux__fpstate *)sp; |
| 152 | |
| 153 | /* |
| 154 | * Populate the rt_sigframe |
| 155 | */ |
| 156 | sp = (char *) |
| 157 | ((((long)sp - sizeof(struct linux_rt_sigframe)) & ~0xfUL) - 8); |
| 158 | sfp = (struct linux_rt_sigframe *)sp; |
| 159 | |
| 160 | memset(&sigframe, 0, sizeof(sigframe)); |
| 161 | if (ps->sa_sigdesc[sig].sd_vers != 0) |
| 162 | sigframe.pretcode = |
| 163 | (char *)(u_long)ps->sa_sigdesc[sig].sd_tramp; |
| 164 | else |
| 165 | sigframe.pretcode = NULL; |
| 166 | |
| 167 | /* |
| 168 | * The user context |
| 169 | */ |
| 170 | sigframe.uc.luc_flags = 0; |
| 171 | sigframe.uc.luc_link = NULL; |
| 172 | |
| 173 | /* This is used regardless of SA_ONSTACK in Linux */ |
| 174 | sigframe.uc.luc_stack.ss_sp = l->l_sigstk.ss_sp; |
| 175 | sigframe.uc.luc_stack.ss_size = l->l_sigstk.ss_size; |
| 176 | sigframe.uc.luc_stack.ss_flags = 0; |
| 177 | if (l->l_sigstk.ss_flags & SS_ONSTACK) |
| 178 | sigframe.uc.luc_stack.ss_flags |= LINUX_SS_ONSTACK; |
| 179 | if (l->l_sigstk.ss_flags & SS_DISABLE) |
| 180 | sigframe.uc.luc_stack.ss_flags |= LINUX_SS_DISABLE; |
| 181 | |
| 182 | sigframe.uc.luc_mcontext.r8 = tf->tf_r8; |
| 183 | sigframe.uc.luc_mcontext.r9 = tf->tf_r9; |
| 184 | sigframe.uc.luc_mcontext.r10 = tf->tf_r10; |
| 185 | sigframe.uc.luc_mcontext.r11 = tf->tf_r11; |
| 186 | sigframe.uc.luc_mcontext.r12 = tf->tf_r12; |
| 187 | sigframe.uc.luc_mcontext.r13 = tf->tf_r13; |
| 188 | sigframe.uc.luc_mcontext.r14 = tf->tf_r14; |
| 189 | sigframe.uc.luc_mcontext.r15 = tf->tf_r15; |
| 190 | sigframe.uc.luc_mcontext.rdi = tf->tf_rdi; |
| 191 | sigframe.uc.luc_mcontext.rsi = tf->tf_rsi; |
| 192 | sigframe.uc.luc_mcontext.rbp = tf->tf_rbp; |
| 193 | sigframe.uc.luc_mcontext.rbx = tf->tf_rbx; |
| 194 | sigframe.uc.luc_mcontext.rdx = tf->tf_rdx; |
| 195 | sigframe.uc.luc_mcontext.rax = tf->tf_rax; |
| 196 | sigframe.uc.luc_mcontext.rcx = tf->tf_rcx; |
| 197 | sigframe.uc.luc_mcontext.rsp = tf->tf_rsp; |
| 198 | sigframe.uc.luc_mcontext.rip = tf->tf_rip; |
| 199 | sigframe.uc.luc_mcontext.eflags = tf->tf_rflags; |
| 200 | sigframe.uc.luc_mcontext.cs = tf->tf_cs; |
| 201 | sigframe.uc.luc_mcontext.gs = tf->tf_gs; |
| 202 | sigframe.uc.luc_mcontext.fs = tf->tf_fs; |
| 203 | sigframe.uc.luc_mcontext.err = tf->tf_err; |
| 204 | sigframe.uc.luc_mcontext.trapno = tf->tf_trapno; |
| 205 | native_to_linux_sigset(&lmask, mask); |
| 206 | sigframe.uc.luc_mcontext.oldmask = lmask.sig[0]; |
| 207 | sigframe.uc.luc_mcontext.cr2 = (long)pcb->pcb_onfault; |
| 208 | sigframe.uc.luc_mcontext.fpstate = fpsp; |
| 209 | native_to_linux_sigset(&sigframe.uc.luc_sigmask, mask); |
| 210 | native_to_linux_siginfo(&sigframe.info, &ksi->ksi_info); |
| 211 | sendsig_reset(l, sig); |
| 212 | mutex_exit(p->p_lock); |
| 213 | error = 0; |
| 214 | |
| 215 | /* |
| 216 | * Save FPU state, if any |
| 217 | */ |
| 218 | if (fpsp != NULL) { |
| 219 | size_t fp_size = sizeof fpregs; |
| 220 | /* The netbsd and linux structures both match the fxsave data */ |
| 221 | (void)process_read_fpregs(l, &fpregs, &fp_size); |
| 222 | error = copyout(&fpregs, fpsp, sizeof(*fpsp)); |
| 223 | } |
| 224 | |
| 225 | if (error == 0) |
| 226 | error = copyout(&sigframe, sp, sizeof(sigframe)); |
| 227 | |
| 228 | mutex_enter(p->p_lock); |
| 229 | |
| 230 | if (error != 0) { |
| 231 | sigexit(l, SIGILL); |
| 232 | return; |
| 233 | } |
| 234 | |
| 235 | linux_buildcontext(l, catcher, sp); |
| 236 | tf->tf_rdi = sigframe.info.lsi_signo; |
| 237 | tf->tf_rax = 0; |
| 238 | tf->tf_rsi = (long)&sfp->info; |
| 239 | tf->tf_rdx = (long)&sfp->uc; |
| 240 | |
| 241 | /* |
| 242 | * Remember we use signal stack |
| 243 | */ |
| 244 | if (onstack) |
| 245 | l->l_sigstk.ss_flags |= SS_ONSTACK; |
| 246 | return; |
| 247 | } |
| 248 | |
| 249 | int |
| 250 | linux_sys_modify_ldt(struct lwp *l, const struct linux_sys_modify_ldt_args *v, register_t *retval) |
| 251 | { |
| 252 | printf("linux_sys_modify_ldt\n" ); |
| 253 | return 0; |
| 254 | } |
| 255 | |
| 256 | int |
| 257 | linux_sys_iopl(struct lwp *l, const struct linux_sys_iopl_args *v, register_t *retval) |
| 258 | { |
| 259 | return 0; |
| 260 | } |
| 261 | |
| 262 | int |
| 263 | linux_sys_ioperm(struct lwp *l, const struct linux_sys_ioperm_args *v, register_t *retval) |
| 264 | { |
| 265 | return 0; |
| 266 | } |
| 267 | |
| 268 | dev_t |
| 269 | linux_fakedev(dev_t dev, int raw) |
| 270 | { |
| 271 | |
| 272 | extern const struct cdevsw ptc_cdevsw, pts_cdevsw; |
| 273 | const struct cdevsw *cd = cdevsw_lookup(dev); |
| 274 | |
| 275 | if (raw) { |
| 276 | #if (NWSDISPLAY > 0) |
| 277 | extern const struct cdevsw wsdisplay_cdevsw; |
| 278 | if (cd == &wsdisplay_cdevsw) |
| 279 | return makedev(LINUX_CONS_MAJOR, (minor(dev) + 1)); |
| 280 | #endif |
| 281 | } |
| 282 | |
| 283 | if (cd == &ptc_cdevsw) |
| 284 | return makedev(LINUX_PTC_MAJOR, minor(dev)); |
| 285 | if (cd == &pts_cdevsw) |
| 286 | return makedev(LINUX_PTS_MAJOR, minor(dev)); |
| 287 | |
| 288 | return ((minor(dev) & 0xff) | ((major(dev) & 0xfff) << 8) |
| 289 | | (((unsigned long long int) (minor(dev) & ~0xff)) << 12) |
| 290 | | (((unsigned long long int) (major(dev) & ~0xfff)) << 32)); |
| 291 | } |
| 292 | |
| 293 | int |
| 294 | linux_machdepioctl(struct lwp *l, const struct linux_sys_ioctl_args *v, register_t *retval) |
| 295 | { |
| 296 | return 0; |
| 297 | } |
| 298 | |
| 299 | int |
| 300 | linux_sys_rt_sigreturn(struct lwp *l, const void *v, register_t *retval) |
| 301 | { |
| 302 | struct linux_ucontext *luctx; |
| 303 | struct trapframe *tf = l->l_md.md_regs; |
| 304 | struct linux_sigcontext *lsigctx; |
| 305 | struct linux_rt_sigframe frame, *fp; |
| 306 | ucontext_t uctx; |
| 307 | mcontext_t *mctx; |
| 308 | struct fxsave *fxarea; |
| 309 | int error; |
| 310 | |
| 311 | fp = (struct linux_rt_sigframe *)(tf->tf_rsp - 8); |
| 312 | if ((error = copyin(fp, &frame, sizeof(frame))) != 0) { |
| 313 | mutex_enter(l->l_proc->p_lock); |
| 314 | sigexit(l, SIGILL); |
| 315 | return error; |
| 316 | } |
| 317 | luctx = &frame.uc; |
| 318 | lsigctx = &luctx->luc_mcontext; |
| 319 | |
| 320 | memset(&uctx, 0, sizeof(uctx)); |
| 321 | mctx = (mcontext_t *)&uctx.uc_mcontext; |
| 322 | fxarea = (struct fxsave *)&mctx->__fpregs; |
| 323 | |
| 324 | /* |
| 325 | * Set the flags. Linux always have CPU, stack and signal state, |
| 326 | * FPU is optional. uc_flags is not used to tell what we have. |
| 327 | */ |
| 328 | uctx.uc_flags = (_UC_SIGMASK|_UC_CPU|_UC_STACK|_UC_CLRSTACK); |
| 329 | if (lsigctx->fpstate != NULL) |
| 330 | uctx.uc_flags |= _UC_FPU; |
| 331 | uctx.uc_link = NULL; |
| 332 | |
| 333 | /* |
| 334 | * Signal set |
| 335 | */ |
| 336 | linux_to_native_sigset(&uctx.uc_sigmask, &luctx->luc_sigmask); |
| 337 | |
| 338 | /* |
| 339 | * CPU state |
| 340 | */ |
| 341 | mctx->__gregs[_REG_R8] = lsigctx->r8; |
| 342 | mctx->__gregs[_REG_R9] = lsigctx->r9; |
| 343 | mctx->__gregs[_REG_R10] = lsigctx->r10; |
| 344 | mctx->__gregs[_REG_R11] = lsigctx->r11; |
| 345 | mctx->__gregs[_REG_R12] = lsigctx->r12; |
| 346 | mctx->__gregs[_REG_R13] = lsigctx->r13; |
| 347 | mctx->__gregs[_REG_R14] = lsigctx->r14; |
| 348 | mctx->__gregs[_REG_R15] = lsigctx->r15; |
| 349 | mctx->__gregs[_REG_RDI] = lsigctx->rdi; |
| 350 | mctx->__gregs[_REG_RSI] = lsigctx->rsi; |
| 351 | mctx->__gregs[_REG_RBP] = lsigctx->rbp; |
| 352 | mctx->__gregs[_REG_RBX] = lsigctx->rbx; |
| 353 | mctx->__gregs[_REG_RAX] = lsigctx->rax; |
| 354 | mctx->__gregs[_REG_RDX] = lsigctx->rdx; |
| 355 | mctx->__gregs[_REG_RCX] = lsigctx->rcx; |
| 356 | mctx->__gregs[_REG_RIP] = lsigctx->rip; |
| 357 | mctx->__gregs[_REG_RFLAGS] = lsigctx->eflags; |
| 358 | mctx->__gregs[_REG_CS] = lsigctx->cs; |
| 359 | mctx->__gregs[_REG_GS] = lsigctx->gs; |
| 360 | mctx->__gregs[_REG_FS] = lsigctx->fs; |
| 361 | mctx->__gregs[_REG_ERR] = lsigctx->err; |
| 362 | mctx->__gregs[_REG_TRAPNO] = lsigctx->trapno; |
| 363 | mctx->__gregs[_REG_ES] = tf->tf_es; |
| 364 | mctx->__gregs[_REG_DS] = tf->tf_ds; |
| 365 | mctx->__gregs[_REG_RSP] = lsigctx->rsp; /* XXX */ |
| 366 | mctx->__gregs[_REG_SS] = tf->tf_ss; |
| 367 | |
| 368 | /* |
| 369 | * FPU state |
| 370 | */ |
| 371 | if (lsigctx->fpstate != NULL) { |
| 372 | /* Both structures match the fxstate data */ |
| 373 | error = copyin(lsigctx->fpstate, fxarea, sizeof(*fxarea)); |
| 374 | if (error != 0) { |
| 375 | mutex_enter(l->l_proc->p_lock); |
| 376 | sigexit(l, SIGILL); |
| 377 | return error; |
| 378 | } |
| 379 | } |
| 380 | |
| 381 | /* |
| 382 | * And the stack |
| 383 | */ |
| 384 | uctx.uc_stack.ss_flags = 0; |
| 385 | if (luctx->luc_stack.ss_flags & LINUX_SS_ONSTACK) |
| 386 | uctx.uc_stack.ss_flags |= SS_ONSTACK; |
| 387 | |
| 388 | if (luctx->luc_stack.ss_flags & LINUX_SS_DISABLE) |
| 389 | uctx.uc_stack.ss_flags |= SS_DISABLE; |
| 390 | |
| 391 | uctx.uc_stack.ss_sp = luctx->luc_stack.ss_sp; |
| 392 | uctx.uc_stack.ss_size = luctx->luc_stack.ss_size; |
| 393 | |
| 394 | /* |
| 395 | * And let setucontext deal with that. |
| 396 | */ |
| 397 | mutex_enter(l->l_proc->p_lock); |
| 398 | error = setucontext(l, &uctx); |
| 399 | mutex_exit(l->l_proc->p_lock); |
| 400 | if (error) |
| 401 | return error; |
| 402 | |
| 403 | return EJUSTRETURN; |
| 404 | } |
| 405 | |
| 406 | int |
| 407 | linux_sys_arch_prctl(struct lwp *l, |
| 408 | const struct linux_sys_arch_prctl_args *uap, register_t *retval) |
| 409 | { |
| 410 | /* { |
| 411 | syscallarg(int) code; |
| 412 | syscallarg(unsigned long) addr; |
| 413 | } */ |
| 414 | void *addr = (void *)SCARG(uap, addr); |
| 415 | |
| 416 | switch(SCARG(uap, code)) { |
| 417 | case LINUX_ARCH_SET_GS: |
| 418 | return x86_set_sdbase(addr, 'g', l, true); |
| 419 | |
| 420 | case LINUX_ARCH_GET_GS: |
| 421 | return x86_get_sdbase(addr, 'g'); |
| 422 | |
| 423 | case LINUX_ARCH_SET_FS: |
| 424 | return x86_set_sdbase(addr, 'f', l, true); |
| 425 | |
| 426 | case LINUX_ARCH_GET_FS: |
| 427 | return x86_get_sdbase(addr, 'f'); |
| 428 | |
| 429 | default: |
| 430 | #ifdef DEBUG_LINUX |
| 431 | printf("linux_sys_arch_prctl: unexpected code %d\n" , |
| 432 | SCARG(uap, code)); |
| 433 | #endif |
| 434 | return EINVAL; |
| 435 | } |
| 436 | /* NOTREACHED */ |
| 437 | } |
| 438 | |
| 439 | const int linux_vsyscall_to_syscall[] = { |
| 440 | LINUX_SYS_gettimeofday, |
| 441 | LINUX_SYS_time, |
| 442 | LINUX_SYS_nosys, /* nosys */ |
| 443 | LINUX_SYS_nosys, /* nosys */ |
| 444 | }; |
| 445 | |
| 446 | int |
| 447 | linux_usertrap(struct lwp *l, vaddr_t trapaddr, void *arg) |
| 448 | { |
| 449 | struct trapframe *tf = arg; |
| 450 | uint64_t retaddr; |
| 451 | int vsyscallnr; |
| 452 | |
| 453 | /* |
| 454 | * Check for a vsyscall. %rip must be the fault address, |
| 455 | * and the address must be in the Linux vsyscall area. |
| 456 | * Also, vsyscalls are only done at 1024-byte boundaries. |
| 457 | */ |
| 458 | |
| 459 | if (__predict_true(trapaddr < LINUX_VSYSCALL_START)) |
| 460 | return 0; |
| 461 | |
| 462 | if (trapaddr != tf->tf_rip) |
| 463 | return 0; |
| 464 | |
| 465 | if ((tf->tf_rip & (LINUX_VSYSCALL_SIZE - 1)) != 0) |
| 466 | return 0; |
| 467 | |
| 468 | vsyscallnr = (tf->tf_rip - LINUX_VSYSCALL_START) / LINUX_VSYSCALL_SIZE; |
| 469 | |
| 470 | if (vsyscallnr > LINUX_VSYSCALL_MAXNR) |
| 471 | return 0; |
| 472 | |
| 473 | /* |
| 474 | * Get the return address from the top of the stack, |
| 475 | * and fix up the return address. |
| 476 | * This assumes the faulting instruction was callq *reg, |
| 477 | * which is the only way that vsyscalls are ever entered. |
| 478 | */ |
| 479 | if (copyin((void *)tf->tf_rsp, &retaddr, sizeof retaddr) != 0) |
| 480 | return 0; |
| 481 | tf->tf_rip = retaddr; |
| 482 | tf->tf_rax = linux_vsyscall_to_syscall[vsyscallnr]; |
| 483 | tf->tf_rsp += 8; /* "pop" the return address */ |
| 484 | |
| 485 | #if 0 |
| 486 | printf("usertrap: rip %p rsp %p retaddr %p vsys %d sys %d\n" , |
| 487 | (void *)tf->tf_rip, (void *)tf->tf_rsp, (void *)retaddr, |
| 488 | vsyscallnr, (int)tf->tf_rax); |
| 489 | #endif |
| 490 | |
| 491 | (*l->l_proc->p_md.md_syscall)(tf); |
| 492 | |
| 493 | return 1; |
| 494 | } |
| 495 | |
| 496 | static void |
| 497 | linux_buildcontext(struct lwp *l, void *catcher, void *f) |
| 498 | { |
| 499 | struct trapframe *tf = l->l_md.md_regs; |
| 500 | |
| 501 | tf->tf_ds = GSEL(GUDATA_SEL, SEL_UPL); |
| 502 | tf->tf_rip = (u_int64_t)catcher; |
| 503 | tf->tf_cs = GSEL(GUCODE_SEL, SEL_UPL); |
| 504 | tf->tf_rflags &= ~PSL_CLEARSIG; |
| 505 | tf->tf_rsp = (u_int64_t)f; |
| 506 | tf->tf_ss = GSEL(GUDATA_SEL, SEL_UPL); |
| 507 | } |
| 508 | |