1 2 /*--------------------------------------------------------------------*/ 3 /*--- Create/destroy signal delivery frames. ---*/ 4 /*--- sigframe-arm-linux.c ---*/ 5 /*--------------------------------------------------------------------*/ 6 7 /* 8 This file is part of Valgrind, a dynamic binary instrumentation 9 framework. 10 11 Copyright (C) 2000-2012 Nicholas Nethercote 12 njn (at) valgrind.org 13 Copyright (C) 2004-2012 Paul Mackerras 14 paulus (at) samba.org 15 Copyright (C) 2008-2012 Evan Geller 16 gaze (at) bea.ms 17 18 This program is free software; you can redistribute it and/or 19 modify it under the terms of the GNU General Public License as 20 published by the Free Software Foundation; either version 2 of the 21 License, or (at your option) any later version. 22 23 This program is distributed in the hope that it will be useful, but 24 WITHOUT ANY WARRANTY; without even the implied warranty of 25 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 26 General Public License for more details. 27 28 You should have received a copy of the GNU General Public License 29 along with this program; if not, write to the Free Software 30 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 31 02111-1307, USA. 32 33 The GNU General Public License is contained in the file COPYING. 34 */ 35 36 #if defined(VGP_arm_linux) 37 38 #include "pub_core_basics.h" 39 #include "pub_core_vki.h" 40 #include "pub_core_vkiscnums.h" 41 #include "pub_core_libcsetjmp.h" // to keep _threadstate.h happy 42 #include "pub_core_threadstate.h" 43 #include "pub_core_aspacemgr.h" 44 #include "pub_core_libcbase.h" 45 #include "pub_core_libcassert.h" 46 #include "pub_core_libcprint.h" 47 #include "pub_core_machine.h" 48 #include "pub_core_options.h" 49 #include "pub_core_sigframe.h" 50 #include "pub_core_signals.h" 51 #include "pub_core_tooliface.h" 52 #include "pub_core_trampoline.h" 53 #include "pub_core_transtab.h" // VG_(discard_translations) 54 55 56 /* This uses the hack of dumping the vex guest state along with both 57 shadows in the frame, and restoring it afterwards from there, 58 rather than pulling it out of the ucontext. That means that signal 59 handlers which modify the ucontext and then return, expecting their 60 modifications to take effect, will have those modifications 61 ignored. This could be fixed properly with an hour or so more 62 effort. */ 63 64 65 struct vg_sig_private { 66 UInt magicPI; 67 UInt sigNo_private; 68 VexGuestARMState vex; 69 VexGuestARMState vex_shadow1; 70 VexGuestARMState vex_shadow2; 71 }; 72 73 struct sigframe { 74 struct vki_ucontext uc; 75 unsigned long retcode[2]; 76 struct vg_sig_private vp; 77 }; 78 79 struct rt_sigframe { 80 vki_siginfo_t info; 81 struct sigframe sig; 82 }; 83 84 static Bool extend ( ThreadState *tst, Addr addr, SizeT size ) 85 { 86 ThreadId tid = tst->tid; 87 NSegment const* stackseg = NULL; 88 89 if (VG_(extend_stack)(addr, tst->client_stack_szB)) { 90 stackseg = VG_(am_find_nsegment)(addr); 91 if (0 && stackseg) 92 VG_(printf)("frame=%#lx seg=%#lx-%#lx\n", 93 addr, stackseg->start, stackseg->end); 94 } 95 96 if (stackseg == NULL || !stackseg->hasR || !stackseg->hasW) { 97 VG_(message)( 98 Vg_UserMsg, 99 "Can't extend stack to %#lx during signal delivery for thread %d:", 100 addr, tid); 101 if (stackseg == NULL) 102 VG_(message)(Vg_UserMsg, " no stack segment"); 103 else 104 VG_(message)(Vg_UserMsg, " too small or bad protection modes"); 105 106 /* set SIGSEGV to default handler */ 107 VG_(set_default_handler)(VKI_SIGSEGV); 108 VG_(synth_fault_mapping)(tid, addr); 109 110 /* The whole process should be about to die, since the default 111 action of SIGSEGV to kill the whole process. */ 112 return False; 113 } 114 115 /* For tracking memory events, indicate the entire frame has been 116 allocated. */ 117 VG_TRACK( new_mem_stack_signal, addr - VG_STACK_REDZONE_SZB, 118 size + VG_STACK_REDZONE_SZB, tid ); 119 120 return True; 121 } 122 123 static void synth_ucontext( ThreadId tid, const vki_siginfo_t *si, 124 UWord trapno, UWord err, const vki_sigset_t *set, 125 struct vki_ucontext *uc){ 126 127 ThreadState *tst = VG_(get_ThreadState)(tid); 128 struct vki_sigcontext *sc = &uc->uc_mcontext; 129 130 VG_(memset)(uc, 0, sizeof(*uc)); 131 132 uc->uc_flags = 0; 133 uc->uc_link = 0; 134 uc->uc_sigmask = *set; 135 uc->uc_stack = tst->altstack; 136 137 # define SC2(reg,REG) sc->arm_##reg = tst->arch.vex.guest_##REG 138 SC2(r0,R0); 139 SC2(r1,R1); 140 SC2(r2,R2); 141 SC2(r3,R3); 142 SC2(r4,R4); 143 SC2(r5,R5); 144 SC2(r6,R6); 145 SC2(r7,R7); 146 SC2(r8,R8); 147 SC2(r9,R9); 148 SC2(r10,R10); 149 SC2(fp,R11); 150 SC2(ip,R12); 151 SC2(sp,R13); 152 SC2(lr,R14); 153 SC2(pc,R15T); 154 # undef SC2 155 156 sc->trap_no = trapno; 157 sc->error_code = err; 158 sc->fault_address = (UInt)si->_sifields._sigfault._addr; 159 } 160 161 162 static void build_sigframe(ThreadState *tst, 163 struct sigframe *frame, 164 const vki_siginfo_t *siginfo, 165 const struct vki_ucontext *siguc, 166 void *handler, UInt flags, 167 const vki_sigset_t *mask, 168 void *restorer){ 169 170 UWord trapno; 171 UWord err; 172 Int sigNo = siginfo->si_signo; 173 struct vg_sig_private *priv = &frame->vp; 174 175 VG_TRACK( pre_mem_write, Vg_CoreSignal, tst->tid, "signal handler frame", 176 (Addr)frame, offsetof(struct sigframe, vp)); 177 178 if(siguc) { 179 trapno = siguc->uc_mcontext.trap_no; 180 err = siguc->uc_mcontext.error_code; 181 } else { 182 trapno = 0; 183 err = 0; 184 } 185 186 synth_ucontext(tst->tid, siginfo, trapno, err, mask, &frame->uc); 187 188 VG_TRACK( post_mem_write, Vg_CoreSignal, tst->tid, 189 (Addr)frame, offsetof(struct sigframe, vp)); 190 191 priv->magicPI = 0x31415927; 192 priv->sigNo_private = sigNo; 193 priv->vex = tst->arch.vex; 194 priv->vex_shadow1 = tst->arch.vex_shadow1; 195 priv->vex_shadow2 = tst->arch.vex_shadow2; 196 197 } 198 199 200 201 /* EXPORTED */ 202 void VG_(sigframe_create)( ThreadId tid, 203 Addr sp_top_of_frame, 204 const vki_siginfo_t *siginfo, 205 const struct vki_ucontext *siguc, 206 void *handler, 207 UInt flags, 208 const vki_sigset_t *mask, 209 void *restorer ) 210 { 211 // struct vg_sig_private *priv; 212 Addr sp = sp_top_of_frame; 213 ThreadState *tst; 214 Int sigNo = siginfo->si_signo; 215 // Addr faultaddr; 216 UInt size; 217 218 tst = VG_(get_ThreadState)(tid); 219 220 size = flags & VKI_SA_SIGINFO ? sizeof(struct rt_sigframe) : 221 sizeof(struct sigframe); 222 223 sp -= size; 224 sp = VG_ROUNDDN(sp, 16); 225 226 if(!extend(tst, sp, size)) 227 I_die_here; // XXX Incorrect behavior 228 229 230 if (flags & VKI_SA_SIGINFO){ 231 struct rt_sigframe *rsf = (struct rt_sigframe *)sp; 232 233 /* Track our writes to siginfo */ 234 VG_TRACK( pre_mem_write, Vg_CoreSignal, tst->tid, /* VVVVV */ 235 "signal handler siginfo", (Addr)rsf, 236 offsetof(struct rt_sigframe, sig)); 237 238 VG_(memcpy)(&rsf->info, siginfo, sizeof(vki_siginfo_t)); 239 240 if(sigNo == VKI_SIGILL && siginfo->si_code > 0) { 241 rsf->info._sifields._sigfault._addr = (Addr *) (tst)->arch.vex.guest_R12; /* IP */ 242 } 243 VG_TRACK( post_mem_write, Vg_CoreSignal, tst->tid, /* ^^^^^ */ 244 (Addr)rsf, offsetof(struct rt_sigframe, sig)); 245 246 build_sigframe(tst, &rsf->sig, siginfo, siguc, 247 handler, flags, mask, restorer); 248 tst->arch.vex.guest_R1 = (Addr)&rsf->info; 249 tst->arch.vex.guest_R2 = (Addr)&rsf->sig.uc; 250 } 251 else { 252 build_sigframe(tst, (struct sigframe *)sp, siginfo, siguc, 253 handler, flags, mask, restorer); 254 } 255 256 VG_(set_SP)(tid, sp); 257 VG_TRACK( post_reg_write, Vg_CoreSignal, tid, VG_O_STACK_PTR, 258 sizeof(Addr)); 259 tst->arch.vex.guest_R0 = sigNo; 260 261 if (flags & VKI_SA_RESTORER) 262 tst->arch.vex.guest_R14 = (Addr)restorer; 263 else 264 tst->arch.vex.guest_R14 265 = (flags & VKI_SA_SIGINFO) 266 ? (Addr)&VG_(arm_linux_SUBST_FOR_rt_sigreturn) 267 : (Addr)&VG_(arm_linux_SUBST_FOR_sigreturn); 268 269 tst->arch.vex.guest_R15T = (Addr) handler; /* R15 == PC */ 270 } 271 272 273 /*------------------------------------------------------------*/ 274 /*--- Destroying signal frames ---*/ 275 /*------------------------------------------------------------*/ 276 277 /* EXPORTED */ 278 void VG_(sigframe_destroy)( ThreadId tid, Bool isRT ) 279 { 280 ThreadState *tst; 281 struct vg_sig_private *priv; 282 Addr sp; 283 UInt frame_size; 284 struct vki_sigcontext *mc; 285 Int sigNo; 286 Bool has_siginfo = isRT; 287 288 vg_assert(VG_(is_valid_tid)(tid)); 289 tst = VG_(get_ThreadState)(tid); 290 sp = tst->arch.vex.guest_R13; 291 292 if (has_siginfo) { 293 struct rt_sigframe *frame = (struct rt_sigframe *)sp; 294 frame_size = sizeof(*frame); 295 mc = &frame->sig.uc.uc_mcontext; 296 priv = &frame->sig.vp; 297 vg_assert(priv->magicPI == 0x31415927); 298 tst->sig_mask = frame->sig.uc.uc_sigmask; 299 } else { 300 struct sigframe *frame = (struct sigframe *)sp; 301 frame_size = sizeof(*frame); 302 mc = &frame->uc.uc_mcontext; 303 priv = &frame->vp; 304 vg_assert(priv->magicPI == 0x31415927); 305 tst->sig_mask = frame->uc.uc_sigmask; 306 /*tst->sig_mask.sig[0] = frame->uc.uc_mcontext.oldmask; 307 tst->sig_mask.sig[1] = frame->uc.uc_mcontext._unused[3]; 308 VG_(printf)("Setting signmask to %08x%08x\n",tst->sig_mask[0],tst->sig_mask[1]); 309 */ 310 } 311 tst->tmp_sig_mask = tst->sig_mask; 312 313 sigNo = priv->sigNo_private; 314 315 //XXX: restore regs 316 # define REST(reg,REG) tst->arch.vex.guest_##REG = mc->arm_##reg; 317 REST(r0,R0); 318 REST(r1,R1); 319 REST(r2,R2); 320 REST(r3,R3); 321 REST(r4,R4); 322 REST(r5,R5); 323 REST(r6,R6); 324 REST(r7,R7); 325 REST(r8,R8); 326 REST(r9,R9); 327 REST(r10,R10); 328 REST(fp,R11); 329 REST(ip,R12); 330 REST(sp,R13); 331 REST(lr,R14); 332 REST(pc,R15T); 333 # undef REST 334 335 /* Uh, the next line makes all the REST() above pointless. */ 336 tst->arch.vex = priv->vex; 337 338 tst->arch.vex_shadow1 = priv->vex_shadow1; 339 tst->arch.vex_shadow2 = priv->vex_shadow2; 340 341 VG_TRACK( die_mem_stack_signal, sp - VG_STACK_REDZONE_SZB, 342 frame_size + VG_STACK_REDZONE_SZB ); 343 344 if (VG_(clo_trace_signals)) 345 VG_(message)(Vg_DebugMsg, 346 "vg_pop_signal_frame (thread %d): " 347 "isRT=%d valid magic; PC=%#x\n", 348 tid, has_siginfo, tst->arch.vex.guest_R15T); 349 350 /* tell the tools */ 351 VG_TRACK( post_deliver_signal, tid, sigNo ); 352 } 353 354 #endif // defined(VGP_arm_linux) 355 356 /*--------------------------------------------------------------------*/ 357 /*--- end sigframe-arm-linux.c ---*/ 358 /*--------------------------------------------------------------------*/ 359
