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) 2000-2017 Nicholas Nethercote 12 njn (at) valgrind.org 13 Copyright (C) 2004-2017 Paul Mackerras 14 paulus (at) samba.org 15 Copyright (C) 2008-2017 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_threadstate.h" 42 #include "pub_core_aspacemgr.h" 43 #include "pub_core_libcbase.h" 44 #include "pub_core_libcassert.h" 45 #include "pub_core_libcprint.h" 46 #include "pub_core_machine.h" 47 #include "pub_core_options.h" 48 #include "pub_core_sigframe.h" 49 #include "pub_core_signals.h" 50 #include "pub_core_tooliface.h" 51 #include "pub_core_trampoline.h" 52 #include "priv_sigframe.h" 53 54 55 /* This uses the hack of dumping the vex guest state along with both 56 shadows in the frame, and restoring it afterwards from there, 57 rather than pulling it out of the ucontext. That means that signal 58 handlers which modify the ucontext and then return, expecting their 59 modifications to take effect, will have those modifications 60 ignored. This could be fixed properly with an hour or so more 61 effort. */ 62 63 64 struct vg_sig_private { 65 UInt magicPI; 66 UInt sigNo_private; 67 VexGuestARMState vex; 68 VexGuestARMState vex_shadow1; 69 VexGuestARMState vex_shadow2; 70 }; 71 72 struct sigframe { 73 struct vki_ucontext uc; 74 unsigned long retcode[2]; 75 struct vg_sig_private vp; 76 }; 77 78 struct rt_sigframe { 79 vki_siginfo_t info; 80 struct sigframe sig; 81 }; 82 83 84 static void synth_ucontext( ThreadId tid, const vki_siginfo_t *si, 85 UWord trapno, UWord err, const vki_sigset_t *set, 86 struct vki_ucontext *uc){ 87 88 ThreadState *tst = VG_(get_ThreadState)(tid); 89 struct vki_sigcontext *sc = &uc->uc_mcontext; 90 91 VG_(memset)(uc, 0, sizeof(*uc)); 92 93 uc->uc_flags = 0; 94 uc->uc_link = 0; 95 uc->uc_sigmask = *set; 96 uc->uc_stack = tst->altstack; 97 98 # define SC2(reg,REG) sc->arm_##reg = tst->arch.vex.guest_##REG 99 SC2(r0,R0); 100 SC2(r1,R1); 101 SC2(r2,R2); 102 SC2(r3,R3); 103 SC2(r4,R4); 104 SC2(r5,R5); 105 SC2(r6,R6); 106 SC2(r7,R7); 107 SC2(r8,R8); 108 SC2(r9,R9); 109 SC2(r10,R10); 110 SC2(fp,R11); 111 SC2(ip,R12); 112 SC2(sp,R13); 113 SC2(lr,R14); 114 SC2(pc,R15T); 115 # undef SC2 116 117 sc->trap_no = trapno; 118 sc->error_code = err; 119 sc->fault_address = (UInt)si->_sifields._sigfault._addr; 120 } 121 122 123 static void build_sigframe(ThreadState *tst, 124 struct sigframe *frame, 125 const vki_siginfo_t *siginfo, 126 const struct vki_ucontext *siguc, 127 void *handler, UInt flags, 128 const vki_sigset_t *mask, 129 void *restorer){ 130 131 UWord trapno; 132 UWord err; 133 Int sigNo = siginfo->si_signo; 134 struct vg_sig_private *priv = &frame->vp; 135 136 VG_TRACK( pre_mem_write, Vg_CoreSignal, tst->tid, "signal handler frame", 137 (Addr)frame, offsetof(struct sigframe, vp)); 138 139 if(siguc) { 140 trapno = siguc->uc_mcontext.trap_no; 141 err = siguc->uc_mcontext.error_code; 142 } else { 143 trapno = 0; 144 err = 0; 145 } 146 147 synth_ucontext(tst->tid, siginfo, trapno, err, mask, &frame->uc); 148 149 VG_TRACK( post_mem_write, Vg_CoreSignal, tst->tid, 150 (Addr)frame, offsetof(struct sigframe, vp)); 151 152 priv->magicPI = 0x31415927; 153 priv->sigNo_private = sigNo; 154 priv->vex = tst->arch.vex; 155 priv->vex_shadow1 = tst->arch.vex_shadow1; 156 priv->vex_shadow2 = tst->arch.vex_shadow2; 157 158 } 159 160 161 162 /* EXPORTED */ 163 void VG_(sigframe_create)( ThreadId tid, 164 Bool on_altstack, 165 Addr sp_top_of_frame, 166 const vki_siginfo_t *siginfo, 167 const struct vki_ucontext *siguc, 168 void *handler, 169 UInt flags, 170 const vki_sigset_t *mask, 171 void *restorer ) 172 { 173 // struct vg_sig_private *priv; 174 Addr sp = sp_top_of_frame; 175 ThreadState *tst; 176 Int sigNo = siginfo->si_signo; 177 // Addr faultaddr; 178 UInt size; 179 180 tst = VG_(get_ThreadState)(tid); 181 182 size = flags & VKI_SA_SIGINFO ? sizeof(struct rt_sigframe) : 183 sizeof(struct sigframe); 184 185 sp -= size; 186 sp = VG_ROUNDDN(sp, 16); 187 188 if (! ML_(sf_maybe_extend_stack)(tst, sp, size, flags)) 189 I_die_here; // XXX Incorrect behavior 190 191 192 if (flags & VKI_SA_SIGINFO){ 193 struct rt_sigframe *rsf = (struct rt_sigframe *)sp; 194 195 /* Track our writes to siginfo */ 196 VG_TRACK( pre_mem_write, Vg_CoreSignal, tst->tid, /* VVVVV */ 197 "signal handler siginfo", (Addr)rsf, 198 offsetof(struct rt_sigframe, sig)); 199 200 VG_(memcpy)(&rsf->info, siginfo, sizeof(vki_siginfo_t)); 201 202 if(sigNo == VKI_SIGILL && siginfo->si_code > 0) { 203 rsf->info._sifields._sigfault._addr = (Addr *) (tst)->arch.vex.guest_R12; /* IP */ 204 } 205 VG_TRACK( post_mem_write, Vg_CoreSignal, tst->tid, /* ^^^^^ */ 206 (Addr)rsf, offsetof(struct rt_sigframe, sig)); 207 208 build_sigframe(tst, &rsf->sig, siginfo, siguc, 209 handler, flags, mask, restorer); 210 tst->arch.vex.guest_R1 = (Addr)&rsf->info; 211 tst->arch.vex.guest_R2 = (Addr)&rsf->sig.uc; 212 } 213 else { 214 build_sigframe(tst, (struct sigframe *)sp, siginfo, siguc, 215 handler, flags, mask, restorer); 216 } 217 218 VG_(set_SP)(tid, sp); 219 VG_TRACK( post_reg_write, Vg_CoreSignal, tid, VG_O_STACK_PTR, 220 sizeof(Addr)); 221 tst->arch.vex.guest_R0 = sigNo; 222 223 if (flags & VKI_SA_RESTORER) 224 tst->arch.vex.guest_R14 = (Addr)restorer; 225 else 226 tst->arch.vex.guest_R14 227 = (flags & VKI_SA_SIGINFO) 228 ? (Addr)&VG_(arm_linux_SUBST_FOR_rt_sigreturn) 229 : (Addr)&VG_(arm_linux_SUBST_FOR_sigreturn); 230 231 tst->arch.vex.guest_R15T = (Addr) handler; /* R15 == PC */ 232 233 if (VG_(clo_trace_signals)) 234 VG_(message)(Vg_DebugMsg, 235 "VG_(sigframe_create): continuing in handler with PC=%#lx\n", 236 (Addr)handler); 237 } 238 239 240 /*------------------------------------------------------------*/ 241 /*--- Destroying signal frames ---*/ 242 /*------------------------------------------------------------*/ 243 244 /* EXPORTED */ 245 void VG_(sigframe_destroy)( ThreadId tid, Bool isRT ) 246 { 247 ThreadState *tst; 248 struct vg_sig_private *priv; 249 Addr sp; 250 UInt frame_size; 251 Int sigNo; 252 Bool has_siginfo = isRT; 253 254 vg_assert(VG_(is_valid_tid)(tid)); 255 tst = VG_(get_ThreadState)(tid); 256 sp = tst->arch.vex.guest_R13; 257 258 if (has_siginfo) { 259 struct rt_sigframe *frame = (struct rt_sigframe *)sp; 260 frame_size = sizeof(*frame); 261 priv = &frame->sig.vp; 262 vg_assert(priv->magicPI == 0x31415927); 263 tst->sig_mask = frame->sig.uc.uc_sigmask; 264 } else { 265 struct sigframe *frame = (struct sigframe *)sp; 266 frame_size = sizeof(*frame); 267 priv = &frame->vp; 268 vg_assert(priv->magicPI == 0x31415927); 269 tst->sig_mask = frame->uc.uc_sigmask; 270 /*tst->sig_mask.sig[0] = frame->uc.uc_mcontext.oldmask; 271 tst->sig_mask.sig[1] = frame->uc.uc_mcontext._unused[3]; 272 VG_(printf)("Setting signmask to %08x%08x\n",tst->sig_mask[0],tst->sig_mask[1]); 273 */ 274 } 275 tst->tmp_sig_mask = tst->sig_mask; 276 277 sigNo = priv->sigNo_private; 278 279 //ZZ //XXX: restore regs 280 //ZZ # define REST(reg,REG) tst->arch.vex.guest_##REG = mc->arm_##reg; 281 //ZZ REST(r0,R0); 282 //ZZ REST(r1,R1); 283 //ZZ REST(r2,R2); 284 //ZZ REST(r3,R3); 285 //ZZ REST(r4,R4); 286 //ZZ REST(r5,R5); 287 //ZZ REST(r6,R6); 288 //ZZ REST(r7,R7); 289 //ZZ REST(r8,R8); 290 //ZZ REST(r9,R9); 291 //ZZ REST(r10,R10); 292 //ZZ REST(fp,R11); 293 //ZZ REST(ip,R12); 294 //ZZ REST(sp,R13); 295 //ZZ REST(lr,R14); 296 //ZZ REST(pc,R15T); 297 //ZZ # undef REST 298 299 /* Uh, the next line makes all the REST() above pointless. */ 300 tst->arch.vex = priv->vex; 301 302 tst->arch.vex_shadow1 = priv->vex_shadow1; 303 tst->arch.vex_shadow2 = priv->vex_shadow2; 304 305 VG_TRACK( die_mem_stack_signal, sp - VG_STACK_REDZONE_SZB, 306 frame_size + VG_STACK_REDZONE_SZB ); 307 308 if (VG_(clo_trace_signals)) 309 VG_(message)(Vg_DebugMsg, 310 "vg_pop_signal_frame (thread %u): " 311 "isRT=%d valid magic; PC=%#x\n", 312 tid, has_siginfo, tst->arch.vex.guest_R15T); 313 314 /* tell the tools */ 315 VG_TRACK( post_deliver_signal, tid, sigNo ); 316 } 317 318 #endif // defined(VGP_arm_linux) 319 320 /*--------------------------------------------------------------------*/ 321 /*--- end sigframe-arm-linux.c ---*/ 322 /*--------------------------------------------------------------------*/ 323
