dispatch-x86-linux.S revision ed07e00d438c74b7a23c01bfffde77e3968305e4
1 2/*--------------------------------------------------------------------*/ 3/*--- The core dispatch loop, for jumping to a code address. ---*/ 4/*--- dispatch-x86-linux.S ---*/ 5/*--------------------------------------------------------------------*/ 6 7/* 8 This file is part of Valgrind, a dynamic binary instrumentation 9 framework. 10 11 Copyright (C) 2000-2010 Julian Seward 12 jseward@acm.org 13 14 This program is free software; you can redistribute it and/or 15 modify it under the terms of the GNU General Public License as 16 published by the Free Software Foundation; either version 2 of the 17 License, or (at your option) any later version. 18 19 This program is distributed in the hope that it will be useful, but 20 WITHOUT ANY WARRANTY; without even the implied warranty of 21 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 22 General Public License for more details. 23 24 You should have received a copy of the GNU General Public License 25 along with this program; if not, write to the Free Software 26 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 27 02111-1307, USA. 28 29 The GNU General Public License is contained in the file COPYING. 30*/ 31 32#if defined(VGP_x86_linux) 33 34#include "pub_core_basics_asm.h" 35#include "pub_core_dispatch_asm.h" 36#include "pub_core_transtab_asm.h" 37#include "libvex_guest_offsets.h" /* for OFFSET_x86_EIP */ 38 39 40/*------------------------------------------------------------*/ 41/*--- ---*/ 42/*--- The dispatch loop. VG_(run_innerloop) is used to ---*/ 43/*--- run all translations except no-redir ones. ---*/ 44/*--- ---*/ 45/*------------------------------------------------------------*/ 46 47/*----------------------------------------------------*/ 48/*--- Preamble (set everything up) ---*/ 49/*----------------------------------------------------*/ 50 51/* signature: 52UWord VG_(run_innerloop) ( void* guest_state, UWord do_profiling ); 53*/ 54.text 55.globl VG_(run_innerloop) 56.type VG_(run_innerloop), @function 57VG_(run_innerloop): 58 /* 4(%esp) holds guest_state */ 59 /* 8(%esp) holds do_profiling */ 60 61 /* ----- entry point to VG_(run_innerloop) ----- */ 62 pushl %ebx 63 pushl %ecx 64 pushl %edx 65 pushl %esi 66 pushl %edi 67 pushl %ebp 68 69 /* 28(%esp) holds guest_state */ 70 /* 32(%esp) holds do_profiling */ 71 72 /* Set up the guest state pointer */ 73 movl 28(%esp), %ebp 74 75 /* fetch %EIP into %eax */ 76 movl OFFSET_x86_EIP(%ebp), %eax 77 78 /* set host FPU control word to the default mode expected 79 by VEX-generated code. See comments in libvex.h for 80 more info. */ 81 finit 82 pushl $0x027F 83 fldcw (%esp) 84 addl $4, %esp 85 86 /* set host SSE control word to the default mode expected 87 by VEX-generated code. */ 88 cmpl $0, VG_(machine_x86_have_mxcsr) 89 jz L1 90 pushl $0x1F80 91 ldmxcsr (%esp) 92 addl $4, %esp 93L1: 94 /* set dir flag to known value */ 95 cld 96 97 /* fall into main loop (the right one) */ 98 cmpl $0, 32(%esp) /* do_profiling */ 99 je VG_(run_innerloop__dispatch_unprofiled) 100 jmp VG_(run_innerloop__dispatch_profiled) 101 /*NOTREACHED*/ 102 103/*----------------------------------------------------*/ 104/*--- NO-PROFILING (standard) dispatcher ---*/ 105/*----------------------------------------------------*/ 106 107.align 16 108.global VG_(run_innerloop__dispatch_unprofiled) 109VG_(run_innerloop__dispatch_unprofiled): 110 /* AT ENTRY: %eax is next guest addr, %ebp is possibly 111 modified guest state ptr */ 112 113 /* Has the guest state pointer been messed with? If yes, exit. */ 114 cmpl 28(%esp), %ebp 115 jnz gsp_changed 116 117 /* save the jump address in the guest state */ 118 movl %eax, OFFSET_x86_EIP(%ebp) 119 120 /* Are we out of timeslice? If yes, defer to scheduler. */ 121 subl $1, VG_(dispatch_ctr) 122 jz counter_is_zero 123 124 /* try a fast lookup in the translation cache */ 125 movl %eax, %ebx /* next guest addr */ 126 andl $ VG_TT_FAST_MASK, %ebx /* entry# */ 127 movl 0+VG_(tt_fast)(,%ebx,8), %esi /* .guest */ 128 movl 4+VG_(tt_fast)(,%ebx,8), %edi /* .host */ 129 cmpl %eax, %esi 130 jnz fast_lookup_failed 131 132 /* Found a match. Jump to .host. */ 133 jmp *%edi 134 ud2 /* persuade insn decoders not to speculate past here */ 135 /* generated code should run, then jump back to 136 VG_(run_innerloop__dispatch_unprofiled). */ 137 /*NOTREACHED*/ 138 139/*----------------------------------------------------*/ 140/*--- PROFILING dispatcher (can be much slower) ---*/ 141/*----------------------------------------------------*/ 142 143.align 16 144.global VG_(run_innerloop__dispatch_profiled) 145VG_(run_innerloop__dispatch_profiled): 146 /* AT ENTRY: %eax is next guest addr, %ebp is possibly 147 modified guest state ptr */ 148 149 /* Has the guest state pointer been messed with? If yes, exit. */ 150 cmpl 28(%esp), %ebp 151 jnz gsp_changed 152 153 /* save the jump address in the guest state */ 154 movl %eax, OFFSET_x86_EIP(%ebp) 155 156 /* Are we out of timeslice? If yes, defer to scheduler. */ 157 subl $1, VG_(dispatch_ctr) 158 jz counter_is_zero 159 160 /* try a fast lookup in the translation cache */ 161 movl %eax, %ebx /* next guest addr */ 162 andl $ VG_TT_FAST_MASK, %ebx /* entry# */ 163 movl 0+VG_(tt_fast)(,%ebx,8), %esi /* .guest */ 164 movl 4+VG_(tt_fast)(,%ebx,8), %edi /* .host */ 165 cmpl %eax, %esi 166 jnz fast_lookup_failed 167 168 /* increment bb profile counter */ 169 /* note: innocuous as this sounds, it causes a huge amount more 170 stress on D1 and significantly slows everything down. */ 171 movl VG_(tt_fastN)(,%ebx,4), %edx 172 /* Use "addl $1", not "incl", to avoid partial-flags stall on P4 */ 173 addl $1, (%edx) 174 175 /* Found a match. Jump to .host. */ 176 jmp *%edi 177 ud2 /* persuade insn decoders not to speculate past here */ 178 /* generated code should run, then jump back to 179 VG_(run_innerloop__dispatch_profiled). */ 180 /*NOTREACHED*/ 181 182/*----------------------------------------------------*/ 183/*--- exit points ---*/ 184/*----------------------------------------------------*/ 185 186gsp_changed: 187 /* Someone messed with the gsp. Have to 188 defer to scheduler to resolve this. dispatch ctr 189 is not yet decremented, so no need to increment. */ 190 /* %EIP is NOT up to date here. First, need to write 191 %eax back to %EIP, but without trashing %ebp since 192 that holds the value we want to return to the scheduler. 193 Hence use %esi transiently for the guest state pointer. */ 194 movl 28(%esp), %esi 195 movl %eax, OFFSET_x86_EIP(%esi) 196 movl %ebp, %eax 197 jmp run_innerloop_exit 198 /*NOTREACHED*/ 199 200counter_is_zero: 201 /* %EIP is up to date here */ 202 /* back out decrement of the dispatch counter */ 203 addl $1, VG_(dispatch_ctr) 204 movl $ VG_TRC_INNER_COUNTERZERO, %eax 205 jmp run_innerloop_exit 206 /*NOTREACHED*/ 207 208fast_lookup_failed: 209 /* %EIP is up to date here */ 210 /* back out decrement of the dispatch counter */ 211 addl $1, VG_(dispatch_ctr) 212 movl $ VG_TRC_INNER_FASTMISS, %eax 213 jmp run_innerloop_exit 214 /*NOTREACHED*/ 215 216 217 218/* All exits from the dispatcher go through here. %eax holds 219 the return value. 220*/ 221run_innerloop_exit: 222 /* We're leaving. Check that nobody messed with 223 %mxcsr or %fpucw. We can't mess with %eax here as it 224 holds the tentative return value, but any other is OK. */ 225#if !defined(ENABLE_INNER) 226 /* This check fails for self-hosting, so skip in that case */ 227 pushl $0 228 fstcw (%esp) 229 cmpl $0x027F, (%esp) 230 popl %esi /* get rid of the word without trashing %eflags */ 231 jnz invariant_violation 232#endif 233 cmpl $0, VG_(machine_x86_have_mxcsr) 234 jz L2 235 pushl $0 236 stmxcsr (%esp) 237 andl $0xFFFFFFC0, (%esp) /* mask out status flags */ 238 cmpl $0x1F80, (%esp) 239 popl %esi 240 jnz invariant_violation 241L2: /* otherwise we're OK */ 242 jmp run_innerloop_exit_REALLY 243 244invariant_violation: 245 movl $ VG_TRC_INVARIANT_FAILED, %eax 246 jmp run_innerloop_exit_REALLY 247 248run_innerloop_exit_REALLY: 249 popl %ebp 250 popl %edi 251 popl %esi 252 popl %edx 253 popl %ecx 254 popl %ebx 255 ret 256.size VG_(run_innerloop), .-VG_(run_innerloop) 257 258 259/*------------------------------------------------------------*/ 260/*--- ---*/ 261/*--- A special dispatcher, for running no-redir ---*/ 262/*--- translations. Just runs the given translation once. ---*/ 263/*--- ---*/ 264/*------------------------------------------------------------*/ 265 266/* signature: 267void VG_(run_a_noredir_translation) ( UWord* argblock ); 268*/ 269 270/* Run a no-redir translation. argblock points to 4 UWords, 2 to carry args 271 and 2 to carry results: 272 0: input: ptr to translation 273 1: input: ptr to guest state 274 2: output: next guest PC 275 3: output: guest state pointer afterwards (== thread return code) 276*/ 277.align 16 278.global VG_(run_a_noredir_translation) 279.type VG_(run_a_noredir_translation), @function 280VG_(run_a_noredir_translation): 281 /* Save callee-saves regs */ 282 pushl %esi 283 pushl %edi 284 pushl %ebp 285 pushl %ebx 286 287 movl 20(%esp), %edi /* %edi = argblock */ 288 movl 4(%edi), %ebp /* argblock[1] */ 289 jmp *0(%edi) /* argblock[0] */ 290 /*NOTREACHED*/ 291 ud2 292 /* If the translation has been correctly constructed, we 293 should resume at the the following label. */ 294.global VG_(run_a_noredir_translation__return_point) 295VG_(run_a_noredir_translation__return_point): 296 movl 20(%esp), %edi 297 movl %eax, 8(%edi) /* argblock[2] */ 298 movl %ebp, 12(%edi) /* argblock[3] */ 299 300 popl %ebx 301 popl %ebp 302 popl %edi 303 popl %esi 304 ret 305.size VG_(run_a_noredir_translation), .-VG_(run_a_noredir_translation) 306 307 308/* Let the linker know we don't need an executable stack */ 309.section .note.GNU-stack,"",@progbits 310 311#endif // defined(VGP_x86_linux) 312 313/*--------------------------------------------------------------------*/ 314/*--- end ---*/ 315/*--------------------------------------------------------------------*/ 316