| |
| ##--------------------------------------------------------------------## |
| ##--- The core dispatch loop, for jumping to a code address. ---## |
| ##--- amd64/dispatch.S ---## |
| ##--------------------------------------------------------------------## |
| |
| /* |
| This file is part of Valgrind, a dynamic binary instrumentation |
| framework. |
| |
| Copyright (C) 2000-2005 Julian Seward |
| jseward@acm.org |
| |
| This program is free software; you can redistribute it and/or |
| modify it under the terms of the GNU General Public License as |
| published by the Free Software Foundation; either version 2 of the |
| License, or (at your option) any later version. |
| |
| This program is distributed in the hope that it will be useful, but |
| WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with this program; if not, write to the Free Software |
| Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA |
| 02111-1307, USA. |
| |
| The GNU General Public License is contained in the file COPYING. |
| */ |
| |
| #include "pub_basics_asm.h" |
| #include "pub_core_dispatch_asm.h" |
| #include "pub_core_transtab_asm.h" |
| #include "libvex_guest_offsets.h" /* for OFFSET_amd64_RIP */ |
| |
| |
| /*------------------------------------------------------------*/ |
| /*--- The dispatch loop. ---*/ |
| /*------------------------------------------------------------*/ |
| |
| /* signature: UWord VG_(run_innerloop) ( void* guest_state ) */ |
| |
| .globl VG_(run_innerloop) |
| VG_(run_innerloop): |
| /* %rdi holds guest_state */ |
| |
| /* ----- entry point to VG_(run_innerloop) ----- */ |
| pushq %rbx |
| pushq %rcx |
| pushq %rdx |
| pushq %rsi |
| pushq %rbp |
| pushq %r8 |
| pushq %r9 |
| pushq %r10 |
| pushq %r11 |
| pushq %r12 |
| pushq %r13 |
| pushq %r14 |
| pushq %r15 |
| pushq %rdi |
| |
| movq VG_(dispatch_ctr)@GOTPCREL(%rip), %rsi |
| pushq (%rsi) |
| |
| /* 8(%rsp) holds cached copy of guest_state */ |
| /* 0(%rsp) holds cached copy of VG_(dispatch_ctr) */ |
| |
| /* Set up the guest state pointer */ |
| movq %rdi, %rbp |
| |
| /* fetch %RIP into %rax */ |
| movq OFFSET_amd64_RIP(%rbp), %rax |
| |
| /* set host FPU control word to the default mode expected |
| by VEX-generated code. See comments in libvex.h for |
| more info. */ |
| finit |
| pushq $0x027F |
| fldcw (%rsp) |
| addq $8, %rsp |
| |
| /* set host SSE control word to the default mode expected |
| by VEX-generated code. */ |
| pushq $0x1F80 |
| ldmxcsr (%rsp) |
| addq $8, %rsp |
| |
| /* set dir flag to known value */ |
| cld |
| |
| /* fall into main loop */ |
| |
| /* Here, %rax is the only live (real) register. The entire |
| simulated state is saved in the ThreadState. */ |
| |
| dispatch_boring: |
| /* save the jump address in the guest state */ |
| movq %rax, OFFSET_amd64_RIP(%rbp) |
| |
| /* Are we out of timeslice? If yes, defer to scheduler. */ |
| subl $1, 0(%rsp) |
| jz counter_is_zero |
| |
| /* try a fast lookup in the translation cache */ |
| movq %rax, %rbx |
| andq $VG_TT_FAST_MASK, %rbx |
| movq VG_(tt_fast)@GOTPCREL(%rip), %rcx |
| movq (%rcx,%rbx,8), %rcx |
| cmpq %rax, (%rcx) |
| jnz fast_lookup_failed |
| /* increment bb profile counter */ |
| movq VG_(tt_fastN)@GOTPCREL(%rip), %rdx |
| movq (%rdx,%rbx,8), %rdx |
| incl (%rdx) |
| |
| /* Found a match. Call tce[1], which is 8 bytes along, since |
| each tce element is a 64-bit int. */ |
| addq $8, %rcx |
| call *%rcx |
| |
| /* |
| %rax holds destination (original) address. |
| %rbp indicates further details of the control transfer |
| requested to the address in %rax. |
| |
| If rbp is unchanged (== * 8(%rsp)), just jump next to %rax. |
| |
| Otherwise fall out, back to the scheduler, and let it |
| figure out what to do next. |
| */ |
| |
| cmpq 8(%rsp), %rbp |
| jz dispatch_boring |
| |
| jmp dispatch_exceptional |
| |
| |
| |
| /* All exits from the dispatcher go through here. %rax holds |
| the return value. |
| */ |
| run_innerloop_exit: |
| /* We're leaving. Check that nobody messed with |
| %mxcsr or %fpucw. We can't mess with %rax here as it |
| holds the tentative return value, but any other is OK. */ |
| pushq $0 |
| fstcw (%rsp) |
| cmpl $0x027F, (%rsp) |
| popq %r11 /* get rid of the word without trashing %eflags */ |
| jnz invariant_violation |
| pushq $0 |
| stmxcsr (%rsp) |
| andl $0xFFFFFFC0, (%rsp) /* mask out status flags */ |
| cmpl $0x1F80, (%rsp) |
| popq %r11 |
| jnz invariant_violation |
| /* otherwise we're OK */ |
| jmp run_innerloop_exit_REALLY |
| |
| invariant_violation: |
| movq $VG_TRC_INVARIANT_FAILED, %rax |
| jmp run_innerloop_exit_REALLY |
| |
| run_innerloop_exit_REALLY: |
| movq VG_(dispatch_ctr)@GOTPCREL(%rip), %rsi |
| popq (%rsi) |
| popq %rdi |
| popq %r15 |
| popq %r14 |
| popq %r13 |
| popq %r12 |
| popq %r11 |
| popq %r10 |
| popq %r9 |
| popq %r8 |
| popq %rbp |
| popq %rsi |
| popq %rdx |
| popq %rcx |
| popq %rbx |
| ret |
| |
| |
| |
| /* Other ways of getting out of the inner loop. Placed out-of-line to |
| make it look cleaner. |
| */ |
| dispatch_exceptional: |
| /* this is jumped to only, not fallen-through from above */ |
| |
| /* save %rax in %RIP and defer to sched */ |
| movq 8(%rsp), %rdi |
| movq %rax, OFFSET_amd64_RIP(%rdi) |
| movq %rbp, %rax |
| jmp run_innerloop_exit |
| |
| fast_lookup_failed: |
| /* %RIP is up to date here since dispatch_boring dominates */ |
| addl $1, 0(%rsp) |
| movq $VG_TRC_INNER_FASTMISS, %rax |
| jmp run_innerloop_exit |
| |
| counter_is_zero: |
| /* %RIP is up to date here since dispatch_boring dominates */ |
| addl $1, 0(%rsp) |
| movq $VG_TRC_INNER_COUNTERZERO, %rax |
| jmp run_innerloop_exit |
| |
| |
| /* Let the linker know we don't need an executable stack */ |
| .section .note.GNU-stack,"",@progbits |
| |
| ##--------------------------------------------------------------------## |
| ##--- end ---## |
| ##--------------------------------------------------------------------## |