; $Id: VMMR0JmpA-x86.asm 93115 2022-01-01 11:31:46Z vboxsync $ ;; @file ; VMM - R0 SetJmp / LongJmp routines for X86. ; ; ; Copyright (C) 2006-2022 Oracle Corporation ; ; This file is part of VirtualBox Open Source Edition (OSE), as ; available from http://www.virtualbox.org. This file is free software; ; you can redistribute it and/or modify it under the terms of the GNU ; General Public License (GPL) as published by the Free Software ; Foundation, in version 2 as it comes in the "COPYING" file of the ; VirtualBox OSE distribution. VirtualBox OSE is distributed in the ; hope that it will be useful, but WITHOUT ANY WARRANTY of any kind. ; ;******************************************************************************* ;* Header Files * ;******************************************************************************* %include "VBox/asmdefs.mac" %include "VMMInternal.mac" %include "VBox/err.mac" %include "VBox/param.mac" ;******************************************************************************* ;* Defined Constants And Macros * ;******************************************************************************* %define RESUME_MAGIC 07eadf00dh %define STACK_PADDING 0eeeeeeeeh BEGINCODE ;; ; The setjmp variant used for calling Ring-3. ; ; This differs from the normal setjmp in that it will resume VMMRZCallRing3 if we're ; in the middle of a ring-3 call. Another differences is the function pointer and ; argument. This has to do with resuming code and the stack frame of the caller. ; ; @returns VINF_SUCCESS on success or whatever is passed to vmmR0CallRing3LongJmp. ; @param pJmpBuf msc:rcx gcc:rdi x86:[esp+0x04] Our jmp_buf. ; @param pfn msc:rdx gcc:rsi x86:[esp+0x08] The function to be called when not resuming. ; @param pvUser1 msc:r8 gcc:rdx x86:[esp+0x0c] The argument of that function. ; @param pvUser2 msc:r9 gcc:rcx x86:[esp+0x10] The argument of that function. ; BEGINPROC vmmR0CallRing3SetJmp GLOBALNAME vmmR0CallRing3SetJmp2 GLOBALNAME vmmR0CallRing3SetJmpEx ; ; Save the registers. ; mov edx, [esp + 4h] ; pJmpBuf mov [xDX + VMMR0JMPBUF.ebx], ebx mov [xDX + VMMR0JMPBUF.esi], esi mov [xDX + VMMR0JMPBUF.edi], edi mov [xDX + VMMR0JMPBUF.ebp], ebp mov xAX, [esp] mov [xDX + VMMR0JMPBUF.eip], xAX lea ecx, [esp + 4] ; (used in resume) mov [xDX + VMMR0JMPBUF.esp], ecx pushf pop xAX mov [xDX + VMMR0JMPBUF.eflags], xAX ; ; If we're not in a ring-3 call, call pfn and return. ; test byte [xDX + VMMR0JMPBUF.fInRing3Call], 1 jnz .resume mov ebx, edx ; pJmpBuf -> ebx (persistent reg) %ifdef VMM_R0_SWITCH_STACK mov esi, [ebx + VMMR0JMPBUF.pvSavedStack] test esi, esi jz .entry_error %ifdef VBOX_STRICT cmp dword [esi], 0h jne .entry_error mov edx, esi mov edi, esi mov ecx, VMM_STACK_SIZE / 4 mov eax, STACK_PADDING repne stosd %endif lea esi, [esi + VMM_STACK_SIZE - 32] mov [esi + 1ch], dword 0deadbeefh ; Marker 1. mov [esi + 18h], ebx ; Save pJmpBuf pointer. mov [esi + 14h], dword 00c00ffeeh ; Marker 2. mov [esi + 10h], dword 0f00dbeefh ; Marker 3. mov edx, [esp + 10h] ; pvArg2 mov ecx, [esp + 0ch] ; pvArg1 mov eax, [esp + 08h] ; pfn %if 1 ; Use this to eat of some extra stack - handy for finding paths using lots of stack. %define FRAME_OFFSET 0 %else %define FRAME_OFFSET 1024 %endif mov [esi - FRAME_OFFSET + 04h], edx mov [esi - FRAME_OFFSET ], ecx lea esp, [esi - FRAME_OFFSET] ; Switch stack! call eax and dword [esi + 1ch], byte 0 ; reset marker. %ifdef VBOX_STRICT ; Calc stack usage and check for overflows. mov edi, [ebx + VMMR0JMPBUF.pvSavedStack] cmp dword [edi], STACK_PADDING ; Check for obvious stack overflow. jne .stack_overflow mov esi, eax ; save eax mov eax, STACK_PADDING mov ecx, VMM_STACK_SIZE / 4 cld repe scasd shl ecx, 2 ; *4 cmp ecx, VMM_STACK_SIZE - 64 ; Less than 64 bytes left -> overflow as well. mov eax, esi ; restore eax in case of overflow (esi remains used) jae .stack_overflow_almost ; Update stack usage statistics. cmp ecx, [ebx + VMMR0JMPBUF.cbUsedMax] ; New max usage? jle .no_used_max mov [ebx + VMMR0JMPBUF.cbUsedMax], ecx .no_used_max: ; To simplify the average stuff, just historize before we hit div errors. inc dword [ebx + VMMR0JMPBUF.cUsedTotal] test [ebx + VMMR0JMPBUF.cUsedTotal], dword 0c0000000h jz .no_historize mov dword [ebx + VMMR0JMPBUF.cUsedTotal], 2 mov edi, [ebx + VMMR0JMPBUF.cbUsedAvg] mov [ebx + VMMR0JMPBUF.cbUsedTotal], edi mov dword [ebx + VMMR0JMPBUF.cbUsedTotal + 4], 0 .no_historize: add [ebx + VMMR0JMPBUF.cbUsedTotal], ecx adc dword [ebx + VMMR0JMPBUF.cbUsedTotal + 4], 0 mov eax, [ebx + VMMR0JMPBUF.cbUsedTotal] mov edx, [ebx + VMMR0JMPBUF.cbUsedTotal + 4] mov edi, [ebx + VMMR0JMPBUF.cUsedTotal] div edi mov [ebx + VMMR0JMPBUF.cbUsedAvg], eax mov eax, esi ; restore eax (final, esi released) mov edi, [ebx + VMMR0JMPBUF.pvSavedStack] mov dword [edi], 0h ; Reset the overflow marker. %endif ; VBOX_STRICT %else ; !VMM_R0_SWITCH_STACK mov ecx, [esp + 0ch] ; pvArg1 mov edx, [esp + 10h] ; pvArg2 mov eax, [esp + 08h] ; pfn sub esp, 12 ; align the stack on a 16-byte boundary. mov [esp ], ecx mov [esp + 04h], edx call eax %endif ; !VMM_R0_SWITCH_STACK mov edx, ebx ; pJmpBuf -> edx (volatile reg) ; ; Return like in the long jump but clear eip, no short cuts here. ; .proper_return: mov ebx, [xDX + VMMR0JMPBUF.ebx] mov esi, [xDX + VMMR0JMPBUF.esi] mov edi, [xDX + VMMR0JMPBUF.edi] mov ebp, [xDX + VMMR0JMPBUF.ebp] mov xCX, [xDX + VMMR0JMPBUF.eip] and dword [xDX + VMMR0JMPBUF.eip], byte 0 ; used for valid check. mov esp, [xDX + VMMR0JMPBUF.esp] push dword [xDX + VMMR0JMPBUF.eflags] popf jmp xCX .entry_error: mov eax, VERR_VMM_SET_JMP_ERROR jmp .proper_return .stack_overflow: mov eax, VERR_VMM_SET_JMP_STACK_OVERFLOW mov edx, ebx jmp .proper_return .stack_overflow_almost: mov eax, VERR_VMM_SET_JMP_STACK_OVERFLOW mov edx, ebx jmp .proper_return ; ; Aborting resume. ; .bad: and dword [xDX + VMMR0JMPBUF.eip], byte 0 ; used for valid check. mov edi, [xDX + VMMR0JMPBUF.edi] mov esi, [xDX + VMMR0JMPBUF.esi] mov ebx, [xDX + VMMR0JMPBUF.ebx] mov eax, VERR_VMM_SET_JMP_ABORTED_RESUME ret ; ; Resume VMMRZCallRing3 the call. ; .resume: ; Sanity checks. %ifdef VMM_R0_SWITCH_STACK mov eax, [xDX + VMMR0JMPBUF.pvSavedStack] %ifdef RT_STRICT cmp dword [eax], STACK_PADDING %endif lea eax, [eax + VMM_STACK_SIZE - 32] cmp dword [eax + 1ch], 0deadbeefh ; Marker 1. jne .bad %ifdef RT_STRICT cmp [esi + 18h], edx ; The saved pJmpBuf pointer. jne .bad cmp dword [esi + 14h], 00c00ffeeh ; Marker 2. jne .bad cmp dword [esi + 10h], 0f00dbeefh ; Marker 3. jne .bad %endif %else ; !VMM_R0_SWITCH_STACK cmp ecx, [xDX + VMMR0JMPBUF.SpCheck] jne .bad .espCheck_ok: mov ecx, [xDX + VMMR0JMPBUF.cbSavedStack] cmp ecx, VMM_STACK_SIZE ja .bad test ecx, 3 jnz .bad mov edi, [xDX + VMMR0JMPBUF.esp] sub edi, [xDX + VMMR0JMPBUF.SpResume] cmp ecx, edi jne .bad %endif %ifdef VMM_R0_SWITCH_STACK ; Switch stack. mov esp, [xDX + VMMR0JMPBUF.SpResume] %else ; Restore the stack. mov ecx, [xDX + VMMR0JMPBUF.cbSavedStack] shr ecx, 2 mov esi, [xDX + VMMR0JMPBUF.pvSavedStack] mov edi, [xDX + VMMR0JMPBUF.SpResume] mov esp, edi rep movsd %endif ; !VMM_R0_SWITCH_STACK mov byte [xDX + VMMR0JMPBUF.fInRing3Call], 0 ; ; Continue where we left off. ; %ifdef VBOX_STRICT pop eax ; magic cmp eax, RESUME_MAGIC je .magic_ok mov ecx, 0123h mov [ecx], edx .magic_ok: %endif popf pop ebx pop esi pop edi pop ebp xor eax, eax ; VINF_SUCCESS ret ENDPROC vmmR0CallRing3SetJmp ;; ; Worker for VMMRZCallRing3. ; This will save the stack and registers. ; ; @param pJmpBuf msc:rcx gcc:rdi x86:[ebp+8] Pointer to the jump buffer. ; @param rc msc:rdx gcc:rsi x86:[ebp+c] The return code. ; BEGINPROC vmmR0CallRing3LongJmp ; ; Save the registers on the stack. ; push ebp mov ebp, esp push edi push esi push ebx pushf %ifdef VBOX_STRICT push RESUME_MAGIC %endif ; ; Load parameters. ; mov edx, [ebp + 08h] ; pJmpBuf mov eax, [ebp + 0ch] ; rc ; ; Is the jump buffer armed? ; cmp dword [xDX + VMMR0JMPBUF.eip], byte 0 je .nok ; ; Sanity checks. ; mov edi, [xDX + VMMR0JMPBUF.pvSavedStack] test edi, edi ; darwin may set this to 0. jz .nok mov [xDX + VMMR0JMPBUF.SpResume], esp %ifndef VMM_R0_SWITCH_STACK mov esi, esp mov ecx, [xDX + VMMR0JMPBUF.esp] sub ecx, esi ; two sanity checks on the size. cmp ecx, VMM_STACK_SIZE ; check max size. jnbe .nok ; ; Copy the stack. ; test ecx, 3 ; check alignment jnz .nok mov [xDX + VMMR0JMPBUF.cbSavedStack], ecx shr ecx, 2 rep movsd %endif ; !VMM_R0_SWITCH_STACK ; Save a PC here to assist unwinding. .unwind_point: mov dword [xDX + VMMR0JMPBUF.SavedEipForUnwind], .unwind_point mov ecx, [xDX + VMMR0JMPBUF.ebp] lea ecx, [ecx + 4] mov [xDX + VMMR0JMPBUF.UnwindRetPcLocation], ecx ; Save ESP & EBP to enable stack dumps mov ecx, ebp mov [xDX + VMMR0JMPBUF.SavedEbp], ecx sub ecx, 4 mov [xDX + VMMR0JMPBUF.SavedEsp], ecx ; store the last pieces of info. mov ecx, [xDX + VMMR0JMPBUF.esp] mov [xDX + VMMR0JMPBUF.SpCheck], ecx mov byte [xDX + VMMR0JMPBUF.fInRing3Call], 1 ; ; Do the long jump. ; mov ebx, [xDX + VMMR0JMPBUF.ebx] mov esi, [xDX + VMMR0JMPBUF.esi] mov edi, [xDX + VMMR0JMPBUF.edi] mov ebp, [xDX + VMMR0JMPBUF.ebp] mov ecx, [xDX + VMMR0JMPBUF.eip] mov [xDX + VMMR0JMPBUF.UnwindRetPcValue], ecx mov esp, [xDX + VMMR0JMPBUF.esp] push dword [xDX + VMMR0JMPBUF.eflags] popf jmp ecx ; ; Failure ; .nok: %ifdef VBOX_STRICT pop eax ; magic cmp eax, RESUME_MAGIC je .magic_ok mov ecx, 0123h mov [ecx], edx .magic_ok: %endif popf pop ebx pop esi pop edi mov eax, VERR_VMM_LONG_JMP_ERROR leave ret ENDPROC vmmR0CallRing3LongJmp