[PATCH v3 0/3] MR706: Draft: ntoskrnl: implement cmp instruction with opcodes 0x38,0x39
fixes bug #48988 I am not very familiar with assembly, so feedback is appreciated -- v3: fix print formatting https://gitlab.winehq.org/wine/wine/-/merge_requests/706
From: Etaash Mathamsetty <etaash.mathamsetty(a)gmail.com> with opcode 0x38 and 0x39 --- dlls/ntoskrnl.exe/instr.c | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) diff --git a/dlls/ntoskrnl.exe/instr.c b/dlls/ntoskrnl.exe/instr.c index 8f1aa4d45a3..c9c61513a33 100644 --- a/dlls/ntoskrnl.exe/instr.c +++ b/dlls/ntoskrnl.exe/instr.c @@ -890,7 +890,39 @@ static DWORD emulate_instruction( EXCEPTION_RECORD *rec, CONTEXT *context ) } break; /* Unable to emulate it */ } + case 0x38: + case 0x39: /* cmp r/m r/m*/ + { + BYTE *data = INSTR_GetOperandAddr(context, instr + 1, prefixlen + 1, long_addr, rex, segprefix, &len); + BYTE *data2 = INSTR_GetOperandAddr(context, instr + 2, prefixlen + 2, long_addr, rex, segprefix, &len); + SIZE_T offset = data - user_shared_data; + SIZE_T offset2 = data2 - user_shared_data; + SIZE_T data_size = get_op_size(long_op, rex); + if(offset <= KSHARED_USER_DATA_PAGE_SIZE - data_size) + { + if(offset2 <= KSHARED_USER_DATA_PAGE_SIZE - data_size) + { + data2 = wine_user_shared_data + offset2; + TRACE("USD offset2 %#x at %#p", (unsigned int)offset, (void*)context->Rip); + } + TRACE("USD offset %#x at %#p\n",(unsigned int) offset, (void*)context->Rip); + + /* clear ZF and CF */ + context->EFlags &= ~(1UL << 6); + context->EFlags &= ~(1UL); + if(*(wine_user_shared_data + offset) == *data2) + { + context->EFlags |= (1UL << 6); /* ZF */ + } + else if(*(wine_user_shared_data + offset) < *data2){ + context->EFlags |= 1UL; /* CF */ + } + context->Rip += prefixlen + len + 1; + return ExceptionContinueExecution; + } + break; + } case 0xa0: /* mov Ob, AL */ case 0xa1: /* mov Ovqp, rAX */ { -- GitLab https://gitlab.winehq.org/wine/wine/-/merge_requests/706
From: Etaash Mathamsetty <etaash.mathamsetty(a)gmail.com> --- dlls/ntoskrnl.exe/instr.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/dlls/ntoskrnl.exe/instr.c b/dlls/ntoskrnl.exe/instr.c index c9c61513a33..dfb79830b7a 100644 --- a/dlls/ntoskrnl.exe/instr.c +++ b/dlls/ntoskrnl.exe/instr.c @@ -893,8 +893,10 @@ static DWORD emulate_instruction( EXCEPTION_RECORD *rec, CONTEXT *context ) case 0x38: case 0x39: /* cmp r/m r/m*/ { - BYTE *data = INSTR_GetOperandAddr(context, instr + 1, prefixlen + 1, long_addr, rex, segprefix, &len); - BYTE *data2 = INSTR_GetOperandAddr(context, instr + 2, prefixlen + 2, long_addr, rex, segprefix, &len); + BYTE* data = NULL; + BYTE* data2 = NULL; + data = INSTR_GetOperandAddr(context, instr + 1, prefixlen + 1, long_addr, rex, segprefix, &len); + data2 = INSTR_GetOperandAddr(context, instr + 2, prefixlen + 2, long_addr, rex, segprefix, &len); SIZE_T offset = data - user_shared_data; SIZE_T offset2 = data2 - user_shared_data; SIZE_T data_size = get_op_size(long_op, rex); -- GitLab https://gitlab.winehq.org/wine/wine/-/merge_requests/706
From: Etaash Mathamsetty <etaash.mathamsetty(a)gmail.com> --- dlls/ntoskrnl.exe/instr.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/dlls/ntoskrnl.exe/instr.c b/dlls/ntoskrnl.exe/instr.c index dfb79830b7a..b4c646bb3b2 100644 --- a/dlls/ntoskrnl.exe/instr.c +++ b/dlls/ntoskrnl.exe/instr.c @@ -905,9 +905,9 @@ static DWORD emulate_instruction( EXCEPTION_RECORD *rec, CONTEXT *context ) if(offset2 <= KSHARED_USER_DATA_PAGE_SIZE - data_size) { data2 = wine_user_shared_data + offset2; - TRACE("USD offset2 %#x at %#p", (unsigned int)offset, (void*)context->Rip); + TRACE("USD offset2 %#x at %p", (unsigned int)offset, (void*)context->Rip); } - TRACE("USD offset %#x at %#p\n",(unsigned int) offset, (void*)context->Rip); + TRACE("USD offset %#x at %p\n",(unsigned int) offset, (void*)context->Rip); /* clear ZF and CF */ context->EFlags &= ~(1UL << 6); -- GitLab https://gitlab.winehq.org/wine/wine/-/merge_requests/706
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