[PATCH v11 0/9] MR706: Draft: ntoskrnl: implement cmp instruction with opcodes 0x38,0x39
fixes bug #48988 I am not very familiar with assembly, so feedback is appreciated
-- v11: improve formatting check correct number of bytes fix missing newline remove extra space fix errors fix potential logic error fix print formatting maybe fixes error? implement cmp instruction
From: Etaash Mathamsetty etaash.mathamsetty@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 */ {
From: Etaash Mathamsetty etaash.mathamsetty@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);
From: Etaash Mathamsetty etaash.mathamsetty@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);
From: Etaash Mathamsetty etaash.mathamsetty@gmail.com
--- dlls/ntoskrnl.exe/instr.c | 31 +++++++++++++++++-------------- 1 file changed, 17 insertions(+), 14 deletions(-)
diff --git a/dlls/ntoskrnl.exe/instr.c b/dlls/ntoskrnl.exe/instr.c index b4c646bb3b2..55a3ea8d0d3 100644 --- a/dlls/ntoskrnl.exe/instr.c +++ b/dlls/ntoskrnl.exe/instr.c @@ -893,31 +893,34 @@ static DWORD emulate_instruction( EXCEPTION_RECORD *rec, CONTEXT *context ) case 0x38: case 0x39: /* cmp r/m r/m*/ { - 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); + 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); + BOOL is_user_shared_data = FALSE; 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 */ + TRACE("USD offset %#x at %p\n",(unsigned int) offset, (void*) context->Rip); + data = wine_user_shared_data + offset; + is_user_shared_data = TRUE; + } + if(offset2 <= KSHARED_USER_DATA_PAGE_SIZE - data_size) + { + TRACE("USD offset %#x at %p", (unsigned int) offset2, (void*) context->Rip); + data2 = wine_user_shared_data + offset2; + is_user_shared_data = TRUE; + } + if(is_user_shared_data){ + /* clear ZF and CF */ context->EFlags &= ~(1UL << 6); context->EFlags &= ~(1UL);
- if(*(wine_user_shared_data + offset) == *data2) + if(*data == *data2) { context->EFlags |= (1UL << 6); /* ZF */ } - else if(*(wine_user_shared_data + offset) < *data2){ + else if(*data < *data2){ context->EFlags |= 1UL; /* CF */ } context->Rip += prefixlen + len + 1;
From: Etaash Mathamsetty etaash.mathamsetty@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 55a3ea8d0d3..36a1f9c93aa 100644 --- a/dlls/ntoskrnl.exe/instr.c +++ b/dlls/ntoskrnl.exe/instr.c @@ -902,13 +902,13 @@ static DWORD emulate_instruction( EXCEPTION_RECORD *rec, CONTEXT *context ) if(offset <= KSHARED_USER_DATA_PAGE_SIZE - data_size) { TRACE("USD offset %#x at %p\n",(unsigned int) offset, (void*) context->Rip); - data = wine_user_shared_data + offset; + data = (BYTE*)(wine_user_shared_data + offset); is_user_shared_data = TRUE; } if(offset2 <= KSHARED_USER_DATA_PAGE_SIZE - data_size) { TRACE("USD offset %#x at %p", (unsigned int) offset2, (void*) context->Rip); - data2 = wine_user_shared_data + offset2; + data2 = (BYTE*)(wine_user_shared_data + offset2); is_user_shared_data = TRUE; } if(is_user_shared_data){
From: Etaash Mathamsetty etaash.mathamsetty@gmail.com
--- dlls/ntoskrnl.exe/instr.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/dlls/ntoskrnl.exe/instr.c b/dlls/ntoskrnl.exe/instr.c index 36a1f9c93aa..b7682fe9afc 100644 --- a/dlls/ntoskrnl.exe/instr.c +++ b/dlls/ntoskrnl.exe/instr.c @@ -912,7 +912,7 @@ static DWORD emulate_instruction( EXCEPTION_RECORD *rec, CONTEXT *context ) is_user_shared_data = TRUE; } if(is_user_shared_data){ - /* clear ZF and CF */ + /* clear ZF and CF */ context->EFlags &= ~(1UL << 6); context->EFlags &= ~(1UL);
From: Etaash Mathamsetty etaash.mathamsetty@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 b7682fe9afc..2205def6be5 100644 --- a/dlls/ntoskrnl.exe/instr.c +++ b/dlls/ntoskrnl.exe/instr.c @@ -891,7 +891,7 @@ static DWORD emulate_instruction( EXCEPTION_RECORD *rec, CONTEXT *context ) break; /* Unable to emulate it */ } case 0x38: - case 0x39: /* cmp r/m r/m*/ + 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); @@ -907,7 +907,7 @@ static DWORD emulate_instruction( EXCEPTION_RECORD *rec, CONTEXT *context ) } if(offset2 <= KSHARED_USER_DATA_PAGE_SIZE - data_size) { - TRACE("USD offset %#x at %p", (unsigned int) offset2, (void*) context->Rip); + TRACE("USD offset %#x at %p\n", (unsigned int) offset2, (void*) context->Rip); data2 = (BYTE*)(wine_user_shared_data + offset2); is_user_shared_data = TRUE; }
From: Etaash Mathamsetty etaash.mathamsetty@gmail.com
might be an issue? --- dlls/ntoskrnl.exe/instr.c | 26 +++++++++++++++++--------- 1 file changed, 17 insertions(+), 9 deletions(-)
diff --git a/dlls/ntoskrnl.exe/instr.c b/dlls/ntoskrnl.exe/instr.c index 2205def6be5..0122672e9fb 100644 --- a/dlls/ntoskrnl.exe/instr.c +++ b/dlls/ntoskrnl.exe/instr.c @@ -893,34 +893,42 @@ 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); - SIZE_T offset = data - user_shared_data; - SIZE_T offset2 = data2 - user_shared_data; + ULONG64* data = (ULONG64*)INSTR_GetOperandAddr(context, instr + 1, prefixlen + 1, long_addr, rex, segprefix, &len); + ULONG64* data2 = (ULONG64*)INSTR_GetOperandAddr(context, instr + 2, prefixlen + 2, long_addr, rex, segprefix, &len); + SIZE_T offset = (BYTE*)data - user_shared_data; + SIZE_T offset2 = (BYTE*)data2 - user_shared_data; SIZE_T data_size = get_op_size(long_op, rex); BOOL is_user_shared_data = FALSE; + ULONG64 cmp1, cmp2, bitmask; if(offset <= KSHARED_USER_DATA_PAGE_SIZE - data_size) { TRACE("USD offset %#x at %p\n",(unsigned int) offset, (void*) context->Rip); - data = (BYTE*)(wine_user_shared_data + offset); + data = (ULONG64*)(wine_user_shared_data + offset); is_user_shared_data = TRUE; } if(offset2 <= KSHARED_USER_DATA_PAGE_SIZE - data_size) { TRACE("USD offset %#x at %p\n", (unsigned int) offset2, (void*) context->Rip); - data2 = (BYTE*)(wine_user_shared_data + offset2); + data2 = (ULONG64*)(wine_user_shared_data + offset2); is_user_shared_data = TRUE; } - if(is_user_shared_data){ + if(is_user_shared_data) + { /* clear ZF and CF */ context->EFlags &= ~(1UL << 6); context->EFlags &= ~(1UL);
- if(*data == *data2) + bitmask = ((1ULL << (8 * data_size)) - 1); + /* FIXME("bitmask %llx\n", bitmask); */ + + cmp1 = (*data) & bitmask; + cmp2 = (*data2) & bitmask; + + if(cmp1 == cmp2) { context->EFlags |= (1UL << 6); /* ZF */ } - else if(*data < *data2){ + else if(cmp1 < cmp2){ context->EFlags |= 1UL; /* CF */ } context->Rip += prefixlen + len + 1;
From: Etaash Mathamsetty etaash.mathamsetty@gmail.com
--- dlls/ntoskrnl.exe/instr.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/dlls/ntoskrnl.exe/instr.c b/dlls/ntoskrnl.exe/instr.c index 0122672e9fb..33ade6799ab 100644 --- a/dlls/ntoskrnl.exe/instr.c +++ b/dlls/ntoskrnl.exe/instr.c @@ -925,12 +925,10 @@ static DWORD emulate_instruction( EXCEPTION_RECORD *rec, CONTEXT *context ) cmp2 = (*data2) & bitmask;
if(cmp1 == cmp2) - { context->EFlags |= (1UL << 6); /* ZF */ - } - else if(cmp1 < cmp2){ + else if(cmp1 < cmp2) context->EFlags |= 1UL; /* CF */ - } + context->Rip += prefixlen + len + 1; return ExceptionContinueExecution; }
-
Etaash Mathamsetty -
Etaash Mathamsetty (＠etaash.mathamsetty)