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fake page dirtying in some cases for memory reads if later writes can not be caught

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Imported-from: https://svn.code.sf.net/p/dosbox/code-0/dosbox/trunk@3242
This commit is contained in:
Sebastian Strohhäcker 2008-12-04 21:09:32 +00:00
parent 4652da4af5
commit 8b56a6db1f
1 changed files with 24 additions and 9 deletions
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33
src/cpu/paging.cpp
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@ -16,7 +16,7 @@
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
/* $Id: paging.cpp,v 1.34 2008-05-18 13:11:14 c2woody Exp $ */
/* $Id: paging.cpp,v 1.35 2008-12-04 21:09:32 c2woody Exp $ */
#include <stdlib.h>
#include <assert.h>
@ -58,7 +58,7 @@ Bitu PageHandler::readd(PhysPt addr) {
void PageHandler::writeb(PhysPt addr,Bitu /*val*/) {
E_Exit("No byte handler for write to %d",addr);
};
}
void PageHandler::writew(PhysPt addr,Bitu val) {
writeb(addr+0,(Bit8u) (val >> 0));
@ -69,7 +69,7 @@ void PageHandler::writed(PhysPt addr,Bitu val) {
writeb(addr+1,(Bit8u) (val >> 8));
writeb(addr+2,(Bit8u) (val >> 16));
writeb(addr+3,(Bit8u) (val >> 24));
};
}
HostPt PageHandler::GetHostReadPt(Bitu /*phys_page*/) {
return 0;
@ -227,6 +227,7 @@ static INLINE bool InitPageCheckPresence_CheckOnly(PhysPt lin_addr,bool writing,
return true;
}
// check if a user-level memory access would trigger a privilege page fault
static INLINE bool InitPage_CheckUseraccess(Bitu u1,Bitu u2) {
switch (CPU_ArchitectureType) {
case CPU_ARCHTYPE_MIXED:
@ -348,6 +349,7 @@ public:
}
}
if ((entry.block.wr==0) || (table.block.wr==0)) {
// page is write-protected for user mode
if (priv_check==0) {
switch (CPU_ArchitectureType) {
case CPU_ARCHTYPE_MIXED:
@ -363,6 +365,7 @@ public:
break;
}
}
// check if actually failing the write-protected check
if (writing && USERWRITE_PROHIBITED) priv_check=3;
}
if (priv_check==3) {
@ -373,17 +376,28 @@ public:
}
if (!table.block.a) {
table.block.a=1; //Set access
table.block.a=1; // set page table accessed
phys_writed((paging.base.page<<12)+(lin_page >> 10)*4,table.load);
}
if ((!entry.block.a) || (!entry.block.d)) {
entry.block.a=1; //Set access
if (writing) entry.block.d=1; //Set dirty
entry.block.a=1; // set page accessed
// page is dirty if we're writing to it, or if we're reading but the
// page will be fully linked so we can't track later writes
if (writing || (priv_check==0)) entry.block.d=1; // mark page as dirty
phys_writed((table.block.base<<12)+(lin_page & 0x3ff)*4,entry.load);
}
phys_page=entry.block.base;
if (priv_check==0) PAGING_LinkPage(lin_page,phys_page);
else {
// now see how the page should be linked best, if we need to catch privilege
// checks later on it should be linked as read-only page
if (priv_check==0) {
// if reading we could link the page as read-only to later cacth writes,
// will slow down pretty much but allows catching all dirty events
PAGING_LinkPage(lin_page,phys_page);
} else {
if (priv_check==1) {
PAGING_LinkPage(lin_page,phys_page);
return 1;
@ -754,12 +768,13 @@ void PAGING_ClearTLB(void) {
}
void PAGING_UnlinkPages(Bitu lin_page,Bitu pages) {
tlb_entry *entry = get_tlb_entry(lin_page<<12);
for (;pages>0;pages--) {
tlb_entry *entry = get_tlb_entry(lin_page<<12);
entry->read=0;
entry->write=0;
entry->readhandler=&init_page_handler;
entry->writehandler=&init_page_handler;
lin_page++;
}
}