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Fixed a stack-size bug uncovered by a PUSH SS/POP SS sequence in Windows 95 kernel

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This commit is contained in:
Jeff Parsons 2015-09-11 15:13:08 -07:00
commit cb9e330cfa
4 changed files with 63 additions and 2 deletions
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29
modules/pcjs/lib/x86ops.js
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@ -126,6 +126,11 @@ X86.opADDAX = function ADDAX()
*/
X86.opPUSHES = function PUSHES()
{
/*
* TODO: Reportedly, when the OPERAND size is 32 bits, the 80386 will decrement the stack pointer by 4,
* write the selector into the 2 lower bytes, and leave the 2 upper bytes untouched, whereas we will write
* a 32-bit value, effectively zeroing the 2 upper bytes. Need to confirm this.
*/
this.pushWord(this.segES.sel);
this.nStepCycles -= this.cycleCounts.nOpCyclesPushSeg;
};
@ -137,6 +142,9 @@ X86.opPUSHES = function PUSHES()
*/
X86.opPOPES = function POPES()
{
/*
* As discussed in fnRETF(), we temporarily set opLSP around operations that fnFault() may need to restart.
*/
this.opLSP = this.regLSP;
this.setES(this.popWord());
this.nStepCycles -= this.cycleCounts.nOpCyclesPopReg;
@ -216,6 +224,11 @@ X86.opORAX = function ORAX()
*/
X86.opPUSHCS = function PUSHCS()
{
/*
* TODO: Reportedly, when the OPERAND size is 32 bits, the 80386 will decrement the stack pointer by 4,
* write the selector into the 2 lower bytes, and leave the 2 upper bytes untouched, whereas we will write
* a 32-bit value, effectively zeroing the 2 upper bytes. Need to confirm this.
*/
this.pushWord(this.segCS.sel);
this.nStepCycles -= this.cycleCounts.nOpCyclesPushSeg;
};
@ -314,6 +327,11 @@ X86.opADCAX = function ADCAX()
*/
X86.opPUSHSS = function PUSHSS()
{
/*
* TODO: Reportedly, when the OPERAND size is 32 bits, the 80386 will decrement the stack pointer by 4,
* write the selector into the 2 lower bytes, and leave the 2 upper bytes untouched, whereas we will write
* a 32-bit value, effectively zeroing the 2 upper bytes. Need to confirm this.
*/
this.pushWord(this.segSS.sel);
this.nStepCycles -= this.cycleCounts.nOpCyclesPushSeg;
};
@ -325,6 +343,9 @@ X86.opPUSHSS = function PUSHSS()
*/
X86.opPOPSS = function POPSS()
{
/*
* As discussed in fnRETF(), we temporarily set opLSP around operations that fnFault() may need to restart.
*/
this.opLSP = this.regLSP;
this.setSS(this.popWord());
this.nStepCycles -= this.cycleCounts.nOpCyclesPopReg;
@ -404,6 +425,11 @@ X86.opSBBAX = function SBBAX()
*/
X86.opPUSHDS = function PUSHDS()
{
/*
* TODO: Reportedly, when the OPERAND size is 32 bits, the 80386 will decrement the stack pointer by 4,
* write the selector into the 2 lower bytes, and leave the 2 upper bytes untouched, whereas we will write
* a 32-bit value, effectively zeroing the 2 upper bytes. Need to confirm this.
*/
this.pushWord(this.segDS.sel);
this.nStepCycles -= this.cycleCounts.nOpCyclesPushSeg;
};
@ -415,6 +441,9 @@ X86.opPUSHDS = function PUSHDS()
*/
X86.opPOPDS = function POPDS()
{
/*
* As discussed in fnRETF(), we temporarily set opLSP around operations that fnFault() may need to restart.
*/
this.opLSP = this.regLSP;
this.setDS(this.popWord());
this.nStepCycles -= this.cycleCounts.nOpCyclesPopReg;