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Interpreter_SystemRegisters: Check processor privilege level in mfspr and mtspr 

If a program executing in user mode tries to write to any SPRs other than
XER, LR, or CTR registers, then a program exception occurs. Similarly
this also applies for reading SPRs as well, however the upper and lower
timebase halves can also be read (but not written to).
This commit is contained in:
Lioncash 2018-05-20 15:16:16 -04:00
parent 4284952538
commit 0337ca116a
1 changed files with 15 additions and 7 deletions
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22
Source/Core/Core/PowerPC/Interpreter/Interpreter_SystemRegisters.cpp
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@ -194,9 +194,13 @@ void Interpreter::mfspr(UGeckoInstruction inst)
{ {
const u32 index = ((inst.SPR & 0x1F) << 5) + ((inst.SPR >> 5) & 0x1F); const u32 index = ((inst.SPR & 0x1F) << 5) + ((inst.SPR >> 5) & 0x1F);
// TODO - check processor privilege level - many of these require privilege // XER, LR, CTR, and timebase halves are the only ones available in user mode.
// XER LR CTR are the only ones available in user mode, time base can be read too. if (MSR.PR && index != SPR_XER && index != SPR_LR && index != SPR_CTR && index != SPR_TL &&
// GameCube games always run in superuser mode, but hey.... index != SPR_TU)
{
PowerPC::ppcState.Exceptions |= EXCEPTION_PROGRAM;
return;
}
switch (index) switch (index)
{ {
@ -237,13 +241,17 @@ void Interpreter::mfspr(UGeckoInstruction inst)
void Interpreter::mtspr(UGeckoInstruction inst) void Interpreter::mtspr(UGeckoInstruction inst)
{ {
const u32 index = (inst.SPRU << 5) | (inst.SPRL & 0x1F); const u32 index = (inst.SPRU << 5) | (inst.SPRL & 0x1F);
// XER, LR, and CTR are the only ones available to be written to in user mode
if (MSR.PR && index != SPR_XER && index != SPR_LR && index != SPR_CTR)
{
PowerPC::ppcState.Exceptions |= EXCEPTION_PROGRAM;
return;
}
const u32 old_value = rSPR(index); const u32 old_value = rSPR(index);
rSPR(index) = rGPR[inst.RD]; rSPR(index) = rGPR[inst.RD];
// TODO - check processor privilege level - many of these require privilege
// XER LR CTR are the only ones available in user mode, time base can be read too.
// GameCube games always run in superuser mode, but hey....
// Our DMA emulation is highly inaccurate - instead of properly emulating the queue // Our DMA emulation is highly inaccurate - instead of properly emulating the queue
// and so on, we simply make all DMA:s complete instantaneously. // and so on, we simply make all DMA:s complete instantaneously.