implement w^x

noahw2021 · Dec 26, 2023 · 3f5dcba · 3f5dcba
1 parent 1ae45b3
commit 3f5dcba
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Showing 3 changed files with 12 additions and 6 deletions.
diff --git a/...proj/project.xcworkspace/xcuserdata/noahwooten.xcuserdatad/UserInterfaceState.xcuserstate b/...proj/project.xcworkspace/xcuserdata/noahwooten.xcuserdatad/UserInterfaceState.xcuserstate
diff --git a/plasm2_emu/cpu/mmu/mmu.h b/plasm2_emu/cpu/mmu/mmu.h
@@ -46,9 +46,9 @@ typedef struct _MMU_CTX {
 		union {
 			WORD64 Permissions;
 			struct {
-                WORD64 Execute : 1;
+                WORD64 Secure : 1;
+                WORD64 Selector : 1; // 0 = W, 1 = X
                 WORD64 Read : 1;
-                WORD64 Write : 1;
                 WORD64 Active : 1;
 			};
 		};

diff --git a/plasm2_emu/cpu/mmu/mmu_virt.c b/plasm2_emu/cpu/mmu/mmu_virt.c
@@ -18,10 +18,16 @@ WORD64 MmuTranslate(WORD64 VirtualAddress, BYTE Reason, WORD64 MaxSize) {
                 if (!(EmuCtx->Flags & EMUFLAG_NOSECURE)) {
                     if ((Reason & REASON_READ) && !MmuCtx->Pages[p].Read)
                         return 0;
-                    if ((Reason & REASON_WRTE) && !MmuCtx->Pages[p].Write)
-                        return 0;
-                    if ((Reason & REASON_EXEC) && !MmuCtx->Pages[p].Execute)
-                        return 0;
+                    if ((Reason & (REASON_WRTE | REASON_EXEC))) {
+                        if (!MmuCtx->Pages[p].Secure)
+                            return 0;
+
+                        if (MmuCtx->Pages[p].Selector && (Reason & REASON_WRTE))
+                            return 0;
+                        if (!MmuCtx->Pages[p].Selector && (Reason & REASON_EXEC))
+                            return 0;
+                    }
+
                     if (MaxSize != SIZE_WATCHDOG) {
                         if (VirtualAddress + MaxSize >= (MmuCtx->Pages[p].Virtual + MmuCtx->Pages[p].Size))
                             return 0;