creport: Skeleton reading of Code Regions.

stratosphere/creport/source/creport_code_info.cpp

@@ -0,0 +1,62 @@
+#include <switch.h>
+
+#include "creport_code_info.hpp"
+
+void CodeList::ReadCodeRegionsFromProcess(Handle debug_handle, u64 pc, u64 lr) {
+    u64 code_base;
+    
+    /* Guess that either PC or LR will point to a code region. This could be false. */
+    if (!TryFindCodeRegion(debug_handle, pc, &code_base) && !TryFindCodeRegion(debug_handle, lr, &code_base)) {
+        return;
+    }
+    
+    u64 cur_ptr = code_base;
+    while (this->code_count < max_code_count) {
+        MemoryInfo mi;
+        u32 pi;
+        if (R_FAILED(svcQueryDebugProcessMemory(&mi, &pi, debug_handle, cur_ptr))) {
+            break;
+        }
+        
+        if (mi.perm == Perm_Rx) {
+            /* TODO: Parse CodeInfo. */
+            this->code_count++;
+        }
+        
+        /* If we're out of readable memory, we're done reading code. */
+        if (mi.type == MemType_Unmapped || mi.type == MemType_Reserved) {
+            break;
+        }
+        
+        /* Verify we're not getting stuck in an infinite loop. */
+        if (mi.size == 0 || U64_MAX - mi.size <= cur_ptr) {
+            break;
+        }
+            
+        cur_ptr += mi.size;
+    }
+}
+
+bool CodeList::TryFindCodeRegion(Handle debug_handle, u64 guess, u64 *address) {
+    MemoryInfo mi;
+    u32 pi;
+    if (R_FAILED(svcQueryDebugProcessMemory(&mi, &pi, debug_handle, guess)) || mi.perm != Perm_Rx) {
+        return false;
+    }
+    
+    /* Iterate backwards until we find the memory before the code region. */
+    while (mi.addr > 0) {
+        if (R_FAILED(svcQueryDebugProcessMemory(&mi, &pi, debug_handle, guess))) {
+            return false;
+        }
+        
+        if (mi.type == MemType_Unmapped) {
+            /* Code region will be at the end of the unmapped region preceding it. */
+            *address = mi.addr + mi.size;
+            return true;
+        }
+        
+        guess -= 4;
+    }
+    return false;
+}