UserspaceEmulator: Don't audit accesses in calloc() and libsystem.so

These generate a lot of false positives and nothing of value.

Userland/DevTools/UserspaceEmulator/Emulator.cpp

@@ -1057,6 +1057,10 @@ u32 Emulator::virt$mmap(u32 params_addr)
             bool rc = find_malloc_symbols(*region);
             VERIFY(rc);
         }
+        if (region->name() == "libsystem.so: .text") {
+            m_libsystem_start = final_address;
+            m_libsystem_end = final_address + final_size;
+        }
         mmu().add_region(move(region));
     }
 
@@ -1818,6 +1822,7 @@ bool Emulator::find_malloc_symbols(const MmapRegion& libc_text)
     auto malloc_symbol = image.find_demangled_function("malloc");
     auto free_symbol = image.find_demangled_function("free");
     auto realloc_symbol = image.find_demangled_function("realloc");
+    auto calloc_symbol = image.find_demangled_function("calloc");
     auto malloc_size_symbol = image.find_demangled_function("malloc_size");
     if (!malloc_symbol.has_value() || !free_symbol.has_value() || !realloc_symbol.has_value() || !malloc_size_symbol.has_value())
         return false;
@@ -1828,6 +1833,8 @@ bool Emulator::find_malloc_symbols(const MmapRegion& libc_text)
     m_free_symbol_end = m_free_symbol_start + free_symbol.value().size();
     m_realloc_symbol_start = realloc_symbol.value().value() + libc_text.base();
     m_realloc_symbol_end = m_realloc_symbol_start + realloc_symbol.value().size();
+    m_calloc_symbol_start = calloc_symbol.value().value() + libc_text.base();
+    m_calloc_symbol_end = m_calloc_symbol_start + calloc_symbol.value().size();
     m_malloc_size_symbol_start = malloc_size_symbol.value().value() + libc_text.base();
     m_malloc_size_symbol_end = m_malloc_size_symbol_start + malloc_size_symbol.value().size();
     return true;

Userland/DevTools/UserspaceEmulator/Emulator.h

@@ -64,6 +64,7 @@ public:
 
     bool is_in_malloc_or_free() const;
     bool is_in_loader_code() const;
+    bool is_in_libsystem() const;
 
     void did_receive_signal(int signum) { m_pending_signals |= (1 << signum); }
 
@@ -189,11 +190,16 @@ private:
     FlatPtr m_malloc_symbol_end { 0 };
     FlatPtr m_realloc_symbol_start { 0 };
     FlatPtr m_realloc_symbol_end { 0 };
+    FlatPtr m_calloc_symbol_start { 0 };
+    FlatPtr m_calloc_symbol_end { 0 };
     FlatPtr m_free_symbol_start { 0 };
     FlatPtr m_free_symbol_end { 0 };
     FlatPtr m_malloc_size_symbol_start { 0 };
     FlatPtr m_malloc_size_symbol_end { 0 };
 
+    FlatPtr m_libsystem_start { 0 };
+    FlatPtr m_libsystem_end { 0 };
+
     sigset_t m_pending_signals { 0 };
     sigset_t m_signal_mask { 0 };
 
@@ -218,11 +224,17 @@ private:
     RangeAllocator m_range_allocator;
 };
 
+ALWAYS_INLINE bool Emulator::is_in_libsystem() const
+{
+    return m_cpu.base_eip() >= m_libsystem_start && m_cpu.base_eip() < m_libsystem_end;
+}
+
 ALWAYS_INLINE bool Emulator::is_in_malloc_or_free() const
 {
     return (m_cpu.base_eip() >= m_malloc_symbol_start && m_cpu.base_eip() < m_malloc_symbol_end)
         || (m_cpu.base_eip() >= m_free_symbol_start && m_cpu.base_eip() < m_free_symbol_end)
         || (m_cpu.base_eip() >= m_realloc_symbol_start && m_cpu.base_eip() < m_realloc_symbol_end)
+        || (m_cpu.base_eip() >= m_calloc_symbol_start && m_cpu.base_eip() < m_calloc_symbol_end)
         || (m_cpu.base_eip() >= m_malloc_size_symbol_start && m_cpu.base_eip() < m_malloc_size_symbol_end);
 }
 

Userland/DevTools/UserspaceEmulator/MallocTracer.cpp

@@ -214,7 +214,7 @@ void MallocTracer::audit_read(const Region& region, FlatPtr address, size_t size
     if (!m_auditing_enabled)
         return;
 
-    if (m_emulator.is_in_malloc_or_free()) {
+    if (m_emulator.is_in_malloc_or_free() || m_emulator.is_in_libsystem()) {
         return;
     }