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

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These generate a lot of false positives and nothing of value.
This commit is contained in:
Andreas Kling 2021-03-09 13:24:03 +01:00
parent a457b90733
commit 38fc522f5d
3 changed files with 20 additions and 1 deletions
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7
Userland/DevTools/UserspaceEmulator/Emulator.cpp
View file

@ -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;

12
Userland/DevTools/UserspaceEmulator/Emulator.h
View file

@ -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);
}

2
Userland/DevTools/UserspaceEmulator/MallocTracer.cpp
View file

@ -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;
}