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Revert "[asan] Optimize initialization order checking" #104098

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Revert "[asan] Optimize initialization order checking" #104098

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39 changes: 0 additions & 39 deletions compiler-rt/lib/asan/asan_globals.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -520,43 +520,6 @@ void __asan_before_dynamic_init(const char *module_name) {
current_dynamic_init_module_name = module_name;
}

// Maybe SANITIZER_CAN_USE_PREINIT_ARRAY is to conservative for `.init_array`,
// however we should not make mistake here. If `UnpoisonBeforeMain` was not
// executed at all we will have false reports on globals.
#if SANITIZER_CAN_USE_PREINIT_ARRAY
// This optimization aims to reduce the overhead of `__asan_after_dynamic_init`
// calls by leveraging incremental unpoisoning/poisoning in
// `__asan_before_dynamic_init`. We expect most `__asan_after_dynamic_init
// calls` to be no-ops. However, to ensure all globals are unpoisoned before the
// `main`, we force `UnpoisonBeforeMain` to fully execute
// `__asan_after_dynamic_init`.

// With lld, `UnpoisonBeforeMain` runs after standard `.init_array`, making it
// the final `__asan_after_dynamic_init` call for the static runtime. In
// contrast, GNU ld executes it earlier, causing subsequent
// `__asan_after_dynamic_init` calls to perform full unpoisoning, losing the
// optimization.
bool allow_after_dynamic_init SANITIZER_GUARDED_BY(mu_for_globals) = false;

static void UnpoisonBeforeMain(void) {
{
Lock lock(&mu_for_globals);
if (allow_after_dynamic_init)
return;
allow_after_dynamic_init = true;
}
if (flags()->report_globals >= 3)
Printf("UnpoisonBeforeMain\n");
__asan_after_dynamic_init();
}

__attribute__((section(".init_array.65537"), used)) static void (
*asan_after_init_array)(void) = UnpoisonBeforeMain;
#else
// Incremental poisoning is disabled, unpoison globals immediately.
static constexpr bool allow_after_dynamic_init = true;
#endif // SANITIZER_CAN_USE_PREINIT_ARRAY

// This method runs immediately after dynamic initialization in each TU, when
// all dynamically initialized globals except for those defined in the current
// TU are poisoned. It simply unpoisons all dynamically initialized globals.
Expand All @@ -565,8 +528,6 @@ void __asan_after_dynamic_init() {
return;
CHECK(AsanInited());
Lock lock(&mu_for_globals);
if (!allow_after_dynamic_init)
return;
if (!current_dynamic_init_module_name)
return;

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14 changes: 0 additions & 14 deletions compiler-rt/test/asan/TestCases/Linux/initialization-nobug-lld.cpp
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14 changes: 5 additions & 9 deletions compiler-rt/test/asan/TestCases/initialization-nobug.cpp
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Original file line number Diff line number Diff line change
@@ -1,10 +1,10 @@
// A collection of various initializers which shouldn't trip up initialization
// order checking. If successful, this will just return 0.

// RUN: %clangxx_asan -O0 %s %p/Helpers/initialization-nobug-extra.cpp -o %t && %env_asan_opts=check_initialization_order=true:report_globals=3 %run %t 2>&1 | FileCheck %s --implicit-check-not "DynInitPoison"
// RUN: %clangxx_asan -O1 %s %p/Helpers/initialization-nobug-extra.cpp -o %t && %env_asan_opts=check_initialization_order=true:report_globals=3 %run %t 2>&1 | FileCheck %s --implicit-check-not "DynInitPoison"
// RUN: %clangxx_asan -O2 %s %p/Helpers/initialization-nobug-extra.cpp -o %t && %env_asan_opts=check_initialization_order=true:report_globals=3 %run %t 2>&1 | FileCheck %s --implicit-check-not "DynInitPoison"
// RUN: %clangxx_asan -O3 %s %p/Helpers/initialization-nobug-extra.cpp -o %t && %env_asan_opts=check_initialization_order=true:report_globals=3 %run %t 2>&1 | FileCheck %s --implicit-check-not "DynInitPoison"
// RUN: %clangxx_asan -O0 %s %p/Helpers/initialization-nobug-extra.cpp -o %t && %env_asan_opts=check_initialization_order=true:report_globals=3 %run %t 2>&1 | FileCheck %s --implicit-check-not "DynInit"
// RUN: %clangxx_asan -O1 %s %p/Helpers/initialization-nobug-extra.cpp -o %t && %env_asan_opts=check_initialization_order=true:report_globals=3 %run %t 2>&1 | FileCheck %s --implicit-check-not "DynInit"
// RUN: %clangxx_asan -O2 %s %p/Helpers/initialization-nobug-extra.cpp -o %t && %env_asan_opts=check_initialization_order=true:report_globals=3 %run %t 2>&1 | FileCheck %s --implicit-check-not "DynInit"
// RUN: %clangxx_asan -O3 %s %p/Helpers/initialization-nobug-extra.cpp -o %t && %env_asan_opts=check_initialization_order=true:report_globals=3 %run %t 2>&1 | FileCheck %s --implicit-check-not "DynInit"

// Simple access:
// Make sure that accessing a global in the same TU is safe
Expand Down Expand Up @@ -44,10 +44,6 @@ int getStructWithDtorValue() { return struct_with_dtor.value; }
int main() { return 0; }

// CHECK: DynInitPoison
// CHECK: DynInitUnpoison
// CHECK: DynInitPoison

// In general case entire set of DynInitPoison must be followed by at lest one
// DynInitUnpoison. In some cases we can limit the number of DynInitUnpoison,
// see initialization-nobug-lld.cpp.

// CHECK: DynInitUnpoison
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