// Tests that __msan_unpoison_param() works as specified. To prevent MSan
// instrumentation from modifying parameter shadow before each call to foo(), we
// compile main() without MSan.
// RUN: %clangxx_msan -fno-sanitize=memory -c %s -o %t-main.o
// RUN: %clangxx_msan -fno-sanitize-memory-param-retval %t-main.o %s -o %t
// RUN: %run %t
#include <assert.h>
#include <sanitizer/msan_interface.h>
#if __has_feature(memory_sanitizer)
__attribute__((noinline)) int bar(int a, int b) {
volatile int zero = 0;
return zero;
}
int foo(int a, int b, int unpoisoned_params) {
if (unpoisoned_params == 0) {
assert(__msan_test_shadow(&a, sizeof(a)) == 0);
assert(__msan_test_shadow(&b, sizeof(b)) == 0);
} else if (unpoisoned_params == 1) {
assert(__msan_test_shadow(&a, sizeof(a)) == -1);
assert(__msan_test_shadow(&b, sizeof(b)) == 0);
} else if (unpoisoned_params == 2) {
assert(__msan_test_shadow(&a, sizeof(a)) == -1);
assert(__msan_test_shadow(&b, sizeof(b)) == -1);
}
// Poisons parameter shadow in TLS so that the next call from uninstrumented
// main has params 1 and 2 poisoned no matter what.
int x, y;
return bar(x, y);
}
#else
int foo(int, int, int);
int main() {
foo(0, 0, 2); // Poison parameters for next call.
foo(0, 0, 0); // Check that both params are poisoned.
__msan_unpoison_param(1);
foo(0, 0, 1); // Check that only first param is unpoisoned.
__msan_unpoison_param(2);
foo(0, 0, 2); // Check that first and second params are unpoisoned.
return 0;
}
#endif