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void __init_cpu_features_resolver(unsigned long hwcap,
const __ifunc_arg_t *arg) {
if (__aarch64_cpu_features.features)
return;
// ifunc resolvers don't have hwcaps in arguments on Android API lower
// than 30. If so, set feature detection done and keep all CPU features
// unsupported (zeros). To detect this case in runtime we check existence
// of memfd_create function from Standard C library which was introduced in
// Android API 30.
int memfd_create(const char *, unsigned int) __attribute__((weak));
if (!memfd_create)
return;
__init_cpu_features_constructor(hwcap, arg);
}
void CONSTRUCTOR_ATTRIBUTE __init_cpu_features(void) {
// CPU features already initialized.
if (__aarch64_cpu_features.features)
return;
// Don't set any CPU features,
// detection could be wrong on Exynos 9810.
if (__isExynos9810())
return;
unsigned long hwcap = getauxval(AT_HWCAP);
unsigned long hwcap2 = getauxval(AT_HWCAP2);
__ifunc_arg_t arg;
arg._size = sizeof(__ifunc_arg_t);
arg._hwcap = hwcap;
arg._hwcap2 = hwcap2;
__init_cpu_features_constructor(hwcap | _IFUNC_ARG_HWCAP, &arg);
}
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