12345678910111213141516171819202122232425262728 |
- #include <string.h>
- #include <sys/auxv.h>
- #include <sys/system_properties.h>
- static bool __isExynos9810(void) {
- char arch[PROP_VALUE_MAX];
- return __system_property_get("ro.arch", arch) > 0 &&
- strncmp(arch, "exynos9810", sizeof("exynos9810") - 1) == 0;
- }
- static void CONSTRUCTOR_ATTRIBUTE init_have_lse_atomics(void) {
- unsigned long hwcap = getauxval(AT_HWCAP);
- _Bool result = (hwcap & HWCAP_ATOMICS) != 0;
- if (result) {
- // Some cores in the Exynos 9810 CPU are ARMv8.2 and others are ARMv8.0;
- // only the former support LSE atomics. However, the kernel in the
- // initial Android 8.0 release of Galaxy S9/S9+ devices incorrectly
- // reported the feature as being supported.
- //
- // The kernel appears to have been corrected to mark it unsupported as of
- // the Android 9.0 release on those devices, and this issue has not been
- // observed anywhere else. Thus, this workaround may be removed if
- // compiler-rt ever drops support for Android 8.0.
- if (__isExynos9810())
- result = false;
- }
- __aarch64_have_lse_atomics = result;
- }
|