| #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; |
| } |
