[PATCH 0/1] MR7123: ntdll: Detect kernel support before using ARM64 ID regs.

[PATCH 1/1] ntdll: Detect kernel support before using ARM64 ID regs.

[Billy Laws]

From: Billy Laws

---
 configure.ac             |  1 +
 dlls/ntdll/unix/system.c | 11 +++++++++++
 2 files changed, 12 insertions(+)

diff --git a/configure.ac b/configure.ac
index 6596f653fb1..97746ef5565 100644
--- a/configure.ac
+++ b/configure.ac
@@ -370,6 +370,7 @@ AC_CHECK_HEADERS(\
    OpenCL/opencl.h \
    arpa/inet.h \
    arpa/nameser.h \
+	asm/hwcap.h \
    asm/termbits.h \
    asm/types.h \
    asm/user.h \
diff --git a/dlls/ntdll/unix/system.c b/dlls/ntdll/unix/system.c
index 13f37ee8a9a..2e1ee850e3d 100644
--- a/dlls/ntdll/unix/system.c
+++ b/dlls/ntdll/unix/system.c
@@ -54,6 +54,12 @@
 #ifdef HAVE_SYS_RESOURCE_H
 # include <sys/resource.h>
 #endif
+#ifdef HAVE_ASM_HWCAP_H
+# include <asm/hwcap.h>
+#endif
+#ifdef HAVE_SYS_AUXV_H
+# include <sys/auxv.h>
+#endif
 #ifdef __APPLE__
 # include <CoreFoundation/CoreFoundation.h>
 # include <IOKit/IOKitLib.h>
@@ -1709,6 +1715,11 @@ static DWORD get_core_id_regs_arm64( struct smbios_wine_id_reg_value_arm64 *regs
         regs[regidx++] = (struct smbios_wine_id_reg_value_arm64){ 0x4000, value };
     }

+    if (!(getauxval(AT_HWCAP) & HWCAP_CPUID)) {
+        FIXME("Skipping ID register population as kernel is missing emulation support.\n");
+        return regidx;
+    }
+
 #define STR(a) #a
 #define READ_ID_REG(reg_id) \
     /* mrs x0, #reg_id */ \