arm64: add AT_HWCAP2 support for 32-bit compat

Add support for the ELF auxv entry AT_HWCAP2 when running 32-bit
ELF binaries in compat mode.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

2 files changed, 3 insertions, 1 deletions

diff --git a/arch/arm64/include/asm/hwcap.h b/arch/arm64/include/asm/hwcap.h
index 6cddbb0c9f54..9a4cbd60c88e 100644
--- a/arch/arm64/include/asm/hwcap.h
+++ b/arch/arm64/include/asm/hwcap.h
@@ -41,7 +41,8 @@
 
 #ifdef CONFIG_COMPAT
 #define COMPAT_ELF_HWCAP        (compat_elf_hwcap)
-extern unsigned int compat_elf_hwcap;
+#define COMPAT_ELF_HWCAP2       (compat_elf_hwcap2)
+extern unsigned int compat_elf_hwcap, compat_elf_hwcap2;
 #endif
 
 extern unsigned long elf_hwcap;
diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
index c8e9effe52e1..349c49260f09 100644
--- a/arch/arm64/kernel/setup.c
+++ b/arch/arm64/kernel/setup.c
@@ -69,6 +69,7 @@ EXPORT_SYMBOL_GPL(elf_hwcap);
                                  COMPAT_HWCAP_VFPv3|COMPAT_HWCAP_VFPv4|\
                                  COMPAT_HWCAP_NEON|COMPAT_HWCAP_IDIV)
 unsigned int compat_elf_hwcap __read_mostly = COMPAT_ELF_HWCAP_DEFAULT;
+unsigned int compat_elf_hwcap2 __read_mostly;
 #endif
 
 static const char *cpu_name;