From: Yury Norov <[email protected]> Make sure we have AArch32 state available for running COMPAT binaries and also for switching the personality to PER_LINUX32.
Signed-off-by: Yury Norov <[email protected]> [ Added cap bit, checks for HWCAP, personality ] Signed-off-by: Suzuki K Poulose <[email protected]> Tested-by: Yury Norov <[email protected]> --- arch/arm64/include/asm/elf.h | 3 ++- arch/arm64/kernel/cpufeature.c | 7 +++++-- arch/arm64/kernel/sys.c | 4 ++++ 3 files changed, 11 insertions(+), 3 deletions(-) diff --git a/arch/arm64/include/asm/elf.h b/arch/arm64/include/asm/elf.h index 24ed037..7a09c48 100644 --- a/arch/arm64/include/asm/elf.h +++ b/arch/arm64/include/asm/elf.h @@ -177,7 +177,8 @@ typedef compat_elf_greg_t compat_elf_gregset_t[COMPAT_ELF_NGREG]; /* AArch32 EABI. */ #define EF_ARM_EABI_MASK 0xff000000 -#define compat_elf_check_arch(x) (((x)->e_machine == EM_ARM) && \ +#define compat_elf_check_arch(x) (system_supports_32bit_el0() && \ + ((x)->e_machine == EM_ARM) && \ ((x)->e_flags & EF_ARM_EABI_MASK)) #define compat_start_thread compat_start_thread diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 739314b..c31be96 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -982,7 +982,8 @@ void verify_local_cpu_capabilities(void) verify_local_cpu_features(arm64_features); verify_local_elf_hwcaps(arm64_elf_hwcaps); - verify_local_elf_hwcaps(compat_elf_hwcaps); + if (system_supports_32bit_el0()) + verify_local_elf_hwcaps(compat_elf_hwcaps); } static void __init setup_feature_capabilities(void) @@ -999,7 +1000,9 @@ void __init setup_cpu_features(void) /* Set the CPU feature capabilies */ setup_feature_capabilities(); setup_elf_hwcaps(arm64_elf_hwcaps); - setup_elf_hwcaps(compat_elf_hwcaps); + + if (system_supports_32bit_el0()) + setup_elf_hwcaps(compat_elf_hwcaps); /* Advertise that we have computed the system capabilities */ set_sys_caps_initialised(); diff --git a/arch/arm64/kernel/sys.c b/arch/arm64/kernel/sys.c index 817d860..26fe8ea 100644 --- a/arch/arm64/kernel/sys.c +++ b/arch/arm64/kernel/sys.c @@ -25,6 +25,7 @@ #include <linux/sched.h> #include <linux/slab.h> #include <linux/syscalls.h> +#include <asm/cpufeature.h> asmlinkage long sys_mmap(unsigned long addr, unsigned long len, unsigned long prot, unsigned long flags, @@ -38,6 +39,9 @@ asmlinkage long sys_mmap(unsigned long addr, unsigned long len, SYSCALL_DEFINE1(arm64_personality, unsigned int, personality) { + if (personality(personality) == PER_LINUX32 && + !system_supports_32bit_el0()) + return -EINVAL; return sys_personality(personality); } -- 1.7.9.5
