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| author | Will Deacon | 2018-01-03 12:17:58 +0100 |
|---|---|---|
| committer | Catalin Marinas | 2018-01-08 19:45:25 +0100 |
| commit | 0f15adbb2861ce6f75ccfc5a92b19eae0ef327d0 (patch) | |
| tree | 918eadd8cc51a5c04e2c9d4e657a4fec8f4b29d4 /arch/arm64/mm/fault.c | |
| parent | arm64: Move post_ttbr_update_workaround to C code (diff) | |
| download | kernel-qcow2-linux-0f15adbb2861ce6f75ccfc5a92b19eae0ef327d0.tar.gz kernel-qcow2-linux-0f15adbb2861ce6f75ccfc5a92b19eae0ef327d0.tar.xz kernel-qcow2-linux-0f15adbb2861ce6f75ccfc5a92b19eae0ef327d0.zip | |
arm64: Add skeleton to harden the branch predictor against aliasing attacks
Aliasing attacks against CPU branch predictors can allow an attacker to
redirect speculative control flow on some CPUs and potentially divulge
information from one context to another.
This patch adds initial skeleton code behind a new Kconfig option to
enable implementation-specific mitigations against these attacks for
CPUs that are affected.
Co-developed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/mm/fault.c')
| -rw-r--r-- | arch/arm64/mm/fault.c | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index 22168cd0dde7..0e671ddf4855 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -708,6 +708,23 @@ asmlinkage void __exception do_mem_abort(unsigned long addr, unsigned int esr, arm64_notify_die("", regs, &info, esr); } +asmlinkage void __exception do_el0_ia_bp_hardening(unsigned long addr, + unsigned int esr, + struct pt_regs *regs) +{ + /* + * We've taken an instruction abort from userspace and not yet + * re-enabled IRQs. If the address is a kernel address, apply + * BP hardening prior to enabling IRQs and pre-emption. + */ + if (addr > TASK_SIZE) + arm64_apply_bp_hardening(); + + local_irq_enable(); + do_mem_abort(addr, esr, regs); +} + + asmlinkage void __exception do_sp_pc_abort(unsigned long addr, unsigned int esr, struct pt_regs *regs) |