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authorWill Deacon <will.deacon@arm.com>2018-02-02 17:31:40 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-02-16 20:22:53 +0100
commit48c3538c35780838da19773b615ede148e6af2b0 (patch)
tree0abadfec0aa4b97938751ef6b72641746a4c0270 /arch/arm64/mm
parent6b47a8256a56c261ab008863a548f245fdcc8b11 (diff)
arm64: entry: Apply BP hardening for suspicious interrupts from EL0
Commit 30d88c0e3ace upstream. It is possible to take an IRQ from EL0 following a branch to a kernel address in such a way that the IRQ is prioritised over the instruction abort. Whilst an attacker would need to get the stars to align here, it might be sufficient with enough calibration so perform BP hardening in the rare case that we see a kernel address in the ELR when handling an IRQ from EL0. Reported-by: Dan Hettena <dhettena@nvidia.com> Reviewed-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> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/arm64/mm')
-rw-r--r--arch/arm64/mm/fault.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index 58992467ebb9..5edb706aacb0 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -751,6 +751,12 @@ asmlinkage void __exception do_mem_abort(unsigned long addr, unsigned int esr,
arm64_notify_die("", regs, &info, esr);
}
+asmlinkage void __exception do_el0_irq_bp_hardening(void)
+{
+ /* PC has already been checked in entry.S */
+ arm64_apply_bp_hardening();
+}
+
asmlinkage void __exception do_el0_ia_bp_hardening(unsigned long addr,
unsigned int esr,
struct pt_regs *regs)