linux/arch/arm64
Will Deacon 1059c6bf85 arm64: debug: don't re-enable debug exceptions on return from el1_dbg
When returning from a debug exception taken from EL1, we unmask debug
exceptions after handling the exception. This is crucial for debug
exceptions taken from EL0, so that any kernel work on the ret_to_user
path can be debugged by kgdb.

However, when returning back to EL1 the only thing left to do is to
restore the original register state before the exception return. If
single-step has been enabled by the debug exception handler, we will
get stuck in an infinite debug exception loop, since we will take the
step exception as soon as we unmask debug exceptions.

This patch avoids unmasking debug exceptions on the debug exception
return path when the exception was taken from EL1.

Fixes: 2a2830703a (arm64: debug: avoid accessing mdscr_el1 on fault paths where possible)
Cc: <stable@vger.kernel.org> #3.16+
Reported-by: David Long <dave.long@linaro.org>
Reported-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-09-23 15:49:34 +01:00
..
boot dts: Add bindings for APM X-Gene SoC ethernet driver 2014-08-11 11:50:33 -07:00
configs arm64: configs: Enable X-Gene SATA and ethernet in defconfig 2014-08-19 19:26:09 +01:00
crypto arm64/crypto: remove redundant update of data 2014-08-26 11:42:22 +01:00
include Revert "arm64: dmi: Add SMBIOS/DMI support" 2014-09-22 18:12:37 +01:00
kernel arm64: debug: don't re-enable debug exceptions on return from el1_dbg 2014-09-23 15:49:34 +01:00
kvm arm/arm64: KVM: Complete WFI/WFE instructions 2014-08-29 11:53:53 +02:00
lib arm64: lib: Implement optimized string length routines 2014-05-23 15:17:12 +01:00
mm arm64: Implement set_arch_dma_coherent_ops() to replace bus notifiers 2014-09-22 11:48:31 +01:00
net net: bpf: arm64: fix module memory leak when JIT image build fails 2014-09-12 16:33:14 +01:00
xen arm: xen: implement multicall hypercall support. 2014-04-24 13:09:46 +01:00
Kconfig Revert "arm64: dmi: Add SMBIOS/DMI support" 2014-09-22 18:12:37 +01:00
Kconfig.debug arm64: Add CONFIG_DEBUG_SET_MODULE_RONX support 2014-09-08 14:39:18 +01:00
Makefile arm64: eBPF JIT compiler 2014-09-08 14:39:21 +01:00