mirror_ubuntu-kernels/arch/arm64
Mark Rutland 6f6cfa5867 arm64: mm: use die_kernel_fault() in do_mem_abort()
If we take an unhandled fault from EL1, either:

a) The xFSC handler calls die_kernel_fault() directly. In this case,
   die_kernel_fault() calls:

   pr_alert(..., msg, addr);
   mem_abort_decode(esr);
   show_pte(addr);
   die();
   bust_spinlocks(0);
   do_exit(SIGKILL);

b) The xFSC handler returns to do_mem_abort(), indicating failure. In
   this case, do_mem_abort() calls:

   pr_alert(..., addr);
   mem_abort_decode(esr);
   show_pte(addr);
   arm64_notify_die() {
     die();
   }

This inconstency is unfortunatem, and in theory in case (b) registered
notifiers can prevent us from terminating the faulting thread by
returning NOTIFY_STOP, whereupon we'll end up returning from the fault,
replaying, and almost certainly get stuck in a livelock spewing errors
into dmesg. We don't expect notifers to fix things up, since we dump
state to dmesg before invoking them, so it would be more sensible to
consistently terminate the thread in this case.

This patch has do_mem_abort() call die_kernel_fault() for unhandled
faults taken from EL1. Where we would previously have logged a messafe
of the form:

| Unhandled fault at ${ADDR}

... we will now log a message of the form:

| Unable to handle kernel ${FAULT_NAME} at virtual address ${ADDR}

... and we will consistently terminate the thread from which the fault
was taken.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will@kernel.org>
Tested-by: Andrey Konovalov <andreyknvl@gmail.com>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20211207183226.834557-2-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-12-13 18:47:09 +00:00
..
boot arm64: dts: exynos: drop samsung,ufs-shareability-reg-offset in ExynosAutov9 2021-11-25 14:46:00 +01:00
configs ARM: defconfig updates for 5.16 2021-11-03 17:07:02 -07:00
crypto crypto: arm64/aes-ccm - avoid by-ref argument for ce_aes_ccm_auth_data 2021-09-17 11:05:11 +08:00
hyperv arm64: hyperv: Initialize hypervisor on boot 2021-08-04 16:54:36 +00:00
include arm64: uaccess: avoid blocking within critical sections 2021-11-24 09:16:26 +00:00
kernel arm64: ftrace: use HAVE_FUNCTION_GRAPH_RET_ADDR_PTR 2021-11-16 09:47:54 +00:00
kvm KVM: arm64: Cap KVM_CAP_NR_VCPUS by kvm_arm_default_max_vcpus() 2021-11-18 02:12:14 -05:00
lib Kbuild updates for v5.16 2021-11-08 09:15:45 -08:00
mm arm64: mm: use die_kernel_fault() in do_mem_abort() 2021-12-13 18:47:09 +00:00
net arm64 updates for 5.16 2021-11-01 16:33:53 -07:00
tools Merge branch 'for-next/trbe-errata' into for-next/core 2021-10-29 12:25:33 +01:00
xen xen: allow pv-only hypercalls only with CONFIG_XEN_PV 2021-11-02 08:11:01 -05:00
Kbuild kbuild: use more subdir- for visiting subdirectories while cleaning 2021-10-24 13:49:46 +09:00
Kconfig Merge branch 'akpm' (patches from Andrew) 2021-11-06 14:08:17 -07:00
Kconfig.debug
Kconfig.platforms ARM: SoC drivers for 5.16 2021-11-03 17:00:52 -07:00
Makefile kbuild: use more subdir- for visiting subdirectories while cleaning 2021-10-24 13:49:46 +09:00