Re: [PATCH 00/12] error handling and pciehp maintenance

From: Will Deacon
Date: Tue Oct 09 2018 - 12:03:31 EST

Hi Bjorn,

On Fri, Oct 05, 2018 at 12:31:45PM -0500, Bjorn Helgaas wrote:
> [+cc arm64 folks, LKML: This conversation is about this patch:
> which fixes some PCIe AER error injection bugs, but also makes the error
> injector dependent on DYNAMIC_FTRACE_WITH_REGS, which not all arches
> support. Note that this question is only about the error *injection*
> module used for testing. It doesn't affect AER support itself.]
> On Thu, Oct 04, 2018 at 04:11:37PM -0600, Keith Busch wrote:
> > In case this went unnoticed, patch 2's aer_inject using ftrace hooks
> > to pci config accessors is really cool and fixes several kernel crashes
> > I encountered, but it may not work on every architecture. I'm not sure
> > how widely aer_inject is used, so maybe there are no concerns with the
> > DYNAMIC_FTRACE_WITH_REGS dependency, but I just want to reemphasize that
> > dependency in case there are valid objections.
> Oh, indeed, I hadn't noticed this arch dependency. AFAICT, the new
> DYNAMIC_FTRACE_WITH_REGS dependency means aer_inject will work only
> on these arches:
> arm # if (!XIP_KERNEL) && !CPU_ENDIAN_BE32 && MMU
> powerpc # if PPC64 && CPU_LITTLE_ENDIAN
> riscv # ARCH_RV64I only
> s390
> x86
> Notably missing is arm64, which has DYNAMIC_FTRACE but not

Thanks for the heads-up here. This feature is currently in development for

but the latest review comments suggest that it's a fair way from ready yet,
so I wouldn't hold your breath.