I reviewed the changes briefly. They look good. I will take a more detailed look this week. Thanks for doing this! Once this is part of v5.16-rc2, I will send out version 11 on top of that with the rest of the patches in my series. Madhavan On 11/12/21 11:44 AM, Mark Rutland wrote: > On Fri, Oct 22, 2021 at 07:02:43PM +0100, Mark Rutland wrote: >> On Thu, Oct 14, 2021 at 09:58:37PM -0500, madvenka@xxxxxxxxxxxxxxxxxxx wrote: >>> From: "Madhavan T. Venkataraman" <madvenka@xxxxxxxxxxxxxxxxxxx> >>> >>> Currently, there are multiple functions in ARM64 code that walk the >>> stack using start_backtrace() and unwind_frame() or start_backtrace() >>> and walk_stackframe(). They should all be converted to use >>> arch_stack_walk(). This makes maintenance easier. >>> >>> To do that, arch_stack_walk() must always be defined. arch_stack_walk() >>> is within #ifdef CONFIG_STACKTRACE. So, select STACKTRACE in >>> arch/arm64/Kconfig. >> >> I'd prefer if we could decouple ARCH_STACKWALK from STACKTRACE, so that >> we don't have to expose /proc/*/stack unconditionally, which Peter >> Zijlstra has a patch for: >> >> https://lore.kernel.org/lkml/20211022152104.356586621@xxxxxxxxxxxxx/ >> >> ... but regardless the rest of the series looks pretty good, so I'll go >> review that, and we can figure out how to queue the bits and pieces in >> the right order. > > FWIW, it looks like the direction of travel there is not go and unify > the various arch unwinders, but I would like to not depend on > STACKTRACE. Regardless, the initial arch_stack_walk() cleanup patches > all look good, so I reckon we should try to get those out of the way and > queue those for arm64 soon even if we need some more back-and-forth over > the later part of the series. > > With that in mind, I've picked up Peter's patch decoupling > ARCH_STACKWALK from STACKTRACE, and rebased the initial patches from > this series atop. Since there's some subtltety in a few cases (and this > was easy to miss while reviewing), I've expanded the commit messages > with additional rationale as to why each transformation is safe. > I've pushed that to: > > https://git.kernel.org/pub/scm/linux/kernel/git/mark/linux.git/log/?h=arm64/stacktrace/arch-stack-walk > > There's a dependency on: > > https://lore.kernel.org/r/20211029162245.39761-1-mark.rutland@xxxxxxx > > ... which was queued for v5.16-rc1, but got dropped due to a conflict, > and I'm expecting it to be re-queued as a fix for v5.16-rc2 shortly > after v5.16-rc1 is tagged. Hopefully that means we have a table base by > v5.16-rc2. > > I'll send the preparatory series as I've prepared it shortly after > v5.16-rc1 so that people can shout if I've messed something up. > > Hopefully it's easy enough to use that as a base for the more involved > rework later in this series. > > Thanks, > Mark. > >> Thanks, >> Mark. >> >>> >>> Signed-off-by: Madhavan T. Venkataraman <madvenka@xxxxxxxxxxxxxxxxxxx> >>> --- >>> arch/arm64/Kconfig | 1 + >>> 1 file changed, 1 insertion(+) >>> >>> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig >>> index fdcd54d39c1e..bfb0ce60d820 100644 >>> --- a/arch/arm64/Kconfig >>> +++ b/arch/arm64/Kconfig >>> @@ -35,6 +35,7 @@ config ARM64 >>> select ARCH_HAS_SET_DIRECT_MAP >>> select ARCH_HAS_SET_MEMORY >>> select ARCH_STACKWALK >>> + select STACKTRACE >>> select ARCH_HAS_STRICT_KERNEL_RWX >>> select ARCH_HAS_STRICT_MODULE_RWX >>> select ARCH_HAS_SYNC_DMA_FOR_DEVICE >>> -- >>> 2.25.1 >>>
