[PATCH v2 0/8] arm64: stacktrace: cleanups and improvements

Mark Rutland
2022-08-05T12:46:54Z

Hi Marc,

This series is a set of improvements for the recently merged stacktrace
rework queued in the kvmarm next branch, along the lines of my prior
suggestions. I'm hoping that it would be possible to queue this for
-rc1.

Largely, the series decouples portions of the unwind code, making some
structural changes that remove the need for coupling (e.g. removing the
need for the stack type enumeration, and factoring out callbacks). This
should make it easier to make some further changes I have spoken about
previously (e.g. adding some metadata to the stack dump output), and I
have some patches building atop this which I intend to send out once
this is merged.

The only (intended) functional change from this series is improved
boundary detection, where overlapping frame records will now be caught
and rejected.

I've tested this natively (with the ftrace tests, LKDTM, and
/proc/self/stack), which seems happy.

I've also tested the NVHE and PKVM unwinders by hacking a BUG() into the
hyp code shortly after the KVM hyp code is initialized, and in both
cases the output is unchanged.

Since v1 [1]:
* Fix build warning with CONFIG_SDEI_INTERFACE=y && W=1
* Fix typos
* Fix whitespace errors
* Apply tags from Kalesh Singh and Mark Brown

[1] https://lore.kernel.org/r/20220801121209.2479449-1-mark.rutland@arm.com

Thanks,
Mark.

Mark Rutland (8):
arm64: stacktrace: simplify unwind_next_common()
arm64: stacktrace: rename unwind_next_common() ->
unwind_next_frame_record()
arm64: stacktrace: move SDEI stack helpers to stacktrace code
arm64: stacktrace: add stackinfo_on_stack() helper
arm64: stacktrace: rework stack boundary discovery
arm64: stacktrace: remove stack type from fp translator
arm64: stacktrace: track all stack boundaries explicitly
arm64: stacktrace: track hyp stacks in unwinder's address space

arch/arm64/include/asm/processor.h | 2 +-
arch/arm64/include/asm/sdei.h | 17 --
arch/arm64/include/asm/stacktrace.h | 71 +++++--
arch/arm64/include/asm/stacktrace/common.h | 211 +++++++++------------
arch/arm64/kernel/ptrace.c | 2 +-
arch/arm64/kernel/sdei.c | 32 ----
arch/arm64/kernel/stacktrace.c | 66 ++++---
arch/arm64/kvm/hyp/nvhe/stacktrace.c | 40 ++--
arch/arm64/kvm/stacktrace.c | 135 +++++++------
9 files changed, 288 insertions(+), 288 deletions(-)

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2.30.2