arm64be fails with -fsanitize=shadow-call-stack

[arndb]

Bugzilla Link	46076
Resolution	FIXED
Resolved on	Jun 24, 2020 09:23
Version	trunk
OS	Linux
Blocks	#4440 #44654
CC	@MaskRay,@nickdesaulniers,@pcc,@zygoloid,@samitolvanen,@tstellar
Fixed by commit(s)	a2a3e9f b9c6871 1a25347 f9da0a7

Extended Description

Building the Linux kernel with the newly added support for -fsanitize=shadow-call-stack fails on big-endian platforms with:

clang: error: unsupported option '-fsanitize=shadow-call-stack' for target 'aarch64_be-unknown-linux'

I have submitted a workaround for the kernel, but this is likely a bug in clang and there may be no technical reason to prevent the combination.

[arndb]

assigned to @tstellar

[MaskRay]

https://reviews.llvm.org/D80647

[MaskRay]

a2a3e9f

Will ask tstellar to cherry pick to release/10.x

[MaskRay]

Apologies that I found the wrong place in a2a3e9f

b9c6871 is the proper fix. Both are needed because they touch the same lines.

[MaskRay]

Reopen for release-10.0.1

Needs to merge a2a3e9f and b9c6871

to avoid Linux kernel patch like https://lore.kernel.org/linux-arm-kernel/20200527134016.753354-1-arnd@arndb.de/ [PATCH] arm64: disable -fsanitize=shadow-call-stack for big-endian

[tstellar]

Tim,

What do you think about merging these?

https://reviews.llvm.org/rGa2a3e9f0a6e91103a0d1fa73086dbdf109c48f69
https://reviews.llvm.org/rGb9c6871a9570975827dc0bbeb39131c99c8daf8e

[TNorthover]

Yep, this one looks fine.

[tstellar]

Merged: f9da0a7