This is a note to let you know that I've just added the patch titled
powerpc: Don't select ARCH_WANTS_NO_INSTR
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
powerpc-don-t-select-arch_wants_no_instr.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 576df3005b36595b5ded85fd8900b6ff26b89adf
Author: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Date: Thu Feb 2 21:27:35 2023 +1100
powerpc: Don't select ARCH_WANTS_NO_INSTR
[ Upstream commit e33416fca8a2313b8650bd5807aaf34354d39a4c ]
Commit 41b7a347bf14 ("powerpc: Book3S 64-bit outline-only KASAN
support") added a select of ARCH_WANTS_NO_INSTR, because it also added
some uses of noinstr. However noinstr is always defined, regardless of
ARCH_WANTS_NO_INSTR, so there's no need to select it just for that.
As PeterZ says [1]:
Note that by selecting ARCH_WANTS_NO_INSTR you effectively state to
abide by its rules.
As of now the powerpc code does not abide by those rules, and trips some
new warnings added by Peter in linux-next.
So until the code can be fixed to avoid those warnings, disable
ARCH_WANTS_NO_INSTR.
Note that ARCH_WANTS_NO_INSTR is also used to gate building KCOV and
parts of KCSAN. However none of the noinstr annotations in powerpc were
added for KCOV or KCSAN, instead instrumentation is blocked at the file
level using KCOV_INSTRUMENT_foo.o := n.
[1]: https://lore.kernel.org/linuxppc-dev/Y9t6yoafrO5YqVgM@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Reported-by: Sachin Sant <sachinp@xxxxxxxxxxxxx>
Suggested-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 2ca5418457ed2..2b1141645d9e1 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -161,7 +161,6 @@ config PPC
select ARCH_WANT_IRQS_OFF_ACTIVATE_MM
select ARCH_WANT_LD_ORPHAN_WARN
select ARCH_WANTS_MODULES_DATA_IN_VMALLOC if PPC_BOOK3S_32 || PPC_8xx
- select ARCH_WANTS_NO_INSTR
select ARCH_WEAK_RELEASE_ACQUIRE
select BINFMT_ELF
select BUILDTIME_TABLE_SORT
