+ kfence-kcsan-avoid-passing-g-for-tests.patch added to mm-unstable branch

[Andrew Morton <akpm@linux-foundation.org>]

The patch titled
     Subject: kfence, kcsan: avoid passing -g for tests
has been added to the -mm mm-unstable branch.  Its filename is
     kfence-kcsan-avoid-passing-g-for-tests.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/kfence-kcsan-avoid-passing-g-for-tests.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Marco Elver <elver@google.com>
Subject: kfence, kcsan: avoid passing -g for tests
Date: Thu, 16 Mar 2023 16:51:04 +0100

Nathan reported that when building with GNU as and a version of clang that
defaults to DWARF5:

  $ make -skj"$(nproc)" ARCH=riscv CROSS_COMPILE=riscv64-linux-gnu- \
			LLVM=1 LLVM_IAS=0 O=build \
			mrproper allmodconfig mm/kfence/kfence_test.o
  /tmp/kfence_test-08a0a0.s: Assembler messages:
  /tmp/kfence_test-08a0a0.s:14627: Error: non-constant .uleb128 is not supported
  /tmp/kfence_test-08a0a0.s:14628: Error: non-constant .uleb128 is not supported
  /tmp/kfence_test-08a0a0.s:14632: Error: non-constant .uleb128 is not supported
  /tmp/kfence_test-08a0a0.s:14633: Error: non-constant .uleb128 is not supported
  /tmp/kfence_test-08a0a0.s:14639: Error: non-constant .uleb128 is not supported
  ...

This is because `-g` defaults to the compiler debug info default.  If the
assembler does not support some of the directives used, the above errors
occur.  To fix, remove the explicit passing of `-g`.

All these tests want is that stack traces print valid function names, and
debug info is not required for that.  I currently cannot recall why I
added the explicit `-g`.

Link: https://lkml.kernel.org/r/20230316155104.594662-1-elver@google.com
Signed-off-by: Marco Elver <elver@google.com>
Reported-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---


--- a/kernel/kcsan/Makefile~kfence-kcsan-avoid-passing-g-for-tests
+++ a/kernel/kcsan/Makefile
@@ -16,6 +16,6 @@ obj-y := core.o debugfs.o report.o
 KCSAN_INSTRUMENT_BARRIERS_selftest.o := y
 obj-$(CONFIG_KCSAN_SELFTEST) += selftest.o
 
-CFLAGS_kcsan_test.o := $(CFLAGS_KCSAN) -g -fno-omit-frame-pointer
+CFLAGS_kcsan_test.o := $(CFLAGS_KCSAN) -fno-omit-frame-pointer
 CFLAGS_kcsan_test.o += $(DISABLE_STRUCTLEAK_PLUGIN)
 obj-$(CONFIG_KCSAN_KUNIT_TEST) += kcsan_test.o
--- a/mm/kfence/Makefile~kfence-kcsan-avoid-passing-g-for-tests
+++ a/mm/kfence/Makefile
@@ -2,5 +2,5 @@
 
 obj-y := core.o report.o
 
-CFLAGS_kfence_test.o := -g -fno-omit-frame-pointer -fno-optimize-sibling-calls
+CFLAGS_kfence_test.o := -fno-omit-frame-pointer -fno-optimize-sibling-calls
 obj-$(CONFIG_KFENCE_KUNIT_TEST) += kfence_test.o
_

Patches currently in -mm which might be from elver@google.com are

kasan-powerpc-dont-rename-memintrinsics-if-compiler-adds-prefixes.patch
kfence-kcsan-avoid-passing-g-for-tests.patch