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| author | Konstantin Khorenko <khorenko@virtuozzo.com> | 2026-10-01 18:57:12 +0200 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2026-10-11 15:18:55 -0700 |
| commit | d3e7732253e6552011ccd4b7fc116821c032db76 (patch) | |
| tree | 91af6ec102af1f3b93c211f94e765b04dceff358 /scripts | |
| parent | d41b821621f0c9bc66f8b12ddcb1b6d164d01e28 (diff) | |
| download | linux-next-d3e7732253e6552011ccd4b7fc116821c032db76.tar.gz linux-next-d3e7732253e6552011ccd4b7fc116821c032db76.zip | |
kbuild: move GCOV flags to scripts/Makefile.gcov
* split the CFLAGS_GCOV block out of the top-level Makefile into
scripts/Makefile.gcov
* include it via include-$(CONFIG_GCOV_KERNEL) like neighbour
KASAN/KCOV/UBSAN makefiles do
* keep the include before scripts/Makefile.gcc-plugins: the try-run
must not get -fplugin= options, plugins do not exist on clean builds
CFLAGS_GCOV is no longer defined when CONFIG_GCOV_KERNEL is off:
* its user in scripts/Makefile.lib is guarded by the CONFIG_GCOV_KERNEL
* in i915/xe header an empty value is harmless
The try-run compiler invocations also stop running on builds without
GCOV.
Link: https://lore.kernel.org/20261001-b4-prep-gcov-v1-2-794792e06f24@virtuozzo.com
Signed-off-by: Konstantin Khorenko <khorenko@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Suggested-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nicolas Schier <nsc@kernel.org>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Mikhail Zaslonko <zaslonko@linux.ibm.com>
Diffstat (limited to 'scripts')
| -rw-r--r-- | scripts/Makefile.gcov | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/scripts/Makefile.gcov b/scripts/Makefile.gcov new file mode 100644 index 000000000000..16c5b876440c --- /dev/null +++ b/scripts/Makefile.gcov @@ -0,0 +1,21 @@ +# SPDX-License-Identifier: GPL-2.0-only +CFLAGS_GCOV := -fprofile-arcs -ftest-coverage +ifdef CONFIG_CC_IS_GCC +CFLAGS_GCOV += -fno-tree-loop-im +# Use atomic counter updates to avoid concurrent-access crashes in GCOV. +# Only enable if -fprofile-update=prefer-atomic does not introduce new +# undefined symbols (e.g. libatomic calls that the kernel cannot link). +CFLAGS_GCOV += $(call try-run,\ + echo 'long long x; void f(void){x++;}' | \ + $(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) -w $(CFLAGS_GCOV) \ + -x c - -c -o "$$TMP.base" && \ + echo 'long long x; void f(void){x++;}' | \ + $(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) -w $(CFLAGS_GCOV) \ + -fprofile-update=prefer-atomic \ + -x c - -c -o "$$TMP" && \ + $(NM) "$$TMP.base" | grep ' U ' > "$$TMP.ubase" || true ; \ + $(NM) "$$TMP" | grep ' U ' > "$$TMP.utest" || true ; \ + cmp -s "$$TMP.ubase" "$$TMP.utest",\ + -fprofile-update=prefer-atomic) +endif +export CFLAGS_GCOV |