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authorMasahiro Yamada2019-02-21 13:13:38 +0900
committerMasahiro Yamada2019-02-27 21:43:20 +0900
commitb303c6df80c9f8f13785aa83a0471fca7e38b24d (patch)
treee5115e2524486b8633a4d024e9a1d2761f3c181f /kernel/trace
parentbd55f96fa9fc29702ec30d75a4290bdadb00209d (diff)
kbuild: compute false-positive -Wmaybe-uninitialized cases in Kconfig
Since -Wmaybe-uninitialized was introduced by GCC 4.7, we have patched various false positives: - commit e74fc973b6e5 ("Turn off -Wmaybe-uninitialized when building with -Os") turned off this option for -Os. - commit 815eb71e7149 ("Kbuild: disable 'maybe-uninitialized' warning for CONFIG_PROFILE_ALL_BRANCHES") turned off this option for CONFIG_PROFILE_ALL_BRANCHES - commit a76bcf557ef4 ("Kbuild: enable -Wmaybe-uninitialized warning for "make W=1"") turned off this option for GCC < 4.9 Arnd provided more explanation in https://lkml.org/lkml/2017/3/14/903 I think this looks better by shifting the logic from Makefile to Kconfig. Link: https://github.com/ClangBuiltLinux/linux/issues/350 Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by: Nathan Chancellor <natechancellor@gmail.com> Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Diffstat (limited to 'kernel/trace')
-rw-r--r--kernel/trace/Kconfig1
1 files changed, 1 insertions, 0 deletions
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index fa8b1fe824f3..8bd1d6d001d7 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -370,6 +370,7 @@ config PROFILE_ANNOTATED_BRANCHES
config PROFILE_ALL_BRANCHES
bool "Profile all if conditionals" if !FORTIFY_SOURCE
select TRACE_BRANCH_PROFILING
+ imply CC_DISABLE_WARN_MAYBE_UNINITIALIZED # avoid false positives
help
This tracer profiles all branch conditions. Every if ()
taken in the kernel is recorded whether it hit or miss.