From: Peter Zijlstra <peterz@infradead.org>
To: Yunseong Kim <yunseong.kim@est.tech>
Cc: "Ingo Molnar" <mingo@redhat.com>,
"Juri Lelli" <juri.lelli@redhat.com>,
"Vincent Guittot" <vincent.guittot@linaro.org>,
"Dietmar Eggemann" <dietmar.eggemann@arm.com>,
"Steven Rostedt" <rostedt@goodmis.org>,
"Ben Segall" <bsegall@google.com>, "Mel Gorman" <mgorman@suse.de>,
"Valentin Schneider" <vschneid@redhat.com>,
"K Prateek Nayak" <kprateek.nayak@amd.com>,
"Dmitry Vyukov" <dvyukov@google.com>,
"Andrey Konovalov" <andreyknvl@gmail.com>,
"Andrew Morton" <akpm@linux-foundation.org>,
"Nathan Chancellor" <nathan@kernel.org>,
"Nick Desaulniers" <nick.desaulniers+lkml@gmail.com>,
"Bill Wendling" <morbo@google.com>,
"Justin Stitt" <justinstitt@google.com>,
"Nicolas Schier" <nsc@kernel.org>,
"Miguel Ojeda" <ojeda@kernel.org>,
"Boqun Feng" <boqun@kernel.org>, "Gary Guo" <gary@garyguo.net>,
"Björn Roy Baron" <bjorn3_gh@protonmail.com>,
"Benno Lossin" <lossin@kernel.org>,
"Andreas Hindborg" <a.hindborg@kernel.org>,
"Alice Ryhl" <aliceryhl@google.com>,
"Trevor Gross" <tmgross@umich.edu>,
"Danilo Krummrich" <dakr@kernel.org>,
"Jonathan Corbet" <corbet@lwn.net>,
"Shuah Khan" <skhan@linuxfoundation.org>,
linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com,
llvm@lists.linux.dev, linux-kbuild@vger.kernel.org,
rust-for-linux@vger.kernel.org, workflows@vger.kernel.org,
linux-doc@vger.kernel.org, "Yunseong Kim" <ysk@kzalloc.com>
Subject: Re: [RFC PATCH v2 2/6] kcov: add build system support for dataflow instrumentation
Date: Thu, 4 Jun 2026 10:45:19 +0200 [thread overview]
Message-ID: <20260604084519.GA3126523@noisy.programming.kicks-ass.net> (raw)
In-Reply-To: <20260603-kcov-dataflow-next-20260603-v2-2-fee0939de2c4@est.tech>
On Wed, Jun 03, 2026 at 07:43:29PM +0200, Yunseong Kim wrote:
> Add CFLAGS_KCOV_DATAFLOW and RUSTFLAGS_KCOV_DATAFLOW exports to
> scripts/Makefile.kcov, containing:
> -fsanitize-coverage=dataflow-args,dataflow-ret -g
> (with optional -fno-inline via CONFIG_KCOV_DATAFLOW_NO_INLINE)
>
> scripts/Makefile.lib applies these flags when a module's Makefile sets:
> KCOV_DATAFLOW_file.o := y (per-file)
> KCOV_DATAFLOW := y (per-directory)
>
> Also supports CONFIG_KCOV_DATAFLOW_INSTRUMENT_ALL for global enablement.
> The flags are only applied to kernel objects (same guard as basic KCOV).
>
> Signed-off-by: Yunseong Kim <yunseong.kim@est.tech>
> ---
> scripts/Makefile.kcov | 6 ++++++
> scripts/Makefile.lib | 7 +++++++
> 2 files changed, 13 insertions(+)
>
> diff --git a/scripts/Makefile.kcov b/scripts/Makefile.kcov
> index 78305a84ba9d..101173fe194b 100644
> --- a/scripts/Makefile.kcov
> +++ b/scripts/Makefile.kcov
> @@ -2,10 +2,16 @@
> kcov-flags-y += -fsanitize-coverage=trace-pc
> kcov-flags-$(CONFIG_KCOV_ENABLE_COMPARISONS) += -fsanitize-coverage=trace-cmp
>
> +# KCOV dataflow: trace function args and return values
> +kcov-dataflow-flags-y := -fsanitize-coverage=dataflow-args,dataflow-ret -g
> +kcov-dataflow-flags-$(CONFIG_KCOV_DATAFLOW_NO_INLINE) += -fno-inline
https://clang.llvm.org/docs/ClangCommandLineReference.html
Has no mention of -fno-inline, furthermore, what are the exact
semantics? Does it inhibit __always_inline?
next prev parent reply other threads:[~2026-06-04 8:45 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-06-03 17:43 [RFC PATCH v2 0/6] kcov: per-task dataflow extraction at kernel function boundaries Yunseong Kim
2026-06-03 17:43 ` [RFC PATCH v2 1/6] kcov: add per-task dataflow tracking for function arguments/return values Yunseong Kim
2026-06-04 8:41 ` Peter Zijlstra
2026-06-03 17:43 ` [RFC PATCH v2 2/6] kcov: add build system support for dataflow instrumentation Yunseong Kim
2026-06-04 8:45 ` Peter Zijlstra [this message]
2026-06-04 21:48 ` Nathan Chancellor
2026-06-03 17:43 ` [RFC PATCH v2 3/6] kcov: add CONFIG_KCOV_DATAFLOW_INSTRUMENT_ALL and NO_INLINE Yunseong Kim
2026-06-04 8:46 ` Peter Zijlstra
2026-06-03 17:43 ` [RFC PATCH v2 4/6] tools/kcov-dataflow: add userspace consumer and test modules Yunseong Kim
2026-06-03 17:43 ` [RFC PATCH v2 5/6] kcov: add interrupt context guard to kcov_df_write() Yunseong Kim
2026-06-04 8:48 ` Peter Zijlstra
2026-06-03 17:43 ` [RFC PATCH v2 6/6] kcov: add recursion guard and documentation for kcov-dataflow Yunseong Kim
2026-06-04 8:52 ` Peter Zijlstra
2026-06-04 8:40 ` [RFC PATCH v2 0/6] kcov: per-task dataflow extraction at kernel function boundaries Peter Zijlstra
2026-06-04 9:29 ` Yunseong Kim
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