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[195.23.151.163]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-4606f2637ccsm4885808f8f.6.2026.06.12.04.37.12 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 12 Jun 2026 04:37:14 -0700 (PDT) Sender: Julian Braha Message-ID: <2e528372-aba4-4621-a9a3-7ce23571ef37@gmail.com> Date: Fri, 12 Jun 2026 12:37:11 +0100 Precedence: bulk X-Mailing-List: llvm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [RFC PATCH v2 01/14] kcov: add per-task dataflow tracking for function arguments/return values To: Yunseong Kim , Ingo Molnar , Peter Zijlstra , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Valentin Schneider , K Prateek Nayak , Andrey Konovalov , Alexander Potapenko , Dmitry Vyukov , Andrew Morton , Miguel Ojeda , Boqun Feng , Gary Guo , =?UTF-8?Q?Bj=C3=B6rn_Roy_Baron?= , Benno Lossin , Andreas Hindborg , Alice Ryhl , Trevor Gross , Danilo Krummrich , Nathan Chancellor , Nicolas Schier , Nick Desaulniers , Bill Wendling , Justin Stitt , Kees Cook , David Hildenbrand , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Shuah Khan , Jonathan Corbet , Shuah Khan Cc: linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com, rust-for-linux@vger.kernel.org, linux-kbuild@vger.kernel.org, llvm@lists.linux.dev, linux-mm@kvack.org, linux-kselftest@vger.kernel.org, workflows@vger.kernel.org, linux-doc@vger.kernel.org, Yeoreum Yun References: <20260611-b4-kcov-dataflow-v2-v2-0-0a261da3987c@est.tech> <20260611-b4-kcov-dataflow-v2-v2-1-0a261da3987c@est.tech> Content-Language: en-US From: Julian Braha In-Reply-To: <20260611-b4-kcov-dataflow-v2-v2-1-0a261da3987c@est.tech> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 6/11/26 17:21, Yunseong Kim wrote: > +config KCOV_DATAFLOW_RET > + bool "Enable KCOV dataflow: return value capture" > + depends on KCOV > + depends on DEBUG_INFO > + depends on $(cc-option,-fsanitize-coverage=trace-ret) > + help > + Captures function return values via /sys/kernel/debug/kcov_dataflow. > + Struct pointer returns are auto-expanded using compiler DebugInfo > + metadata, recording individual field values at runtime. > + Enable per-module with: KCOV_DATAFLOW_file.o := y in the Makefile. > + Requires clang with -fsanitize-coverage=trace-ret support. > + > +config KCOV_DATAFLOW_NO_INLINE > + bool "Disable inlining for dataflow-instrumented files" > + default n In Kconfig, when you don't specify any default explicitly, it's implicitly 'default n'. I think either style (implicit or explicit) is fine and both are used throughout the kernel, but is there any reason to make it explicit only for KCOV_DATAFLOW_NO_INLINE, and implicit for the others? - Julian Braha