From nobody Fri Apr 3 20:54:50 2026 Received: from stravinsky.debian.org (stravinsky.debian.org [82.195.75.108]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5C99138910A for ; Mon, 23 Mar 2026 11:12:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=82.195.75.108 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774264357; cv=none; b=QCpigFWr+wYcMGkeQgxiuulJ+hPnH+BRLnaP8gp9PmzSGJ0kSluMhYvm7v+MU1Bxp7fm4O8qRS7fgdS71w3GdALlEhHKqfU5SXAQXylEQMmicQUY5j8eKO8SZIP2TQ7n8lUUxXBkMGc2E2l6yc/vY24zw43t0BZKrJ7Antmx3hM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774264357; c=relaxed/simple; bh=YVhCrOyKP8U5J2m4qj3vibyEe1/805eqdpLycoz/rnY=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:To:Cc; b=BLwHhLvuquKLlZQA8/grMKyHJ4+6HsfYZvLTTXVFuuYzeXzjALaqcvyT2yQL0F+LTwV1iqguRsVpwtdL9yLNzKh7lhnbAlMqm3qvjoakGv7X86Z6d8GKoWSs88+R3If58SMtahjli637YqP9/GdTNYPBJEWpluE/I46NcAQjnYw= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=debian.org; spf=none smtp.mailfrom=debian.org; dkim=pass (2048-bit key) header.d=debian.org header.i=@debian.org header.b=YOljAU/Z; arc=none smtp.client-ip=82.195.75.108 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=debian.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=debian.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=debian.org header.i=@debian.org header.b="YOljAU/Z" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=debian.org; s=smtpauto.stravinsky; h=X-Debian-User:Cc:To:Message-Id: Content-Transfer-Encoding:Content-Type:MIME-Version:Subject:Date:From: Reply-To:Content-ID:Content-Description:In-Reply-To:References; bh=ZFeIWrGHjRim8Xv7+YHIDchaEbhGi1ADAz48lTo4krk=; b=YOljAU/ZElMmKiNRgIrKyAPmmw R5twgqXYjYtfkQPRJyiAwlOynY1scOFP0tFCRAhIIB2erGUffmOitwbW3m/9Wr2VcDvFDYq8+SkS0 f2zwCl6Kf/R1bUnznWchb9AE5Vppx7lVsfrXY2ABJRZmsFXabgddgZeTyOYYzIsILmRGbWby1noHb fqEUYMDSxto8EZydP2ty1FJyuDYYNPmCWSknVoCr/E8SNKZm8gBA/WsGstZrz372Umy0PzJ5UTnQH XsDf1BlU0xRFl23Qrm2WCso7gBNiJq71HOd705G7jnE/GI5kRjzr6CiiqwgjC+0vVkiNVXGQMm/Kb wTyLJqNA==; Received: from authenticated user by stravinsky.debian.org with esmtpsa (TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim 4.94.2) (envelope-from ) id 1w4dCv-007UQb-An; Mon, 23 Mar 2026 11:12:28 +0000 From: Breno Leitao Date: Mon, 23 Mar 2026 04:12:13 -0700 Subject: [PATCH] mm: kmemleak: add CONFIG_DEBUG_KMEMLEAK_VERBOSE build option Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20260323-kmemleak_report-v1-1-ba2cdd9c11b9@debian.org> X-B4-Tracking: v=1; b=H4sIAA0gwWkC/yXMywrCMBAF0F8Z7rqBNAHR/IqIxHjVsfbBpIpQ+ u+iLs/mLKg0ZUWSBcaXVh0HJGkbQbnl4UqnZyRB8GHjY4iu69k/mLujcRptdnmXWx9JX7YFjWA yXvT9G/eHv+vzdGeZvw3W9QOanUyUcwAAAA== X-Change-ID: 20260323-kmemleak_report-a9a103ee0c8c To: Andrew Morton , Catalin Marinas , David Hildenbrand Cc: Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , linux-mm@kvack.org, linux-kernel@vger.kernel.org, kernel-team@meta.com, Breno Leitao X-Mailer: b4 0.15-dev-363b9 X-Developer-Signature: v=1; a=openpgp-sha256; l=2614; i=leitao@debian.org; h=from:subject:message-id; bh=YVhCrOyKP8U5J2m4qj3vibyEe1/805eqdpLycoz/rnY=; b=owEBbQKS/ZANAwAIATWjk5/8eHdtAcsmYgBpwSAXjawQejJ6O0nK22xYUeX44mgycAeLBIErH iNh53nhH6CJAjMEAAEIAB0WIQSshTmm6PRnAspKQ5s1o5Of/Hh3bQUCacEgFwAKCRA1o5Of/Hh3 bVoKEACXFteiy0LDw6XQIHJIVKZv62Rw8SWbJRcuIgms0vpyfrdd8unXMxJg95zu/dVeYuqHeSU 1kzsiDBubWZP5FVjY78icJYKljIFvYAN8iTSxtm0p7Bo3bJNZFzNT3LuuFxn0Mz2VZZuyd2rRwK 3REu3XCpJ9nwBJJbGOcJJULbSOBWLCoGwU30jwLdkAhUMB9yjWzM2HeOLMBYX/QAPfImDqUlhnD TBeYDe3v0tfIwD90cVsFK5XMX5a3fpmEs+XtUlTnei/wq5C6YFniupgVSIPaK1qXkveAWJydqhC aONRXZQDirkpVTiGgJINCd4wGGJZowPFGYfrFa2Tz8DIT6FNgMK2xcKkPQcDSsoXczffddQysQj GQ/iZTKH5sWJvz/hDLsqRaIUPKCdGoYzu89wWIDNrNXw7tVDU7vVcvOPt4XYbWjScUY8KwcfPYP ocAGxIIQg3MO5ZAU8CyOVANa1wEgqRDtUuoLns2o8W/8qBjmkKgWhWouZ7KRBQ4fFBEOT+bJM/Q dZiMrH/zyp53Aqqogq1lFlt8fpeBs2N877EBU4xk1ox9AsuQG8cI8m3B3f7Eg2X1Hmrhz9dfIka l3TZqMxbm7JtZxHOFufSN9U8ZVs4uagZ4OpA4Jr6wwvHCg3kTFtOjbJgOnYaT4KTPsJT8h7lSj3 czqqTsVr9ZRyKvQ== X-Developer-Key: i=leitao@debian.org; a=openpgp; fpr=AC8539A6E8F46702CA4A439B35A3939FFC78776D X-Debian-User: leitao Add a Kconfig option to default kmemleak verbose mode on at build time. This option depends on DEBUG_KMEMLEAK_AUTO_SCAN since verbose reporting is only meaningful when the automatic scanning thread is running. When enabled, kmemleak prints full details (backtrace, hex dump, address) of unreferenced objects to dmesg as they are detected during scanning, removing the need to manually read /sys/kernel/debug/kmemleak. Making this a compile-time option rather than a boot parameter allows debug kernel flavors to enable verbose kmemleak reporting by default without requiring changes to boot arguments. A machine can simply swap to a debug kernel and benefit from kmemleak reporting automatically. By surfacing leak reports directly in dmesg, they are automatically forwarded through any kernel logging infrastructure and can be easily captured by log aggregation tooling, making it practical to monitor memory leaks across large fleets. The verbose setting can still be toggled at runtime via /sys/module/kmemleak/parameters/verbose. Signed-off-by: Breno Leitao Acked-by: Catalin Marinas Acked-by: SeongJae Park Acked-by: Vlastimil Babka (SUSE) Reviewed-by: Lorenzo Stoakes (Oracle) --- mm/Kconfig.debug | 11 +++++++++++ mm/kmemleak.c | 2 +- 2 files changed, 12 insertions(+), 1 deletion(-) diff --git a/mm/Kconfig.debug b/mm/Kconfig.debug index 7638d75b27db8..91b3e027b7535 100644 --- a/mm/Kconfig.debug +++ b/mm/Kconfig.debug @@ -297,6 +297,17 @@ config DEBUG_KMEMLEAK_AUTO_SCAN =20 If unsure, say Y. =20 +config DEBUG_KMEMLEAK_VERBOSE + bool "Default kmemleak to verbose mode" + depends on DEBUG_KMEMLEAK_AUTO_SCAN + help + Say Y here to have kmemleak print unreferenced object details + (backtrace, hex dump, address) to dmesg when new memory leaks are + detected during automatic scanning. This can also be toggled at + runtime via /sys/module/kmemleak/parameters/verbose. + + If unsure, say N. + config PER_VMA_LOCK_STATS bool "Statistics for per-vma locks" depends on PER_VMA_LOCK diff --git a/mm/kmemleak.c b/mm/kmemleak.c index fa8201e232221..2eff0d6b622b6 100644 --- a/mm/kmemleak.c +++ b/mm/kmemleak.c @@ -241,7 +241,7 @@ static int kmemleak_skip_disable; /* If there are leaks that can be reported */ static bool kmemleak_found_leaks; =20 -static bool kmemleak_verbose; +static bool kmemleak_verbose =3D IS_ENABLED(CONFIG_DEBUG_KMEMLEAK_VERBOSE); module_param_named(verbose, kmemleak_verbose, bool, 0600); =20 static void kmemleak_disable(void); --- base-commit: 785f0eb2f85decbe7c1ef9ae922931f0194ffc2e change-id: 20260323-kmemleak_report-a9a103ee0c8c Best regards, -- =20 Breno Leitao