From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mta0.migadu.com (out-117.mta0.migadu.com [91.218.175.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id F37AA2D877A for ; Mon, 17 Aug 2026 06:26:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.117 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786948021; cv=none; b=ULWqF9lLOc6F47KZMSDb/SHp7OkGqA6AsNs/3AIzxyG66A3TcWV+Ya5ElZywd8ddfsE/iI4N4mILZP0YRAg1Naigu3LRY1PHyWpasys/PsHzMKPfhSizBehX1lJar4JRPAuEgRXBGUBSt0Efk9nxJDgKTdhu6ytxddJMRAdRYVU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786948021; c=relaxed/simple; bh=Nrl5tHbT9eQhQhzooTC92+qQ11qduWmutBe6i3Oleeo=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=oQETDCDYRu5BXfYk8OBxfIrYGc7cULoUQ1WAXJaqtmwDuna2Xyh47IOPbsjlAVTy4w42IdhLmX3+tdqtCZvwH7gSCSN3mg1YMztjNuxNIvYJVM8y9PO8LHvKYUU7QO6jqn6ho+pGLOtuet5+5197V0nNb8H9BvdFNqhov/WVlSY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=f6LbZYdJ; arc=none smtp.client-ip=91.218.175.117 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="f6LbZYdJ" X-Envelope-To: linux-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=Nrl5tHbT9eQhQhzooTC92+qQ11qduWmutBe6i3Oleeo=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1786948017; v=1; x=1787552817; b=f6LbZYdJbh+RYFONAlNMXgMCY6QH0m73I0gQkFwtcV5vUoPEq1W0rJI/BDaJSUr6yKX2kkcP 57tl03izkRjx3CJv6Cr3Qab9i8hMy4S612po1osOSA0X/X60Qn+N0O8O50qNuWvFRbuRC2R7WrE e+HDGPSYtiVd7lQZ0fgYrbaE= X-Envelope-To: linux-kernel@vger.kernel.org Received: from localhost.localdomain (116.128.244.169) by smtp.migadu.com with ESMTPS id 411436bb243080ca; Mon, 17 Aug 2026 06:26:57 +0000 X-Migadu-Flow: FLOW_OUT From: Hao Ge To: Suren Baghdasaryan , Kent Overstreet , Andrew Morton Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Hao Ge , Sashiko , stable@vger.kernel.org Subject: [PATCH 1/2] alloc_tag: skip percpu counter allocation when profiling is disabled Date: Mon, 17 Aug 2026 14:27:25 +0800 Message-Id: <20260817062726.106511-2-hao.ge@linux.dev> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20260817062726.106511-1-hao.ge@linux.dev> References: <20260817062726.106511-1-hao.ge@linux.dev> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit After shutdown_mem_profiling() clears mem_profiling_support, needs_section_mem() returns false, so later modules have their codetag section placed as regular data and never enter the alloc_tag maple tree. codetag_load_module() still called load_module(), which allocated a percpu counter for every tag; release_module_tags() could not find these modules on unload, so the counters leaked. Return -EOPNOTSUPP from load_module() when profiling is off: codetag_module_init() drops the module's cmod, no counters are allocated and the module loads without its tags. codetag_unload_module() now always calls free_section_mem(), since a module whose module_load() returned -EOPNOTSUPP is not in the idr but may still hold a reserved section. Reported-by: Sashiko Fixes: 4835f747d3ed ("alloc_tag: support for page allocation tag compression") Cc: stable@vger.kernel.org Suggested-by: Suren Baghdasaryan Signed-off-by: Hao Ge --- lib/codetag.c | 10 ++++++++-- mm/alloc_tag.c | 4 ++++ 2 files changed, 12 insertions(+), 2 deletions(-) diff --git a/lib/codetag.c b/lib/codetag.c index a9cda4c962a3..a0b600720afc 100644 --- a/lib/codetag.c +++ b/lib/codetag.c @@ -240,7 +240,9 @@ static int codetag_module_init(struct codetag_type *cttype, struct module *mod) if (err < 0) { kfree(cmod); - return err; + /* -EOPNOTSUPP means we can load the module without its tag. */ + if (err != -EOPNOTSUPP) + return err; } return 0; @@ -388,7 +390,11 @@ void codetag_unload_module(struct module *mod) ++cttype->content_id; } up_write(&cttype->mod_lock); - if (found && cttype->desc.free_section_mem) + /* + * A module whose module_load() returned -EOPNOTSUPP is not + * in the idr but may still hold reserved section memory. + */ + if (cttype->desc.free_section_mem) cttype->desc.free_section_mem(mod, true); } mutex_unlock(&codetag_lock); diff --git a/mm/alloc_tag.c b/mm/alloc_tag.c index 52aece27b00e..80eccaca665a 100644 --- a/mm/alloc_tag.c +++ b/mm/alloc_tag.c @@ -975,6 +975,10 @@ static int load_module(struct module *mod, struct codetag *start, struct codetag struct alloc_tag *stop_tag; struct alloc_tag *tag; + /* Profiling disabled: load the module without its tags. */ + if (!mem_profiling_support) + return -EOPNOTSUPP; + /* percpu counters for core allocations are already statically allocated */ if (!mod) return 0; -- 2.25.1