From nobody Tue Sep 29 09:08:10 2026 Received: from mta1.migadu.com (out-57.mta1.migadu.com [95.215.58.57]) (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 A90A23A453B for ; Mon, 10 Aug 2026 09:39:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.57 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786354795; cv=none; b=SW8YlUqbLN+v3rnXDB7Fu78Jn8WISrD+hkbiP+hBk+qXLXMhN2ul7VsaABOWAY1dwFmd//Kkd6W06y2YgfDbCtISL+6RpD8wUbN9Vg1NDrSv/Dl7KZRGaRLF4KhjKsMx8/fOBbtD+zMfVUiyPexivXo6kbw5xxvVtMpPCBCuvro= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786354795; c=relaxed/simple; bh=tlcnQ2gSnDSweAJxKqL+Wd2tfNW+VPS5fl701xcZpzM=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=MSgMbQTxP1LkE4z3vfgELHo9ZLRMg0Gv6uqbb6oeDAbaRSq/zwJ17CO6QNerjG28vd4j7JBlGIuWVj0sL1IUwKRHUVext8aukqkJkUscXDny9F7R5jxH+qQelYJz1aWuYDPNG7k38/cu9YcDE9ikF/kP95hdE5+/FChiM1Q3sQ8= 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=YC8F4hHT; arc=none smtp.client-ip=95.215.58.57 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="YC8F4hHT" X-Envelope-To: linux-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=tlcnQ2gSnDSweAJxKqL+Wd2tfNW+VPS5fl701xcZpzM=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1786354791; v=1; x=1786959591; b=YC8F4hHTWx55rXGpAptdPy4g88G8Qz9fPzJjQZdDgcvrD3DKhC97jLUWaDPS2oGIcyUtd2XP pSrE/6uWI2PVL8BIgyKAo+MP/CRiqa0KNkW0xRCQA9SET90iHJ/UYd+3V+DOupfYLF+0QX8IGxq fpgGEuh17wztX5KZx+SP7uV8= X-Envelope-To: linux-kernel@vger.kernel.org Received: from localhost.localdomain (116.128.244.169) by mta10.migadu.com with ESMTPS id ed45d9bbade2a809; Mon, 10 Aug 2026 09:39:51 +0000 Authentication-Results: mta10.migadu.com; none X-Migadu-Scanner: mta10.migadu.com From: Hao Ge To: Suren Baghdasaryan , Andrew Morton , Luis Chamberlain , Petr Pavlu , Daniel Gomez , Sami Tolvanen , Aaron Tomlin Cc: linux-modules@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Hao Ge Subject: [PATCH v4 1/2] alloc_tag: move release_module_tags() above reserve_module_tags() Date: Mon, 10 Aug 2026 17:39:54 +0800 Message-Id: <20260810093955.153015-2-hao.ge@linux.dev> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20260810093955.153015-1-hao.ge@linux.dev> References: <20260810093955.153015-1-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: quoted-printable Content-Type: text/plain; charset="utf-8" release_module_tags() is a cleanup helper. reserve_module_tags() can also fail after storing the reservation in the maple tree, in which case it should call release_module_tags() to undo it. Move the helper above reserve_module_tags() so no forward declaration is needed. No functional change. Signed-off-by: Hao Ge --- mm/alloc_tag.c | 92 +++++++++++++++++++++++++------------------------- 1 file changed, 46 insertions(+), 46 deletions(-) diff --git a/mm/alloc_tag.c b/mm/alloc_tag.c index 52aece27b00e..af44f90379f2 100644 --- a/mm/alloc_tag.c +++ b/mm/alloc_tag.c @@ -835,6 +835,52 @@ static int vm_module_tags_populate(void) return 0; } =20 +static void release_module_tags(struct module *mod, bool used) +{ + MA_STATE(mas, &mod_area_mt, module_tags.size, module_tags.size); + struct alloc_tag *start_tag; + struct alloc_tag *end_tag; + struct module *val; + + mas_lock(&mas); + mas_for_each_rev(&mas, val, 0) + if (val =3D=3D mod) + break; + + if (!val) /* module not found */ + goto out; + + if (!used) + goto release_area; + + start_tag =3D (struct alloc_tag *)(module_tags.start_addr + mas.index); + end_tag =3D (struct alloc_tag *)(module_tags.start_addr + mas.last); + if (!clean_unused_counters(start_tag, end_tag)) { + struct alloc_tag *tag; + + for (tag =3D start_tag; tag <=3D end_tag; tag++) { + struct alloc_tag_counters counter; + + if (!tag->counters) + continue; + + counter =3D alloc_tag_read(tag); + pr_info("%s:%u module %s func:%s has %llu allocated at module unload\n", + tag->ct.filename, tag->ct.lineno, tag->ct.modname, + tag->ct.function, counter.bytes); + } + } else { + used =3D false; + } +release_area: + mas_store(&mas, used ? &unloaded_mod : NULL); + val =3D mas_prev_range(&mas, 0); + if (val =3D=3D &prepend_mod) + mas_store(&mas, NULL); +out: + mas_unlock(&mas); +} + static void *reserve_module_tags(struct module *mod, unsigned long size, unsigned int prepend, unsigned long align) { @@ -922,52 +968,6 @@ static void *reserve_module_tags(struct module *mod, u= nsigned long size, return (struct alloc_tag *)(module_tags.start_addr + offset); } =20 -static void release_module_tags(struct module *mod, bool used) -{ - MA_STATE(mas, &mod_area_mt, module_tags.size, module_tags.size); - struct alloc_tag *start_tag; - struct alloc_tag *end_tag; - struct module *val; - - mas_lock(&mas); - mas_for_each_rev(&mas, val, 0) - if (val =3D=3D mod) - break; - - if (!val) /* module not found */ - goto out; - - if (!used) - goto release_area; - - start_tag =3D (struct alloc_tag *)(module_tags.start_addr + mas.index); - end_tag =3D (struct alloc_tag *)(module_tags.start_addr + mas.last); - if (!clean_unused_counters(start_tag, end_tag)) { - struct alloc_tag *tag; - - for (tag =3D start_tag; tag <=3D end_tag; tag++) { - struct alloc_tag_counters counter; - - if (!tag->counters) - continue; - - counter =3D alloc_tag_read(tag); - pr_info("%s:%u module %s func:%s has %llu allocated at module unload\n", - tag->ct.filename, tag->ct.lineno, tag->ct.modname, - tag->ct.function, counter.bytes); - } - } else { - used =3D false; - } -release_area: - mas_store(&mas, used ? &unloaded_mod : NULL); - val =3D mas_prev_range(&mas, 0); - if (val =3D=3D &prepend_mod) - mas_store(&mas, NULL); -out: - mas_unlock(&mas); -} - static int load_module(struct module *mod, struct codetag *start, struct c= odetag *stop) { /* Allocate module alloc_tag percpu counters */ --=20 2.25.1 From nobody Tue Sep 29 09:08:10 2026 Received: from mta1.migadu.com (out-67.mta1.migadu.com [95.215.58.67]) (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 E26353B0AE2 for ; Mon, 10 Aug 2026 09:40:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.67 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786354809; cv=none; b=oL1hKddl4VRTYXKw2R4vtqdy3UX2BRg5eFisnShOYzo4H/JKgbFTUbVi/L/uq2Ef+rDO9lHN9Ee3CUvaRY4ptUrG1q8bcWiiwn3VQGf8mIz0f6906gY/DWuIrxkohwROyG8rojJmD1h8eaprZrLQqGxRKOiLy0piUXwFyLuLJnc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786354809; c=relaxed/simple; bh=+7z3AP/ISNgtjS8Lqlp+ZNKMBFC0XbB0Gkd40yGE6eg=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=jDQU3Gh6mlQpI/spKUWbRJb4rUXl/g1mp5RlIeS+FpvsyVgqGbpN7tSeTRTzfl6JrLmqL985L1TaAF9uuTqmCOkynRa/lhBYue9/f71H1TC0SjzIJR32Crq1qEEQJgrw5A+KxEwoJUqaBgOO9nk+PeEwz85Ia9bZHw6pLzBLytY= 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=X6JETdJL; arc=none smtp.client-ip=95.215.58.67 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="X6JETdJL" X-Envelope-To: linux-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=+7z3AP/ISNgtjS8Lqlp+ZNKMBFC0XbB0Gkd40yGE6eg=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1786354805; v=1; x=1786959605; b=X6JETdJLrNicIKajmnhxVTliKWjVG6cxTJow4sXQbILvCLiOXKsj1tEzo26qKwfiQ6S8BA+p XBBnPYe9+SwRw28+z938Zw4v/cTGcAmm7fp0KqIWYer0e0+XqfAbf4a71KvR+ElfK9ehdVX+6xJ F49syguUdUm0vLDLSDXRS+OY= X-Envelope-To: linux-kernel@vger.kernel.org Received: from localhost.localdomain (116.128.244.169) by mta10.migadu.com with ESMTPS id 52b4c21b50599e27; Mon, 10 Aug 2026 09:40:05 +0000 X-Migadu-Scanner: mta10.migadu.com Authentication-Results: mta10.migadu.com; none From: Hao Ge To: Suren Baghdasaryan , Andrew Morton , Luis Chamberlain , Petr Pavlu , Daniel Gomez , Sami Tolvanen , Aaron Tomlin Cc: linux-modules@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Hao Ge , stable@vger.kernel.org Subject: [PATCH v4 2/2] alloc_tag: fix undetected compressed tag overflow when profiling is disabled Date: Mon, 10 Aug 2026 17:39:55 +0800 Message-Id: <20260810093955.153015-3-hao.ge@linux.dev> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20260810093955.153015-1-hao.ge@linux.dev> References: <20260810093955.153015-1-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: quoted-printable Content-Type: text/plain; charset="utf-8" In reserve_module_tags(), the tag overflow check is gated on mem_alloc_profiling_enabled(): if (mem_alloc_profiling_enabled() && !tags_addressable()) If profiling is toggled off at runtime and a module is loaded whose tags exceed the compressed-mode limit, shutdown_mem_profiling() is skipped. vm_module_tags_populate() still maps memory for the tags and the module loads successfully, but the total tag count now exceeds what NR_UNUSED_PAGEFLAG_BITS can address. Once profiling is re-enabled, ref_to_idx() computes each tag's index as its position in the alloc_tag array. update_page_tag_ref() masks it to alloc_tag_ref_mask before storing in page->flags. Indices beyond the mask are truncated and idx_to_ref() resolves them to wrong tags. This silently corrupts /proc/allocinfo: allocated pages get attributed to the wrong call sites, so the statistics it reports are wrong. mem_alloc_profiling_enabled() and mem_profiling_compressed are independent. Once compressed mode is established at boot, it stays active regardless of runtime toggles of mem_profiling. Remove the mem_alloc_profiling_enabled() guard. On overflow, shut down profiling, release the reservation, and return -EAGAIN so that layout_and_allocate() retries with profiling disabled: codetag sections are then placed as regular module data and the module loads without profiling rather than being rejected entirely. Skip percpu counter allocation in load_module() when profiling is disabled, as those counters would never be freed on unload. Fixes: 4835f747d3ed ("alloc_tag: support for page allocation tag compressio= n") Cc: stable@vger.kernel.org Suggested-by: Suren Baghdasaryan Signed-off-by: Hao Ge --- kernel/module/main.c | 17 +++++++++++++++-- mm/alloc_tag.c | 11 ++++++++--- 2 files changed, 23 insertions(+), 5 deletions(-) diff --git a/kernel/module/main.c b/kernel/module/main.c index 46dd8d25a605..c32bb47a573a 100644 --- a/kernel/module/main.c +++ b/kernel/module/main.c @@ -2971,13 +2971,26 @@ static struct module *layout_and_allocate(struct lo= ad_info *info, int flags) * this is done generically; there doesn't appear to be any * special cases for the architectures. */ +retry: layout_sections(info->mod, info); layout_symtab(info->mod, info); =20 /* Allocate and move to the final place */ err =3D move_module(info->mod, info); - if (err) - return ERR_PTR(err); + if (err) { + if (err !=3D -EAGAIN) + return ERR_PTR(err); + /* + * -EAGAIN means profiling was disabled but the module + * can still load without it. Reset state and retry. + */ + rewrite_section_headers(info, flags); + for_each_mod_mem_type(type) + info->mod->mem[type].size =3D 0; + info->sechdrs[info->index.sym].sh_flags &=3D ~(unsigned long)SHF_ALLOC; + info->sechdrs[info->index.str].sh_flags &=3D ~(unsigned long)SHF_ALLOC; + goto retry; + } =20 /* Module has been copied to its final place now: return it. */ mod =3D (void *)info->sechdrs[info->index.mod].sh_addr; diff --git a/mm/alloc_tag.c b/mm/alloc_tag.c index af44f90379f2..3eba6331174d 100644 --- a/mm/alloc_tag.c +++ b/mm/alloc_tag.c @@ -950,10 +950,12 @@ static void *reserve_module_tags(struct module *mod, = unsigned long size, int grow_res; =20 module_tags.size =3D offset + size; - if (mem_alloc_profiling_enabled() && !tags_addressable()) { + if (!tags_addressable()) { shutdown_mem_profiling(true); - pr_warn("With module %s there are too many tags to fit in %d page flag = bits. Memory allocation profiling is disabled!\n", - mod->name, NR_UNUSED_PAGEFLAG_BITS); + pr_warn_once("With module %s there are too many tags to fit in %d page = flag bits. Memory allocation profiling is disabled!\n", + mod->name, NR_UNUSED_PAGEFLAG_BITS); + release_module_tags(mod, false); + return ERR_PTR(-EAGAIN); } =20 grow_res =3D vm_module_tags_populate(); @@ -975,6 +977,9 @@ static int load_module(struct module *mod, struct codet= ag *start, struct codetag struct alloc_tag *stop_tag; struct alloc_tag *tag; =20 + if (!mem_profiling_support) + return 0; + /* percpu counters for core allocations are already statically allocated = */ if (!mod) return 0; --=20 2.25.1