From nobody Thu Sep 24 18:37:43 2026 Received: from mta0.migadu.com (out-200.mta0.migadu.com [91.218.175.200]) (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 4D93033A6F1 for ; Mon, 21 Sep 2026 13:17:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.200 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789996672; cv=none; b=gx3X6MqYRcX9oloKrbdSw7CmcCCd4kW3h/9czUc6PXcas2+MSBOATnnKZmMts9BagEfB10M9zFMhYEjYzSzsmCai+TQyajcD2IomqO6GCScxRhb5oBVac7MobKtyfBIAi82vsr6PxTu52LIJbrWzmigY13z4jqyrDg049JJIV20= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789996672; c=relaxed/simple; bh=TgBqgmk/OGkiRG4oFsrkPk1fFb54WBL3zueWiSKqe7I=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=bKuHwW5gAhih42Dy4ItY2Jg9E+cwqqxWvCafEgGEeO7Bz6/JTRprKCDnQ6hZNXcoBLiLogFJYRpaEC+L7a6IOHLNPaqv40pjfG+ciXPjsqe6HF+TfqHDGvsVZNW34aOqVZzsO5pIuiaw4qoTlxeCSix8KoWO0EN01NbfCxT3vzQ= 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=E4vNZoGT; arc=none smtp.client-ip=91.218.175.200 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="E4vNZoGT" X-Envelope-To: linux-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=TgBqgmk/OGkiRG4oFsrkPk1fFb54WBL3zueWiSKqe7I=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1789996668; v=1; x=1790601468; b=E4vNZoGT1Z9K7ZSq8aTtO8JWLC+bxKugBY5+nu/e0Zu3M/HhYKxssxvflfUQqzbWM2Sqsywx 4uitAdpslgeTvro0v2ET1uPLP9ZOv/xjnkybrDjkoDcwmX9b4o8R8L3iFKziwWVv8bw0FRMvnus Ih7RxqEmgQ1AADo942YiqV48= X-Envelope-To: linux-kernel@vger.kernel.org Received: by smtp.migadu.com with ESMTPS id f052238703df67d5; Mon, 21 Sep 2026 13:17:48 +0000 X-Mizu-Trace-ID: f052238703df67d5 X-Migadu-Flow: FLOW_OUT From: Ye Liu Date: Mon, 21 Sep 2026 21:17:21 +0800 Subject: [PATCH v2 1/3] mm/vmalloc: fix vmalloc_dump_obj address alignment for last-page lookups 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: <20260921-vmalloc_dump_obj-v2-1-73fceb3ed1c8@linux.dev> References: <20260921-vmalloc_dump_obj-v2-0-73fceb3ed1c8@linux.dev> In-Reply-To: <20260921-vmalloc_dump_obj-v2-0-73fceb3ed1c8@linux.dev> To: Andrew Morton , Uladzislau Rezki , Paul Walmsley , Palmer Dabbelt , Albert Ou , Alexandre Ghiti Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, Ye Liu X-Mailer: b4 0.14.3 From: Ye Liu vmalloc_dump_obj() uses PAGE_ALIGN() to normalize the input address before looking it up in the per-node busy tree. PAGE_ALIGN() rounds up, which can push an address in the last page of a vmalloc allocation to va_end -- outside the [va_start, va_end) range that __find_vmap_area() searches. This causes the lookup to miss the VA and return false, degrading diagnostic output in OOM dumps and KASAN reports to the less informative "vmalloc memory" fallback. The upward alignment can also change the addr_to_node() mapping when the page boundary crosses a vmap zone boundary, causing the search to hit the wrong node entirely. Use PAGE_ALIGN_DOWN() instead, which rounds down to the page containing the address. This keeps the address within the VA range and preserves the correct node mapping. Signed-off-by: Ye Liu Reviewed-by: Uladzislau Rezki (Sony) --- mm/vmalloc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 859e6d2d57a3..df42d8a6f058 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -5277,7 +5277,7 @@ bool vmalloc_dump_obj(void *object) unsigned long addr; unsigned long nr_pages; =20 - addr =3D PAGE_ALIGN((unsigned long) object); + addr =3D PAGE_ALIGN_DOWN((unsigned long) object); vn =3D addr_to_node(addr); =20 if (!spin_trylock(&vn->busy.lock)) --=20 2.25.1 From nobody Thu Sep 24 18:37:43 2026 Received: from mta1.migadu.com (out-59.mta1.migadu.com [95.215.58.59]) (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 EE44F33A6F1 for ; Mon, 21 Sep 2026 13:17:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.59 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789996678; cv=none; b=uNiqGNKJRkJHgC+xmRCoy3JcmnMUGUVFjynqalnwWZnTPiGBSxLpHiM1YF0K6oXSs/KmJ0eKgBndASM2xnssTOagqGRE7ysAfRlUXTC2tijqh8ffHaEEvbdFnbU1yL2TQK/6I+gXs4tjlxpgbMNmkyxL7vJcKmnNOfKloOawrew= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789996678; c=relaxed/simple; bh=ueVOpPzYnMeot+dswpS82YrnsBHSSPYd5K+PQjCvvaY=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=UvfPIte3wlx9QupiSQc6Z+8FweA9NXnByNAQA22wPwmrmKKTLDKG5v65csKNVCUt/URSLn1cMoT+jAueyuKnPms/iruhpT6l1ecUM3ys2T0IXYX7fS72+IRTz+8SH70yOpZfO5D3KQfawR2CnNzNBrlSPVZNgJnZf8a/cz1TlVo= 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=X/SjqYcJ; arc=none smtp.client-ip=95.215.58.59 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="X/SjqYcJ" X-Envelope-To: linux-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=ueVOpPzYnMeot+dswpS82YrnsBHSSPYd5K+PQjCvvaY=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1789996674; v=1; x=1790601474; b=X/SjqYcJokzG5Jzyk6IVWxAXA+B4Xm2zy1fhXRgjy9ZEfXBQNe028meEjtHeHVkI9ZGDZo0U vBCYfFcQl7QxHlYUPwMhSmzQ9JxpQNVX7LiAOzX4bRqgCdd6x7u/k1nBG4zy91iUNa8YHVRUDCW AjTsvty9tppeRrskQ66c1STU= X-Envelope-To: linux-kernel@vger.kernel.org Received: by smtp.migadu.com with ESMTPS id f48b4f0c2c5289ef; Mon, 21 Sep 2026 13:17:54 +0000 X-Mizu-Trace-ID: f48b4f0c2c5289ef X-Migadu-Flow: FLOW_OUT From: Ye Liu Date: Mon, 21 Sep 2026 21:17:22 +0800 Subject: [PATCH v2 2/3] mm/vmalloc: fix vmalloc_dump_obj cross-zone VA lookup 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: <20260921-vmalloc_dump_obj-v2-2-73fceb3ed1c8@linux.dev> References: <20260921-vmalloc_dump_obj-v2-0-73fceb3ed1c8@linux.dev> In-Reply-To: <20260921-vmalloc_dump_obj-v2-0-73fceb3ed1c8@linux.dev> To: Andrew Morton , Uladzislau Rezki , Paul Walmsley , Palmer Dabbelt , Albert Ou , Alexandre Ghiti Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, Ye Liu X-Mailer: b4 0.14.3 From: Ye Liu vmalloc_dump_obj() searches only one vmap node (addr_to_node(addr)), but a vmalloc allocation may span multiple vmap zones. The VA is stored in only one node's rb-tree (addr_to_node(va_start)), so an object pointer in a different zone than va_start maps to a different node and the search misses. This affects any allocation larger than vmap_zone_size (64 KiB) on multi-CPU systems. Iterate all vmap nodes using for_each_vmap_node, like find_vmap_area() does, but with spin_trylock instead of spin_lock as this function can be called from atomic dump contexts (OOM, KASAN, RCU). Signed-off-by: Ye Liu --- mm/vmalloc.c | 24 ++++++++++++++++++------ 1 file changed, 18 insertions(+), 6 deletions(-) diff --git a/mm/vmalloc.c b/mm/vmalloc.c index df42d8a6f058..30c610f678dc 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -5278,17 +5278,29 @@ bool vmalloc_dump_obj(void *object) unsigned long nr_pages; =20 addr =3D PAGE_ALIGN_DOWN((unsigned long) object); - vn =3D addr_to_node(addr); =20 - if (!spin_trylock(&vn->busy.lock)) - return false; + /* + * A vmalloc allocation may span multiple vmap zones, so the + * node whose rb-tree holds the VA may differ from the node + * the address maps to. Search all nodes. Use trylock as + * this function can be called from atomic dump contexts. + */ + va =3D NULL; + for_each_vmap_node(vn) { + if (!spin_trylock(&vn->busy.lock)) + continue; + + va =3D __find_vmap_area(addr, &vn->busy.root); + if (va && va->vm) + break; =20 - va =3D __find_vmap_area(addr, &vn->busy.root); - if (!va || !va->vm) { spin_unlock(&vn->busy.lock); - return false; + va =3D NULL; } =20 + if (!va) + return false; + vm =3D va->vm; addr =3D (unsigned long) vm->addr; caller =3D vm->caller; --=20 2.25.1 From nobody Thu Sep 24 18:37:43 2026 Received: from mta0.migadu.com (out-210.mta0.migadu.com [91.218.175.210]) (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 019D149E134 for ; Mon, 21 Sep 2026 13:18:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.210 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789996684; cv=none; b=quHt1uvlEgcLuSF1B2V3YL3pnSs6NhEZvM9vK+yTtikW1f8DuGBoqFIEIpGp1J2DwLCemakn0hbp2yb3jekDULPmYYwzIRMzlq4a3PyYHPErRsH/ST/K9ILfCFs8+CLkW/bYeBlwapV2MugDEvC9zDQuchthWZ+jZNfD+LPHIOI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789996684; c=relaxed/simple; bh=IN3u//Q3+OpLA8rMnVjE8v9xBIK2AikPADGADNf418I=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=f6n5gGQ9MBXWZr8LbfYduSA8VXgD5bmSXgtna0ywbLmBd1gTnwxpACOwN5S4NClJjUHieB5cAbQn4WFMNcxDSzUuuztdtoebZjFYXdmHJQIMxRCjiHf9g5OmwPa4ANs0gU5HTSOrNnaFBT2FNpf0t1ugpRukkDVd/q3SZYqJTqo= 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=myA1+5KR; arc=none smtp.client-ip=91.218.175.210 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="myA1+5KR" X-Envelope-To: linux-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=IN3u//Q3+OpLA8rMnVjE8v9xBIK2AikPADGADNf418I=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1789996681; v=1; x=1790601481; b=myA1+5KRkTOpFpgN9Q7qgN+XSlBivE/MVPxxYjs+yMiMagjddcNTGevuYj+9z2O5eA4TEJQt X0YPrWdUw+XglWLP4iIDUMuTvTxoEvNYtoUhP968mOD6fsh+JU8gbRzxTXlARXkD5e7AQkcp5M7 5HngVexuaiONVCvxe8lRki60= X-Envelope-To: linux-kernel@vger.kernel.org Received: by smtp.migadu.com with ESMTPS id 28b20bafde2dc762; Mon, 21 Sep 2026 13:18:00 +0000 X-Mizu-Trace-ID: 28b20bafde2dc762 X-Migadu-Flow: FLOW_OUT From: Ye Liu Date: Mon, 21 Sep 2026 21:17:23 +0800 Subject: [PATCH v2 3/3] mm/vmalloc: skip vmalloc_dump_obj for non-vmalloc addresses 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: <20260921-vmalloc_dump_obj-v2-3-73fceb3ed1c8@linux.dev> References: <20260921-vmalloc_dump_obj-v2-0-73fceb3ed1c8@linux.dev> In-Reply-To: <20260921-vmalloc_dump_obj-v2-0-73fceb3ed1c8@linux.dev> To: Andrew Morton , Uladzislau Rezki , Paul Walmsley , Palmer Dabbelt , Albert Ou , Alexandre Ghiti Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, Ye Liu X-Mailer: b4 0.14.3 From: Ye Liu vmalloc_dump_obj() unconditionally searches all vmap nodes even when called with a non-vmalloc address (e.g. a slab or stack pointer from mem_dump_obj()). Add an is_vmalloc_or_module_addr() check at the entry to avoid the unnecessary per-node trylock and rb-tree traversal. Use is_vmalloc_or_module_addr() rather than is_vmalloc_addr() because module, BPF, and execmem allocations reside in MODULES_VADDR..MODULES_END on x86_64, arm64, and riscv -- outside VMALLOC_START..VMALLOC_END -- but are still tracked in the same vmap_nodes rb-tree. Signed-off-by: Ye Liu --- mm/vmalloc.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 30c610f678dc..d8095b558365 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -5277,6 +5277,9 @@ bool vmalloc_dump_obj(void *object) unsigned long addr; unsigned long nr_pages; =20 + if (!is_vmalloc_or_module_addr(object)) + return false; + addr =3D PAGE_ALIGN_DOWN((unsigned long) object); =20 /* --=20 2.25.1