From mboxrd@z Thu Jan 1 00:00:00 1970 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: 7bit 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; addr = PAGE_ALIGN_DOWN((unsigned long) object); - vn = addr_to_node(addr); - 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 = NULL; + for_each_vmap_node(vn) { + if (!spin_trylock(&vn->busy.lock)) + continue; + + va = __find_vmap_area(addr, &vn->busy.root); + if (va && va->vm) + break; - va = __find_vmap_area(addr, &vn->busy.root); - if (!va || !va->vm) { spin_unlock(&vn->busy.lock); - return false; + va = NULL; } + if (!va) + return false; + vm = va->vm; addr = (unsigned long) vm->addr; caller = vm->caller; -- 2.25.1