From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 C6D28380FE3; Thu, 20 Aug 2026 15:19:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787239154; cv=none; b=BfjdNoPXF9ZJkE+t+OA7RlIF/4f/VX5XdiAi0Xjhb13q7SukpIGih1BLfJc6ctgR8Dn4Ozc1ecvkcDDfM103vm2Rv7XHAwz5Y5/3PI4TKE8Py3Wqq/7Q0qWSTRVKUorVuDffETm3Q8MFQiPws/gE5jElm/4fFsjkFOl7Lncuffg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787239154; c=relaxed/simple; bh=KBa3qy9ma7meQD1I5Y/UJQfkEI3isc9832yJqosZOlg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ISPR6HGbaJJX3Ho7A9wHqNV8XelVga9/gbI6KLzsc9ltnBnURiVajyIwlwpXbofT3z62HdPucfvuW9rod3CmFz/eW3LQJh9xMsFWudSrcTN2kmcZy7fzVVdhrjrE5E53YLRW3yFpjYsG/CpH8+i1aZldHsHOs7G5ed52oVLo5Kw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=LryujYME; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="LryujYME" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2D01B1F000E9; Thu, 20 Aug 2026 15:19:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1787239152; bh=nFnm9U7Y5blz9BitjgFRNXyALvdARzdAQG0nGwjBAIA=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=LryujYMEaLC1QTOETm7vHIL1Oe9u9l+hHVxN/gVWjg226JFJhWDoI5R+cekocEiXl HnEPZkZcyV0H0+1RFtz9Cg3Rseq30cnOrj3idISaeu9CMjdu7mynxQkNXSXO4MIGBo 1iPtzy8QIbdpZ3g2sXs8PYujX6m2navBR+R5r0UQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, "Steven Rostedt (Google)" , Vincent Donnefort , Sasha Levin Subject: [PATCH 6.18 161/217] ring-buffer: Store bpage pointers into subbuf_ids Date: Thu, 20 Aug 2026 16:55:29 +0200 Message-ID: <20260820145242.597876326@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260820145237.531699751@linuxfoundation.org> References: <20260820145237.531699751@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Vincent Donnefort [ Upstream commit e682207bf7ae3f81885f612ada1ac44d027158d4 ] The subbuf_ids field allows to point to a specific page from the ring-buffer based on its ID. As a preparation or the upcoming ring-buffer remote support, point this array to the buffer_page instead of the buffer_data_page. Link: https://patch.msgid.link/20260309162516.2623589-3-vdonnefort@google.com Reviewed-by: Steven Rostedt (Google) Signed-off-by: Vincent Donnefort Signed-off-by: Steven Rostedt (Google) Stable-dep-of: 7c727dfce6be ("ring-buffer: Prevent resizing of persistent ring buffer") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- kernel/trace/ring_buffer.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -557,7 +557,7 @@ struct ring_buffer_per_cpu { unsigned int mapped; unsigned int user_mapped; /* user space mapping */ struct mutex mapping_lock; - unsigned long *subbuf_ids; /* ID to subbuf VA */ + struct buffer_page **subbuf_ids; /* ID to subbuf VA */ struct trace_buffer_meta *meta_page; struct ring_buffer_cpu_meta *ring_meta; @@ -7039,7 +7039,7 @@ static void rb_free_meta_page(struct rin } static void rb_setup_ids_meta_page(struct ring_buffer_per_cpu *cpu_buffer, - unsigned long *subbuf_ids) + struct buffer_page **subbuf_ids) { struct trace_buffer_meta *meta = cpu_buffer->meta_page; unsigned int nr_subbufs = cpu_buffer->nr_pages + 1; @@ -7048,7 +7048,7 @@ static void rb_setup_ids_meta_page(struc int id = 0; id = rb_page_id(cpu_buffer, cpu_buffer->reader_page, id); - subbuf_ids[id++] = (unsigned long)cpu_buffer->reader_page->page; + subbuf_ids[id++] = cpu_buffer->reader_page; cnt++; first_subbuf = subbuf = rb_set_head_page(cpu_buffer); @@ -7058,7 +7058,7 @@ static void rb_setup_ids_meta_page(struc if (WARN_ON(id >= nr_subbufs)) break; - subbuf_ids[id] = (unsigned long)subbuf->page; + subbuf_ids[id] = subbuf; rb_inc_page(&subbuf); id++; @@ -7067,7 +7067,7 @@ static void rb_setup_ids_meta_page(struc WARN_ON(cnt != nr_subbufs); - /* install subbuf ID to kern VA translation */ + /* install subbuf ID to bpage translation */ cpu_buffer->subbuf_ids = subbuf_ids; meta->meta_struct_len = sizeof(*meta); @@ -7223,13 +7223,15 @@ static int __rb_map_vma(struct ring_buff } while (p < nr_pages) { + struct buffer_page *subbuf; struct page *page; int off = 0; if (WARN_ON_ONCE(s >= nr_subbufs)) return -EINVAL; - page = virt_to_page((void *)cpu_buffer->subbuf_ids[s]); + subbuf = cpu_buffer->subbuf_ids[s]; + page = virt_to_page((void *)subbuf->page); for (; off < (1 << (subbuf_order)); off++, page++) { if (p >= nr_pages) @@ -7256,7 +7258,8 @@ int ring_buffer_map(struct trace_buffer struct vm_area_struct *vma) { struct ring_buffer_per_cpu *cpu_buffer; - unsigned long flags, *subbuf_ids; + struct buffer_page **subbuf_ids; + unsigned long flags; int err; if (!cpumask_test_cpu(cpu, buffer->cpumask)) @@ -7280,7 +7283,7 @@ int ring_buffer_map(struct trace_buffer if (err) return err; - /* subbuf_ids include the reader while nr_pages does not */ + /* subbuf_ids includes the reader while nr_pages does not */ subbuf_ids = kcalloc(cpu_buffer->nr_pages + 1, sizeof(*subbuf_ids), GFP_KERNEL); if (!subbuf_ids) { rb_free_meta_page(cpu_buffer);