From nobody Fri Dec 19 15:17:24 2025 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 4DD6E19D880 for ; Tue, 27 Aug 2024 09:27:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724750824; cv=none; b=d9DUsAwjp6PFzH44SMAV+G92CNFjDm/kb82Lp7tF+/PsE7Z6udBIQZxYJkJS2+i8MJ2Z84ugH5PuuUmP7aqudDfr3HInokV4F/n2DEeQla7mB0RN9oFD2ArMJCxXDV6qAJXJ/uKaWz9doNF3vp1WRnmB0vjV4kdm9aJE7helefI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724750824; c=relaxed/simple; bh=jUK1kJgfhcwf8nhkQ4JSyJF9SwO8DOZ1x0fWmhdFtvw=; h=Message-ID:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=QdzSXD+hOzgsYvjsloeuLjDjdKsyKKLc7bzW5UbHZUwR3xU8W5XQSALE23yvsTkpCcz7vrdida0vvH8TPSIo5IwX9Laz2SiZK/GBYBUwPw4WoV7scDcy/5hLujv9u+s6b34hnnFA2RoaXQuUXZ7yRvV9sZNU5Pa199PWPU2EWGw= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 Received: by smtp.kernel.org (Postfix) with ESMTPSA id D5BE3C8B7B7; Tue, 27 Aug 2024 09:27:03 +0000 (UTC) Received: from rostedt by gandalf with local (Exim 4.98) (envelope-from ) id 1sisUM-00000004SLF-244v; Tue, 27 Aug 2024 05:27:46 -0400 Message-ID: <20240827092746.359657809@goodmis.org> User-Agent: quilt/0.68 Date: Tue, 27 Aug 2024 05:27:18 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Masami Hiramatsu , Mark Rutland , Mathieu Desnoyers , Andrew Morton , Vincent Donnefort Subject: [for-next][PATCH 2/8] ring-buffer: Add magic and struct size to boot up meta data References: <20240827092716.515115830@goodmis.org> 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" From: Steven Rostedt Add a magic number as well as save the struct size of the ring_buffer_meta structure in the meta data to also use as validation. Updating the magic number could be used to force a invalidation between kernel versions, and saving the structure size is also a good method to make sure the content is what is expected. Cc: Masami Hiramatsu Cc: Mathieu Desnoyers Cc: Vincent Donnefort Link: https://lore.kernel.org/20240815115032.0c197b32@rorschach.local.home Signed-off-by: Steven Rostedt (Google) --- kernel/trace/ring_buffer.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index b16f301b8a93..c3a5e6cbb940 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -44,7 +44,11 @@ =20 static void update_pages_handler(struct work_struct *work); =20 +#define RING_BUFFER_META_MAGIC 0xBADFEED + struct ring_buffer_meta { + int magic; + int struct_size; unsigned long text_addr; unsigned long data_addr; unsigned long first_buffer; @@ -1627,6 +1631,13 @@ static bool rb_meta_valid(struct ring_buffer_meta *m= eta, int cpu, unsigned long buffers_end; int i; =20 + /* Check the meta magic and meta struct size */ + if (meta->magic !=3D RING_BUFFER_META_MAGIC || + meta->struct_size !=3D sizeof(*meta)) { + pr_info("Ring buffer boot meta[%d] mismatch of magic or struct size\n", = cpu); + return false; + } + /* The subbuffer's size and number of subbuffers must match */ if (meta->subbuf_size !=3D subbuf_size || meta->nr_subbufs !=3D nr_pages + 1) { @@ -1858,6 +1869,9 @@ static void rb_range_meta_init(struct trace_buffer *b= uffer, int nr_pages) =20 memset(meta, 0, next_meta - (void *)meta); =20 + meta->magic =3D RING_BUFFER_META_MAGIC; + meta->struct_size =3D sizeof(*meta); + meta->nr_subbufs =3D nr_pages + 1; meta->subbuf_size =3D PAGE_SIZE; =20 --=20 2.43.0