From patchwork Sat Oct 19 19:29:51 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steven Rostedt X-Patchwork-Id: 13842875 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 39252A59; Sat, 19 Oct 2024 19:29:54 +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=1729366195; cv=none; b=hRN6rL7fcCMbV03V+z4IUAJzeopariZaxyKmya9M9uPDk5oO4Oiuq6c5YkanrEinn6Ezh0JlJu78GEpGLTQho+nkm9piZb8fLe0TNfKpL14F3e2xb4sD6kv9kbO9f7p2O4Qyra2KhCiGjCcQIehgMQe55mK3x4nOFKiJObbRFWE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729366195; c=relaxed/simple; bh=e/bZ/6qu4+8ZIh7lBsxWSX2qAbUed7FU+h5KuxoPDuQ=; h=Date:From:To:Cc:Subject:Message-ID:MIME-Version:Content-Type; b=kf2lyulUKcADe//mt/ReG7ZmohWLE/bg563RdP4G7cB6yeG+06ayjY7CWf7zZfSrKTxaM9vUhpRlm6ZZG2Xg723nReFx2dltVRqIpKbljGQgVw6t0u0P8lPOTlSGzC3JWUhlFkPtxFHhalZaM3DT0LR5QoZrM1cAz6bcaPrQzTc= 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 91AC1C4CEC5; Sat, 19 Oct 2024 19:29:53 +0000 (UTC) Date: Sat, 19 Oct 2024 15:29:51 -0400 From: Steven Rostedt To: LKML , Linux trace kernel Cc: Masami Hiramatsu , Mark Rutland , Mathieu Desnoyers , Ryan Roberts Subject: [PATCH] fgraph: Separate size of ret_stack from PAGE_SIZE Message-ID: <20241019152951.053f9646@rorschach.local.home> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Steven Rostedt The ret_stack (shadow stack used by function graph infrastructure) is currently defined as PAGE_SIZE. But some architectures which have 64K PAGE_SIZE, this is way overkill. Also there's an effort to allow the PAGE_SIZE to be defined at boot up. Hard code it for now to 4096. In the future, this size may change and even be dependent on specific architectures. Link: https://lore.kernel.org/all/e5067bb8-0fcd-4739-9bca-0e872037d5a1@arm.com/ Suggested-by: Ryan Roberts Signed-off-by: Steven Rostedt (Google) Reviewed-by: Ryan Roberts Acked-by: Masami Hiramatsu (Google) --- kernel/trace/fgraph.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/trace/fgraph.c b/kernel/trace/fgraph.c index ee829d65f301..51e81b299a0d 100644 --- a/kernel/trace/fgraph.c +++ b/kernel/trace/fgraph.c @@ -153,7 +153,7 @@ enum { * SHADOW_STACK_OFFSET: The size in long words of the shadow stack * SHADOW_STACK_MAX_OFFSET: The max offset of the stack for a new frame to be added */ -#define SHADOW_STACK_SIZE (PAGE_SIZE) +#define SHADOW_STACK_SIZE (4096) #define SHADOW_STACK_OFFSET (SHADOW_STACK_SIZE / sizeof(long)) /* Leave on a buffer at the end */ #define SHADOW_STACK_MAX_OFFSET \