From patchwork Tue Feb 6 15:08:36 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 13547437 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 819CE134CC2; Tue, 6 Feb 2024 15:08:42 +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=1707232122; cv=none; b=g7IOv0L98FYjR93FZS7NdLHeWHoOnK5irUzvrPoX4rxiZ3lgtp3pJPwaKecuyA/WcvBclx15QlyBXXmej18HbswFf98zYRk8E++Z+LhncNwyCqzPtJFl/diJP/Yar0N5fLraSTTZChshfg3pex7s9yDEM9jmhgXq9ci19H0FGn4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707232122; c=relaxed/simple; bh=v6a8A4n/NQNVvl6IUBlyb4ncY6wKsPnocwxI4QmL7G4=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version:Content-Type; b=RxYrAgHFY/XMTShB4tEbeYzU5CCJqiRfSElOu7FEficjBzOUaSOcnRW1kITOo6Hg8BWW+4FGAIBdW4ca1q/a7hXYf+1iVhjJbj3H7pn9Yeq5E3jGIMb5axo40tE1EJTw4G9NgeCyPbFJ+Sqk3eVqkODon3fHgdURsIeITw3emk4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=MQnVhub6; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="MQnVhub6" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9719CC43390; Tue, 6 Feb 2024 15:08:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1707232122; bh=v6a8A4n/NQNVvl6IUBlyb4ncY6wKsPnocwxI4QmL7G4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=MQnVhub6V+x9VzaS4J+qqX7sfnUSbbornWCaLcO3hsFS+ImOvdng9znvsrF0imNj2 A4VKH1ng2FtNeyUZxdr822jTEUVpGZUQQfzbgMA5A8G+qJNI356PCOTZAn7wLasmub h4gGripv/GYAmh1BJrnI9JTIARJQZ9XwBx6Z3GCZf8eBxHnk1voVrESy+g6Y8Vqvdg pQe1DGQEi2UAaOKC4z4Hzsw5Ob72m2R8dTNqqlEfwKHea11gbf5hM5iArPtJKK+vfX 9kvl2G0FyEUVJYUjKRDEdBQ2a1fenhSY79OpQcp6kQUXLMlZBiRmjGUi6ztJ9xmlKd SQ30nxW1lKKqw== From: "Masami Hiramatsu (Google)" To: Alexei Starovoitov , Steven Rostedt , Florent Revest Cc: linux-trace-kernel@vger.kernel.org, LKML , Martin KaFai Lau , bpf , Sven Schnelle , Alexei Starovoitov , Jiri Olsa , Arnaldo Carvalho de Melo , Daniel Borkmann , Alan Maguire , Mark Rutland , Peter Zijlstra , Thomas Gleixner , Guo Ren Subject: [PATCH v7 06/36] fgraph: Use BUILD_BUG_ON() to make sure we have structures divisible by long Date: Wed, 7 Feb 2024 00:08:36 +0900 Message-Id: <170723211649.502590.2604541564082439754.stgit@devnote2> X-Mailer: git-send-email 2.34.1 In-Reply-To: <170723204881.502590.11906735097521170661.stgit@devnote2> References: <170723204881.502590.11906735097521170661.stgit@devnote2> User-Agent: StGit/0.19 Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Steven Rostedt (VMware) Instead of using "ALIGN()", use BUILD_BUG_ON() as the structures should always be divisible by sizeof(long). Link: http://lkml.kernel.org/r/20190524111144.GI2589@hirez.programming.kicks-ass.net Suggested-by: Peter Zijlstra Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Masami Hiramatsu (Google) --- Changes in v7: - Use DIV_ROUND_UP() to calculate FGRAPH_RET_INDEX --- kernel/trace/fgraph.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/kernel/trace/fgraph.c b/kernel/trace/fgraph.c index 30edeb6d4aa9..6f8d36370994 100644 --- a/kernel/trace/fgraph.c +++ b/kernel/trace/fgraph.c @@ -26,10 +26,9 @@ #endif #define FGRAPH_RET_SIZE sizeof(struct ftrace_ret_stack) -#define FGRAPH_RET_INDEX (ALIGN(FGRAPH_RET_SIZE, sizeof(long)) / sizeof(long)) +#define FGRAPH_RET_INDEX DIV_ROUND_UP(FGRAPH_RET_SIZE, sizeof(long)) #define SHADOW_STACK_SIZE (PAGE_SIZE) -#define SHADOW_STACK_INDEX \ - (ALIGN(SHADOW_STACK_SIZE, sizeof(long)) / sizeof(long)) +#define SHADOW_STACK_INDEX (SHADOW_STACK_SIZE / sizeof(long)) /* Leave on a buffer at the end */ #define SHADOW_STACK_MAX_INDEX (SHADOW_STACK_INDEX - FGRAPH_RET_INDEX) @@ -91,6 +90,8 @@ ftrace_push_return_trace(unsigned long ret, unsigned long func, if (!current->ret_stack) return -EBUSY; + BUILD_BUG_ON(SHADOW_STACK_SIZE % sizeof(long)); + /* * We must make sure the ret_stack is tested before we read * anything else. @@ -325,6 +326,8 @@ ftrace_graph_get_ret_stack(struct task_struct *task, int idx) { int index = task->curr_ret_stack; + BUILD_BUG_ON(FGRAPH_RET_SIZE % sizeof(long)); + index -= FGRAPH_RET_INDEX * (idx + 1); if (index < 0) return NULL;