From patchwork Sun Feb 25 15:15:58 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: 13570848 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 891DE17584; Sun, 25 Feb 2024 15:16:04 +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=1708874164; cv=none; b=pb109QV1tYtWFI1ErtA4epAIOjspzui8m3s3GTy+O7cN5QEtmWxMxR939iRrWOBTuNucq5r1EQ2lFl++iDn8/GPh2BSf1w5GHH3cyY9cZXKb/xQPEXJizCgi0+R/vJIcWrw2KP2m9tfV17XFZaOAVXMOYlE/D9CwaXHBzfN50Gk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708874164; c=relaxed/simple; bh=v6a8A4n/NQNVvl6IUBlyb4ncY6wKsPnocwxI4QmL7G4=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version:Content-Type; b=BakN5gHCdH485uw53Hf889SP5IP75ehbF0pgg8GfpZ4N59DusrxcRxyjwcH/cwroks/LnNi0Ik30PMJAqbYamb/0eYOKQ8/GpUvpHSjn8LXvhoctECdTDE4iO6TAN06FylLWMhCaqUY5+xB+LBmRcvFlcZ3+tUQW+VIzAIef7zs= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=QXUre6XP; 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="QXUre6XP" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0A726C433F1; Sun, 25 Feb 2024 15:16:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1708874164; bh=v6a8A4n/NQNVvl6IUBlyb4ncY6wKsPnocwxI4QmL7G4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QXUre6XPnI81EY0m3S3EOLP0frJIY/XLwk1o9zu85FqVubANhpGRLbP+8LRtkUDA3 B+T+WELA9Im4wzVxFk8D21LxfwC4B4F0Ybvb+ETT+TZTpkfGjpnprUXJ0CC7kayJCX 0PnG/4q3ekl+BV9uxRlRM7h/8LyNOWb3DXg+AO1guxRQFzhfiDaFvBN6HlLVpodj+p swiKCvcV0NrAREvMEFAw9pod8guQZcnFMtes3sQhHBie/1zhj+64wp02iY//KCYa0A 2/dpUORGigM4M786knB2FshNDe9peTwwQxBWqpV2QVVMOhKVdl8sggwMZRXO8ZwttJ nF7OCM1eMMuQw== 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 v8 05/35] fgraph: Use BUILD_BUG_ON() to make sure we have structures divisible by long Date: Mon, 26 Feb 2024 00:15:58 +0900 Message-Id: <170887415852.564249.2786094184227554396.stgit@devnote2> X-Mailer: git-send-email 2.34.1 In-Reply-To: <170887410337.564249.6360118840946697039.stgit@devnote2> References: <170887410337.564249.6360118840946697039.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;