From patchwork Mon Apr 15 12:49:55 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: 13629918 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 85DBB85299; Mon, 15 Apr 2024 12:50:02 +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=1713185402; cv=none; b=rX95gj9BJfdMhIXRU5/wognf5OhuRCxVkbpOnKPNWx7+1V+nEvL5NSq/cbEASjNmifSBSelG1TlLqEBLCfPs3E8glCJbAw1DIm3rbMLIUrmJewBoOqDQCadDWus5lBb2nbs0BjbdjFYPv9IwMRLLvMtgiim8cL+dDqgtHphVIkE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713185402; c=relaxed/simple; bh=v6a8A4n/NQNVvl6IUBlyb4ncY6wKsPnocwxI4QmL7G4=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version:Content-Type; b=aTDZQvubJ6O3igXywurnt12LZiqgqOtiIANsM1z0o+mX/4GDPNmh5EINspQvHLwZreYKp0lxU7DO92qsHPB41OgHf51O73XdC8Xf05z6eo+XqfZoViWosJxE0DQLiVS6IXc5gUIo5O//eZuDhMWEFQWpC64qc+I9Wyi4CfB4fJg= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=mSS8f0tm; 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="mSS8f0tm" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A7837C113CC; Mon, 15 Apr 2024 12:49:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1713185402; bh=v6a8A4n/NQNVvl6IUBlyb4ncY6wKsPnocwxI4QmL7G4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mSS8f0tmbEjB0HOjLht2e8wfg1cZRfKaMcSV9fYdVyQ+xIzbz0p454mUqlXhC4o8h bByVOLS+5HhVbnVNHIS5z5QClB05E7YXYmC6sia/AmRpCXpovgmWUZZb/PToWVdPS+ QC4ssQXovpmYjEGFT4AisJWZPpPE2QVVH5k4jYN8MUtsmm4NG3ZMs7z6DzZ4Ve8Y9b o+FYUI5hlZeAGIjL8uR6AR5TZQRAJZUU42Sl9k+Mj0jatq3Gdy9d059nQzysRGR0ij A74jXL3wU5OPidiEqn2TjYWeCOwGV04GM1bcfHK7ofAhBl2Le23TYGcU8Manj1Szyt m9rc0VCZavMMw== 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 v9 05/36] fgraph: Use BUILD_BUG_ON() to make sure we have structures divisible by long Date: Mon, 15 Apr 2024 21:49:55 +0900 Message-Id: <171318539550.254850.4289354595322910591.stgit@devnote2> X-Mailer: git-send-email 2.34.1 In-Reply-To: <171318533841.254850.15841395205784342850.stgit@devnote2> References: <171318533841.254850.15841395205784342850.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;