From patchwork Wed Nov 8 14:25:18 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 13450151 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 D62D810A15; Wed, 8 Nov 2023 14:25:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Acy4qeR6" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C151CC433C7; Wed, 8 Nov 2023 14:25:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1699453524; bh=BJTb9S/48BMXgKg9JdebJFjIf4uCQaHDkO4DGbu+/d0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Acy4qeR6BmcEQIGzPtHgOgB0gKQWzzYs3q3oYarlZc076haMeyyfEC9YzRmimIDDw yChtK1EyyMO6JJfs7T5C5Xd/g8i5c+LZbJ8fGQSEh2ueMA5xbuTdT+8Q1usaEPA30/ G7/8A+L1F+jJhYu00RzU545pcHZRXIyNPk5TXUYTlkHq1wIU+E1nBN1RcppKb+Xv2K DbVJnnTZSm+IYeZ9ma/6stb7jIlu0aPS6dBQnRRSkmDZ0z9PYwYumtdzCNQfJWNRCb KQvpIIGZqeK8rfyHkvBoYageUDVVhi9f0hf1CZYG6ZKZUza1IK1VJIc58YW20EqeRU 2NUTsAG4iorNQ== 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: [RFC PATCH v2 05/31] fgraph: Use BUILD_BUG_ON() to make sure we have structures divisible by long Date: Wed, 8 Nov 2023 23:25:18 +0900 Message-Id: <169945351784.55307.8993860437930966865.stgit@devnote2> X-Mailer: git-send-email 2.34.1 In-Reply-To: <169945345785.55307.5003201137843449313.stgit@devnote2> References: <169945345785.55307.5003201137843449313.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 X-Patchwork-State: RFC 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) --- 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..837daf929d2a 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 (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;