From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steven Rostedt Subject: [for-next][PATCH 01/18] function_graph: Create function_graph_enter() to consolidate architecture code Date: Wed, 21 Nov 2018 19:28:02 -0500 Message-ID: <20181122003331.479176746@goodmis.org> References: <20181122002801.501220343@goodmis.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Return-path: Sender: linux-kernel-owner@vger.kernel.org To: linux-kernel@vger.kernel.org Cc: Linus Torvalds , Ingo Molnar , Andrew Morton , Thomas Gleixner , Peter Zijlstra , linux-arch@vger.kernel.org, Joel Fernandes , Masami Hiramatsu , Josh Poimboeuf , Andy Lutomirski , Frederic Weisbecker , stable@kernel.org List-Id: linux-arch.vger.kernel.org From: "Steven Rostedt (VMware)" Currently all the architectures do basically the same thing in preparing the function graph tracer on entry to a function. This code can be pulled into a generic location and then this will allow the function graph tracer to be fixed, as well as extended. Create a new function graph helper function_graph_enter() that will call the hook function (ftrace_graph_entry) and the shadow stack operation (ftrace_push_return_trace), and remove the need of the architecture code to manage the shadow stack. This is needed to prepare for a fix of a design bug on how the curr_ret_stack is used. Cc: stable@kernel.org Fixes: 03274a3ffb449 ("tracing/fgraph: Adjust fgraph depth before calling trace return callback") Signed-off-by: Steven Rostedt (VMware) --- include/linux/ftrace.h | 3 +++ kernel/trace/trace_functions_graph.c | 16 ++++++++++++++++ 2 files changed, 19 insertions(+) diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index a397907e8d72..5717e8f81c59 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -779,6 +779,9 @@ extern void return_to_handler(void); extern int ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth, unsigned long frame_pointer, unsigned long *retp); +extern int +function_graph_enter(unsigned long ret, unsigned long func, + unsigned long frame_pointer, unsigned long *retp); unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx, unsigned long ret, unsigned long *retp); diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c index 169b3c44ee97..28f2602435d0 100644 --- a/kernel/trace/trace_functions_graph.c +++ b/kernel/trace/trace_functions_graph.c @@ -182,6 +182,22 @@ ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth, return 0; } +int function_graph_enter(unsigned long ret, unsigned long func, + unsigned long frame_pointer, unsigned long *retp) +{ + struct ftrace_graph_ent trace; + + trace.func = func; + trace.depth = current->curr_ret_stack + 1; + + /* Only trace if the calling function expects to */ + if (!ftrace_graph_entry(&trace)) + return -EBUSY; + + return ftrace_push_return_trace(ret, func, &trace.depth, + frame_pointer, retp); +} + /* Retrieve a function return address to the trace stack on thread info.*/ static void ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret, -- 2.19.1 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]:47472 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729105AbeKVLKS (ORCPT ); Thu, 22 Nov 2018 06:10:18 -0500 Message-ID: <20181122003331.479176746@goodmis.org> Date: Wed, 21 Nov 2018 19:28:02 -0500 From: Steven Rostedt Subject: [for-next][PATCH 01/18] function_graph: Create function_graph_enter() to consolidate architecture code References: <20181122002801.501220343@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Sender: linux-arch-owner@vger.kernel.org List-ID: To: linux-kernel@vger.kernel.org Cc: Linus Torvalds , Ingo Molnar , Andrew Morton , Thomas Gleixner , Peter Zijlstra , linux-arch@vger.kernel.org, Joel Fernandes , Masami Hiramatsu , Josh Poimboeuf , Andy Lutomirski , Frederic Weisbecker , stable@kernel.org Message-ID: <20181122002802.ad0m_6cJlxTVpzxtpQ0TsVFJZQXL8cKLutsdJGb1MWM@z> From: "Steven Rostedt (VMware)" Currently all the architectures do basically the same thing in preparing the function graph tracer on entry to a function. This code can be pulled into a generic location and then this will allow the function graph tracer to be fixed, as well as extended. Create a new function graph helper function_graph_enter() that will call the hook function (ftrace_graph_entry) and the shadow stack operation (ftrace_push_return_trace), and remove the need of the architecture code to manage the shadow stack. This is needed to prepare for a fix of a design bug on how the curr_ret_stack is used. Cc: stable@kernel.org Fixes: 03274a3ffb449 ("tracing/fgraph: Adjust fgraph depth before calling trace return callback") Signed-off-by: Steven Rostedt (VMware) --- include/linux/ftrace.h | 3 +++ kernel/trace/trace_functions_graph.c | 16 ++++++++++++++++ 2 files changed, 19 insertions(+) diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index a397907e8d72..5717e8f81c59 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -779,6 +779,9 @@ extern void return_to_handler(void); extern int ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth, unsigned long frame_pointer, unsigned long *retp); +extern int +function_graph_enter(unsigned long ret, unsigned long func, + unsigned long frame_pointer, unsigned long *retp); unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx, unsigned long ret, unsigned long *retp); diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c index 169b3c44ee97..28f2602435d0 100644 --- a/kernel/trace/trace_functions_graph.c +++ b/kernel/trace/trace_functions_graph.c @@ -182,6 +182,22 @@ ftrace_push_return_trace(unsigned long ret, unsigned long func, int *depth, return 0; } +int function_graph_enter(unsigned long ret, unsigned long func, + unsigned long frame_pointer, unsigned long *retp) +{ + struct ftrace_graph_ent trace; + + trace.func = func; + trace.depth = current->curr_ret_stack + 1; + + /* Only trace if the calling function expects to */ + if (!ftrace_graph_entry(&trace)) + return -EBUSY; + + return ftrace_push_return_trace(ret, func, &trace.depth, + frame_pointer, retp); +} + /* Retrieve a function return address to the trace stack on thread info.*/ static void ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret, -- 2.19.1