linux-kernel - [PATCH 4.19 099/139] ARM: function_graph: Simplify with function_graph

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20181204103654.523899144@linuxfoundation.org>
Date:   Tue,  4 Dec 2018 11:49:40 +0100
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Russell King <linux@...linux.org.uk>,
        linux-arm-kernel@...ts.infradead.org, stable@...nel.org,
        Masami Hiramatsu <mhiramat@...nel.org>,
        "Steven Rostedt (VMware)" <rostedt@...dmis.org>
Subject: [PATCH 4.19 099/139] ARM: function_graph: Simplify with function_graph_enter()

4.19-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Steven Rostedt (VMware) <rostedt@...dmis.org>

commit f1f5b14afd7cce39e6a9b25c685e1ea34c231096 upstream.

The function_graph_enter() function does the work of calling the function
graph hook function and the management of the shadow stack, simplifying the
work done in the architecture dependent prepare_ftrace_return().

Have ARM use the new code, and remove the shadow stack management as well as
having to set up the trace structure.

This is needed to prepare for a fix of a design bug on how the curr_ret_stack
is used.

Cc: Russell King <linux@...linux.org.uk>
Cc: linux-arm-kernel@...ts.infradead.org
Cc: stable@...nel.org
Fixes: 03274a3ffb449 ("tracing/fgraph: Adjust fgraph depth before calling trace return callback")
Reviewed-by: Masami Hiramatsu <mhiramat@...nel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@...dmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 arch/arm/kernel/ftrace.c |   17 +----------------
 1 file changed, 1 insertion(+), 16 deletions(-)

--- a/arch/arm/kernel/ftrace.c
+++ b/arch/arm/kernel/ftrace.c
@@ -227,9 +227,7 @@ void prepare_ftrace_return(unsigned long
 			   unsigned long frame_pointer)
 {
 	unsigned long return_hooker = (unsigned long) &return_to_handler;
-	struct ftrace_graph_ent trace;
 	unsigned long old;
-	int err;
 
 	if (unlikely(atomic_read(&current->tracing_graph_pause)))
 		return;
@@ -237,21 +235,8 @@ void prepare_ftrace_return(unsigned long
 	old = *parent;
 	*parent = return_hooker;
 
-	trace.func = self_addr;
-	trace.depth = current->curr_ret_stack + 1;
-
-	/* Only trace if the calling function expects to */
-	if (!ftrace_graph_entry(&trace)) {
+	if (function_graph_enter(old, self_addr, frame_pointer, NULL))
 		*parent = old;
-		return;
-	}
-
-	err = ftrace_push_return_trace(old, self_addr, &trace.depth,
-				       frame_pointer, NULL);
-	if (err == -EBUSY) {
-		*parent = old;
-		return;
-	}
 }
 
 #ifdef CONFIG_DYNAMIC_FTRACE