[PATCH 2/6] oprofile/x86: add regs->ip to oprofile trace

From: Josh Poimboeuf <jpoimboe@redhat.com>
To: Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@kernel.org>, "H . Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org, linux-kernel@vger.kernel.org,
	Andy Lutomirski <luto@amacapital.net>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Steven Rostedt <rostedt@goodmis.org>,
	Brian Gerst <brgerst@gmail.com>,
	Kees Cook <keescook@chromium.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Frederic Weisbecker <fweisbec@gmail.com>,
	Byungchul Park <byungchul.park@lge.com>,
	Nilay Vaish <nilayvaish@gmail.com>,
	Robert Richter <rric@kernel.org>
Subject: [PATCH 2/6] oprofile/x86: add regs->ip to oprofile trace
Date: Wed, 24 Aug 2016 11:50:15 -0500	[thread overview]
Message-ID: <6c745a83dbd69fc6857ef9b2f8be0f011d775936.1472057064.git.jpoimboe@redhat.com> (raw)
In-Reply-To: <cover.1472057064.git.jpoimboe@redhat.com>

dump_trace() doesn't add the interrupted instruction's address to the
trace, so add it manually.  This makes the profile more useful, and also
makes it more consistent with what perf profiling does.

Cc: Robert Richter <rric@kernel.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
---
 arch/x86/oprofile/backtrace.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/arch/x86/oprofile/backtrace.c b/arch/x86/oprofile/backtrace.c
index cb31a44..2ef6c8b 100644
--- a/arch/x86/oprofile/backtrace.c
+++ b/arch/x86/oprofile/backtrace.c
@@ -114,9 +114,16 @@ x86_backtrace(struct pt_regs * const regs, unsigned int depth)
 
 	if (!user_mode(regs)) {
 		unsigned long stack = kernel_stack_pointer(regs);
-		if (depth)
-			dump_trace(NULL, regs, (unsigned long *)stack, 0,
-				   &backtrace_ops, &depth);
+
+		if (!depth)
+			return;
+
+		oprofile_add_trace(regs->ip);
+		if (!--depth)
+			return;
+
+		dump_trace(NULL, regs, (unsigned long *)stack, 0,
+			   &backtrace_ops, &depth);
 		return;
 	}
 
-- 
2.7.4
