[PATCH 1/6] perf/x86: check perf_callchain_store() error

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>
Subject: [PATCH 1/6] perf/x86: check perf_callchain_store() error
Date: Wed, 24 Aug 2016 11:50:14 -0500	[thread overview]
Message-ID: <dce6d60bab08be2600efd90021d9b85620646161.1472057064.git.jpoimboe@redhat.com> (raw)
In-Reply-To: <cover.1472057064.git.jpoimboe@redhat.com>

Add a check to perf_callchain_kernel() so that it returns early if the
callchain entry array is already full.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
---
 arch/x86/events/core.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c
index 18a1acf..dcaa887 100644
--- a/arch/x86/events/core.c
+++ b/arch/x86/events/core.c
@@ -2297,7 +2297,8 @@ perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, struct pt_regs *re
 		return;
 	}
 
-	perf_callchain_store(entry, regs->ip);
+	if (perf_callchain_store(entry, regs->ip))
+		return;
 
 	dump_trace(NULL, regs, NULL, 0, &backtrace_ops, entry);
 }
-- 
2.7.4
