From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932627Ab2HWSRO (ORCPT ); Thu, 23 Aug 2012 14:17:14 -0400 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.122]:6349 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756712Ab2HWSRB (ORCPT ); Thu, 23 Aug 2012 14:17:01 -0400 X-Authority-Analysis: v=2.0 cv=cpwZYiEi c=1 sm=0 a=rXTBtCOcEpjy1lPqhTCpEQ==:17 a=mNMOxpOpBa8A:10 a=Ciwy3NGCPMMA:10 a=83F0lROKfGsA:10 a=5SG0PmZfjMsA:10 a=bbbx4UPp9XUA:10 a=zX0gvU8keR8A:10 a=meVymXHHAAAA:8 a=VwQbUJbxAAAA:8 a=QyXUC8HyAAAA:8 a=WfulkdPnAAAA:8 a=8ssI5vCHBLmoMQwfYCYA:9 a=QEXdDO2ut3YA:10 a=jeBq3FmKZ4MA:10 a=LI9Vle30uBYA:10 a=l29vjEC0CZ8A:10 a=1Wy5nXbt1Apt5BJImcMA:9 a=rXTBtCOcEpjy1lPqhTCpEQ==:117 X-Cloudmark-Score: 0 X-Originating-IP: 74.67.115.198 Message-Id: <20120823181659.584532686@goodmis.org> User-Agent: quilt/0.60-1 Date: Thu, 23 Aug 2012 14:15:40 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , Masami Hiramatsu , Frederic Weisbecker , Thomas Gleixner , "H. Peter Anvin" , "H. Peter Anvin" , Ingo Molnar , Andi Kleen Subject: [PATCH 3/4] ftrace: Do not test frame pointers if -mfentry is used References: <20120823181537.510961094@goodmis.org> Content-Disposition: inline; filename=0003-ftrace-Do-not-test-frame-pointers-if-mfentry-is-used.patch Content-Type: multipart/signed; micalg="pgp-sha1"; protocol="application/pgp-signature"; boundary="00GvhwF7k39YY" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --00GvhwF7k39YY Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable The function graph has a test to check if the frame pointer is corrupted, which can happen with various options of gcc with mcount. But this is not an issue with -mfentry as -mfentry does not need nor use frame pointers for function graph tracing. Link: http://lkml.kernel.org/r/20120807194059.773895870@goodmis.org Acked-by: H. Peter Anvin Acked-by: Ingo Molnar Cc: Andi Kleen Signed-off-by: Steven Rostedt --- kernel/trace/trace_functions_graph.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_func= tions_graph.c index ce27c8b..99b4378 100644 --- a/kernel/trace/trace_functions_graph.c +++ b/kernel/trace/trace_functions_graph.c @@ -143,7 +143,7 @@ ftrace_pop_return_trace(struct ftrace_graph_ret *trace,= unsigned long *ret, return; } =20 -#ifdef CONFIG_HAVE_FUNCTION_GRAPH_FP_TEST +#if defined(CONFIG_HAVE_FUNCTION_GRAPH_FP_TEST) && !defined(CC_USING_FENTR= Y) /* * The arch may choose to record the frame pointer used * and check it here to make sure that it is what we expect it @@ -154,6 +154,9 @@ ftrace_pop_return_trace(struct ftrace_graph_ret *trace,= unsigned long *ret, * * Currently, x86_32 with optimize for size (-Os) makes the latest * gcc do the above. + * + * Note, -mfentry does not use frame pointers, and this test + * is not needed if CC_USING_FENTRY is set. */ if (unlikely(current->ret_stack[index].fp !=3D frame_pointer)) { ftrace_graph_stop(); --=20 1.7.10.4 --00GvhwF7k39YY Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIcBAABAgAGBQJQNnObAAoJEIy3vGnGbaoAGUsP/jxujdjxfWFBihYUSZdb0t6T q+Tj79TrhxMErT4BIbtq0olWTyeRdqB/X0qk+jgkP9CpwUniOHceKHdu3kHoeSyp GOMdRbyWK4J5dIck/6CPcaCo7HPwKxXQDlw2mCypDSgt0GlCzwx++tdb2cIBDljY HD/Lfcnt78LlrLQGbjhvaC2eOBcJaJl8yxQcmZ5hWYkiQyPDXowW4sFU+LCmICh9 hBJkCXRdXsU2KkhFeBj5Gb556u2MboVY2R5T1gVa/x59FtgIgM9kkpoFdsoAuBKc /qfXKPqob/gssLysnqmEb4rwUXcThogw0o2UwBmoLaD+ZYm4ifcwZp1br38xHFXb A9+fyEBDmdbXHpzoFqcHiQmXhtj3MCmW0JnnXOIIG6LO1v2sdoQd754XdXo95/pE /GpzfnoWZRGyzxBWCRNI3QtEtlFK45x6877+0FVRgcxp+6krl5sdlc0uOkXsmuc3 cyjAp0GCtNGrY5GZCDPfn/TkMfp8ZOUFtHsoGyeHSxOFU6tvHUXPYWfKWG5LK7Um 42qLIW0xCJFN3iNBIRdxrCAYUgudO9uandScSlu36ylji42PbY9GY/KJZXWpywsy JiifHa78tttph6abHyq1LaTwXOBHwtnGKVdi4Ay/l+MufYwkZo2zVmfj8hmGNU+f RrRu+ZiNJFJWTaxBsCe6 =uDdk -----END PGP SIGNATURE----- --00GvhwF7k39YY--