From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756582Ab2INDDg (ORCPT ); Thu, 13 Sep 2012 23:03:36 -0400 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.122]:29837 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754454Ab2INDCf (ORCPT ); Thu, 13 Sep 2012 23:02:35 -0400 X-Authority-Analysis: v=2.0 cv=VPlfbqzX c=1 sm=0 a=rXTBtCOcEpjy1lPqhTCpEQ==:17 a=mNMOxpOpBa8A:10 a=Ciwy3NGCPMMA:10 a=mAZSS0CqBOAA:10 a=5SG0PmZfjMsA:10 a=bbbx4UPp9XUA:10 a=meVymXHHAAAA:8 a=3d-f-Oou5mwA:10 a=3nbZYyFuAAAA:8 a=VwQbUJbxAAAA:8 a=pGLkceISAAAA:8 a=oGMlB6cnAAAA:8 a=Qq8FTLfLWGNYfXvcnDEA:9 a=QEXdDO2ut3YA:10 a=EvKJbDF4Ut8A:10 a=MSl-tDqOz04A:10 a=Zh68SRI7RUMA:10 a=CY6gl2JlH4YA:10 a=jeBq3FmKZ4MA:10 a=5Q2DmOMaCtWOoRoQ8tsA:9 a=rXTBtCOcEpjy1lPqhTCpEQ==:117 X-Cloudmark-Score: 0 X-Originating-IP: 74.67.115.198 Message-Id: <20120914030232.685276785@goodmis.org> User-Agent: quilt/0.60-1 Date: Thu, 13 Sep 2012 23:00:16 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , Frederic Weisbecker , Peter Zijlstra , Thomas Gleixner , "H. Peter Anvin" , Masami Hiramatsu Subject: [PATCH 4/6 v2] kprobes/x86: Fix kprobes to collectly handle IP on ftrace References: <20120914030012.315074731@goodmis.org> Content-Disposition: inline; filename=0004-kprobes-x86-Fix-kprobes-to-collectly-handle-IP-on-ft.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 From: Masami Hiramatsu Current kprobe_ftrace_handler expects regs->ip =3D=3D ip, but it is incorrect (originally on x86-64). Actually, ftrace handler sets regs->ip =3D ip + MCOUNT_INSN_SIZE. kprobe_ftrace_handler must take care for that. Link: http://lkml.kernel.org/r/20120905143112.10329.72069.stgit@localhost.l= ocaldomain Cc: Peter Zijlstra Cc: Frederic Weisbecker Cc: Thomas Gleixner Cc: "H. Peter Anvin" Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt --- arch/x86/kernel/kprobes.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/arch/x86/kernel/kprobes.c b/arch/x86/kernel/kprobes.c index 47ae102..f49f60c 100644 --- a/arch/x86/kernel/kprobes.c +++ b/arch/x86/kernel/kprobes.c @@ -1072,7 +1072,8 @@ void __kprobes kprobe_ftrace_handler(unsigned long ip= , unsigned long parent_ip, if (kprobe_running()) { kprobes_inc_nmissed_count(p); } else { - regs->ip +=3D sizeof(kprobe_opcode_t); + /* Kprobe handler expects regs->ip =3D ip + 1 as breakpoint hit */ + regs->ip =3D ip + sizeof(kprobe_opcode_t); =20 __this_cpu_write(current_kprobe, p); kcb->kprobe_status =3D KPROBE_HIT_ACTIVE; @@ -1080,13 +1081,15 @@ void __kprobes kprobe_ftrace_handler(unsigned long = ip, unsigned long parent_ip, p->pre_handler(p, regs); =20 if (unlikely(p->post_handler)) { - /* Emulate singlestep as if there is a 5byte nop */ + /* + * Emulate singlestep (and also recover regs->ip) + * as if there is a 5byte nop + */ regs->ip =3D ip + MCOUNT_INSN_SIZE; kcb->kprobe_status =3D KPROBE_HIT_SSDONE; p->post_handler(p, regs, 0); } __this_cpu_write(current_kprobe, NULL); - regs->ip =3D ip; /* Recover for next callback */ } end: local_irq_restore(flags); --=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) iQEcBAABAgAGBQJQUp5IAAoJEOdOSU1xswtMcZgH+wShqFoS217zWkTcDY9DW2/5 jQWM5AOM0/CpM/iUFBWneyuOhxe8d5Z0yEYtKqe2hKNQKzqkaKSuwYA1TpW5uanp gGJo9oZKbU+StaIG34asWRUgAUGQWuUu2Q77OLBnE6hGtTl6f+Siyhe8pkejltFg cw697e3q95yzCKXzG7Wb4p9ndhZkqkR0Hn6/G8GPFmim9WoFcj5CZq1Mk5BtKXbV BCnObtLip2wB6dl2qa2tp1hH7XiE1XxkU5WJVOwqVM3LAsqYLWt1A97wlTaq9Q5m PiFBrvpHH530m3p5DCvh5kUtOLrX1X8vdlsp9bZY27+FoejvRBRb3VXvwSAfKW4= =lo3I -----END PGP SIGNATURE----- --00GvhwF7k39YY--