From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754805Ab2IHL5x (ORCPT ); Sat, 8 Sep 2012 07:57:53 -0400 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.122]:10456 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754474Ab2IHL4n (ORCPT ); Sat, 8 Sep 2012 07:56:43 -0400 X-Authority-Analysis: v=2.0 cv=Vb91zSV9 c=1 sm=0 a=rXTBtCOcEpjy1lPqhTCpEQ==:17 a=mNMOxpOpBa8A:10 a=Ciwy3NGCPMMA:10 a=toKkhtHTqdEA:10 a=5SG0PmZfjMsA:10 a=bbbx4UPp9XUA:10 a=meVymXHHAAAA:8 a=h6bqgZrG79wA:10 a=VwQbUJbxAAAA:8 a=pGLkceISAAAA:8 a=oGMlB6cnAAAA:8 a=3nbZYyFuAAAA:8 a=Qq8FTLfLWGNYfXvcnDEA:9 a=QEXdDO2ut3YA:10 a=MSl-tDqOz04A:10 a=Zh68SRI7RUMA:10 a=CY6gl2JlH4YA:10 a=EvKJbDF4Ut8A:10 a=jeBq3FmKZ4MA:10 a=rGYwZ7Sk61uqzLHj80UA:9 a=rXTBtCOcEpjy1lPqhTCpEQ==:117 X-Cloudmark-Score: 0 X-Originating-IP: 74.67.115.198 Message-Id: <20120908115641.031808366@goodmis.org> User-Agent: quilt/0.60-1 Date: Sat, 08 Sep 2012 07:55:20 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , Peter Zijlstra , Frederic Weisbecker , Thomas Gleixner , "H. Peter Anvin" , Masami Hiramatsu Subject: [PATCH 5/7] kprobes/x86: Fix kprobes to collectly handle IP on ftrace References: <20120908115515.211175517@goodmis.org> Content-Disposition: inline; filename=0005-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 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) iQIcBAABAgAGBQJQSzJ5AAoJEIy3vGnGbaoALLoP/iek64w9JL5x3hfw6/npHWkQ DH2nJJKjwsuQmg0bmNXPVNwTLgz+trTtvMXBEYxf7KM1knN/033YzGNdeuDrzqHl 8bVdKvS90G0zFGznYn7dRr1sgblJPCaPgnkiDIvVhnFS+FfXSO2LDKkHFLGgBOJn TqM4S/4ZY6j6g9w29V8LDOsLtokxsOlREAqaFdGS2/GZaii6B+O0L7XYfjGyvJeK LsUJ3qBOdL/YzGVHHsacAeIUx2a8S8+Q5cfmieq+EhQNTjcJFFGWsmX4iKVBBjEE 9kD5HBYkUQTmFRoOf27xx01S0AmUMmLPUVC1ZzI8tCRapA8Qt8H/xhhuvYGjcD5Y N8Sez/ob27zZobJfqe6WEbZEt0xG3XC2gPI3r8uNq2Yl8/4sYLbsEENhagcFk9N/ ak1MhzMv+tFWE5VEqMYBC6SA1npsoN+AJ0RbUozVoJv+QkfLBbxdklrGI5WD6i1a 26HgRtNnmCVLFuuDZSnAXb6Qm+qdvdOvzVO6pKRXrcNgayaNGtHNWWAMzOleD5JW EvWjqVNgXpjJPvy7+gV4AKJtlEa7fqnrCM6CNlx+ZAuTSLbMuHu2+5ml9lfvn4Bv /wZR6lK7RqUTlEvDdQIVq7QisiVrsfj/4/06V6fAfiv5mFo5h4DI7XfyeJyHRU1w fNzNMrJzMyya8hrG2upe =fnGt -----END PGP SIGNATURE----- --00GvhwF7k39YY--