From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CB2A1C55179 for ; Fri, 6 Nov 2020 02:35:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 773BD2083B for ; Fri, 6 Nov 2020 02:35:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725933AbgKFCfu (ORCPT ); Thu, 5 Nov 2020 21:35:50 -0500 Received: from mail.kernel.org ([198.145.29.99]:40840 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725849AbgKFCfu (ORCPT ); Thu, 5 Nov 2020 21:35:50 -0500 Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 7BDCC22227; Fri, 6 Nov 2020 02:35:48 +0000 (UTC) Received: from rostedt by gandalf.local.home with local (Exim 4.94) (envelope-from ) id 1karbP-007WLH-2p; Thu, 05 Nov 2020 21:35:47 -0500 Message-ID: <20201106023546.944907560@goodmis.org> User-Agent: quilt/0.66 Date: Thu, 05 Nov 2020 21:32:40 -0500 From: Steven Rostedt (VMware) To: linux-kernel@vger.kernel.org Cc: Masami Hiramatsu , Andrew Morton , Peter Zijlstra , Ingo Molnar , Josh Poimboeuf , Jiri Kosina , Miroslav Benes , Petr Mladek , Guo Ren , "James E.J. Bottomley" , Helge Deller , Michael Ellerman , Benjamin Herrenschmidt , Paul Mackerras , Heiko Carstens , Vasily Gorbik , Christian Borntraeger , Thomas Gleixner , Borislav Petkov , x86@kernel.org, "H. Peter Anvin" , "Naveen N. Rao" , Anil S Keshavamurthy , "David S. Miller" , linux-csky@vger.kernel.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org Subject: [PATCH 05/11 v3] kprobes/ftrace: Add recursion protection to the ftrace callback References: <20201106023235.367190737@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Precedence: bulk List-ID: X-Mailing-List: linux-parisc@vger.kernel.org From: "Steven Rostedt (VMware)" If a ftrace callback does not supply its own recursion protection and does not set the RECURSION_SAFE flag in its ftrace_ops, then ftrace will make a helper trampoline to do so before calling the callback instead of just calling the callback directly. The default for ftrace_ops is going to change. It will expect that handlers provide their own recursion protection, unless its ftrace_ops states otherwise. Link: https://lkml.kernel.org/r/20201028115613.140212174@goodmis.org Cc: Andrew Morton Cc: Masami Hiramatsu Cc: Guo Ren Cc: "James E.J. Bottomley" Cc: Helge Deller Cc: Michael Ellerman Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Heiko Carstens Cc: Vasily Gorbik Cc: Christian Borntraeger Cc: Thomas Gleixner Cc: Borislav Petkov Cc: x86@kernel.org Cc: "H. Peter Anvin" Cc: "Naveen N. Rao" Cc: Anil S Keshavamurthy Cc: "David S. Miller" Cc: linux-csky@vger.kernel.org Cc: linux-parisc@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Signed-off-by: Steven Rostedt (VMware) --- Changes since v2: - Move get_kprobe() into preempt disabled sections for various archs arch/csky/kernel/probes/ftrace.c | 12 ++++++++++-- arch/parisc/kernel/ftrace.c | 16 +++++++++++++--- arch/powerpc/kernel/kprobes-ftrace.c | 11 ++++++++++- arch/s390/kernel/ftrace.c | 16 +++++++++++++--- arch/x86/kernel/kprobes/ftrace.c | 12 ++++++++++-- 5 files changed, 56 insertions(+), 11 deletions(-) diff --git a/arch/csky/kernel/probes/ftrace.c b/arch/csky/kernel/probes/ftrace.c index 5264763d05be..5eb2604fdf71 100644 --- a/arch/csky/kernel/probes/ftrace.c +++ b/arch/csky/kernel/probes/ftrace.c @@ -13,16 +13,21 @@ int arch_check_ftrace_location(struct kprobe *p) void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip, struct ftrace_ops *ops, struct pt_regs *regs) { + int bit; bool lr_saver = false; struct kprobe *p; struct kprobe_ctlblk *kcb; - /* Preempt is disabled by ftrace */ + bit = ftrace_test_recursion_trylock(); + if (bit < 0) + return; + + preempt_disable_notrace(); p = get_kprobe((kprobe_opcode_t *)ip); if (!p) { p = get_kprobe((kprobe_opcode_t *)(ip - MCOUNT_INSN_SIZE)); if (unlikely(!p) || kprobe_disabled(p)) - return; + goto out; lr_saver = true; } @@ -56,6 +61,9 @@ void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip, */ __this_cpu_write(current_kprobe, NULL); } +out: + preempt_enable_notrace(); + ftrace_test_recursion_unlock(bit); } NOKPROBE_SYMBOL(kprobe_ftrace_handler); diff --git a/arch/parisc/kernel/ftrace.c b/arch/parisc/kernel/ftrace.c index 63e3ecb9da81..13d85042810a 100644 --- a/arch/parisc/kernel/ftrace.c +++ b/arch/parisc/kernel/ftrace.c @@ -207,14 +207,21 @@ void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip, struct ftrace_ops *ops, struct pt_regs *regs) { struct kprobe_ctlblk *kcb; - struct kprobe *p = get_kprobe((kprobe_opcode_t *)ip); + struct kprobe *p; + int bit; - if (unlikely(!p) || kprobe_disabled(p)) + bit = ftrace_test_recursion_trylock(); + if (bit < 0) return; + preempt_disable_notrace(); + p = get_kprobe((kprobe_opcode_t *)ip); + if (unlikely(!p) || kprobe_disabled(p)) + goto out; + if (kprobe_running()) { kprobes_inc_nmissed_count(p); - return; + goto out; } __this_cpu_write(current_kprobe, p); @@ -235,6 +242,9 @@ void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip, } } __this_cpu_write(current_kprobe, NULL); +out: + preempt_enable_notrace(); + ftrace_test_recursion_unlock(bit); } NOKPROBE_SYMBOL(kprobe_ftrace_handler); diff --git a/arch/powerpc/kernel/kprobes-ftrace.c b/arch/powerpc/kernel/kprobes-ftrace.c index 972cb28174b2..5df8d50c65ae 100644 --- a/arch/powerpc/kernel/kprobes-ftrace.c +++ b/arch/powerpc/kernel/kprobes-ftrace.c @@ -18,10 +18,16 @@ void kprobe_ftrace_handler(unsigned long nip, unsigned long parent_nip, { struct kprobe *p; struct kprobe_ctlblk *kcb; + int bit; + bit = ftrace_test_recursion_trylock(); + if (bit < 0) + return; + + preempt_disable_notrace(); p = get_kprobe((kprobe_opcode_t *)nip); if (unlikely(!p) || kprobe_disabled(p)) - return; + goto out; kcb = get_kprobe_ctlblk(); if (kprobe_running()) { @@ -52,6 +58,9 @@ void kprobe_ftrace_handler(unsigned long nip, unsigned long parent_nip, */ __this_cpu_write(current_kprobe, NULL); } +out: + preempt_enable_notrace(); + ftrace_test_recursion_unlock(bit); } NOKPROBE_SYMBOL(kprobe_ftrace_handler); diff --git a/arch/s390/kernel/ftrace.c b/arch/s390/kernel/ftrace.c index b388e87a08bf..8f31c726537a 100644 --- a/arch/s390/kernel/ftrace.c +++ b/arch/s390/kernel/ftrace.c @@ -201,14 +201,21 @@ void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip, struct ftrace_ops *ops, struct pt_regs *regs) { struct kprobe_ctlblk *kcb; - struct kprobe *p = get_kprobe((kprobe_opcode_t *)ip); + struct kprobe *p; + int bit; - if (unlikely(!p) || kprobe_disabled(p)) + bit = ftrace_test_recursion_trylock(); + if (bit < 0) return; + preempt_disable_notrace(); + p = get_kprobe((kprobe_opcode_t *)ip); + if (unlikely(!p) || kprobe_disabled(p)) + goto out; + if (kprobe_running()) { kprobes_inc_nmissed_count(p); - return; + goto out; } __this_cpu_write(current_kprobe, p); @@ -228,6 +235,9 @@ void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip, } } __this_cpu_write(current_kprobe, NULL); +out: + preempt_enable_notrace(); + ftrace_test_recursion_unlock(bit); } NOKPROBE_SYMBOL(kprobe_ftrace_handler); diff --git a/arch/x86/kernel/kprobes/ftrace.c b/arch/x86/kernel/kprobes/ftrace.c index 681a4b36e9bb..a40a6cdfcca3 100644 --- a/arch/x86/kernel/kprobes/ftrace.c +++ b/arch/x86/kernel/kprobes/ftrace.c @@ -18,11 +18,16 @@ void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip, { struct kprobe *p; struct kprobe_ctlblk *kcb; + int bit; - /* Preempt is disabled by ftrace */ + bit = ftrace_test_recursion_trylock(); + if (bit < 0) + return; + + preempt_disable_notrace(); p = get_kprobe((kprobe_opcode_t *)ip); if (unlikely(!p) || kprobe_disabled(p)) - return; + goto out; kcb = get_kprobe_ctlblk(); if (kprobe_running()) { @@ -52,6 +57,9 @@ void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip, */ __this_cpu_write(current_kprobe, NULL); } +out: + preempt_enable_notrace(); + ftrace_test_recursion_unlock(bit); } NOKPROBE_SYMBOL(kprobe_ftrace_handler); -- 2.28.0 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 22036C388F7 for ; Fri, 6 Nov 2020 02:38:00 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id D1C0920786 for ; 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Fri, 6 Nov 2020 13:35:51 +1100 (AEDT) Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 7BDCC22227; Fri, 6 Nov 2020 02:35:48 +0000 (UTC) Received: from rostedt by gandalf.local.home with local (Exim 4.94) (envelope-from ) id 1karbP-007WLH-2p; Thu, 05 Nov 2020 21:35:47 -0500 Message-ID: <20201106023546.944907560@goodmis.org> User-Agent: quilt/0.66 Date: Thu, 05 Nov 2020 21:32:40 -0500 From: Steven Rostedt (VMware) To: linux-kernel@vger.kernel.org Subject: [PATCH 05/11 v3] kprobes/ftrace: Add recursion protection to the ftrace callback References: <20201106023235.367190737@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Peter Zijlstra , "James E.J. Bottomley" , Guo Ren , linux-csky@vger.kernel.org, "H. Peter Anvin" , Miroslav Benes , Ingo Molnar , linux-s390@vger.kernel.org, Helge Deller , x86@kernel.org, Anil S Keshavamurthy , Christian Borntraeger , "Naveen N. Rao" , Petr Mladek , Vasily Gorbik , Heiko Carstens , Jiri Kosina , Borislav Petkov , Josh Poimboeuf , Thomas Gleixner , linux-parisc@vger.kernel.org, Masami Hiramatsu , Paul Mackerras , Andrew Morton , linuxppc-dev@lists.ozlabs.org, "David S. Miller" Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" From: "Steven Rostedt (VMware)" If a ftrace callback does not supply its own recursion protection and does not set the RECURSION_SAFE flag in its ftrace_ops, then ftrace will make a helper trampoline to do so before calling the callback instead of just calling the callback directly. The default for ftrace_ops is going to change. It will expect that handlers provide their own recursion protection, unless its ftrace_ops states otherwise. Link: https://lkml.kernel.org/r/20201028115613.140212174@goodmis.org Cc: Andrew Morton Cc: Masami Hiramatsu Cc: Guo Ren Cc: "James E.J. Bottomley" Cc: Helge Deller Cc: Michael Ellerman Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Heiko Carstens Cc: Vasily Gorbik Cc: Christian Borntraeger Cc: Thomas Gleixner Cc: Borislav Petkov Cc: x86@kernel.org Cc: "H. Peter Anvin" Cc: "Naveen N. Rao" Cc: Anil S Keshavamurthy Cc: "David S. Miller" Cc: linux-csky@vger.kernel.org Cc: linux-parisc@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-s390@vger.kernel.org Signed-off-by: Steven Rostedt (VMware) --- Changes since v2: - Move get_kprobe() into preempt disabled sections for various archs arch/csky/kernel/probes/ftrace.c | 12 ++++++++++-- arch/parisc/kernel/ftrace.c | 16 +++++++++++++--- arch/powerpc/kernel/kprobes-ftrace.c | 11 ++++++++++- arch/s390/kernel/ftrace.c | 16 +++++++++++++--- arch/x86/kernel/kprobes/ftrace.c | 12 ++++++++++-- 5 files changed, 56 insertions(+), 11 deletions(-) diff --git a/arch/csky/kernel/probes/ftrace.c b/arch/csky/kernel/probes/ftrace.c index 5264763d05be..5eb2604fdf71 100644 --- a/arch/csky/kernel/probes/ftrace.c +++ b/arch/csky/kernel/probes/ftrace.c @@ -13,16 +13,21 @@ int arch_check_ftrace_location(struct kprobe *p) void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip, struct ftrace_ops *ops, struct pt_regs *regs) { + int bit; bool lr_saver = false; struct kprobe *p; struct kprobe_ctlblk *kcb; - /* Preempt is disabled by ftrace */ + bit = ftrace_test_recursion_trylock(); + if (bit < 0) + return; + + preempt_disable_notrace(); p = get_kprobe((kprobe_opcode_t *)ip); if (!p) { p = get_kprobe((kprobe_opcode_t *)(ip - MCOUNT_INSN_SIZE)); if (unlikely(!p) || kprobe_disabled(p)) - return; + goto out; lr_saver = true; } @@ -56,6 +61,9 @@ void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip, */ __this_cpu_write(current_kprobe, NULL); } +out: + preempt_enable_notrace(); + ftrace_test_recursion_unlock(bit); } NOKPROBE_SYMBOL(kprobe_ftrace_handler); diff --git a/arch/parisc/kernel/ftrace.c b/arch/parisc/kernel/ftrace.c index 63e3ecb9da81..13d85042810a 100644 --- a/arch/parisc/kernel/ftrace.c +++ b/arch/parisc/kernel/ftrace.c @@ -207,14 +207,21 @@ void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip, struct ftrace_ops *ops, struct pt_regs *regs) { struct kprobe_ctlblk *kcb; - struct kprobe *p = get_kprobe((kprobe_opcode_t *)ip); + struct kprobe *p; + int bit; - if (unlikely(!p) || kprobe_disabled(p)) + bit = ftrace_test_recursion_trylock(); + if (bit < 0) return; + preempt_disable_notrace(); + p = get_kprobe((kprobe_opcode_t *)ip); + if (unlikely(!p) || kprobe_disabled(p)) + goto out; + if (kprobe_running()) { kprobes_inc_nmissed_count(p); - return; + goto out; } __this_cpu_write(current_kprobe, p); @@ -235,6 +242,9 @@ void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip, } } __this_cpu_write(current_kprobe, NULL); +out: + preempt_enable_notrace(); + ftrace_test_recursion_unlock(bit); } NOKPROBE_SYMBOL(kprobe_ftrace_handler); diff --git a/arch/powerpc/kernel/kprobes-ftrace.c b/arch/powerpc/kernel/kprobes-ftrace.c index 972cb28174b2..5df8d50c65ae 100644 --- a/arch/powerpc/kernel/kprobes-ftrace.c +++ b/arch/powerpc/kernel/kprobes-ftrace.c @@ -18,10 +18,16 @@ void kprobe_ftrace_handler(unsigned long nip, unsigned long parent_nip, { struct kprobe *p; struct kprobe_ctlblk *kcb; + int bit; + bit = ftrace_test_recursion_trylock(); + if (bit < 0) + return; + + preempt_disable_notrace(); p = get_kprobe((kprobe_opcode_t *)nip); if (unlikely(!p) || kprobe_disabled(p)) - return; + goto out; kcb = get_kprobe_ctlblk(); if (kprobe_running()) { @@ -52,6 +58,9 @@ void kprobe_ftrace_handler(unsigned long nip, unsigned long parent_nip, */ __this_cpu_write(current_kprobe, NULL); } +out: + preempt_enable_notrace(); + ftrace_test_recursion_unlock(bit); } NOKPROBE_SYMBOL(kprobe_ftrace_handler); diff --git a/arch/s390/kernel/ftrace.c b/arch/s390/kernel/ftrace.c index b388e87a08bf..8f31c726537a 100644 --- a/arch/s390/kernel/ftrace.c +++ b/arch/s390/kernel/ftrace.c @@ -201,14 +201,21 @@ void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip, struct ftrace_ops *ops, struct pt_regs *regs) { struct kprobe_ctlblk *kcb; - struct kprobe *p = get_kprobe((kprobe_opcode_t *)ip); + struct kprobe *p; + int bit; - if (unlikely(!p) || kprobe_disabled(p)) + bit = ftrace_test_recursion_trylock(); + if (bit < 0) return; + preempt_disable_notrace(); + p = get_kprobe((kprobe_opcode_t *)ip); + if (unlikely(!p) || kprobe_disabled(p)) + goto out; + if (kprobe_running()) { kprobes_inc_nmissed_count(p); - return; + goto out; } __this_cpu_write(current_kprobe, p); @@ -228,6 +235,9 @@ void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip, } } __this_cpu_write(current_kprobe, NULL); +out: + preempt_enable_notrace(); + ftrace_test_recursion_unlock(bit); } NOKPROBE_SYMBOL(kprobe_ftrace_handler); diff --git a/arch/x86/kernel/kprobes/ftrace.c b/arch/x86/kernel/kprobes/ftrace.c index 681a4b36e9bb..a40a6cdfcca3 100644 --- a/arch/x86/kernel/kprobes/ftrace.c +++ b/arch/x86/kernel/kprobes/ftrace.c @@ -18,11 +18,16 @@ void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip, { struct kprobe *p; struct kprobe_ctlblk *kcb; + int bit; - /* Preempt is disabled by ftrace */ + bit = ftrace_test_recursion_trylock(); + if (bit < 0) + return; + + preempt_disable_notrace(); p = get_kprobe((kprobe_opcode_t *)ip); if (unlikely(!p) || kprobe_disabled(p)) - return; + goto out; kcb = get_kprobe_ctlblk(); if (kprobe_running()) { @@ -52,6 +57,9 @@ void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip, */ __this_cpu_write(current_kprobe, NULL); } +out: + preempt_enable_notrace(); + ftrace_test_recursion_unlock(bit); } NOKPROBE_SYMBOL(kprobe_ftrace_handler); -- 2.28.0