From patchwork Fri May 6 10:20:22 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tiezhu Yang X-Patchwork-Id: 12840974 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5219AC433F5 for ; Fri, 6 May 2022 10:20:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1390890AbiEFKY1 (ORCPT ); Fri, 6 May 2022 06:24:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34042 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1390898AbiEFKYO (ORCPT ); Fri, 6 May 2022 06:24:14 -0400 Received: from loongson.cn (mail.loongson.cn [114.242.206.163]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id A4F5751331; Fri, 6 May 2022 03:20:30 -0700 (PDT) Received: from linux.localdomain (unknown [113.200.148.30]) by mail.loongson.cn (Coremail) with SMTP id AQAAf9BxENtn9nRiaBAMAA--.48713S3; Fri, 06 May 2022 18:20:24 +0800 (CST) From: Tiezhu Yang To: Thomas Bogendoerfer , Masami Hiramatsu , Steven Rostedt , Shuah Khan Cc: Xuefeng Li , linux-mips@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 1/2] selftests/ftrace: Save kprobe_events to test log Date: Fri, 6 May 2022 18:20:22 +0800 Message-Id: <1651832423-7932-2-git-send-email-yangtiezhu@loongson.cn> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1651832423-7932-1-git-send-email-yangtiezhu@loongson.cn> References: <1651832423-7932-1-git-send-email-yangtiezhu@loongson.cn> X-CM-TRANSID: AQAAf9BxENtn9nRiaBAMAA--.48713S3 X-Coremail-Antispam: 1UD129KBjvJXoW7AF1fJF4kuFW8WFyfGF45ZFb_yoW8Gryfpa 93W3Z8Ka18J3W3JryxCw1DGFy09r4kArWUCr1rXry3Zwn5ZF9rJr1IgFWDGF93urZYgry3 Aw12yry7XFykJa7anT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUBS14x267AKxVW5JVWrJwAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2048vs2IY020E87I2jVAFwI0_Jr4l82xGYIkIc2 x26xkF7I0E14v26r1I6r4UM28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48ve4kI8wA2z4x0 Y4vE2Ix0cI8IcVAFwI0_Xr0_Ar1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI0_Gr1j6F4UJw A2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xvwVC2z280aVCY1x0267AKxVW0oVCq3wAS 0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0I7IYx2 IY67AKxVWUGVWUXwAv7VC2z280aVAFwI0_Gr0_Cr1lOx8S6xCaFVCjc4AY6r1j6r4UM4x0 Y48IcxkI7VAKI48JM4x0x7Aq67IIx4CEVc8vx2IErcIFxwCY02Avz4vE14v_Gw1l42xK82 IYc2Ij64vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1lx2IqxVAqx4xG67AKxVWUJVWUGwC2 0s026x8GjcxK67AKxVWUGVWUWwC2zVAF1VAY17CE14v26r1q6r43MIIYrxkI7VAKI48JMI IF0xvE2Ix0cI8IcVAFwI0_Jr0_JF4lIxAIcVC0I7IYx2IY6xkF7I0E14v26r4j6F4UMIIF 0xvE42xK8VAvwI8IcIk0rVWUJVWUCwCI42IY6I8E87Iv67AKxVWUJVW8JwCI42IY6I8E87 Iv6xkF7I0E14v26r4j6r4UJbIYCTnIWIevJa73UjIFyTuYvjfU5UUUUUUUU X-CM-SenderInfo: p1dqw3xlh2x3gn0dqz5rrqw2lrqou0/ Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org It may lead to kernel panic when execute the following testcase on mips: # cd tools/testing/selftests/ftrace # ./ftracetest test.d/kprobe/multiple_kprobes.tc A preliminary analysis shows that the issue is related with echo 1 > events/kprobes/enable after add the 256 probe points. In order to find the root cause, I want to verify which probe point has problem, so it is necessary to save kprobe_events to test log. With this patch, we can get the 256 probe points in the test log through the following command: # ./ftracetest test.d/kprobe/multiple_kprobes.tc -vvv -k Signed-off-by: Tiezhu Yang Acked-by: Masami Hiramatsu --- tools/testing/selftests/ftrace/test.d/kprobe/multiple_kprobes.tc | 2 ++ 1 file changed, 2 insertions(+) diff --git a/tools/testing/selftests/ftrace/test.d/kprobe/multiple_kprobes.tc b/tools/testing/selftests/ftrace/test.d/kprobe/multiple_kprobes.tc index 312d237..be754f5 100644 --- a/tools/testing/selftests/ftrace/test.d/kprobe/multiple_kprobes.tc +++ b/tools/testing/selftests/ftrace/test.d/kprobe/multiple_kprobes.tc @@ -25,6 +25,8 @@ if [ $L -ne 256 ]; then exit_fail fi +cat kprobe_events >> $testlog + echo 1 > events/kprobes/enable echo 0 > events/kprobes/enable echo > kprobe_events From patchwork Fri May 6 10:20:23 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tiezhu Yang X-Patchwork-Id: 12840976 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9A08BC43217 for ; Fri, 6 May 2022 10:20:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1390896AbiEFKY2 (ORCPT ); Fri, 6 May 2022 06:24:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34090 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1390901AbiEFKYP (ORCPT ); Fri, 6 May 2022 06:24:15 -0400 Received: from loongson.cn (mail.loongson.cn [114.242.206.163]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id A50325158B; Fri, 6 May 2022 03:20:29 -0700 (PDT) Received: from linux.localdomain (unknown [113.200.148.30]) by mail.loongson.cn (Coremail) with SMTP id AQAAf9BxENtn9nRiaBAMAA--.48713S4; Fri, 06 May 2022 18:20:25 +0800 (CST) From: Tiezhu Yang To: Thomas Bogendoerfer , Masami Hiramatsu , Steven Rostedt , Shuah Khan Cc: Xuefeng Li , linux-mips@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 2/2] MIPS: Use NOKPROBE_SYMBOL() instead of __kprobes annotation Date: Fri, 6 May 2022 18:20:23 +0800 Message-Id: <1651832423-7932-3-git-send-email-yangtiezhu@loongson.cn> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1651832423-7932-1-git-send-email-yangtiezhu@loongson.cn> References: <1651832423-7932-1-git-send-email-yangtiezhu@loongson.cn> X-CM-TRANSID: AQAAf9BxENtn9nRiaBAMAA--.48713S4 X-Coremail-Antispam: 1UD129KBjvJXoWxKw1DtrWDZw1kZr1UAr4fXwb_yoW3JF1xpF 98Aw1rKr4rXa4v9F9rAwsYvr1Syr4rZ3yUCrW7G34Sq3W5tr15tF1IgrWjyFy5GrZYvF13 ZF4YyryUZFWxC37anT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUBS14x267AKxVWrJVCq3wAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2048vs2IY020E87I2jVAFwI0_Jryl82xGYIkIc2 x26xkF7I0E14v26r4j6ryUM28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48ve4kI8wA2z4x0 Y4vE2Ix0cI8IcVAFwI0_Xr0_Ar1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI0_Gr1j6F4UJw A2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xvwVC2z280aVCY1x0267AKxVW0oVCq3wAS 0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0I7IYx2 IY67AKxVWUGVWUXwAv7VC2z280aVAFwI0_Gr0_Cr1lOx8S6xCaFVCjc4AY6r1j6r4UM4x0 Y48IcxkI7VAKI48JM4x0x7Aq67IIx4CEVc8vx2IErcIFxwCY02Avz4vE14v_Gw1l42xK82 IYc2Ij64vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1lx2IqxVAqx4xG67AKxVWUJVWUGwC2 0s026x8GjcxK67AKxVWUGVWUWwC2zVAF1VAY17CE14v26r1q6r43MIIYrxkI7VAKI48JMI IF0xvE2Ix0cI8IcVAFwI0_Jr0_JF4lIxAIcVC0I7IYx2IY6xkF7I0E14v26r4j6F4UMIIF 0xvE42xK8VAvwI8IcIk0rVWUJVWUCwCI42IY6I8E87Iv67AKxVWUJVW8JwCI42IY6I8E87 Iv6xkF7I0E14v26r4j6r4UJbIYCTnIWIevJa73UjIFyTuYvjfU8OJ5UUUUU X-CM-SenderInfo: p1dqw3xlh2x3gn0dqz5rrqw2lrqou0/ Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org If define CONFIG_KPROBES, __kprobes annotation forces the whole function into the ".kprobes.text" section, NOKPROBE_SYMBOL() only stores the given function address in the "_kprobe_blacklist" section which is introduced to maintain kprobes blacklist. Modify the related code to use NOKPROBE_SYMBOL() to protect functions from kprobes instead of __kprobes annotation under arch/mips. No obvious functional change in this patch, some more work needs to be done to fix the kernel panic when execute the following testcase on mips: # cd tools/testing/selftests/ftrace # ./ftracetest test.d/kprobe/multiple_kprobes.tc Signed-off-by: Tiezhu Yang --- arch/mips/kernel/kprobes.c | 39 ++++++++++++++++++++++++++------------- arch/mips/mm/fault.c | 6 ++++-- 2 files changed, 30 insertions(+), 15 deletions(-) diff --git a/arch/mips/kernel/kprobes.c b/arch/mips/kernel/kprobes.c index 6c7f3b1..321153c 100644 --- a/arch/mips/kernel/kprobes.c +++ b/arch/mips/kernel/kprobes.c @@ -44,10 +44,11 @@ static const union mips_instruction breakpoint2_insn = { DEFINE_PER_CPU(struct kprobe *, current_kprobe); DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk); -static int __kprobes insn_has_delayslot(union mips_instruction insn) +static int insn_has_delayslot(union mips_instruction insn) { return __insn_has_delay_slot(insn); } +NOKPROBE_SYMBOL(insn_has_delayslot); /* * insn_has_ll_or_sc function checks whether instruction is ll or sc @@ -56,7 +57,7 @@ static int __kprobes insn_has_delayslot(union mips_instruction insn) * instructions; cannot do much about breakpoint in the middle of * ll/sc pair; it is upto user to avoid those places */ -static int __kprobes insn_has_ll_or_sc(union mips_instruction insn) +static int insn_has_ll_or_sc(union mips_instruction insn) { int ret = 0; @@ -72,8 +73,9 @@ static int __kprobes insn_has_ll_or_sc(union mips_instruction insn) } return ret; } +NOKPROBE_SYMBOL(insn_has_ll_or_sc); -int __kprobes arch_prepare_kprobe(struct kprobe *p) +int arch_prepare_kprobe(struct kprobe *p) { union mips_instruction insn; union mips_instruction prev_insn; @@ -132,26 +134,30 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p) out: return ret; } +NOKPROBE_SYMBOL(arch_prepare_kprobe); -void __kprobes arch_arm_kprobe(struct kprobe *p) +void arch_arm_kprobe(struct kprobe *p) { *p->addr = breakpoint_insn; flush_insn_slot(p); } +NOKPROBE_SYMBOL(arch_arm_kprobe); -void __kprobes arch_disarm_kprobe(struct kprobe *p) +void arch_disarm_kprobe(struct kprobe *p) { *p->addr = p->opcode; flush_insn_slot(p); } +NOKPROBE_SYMBOL(arch_disarm_kprobe); -void __kprobes arch_remove_kprobe(struct kprobe *p) +void arch_remove_kprobe(struct kprobe *p) { if (p->ainsn.insn) { free_insn_slot(p->ainsn.insn, 0); p->ainsn.insn = NULL; } } +NOKPROBE_SYMBOL(arch_remove_kprobe); static void save_previous_kprobe(struct kprobe_ctlblk *kcb) { @@ -257,7 +263,7 @@ static void prepare_singlestep(struct kprobe *p, struct pt_regs *regs, * breakpoint trap. In case of branch instructions, the target * epc to be restored. */ -static void __kprobes resume_execution(struct kprobe *p, +static void resume_execution(struct kprobe *p, struct pt_regs *regs, struct kprobe_ctlblk *kcb) { @@ -268,8 +274,9 @@ static void __kprobes resume_execution(struct kprobe *p, regs->cp0_epc = orig_epc + 4; } } +NOKPROBE_SYMBOL(resume_execution); -static int __kprobes kprobe_handler(struct pt_regs *regs) +static int kprobe_handler(struct pt_regs *regs) { struct kprobe *p; int ret = 0; @@ -367,8 +374,9 @@ static int __kprobes kprobe_handler(struct pt_regs *regs) return ret; } +NOKPROBE_SYMBOL(kprobe_handler); -static inline int post_kprobe_handler(struct pt_regs *regs) +static int post_kprobe_handler(struct pt_regs *regs) { struct kprobe *cur = kprobe_running(); struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); @@ -396,6 +404,7 @@ static inline int post_kprobe_handler(struct pt_regs *regs) return 1; } +NOKPROBE_SYMBOL(post_kprobe_handler); int kprobe_fault_handler(struct pt_regs *regs, int trapnr) { @@ -415,7 +424,7 @@ int kprobe_fault_handler(struct pt_regs *regs, int trapnr) /* * Wrapper routine for handling exceptions. */ -int __kprobes kprobe_exceptions_notify(struct notifier_block *self, +int kprobe_exceptions_notify(struct notifier_block *self, unsigned long val, void *data) { @@ -446,6 +455,7 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self, } return ret; } +NOKPROBE_SYMBOL(kprobe_exceptions_notify); /* * Function return probe trampoline: @@ -469,7 +479,7 @@ static void __used kretprobe_trampoline_holder(void) void __kretprobe_trampoline(void); -void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri, +void arch_prepare_kretprobe(struct kretprobe_instance *ri, struct pt_regs *regs) { ri->ret_addr = (kprobe_opcode_t *) regs->regs[31]; @@ -478,11 +488,12 @@ void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri, /* Replace the return addr with trampoline addr */ regs->regs[31] = (unsigned long)__kretprobe_trampoline; } +NOKPROBE_SYMBOL(arch_prepare_kretprobe); /* * Called when the probe at kretprobe trampoline is hit */ -static int __kprobes trampoline_probe_handler(struct kprobe *p, +static int trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs) { instruction_pointer(regs) = __kretprobe_trampoline_handler(regs, NULL); @@ -493,14 +504,16 @@ static int __kprobes trampoline_probe_handler(struct kprobe *p, */ return 1; } +NOKPROBE_SYMBOL(trampoline_probe_handler); -int __kprobes arch_trampoline_kprobe(struct kprobe *p) +int arch_trampoline_kprobe(struct kprobe *p) { if (p->addr == (kprobe_opcode_t *)__kretprobe_trampoline) return 1; return 0; } +NOKPROBE_SYMBOL(arch_trampoline_kprobe); static struct kprobe trampoline_p = { .addr = (kprobe_opcode_t *)__kretprobe_trampoline, diff --git a/arch/mips/mm/fault.c b/arch/mips/mm/fault.c index 44f9810..b08bc55 100644 --- a/arch/mips/mm/fault.c +++ b/arch/mips/mm/fault.c @@ -35,7 +35,7 @@ int show_unhandled_signals = 1; * and the problem, and then passes it off to one of the appropriate * routines. */ -static void __kprobes __do_page_fault(struct pt_regs *regs, unsigned long write, +static void __do_page_fault(struct pt_regs *regs, unsigned long write, unsigned long address) { struct vm_area_struct * vma = NULL; @@ -322,8 +322,9 @@ static void __kprobes __do_page_fault(struct pt_regs *regs, unsigned long write, } #endif } +NOKPROBE_SYMBOL(__do_page_fault); -asmlinkage void __kprobes do_page_fault(struct pt_regs *regs, +asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long write, unsigned long address) { enum ctx_state prev_state; @@ -332,3 +333,4 @@ asmlinkage void __kprobes do_page_fault(struct pt_regs *regs, __do_page_fault(regs, write, address); exception_exit(prev_state); } +NOKPROBE_SYMBOL(do_page_fault);