From patchwork Fri Jan 28 14:32:53 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 12728620 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 68BF3C433EF for ; Fri, 28 Jan 2022 14:33:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1349285AbiA1OdI (ORCPT ); Fri, 28 Jan 2022 09:33:08 -0500 Received: from ams.source.kernel.org ([145.40.68.75]:50106 "EHLO ams.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1349242AbiA1OdB (ORCPT ); Fri, 28 Jan 2022 09:33:01 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 6105EB825E8; Fri, 28 Jan 2022 14:33:00 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 90865C340E0; Fri, 28 Jan 2022 14:32:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1643380379; bh=/l2AYnhwkGK1vuSSo7mgSDc0f2wUI76MI5naeFuvPJo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XU0UL1TQ4cf+7VG6oppMhMOnRT7QodhTVa2Qm9zSBYaUMvPlwa2EV45HAsGn44YG2 g0aGOX/+kH6shchAVwnzgM2oSXKd7CDYwIhCgs1t8TBBl13fE68YYySnduuJYTpXOZ cJShV521Oa8iNY4ZLu6UM4ZewJ3uKn9t8wapfRzM60Tg615/iJx0foaXzqFE3K0BLt KvuXza1xswJxkdvqLhy9Bd36cwUewZtSt14CxPlKW6inpyn8eebi9YSO59YKesXRSr LD/3UkJpAYVpV9kS0LmLip9dtwtCQSYK86edchGQuSPYERCkp6E77AzrMk3dclIUj+ cJn3ZvbF7r7Jg== From: Masami Hiramatsu To: Jiri Olsa , Alexei Starovoitov Cc: Daniel Borkmann , Andrii Nakryiko , Masami Hiramatsu , netdev@vger.kernel.org, bpf@vger.kernel.org, lkml , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , Steven Rostedt , "Naveen N . Rao" , Anil S Keshavamurthy , "David S . Miller" Subject: [PATCH v6 05/10] ARM: rethook: Add rethook arm implementation Date: Fri, 28 Jan 2022 23:32:53 +0900 Message-Id: <164338037327.2429999.13110792485526743529.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <164338031590.2429999.6203979005944292576.stgit@devnote2> References: <164338031590.2429999.6203979005944292576.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Add rethook arm implementation. Most of the code has been copied from kretprobes on arm. Signed-off-by: Masami Hiramatsu --- Changes in v5: - Fix build error when !CONFIG_KRETPROBES --- arch/arm/Kconfig | 1 + arch/arm/include/asm/stacktrace.h | 4 +- arch/arm/kernel/stacktrace.c | 6 +++ arch/arm/probes/Makefile | 1 + arch/arm/probes/rethook.c | 71 +++++++++++++++++++++++++++++++++++++ 5 files changed, 81 insertions(+), 2 deletions(-) create mode 100644 arch/arm/probes/rethook.c diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index c2724d986fa0..2fe24bbca618 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -106,6 +106,7 @@ config ARM select HAVE_MOD_ARCH_SPECIFIC select HAVE_NMI select HAVE_OPTPROBES if !THUMB2_KERNEL + select HAVE_RETHOOK select HAVE_PERF_EVENTS select HAVE_PERF_REGS select HAVE_PERF_USER_STACK_DUMP diff --git a/arch/arm/include/asm/stacktrace.h b/arch/arm/include/asm/stacktrace.h index 8f54f9ad8a9b..babed1707ca8 100644 --- a/arch/arm/include/asm/stacktrace.h +++ b/arch/arm/include/asm/stacktrace.h @@ -14,7 +14,7 @@ struct stackframe { unsigned long sp; unsigned long lr; unsigned long pc; -#ifdef CONFIG_KRETPROBES +#if defined(CONFIG_KRETPROBES) || defined(CONFIG_RETHOOK) struct llist_node *kr_cur; struct task_struct *tsk; #endif @@ -27,7 +27,7 @@ void arm_get_current_stackframe(struct pt_regs *regs, struct stackframe *frame) frame->sp = regs->ARM_sp; frame->lr = regs->ARM_lr; frame->pc = regs->ARM_pc; -#ifdef CONFIG_KRETPROBES +#if defined(CONFIG_KRETPROBES) || defined(CONFIG_RETHOOK) frame->kr_cur = NULL; frame->tsk = current; #endif diff --git a/arch/arm/kernel/stacktrace.c b/arch/arm/kernel/stacktrace.c index 75e905508f27..f509c6be4f57 100644 --- a/arch/arm/kernel/stacktrace.c +++ b/arch/arm/kernel/stacktrace.c @@ -1,6 +1,7 @@ // SPDX-License-Identifier: GPL-2.0-only #include #include +#include #include #include #include @@ -66,6 +67,11 @@ int notrace unwind_frame(struct stackframe *frame) frame->sp = *(unsigned long *)(fp - 8); frame->pc = *(unsigned long *)(fp - 4); #endif +#ifdef CONFIG_RETHOOK + if (is_rethook_trampoline(frame->pc)) + frame->pc = rethook_find_ret_addr(frame->tsk, frame->fp, + &frame->kr_cur); +#endif #ifdef CONFIG_KRETPROBES if (is_kretprobe_trampoline(frame->pc)) frame->pc = kretprobe_find_ret_addr(frame->tsk, diff --git a/arch/arm/probes/Makefile b/arch/arm/probes/Makefile index 8b0ea5ace100..10c083a22223 100644 --- a/arch/arm/probes/Makefile +++ b/arch/arm/probes/Makefile @@ -6,3 +6,4 @@ obj-$(CONFIG_KPROBES) += decode-thumb.o else obj-$(CONFIG_KPROBES) += decode-arm.o endif +obj-$(CONFIG_RETHOOK) += rethook.o diff --git a/arch/arm/probes/rethook.c b/arch/arm/probes/rethook.c new file mode 100644 index 000000000000..adc16cdf358a --- /dev/null +++ b/arch/arm/probes/rethook.c @@ -0,0 +1,71 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * arm implementation of rethook. Mostly copied from arch/arm/probes/kprobes/core.c + */ + +#include +#include + +/* Called from arch_rethook_trampoline */ +static __used unsigned long arch_rethook_trampoline_callback(struct pt_regs *regs) +{ + return rethook_trampoline_handler(regs, regs->ARM_fp); +} +NOKPROBE_SYMBOL(arch_rethook_trampoline_callback); + +/* + * When a rethook'ed function returns, it returns to arch_rethook_trampoline + * which calls rethook callback. We construct a struct pt_regs to + * give a view of registers r0-r11, sp, lr, and pc to the user + * return-handler. This is not a complete pt_regs structure, but that + * should be enough for stacktrace from the return handler with or + * without pt_regs. + */ +void __naked arch_rethook_trampoline(void) +{ + __asm__ __volatile__ ( +#ifdef CONFIG_FRAME_POINTER + "ldr lr, =arch_rethook_trampoline \n\t" + /* this makes a framepointer on pt_regs. */ +#ifdef CONFIG_CC_IS_CLANG + "stmdb sp, {sp, lr, pc} \n\t" + "sub sp, sp, #12 \n\t" + /* In clang case, pt_regs->ip = lr. */ + "stmdb sp!, {r0 - r11, lr} \n\t" + /* fp points regs->r11 (fp) */ + "add fp, sp, #44 \n\t" +#else /* !CONFIG_CC_IS_CLANG */ + /* In gcc case, pt_regs->ip = fp. */ + "stmdb sp, {fp, sp, lr, pc} \n\t" + "sub sp, sp, #16 \n\t" + "stmdb sp!, {r0 - r11} \n\t" + /* fp points regs->r15 (pc) */ + "add fp, sp, #60 \n\t" +#endif /* CONFIG_CC_IS_CLANG */ +#else /* !CONFIG_FRAME_POINTER */ + "sub sp, sp, #16 \n\t" + "stmdb sp!, {r0 - r11} \n\t" +#endif /* CONFIG_FRAME_POINTER */ + "mov r0, sp \n\t" + "bl arch_rethook_trampoline_callback \n\t" + "mov lr, r0 \n\t" + "ldmia sp!, {r0 - r11} \n\t" + "add sp, sp, #16 \n\t" +#ifdef CONFIG_THUMB2_KERNEL + "bx lr \n\t" +#else + "mov pc, lr \n\t" +#endif + : : : "memory"); +} +NOKPROBE_SYMBOL(arch_rethook_trampoline); + +void arch_rethook_prepare(struct rethook_node *rh, struct pt_regs *regs) +{ + rh->ret_addr = regs->ARM_lr; + rh->frame = regs->ARM_fp; + + /* Replace the return addr with trampoline addr. */ + regs->ARM_lr = (unsigned long)arch_rethook_trampoline; +} +NOKPROBE_SYMBOL(arch_rethook_prepare);