From patchwork Tue Mar 1 02:57:25 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Long X-Patchwork-Id: 8461341 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 55CF69F372 for ; Tue, 1 Mar 2016 03:07:44 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 37C70201CD for ; Tue, 1 Mar 2016 03:07:43 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 2A6DE201BB for ; Tue, 1 Mar 2016 03:07:42 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1aaadO-00014w-Uv; Tue, 01 Mar 2016 03:06:02 +0000 Received: from mail-qk0-x234.google.com ([2607:f8b0:400d:c09::234]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1aaaYa-0003zw-8y for linux-arm-kernel@lists.infradead.org; Tue, 01 Mar 2016 03:01:07 +0000 Received: by mail-qk0-x234.google.com with SMTP id o6so64842128qkc.2 for ; Mon, 29 Feb 2016 19:00:43 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=3lC7v5OJpCQoSPwgvX2zVo8f5ay4b8K3YTRB5ot72KM=; b=HGTv18ShMrAlkaEPdyiUwYXbRkNAUfA3NRS/bW9HEb93/o7Wym1X7UvsvzbqnOoU8U qh/WcWuRl2sr6zV8lqCE2m1gjaIbBodq3hG9uSFGYpkt999KndDRXroyj7whnXaQ4CRl hFDhtfgtCiJXxDMQpaGbHcqFl/dvk5LYDdvik= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=3lC7v5OJpCQoSPwgvX2zVo8f5ay4b8K3YTRB5ot72KM=; b=mupvQQ8prodH6dcT+LtG8VhxU1A1K19U9VV8pAXdsBMlJobxEMF6ANp/KbTZH8HVAv DZgT795mbv525lo0dYFOj46LWM01TNHzxqUFPvxQJv1A5bbUt2YqnoVJzV/gxJRjhCGk d1MV67vpTEU3JIa8zwKPB8FI04A0HR8d7ePZ4UeETi3Y3VItdEz7HOHIbI1QllgycyZB CZIdBTMbLuwh3weOBAezFntwA0WQwHWR+++FvO6JP/bx8J5OMlIeQAu8HyVMGsrNPG6X Q2xC1nicGzFNxMk4vXO6wcpyPxNNO2mho4iAU3Vv+uK1J299IexX637x9eI+M9KxUgR0 VojQ== X-Gm-Message-State: AD7BkJIBbLoa3YiVZ8SBIR8dYeN33TLxWY1CBMx1UGNdbH7enIdFMNHpzj4qvF6jV2JOlTpN X-Received: by 10.55.72.67 with SMTP id v64mr23443285qka.101.1456801243042; Mon, 29 Feb 2016 19:00:43 -0800 (PST) Received: from localhost.localdomain (pool-72-71-243-249.cncdnh.fast00.myfairpoint.net. [72.71.243.249]) by smtp.googlemail.com with ESMTPSA id h5sm12195344qge.48.2016.02.29.19.00.41 (version=TLSv1/SSLv3 cipher=OTHER); Mon, 29 Feb 2016 19:00:42 -0800 (PST) From: David Long To: Catalin Marinas , Will Deacon , Sandeepa Prabhu , William Cohen , Pratyush Anand , Steve Capper , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Marc Zyngier Subject: [PATCH v10 7/9] arm64: Add trampoline code for kretprobes Date: Mon, 29 Feb 2016 21:57:25 -0500 Message-Id: <1456801047-29014-8-git-send-email-dave.long@linaro.org> X-Mailer: git-send-email 2.5.0 In-Reply-To: <1456801047-29014-1-git-send-email-dave.long@linaro.org> References: <1456801047-29014-1-git-send-email-dave.long@linaro.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20160229_190104_680114_097E9F5F X-CRM114-Status: GOOD ( 18.71 ) X-Spam-Score: -2.7 (--) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , Petr Mladek , Viresh Kumar , John Blackwood , Feng Kan , Zi Shen Lim , Dave P Martin , Yang Shi , Vladimir Murzin , Kees Cook , "Suzuki K. Poulose" , Mark Brown , =?UTF-8?q?Alex=20Benn=C3=A9e?= , Ard Biesheuvel , Greg Kroah-Hartman , Mark Salyzyn , James Morse , Christoffer Dall , Andrew Morton , Robin Murphy , Jens Wiklander , Balamurugan Shanmugam MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-4.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_MED,RP_MATCHES_RCVD,T_DKIM_INVALID,UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: William Cohen The trampoline code is used by kretprobes to capture a return from a probed function. This is done by saving the registers, calling the handler, and restoring the registers. The code then returns to the original saved caller return address. It is necessary to do this directly instead of using a software breakpoint because the code used in processing that breakpoint could itself be kprobe'd and cause a problematic reentry into the debug exception handler. Signed-off-by: William Cohen Signed-off-by: David A. Long --- arch/arm64/include/asm/kprobes.h | 2 + arch/arm64/kernel/Makefile | 1 + arch/arm64/kernel/asm-offsets.c | 22 +++++++++++ arch/arm64/kernel/kprobes.c | 5 +++ arch/arm64/kernel/kprobes_trampoline.S | 67 ++++++++++++++++++++++++++++++++++ 5 files changed, 97 insertions(+) create mode 100644 arch/arm64/kernel/kprobes_trampoline.S diff --git a/arch/arm64/include/asm/kprobes.h b/arch/arm64/include/asm/kprobes.h index 79c9511..61b4915 100644 --- a/arch/arm64/include/asm/kprobes.h +++ b/arch/arm64/include/asm/kprobes.h @@ -56,5 +56,7 @@ int kprobe_exceptions_notify(struct notifier_block *self, unsigned long val, void *data); int kprobe_breakpoint_handler(struct pt_regs *regs, unsigned int esr); int kprobe_single_step_handler(struct pt_regs *regs, unsigned int esr); +void kretprobe_trampoline(void); +void __kprobes *trampoline_probe_handler(struct pt_regs *regs); #endif /* _ARM_KPROBES_H */ diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile index 08325e5..f192b7d 100644 --- a/arch/arm64/kernel/Makefile +++ b/arch/arm64/kernel/Makefile @@ -37,6 +37,7 @@ arm64-obj-$(CONFIG_CPU_IDLE) += cpuidle.o arm64-obj-$(CONFIG_JUMP_LABEL) += jump_label.o arm64-obj-$(CONFIG_KGDB) += kgdb.o arm64-obj-$(CONFIG_KPROBES) += kprobes.o kprobes-arm64.o \ + kprobes_trampoline.o \ probes-simulate-insn.o arm64-obj-$(CONFIG_EFI) += efi.o efi-entry.stub.o arm64-obj-$(CONFIG_PCI) += pci.o diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c index fffa4ac6..460b54c 100644 --- a/arch/arm64/kernel/asm-offsets.c +++ b/arch/arm64/kernel/asm-offsets.c @@ -50,6 +50,28 @@ int main(void) DEFINE(S_X5, offsetof(struct pt_regs, regs[5])); DEFINE(S_X6, offsetof(struct pt_regs, regs[6])); DEFINE(S_X7, offsetof(struct pt_regs, regs[7])); + DEFINE(S_X8, offsetof(struct pt_regs, regs[8])); + DEFINE(S_X9, offsetof(struct pt_regs, regs[9])); + DEFINE(S_X10, offsetof(struct pt_regs, regs[10])); + DEFINE(S_X11, offsetof(struct pt_regs, regs[11])); + DEFINE(S_X12, offsetof(struct pt_regs, regs[12])); + DEFINE(S_X13, offsetof(struct pt_regs, regs[13])); + DEFINE(S_X14, offsetof(struct pt_regs, regs[14])); + DEFINE(S_X15, offsetof(struct pt_regs, regs[15])); + DEFINE(S_X16, offsetof(struct pt_regs, regs[16])); + DEFINE(S_X17, offsetof(struct pt_regs, regs[17])); + DEFINE(S_X18, offsetof(struct pt_regs, regs[18])); + DEFINE(S_X19, offsetof(struct pt_regs, regs[19])); + DEFINE(S_X20, offsetof(struct pt_regs, regs[20])); + DEFINE(S_X21, offsetof(struct pt_regs, regs[21])); + DEFINE(S_X22, offsetof(struct pt_regs, regs[22])); + DEFINE(S_X23, offsetof(struct pt_regs, regs[23])); + DEFINE(S_X24, offsetof(struct pt_regs, regs[24])); + DEFINE(S_X25, offsetof(struct pt_regs, regs[25])); + DEFINE(S_X26, offsetof(struct pt_regs, regs[26])); + DEFINE(S_X27, offsetof(struct pt_regs, regs[27])); + DEFINE(S_X28, offsetof(struct pt_regs, regs[28])); + DEFINE(S_X29, offsetof(struct pt_regs, regs[29])); DEFINE(S_LR, offsetof(struct pt_regs, regs[30])); DEFINE(S_SP, offsetof(struct pt_regs, sp)); #ifdef CONFIG_COMPAT diff --git a/arch/arm64/kernel/kprobes.c b/arch/arm64/kernel/kprobes.c index ffc5affd..98f4fe5 100644 --- a/arch/arm64/kernel/kprobes.c +++ b/arch/arm64/kernel/kprobes.c @@ -532,6 +532,11 @@ int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs) return 1; } +void __kprobes __used *trampoline_probe_handler(struct pt_regs *regs) +{ + return (void *) 0; +} + int __init arch_init_kprobes(void) { return 0; diff --git a/arch/arm64/kernel/kprobes_trampoline.S b/arch/arm64/kernel/kprobes_trampoline.S new file mode 100644 index 0000000..5a336cf --- /dev/null +++ b/arch/arm64/kernel/kprobes_trampoline.S @@ -0,0 +1,67 @@ +/* + * trampoline entry and return code for kretprobes. + */ + +#include +#include + + .text + +ENTRY(kretprobe_trampoline) + + sub sp, sp, #S_FRAME_SIZE + + stp x0, x1, [sp, #S_X0] + stp x2, x3, [sp, #S_X2] + stp x4, x5, [sp, #S_X4] + stp x6, x7, [sp, #S_X6] + stp x8, x9, [sp, #S_X8] + stp x10, x11, [sp, #S_X10] + stp x12, x13, [sp, #S_X12] + stp x14, x15, [sp, #S_X14] + stp x16, x17, [sp, #S_X16] + stp x18, x19, [sp, #S_X18] + stp x20, x21, [sp, #S_X20] + stp x22, x23, [sp, #S_X22] + stp x24, x25, [sp, #S_X24] + stp x26, x27, [sp, #S_X26] + stp x28, x29, [sp, #S_X28] + str x30, [sp, #S_LR] + add x0, sp, #S_FRAME_SIZE + str x0, [sp, #S_SP] + mrs x0, nzcv + mrs x1, daif + orr x0, x0, x1 + /* There seems no easy way to get the mode field so make one up */ + add x0, x0, #5 + str x0, [sp, #S_PSTATE] + + mov x0, sp + bl trampoline_probe_handler + /* Replace trampoline address in lr with actual + orig_ret_addr return address. */ + str x0, [sp, #S_LR] + + ldr x0, [sp, #S_PSTATE] + msr nzcv, x0 + ldp x0, x1, [sp, #S_X0] + ldp x2, x3, [sp, #S_X2] + ldp x4, x5, [sp, #S_X4] + ldp x6, x7, [sp, #S_X6] + ldp x8, x9, [sp, #S_X8] + ldp x10, x11, [sp, #S_X10] + ldp x12, x13, [sp, #S_X12] + ldp x14, x15, [sp, #S_X14] + ldp x16, x17, [sp, #S_X16] + ldp x18, x19, [sp, #S_X18] + ldp x20, x21, [sp, #S_X20] + ldp x22, x23, [sp, #S_X22] + ldp x24, x25, [sp, #S_X24] + ldp x26, x27, [sp, #S_X26] + ldp x28, x29, [sp, #S_X28] + ldr x30, [sp, #S_LR] + + add sp, sp, #S_FRAME_SIZE + ret + +ENDPROC(kretprobe_trampoline)