From patchwork Tue Nov 5 08:45:45 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vijay Kilari X-Patchwork-Id: 3139961 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 54020BEEB2 for ; Tue, 5 Nov 2013 08:49:19 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 06CC0205EC for ; Tue, 5 Nov 2013 08:49:18 +0000 (UTC) Received: from casper.infradead.org (casper.infradead.org [85.118.1.10]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 344F7205EA for ; Tue, 5 Nov 2013 08:49:13 +0000 (UTC) Received: from merlin.infradead.org ([2001:4978:20e::2]) by casper.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1VdcIz-0006YT-AG; Tue, 05 Nov 2013 08:48:10 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1VdcIh-0002yR-NN; Tue, 05 Nov 2013 08:47:51 +0000 Received: from mail-pd0-x236.google.com ([2607:f8b0:400e:c02::236]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1VdcIf-0002w5-1k for linux-arm-kernel@lists.infradead.org; Tue, 05 Nov 2013 08:47:49 +0000 Received: by mail-pd0-f182.google.com with SMTP id q10so8016073pdj.13 for ; Tue, 05 Nov 2013 00:47:27 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=zdOTUkHpoA96jRem02zMtM+BJ7QvSpaLam3i7uz+vGo=; b=scwbZBvrC3aFQMbRJwOLjOEciMedKmIJfOsXGQ+80ttlgNCMCPzL8PkQg4AtNSYO0j elQSPi8ok3DWP9iDbulxLStc+ciIoJD+d+krt0+vdL2SKuNgt0D+B5mHWKHp4dLwgsfg O4OQUoXYExX7hIPtXqjYWI0f+bIxnpR3VvhYmTYxQWelByBbp4oKqOu21tiZD8OIO4+2 wpwoK3JXnklL0xb7xA7EU+4zS4+QnjUju9/oQHmHKMY+LAXEVeVDtMUwu6hChrgyxcj1 A5/mYk/ycE9DHrqyiuBp5aWPSPGdxRX3nNRaeKlF9YD1KQWBQPwL37prJIKzQfop8XWC 7S2A== X-Received: by 10.68.180.131 with SMTP id do3mr22000479pbc.34.1383641247073; Tue, 05 Nov 2013 00:47:27 -0800 (PST) Received: from ubuntu.caveonetworks.com ([115.119.134.194]) by mx.google.com with ESMTPSA id i6sm33163124pbc.1.2013.11.05.00.47.20 for (version=TLSv1.1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Tue, 05 Nov 2013 00:47:26 -0800 (PST) From: vijay.kilari@gmail.com To: will.deacon@arm.com, sandeepa.prabhu@linaro.org, jason.wessel@windriver.com, takahiro.akashi@linaro.org, Catalin.Marinas@arm.com Subject: [PATCH v4 3/4] AArch64: KGDB: Add step debugging support Date: Tue, 5 Nov 2013 14:15:45 +0530 Message-Id: <1383641146-27274-4-git-send-email-vijay.kilari@gmail.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1383641146-27274-1-git-send-email-vijay.kilari@gmail.com> References: <1383641146-27274-1-git-send-email-vijay.kilari@gmail.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20131105_034749_204715_F2BDE3ED X-CRM114-Status: GOOD ( 17.17 ) X-Spam-Score: -2.0 (--) Cc: Prasun.Kapoor@caviumnetworks.com, Vijaya Kumar K , linaro-kernel@lists.linaro.org, linux@arm.linux.org.uk, linux-arm-kernel@lists.infradead.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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_ADSP_CUSTOM_MED, DKIM_SIGNED, FREEMAIL_FROM, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, T_DKIM_INVALID, UNPARSEABLE_RELAY autolearn=ham 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: Vijaya Kumar K Add KGDB software step debugging support for EL1 debug in AArch64 mode. KGDB registers step debug handler with debug monitor. On receiving 'step' command from GDB tool, target enables software step debugging and step address is updated. If no step address is received from GDB tool, target assumes next step address is current PC. Software Step debugging is disabled when 'continue' command is received Signed-off-by: Vijaya Kumar K --- arch/arm64/kernel/kgdb.c | 67 +++++++++++++++++++++++++++++++++++++++------- 1 file changed, 58 insertions(+), 9 deletions(-) diff --git a/arch/arm64/kernel/kgdb.c b/arch/arm64/kernel/kgdb.c index ec624bc..f10f2ba 100644 --- a/arch/arm64/kernel/kgdb.c +++ b/arch/arm64/kernel/kgdb.c @@ -137,13 +137,26 @@ void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc) static int compiled_break; +static void kgdb_arch_update_addr(struct pt_regs *regs, + char *remcom_in_buffer) +{ + unsigned long addr; + char *ptr; + + ptr = &remcom_in_buffer[1]; + if (kgdb_hex2long(&ptr, &addr)) + kgdb_arch_set_pc(regs, addr); + else if (compiled_break == 1) + kgdb_arch_set_pc(regs, regs->pc + 4); + + compiled_break = 0; +} + int kgdb_arch_handle_exception(int exception_vector, int signo, int err_code, char *remcom_in_buffer, char *remcom_out_buffer, struct pt_regs *linux_regs) { - unsigned long addr; - char *ptr; int err; switch (remcom_in_buffer[0]) { @@ -153,6 +166,8 @@ int kgdb_arch_handle_exception(int exception_vector, int signo, * Packet D (Detach), k (kill). No special handling * is required here */ + atomic_set(&kgdb_cpu_doing_single_step, -1); + kgdb_single_step = 0; err = 0; break; case 'c': @@ -164,16 +179,39 @@ int kgdb_arch_handle_exception(int exception_vector, int signo, * to the next instruction else we will just breakpoint * over and over again. */ - ptr = &remcom_in_buffer[1]; - if (kgdb_hex2long(&ptr, &addr)) - kgdb_arch_set_pc(linux_regs, addr); - else if (compiled_break == 1) - kgdb_arch_set_pc(linux_regs, linux_regs->pc + 4); + kgdb_arch_update_addr(linux_regs, remcom_in_buffer); + atomic_set(&kgdb_cpu_doing_single_step, -1); + kgdb_single_step = 0; - compiled_break = 0; + /* + * Received continue command, disable single step + */ + if (kernel_active_single_step()) + kernel_disable_single_step(); err = 0; break; + case 's': + /* + * Update step address value with address passed + * with step packet. + * On debug exception return PC is copied to ELR + * So just update PC. + * If no step address is passed, resume from the address + * pointed by PC. Do not update PC + */ + kgdb_arch_update_addr(linux_regs, remcom_in_buffer); + atomic_set(&kgdb_cpu_doing_single_step, raw_smp_processor_id()); + kgdb_single_step = 1; + + /* + * Enable single step handling + */ + if (!kernel_active_single_step()) + kernel_enable_single_step(linux_regs); + err = 0; + break; + default: err = -1; } @@ -194,6 +232,12 @@ static int kgdb_compiled_brk_fn(struct pt_regs *regs, unsigned int esr) return 0; } +static int kgdb_step_brk_fn(struct pt_regs *regs, unsigned int esr) +{ + kgdb_handle_exception(1, SIGTRAP, 0, regs); + return 0; +} + static struct break_hook kgdb_brkpt_hook = { .esr_mask = 0xffffffff, .esr_val = DBG_ESR_VAL_BRK(KGDB_DYN_DGB_BRK_IMM), @@ -206,6 +250,10 @@ static struct break_hook kgdb_compiled_brkpt_hook = { .fn = kgdb_compiled_brk_fn }; +static struct step_hook kgdb_step_hook = { + .fn = kgdb_step_brk_fn +}; + static void kgdb_call_nmi_hook(void *ignored) { kgdb_nmicallback(raw_smp_processor_id(), get_irq_regs()); @@ -259,7 +307,7 @@ int kgdb_arch_init(void) register_break_hook(&kgdb_brkpt_hook); register_break_hook(&kgdb_compiled_brkpt_hook); - + register_step_hook(&kgdb_step_hook); return 0; } @@ -272,6 +320,7 @@ void kgdb_arch_exit(void) { unregister_break_hook(&kgdb_brkpt_hook); unregister_break_hook(&kgdb_compiled_brkpt_hook); + unregister_step_hook(&kgdb_step_hook); unregister_die_notifier(&kgdb_notifier); }