From patchwork Fri Oct 18 11:07:47 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vijay Kilari X-Patchwork-Id: 3065711 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 [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 1E1909F243 for ; Fri, 18 Oct 2013 11:10:57 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 8E9832044B for ; Fri, 18 Oct 2013 11:10:55 +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 9B14D20461 for ; Fri, 18 Oct 2013 11:10:53 +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 1VX7w5-0004oW-Ed; Fri, 18 Oct 2013 11:09:43 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1VX7vh-0007fD-Eq; Fri, 18 Oct 2013 11:09:17 +0000 Received: from mail-pd0-x230.google.com ([2607:f8b0:400e:c02::230]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1VX7vS-0007cN-Tw for linux-arm-kernel@lists.infradead.org; Fri, 18 Oct 2013 11:09:08 +0000 Received: by mail-pd0-f176.google.com with SMTP id g10so3512809pdj.7 for ; Fri, 18 Oct 2013 04:08:43 -0700 (PDT) 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=esX40R1gJOMgrdvIyguKywC2eFq5ksE+PRg8m1Zh93U=; b=FrOxclkqP23lBjYnrD3ylp6P2F7Gpn3nCpO9l3B2b1BOt0QvouKHHPue6LnVk8wZ6W px7NDnxe4bxxOa0JzjYXonDzpzxbnHEL73OEGz+1yA2fdOxpBqylg4l52r7MBdzKkHQH XCl8dPZJgh8LAq3xfgKb5MFecFBvYf05CR34IMDAFs+ld1AHCo79YXRh+n+/X6oM35B1 2HcT6oJOJzEHMZ8Jbi7xIxvbhUsoyfKKrG7+hcSgAMU0bUmjEnh5vFiyauJdGnA53jNs wojtYQRxPf/sEkU6cuOi1jSX62bAdu5vHECdGMW/jauqOClmXWFe5Whrx5wXJARnOltB qMiQ== X-Received: by 10.68.189.229 with SMTP id gl5mr916749pbc.195.1382094523521; Fri, 18 Oct 2013 04:08:43 -0700 (PDT) Received: from ubuntu.caveonetworks.com ([115.119.134.194]) by mx.google.com with ESMTPSA id xs1sm3587419pac.7.2013.10.18.04.08.40 for (version=TLSv1.1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Fri, 18 Oct 2013 04:08:43 -0700 (PDT) From: vijay.kilari@gmail.com To: will.deacon@arm.com, sandeepa.prabhu@linaro.org, jason.wessel@windriver.com Subject: [PATCH v3 2/4] AArch64: KGDB: Add Basic KGDB support Date: Fri, 18 Oct 2013 16:37:47 +0530 Message-Id: <1382094469-7971-3-git-send-email-vijay.kilari@gmail.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1382094469-7971-1-git-send-email-vijay.kilari@gmail.com> References: <1382094469-7971-1-git-send-email-vijay.kilari@gmail.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20131018_070903_252403_BE67F78E X-CRM114-Status: GOOD ( 26.17 ) X-Spam-Score: -2.0 (--) Cc: linaro-kernel@lists.linaro.org, linux@arm.linux.org.uk, Prasun.Kapoor@caviumnetworks.com, Vijaya Kumar K , takahiro.akashi@linaro.org, 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=-4.5 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=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: Vijaya Kumar K Add KGDB debug support for kernel debugging. With this patch, basic KGDB debugging is possible.GDB register layout is updated and GDB tool can establish connection with target and can set/clear breakpoints. Signed-off-by: Vijaya Kumar K --- arch/arm64/include/asm/debug-monitors.h | 46 +++++ arch/arm64/include/asm/kgdb.h | 86 ++++++++++ arch/arm64/kernel/Makefile | 1 + arch/arm64/kernel/kgdb.c | 283 +++++++++++++++++++++++++++++++ 4 files changed, 416 insertions(+) diff --git a/arch/arm64/include/asm/debug-monitors.h b/arch/arm64/include/asm/debug-monitors.h index 6231479..d00c440 100644 --- a/arch/arm64/include/asm/debug-monitors.h +++ b/arch/arm64/include/asm/debug-monitors.h @@ -26,6 +26,52 @@ #define DBG_ESR_EVT_HWWP 0x2 #define DBG_ESR_EVT_BRK 0x6 +/* + * Break point instruction encoding + */ +#define BREAK_INSTR_SIZE 4 + +/* + * ESR values expected for dynamic and compile time BRK instruction + */ +#define DBG_ESR_VAL_BRK(x) (0xf2000000 | ((x) & 0xfffff)) + +/* + * #imm16 values used for BRK instruction generation + * 0: for dynamic BRK instruction + * 1: for compile time BRK instruction + */ +#define KGDB_DYN_DGB_BRK_IMM 0 +#define KDBG_COMPILED_DBG_BRK_IMM 1 + +/* + * BRK instruction encoding + * The #imm16 value should be placed at bits[20:5] within BRK ins + */ +#define AARCH64_BREAK_MON 0xd4200000 + +/* + * Extract byte from BRK instruction + */ +#define KGDB_DYN_DGB_BRK_INS_BYTE(x) \ + ((((AARCH64_BREAK_MON) & 0xffe0001f) >> (x * 8)) & 0xff) + +/* + * Extract byte from BRK #imm16 + */ +#define KGBD_DYN_DGB_BRK_IMM_BYTE(x) \ + (((((KGDB_DYN_DGB_BRK_IMM) & 0xffff) << 5) >> (x * 8)) & 0xff) + +#define KGDB_DYN_DGB_BRK_BYTE(x) \ + (KGDB_DYN_DGB_BRK_INS_BYTE(x) | KGBD_DYN_DGB_BRK_IMM_BYTE(x)) + +#define KGDB_DYN_BRK_INS_BYTE0 KGDB_DYN_DGB_BRK_BYTE(0) +#define KGDB_DYN_BRK_INS_BYTE1 KGDB_DYN_DGB_BRK_BYTE(1) +#define KGDB_DYN_BRK_INS_BYTE2 KGDB_DYN_DGB_BRK_BYTE(2) +#define KGDB_DYN_BRK_INS_BYTE3 KGDB_DYN_DGB_BRK_BYTE(3) + +#define CACHE_FLUSH_IS_SAFE 1 + enum debug_el { DBG_ACTIVE_EL0 = 0, DBG_ACTIVE_EL1, diff --git a/arch/arm64/include/asm/kgdb.h b/arch/arm64/include/asm/kgdb.h new file mode 100644 index 0000000..5c9faa9 --- /dev/null +++ b/arch/arm64/include/asm/kgdb.h @@ -0,0 +1,86 @@ +/* + * AArch64 KGDB support + * + * Based on arch/arm/include/kgdb.h + * + * Copyright (C) 2013 Cavium Inc. + * Author: Vijaya Kumar K + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see . + */ + +#ifndef __ARM_KGDB_H__ +#define __ARM_KGDB_H__ + +#include +#include + +#ifndef __ASSEMBLY__ + +static inline void arch_kgdb_breakpoint(void) +{ + asm ("brk %0" :: "I" (KDBG_COMPILED_DBG_BRK_IMM)); +} + +extern void kgdb_handle_bus_error(void); +extern int kgdb_fault_expected; + +#endif /* !__ASSEMBLY__ */ + +/* + * gdb is expecting the following registers layout. + * + * General purpose regs: + * r0-r30: 64 bit + * sp,pc : 64 bit + * pstate : 32 bit + * Total: 34 + * FPU regs: + * f0-f31: 128 bit + * Total: 32 + * Extra regs + * fpsr & fpcr: 32 bit + * Total: 2 + * + */ + +#define _GP_REGS 34 +#define _FP_REGS 32 +#define _EXTRA_REGS 2 +/* + * general purpose registers size in bytes. + * pstate is only 4 bytes. subtract 4 bytes + */ +#define GP_REG_BYTES ((_GP_REGS * 8) - 4) +#define DBG_MAX_REG_NUM (_GP_REGS + _FP_REGS + _EXTRA_REGS) + +/* + * Size of I/O buffer for gdb packet. + * considering to hold all register contents, size is set to 1024 + */ + +#define BUFMAX 1024 + +/* + * Number of bytes required for gdb_regs buffer. + * _GP_REGS: 8 bytes, _FP_REGS: 16 bytes and _EXTRA_REGS: 4 bytes each + * pstate reg is only 4 bytes. subtract 4 from size contributed + * by _GP_REGS. + * GDB fails to connect for size beyond this with error + * "'g' packet reply is too long" + */ + +#define NUMREGBYTES (((_GP_REGS * 8) - 4) + (_FP_REGS * 16) + \ + (_EXTRA_REGS * 4)) + +#endif /* __ASM_KGDB_H__ */ diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile index 7b4b564..69613bb 100644 --- a/arch/arm64/kernel/Makefile +++ b/arch/arm64/kernel/Makefile @@ -18,6 +18,7 @@ arm64-obj-$(CONFIG_SMP) += smp.o smp_spin_table.o smp_psci.o arm64-obj-$(CONFIG_HW_PERF_EVENTS) += perf_event.o arm64-obj-$(CONFIG_HAVE_HW_BREAKPOINT)+= hw_breakpoint.o arm64-obj-$(CONFIG_EARLY_PRINTK) += early_printk.o +arm64-obj-$(CONFIG_KGDB) += kgdb.o obj-y += $(arm64-obj-y) vdso/ obj-m += $(arm64-obj-m) diff --git a/arch/arm64/kernel/kgdb.c b/arch/arm64/kernel/kgdb.c new file mode 100644 index 0000000..50cef79 --- /dev/null +++ b/arch/arm64/kernel/kgdb.c @@ -0,0 +1,283 @@ +/* + * AArch64 KGDB support + * + * Based on arch/arm/kernel/kgdb.c + * + * Copyright (C) 2013 Cavium Inc. + * Author: Vijaya Kumar K + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see . + */ + +#include +#include +#include +#include + +struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] = { + { "x0", 8, offsetof(struct pt_regs, regs[0])}, + { "x1", 8, offsetof(struct pt_regs, regs[1])}, + { "x2", 8, offsetof(struct pt_regs, regs[2])}, + { "x3", 8, offsetof(struct pt_regs, regs[3])}, + { "x4", 8, offsetof(struct pt_regs, regs[4])}, + { "x5", 8, offsetof(struct pt_regs, regs[5])}, + { "x6", 8, offsetof(struct pt_regs, regs[6])}, + { "x7", 8, offsetof(struct pt_regs, regs[7])}, + { "x8", 8, offsetof(struct pt_regs, regs[8])}, + { "x9", 8, offsetof(struct pt_regs, regs[9])}, + { "x10", 8, offsetof(struct pt_regs, regs[10])}, + { "x11", 8, offsetof(struct pt_regs, regs[11])}, + { "x12", 8, offsetof(struct pt_regs, regs[12])}, + { "x13", 8, offsetof(struct pt_regs, regs[13])}, + { "x14", 8, offsetof(struct pt_regs, regs[14])}, + { "x15", 8, offsetof(struct pt_regs, regs[15])}, + { "x16", 8, offsetof(struct pt_regs, regs[16])}, + { "x17", 8, offsetof(struct pt_regs, regs[17])}, + { "x18", 8, offsetof(struct pt_regs, regs[18])}, + { "x19", 8, offsetof(struct pt_regs, regs[19])}, + { "x20", 8, offsetof(struct pt_regs, regs[20])}, + { "x21", 8, offsetof(struct pt_regs, regs[21])}, + { "x22", 8, offsetof(struct pt_regs, regs[22])}, + { "x23", 8, offsetof(struct pt_regs, regs[23])}, + { "x24", 8, offsetof(struct pt_regs, regs[24])}, + { "x25", 8, offsetof(struct pt_regs, regs[25])}, + { "x26", 8, offsetof(struct pt_regs, regs[26])}, + { "x27", 8, offsetof(struct pt_regs, regs[27])}, + { "x28", 8, offsetof(struct pt_regs, regs[28])}, + { "x29", 8, offsetof(struct pt_regs, regs[29])}, + { "x30", 8, offsetof(struct pt_regs, regs[30])}, + { "sp", 8, offsetof(struct pt_regs, sp)}, + { "pc", 8, offsetof(struct pt_regs, pc)}, + { "pstate", 4, offsetof(struct pt_regs, pstate)}, + { "v0", 16, -1 }, + { "v1", 16, -1 }, + { "v2", 16, -1 }, + { "v3", 16, -1 }, + { "v4", 16, -1 }, + { "v5", 16, -1 }, + { "v6", 16, -1 }, + { "v7", 16, -1 }, + { "v8", 16, -1 }, + { "v9", 16, -1 }, + { "v10", 16, -1 }, + { "v11", 16, -1 }, + { "v12", 16, -1 }, + { "v13", 16, -1 }, + { "v14", 16, -1 }, + { "v15", 16, -1 }, + { "v16", 16, -1 }, + { "v17", 16, -1 }, + { "v18", 16, -1 }, + { "v19", 16, -1 }, + { "v20", 16, -1 }, + { "v21", 16, -1 }, + { "v22", 16, -1 }, + { "v23", 16, -1 }, + { "v24", 16, -1 }, + { "v25", 16, -1 }, + { "v26", 16, -1 }, + { "v27", 16, -1 }, + { "v28", 16, -1 }, + { "v29", 16, -1 }, + { "v30", 16, -1 }, + { "v31", 16, -1 }, + { "fpsr", 4, -1 }, + { "fpcr", 4, -1 }, +}; + +char *dbg_get_reg(int regno, void *mem, struct pt_regs *regs) +{ + if (regno >= DBG_MAX_REG_NUM || regno < 0) + return NULL; + + if (dbg_reg_def[regno].offset != -1) + memcpy(mem, (void *)regs + dbg_reg_def[regno].offset, + dbg_reg_def[regno].size); + else + memset(mem, 0, dbg_reg_def[regno].size); + return dbg_reg_def[regno].name; +} + +int dbg_set_reg(int regno, void *mem, struct pt_regs *regs) +{ + if (regno >= DBG_MAX_REG_NUM || regno < 0) + return -EINVAL; + + if (dbg_reg_def[regno].offset != -1) + memcpy((void *)regs + dbg_reg_def[regno].offset, mem, + dbg_reg_def[regno].size); + return 0; +} + +void +sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *task) +{ + struct pt_regs *thread_regs; + + /* Initialize to zero */ + memset((char *)gdb_regs, 0, NUMREGBYTES); + thread_regs = task_pt_regs(task); + memcpy((void *)gdb_regs, (void *)thread_regs->regs, GP_REG_BYTES); +} + +void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc) +{ + regs->pc = pc; +} + +static int compiled_break; + +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]) { + case 'D': + case 'k': + case 'c': + /* + * Packet D (Detach), k (kill) & c (Continue) requires + * to continue executing. Set pc to required address. + * Try to read optional parameter, pc unchanged if no parm. + * If this was a compiled breakpoint, we need to move + * to the next instruction or 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); + + compiled_break = 0; + + err = 0; + break; + default: + err = -1; + } + return err; +} + +static int kgdb_brk_fn(struct pt_regs *regs, unsigned int esr) +{ + kgdb_handle_exception(1, SIGTRAP, 0, regs); + return 0; +} + +static int kgdb_compiled_brk_fn(struct pt_regs *regs, unsigned int esr) +{ + compiled_break = 1; + 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), + .fn = kgdb_brk_fn +}; + +static struct break_hook kgdb_compiled_brkpt_hook = { + .esr_mask = 0xffffffff, + .esr_val = DBG_ESR_VAL_BRK(KDBG_COMPILED_DBG_BRK_IMM), + .fn = kgdb_compiled_brk_fn +}; + +static void kgdb_call_nmi_hook(void *ignored) +{ + kgdb_nmicallback(raw_smp_processor_id(), get_irq_regs()); +} + +void kgdb_roundup_cpus(unsigned long flags) +{ + local_irq_enable(); + smp_call_function(kgdb_call_nmi_hook, NULL, 0); + local_irq_disable(); +} + +static int __kgdb_notify(struct die_args *args, unsigned long cmd) +{ + struct pt_regs *regs = args->regs; + + if (kgdb_handle_exception(1, args->signr, cmd, regs)) + return NOTIFY_DONE; + return NOTIFY_STOP; +} + +static int +kgdb_notify(struct notifier_block *self, unsigned long cmd, void *ptr) +{ + unsigned long flags; + int ret; + + local_irq_save(flags); + ret = __kgdb_notify(ptr, cmd); + local_irq_restore(flags); + + return ret; +} + +static struct notifier_block kgdb_notifier = { + .notifier_call = kgdb_notify, + .priority = -INT_MAX, +}; + +/* + * kgdb_arch_init - Perform any architecture specific initalization. + * This function will handle the initalization of any architecture + * specific callbacks. + */ +int kgdb_arch_init(void) +{ + int ret = register_die_notifier(&kgdb_notifier); + + if (ret != 0) + return ret; + + register_break_hook(&kgdb_brkpt_hook); + register_break_hook(&kgdb_compiled_brkpt_hook); + + return 0; +} + +/* + * kgdb_arch_exit - Perform any architecture specific uninitalization. + * This function will handle the uninitalization of any architecture + * specific callbacks, for dynamic registration and unregistration. + */ +void kgdb_arch_exit(void) +{ + unregister_break_hook(&kgdb_brkpt_hook); + unregister_break_hook(&kgdb_compiled_brkpt_hook); + unregister_die_notifier(&kgdb_notifier); +} + +/* + * ARM instructions are always in LE. + * Break instruction is encoded in LE format + */ +struct kgdb_arch arch_kgdb_ops = { + .gdb_bpt_instr = { + KGDB_DYN_BRK_INS_BYTE0, + KGDB_DYN_BRK_INS_BYTE1, + KGDB_DYN_BRK_INS_BYTE2, + KGDB_DYN_BRK_INS_BYTE3, + } +};