From patchwork Mon Aug 20 14:47:28 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Anton Vorontsov X-Patchwork-Id: 10813 Return-Path: X-Original-To: patchwork@peony.canonical.com Delivered-To: patchwork@peony.canonical.com Received: from fiordland.canonical.com (fiordland.canonical.com [91.189.94.145]) by peony.canonical.com (Postfix) with ESMTP id 95A0823E56 for ; Mon, 20 Aug 2012 14:50:20 +0000 (UTC) Received: from mail-gg0-f180.google.com (mail-gg0-f180.google.com [209.85.161.180]) by fiordland.canonical.com (Postfix) with ESMTP id 6754FA18B6B for ; Mon, 20 Aug 2012 14:50:14 +0000 (UTC) Received: by mail-gg0-f180.google.com with SMTP id i2so5358432ggm.11 for ; Mon, 20 Aug 2012 07:50:20 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=x-forwarded-to:x-forwarded-for:delivered-to:received-spf:from:to:cc :subject:date:message-id:x-mailer:in-reply-to:references :mime-version:content-type:content-transfer-encoding :x-gm-message-state; bh=hQwHQ9a2+FU5sVJ6UrYXQCHt/s9GFZxfZ56zG5p953w=; b=VNh9sLurR+SM2e7L4fSSER5c7GsND16hNn4qLCSPDNoN9sxasuLrN5f0zHlURpOa4e lrO6ENlgPS68fON/CrWe9avO0771Shzqsx8NzqftZ+a8hFn1NNCxDoBTUsdndkFL3stm DfDDqhkRTcLIB5NmiMGqE/YOmuHRcE7KMYxnKUY2/8OPlyX06oIJBEE849i2EcLAkHmG m5LqAIL4ehpoxooPRHEJN25vKePfbVSxMfTN3snM+jc4JfYNhrmQDIyPm750b82w9QMD NHd0zGu273SVtbq4X5X6N+WErA6Kw2Zgug3VA8vpQDbGq4sWxGnVOvt1YFIQeWcPIhk1 Wqig== Received: by 10.50.187.138 with SMTP id fs10mr9954310igc.43.1345474219569; Mon, 20 Aug 2012 07:50:19 -0700 (PDT) X-Forwarded-To: linaro-patchwork@canonical.com X-Forwarded-For: patch@linaro.org linaro-patchwork@canonical.com Delivered-To: patches@linaro.org Received: by 10.50.184.232 with SMTP id ex8csp87734igc; Mon, 20 Aug 2012 07:50:18 -0700 (PDT) Received: by 10.66.84.6 with SMTP id u6mr29952816pay.75.1345474218673; Mon, 20 Aug 2012 07:50:18 -0700 (PDT) Received: from mail-pz0-f50.google.com (mail-pz0-f50.google.com [209.85.210.50]) by mx.google.com with ESMTPS id qt3si26954278pbc.353.2012.08.20.07.50.18 (version=TLSv1/SSLv3 cipher=OTHER); Mon, 20 Aug 2012 07:50:18 -0700 (PDT) Received-SPF: neutral (google.com: 209.85.210.50 is neither permitted nor denied by best guess record for domain of anton.vorontsov@linaro.org) client-ip=209.85.210.50; Authentication-Results: mx.google.com; spf=neutral (google.com: 209.85.210.50 is neither permitted nor denied by best guess record for domain of anton.vorontsov@linaro.org) smtp.mail=anton.vorontsov@linaro.org Received: by mail-pz0-f50.google.com with SMTP id e7so2499989dad.37 for ; Mon, 20 Aug 2012 07:50:18 -0700 (PDT) Received: by 10.68.234.99 with SMTP id ud3mr34879215pbc.166.1345474217993; Mon, 20 Aug 2012 07:50:17 -0700 (PDT) Received: from localhost (c-71-204-165-222.hsd1.ca.comcast.net. [71.204.165.222]) by mx.google.com with ESMTPS id qx8sm11225377pbc.63.2012.08.20.07.50.16 (version=TLSv1/SSLv3 cipher=OTHER); Mon, 20 Aug 2012 07:50:17 -0700 (PDT) From: Anton Vorontsov To: Russell King , Jason Wessel , Greg Kroah-Hartman , Alan Cox Cc: =?UTF-8?q?Arve=20Hj=C3=B8nnev=C3=A5g?= , Colin Cross , John Stultz , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linaro-kernel@lists.linaro.org, patches@linaro.org, kernel-team@android.com, kgdb-bugreport@lists.sourceforge.net Subject: =?UTF-8?q?=5BPATCH=2010/12=5D=20ARM=3A=20Add=20KGDB/KDB=20FIQ=20debugger=20generic=20code?= Date: Mon, 20 Aug 2012 07:47:28 -0700 Message-Id: <1345474050-8339-10-git-send-email-anton.vorontsov@linaro.org> X-Mailer: git-send-email 1.7.11.5 In-Reply-To: <20120820144449.GA32560@lizard> References: <20120820144449.GA32560@lizard> MIME-Version: 1.0 X-Gm-Message-State: ALoCoQl2OTJBiDI9f6EfKYWmek8+EPygLlcPSQwn+bhcJ3ciCiq6D+lARGb4G3XMGE2u72+9Q477 The FIQ debugger may be used to debug situations when the kernel stuck in uninterruptable sections, e.g. the kernel infinitely loops or deadlocked in an interrupt or with interrupts disabled. By default KGDB FIQ is disabled in runtime, but can be enabled with kgdb_fiq.enable=1 kernel command line option. Signed-off-by: Anton Vorontsov --- arch/arm/Kconfig | 18 ++++++++ arch/arm/include/asm/kgdb.h | 8 ++++ arch/arm/kernel/Makefile | 1 + arch/arm/kernel/kgdb_fiq.c | 99 ++++++++++++++++++++++++++++++++++++++++ arch/arm/kernel/kgdb_fiq_entry.S | 87 +++++++++++++++++++++++++++++++++++ 5 files changed, 213 insertions(+) create mode 100644 arch/arm/kernel/kgdb_fiq.c create mode 100644 arch/arm/kernel/kgdb_fiq_entry.S diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 6d6e18f..c978c74 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -171,6 +171,24 @@ config GENERIC_ISA_DMA config FIQ bool +config ARCH_MIGHT_HAVE_KGDB_FIQ + bool + +config KGDB_FIQ + bool "KGDB/KDB FIQ debugger" + depends on KGDB_KDB && ARCH_MIGHT_HAVE_KGDB_FIQ && !THUMB2_KERNEL + select FIQ + help + The FIQ debugger may be used to debug situations when the + kernel stuck in uninterruptable sections, e.g. the kernel + infinitely loops or deadlocked in an interrupt or with + interrupts disabled. + + By default KGDB FIQ is disabled in runtime, but can be + enabled with kgdb_fiq.enable=1 kernel command line option. + + If unsure, say N. + config NEED_RET_TO_USER bool diff --git a/arch/arm/include/asm/kgdb.h b/arch/arm/include/asm/kgdb.h index 48066ce..807e547 100644 --- a/arch/arm/include/asm/kgdb.h +++ b/arch/arm/include/asm/kgdb.h @@ -11,6 +11,8 @@ #define __ARM_KGDB_H__ #include +#include +#include /* * GDB assumes that we're a user process being debugged, so @@ -47,6 +49,12 @@ static inline void arch_kgdb_breakpoint(void) extern void kgdb_handle_bus_error(void); extern int kgdb_fault_expected; +extern char kgdb_fiq_handler; +extern char kgdb_fiq_handler_end; +asmlinkage void __exception_irq_entry kgdb_fiq_do_handle(struct pt_regs *regs); +extern int __init kgdb_register_fiq(unsigned int mach_kgdb_fiq, + void (*mach_kgdb_enable_fiq)(unsigned int irq, bool on), + bool (*mach_is_kgdb_fiq)(unsigned int irq)); #endif /* !__ASSEMBLY__ */ /* diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile index 7ad2d5c..5aa079b 100644 --- a/arch/arm/kernel/Makefile +++ b/arch/arm/kernel/Makefile @@ -56,6 +56,7 @@ obj-$(CONFIG_ATAGS_PROC) += atags.o obj-$(CONFIG_OABI_COMPAT) += sys_oabi-compat.o obj-$(CONFIG_ARM_THUMBEE) += thumbee.o obj-$(CONFIG_KGDB) += kgdb.o +obj-$(CONFIG_KGDB_FIQ) += kgdb_fiq_entry.o kgdb_fiq.o obj-$(CONFIG_ARM_UNWIND) += unwind.o obj-$(CONFIG_HAVE_TCM) += tcm.o obj-$(CONFIG_OF) += devtree.o diff --git a/arch/arm/kernel/kgdb_fiq.c b/arch/arm/kernel/kgdb_fiq.c new file mode 100644 index 0000000..8443af1 --- /dev/null +++ b/arch/arm/kernel/kgdb_fiq.c @@ -0,0 +1,99 @@ +/* + * KGDB FIQ + * + * Copyright 2010 Google, Inc. + * Arve Hjønnevåg + * Colin Cross + * Copyright 2012 Linaro Ltd. + * Anton Vorontsov + * + * 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. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +static int kgdb_fiq_enabled; +module_param_named(enable, kgdb_fiq_enabled, int, 0600); +MODULE_PARM_DESC(enable, "set to 1 to enable FIQ KGDB"); + +static unsigned int kgdb_fiq; +static bool (*is_kgdb_fiq)(unsigned int irq); + +asmlinkage void __exception_irq_entry kgdb_fiq_do_handle(struct pt_regs *regs) +{ + if (!is_kgdb_fiq(kgdb_fiq)) + return; + if (!kgdb_nmi_poll_knock()) + return; + + nmi_enter(); + kgdb_handle_exception(1, 0, 0, regs); + nmi_exit(); +} + +static struct fiq_handler kgdb_fiq_desc = { + .name = "kgdb", +}; + +static long kgdb_fiq_setup_stack(void *info) +{ + struct pt_regs regs; + + regs.ARM_sp = __get_free_pages(GFP_KERNEL, THREAD_SIZE_ORDER) + + THREAD_START_SP; + WARN_ON(!regs.ARM_sp); + + set_fiq_regs(®s); + return 0; +} + +static void (*kgdb_enable_fiq)(unsigned int irq, bool on); + +void kgdb_arch_enable_nmi(bool on) +{ + if (!kgdb_enable_fiq) + return; + kgdb_enable_fiq(kgdb_fiq, on); +} + +int __init kgdb_register_fiq(unsigned int mach_kgdb_fiq, + void (*mach_kgdb_enable_fiq)(unsigned int irq, bool on), + bool (*mach_is_kgdb_fiq)(unsigned int irq)) +{ + int err; + int cpu; + + if (!kgdb_fiq_enabled) + return -ENODEV; + if (kgdb_fiq) + return -EBUSY; + + kgdb_fiq = mach_kgdb_fiq; + kgdb_enable_fiq = mach_kgdb_enable_fiq; + is_kgdb_fiq = mach_is_kgdb_fiq; + + err = claim_fiq(&kgdb_fiq_desc); + if (err) { + pr_warn("%s: unable to claim fiq", __func__); + return err; + } + + for_each_possible_cpu(cpu) + work_on_cpu(cpu, kgdb_fiq_setup_stack, NULL); + + set_fiq_handler(&kgdb_fiq_handler, + &kgdb_fiq_handler_end - &kgdb_fiq_handler); + + return 0; +} diff --git a/arch/arm/kernel/kgdb_fiq_entry.S b/arch/arm/kernel/kgdb_fiq_entry.S new file mode 100644 index 0000000..d6becca --- /dev/null +++ b/arch/arm/kernel/kgdb_fiq_entry.S @@ -0,0 +1,87 @@ +/* + * KGDB FIQ entry + * + * Copyright 1996,1997,1998 Russell King. + * Copyright 2012 Linaro Ltd. + * Anton Vorontsov + * + * 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. + */ + +#include +#include +#include +#include +#include "entry-header.S" + + .text + +@ This is needed for usr_entry/alignment_trap +.LCcralign: + .long cr_alignment +.LCdohandle: + .long kgdb_fiq_do_handle + + .macro fiq_handler + ldr r1, =.LCdohandle + mov r0, sp + adr lr, BSYM(9997f) + ldr pc, [r1] +9997: + .endm + + .align 5 +__fiq_svc: + svc_entry + fiq_handler + mov r0, sp + ldmib r0, {r1 - r14} + msr cpsr_c, #FIQ_MODE | PSR_I_BIT | PSR_F_BIT + add r8, r0, #S_PC + ldr r9, [r0, #S_PSR] + msr spsr_cxsf, r9 + ldr r0, [r0, #S_R0] + ldmia r8, {pc}^ + + UNWIND(.fnend ) +ENDPROC(__fiq_svc) + .ltorg + + .align 5 +__fiq_usr: + usr_entry + kuser_cmpxchg_check + fiq_handler + get_thread_info tsk + mov why, #0 + b ret_to_user_from_irq + UNWIND(.fnend ) +ENDPROC(__fiq_usr) + .ltorg + + .global kgdb_fiq_handler +kgdb_fiq_handler: + + vector_stub fiq, FIQ_MODE, 4 + + .long __fiq_usr @ 0 (USR_26 / USR_32) + .long __fiq_svc @ 1 (FIQ_26 / FIQ_32) + .long __fiq_svc @ 2 (IRQ_26 / IRQ_32) + .long __fiq_svc @ 3 (SVC_26 / SVC_32) + .long __fiq_svc @ 4 + .long __fiq_svc @ 5 + .long __fiq_svc @ 6 + .long __fiq_svc @ 7 + .long __fiq_svc @ 8 + .long __fiq_svc @ 9 + .long __fiq_svc @ a + .long __fiq_svc @ b + .long __fiq_svc @ c + .long __fiq_svc @ d + .long __fiq_svc @ e + .long __fiq_svc @ f + + .global kgdb_fiq_handler_end +kgdb_fiq_handler_end: