* [PATCH 6/7] kgdb-light-v10: move the kgdb core and arch implementation
2008-02-15 20:55 ` [PATCH 5/7] kgdb-light-v10: x86 HW breakpoints Jason Wessel
@ 2008-02-15 20:55 ` Jason Wessel
2008-02-15 20:55 ` [PATCH 7/7] kgdb-light-v10: build core and arch pieces as a kernel module Jason Wessel
0 siblings, 1 reply; 8+ messages in thread
From: Jason Wessel @ 2008-02-15 20:55 UTC (permalink / raw)
To: mingo; +Cc: linux-kernel, Jason Wessel
Simply relocate the arch specific and kgdb core implementation files
so as to build as a module in a future patch.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
---
arch/x86/kernel/Makefile | 4 +-
arch/x86/kernel/kgdb-x86.c | 567 +++++++++++++++
arch/x86/kernel/kgdb.c | 567 ---------------
kernel/Makefile | 1 -
kernel/kgdb.c | 1680 --------------------------------------------
lib/kgdb.c | 1680 ++++++++++++++++++++++++++++++++++++++++++++
6 files changed, 2250 insertions(+), 2249 deletions(-)
create mode 100644 arch/x86/kernel/kgdb-x86.c
delete mode 100644 arch/x86/kernel/kgdb.c
delete mode 100644 kernel/kgdb.c
create mode 100644 lib/kgdb.c
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index 4cd39cd..2e733b1 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -58,7 +58,6 @@ obj-$(CONFIG_MODULES) += module_$(BITS).o
obj-$(CONFIG_ACPI_SRAT) += srat_32.o
obj-$(CONFIG_EFI) += efi.o efi_$(BITS).o efi_stub_$(BITS).o
obj-$(CONFIG_DOUBLEFAULT) += doublefault_32.o
-obj-$(CONFIG_KGDB) += kgdb.o
obj-$(CONFIG_VM86) += vm86_32.o
obj-$(CONFIG_EARLY_PRINTK) += early_printk.o
@@ -79,6 +78,9 @@ endif
obj-$(CONFIG_SCx200) += scx200.o
scx200-y += scx200_32.o
+kgdb-objs := ../../../lib/kgdb.o kgdb-x86.o
+obj-$(CONFIG_KGDB) += kgdb.o
+
###
# 64 bit specific files
ifeq ($(CONFIG_X86_64),y)
diff --git a/arch/x86/kernel/kgdb-x86.c b/arch/x86/kernel/kgdb-x86.c
new file mode 100644
index 0000000..88bfa45
--- /dev/null
+++ b/arch/x86/kernel/kgdb-x86.c
@@ -0,0 +1,567 @@
+/*
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2, or (at your option) any
+ * later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ */
+
+/*
+ * Copyright (C) 2004 Amit S. Kale <amitkale@linsyssoft.com>
+ * Copyright (C) 2000-2001 VERITAS Software Corporation.
+ * Copyright (C) 2002 Andi Kleen, SuSE Labs
+ * Copyright (C) 2004 LinSysSoft Technologies Pvt. Ltd.
+ * Copyright (C) 2007 MontaVista Software, Inc.
+ * Copyright (C) 2007-2008 Jason Wessel, Wind River Systems, Inc.
+ */
+/****************************************************************************
+ * Contributor: Lake Stevens Instrument Division$
+ * Written by: Glenn Engel $
+ * Updated by: Amit Kale<akale@veritas.com>
+ * Updated by: Tom Rini <trini@kernel.crashing.org>
+ * Updated by: Jason Wessel <jason.wessel@windriver.com>
+ * Modified for 386 by Jim Kingdon, Cygnus Support.
+ * Origianl kgdb, compatibility with 2.1.xx kernel by
+ * David Grothe <dave@gcom.com>
+ * Integrated into 2.2.5 kernel by Tigran Aivazian <tigran@sco.com>
+ * X86_64 changes from Andi Kleen's patch merged by Jim Houston
+ */
+#include <linux/spinlock.h>
+#include <linux/kdebug.h>
+#include <linux/string.h>
+#include <linux/kernel.h>
+#include <linux/ptrace.h>
+#include <linux/sched.h>
+#include <linux/delay.h>
+#include <linux/kgdb.h>
+#include <linux/init.h>
+#include <linux/smp.h>
+#include <linux/nmi.h>
+
+#include <asm/apicdef.h>
+#include <asm/system.h>
+
+#ifdef CONFIG_X86_32
+# include <mach_ipi.h>
+#else
+# include <asm/mach_apic.h>
+#endif
+
+/*
+ * Put the error code here just in case the user cares:
+ */
+static int gdb_x86errcode;
+
+/*
+ * Likewise, the vector number here (since GDB only gets the signal
+ * number through the usual means, and that's not very specific):
+ */
+static int gdb_x86vector = -1;
+
+/**
+ * pt_regs_to_gdb_regs - Convert ptrace regs to GDB regs
+ * @gdb_regs: A pointer to hold the registers in the order GDB wants.
+ * @regs: The &struct pt_regs of the current process.
+ *
+ * Convert the pt_regs in @regs into the format for registers that
+ * GDB expects, stored in @gdb_regs.
+ */
+void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs)
+{
+ gdb_regs[GDB_AX] = regs->ax;
+ gdb_regs[GDB_BX] = regs->bx;
+ gdb_regs[GDB_CX] = regs->cx;
+ gdb_regs[GDB_DX] = regs->dx;
+ gdb_regs[GDB_SI] = regs->si;
+ gdb_regs[GDB_DI] = regs->di;
+ gdb_regs[GDB_BP] = regs->bp;
+ gdb_regs[GDB_PS] = regs->flags;
+ gdb_regs[GDB_PC] = regs->ip;
+#ifdef CONFIG_X86_32
+ gdb_regs[GDB_DS] = regs->ds;
+ gdb_regs[GDB_ES] = regs->es;
+ gdb_regs[GDB_CS] = regs->cs;
+ gdb_regs[GDB_SS] = __KERNEL_DS;
+ gdb_regs[GDB_FS] = 0xFFFF;
+ gdb_regs[GDB_GS] = 0xFFFF;
+#else
+ gdb_regs[GDB_R8] = regs->r8;
+ gdb_regs[GDB_R9] = regs->r9;
+ gdb_regs[GDB_R10] = regs->r10;
+ gdb_regs[GDB_R11] = regs->r11;
+ gdb_regs[GDB_R12] = regs->r12;
+ gdb_regs[GDB_R13] = regs->r13;
+ gdb_regs[GDB_R14] = regs->r14;
+ gdb_regs[GDB_R15] = regs->r15;
+#endif
+ gdb_regs[GDB_SP] = regs->sp;
+}
+
+/**
+ * sleeping_thread_to_gdb_regs - Convert ptrace regs to GDB regs
+ * @gdb_regs: A pointer to hold the registers in the order GDB wants.
+ * @p: The &struct task_struct of the desired process.
+ *
+ * Convert the register values of the sleeping process in @p to
+ * the format that GDB expects.
+ * This function is called when kgdb does not have access to the
+ * &struct pt_regs and therefore it should fill the gdb registers
+ * @gdb_regs with what has been saved in &struct thread_struct
+ * thread field during switch_to.
+ */
+void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p)
+{
+ gdb_regs[GDB_AX] = 0;
+ gdb_regs[GDB_BX] = 0;
+ gdb_regs[GDB_CX] = 0;
+ gdb_regs[GDB_DX] = 0;
+ gdb_regs[GDB_SI] = 0;
+ gdb_regs[GDB_DI] = 0;
+ gdb_regs[GDB_BP] = *(unsigned long *)p->thread.sp;
+#ifdef CONFIG_X86_32
+ gdb_regs[GDB_DS] = __KERNEL_DS;
+ gdb_regs[GDB_ES] = __KERNEL_DS;
+ gdb_regs[GDB_PS] = 0;
+ gdb_regs[GDB_CS] = __KERNEL_CS;
+ gdb_regs[GDB_PC] = p->thread.ip;
+ gdb_regs[GDB_SS] = __KERNEL_DS;
+ gdb_regs[GDB_FS] = 0xFFFF;
+ gdb_regs[GDB_GS] = 0xFFFF;
+#else
+ gdb_regs[GDB_PS] = *(unsigned long *)(p->thread.sp + 8);
+ gdb_regs[GDB_PC] = 0;
+ gdb_regs[GDB_R8] = 0;
+ gdb_regs[GDB_R9] = 0;
+ gdb_regs[GDB_R10] = 0;
+ gdb_regs[GDB_R11] = 0;
+ gdb_regs[GDB_R12] = 0;
+ gdb_regs[GDB_R13] = 0;
+ gdb_regs[GDB_R14] = 0;
+ gdb_regs[GDB_R15] = 0;
+#endif
+ gdb_regs[GDB_SP] = p->thread.sp;
+}
+
+/**
+ * gdb_regs_to_pt_regs - Convert GDB regs to ptrace regs.
+ * @gdb_regs: A pointer to hold the registers we've received from GDB.
+ * @regs: A pointer to a &struct pt_regs to hold these values in.
+ *
+ * Convert the GDB regs in @gdb_regs into the pt_regs, and store them
+ * in @regs.
+ */
+void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs)
+{
+ regs->ax = gdb_regs[GDB_AX];
+ regs->bx = gdb_regs[GDB_BX];
+ regs->cx = gdb_regs[GDB_CX];
+ regs->dx = gdb_regs[GDB_DX];
+ regs->si = gdb_regs[GDB_SI];
+ regs->di = gdb_regs[GDB_DI];
+ regs->bp = gdb_regs[GDB_BP];
+ regs->flags = gdb_regs[GDB_PS];
+ regs->ip = gdb_regs[GDB_PC];
+#ifdef CONFIG_X86_32
+ regs->ds = gdb_regs[GDB_DS];
+ regs->es = gdb_regs[GDB_ES];
+ regs->cs = gdb_regs[GDB_CS];
+#else
+ regs->r8 = gdb_regs[GDB_R8];
+ regs->r9 = gdb_regs[GDB_R9];
+ regs->r10 = gdb_regs[GDB_R10];
+ regs->r11 = gdb_regs[GDB_R11];
+ regs->r12 = gdb_regs[GDB_R12];
+ regs->r13 = gdb_regs[GDB_R13];
+ regs->r14 = gdb_regs[GDB_R14];
+ regs->r15 = gdb_regs[GDB_R15];
+#endif
+}
+
+static struct hw_breakpoint {
+ unsigned enabled;
+ unsigned type;
+ unsigned len;
+ unsigned long addr;
+} breakinfo[4];
+
+static void kgdb_correct_hw_break(void)
+{
+ unsigned long dr7;
+ int correctit = 0;
+ int breakbit;
+ int breakno;
+
+ get_debugreg(dr7, 7);
+ for (breakno = 0; breakno < 4; breakno++) {
+ breakbit = 2 << (breakno << 1);
+ if (!(dr7 & breakbit) && breakinfo[breakno].enabled) {
+ correctit = 1;
+ dr7 |= breakbit;
+ dr7 &= ~(0xf0000 << (breakno << 2));
+ dr7 |= ((breakinfo[breakno].len << 2) |
+ breakinfo[breakno].type) <<
+ ((breakno << 2) + 16);
+ if (breakno >= 0 && breakno <= 3)
+ set_debugreg(breakinfo[breakno].addr, breakno);
+
+ } else {
+ if ((dr7 & breakbit) && !breakinfo[breakno].enabled) {
+ correctit = 1;
+ dr7 &= ~breakbit;
+ dr7 &= ~(0xf0000 << (breakno << 2));
+ }
+ }
+ }
+ if (correctit)
+ set_debugreg(dr7, 7);
+}
+
+static int
+kgdb_remove_hw_break(unsigned long addr, int len, enum kgdb_bptype bptype)
+{
+ int i;
+
+ for (i = 0; i < 4; i++)
+ if (breakinfo[i].addr == addr && breakinfo[i].enabled)
+ break;
+ if (i == 4)
+ return -1;
+
+ breakinfo[i].enabled = 0;
+
+ return 0;
+}
+
+static void kgdb_remove_all_hw_break(void)
+{
+ int i;
+
+ for (i = 0; i < 4; i++)
+ memset(&breakinfo[i], 0, sizeof(struct hw_breakpoint));
+}
+
+static int
+kgdb_set_hw_break(unsigned long addr, int len, enum kgdb_bptype bptype)
+{
+ unsigned type;
+ int i;
+
+ for (i = 0; i < 4; i++)
+ if (!breakinfo[i].enabled)
+ break;
+ if (i == 4)
+ return -1;
+
+ switch (bptype) {
+ case BP_HARDWARE_BREAKPOINT:
+ type = 0;
+ len = 1;
+ break;
+ case BP_WRITE_WATCHPOINT:
+ type = 1;
+ break;
+ case BP_ACCESS_WATCHPOINT:
+ type = 3;
+ break;
+ default:
+ return -1;
+ }
+
+ if (len == 1 || len == 2 || len == 4)
+ breakinfo[i].len = len - 1;
+ else
+ return -1;
+
+ breakinfo[i].enabled = 1;
+ breakinfo[i].addr = addr;
+ breakinfo[i].type = type;
+
+ return 0;
+}
+
+/**
+ * kgdb_disable_hw_debug - Disable hardware debugging while we in kgdb.
+ * @regs: Current &struct pt_regs.
+ *
+ * This function will be called if the particular architecture must
+ * disable hardware debugging while it is processing gdb packets or
+ * handling exception.
+ */
+void kgdb_disable_hw_debug(struct pt_regs *regs)
+{
+ /* Disable hardware debugging while we are in kgdb: */
+ set_debugreg(0UL, 7);
+}
+
+/**
+ * kgdb_post_primary_code - Save error vector/code numbers.
+ * @regs: Original pt_regs.
+ * @e_vector: Original error vector.
+ * @err_code: Original error code.
+ *
+ * This is needed on architectures which support SMP and KGDB.
+ * This function is called after all the slave cpus have been put
+ * to a know spin state and the primary CPU has control over KGDB.
+ */
+void kgdb_post_primary_code(struct pt_regs *regs, int e_vector, int err_code)
+{
+ /* primary processor is completely in the debugger */
+ gdb_x86vector = e_vector;
+ gdb_x86errcode = err_code;
+}
+
+#ifdef CONFIG_SMP
+/**
+ * kgdb_roundup_cpus - Get other CPUs into a holding pattern
+ * @flags: Current IRQ state
+ *
+ * On SMP systems, we need to get the attention of the other CPUs
+ * and get them be in a known state. This should do what is needed
+ * to get the other CPUs to call kgdb_wait(). Note that on some arches,
+ * the NMI approach is not used for rounding up all the CPUs. For example,
+ * in case of MIPS, smp_call_function() is used to roundup CPUs. In
+ * this case, we have to make sure that interrupts are enabled before
+ * calling smp_call_function(). The argument to this function is
+ * the flags that will be used when restoring the interrupts. There is
+ * local_irq_save() call before kgdb_roundup_cpus().
+ *
+ * On non-SMP systems, this is not called.
+ */
+void kgdb_roundup_cpus(unsigned long flags)
+{
+ send_IPI_allbutself(APIC_DM_NMI);
+}
+#endif
+
+/**
+ * kgdb_arch_handle_exception - Handle architecture specific GDB packets.
+ * @vector: The error vector of the exception that happened.
+ * @signo: The signal number of the exception that happened.
+ * @err_code: The error code of the exception that happened.
+ * @remcom_in_buffer: The buffer of the packet we have read.
+ * @remcom_out_buffer: The buffer of %BUFMAX bytes to write a packet into.
+ * @regs: The &struct pt_regs of the current process.
+ *
+ * This function MUST handle the 'c' and 's' command packets,
+ * as well packets to set / remove a hardware breakpoint, if used.
+ * If there are additional packets which the hardware needs to handle,
+ * they are handled here. The code should return -1 if it wants to
+ * process more packets, and a %0 or %1 if it wants to exit from the
+ * kgdb callback.
+ */
+int kgdb_arch_handle_exception(int e_vector, int signo, int err_code,
+ char *remcomInBuffer, char *remcomOutBuffer,
+ struct pt_regs *linux_regs)
+{
+ unsigned long addr;
+ unsigned long dr6;
+ char *ptr;
+ int newPC;
+
+ switch (remcomInBuffer[0]) {
+ case 'c':
+ case 's':
+ /* try to read optional parameter, pc unchanged if no parm */
+ ptr = &remcomInBuffer[1];
+ if (kgdb_hex2long(&ptr, &addr))
+ linux_regs->ip = addr;
+ newPC = linux_regs->ip;
+
+ /* clear the trace bit */
+ linux_regs->flags &= ~TF_MASK;
+ atomic_set(&kgdb_cpu_doing_single_step, -1);
+
+ /* set the trace bit if we're stepping */
+ if (remcomInBuffer[0] == 's') {
+ linux_regs->flags |= TF_MASK;
+ kgdb_single_step = 1;
+ if (kgdb_contthread) {
+ atomic_set(&kgdb_cpu_doing_single_step,
+ raw_smp_processor_id());
+ }
+ }
+
+ get_debugreg(dr6, 6);
+ if (!(dr6 & 0x4000)) {
+ int breakno;
+
+ for (breakno = 0; breakno < 4; breakno++) {
+ if (dr6 & (1 << breakno) &&
+ breakinfo[breakno].type == 0) {
+ /* Set restore flag: */
+ linux_regs->flags |= X86_EFLAGS_RF;
+ break;
+ }
+ }
+ }
+ set_debugreg(0UL, 6);
+ kgdb_correct_hw_break();
+
+ return 0;
+ }
+
+ /* this means that we do not want to exit from the handler: */
+ return -1;
+}
+
+static inline int
+single_step_cont(struct pt_regs *regs, struct die_args *args)
+{
+ /*
+ * Single step exception from kernel space to user space so
+ * eat the exception and continue the process:
+ */
+ printk(KERN_ERR "KGDB: trap/step from kernel to user space, "
+ "resuming...\n");
+ kgdb_arch_handle_exception(args->trapnr, args->signr,
+ args->err, "c", "", regs);
+
+ return NOTIFY_STOP;
+}
+
+static int was_in_debug_nmi[NR_CPUS];
+
+static int __kgdb_notify(struct die_args *args, unsigned long cmd)
+{
+ struct pt_regs *regs = args->regs;
+
+ switch (cmd) {
+ case DIE_NMI:
+ if (atomic_read(&kgdb_active) != -1) {
+ /* KGDB CPU roundup */
+ kgdb_nmicallback(raw_smp_processor_id(), regs);
+ was_in_debug_nmi[raw_smp_processor_id()] = 1;
+ touch_nmi_watchdog();
+ return NOTIFY_STOP;
+ }
+ return NOTIFY_DONE;
+
+ case DIE_NMI_IPI:
+ if (atomic_read(&kgdb_active) != -1) {
+ /* KGDB CPU roundup */
+ kgdb_nmicallback(raw_smp_processor_id(), regs);
+ was_in_debug_nmi[raw_smp_processor_id()] = 1;
+ touch_nmi_watchdog();
+ }
+ return NOTIFY_DONE;
+
+ case DIE_NMIUNKNOWN:
+ if (was_in_debug_nmi[raw_smp_processor_id()]) {
+ was_in_debug_nmi[raw_smp_processor_id()] = 0;
+ return NOTIFY_STOP;
+ }
+ return NOTIFY_DONE;
+
+ case DIE_NMIWATCHDOG:
+ if (atomic_read(&kgdb_active) != -1) {
+ /* KGDB CPU roundup: */
+ kgdb_nmicallback(raw_smp_processor_id(), regs);
+ return NOTIFY_STOP;
+ }
+ /* Enter debugger: */
+ break;
+
+ case DIE_DEBUG:
+ if (atomic_read(&kgdb_cpu_doing_single_step) ==
+ raw_smp_processor_id() &&
+ user_mode(regs))
+ return single_step_cont(regs, args);
+ /* fall through */
+ default:
+ if (user_mode(regs))
+ return NOTIFY_DONE;
+ }
+
+ if (kgdb_handle_exception(args->trapnr, args->signr, args->err, 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,
+
+ /*
+ * Lowest-prio notifier priority, we want to be notified last:
+ */
+ .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)
+{
+ return register_die_notifier(&kgdb_notifier);
+}
+
+/**
+ * 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_die_notifier(&kgdb_notifier);
+}
+
+/**
+ *
+ * kgdb_skipexception - Bail of of KGDB when we've been triggered.
+ * @exception: Exception vector number
+ * @regs: Current &struct pt_regs.
+ *
+ * On some architectures we need to skip a breakpoint exception when
+ * it occurs after a breakpoint has been removed.
+ *
+ * Skip an int3 exception when it occurs after a breakpoint has been
+ * removed. Backtrack eip by 1 since the int3 would have caused it to
+ * increment by 1.
+ */
+int kgdb_skipexception(int exception, struct pt_regs *regs)
+{
+ if (exception == 3 && kgdb_isremovedbreak(regs->ip - 1)) {
+ regs->ip -= 1;
+ return 1;
+ }
+ return 0;
+}
+
+unsigned long kgdb_arch_pc(int exception, struct pt_regs *regs)
+{
+ if (exception == 3)
+ return instruction_pointer(regs) - 1;
+ return instruction_pointer(regs);
+}
+
+struct kgdb_arch arch_kgdb_ops = {
+ /* Breakpoint instruction: */
+ .gdb_bpt_instr = { 0xcc },
+ .flags = KGDB_HW_BREAKPOINT,
+ .set_hw_breakpoint = kgdb_set_hw_break,
+ .remove_hw_breakpoint = kgdb_remove_hw_break,
+ .remove_all_hw_break = kgdb_remove_all_hw_break,
+ .correct_hw_break = kgdb_correct_hw_break,
+};
diff --git a/arch/x86/kernel/kgdb.c b/arch/x86/kernel/kgdb.c
deleted file mode 100644
index 88bfa45..0000000
--- a/arch/x86/kernel/kgdb.c
+++ /dev/null
@@ -1,567 +0,0 @@
-/*
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License as published by the
- * Free Software Foundation; either version 2, or (at your option) any
- * later version.
- *
- * 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.
- *
- */
-
-/*
- * Copyright (C) 2004 Amit S. Kale <amitkale@linsyssoft.com>
- * Copyright (C) 2000-2001 VERITAS Software Corporation.
- * Copyright (C) 2002 Andi Kleen, SuSE Labs
- * Copyright (C) 2004 LinSysSoft Technologies Pvt. Ltd.
- * Copyright (C) 2007 MontaVista Software, Inc.
- * Copyright (C) 2007-2008 Jason Wessel, Wind River Systems, Inc.
- */
-/****************************************************************************
- * Contributor: Lake Stevens Instrument Division$
- * Written by: Glenn Engel $
- * Updated by: Amit Kale<akale@veritas.com>
- * Updated by: Tom Rini <trini@kernel.crashing.org>
- * Updated by: Jason Wessel <jason.wessel@windriver.com>
- * Modified for 386 by Jim Kingdon, Cygnus Support.
- * Origianl kgdb, compatibility with 2.1.xx kernel by
- * David Grothe <dave@gcom.com>
- * Integrated into 2.2.5 kernel by Tigran Aivazian <tigran@sco.com>
- * X86_64 changes from Andi Kleen's patch merged by Jim Houston
- */
-#include <linux/spinlock.h>
-#include <linux/kdebug.h>
-#include <linux/string.h>
-#include <linux/kernel.h>
-#include <linux/ptrace.h>
-#include <linux/sched.h>
-#include <linux/delay.h>
-#include <linux/kgdb.h>
-#include <linux/init.h>
-#include <linux/smp.h>
-#include <linux/nmi.h>
-
-#include <asm/apicdef.h>
-#include <asm/system.h>
-
-#ifdef CONFIG_X86_32
-# include <mach_ipi.h>
-#else
-# include <asm/mach_apic.h>
-#endif
-
-/*
- * Put the error code here just in case the user cares:
- */
-static int gdb_x86errcode;
-
-/*
- * Likewise, the vector number here (since GDB only gets the signal
- * number through the usual means, and that's not very specific):
- */
-static int gdb_x86vector = -1;
-
-/**
- * pt_regs_to_gdb_regs - Convert ptrace regs to GDB regs
- * @gdb_regs: A pointer to hold the registers in the order GDB wants.
- * @regs: The &struct pt_regs of the current process.
- *
- * Convert the pt_regs in @regs into the format for registers that
- * GDB expects, stored in @gdb_regs.
- */
-void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs)
-{
- gdb_regs[GDB_AX] = regs->ax;
- gdb_regs[GDB_BX] = regs->bx;
- gdb_regs[GDB_CX] = regs->cx;
- gdb_regs[GDB_DX] = regs->dx;
- gdb_regs[GDB_SI] = regs->si;
- gdb_regs[GDB_DI] = regs->di;
- gdb_regs[GDB_BP] = regs->bp;
- gdb_regs[GDB_PS] = regs->flags;
- gdb_regs[GDB_PC] = regs->ip;
-#ifdef CONFIG_X86_32
- gdb_regs[GDB_DS] = regs->ds;
- gdb_regs[GDB_ES] = regs->es;
- gdb_regs[GDB_CS] = regs->cs;
- gdb_regs[GDB_SS] = __KERNEL_DS;
- gdb_regs[GDB_FS] = 0xFFFF;
- gdb_regs[GDB_GS] = 0xFFFF;
-#else
- gdb_regs[GDB_R8] = regs->r8;
- gdb_regs[GDB_R9] = regs->r9;
- gdb_regs[GDB_R10] = regs->r10;
- gdb_regs[GDB_R11] = regs->r11;
- gdb_regs[GDB_R12] = regs->r12;
- gdb_regs[GDB_R13] = regs->r13;
- gdb_regs[GDB_R14] = regs->r14;
- gdb_regs[GDB_R15] = regs->r15;
-#endif
- gdb_regs[GDB_SP] = regs->sp;
-}
-
-/**
- * sleeping_thread_to_gdb_regs - Convert ptrace regs to GDB regs
- * @gdb_regs: A pointer to hold the registers in the order GDB wants.
- * @p: The &struct task_struct of the desired process.
- *
- * Convert the register values of the sleeping process in @p to
- * the format that GDB expects.
- * This function is called when kgdb does not have access to the
- * &struct pt_regs and therefore it should fill the gdb registers
- * @gdb_regs with what has been saved in &struct thread_struct
- * thread field during switch_to.
- */
-void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p)
-{
- gdb_regs[GDB_AX] = 0;
- gdb_regs[GDB_BX] = 0;
- gdb_regs[GDB_CX] = 0;
- gdb_regs[GDB_DX] = 0;
- gdb_regs[GDB_SI] = 0;
- gdb_regs[GDB_DI] = 0;
- gdb_regs[GDB_BP] = *(unsigned long *)p->thread.sp;
-#ifdef CONFIG_X86_32
- gdb_regs[GDB_DS] = __KERNEL_DS;
- gdb_regs[GDB_ES] = __KERNEL_DS;
- gdb_regs[GDB_PS] = 0;
- gdb_regs[GDB_CS] = __KERNEL_CS;
- gdb_regs[GDB_PC] = p->thread.ip;
- gdb_regs[GDB_SS] = __KERNEL_DS;
- gdb_regs[GDB_FS] = 0xFFFF;
- gdb_regs[GDB_GS] = 0xFFFF;
-#else
- gdb_regs[GDB_PS] = *(unsigned long *)(p->thread.sp + 8);
- gdb_regs[GDB_PC] = 0;
- gdb_regs[GDB_R8] = 0;
- gdb_regs[GDB_R9] = 0;
- gdb_regs[GDB_R10] = 0;
- gdb_regs[GDB_R11] = 0;
- gdb_regs[GDB_R12] = 0;
- gdb_regs[GDB_R13] = 0;
- gdb_regs[GDB_R14] = 0;
- gdb_regs[GDB_R15] = 0;
-#endif
- gdb_regs[GDB_SP] = p->thread.sp;
-}
-
-/**
- * gdb_regs_to_pt_regs - Convert GDB regs to ptrace regs.
- * @gdb_regs: A pointer to hold the registers we've received from GDB.
- * @regs: A pointer to a &struct pt_regs to hold these values in.
- *
- * Convert the GDB regs in @gdb_regs into the pt_regs, and store them
- * in @regs.
- */
-void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs)
-{
- regs->ax = gdb_regs[GDB_AX];
- regs->bx = gdb_regs[GDB_BX];
- regs->cx = gdb_regs[GDB_CX];
- regs->dx = gdb_regs[GDB_DX];
- regs->si = gdb_regs[GDB_SI];
- regs->di = gdb_regs[GDB_DI];
- regs->bp = gdb_regs[GDB_BP];
- regs->flags = gdb_regs[GDB_PS];
- regs->ip = gdb_regs[GDB_PC];
-#ifdef CONFIG_X86_32
- regs->ds = gdb_regs[GDB_DS];
- regs->es = gdb_regs[GDB_ES];
- regs->cs = gdb_regs[GDB_CS];
-#else
- regs->r8 = gdb_regs[GDB_R8];
- regs->r9 = gdb_regs[GDB_R9];
- regs->r10 = gdb_regs[GDB_R10];
- regs->r11 = gdb_regs[GDB_R11];
- regs->r12 = gdb_regs[GDB_R12];
- regs->r13 = gdb_regs[GDB_R13];
- regs->r14 = gdb_regs[GDB_R14];
- regs->r15 = gdb_regs[GDB_R15];
-#endif
-}
-
-static struct hw_breakpoint {
- unsigned enabled;
- unsigned type;
- unsigned len;
- unsigned long addr;
-} breakinfo[4];
-
-static void kgdb_correct_hw_break(void)
-{
- unsigned long dr7;
- int correctit = 0;
- int breakbit;
- int breakno;
-
- get_debugreg(dr7, 7);
- for (breakno = 0; breakno < 4; breakno++) {
- breakbit = 2 << (breakno << 1);
- if (!(dr7 & breakbit) && breakinfo[breakno].enabled) {
- correctit = 1;
- dr7 |= breakbit;
- dr7 &= ~(0xf0000 << (breakno << 2));
- dr7 |= ((breakinfo[breakno].len << 2) |
- breakinfo[breakno].type) <<
- ((breakno << 2) + 16);
- if (breakno >= 0 && breakno <= 3)
- set_debugreg(breakinfo[breakno].addr, breakno);
-
- } else {
- if ((dr7 & breakbit) && !breakinfo[breakno].enabled) {
- correctit = 1;
- dr7 &= ~breakbit;
- dr7 &= ~(0xf0000 << (breakno << 2));
- }
- }
- }
- if (correctit)
- set_debugreg(dr7, 7);
-}
-
-static int
-kgdb_remove_hw_break(unsigned long addr, int len, enum kgdb_bptype bptype)
-{
- int i;
-
- for (i = 0; i < 4; i++)
- if (breakinfo[i].addr == addr && breakinfo[i].enabled)
- break;
- if (i == 4)
- return -1;
-
- breakinfo[i].enabled = 0;
-
- return 0;
-}
-
-static void kgdb_remove_all_hw_break(void)
-{
- int i;
-
- for (i = 0; i < 4; i++)
- memset(&breakinfo[i], 0, sizeof(struct hw_breakpoint));
-}
-
-static int
-kgdb_set_hw_break(unsigned long addr, int len, enum kgdb_bptype bptype)
-{
- unsigned type;
- int i;
-
- for (i = 0; i < 4; i++)
- if (!breakinfo[i].enabled)
- break;
- if (i == 4)
- return -1;
-
- switch (bptype) {
- case BP_HARDWARE_BREAKPOINT:
- type = 0;
- len = 1;
- break;
- case BP_WRITE_WATCHPOINT:
- type = 1;
- break;
- case BP_ACCESS_WATCHPOINT:
- type = 3;
- break;
- default:
- return -1;
- }
-
- if (len == 1 || len == 2 || len == 4)
- breakinfo[i].len = len - 1;
- else
- return -1;
-
- breakinfo[i].enabled = 1;
- breakinfo[i].addr = addr;
- breakinfo[i].type = type;
-
- return 0;
-}
-
-/**
- * kgdb_disable_hw_debug - Disable hardware debugging while we in kgdb.
- * @regs: Current &struct pt_regs.
- *
- * This function will be called if the particular architecture must
- * disable hardware debugging while it is processing gdb packets or
- * handling exception.
- */
-void kgdb_disable_hw_debug(struct pt_regs *regs)
-{
- /* Disable hardware debugging while we are in kgdb: */
- set_debugreg(0UL, 7);
-}
-
-/**
- * kgdb_post_primary_code - Save error vector/code numbers.
- * @regs: Original pt_regs.
- * @e_vector: Original error vector.
- * @err_code: Original error code.
- *
- * This is needed on architectures which support SMP and KGDB.
- * This function is called after all the slave cpus have been put
- * to a know spin state and the primary CPU has control over KGDB.
- */
-void kgdb_post_primary_code(struct pt_regs *regs, int e_vector, int err_code)
-{
- /* primary processor is completely in the debugger */
- gdb_x86vector = e_vector;
- gdb_x86errcode = err_code;
-}
-
-#ifdef CONFIG_SMP
-/**
- * kgdb_roundup_cpus - Get other CPUs into a holding pattern
- * @flags: Current IRQ state
- *
- * On SMP systems, we need to get the attention of the other CPUs
- * and get them be in a known state. This should do what is needed
- * to get the other CPUs to call kgdb_wait(). Note that on some arches,
- * the NMI approach is not used for rounding up all the CPUs. For example,
- * in case of MIPS, smp_call_function() is used to roundup CPUs. In
- * this case, we have to make sure that interrupts are enabled before
- * calling smp_call_function(). The argument to this function is
- * the flags that will be used when restoring the interrupts. There is
- * local_irq_save() call before kgdb_roundup_cpus().
- *
- * On non-SMP systems, this is not called.
- */
-void kgdb_roundup_cpus(unsigned long flags)
-{
- send_IPI_allbutself(APIC_DM_NMI);
-}
-#endif
-
-/**
- * kgdb_arch_handle_exception - Handle architecture specific GDB packets.
- * @vector: The error vector of the exception that happened.
- * @signo: The signal number of the exception that happened.
- * @err_code: The error code of the exception that happened.
- * @remcom_in_buffer: The buffer of the packet we have read.
- * @remcom_out_buffer: The buffer of %BUFMAX bytes to write a packet into.
- * @regs: The &struct pt_regs of the current process.
- *
- * This function MUST handle the 'c' and 's' command packets,
- * as well packets to set / remove a hardware breakpoint, if used.
- * If there are additional packets which the hardware needs to handle,
- * they are handled here. The code should return -1 if it wants to
- * process more packets, and a %0 or %1 if it wants to exit from the
- * kgdb callback.
- */
-int kgdb_arch_handle_exception(int e_vector, int signo, int err_code,
- char *remcomInBuffer, char *remcomOutBuffer,
- struct pt_regs *linux_regs)
-{
- unsigned long addr;
- unsigned long dr6;
- char *ptr;
- int newPC;
-
- switch (remcomInBuffer[0]) {
- case 'c':
- case 's':
- /* try to read optional parameter, pc unchanged if no parm */
- ptr = &remcomInBuffer[1];
- if (kgdb_hex2long(&ptr, &addr))
- linux_regs->ip = addr;
- newPC = linux_regs->ip;
-
- /* clear the trace bit */
- linux_regs->flags &= ~TF_MASK;
- atomic_set(&kgdb_cpu_doing_single_step, -1);
-
- /* set the trace bit if we're stepping */
- if (remcomInBuffer[0] == 's') {
- linux_regs->flags |= TF_MASK;
- kgdb_single_step = 1;
- if (kgdb_contthread) {
- atomic_set(&kgdb_cpu_doing_single_step,
- raw_smp_processor_id());
- }
- }
-
- get_debugreg(dr6, 6);
- if (!(dr6 & 0x4000)) {
- int breakno;
-
- for (breakno = 0; breakno < 4; breakno++) {
- if (dr6 & (1 << breakno) &&
- breakinfo[breakno].type == 0) {
- /* Set restore flag: */
- linux_regs->flags |= X86_EFLAGS_RF;
- break;
- }
- }
- }
- set_debugreg(0UL, 6);
- kgdb_correct_hw_break();
-
- return 0;
- }
-
- /* this means that we do not want to exit from the handler: */
- return -1;
-}
-
-static inline int
-single_step_cont(struct pt_regs *regs, struct die_args *args)
-{
- /*
- * Single step exception from kernel space to user space so
- * eat the exception and continue the process:
- */
- printk(KERN_ERR "KGDB: trap/step from kernel to user space, "
- "resuming...\n");
- kgdb_arch_handle_exception(args->trapnr, args->signr,
- args->err, "c", "", regs);
-
- return NOTIFY_STOP;
-}
-
-static int was_in_debug_nmi[NR_CPUS];
-
-static int __kgdb_notify(struct die_args *args, unsigned long cmd)
-{
- struct pt_regs *regs = args->regs;
-
- switch (cmd) {
- case DIE_NMI:
- if (atomic_read(&kgdb_active) != -1) {
- /* KGDB CPU roundup */
- kgdb_nmicallback(raw_smp_processor_id(), regs);
- was_in_debug_nmi[raw_smp_processor_id()] = 1;
- touch_nmi_watchdog();
- return NOTIFY_STOP;
- }
- return NOTIFY_DONE;
-
- case DIE_NMI_IPI:
- if (atomic_read(&kgdb_active) != -1) {
- /* KGDB CPU roundup */
- kgdb_nmicallback(raw_smp_processor_id(), regs);
- was_in_debug_nmi[raw_smp_processor_id()] = 1;
- touch_nmi_watchdog();
- }
- return NOTIFY_DONE;
-
- case DIE_NMIUNKNOWN:
- if (was_in_debug_nmi[raw_smp_processor_id()]) {
- was_in_debug_nmi[raw_smp_processor_id()] = 0;
- return NOTIFY_STOP;
- }
- return NOTIFY_DONE;
-
- case DIE_NMIWATCHDOG:
- if (atomic_read(&kgdb_active) != -1) {
- /* KGDB CPU roundup: */
- kgdb_nmicallback(raw_smp_processor_id(), regs);
- return NOTIFY_STOP;
- }
- /* Enter debugger: */
- break;
-
- case DIE_DEBUG:
- if (atomic_read(&kgdb_cpu_doing_single_step) ==
- raw_smp_processor_id() &&
- user_mode(regs))
- return single_step_cont(regs, args);
- /* fall through */
- default:
- if (user_mode(regs))
- return NOTIFY_DONE;
- }
-
- if (kgdb_handle_exception(args->trapnr, args->signr, args->err, 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,
-
- /*
- * Lowest-prio notifier priority, we want to be notified last:
- */
- .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)
-{
- return register_die_notifier(&kgdb_notifier);
-}
-
-/**
- * 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_die_notifier(&kgdb_notifier);
-}
-
-/**
- *
- * kgdb_skipexception - Bail of of KGDB when we've been triggered.
- * @exception: Exception vector number
- * @regs: Current &struct pt_regs.
- *
- * On some architectures we need to skip a breakpoint exception when
- * it occurs after a breakpoint has been removed.
- *
- * Skip an int3 exception when it occurs after a breakpoint has been
- * removed. Backtrack eip by 1 since the int3 would have caused it to
- * increment by 1.
- */
-int kgdb_skipexception(int exception, struct pt_regs *regs)
-{
- if (exception == 3 && kgdb_isremovedbreak(regs->ip - 1)) {
- regs->ip -= 1;
- return 1;
- }
- return 0;
-}
-
-unsigned long kgdb_arch_pc(int exception, struct pt_regs *regs)
-{
- if (exception == 3)
- return instruction_pointer(regs) - 1;
- return instruction_pointer(regs);
-}
-
-struct kgdb_arch arch_kgdb_ops = {
- /* Breakpoint instruction: */
- .gdb_bpt_instr = { 0xcc },
- .flags = KGDB_HW_BREAKPOINT,
- .set_hw_breakpoint = kgdb_set_hw_break,
- .remove_hw_breakpoint = kgdb_remove_hw_break,
- .remove_all_hw_break = kgdb_remove_all_hw_break,
- .correct_hw_break = kgdb_correct_hw_break,
-};
diff --git a/kernel/Makefile b/kernel/Makefile
index 05c8003..6c584c5 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -53,7 +53,6 @@ obj-$(CONFIG_AUDIT) += audit.o auditfilter.o
obj-$(CONFIG_AUDITSYSCALL) += auditsc.o
obj-$(CONFIG_AUDIT_TREE) += audit_tree.o
obj-$(CONFIG_KPROBES) += kprobes.o
-obj-$(CONFIG_KGDB) += kgdb.o
obj-$(CONFIG_DETECT_SOFTLOCKUP) += softlockup.o
obj-$(CONFIG_GENERIC_HARDIRQS) += irq/
obj-$(CONFIG_SECCOMP) += seccomp.o
diff --git a/kernel/kgdb.c b/kernel/kgdb.c
deleted file mode 100644
index a453764..0000000
--- a/kernel/kgdb.c
+++ /dev/null
@@ -1,1680 +0,0 @@
-/*
- * KGDB stub.
- *
- * Maintainer: Jason Wessel <jason.wessel@windriver.com>
- *
- * Copyright (C) 2000-2001 VERITAS Software Corporation.
- * Copyright (C) 2002-2004 Timesys Corporation
- * Copyright (C) 2003-2004 Amit S. Kale <amitkale@linsyssoft.com>
- * Copyright (C) 2004 Pavel Machek <pavel@suse.cz>
- * Copyright (C) 2004-2006 Tom Rini <trini@kernel.crashing.org>
- * Copyright (C) 2004-2006 LinSysSoft Technologies Pvt. Ltd.
- * Copyright (C) 2005-2008 Wind River Systems, Inc.
- * Copyright (C) 2007 MontaVista Software, Inc.
- * Copyright (C) 2008 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
- *
- * Contributors at various stages not listed above:
- * Jason Wessel ( jason.wessel@windriver.com )
- * George Anzinger <george@mvista.com>
- * Anurekh Saxena (anurekh.saxena@timesys.com)
- * Lake Stevens Instrument Division (Glenn Engel)
- * Jim Kingdon, Cygnus Support.
- *
- * Original KGDB stub: David Grothe <dave@gcom.com>,
- * Tigran Aivazian <tigran@sco.com>
- *
- * This file is licensed under the terms of the GNU General Public License
- * version 2. This program is licensed "as is" without any warranty of any
- * kind, whether express or implied.
- */
-#include <linux/pid_namespace.h>
-#include <linux/clocksource.h>
-#include <linux/interrupt.h>
-#include <linux/spinlock.h>
-#include <linux/console.h>
-#include <linux/threads.h>
-#include <linux/uaccess.h>
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/ptrace.h>
-#include <linux/reboot.h>
-#include <linux/string.h>
-#include <linux/delay.h>
-#include <linux/sched.h>
-#include <linux/sysrq.h>
-#include <linux/init.h>
-#include <linux/kgdb.h>
-#include <linux/pid.h>
-#include <linux/smp.h>
-#include <linux/mm.h>
-
-#include <asm/cacheflush.h>
-#include <asm/byteorder.h>
-#include <asm/atomic.h>
-#include <asm/system.h>
-
-static int kgdb_break_asap;
-
-struct kgdb_state {
- int ex_vector;
- int signo;
- int err_code;
- int cpu;
- int pass_exception;
- long threadid;
- long kgdb_usethreadid;
- struct pt_regs *linux_regs;
-};
-
-static struct debuggerinfo_struct {
- void *debuggerinfo;
- struct task_struct *task;
-} kgdb_info[NR_CPUS];
-
-/**
- * kgdb_connected - Is a host GDB connected to us?
- */
-int kgdb_connected;
-EXPORT_SYMBOL_GPL(kgdb_connected);
-
-/* All the KGDB handlers are installed */
-static int kgdb_io_module_registered;
-
-/* Guard for recursive entry */
-static int exception_level;
-
-static struct kgdb_io *kgdb_io_ops;
-static DEFINE_SPINLOCK(kgdb_registration_lock);
-
-/* kgdb console driver is loaded */
-static int kgdb_con_registered;
-/* determine if kgdb console output should be used */
-static int kgdb_use_con;
-
-static int __init opt_kgdb_con(char *str)
-{
- kgdb_use_con = 1;
- return 0;
-}
-
-early_param("kgdbcon", opt_kgdb_con);
-
-module_param(kgdb_use_con, int, 0644);
-
-/*
- * Holds information about breakpoints in a kernel. These breakpoints are
- * added and removed by gdb.
- */
-static struct kgdb_bkpt kgdb_break[KGDB_MAX_BREAKPOINTS] = {
- [0 ... KGDB_MAX_BREAKPOINTS-1] = { .state = BP_UNDEFINED }
-};
-
-/*
- * The CPU# of the active CPU, or -1 if none:
- */
-atomic_t kgdb_active = ATOMIC_INIT(-1);
-
-/*
- * We use NR_CPUs not PERCPU, in case kgdb is used to debug early
- * bootup code (which might not have percpu set up yet):
- */
-static atomic_t passive_cpu_wait[NR_CPUS];
-static atomic_t cpu_in_kgdb[NR_CPUS];
-atomic_t kgdb_setting_breakpoint;
-
-struct task_struct *kgdb_usethread;
-struct task_struct *kgdb_contthread;
-
-int kgdb_single_step;
-
-/* Our I/O buffers. */
-static char remcom_in_buffer[BUFMAX];
-static char remcom_out_buffer[BUFMAX];
-
-/* Storage for the registers, in GDB format. */
-static unsigned long gdb_regs[(NUMREGBYTES +
- sizeof(unsigned long) - 1) /
- sizeof(unsigned long)];
-
-/* to keep track of the CPU which is doing the single stepping*/
-atomic_t kgdb_cpu_doing_single_step = ATOMIC_INIT(-1);
-
-/*
- * Finally, some KGDB code :-)
- */
-
-/*
- * Weak aliases for breakpoint management,
- * can be overriden by architectures when needed:
- */
-int __weak kgdb_validate_break_address(unsigned long addr)
-{
- char tmp_variable[BREAK_INSTR_SIZE];
-
- return probe_kernel_read(tmp_variable, (char *)addr, BREAK_INSTR_SIZE);
-}
-
-int __weak kgdb_arch_set_breakpoint(unsigned long addr, char *saved_instr)
-{
- int err;
-
- err = probe_kernel_read(saved_instr, (char *)addr, BREAK_INSTR_SIZE);
- if (err)
- return err;
-
- return probe_kernel_write((char *)addr, arch_kgdb_ops.gdb_bpt_instr,
- BREAK_INSTR_SIZE);
-}
-
-int __weak kgdb_arch_remove_breakpoint(unsigned long addr, char *bundle)
-{
- return probe_kernel_write((char *)addr,
- (char *)bundle, BREAK_INSTR_SIZE);
-}
-
-unsigned long __weak kgdb_arch_pc(int exception, struct pt_regs *regs)
-{
- return instruction_pointer(regs);
-}
-
-int __weak kgdb_arch_init(void)
-{
- return 0;
-}
-
-/**
- * kgdb_disable_hw_debug - Disable hardware debugging while we in kgdb.
- * @regs: Current &struct pt_regs.
- *
- * This function will be called if the particular architecture must
- * disable hardware debugging while it is processing gdb packets or
- * handling exception.
- */
-void __weak kgdb_disable_hw_debug(struct pt_regs *regs)
-{
-}
-
-/*
- * GDB remote protocol parser:
- */
-
-static const char hexchars[] = "0123456789abcdef";
-
-static int hex(char ch)
-{
- if ((ch >= 'a') && (ch <= 'f'))
- return ch - 'a' + 10;
- if ((ch >= '0') && (ch <= '9'))
- return ch - '0';
- if ((ch >= 'A') && (ch <= 'F'))
- return ch - 'A' + 10;
- return -1;
-}
-
-/* scan for the sequence $<data>#<checksum> */
-static void get_packet(char *buffer)
-{
- unsigned char checksum;
- unsigned char xmitcsum;
- int count;
- char ch;
-
- do {
- /*
- * Spin and wait around for the start character, ignore all
- * other characters:
- */
- while ((ch = (kgdb_io_ops->read_char())) != '$')
- /* nothing */;
-
- kgdb_connected = 1;
- checksum = 0;
- xmitcsum = -1;
-
- count = 0;
-
- /*
- * now, read until a # or end of buffer is found:
- */
- while (count < (BUFMAX - 1)) {
- ch = kgdb_io_ops->read_char();
- if (ch == '#')
- break;
- checksum = checksum + ch;
- buffer[count] = ch;
- count = count + 1;
- }
- buffer[count] = 0;
-
- if (ch == '#') {
- xmitcsum = hex(kgdb_io_ops->read_char()) << 4;
- xmitcsum += hex(kgdb_io_ops->read_char());
-
- if (checksum != xmitcsum)
- /* failed checksum */
- kgdb_io_ops->write_char('-');
- else
- /* successful transfer */
- kgdb_io_ops->write_char('+');
- if (kgdb_io_ops->flush)
- kgdb_io_ops->flush();
- }
- } while (checksum != xmitcsum);
-}
-
-/*
- * Send the packet in buffer.
- * Check for gdb connection if asked for.
- */
-static void put_packet(char *buffer)
-{
- unsigned char checksum;
- int count;
- char ch;
-
- /*
- * $<packet info>#<checksum>.
- */
- while (1) {
- kgdb_io_ops->write_char('$');
- checksum = 0;
- count = 0;
-
- while ((ch = buffer[count])) {
- kgdb_io_ops->write_char(ch);
- checksum += ch;
- count++;
- }
-
- kgdb_io_ops->write_char('#');
- kgdb_io_ops->write_char(hexchars[checksum >> 4]);
- kgdb_io_ops->write_char(hexchars[checksum & 0xf]);
- if (kgdb_io_ops->flush)
- kgdb_io_ops->flush();
-
- /* Now see what we get in reply. */
- ch = kgdb_io_ops->read_char();
-
- if (ch == 3)
- ch = kgdb_io_ops->read_char();
-
- /* If we get an ACK, we are done. */
- if (ch == '+')
- return;
-
- /*
- * If we get the start of another packet, this means
- * that GDB is attempting to reconnect. We will NAK
- * the packet being sent, and stop trying to send this
- * packet.
- */
- if (ch == '$') {
- kgdb_io_ops->write_char('-');
- if (kgdb_io_ops->flush)
- kgdb_io_ops->flush();
- return;
- }
- }
-}
-
-static char *pack_hex_byte(char *pkt, u8 byte)
-{
- *pkt++ = hexchars[byte >> 4];
- *pkt++ = hexchars[byte & 0xf];
-
- return pkt;
-}
-
-/*
- * Convert the memory pointed to by mem into hex, placing result in buf.
- * Return a pointer to the last char put in buf (null). May return an error.
- */
-int kgdb_mem2hex(char *mem, char *buf, int count)
-{
- char *tmp;
- int err;
-
- /*
- * We use the upper half of buf as an intermediate buffer for the
- * raw memory copy. Hex conversion will work against this one.
- */
- tmp = buf + count;
-
- err = probe_kernel_read(tmp, mem, count);
- if (!err) {
- while (count > 0) {
- buf = pack_hex_byte(buf, *tmp);
- tmp++;
- count--;
- }
-
- *buf = 0;
- }
-
- return err;
-}
-
-/*
- * Copy the binary array pointed to by buf into mem. Fix $, #, and
- * 0x7d escaped with 0x7d. Return a pointer to the character after
- * the last byte written.
- */
-static int kgdb_ebin2mem(char *buf, char *mem, int count)
-{
- int err = 0;
- char c;
-
- while (count-- > 0) {
- c = *buf++;
- if (c == 0x7d)
- c = *buf++ ^ 0x20;
-
- err = probe_kernel_write(mem, &c, 1);
- if (err)
- break;
-
- mem++;
- }
-
- return err;
-}
-
-/*
- * Convert the hex array pointed to by buf into binary to be placed in mem.
- * Return a pointer to the character AFTER the last byte written.
- * May return an error.
- */
-int kgdb_hex2mem(char *buf, char *mem, int count)
-{
- char *tmp_raw;
- char *tmp_hex;
-
- /*
- * We use the upper half of buf as an intermediate buffer for the
- * raw memory that is converted from hex.
- */
- tmp_raw = buf + count * 2;
-
- tmp_hex = tmp_raw - 1;
- while (tmp_hex >= buf) {
- tmp_raw--;
- *tmp_raw = hex(*tmp_hex--);
- *tmp_raw |= hex(*tmp_hex--) << 4;
- }
-
- return probe_kernel_write(mem, tmp_raw, count);
-}
-
-/*
- * While we find nice hex chars, build a long_val.
- * Return number of chars processed.
- */
-int kgdb_hex2long(char **ptr, long *long_val)
-{
- int hex_val;
- int num = 0;
-
- *long_val = 0;
-
- while (**ptr) {
- hex_val = hex(**ptr);
- if (hex_val < 0)
- break;
-
- *long_val = (*long_val << 4) | hex_val;
- num++;
- (*ptr)++;
- }
-
- return num;
-}
-
-/* Write memory due to an 'M' or 'X' packet. */
-static int write_mem_msg(int binary)
-{
- char *ptr = &remcom_in_buffer[1];
- unsigned long addr;
- unsigned long length;
- int err;
-
- if (kgdb_hex2long(&ptr, &addr) > 0 && *(ptr++) == ',' &&
- kgdb_hex2long(&ptr, &length) > 0 && *(ptr++) == ':') {
- if (binary)
- err = kgdb_ebin2mem(ptr, (char *)addr, length);
- else
- err = kgdb_hex2mem(ptr, (char *)addr, length);
- if (err)
- return err;
- if (CACHE_FLUSH_IS_SAFE)
- flush_icache_range(addr, addr + length + 1);
- return 0;
- }
-
- return -EINVAL;
-}
-
-static void error_packet(char *pkt, int error)
-{
- error = -error;
- pkt[0] = 'E';
- pkt[1] = hexchars[(error / 10)];
- pkt[2] = hexchars[(error % 10)];
- pkt[3] = '\0';
-}
-
-/*
- * Thread ID accessors. We represent a flat TID space to GDB, where
- * the per CPU idle threads (which under Linux all have PID 0) are
- * remapped to negative TIDs.
- */
-
-#define BUF_THREAD_ID_SIZE 16
-
-static char *pack_threadid(char *pkt, unsigned char *id)
-{
- char *limit;
-
- limit = pkt + BUF_THREAD_ID_SIZE;
- while (pkt < limit)
- pkt = pack_hex_byte(pkt, *id++);
-
- return pkt;
-}
-
-static void int_to_threadref(unsigned char *id, int value)
-{
- unsigned char *scan;
- int i = 4;
-
- scan = (unsigned char *)id;
- while (i--)
- *scan++ = 0;
- *scan++ = (value >> 24) & 0xff;
- *scan++ = (value >> 16) & 0xff;
- *scan++ = (value >> 8) & 0xff;
- *scan++ = (value & 0xff);
-}
-
-static struct task_struct *getthread(struct pt_regs *regs, int tid)
-{
- /*
- * Non-positive TIDs are remapped idle tasks:
- */
- if (tid <= 0)
- return idle_task(-tid);
-
- /*
- * find_task_by_pid() does not take the tasklist lock anymore
- * but is nicely RCU locked - hence is a pretty resilient
- * thing to use:
- */
- return find_task_by_pid(tid);
-}
-
-/*
- * CPU debug state control:
- */
-
-#ifdef CONFIG_SMP
-static void kgdb_wait(struct pt_regs *regs)
-{
- unsigned long flags;
- int cpu;
-
- local_irq_save(flags);
- cpu = raw_smp_processor_id();
- kgdb_info[cpu].debuggerinfo = regs;
- kgdb_info[cpu].task = current;
- /*
- * Make sure the above info reaches the primary CPU before
- * our cpu_in_kgdb[] flag setting does:
- */
- smp_wmb();
- atomic_set(&cpu_in_kgdb[cpu], 1);
-
- /*
- * The primary CPU must be active to enter here, but this is
- * guard in case the primary CPU had not been selected if
- * this was an entry via nmi.
- */
- while (atomic_read(&kgdb_active) == -1)
- cpu_relax();
-
- /* Wait till primary CPU goes completely into the debugger. */
- while (!atomic_read(&cpu_in_kgdb[atomic_read(&kgdb_active)]))
- cpu_relax();
-
- /* Wait till primary CPU is done with debugging */
- while (atomic_read(&passive_cpu_wait[cpu]))
- cpu_relax();
-
- kgdb_info[cpu].debuggerinfo = NULL;
- kgdb_info[cpu].task = NULL;
-
- /* fix up hardware debug registers on local cpu */
- if (arch_kgdb_ops.correct_hw_break)
- arch_kgdb_ops.correct_hw_break();
-
- /* Signal the primary CPU that we are done: */
- atomic_set(&cpu_in_kgdb[cpu], 0);
- clocksource_touch_watchdog();
- local_irq_restore(flags);
-}
-#endif
-
-/*
- * Some architectures need cache flushes when we set/clear a
- * breakpoint:
- */
-static void kgdb_flush_swbreak_addr(unsigned long addr)
-{
- if (!CACHE_FLUSH_IS_SAFE)
- return;
-
- if (current->mm) {
- flush_cache_range(current->mm->mmap_cache,
- addr, addr + BREAK_INSTR_SIZE);
- } else {
- flush_icache_range(addr, addr + BREAK_INSTR_SIZE);
- }
-}
-
-/*
- * SW breakpoint management:
- */
-static int kgdb_activate_sw_breakpoints(void)
-{
- unsigned long addr;
- int error = 0;
- int i;
-
- for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) {
- if (kgdb_break[i].state != BP_SET)
- continue;
-
- addr = kgdb_break[i].bpt_addr;
- error = kgdb_arch_set_breakpoint(addr,
- kgdb_break[i].saved_instr);
- if (error)
- return error;
-
- kgdb_flush_swbreak_addr(addr);
- kgdb_break[i].state = BP_ACTIVE;
- }
- return 0;
-}
-
-static int kgdb_set_sw_break(unsigned long addr)
-{
- int err = kgdb_validate_break_address(addr);
- int breakno = -1;
- int i;
-
- if (err)
- return err;
-
- for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) {
- if ((kgdb_break[i].state == BP_SET) &&
- (kgdb_break[i].bpt_addr == addr))
- return -EEXIST;
- }
- for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) {
- if (kgdb_break[i].state == BP_REMOVED &&
- kgdb_break[i].bpt_addr == addr) {
- breakno = i;
- break;
- }
- }
-
- if (breakno == -1) {
- for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) {
- if (kgdb_break[i].state == BP_UNDEFINED) {
- breakno = i;
- break;
- }
- }
- }
-
- if (breakno == -1)
- return -E2BIG;
-
- kgdb_break[breakno].state = BP_SET;
- kgdb_break[breakno].type = BP_BREAKPOINT;
- kgdb_break[breakno].bpt_addr = addr;
-
- return 0;
-}
-
-static int kgdb_deactivate_sw_breakpoints(void)
-{
- unsigned long addr;
- int error = 0;
- int i;
-
- for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) {
- if (kgdb_break[i].state != BP_ACTIVE)
- continue;
- addr = kgdb_break[i].bpt_addr;
- error = kgdb_arch_remove_breakpoint(addr,
- kgdb_break[i].saved_instr);
- if (error)
- return error;
-
- kgdb_flush_swbreak_addr(addr);
- kgdb_break[i].state = BP_SET;
- }
- return 0;
-}
-
-static int kgdb_remove_sw_break(unsigned long addr)
-{
- int i;
-
- for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) {
- if ((kgdb_break[i].state == BP_SET) &&
- (kgdb_break[i].bpt_addr == addr)) {
- kgdb_break[i].state = BP_REMOVED;
- return 0;
- }
- }
- return -ENOENT;
-}
-
-int kgdb_isremovedbreak(unsigned long addr)
-{
- int i;
-
- for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) {
- if ((kgdb_break[i].state == BP_REMOVED) &&
- (kgdb_break[i].bpt_addr == addr))
- return 1;
- }
- return 0;
-}
-
-int remove_all_break(void)
-{
- unsigned long addr;
- int error;
- int i;
-
- /* Clear memory breakpoints. */
- for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) {
- if (kgdb_break[i].state != BP_SET)
- continue;
- addr = kgdb_break[i].bpt_addr;
- error = kgdb_arch_remove_breakpoint(addr,
- kgdb_break[i].saved_instr);
- if (error)
- return error;
- kgdb_break[i].state = BP_REMOVED;
- }
-
- /* Clear hardware breakpoints. */
- if (arch_kgdb_ops.remove_all_hw_break)
- arch_kgdb_ops.remove_all_hw_break();
-
- return 0;
-}
-
-/*
- * Remap normal tasks to their real PID, idle tasks to -1 ... -NR_CPUs:
- */
-static inline int shadow_pid(int realpid)
-{
- if (realpid)
- return realpid;
-
- return -1-raw_smp_processor_id();
-}
-
-static char gdbmsgbuf[BUFMAX + 1];
-
-static void kgdb_msg_write(const char *s, int len)
-{
- char *bufptr;
- int wcount;
- int i;
-
- /* 'O'utput */
- gdbmsgbuf[0] = 'O';
-
- /* Fill and send buffers... */
- while (len > 0) {
- bufptr = gdbmsgbuf + 1;
-
- /* Calculate how many this time */
- if ((len << 1) > (BUFMAX - 2))
- wcount = (BUFMAX - 2) >> 1;
- else
- wcount = len;
-
- /* Pack in hex chars */
- for (i = 0; i < wcount; i++)
- bufptr = pack_hex_byte(bufptr, s[i]);
- *bufptr = '\0';
-
- /* Move up */
- s += wcount;
- len -= wcount;
-
- /* Write packet */
- put_packet(gdbmsgbuf);
- }
-}
-
-/*
- * Return true if there is a valid kgdb I/O module. Also if no
- * debugger is attached a message can be printed to the console about
- * waiting for the debugger to attach.
- *
- * The print_wait argument is only to be true when called from inside
- * the core kgdb_handle_exception, because it will wait for the
- * debugger to attach.
- */
-static int kgdb_io_ready(int print_wait)
-{
- if (!kgdb_io_ops)
- return 0;
- if (kgdb_connected)
- return 1;
- if (atomic_read(&kgdb_setting_breakpoint))
- return 1;
- if (print_wait)
- printk(KERN_CRIT "KGDB: Waiting for remote debugger\n");
- return 1;
-}
-
-/*
- * All the functions that start with gdb_cmd are the various
- * operations to implement the handlers for the gdbserial protocol
- * where KGDB is communicating with an external debugger
- */
-
-/* Handle the '?' status packets */
-static void gdb_cmd_status(struct kgdb_state *ks)
-{
- /*
- * We know that this packet is only sent
- * during initial connect. So to be safe,
- * we clear out our breakpoints now in case
- * GDB is reconnecting.
- */
- remove_all_break();
-
- remcom_out_buffer[0] = 'S';
- pack_hex_byte(&remcom_out_buffer[1], ks->signo);
-}
-
-/* Handle the 'g' get registers request */
-static void gdb_cmd_getregs(struct kgdb_state *ks)
-{
- struct task_struct *thread;
- void *local_debuggerinfo;
- int i;
-
- thread = kgdb_usethread;
- if (!thread) {
- thread = kgdb_info[ks->cpu].task;
- local_debuggerinfo = kgdb_info[ks->cpu].debuggerinfo;
- } else {
- local_debuggerinfo = NULL;
- for (i = 0; i < NR_CPUS; i++) {
- /*
- * Try to find the task on some other
- * or possibly this node if we do not
- * find the matching task then we try
- * to approximate the results.
- */
- if (thread == kgdb_info[i].task)
- local_debuggerinfo = kgdb_info[i].debuggerinfo;
- }
- }
-
- /*
- * All threads that don't have debuggerinfo should be
- * in __schedule() sleeping, since all other CPUs
- * are in kgdb_wait, and thus have debuggerinfo.
- */
- if (local_debuggerinfo) {
- pt_regs_to_gdb_regs(gdb_regs, local_debuggerinfo);
- } else {
- /*
- * Pull stuff saved during switch_to; nothing
- * else is accessible (or even particularly
- * relevant).
- *
- * This should be enough for a stack trace.
- */
- sleeping_thread_to_gdb_regs(gdb_regs, thread);
- }
- kgdb_mem2hex((char *)gdb_regs, remcom_out_buffer, NUMREGBYTES);
-}
-
-/* Handle the 'G' set registers request */
-static void gdb_cmd_setregs(struct kgdb_state *ks)
-{
- kgdb_hex2mem(&remcom_in_buffer[1], (char *)gdb_regs, NUMREGBYTES);
-
- if (kgdb_usethread && kgdb_usethread != current) {
- error_packet(remcom_out_buffer, -EINVAL);
- } else {
- gdb_regs_to_pt_regs(gdb_regs, ks->linux_regs);
- strcpy(remcom_out_buffer, "OK");
- }
-}
-
-/* Handle the 'm' memory read bytes */
-static void gdb_cmd_memread(struct kgdb_state *ks)
-{
- char *ptr = &remcom_in_buffer[1];
- unsigned long length;
- unsigned long addr;
- int err;
-
- if (kgdb_hex2long(&ptr, &addr) > 0 && *ptr++ == ',' &&
- kgdb_hex2long(&ptr, &length) > 0) {
- err = kgdb_mem2hex((char *)addr, remcom_out_buffer, length);
- if (err)
- error_packet(remcom_out_buffer, err);
- } else {
- error_packet(remcom_out_buffer, -EINVAL);
- }
-}
-
-/* Handle the 'M' memory write bytes */
-static void gdb_cmd_memwrite(struct kgdb_state *ks)
-{
- int err = write_mem_msg(0);
-
- if (err)
- error_packet(remcom_out_buffer, err);
- else
- strcpy(remcom_out_buffer, "OK");
-}
-
-/* Handle the 'X' memory binary write bytes */
-static void gdb_cmd_binwrite(struct kgdb_state *ks)
-{
- int err = write_mem_msg(1);
-
- if (err)
- error_packet(remcom_out_buffer, err);
- else
- strcpy(remcom_out_buffer, "OK");
-}
-
-/* Handle the 'D' or 'k', detach or kill packets */
-static void gdb_cmd_detachkill(struct kgdb_state *ks)
-{
- int error;
-
- /* The detach case */
- if (remcom_in_buffer[0] == 'D') {
- error = remove_all_break();
- if (error < 0) {
- error_packet(remcom_out_buffer, error);
- } else {
- strcpy(remcom_out_buffer, "OK");
- kgdb_connected = 0;
- }
- put_packet(remcom_out_buffer);
- } else {
- /*
- * Assume the kill case, with no exit code checking,
- * trying to force detach the debugger:
- */
- remove_all_break();
- kgdb_connected = 0;
- }
-}
-
-/* Handle the 'R' reboot packets */
-static int gdb_cmd_reboot(struct kgdb_state *ks)
-{
- /* For now, only honor R0 */
- if (strcmp(remcom_in_buffer, "R0") == 0) {
- printk(KERN_CRIT "Executing emergency reboot\n");
- strcpy(remcom_out_buffer, "OK");
- put_packet(remcom_out_buffer);
-
- /*
- * Execution should not return from
- * machine_emergency_restart()
- */
- machine_emergency_restart();
- kgdb_connected = 0;
-
- return 1;
- }
- return 0;
-}
-
-/* Handle the 'q' query packets */
-static void gdb_cmd_query(struct kgdb_state *ks)
-{
- struct task_struct *thread;
- unsigned char thref[8];
- char *ptr;
- int i;
-
- switch (remcom_in_buffer[1]) {
- case 's':
- case 'f':
- if (memcmp(remcom_in_buffer + 2, "ThreadInfo", 10)) {
- error_packet(remcom_out_buffer, -EINVAL);
- break;
- }
-
- if (remcom_in_buffer[1] == 'f')
- ks->threadid = 1;
-
- remcom_out_buffer[0] = 'm';
- ptr = remcom_out_buffer + 1;
-
- for (i = 0; i < 17; ks->threadid++) {
- thread = getthread(ks->linux_regs, ks->threadid);
- if (thread) {
- int_to_threadref(thref, ks->threadid);
- pack_threadid(ptr, thref);
- ptr += BUF_THREAD_ID_SIZE;
- *(ptr++) = ',';
- i++;
- }
- }
- *(--ptr) = '\0';
- break;
-
- case 'C':
- /* Current thread id */
- strcpy(remcom_out_buffer, "QC");
- ks->threadid = shadow_pid(current->pid);
- int_to_threadref(thref, ks->threadid);
- pack_threadid(remcom_out_buffer + 2, thref);
- break;
- case 'T':
- if (memcmp(remcom_in_buffer + 1, "ThreadExtraInfo,", 16)) {
- error_packet(remcom_out_buffer, -EINVAL);
- break;
- }
- ks->threadid = 0;
- ptr = remcom_in_buffer + 17;
- kgdb_hex2long(&ptr, &ks->threadid);
- if (!getthread(ks->linux_regs, ks->threadid)) {
- error_packet(remcom_out_buffer, -EINVAL);
- break;
- }
- if (ks->threadid > 0) {
- kgdb_mem2hex(getthread(ks->linux_regs,
- ks->threadid)->comm,
- remcom_out_buffer, 16);
- } else {
- static char tmpstr[23 + BUF_THREAD_ID_SIZE];
-
- sprintf(tmpstr, "Shadow task %d for pid 0",
- (int)(-ks->threadid-1));
- kgdb_mem2hex(tmpstr, remcom_out_buffer, strlen(tmpstr));
- }
- break;
- }
-}
-
-/* Handle the 'H' task query packets */
-static void gdb_cmd_task(struct kgdb_state *ks)
-{
- struct task_struct *thread;
- char *ptr;
-
- switch (remcom_in_buffer[1]) {
- case 'g':
- ptr = &remcom_in_buffer[2];
- kgdb_hex2long(&ptr, &ks->threadid);
- thread = getthread(ks->linux_regs, ks->threadid);
- if (!thread && ks->threadid > 0) {
- error_packet(remcom_out_buffer, -EINVAL);
- break;
- }
- kgdb_usethread = thread;
- ks->kgdb_usethreadid = ks->threadid;
- strcpy(remcom_out_buffer, "OK");
- break;
- case 'c':
- ptr = &remcom_in_buffer[2];
- kgdb_hex2long(&ptr, &ks->threadid);
- if (!ks->threadid) {
- kgdb_contthread = NULL;
- } else {
- thread = getthread(ks->linux_regs, ks->threadid);
- if (!thread && ks->threadid > 0) {
- error_packet(remcom_out_buffer, -EINVAL);
- break;
- }
- kgdb_contthread = thread;
- }
- strcpy(remcom_out_buffer, "OK");
- break;
- }
-}
-
-/* Handle the 'T' thread query packets */
-static void gdb_cmd_thread(struct kgdb_state *ks)
-{
- char *ptr = &remcom_in_buffer[1];
- struct task_struct *thread;
-
- kgdb_hex2long(&ptr, &ks->threadid);
- thread = getthread(ks->linux_regs, ks->threadid);
- if (thread)
- strcpy(remcom_out_buffer, "OK");
- else
- error_packet(remcom_out_buffer, -EINVAL);
-}
-
-/* Handle the 'z' or 'Z' breakpoint remove or set packets */
-static void gdb_cmd_break(struct kgdb_state *ks)
-{
- /*
- * Since GDB-5.3, it's been drafted that '0' is a software
- * breakpoint, '1' is a hardware breakpoint, so let's do that.
- */
- char *bpt_type = &remcom_in_buffer[1];
- char *ptr = &remcom_in_buffer[2];
- unsigned long addr;
- unsigned long length;
- int error = 0;
-
- if (arch_kgdb_ops.set_hw_breakpoint && *bpt_type >= '1') {
- /* Unsupported */
- if (*bpt_type > '4')
- return;
- } else {
- if (*bpt_type != '0' && *bpt_type != '1')
- /* Unsupported. */
- return;
- }
-
- /*
- * Test if this is a hardware breakpoint, and
- * if we support it:
- */
- if (*bpt_type == '1' && !(arch_kgdb_ops.flags & KGDB_HW_BREAKPOINT))
- /* Unsupported. */
- return;
-
- if (*(ptr++) != ',') {
- error_packet(remcom_out_buffer, -EINVAL);
- return;
- }
- if (!kgdb_hex2long(&ptr, &addr)) {
- error_packet(remcom_out_buffer, -EINVAL);
- return;
- }
- if (*(ptr++) != ',' ||
- !kgdb_hex2long(&ptr, &length)) {
- error_packet(remcom_out_buffer, -EINVAL);
- return;
- }
-
- if (remcom_in_buffer[0] == 'Z' && *bpt_type == '0')
- error = kgdb_set_sw_break(addr);
- else if (remcom_in_buffer[0] == 'z' && *bpt_type == '0')
- error = kgdb_remove_sw_break(addr);
- else if (remcom_in_buffer[0] == 'Z')
- error = arch_kgdb_ops.set_hw_breakpoint(addr,
- (int)length, *bpt_type - '0');
- else if (remcom_in_buffer[0] == 'z')
- error = arch_kgdb_ops.remove_hw_breakpoint(addr,
- (int) length, *bpt_type - '0');
-
- if (error == 0)
- strcpy(remcom_out_buffer, "OK");
- else
- error_packet(remcom_out_buffer, error);
-}
-
-/* Handle the 'C' signal / exception passing packets */
-static int gdb_cmd_exception_pass(struct kgdb_state *ks)
-{
- /* C09 == pass exception
- * C15 == detach kgdb, pass exception
- */
- if (remcom_in_buffer[1] == '0' && remcom_in_buffer[2] == '9') {
-
- ks->pass_exception = 1;
- remcom_in_buffer[0] = 'c';
-
- } else if (remcom_in_buffer[1] == '1' && remcom_in_buffer[2] == '5') {
-
- ks->pass_exception = 1;
- remcom_in_buffer[0] = 'D';
- remove_all_break();
- kgdb_connected = 0;
- return 1;
-
- } else {
- error_packet(remcom_out_buffer, -EINVAL);
- return 0;
- }
-
- /* Indicate fall through */
- return -1;
-}
-
-/*
- * This function performs all gdbserial command procesing
- */
-static int gdb_serial_stub(struct kgdb_state *ks)
-{
- int error = 0;
- int tmp;
-
- /* Clear the out buffer. */
- memset(remcom_out_buffer, 0, sizeof(remcom_out_buffer));
-
- if (kgdb_connected) {
- unsigned char thref[8];
- char *ptr;
-
- /* Reply to host that an exception has occurred */
- ptr = remcom_out_buffer;
- *ptr++ = 'T';
- ptr = pack_hex_byte(ptr, ks->signo);
- ptr += strlen(strcpy(ptr, "thread:"));
- int_to_threadref(thref, shadow_pid(current->pid));
- ptr = pack_threadid(ptr, thref);
- *ptr++ = ';';
- put_packet(remcom_out_buffer);
- }
-
- kgdb_usethread = kgdb_info[ks->cpu].task;
- ks->kgdb_usethreadid = shadow_pid(kgdb_info[ks->cpu].task->pid);
- ks->pass_exception = 0;
-
- while (1) {
- error = 0;
-
- /* Clear the out buffer. */
- memset(remcom_out_buffer, 0, sizeof(remcom_out_buffer));
-
- get_packet(remcom_in_buffer);
-
- switch (remcom_in_buffer[0]) {
- case '?': /* gdbserial status */
- gdb_cmd_status(ks);
- break;
- case 'g': /* return the value of the CPU registers */
- gdb_cmd_getregs(ks);
- break;
- case 'G': /* set the value of the CPU registers - return OK */
- gdb_cmd_setregs(ks);
- break;
- case 'm': /* mAA..AA,LLLL Read LLLL bytes at address AA..AA */
- gdb_cmd_memread(ks);
- break;
- case 'M': /* MAA..AA,LLLL: Write LLLL bytes at address AA..AA */
- gdb_cmd_memwrite(ks);
- break;
- case 'X': /* XAA..AA,LLLL: Write LLLL bytes at address AA..AA */
- gdb_cmd_binwrite(ks);
- break;
- /* kill or detach. KGDB should treat this like a
- * continue.
- */
- case 'D': /* Debugger detach */
- case 'k': /* Debugger detach via kill */
- gdb_cmd_detachkill(ks);
- goto default_handle;
- case 'R': /* Reboot */
- if (gdb_cmd_reboot(ks))
- goto default_handle;
- break;
- case 'q': /* query command */
- gdb_cmd_query(ks);
- break;
- case 'H': /* task related */
- gdb_cmd_task(ks);
- break;
- case 'T': /* Query thread status */
- gdb_cmd_thread(ks);
- break;
- case 'z': /* Break point remove */
- case 'Z': /* Break point set */
- gdb_cmd_break(ks);
- break;
- case 'C': /* Exception passing */
- tmp = gdb_cmd_exception_pass(ks);
- if (tmp > 0)
- goto default_handle;
- if (tmp == 0)
- break;
- /* Fall through on tmp < 0 */
- case 'c': /* Continue packet */
- case 's': /* Single step packet */
- if (kgdb_contthread && kgdb_contthread != current) {
- /* Can't switch threads in kgdb */
- error_packet(remcom_out_buffer, -EINVAL);
- break;
- }
- kgdb_activate_sw_breakpoints();
- /* Fall through to default processing */
- default:
-default_handle:
- error = kgdb_arch_handle_exception(ks->ex_vector,
- ks->signo,
- ks->err_code,
- remcom_in_buffer,
- remcom_out_buffer,
- ks->linux_regs);
- /*
- * Leave cmd processing on error, detach,
- * kill, continue, or single step.
- */
- if (error >= 0 || remcom_in_buffer[0] == 'D' ||
- remcom_in_buffer[0] == 'k') {
- error = 0;
- goto kgdb_exit;
- }
-
- }
-
- /* reply to the request */
- put_packet(remcom_out_buffer);
- }
-
-kgdb_exit:
- if (ks->pass_exception)
- error = 1;
- return error;
-}
-
-static int kgdb_reenter_check(struct kgdb_state *ks)
-{
- unsigned long addr;
-
- if (atomic_read(&kgdb_active) != raw_smp_processor_id())
- return 0;
-
- /* Panic on recursive debugger calls: */
- exception_level++;
- addr = kgdb_arch_pc(ks->ex_vector, ks->linux_regs);
- kgdb_deactivate_sw_breakpoints();
-
- /*
- * If the break point removed ok at the place exception
- * occurred, try to recover and print a warning to the end
- * user because the user planted a breakpoint in a place that
- * KGDB needs in order to function.
- */
- if (kgdb_remove_sw_break(addr) == 0) {
- exception_level = 0;
- kgdb_skipexception(ks->ex_vector, ks->linux_regs);
- kgdb_activate_sw_breakpoints();
- printk(KERN_CRIT "KGDB: re-enter error: breakpoint removed %lx\n",
- addr);
- WARN_ON_ONCE(1);
-
- return 1;
- }
- remove_all_break();
- kgdb_skipexception(ks->ex_vector, ks->linux_regs);
-
- if (exception_level > 1) {
- dump_stack();
- panic("Recursive entry to debugger");
- }
-
- printk(KERN_CRIT "KGDB: re-enter exception: ALL breakpoints killed\n");
- dump_stack();
- panic("Recursive entry to debugger");
-
- return 1;
-}
-
-/*
- * kgdb_handle_exception() - main entry point from a kernel exception
- *
- * Locking hierarchy:
- * interface locks, if any (begin_session)
- * kgdb lock (kgdb_active)
- */
-int
-kgdb_handle_exception(int evector, int signo, int ecode, struct pt_regs *regs)
-{
- struct kgdb_state kgdb_var;
- struct kgdb_state *ks = &kgdb_var;
- unsigned long flags;
- int error = 0;
- int i, cpu;
-
- ks->cpu = raw_smp_processor_id();
- ks->ex_vector = evector;
- ks->signo = signo;
- ks->ex_vector = evector;
- ks->err_code = ecode;
- ks->kgdb_usethreadid = 0;
- ks->linux_regs = regs;
-
- if (kgdb_reenter_check(ks))
- return 0; /* Ouch, double exception ! */
-
-acquirelock:
- /*
- * Interrupts will be restored by the 'trap return' code, except when
- * single stepping.
- */
- local_irq_save(flags);
-
- cpu = raw_smp_processor_id();
-
- /*
- * Acquire the kgdb_active lock:
- */
- while (atomic_cmpxchg(&kgdb_active, -1, cpu) != -1)
- cpu_relax();
-
- /*
- * Do not start the debugger connection on this CPU if the last
- * instance of the exception handler wanted to come into the
- * debugger on a different CPU via a single step
- */
- if (atomic_read(&kgdb_cpu_doing_single_step) != -1 &&
- atomic_read(&kgdb_cpu_doing_single_step) != cpu) {
-
- atomic_set(&kgdb_active, -1);
- clocksource_touch_watchdog();
- local_irq_restore(flags);
-
- goto acquirelock;
- }
-
- if (!kgdb_io_ready(1)) {
- error = 1;
- goto kgdb_restore; /* No I/O connection, so resume the system */
- }
-
- /*
- * Don't enter if we have hit a removed breakpoint.
- */
- if (kgdb_skipexception(ks->ex_vector, ks->linux_regs))
- goto kgdb_restore;
-
- /* Call the I/O driver's pre_exception routine */
- if (kgdb_io_ops->pre_exception)
- kgdb_io_ops->pre_exception();
-
- kgdb_info[ks->cpu].debuggerinfo = ks->linux_regs;
- kgdb_info[ks->cpu].task = current;
-
- kgdb_disable_hw_debug(ks->linux_regs);
-
- /*
- * Get the passive CPU lock which will hold all the non-primary
- * CPU in a spin state while the debugger is active
- */
- if (!kgdb_single_step || !kgdb_contthread) {
- for (i = 0; i < NR_CPUS; i++)
- atomic_set(&passive_cpu_wait[i], 1);
- }
-
-#ifdef CONFIG_SMP
- /* Signal the other CPUs to enter kgdb_wait() */
- if (!kgdb_single_step || !kgdb_contthread)
- kgdb_roundup_cpus(flags);
-#endif
-
- /*
- * spin_lock code is good enough as a barrier so we don't
- * need one here:
- */
- atomic_set(&cpu_in_kgdb[ks->cpu], 1);
-
- /*
- * Wait for the other CPUs to be notified and be waiting for us:
- */
- for_each_online_cpu(i) {
- while (!atomic_read(&cpu_in_kgdb[i]))
- cpu_relax();
- }
-
- /*
- * At this point the primary processor is completely
- * in the debugger and all secondary CPUs are quiescent
- */
- kgdb_post_primary_code(ks->linux_regs, ks->ex_vector, ks->err_code);
- kgdb_deactivate_sw_breakpoints();
- kgdb_single_step = 0;
- kgdb_contthread = NULL;
- exception_level = 0;
-
- /* Talk to debugger with gdbserial protocol */
- error = gdb_serial_stub(ks);
-
- /* Call the I/O driver's post_exception routine */
- if (kgdb_io_ops->post_exception)
- kgdb_io_ops->post_exception();
-
- kgdb_info[ks->cpu].debuggerinfo = NULL;
- kgdb_info[ks->cpu].task = NULL;
- atomic_set(&cpu_in_kgdb[ks->cpu], 0);
-
- if (!kgdb_single_step || !kgdb_contthread) {
- for (i = NR_CPUS-1; i >= 0; i--)
- atomic_set(&passive_cpu_wait[i], 0);
- /*
- * Wait till all the CPUs have quit
- * from the debugger.
- */
- for_each_online_cpu(i) {
- while (atomic_read(&cpu_in_kgdb[i]))
- cpu_relax();
- }
- }
-
-kgdb_restore:
- /* Free kgdb_active */
- atomic_set(&kgdb_active, -1);
- clocksource_touch_watchdog();
- local_irq_restore(flags);
-
- return error;
-}
-
-int kgdb_nmicallback(int cpu, void *regs)
-{
-#ifdef CONFIG_SMP
- if (!atomic_read(&cpu_in_kgdb[cpu]) &&
- atomic_read(&kgdb_active) != cpu) {
- kgdb_wait((struct pt_regs *)regs);
- return 0;
- }
-#endif
- return 1;
-}
-
-void kgdb_console_write(struct console *co, const char *s, unsigned count)
-{
- unsigned long flags;
-
- /* If we're debugging, or KGDB has not connected, don't try
- * and print. */
- if (!kgdb_connected || atomic_read(&kgdb_active) != -1)
- return;
-
- local_irq_save(flags);
- kgdb_msg_write(s, count);
- local_irq_restore(flags);
-}
-
-static struct console kgdbcons = {
- .name = "kgdb",
- .write = kgdb_console_write,
- .flags = CON_PRINTBUFFER | CON_ENABLED,
- .index = -1,
-};
-
-#ifdef CONFIG_MAGIC_SYSRQ
-static void sysrq_handle_gdb(int key, struct tty_struct *tty)
-{
- if (!kgdb_io_ops) {
- printk(KERN_CRIT "ERROR: No KGDB I/O module available\n");
- return;
- }
- if (!kgdb_connected)
- printk(KERN_CRIT "Entering KGDB\n");
-
- kgdb_breakpoint();
-}
-
-static struct sysrq_key_op sysrq_gdb_op = {
- .handler = sysrq_handle_gdb,
- .help_msg = "Gdb",
- .action_msg = "GDB",
-};
-#endif
-
-static void kgdb_register_callbacks(void)
-{
- if (!kgdb_io_module_registered) {
- kgdb_io_module_registered = 1;
- kgdb_arch_init();
-#ifdef CONFIG_MAGIC_SYSRQ
- register_sysrq_key('g', &sysrq_gdb_op);
-#endif
- if (kgdb_use_con && !kgdb_con_registered) {
- register_console(&kgdbcons);
- kgdb_con_registered = 1;
- }
- }
-}
-
-static void kgdb_unregister_callbacks(void)
-{
- /*
- * When this routine is called KGDB should unregister from the
- * panic handler and clean up, making sure it is not handling any
- * break exceptions at the time.
- */
- if (kgdb_io_module_registered) {
- kgdb_io_module_registered = 0;
- kgdb_arch_exit();
-#ifdef CONFIG_MAGIC_SYSRQ
- unregister_sysrq_key('g', &sysrq_gdb_op);
-#endif
- if (kgdb_con_registered) {
- unregister_console(&kgdbcons);
- kgdb_con_registered = 0;
- }
- }
-}
-
-static void kgdb_initial_breakpoint(void)
-{
- kgdb_break_asap = 0;
-
- printk(KERN_CRIT "kgdb: Waiting for connection from remote gdb...\n");
- kgdb_breakpoint();
-}
-
-/**
- * kkgdb_register_io_module - register KGDB IO module
- * @new_kgdb_io_ops: the io ops vector
- *
- * Register it with the KGDB core.
- */
-int kgdb_register_io_module(struct kgdb_io *new_kgdb_io_ops)
-{
- int err;
-
- spin_lock(&kgdb_registration_lock);
-
- if (kgdb_io_ops) {
- spin_unlock(&kgdb_registration_lock);
-
- printk(KERN_ERR "kgdb: Another I/O driver is already "
- "registered with KGDB.\n");
- return -EBUSY;
- }
-
- if (new_kgdb_io_ops->init) {
- err = new_kgdb_io_ops->init();
- if (err) {
- spin_unlock(&kgdb_registration_lock);
- return err;
- }
- }
-
- kgdb_io_ops = new_kgdb_io_ops;
-
- spin_unlock(&kgdb_registration_lock);
-
- printk(KERN_INFO "kgdb: Registered I/O driver %s.\n",
- new_kgdb_io_ops->name);
-
- /* Arm KGDB now. */
- kgdb_register_callbacks();
-
- if (kgdb_break_asap)
- kgdb_initial_breakpoint();
-
- return 0;
-}
-EXPORT_SYMBOL_GPL(kgdb_register_io_module);
-
-/**
- * kkgdb_unregister_io_module - unregister KGDB IO module
- * @old_kgdb_io_ops: the io ops vector
- *
- * Unregister it with the KGDB core.
- */
-void kgdb_unregister_io_module(struct kgdb_io *old_kgdb_io_ops)
-{
- BUG_ON(kgdb_connected);
-
- /*
- * KGDB is no longer able to communicate out, so
- * unregister our callbacks and reset state.
- */
- kgdb_unregister_callbacks();
-
- spin_lock(&kgdb_registration_lock);
-
- WARN_ON_ONCE(kgdb_io_ops != old_kgdb_io_ops);
- kgdb_io_ops = NULL;
-
- spin_unlock(&kgdb_registration_lock);
-
- printk(KERN_INFO
- "kgdb: Unregistered I/O driver %s, debugger disabled.\n",
- old_kgdb_io_ops->name);
-}
-EXPORT_SYMBOL_GPL(kgdb_unregister_io_module);
-
-/**
- * kgdb_breakpoint - generate breakpoint exception
- *
- * This function will generate a breakpoint exception. It is used at the
- * beginning of a program to sync up with a debugger and can be used
- * otherwise as a quick means to stop program execution and "break" into
- * the debugger.
- */
-void kgdb_breakpoint(void)
-{
- atomic_set(&kgdb_setting_breakpoint, 1);
- wmb(); /* Sync point before breakpoint */
- arch_kgdb_breakpoint();
- wmb(); /* Sync point after breakpoint */
- atomic_set(&kgdb_setting_breakpoint, 0);
-}
-EXPORT_SYMBOL_GPL(kgdb_breakpoint);
-
-static int __init opt_kgdb_wait(char *str)
-{
- kgdb_break_asap = 1;
-
- if (kgdb_io_module_registered)
- kgdb_initial_breakpoint();
-
- return 0;
-}
-
-early_param("kgdbwait", opt_kgdb_wait);
diff --git a/lib/kgdb.c b/lib/kgdb.c
new file mode 100644
index 0000000..a453764
--- /dev/null
+++ b/lib/kgdb.c
@@ -0,0 +1,1680 @@
+/*
+ * KGDB stub.
+ *
+ * Maintainer: Jason Wessel <jason.wessel@windriver.com>
+ *
+ * Copyright (C) 2000-2001 VERITAS Software Corporation.
+ * Copyright (C) 2002-2004 Timesys Corporation
+ * Copyright (C) 2003-2004 Amit S. Kale <amitkale@linsyssoft.com>
+ * Copyright (C) 2004 Pavel Machek <pavel@suse.cz>
+ * Copyright (C) 2004-2006 Tom Rini <trini@kernel.crashing.org>
+ * Copyright (C) 2004-2006 LinSysSoft Technologies Pvt. Ltd.
+ * Copyright (C) 2005-2008 Wind River Systems, Inc.
+ * Copyright (C) 2007 MontaVista Software, Inc.
+ * Copyright (C) 2008 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
+ *
+ * Contributors at various stages not listed above:
+ * Jason Wessel ( jason.wessel@windriver.com )
+ * George Anzinger <george@mvista.com>
+ * Anurekh Saxena (anurekh.saxena@timesys.com)
+ * Lake Stevens Instrument Division (Glenn Engel)
+ * Jim Kingdon, Cygnus Support.
+ *
+ * Original KGDB stub: David Grothe <dave@gcom.com>,
+ * Tigran Aivazian <tigran@sco.com>
+ *
+ * This file is licensed under the terms of the GNU General Public License
+ * version 2. This program is licensed "as is" without any warranty of any
+ * kind, whether express or implied.
+ */
+#include <linux/pid_namespace.h>
+#include <linux/clocksource.h>
+#include <linux/interrupt.h>
+#include <linux/spinlock.h>
+#include <linux/console.h>
+#include <linux/threads.h>
+#include <linux/uaccess.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/ptrace.h>
+#include <linux/reboot.h>
+#include <linux/string.h>
+#include <linux/delay.h>
+#include <linux/sched.h>
+#include <linux/sysrq.h>
+#include <linux/init.h>
+#include <linux/kgdb.h>
+#include <linux/pid.h>
+#include <linux/smp.h>
+#include <linux/mm.h>
+
+#include <asm/cacheflush.h>
+#include <asm/byteorder.h>
+#include <asm/atomic.h>
+#include <asm/system.h>
+
+static int kgdb_break_asap;
+
+struct kgdb_state {
+ int ex_vector;
+ int signo;
+ int err_code;
+ int cpu;
+ int pass_exception;
+ long threadid;
+ long kgdb_usethreadid;
+ struct pt_regs *linux_regs;
+};
+
+static struct debuggerinfo_struct {
+ void *debuggerinfo;
+ struct task_struct *task;
+} kgdb_info[NR_CPUS];
+
+/**
+ * kgdb_connected - Is a host GDB connected to us?
+ */
+int kgdb_connected;
+EXPORT_SYMBOL_GPL(kgdb_connected);
+
+/* All the KGDB handlers are installed */
+static int kgdb_io_module_registered;
+
+/* Guard for recursive entry */
+static int exception_level;
+
+static struct kgdb_io *kgdb_io_ops;
+static DEFINE_SPINLOCK(kgdb_registration_lock);
+
+/* kgdb console driver is loaded */
+static int kgdb_con_registered;
+/* determine if kgdb console output should be used */
+static int kgdb_use_con;
+
+static int __init opt_kgdb_con(char *str)
+{
+ kgdb_use_con = 1;
+ return 0;
+}
+
+early_param("kgdbcon", opt_kgdb_con);
+
+module_param(kgdb_use_con, int, 0644);
+
+/*
+ * Holds information about breakpoints in a kernel. These breakpoints are
+ * added and removed by gdb.
+ */
+static struct kgdb_bkpt kgdb_break[KGDB_MAX_BREAKPOINTS] = {
+ [0 ... KGDB_MAX_BREAKPOINTS-1] = { .state = BP_UNDEFINED }
+};
+
+/*
+ * The CPU# of the active CPU, or -1 if none:
+ */
+atomic_t kgdb_active = ATOMIC_INIT(-1);
+
+/*
+ * We use NR_CPUs not PERCPU, in case kgdb is used to debug early
+ * bootup code (which might not have percpu set up yet):
+ */
+static atomic_t passive_cpu_wait[NR_CPUS];
+static atomic_t cpu_in_kgdb[NR_CPUS];
+atomic_t kgdb_setting_breakpoint;
+
+struct task_struct *kgdb_usethread;
+struct task_struct *kgdb_contthread;
+
+int kgdb_single_step;
+
+/* Our I/O buffers. */
+static char remcom_in_buffer[BUFMAX];
+static char remcom_out_buffer[BUFMAX];
+
+/* Storage for the registers, in GDB format. */
+static unsigned long gdb_regs[(NUMREGBYTES +
+ sizeof(unsigned long) - 1) /
+ sizeof(unsigned long)];
+
+/* to keep track of the CPU which is doing the single stepping*/
+atomic_t kgdb_cpu_doing_single_step = ATOMIC_INIT(-1);
+
+/*
+ * Finally, some KGDB code :-)
+ */
+
+/*
+ * Weak aliases for breakpoint management,
+ * can be overriden by architectures when needed:
+ */
+int __weak kgdb_validate_break_address(unsigned long addr)
+{
+ char tmp_variable[BREAK_INSTR_SIZE];
+
+ return probe_kernel_read(tmp_variable, (char *)addr, BREAK_INSTR_SIZE);
+}
+
+int __weak kgdb_arch_set_breakpoint(unsigned long addr, char *saved_instr)
+{
+ int err;
+
+ err = probe_kernel_read(saved_instr, (char *)addr, BREAK_INSTR_SIZE);
+ if (err)
+ return err;
+
+ return probe_kernel_write((char *)addr, arch_kgdb_ops.gdb_bpt_instr,
+ BREAK_INSTR_SIZE);
+}
+
+int __weak kgdb_arch_remove_breakpoint(unsigned long addr, char *bundle)
+{
+ return probe_kernel_write((char *)addr,
+ (char *)bundle, BREAK_INSTR_SIZE);
+}
+
+unsigned long __weak kgdb_arch_pc(int exception, struct pt_regs *regs)
+{
+ return instruction_pointer(regs);
+}
+
+int __weak kgdb_arch_init(void)
+{
+ return 0;
+}
+
+/**
+ * kgdb_disable_hw_debug - Disable hardware debugging while we in kgdb.
+ * @regs: Current &struct pt_regs.
+ *
+ * This function will be called if the particular architecture must
+ * disable hardware debugging while it is processing gdb packets or
+ * handling exception.
+ */
+void __weak kgdb_disable_hw_debug(struct pt_regs *regs)
+{
+}
+
+/*
+ * GDB remote protocol parser:
+ */
+
+static const char hexchars[] = "0123456789abcdef";
+
+static int hex(char ch)
+{
+ if ((ch >= 'a') && (ch <= 'f'))
+ return ch - 'a' + 10;
+ if ((ch >= '0') && (ch <= '9'))
+ return ch - '0';
+ if ((ch >= 'A') && (ch <= 'F'))
+ return ch - 'A' + 10;
+ return -1;
+}
+
+/* scan for the sequence $<data>#<checksum> */
+static void get_packet(char *buffer)
+{
+ unsigned char checksum;
+ unsigned char xmitcsum;
+ int count;
+ char ch;
+
+ do {
+ /*
+ * Spin and wait around for the start character, ignore all
+ * other characters:
+ */
+ while ((ch = (kgdb_io_ops->read_char())) != '$')
+ /* nothing */;
+
+ kgdb_connected = 1;
+ checksum = 0;
+ xmitcsum = -1;
+
+ count = 0;
+
+ /*
+ * now, read until a # or end of buffer is found:
+ */
+ while (count < (BUFMAX - 1)) {
+ ch = kgdb_io_ops->read_char();
+ if (ch == '#')
+ break;
+ checksum = checksum + ch;
+ buffer[count] = ch;
+ count = count + 1;
+ }
+ buffer[count] = 0;
+
+ if (ch == '#') {
+ xmitcsum = hex(kgdb_io_ops->read_char()) << 4;
+ xmitcsum += hex(kgdb_io_ops->read_char());
+
+ if (checksum != xmitcsum)
+ /* failed checksum */
+ kgdb_io_ops->write_char('-');
+ else
+ /* successful transfer */
+ kgdb_io_ops->write_char('+');
+ if (kgdb_io_ops->flush)
+ kgdb_io_ops->flush();
+ }
+ } while (checksum != xmitcsum);
+}
+
+/*
+ * Send the packet in buffer.
+ * Check for gdb connection if asked for.
+ */
+static void put_packet(char *buffer)
+{
+ unsigned char checksum;
+ int count;
+ char ch;
+
+ /*
+ * $<packet info>#<checksum>.
+ */
+ while (1) {
+ kgdb_io_ops->write_char('$');
+ checksum = 0;
+ count = 0;
+
+ while ((ch = buffer[count])) {
+ kgdb_io_ops->write_char(ch);
+ checksum += ch;
+ count++;
+ }
+
+ kgdb_io_ops->write_char('#');
+ kgdb_io_ops->write_char(hexchars[checksum >> 4]);
+ kgdb_io_ops->write_char(hexchars[checksum & 0xf]);
+ if (kgdb_io_ops->flush)
+ kgdb_io_ops->flush();
+
+ /* Now see what we get in reply. */
+ ch = kgdb_io_ops->read_char();
+
+ if (ch == 3)
+ ch = kgdb_io_ops->read_char();
+
+ /* If we get an ACK, we are done. */
+ if (ch == '+')
+ return;
+
+ /*
+ * If we get the start of another packet, this means
+ * that GDB is attempting to reconnect. We will NAK
+ * the packet being sent, and stop trying to send this
+ * packet.
+ */
+ if (ch == '$') {
+ kgdb_io_ops->write_char('-');
+ if (kgdb_io_ops->flush)
+ kgdb_io_ops->flush();
+ return;
+ }
+ }
+}
+
+static char *pack_hex_byte(char *pkt, u8 byte)
+{
+ *pkt++ = hexchars[byte >> 4];
+ *pkt++ = hexchars[byte & 0xf];
+
+ return pkt;
+}
+
+/*
+ * Convert the memory pointed to by mem into hex, placing result in buf.
+ * Return a pointer to the last char put in buf (null). May return an error.
+ */
+int kgdb_mem2hex(char *mem, char *buf, int count)
+{
+ char *tmp;
+ int err;
+
+ /*
+ * We use the upper half of buf as an intermediate buffer for the
+ * raw memory copy. Hex conversion will work against this one.
+ */
+ tmp = buf + count;
+
+ err = probe_kernel_read(tmp, mem, count);
+ if (!err) {
+ while (count > 0) {
+ buf = pack_hex_byte(buf, *tmp);
+ tmp++;
+ count--;
+ }
+
+ *buf = 0;
+ }
+
+ return err;
+}
+
+/*
+ * Copy the binary array pointed to by buf into mem. Fix $, #, and
+ * 0x7d escaped with 0x7d. Return a pointer to the character after
+ * the last byte written.
+ */
+static int kgdb_ebin2mem(char *buf, char *mem, int count)
+{
+ int err = 0;
+ char c;
+
+ while (count-- > 0) {
+ c = *buf++;
+ if (c == 0x7d)
+ c = *buf++ ^ 0x20;
+
+ err = probe_kernel_write(mem, &c, 1);
+ if (err)
+ break;
+
+ mem++;
+ }
+
+ return err;
+}
+
+/*
+ * Convert the hex array pointed to by buf into binary to be placed in mem.
+ * Return a pointer to the character AFTER the last byte written.
+ * May return an error.
+ */
+int kgdb_hex2mem(char *buf, char *mem, int count)
+{
+ char *tmp_raw;
+ char *tmp_hex;
+
+ /*
+ * We use the upper half of buf as an intermediate buffer for the
+ * raw memory that is converted from hex.
+ */
+ tmp_raw = buf + count * 2;
+
+ tmp_hex = tmp_raw - 1;
+ while (tmp_hex >= buf) {
+ tmp_raw--;
+ *tmp_raw = hex(*tmp_hex--);
+ *tmp_raw |= hex(*tmp_hex--) << 4;
+ }
+
+ return probe_kernel_write(mem, tmp_raw, count);
+}
+
+/*
+ * While we find nice hex chars, build a long_val.
+ * Return number of chars processed.
+ */
+int kgdb_hex2long(char **ptr, long *long_val)
+{
+ int hex_val;
+ int num = 0;
+
+ *long_val = 0;
+
+ while (**ptr) {
+ hex_val = hex(**ptr);
+ if (hex_val < 0)
+ break;
+
+ *long_val = (*long_val << 4) | hex_val;
+ num++;
+ (*ptr)++;
+ }
+
+ return num;
+}
+
+/* Write memory due to an 'M' or 'X' packet. */
+static int write_mem_msg(int binary)
+{
+ char *ptr = &remcom_in_buffer[1];
+ unsigned long addr;
+ unsigned long length;
+ int err;
+
+ if (kgdb_hex2long(&ptr, &addr) > 0 && *(ptr++) == ',' &&
+ kgdb_hex2long(&ptr, &length) > 0 && *(ptr++) == ':') {
+ if (binary)
+ err = kgdb_ebin2mem(ptr, (char *)addr, length);
+ else
+ err = kgdb_hex2mem(ptr, (char *)addr, length);
+ if (err)
+ return err;
+ if (CACHE_FLUSH_IS_SAFE)
+ flush_icache_range(addr, addr + length + 1);
+ return 0;
+ }
+
+ return -EINVAL;
+}
+
+static void error_packet(char *pkt, int error)
+{
+ error = -error;
+ pkt[0] = 'E';
+ pkt[1] = hexchars[(error / 10)];
+ pkt[2] = hexchars[(error % 10)];
+ pkt[3] = '\0';
+}
+
+/*
+ * Thread ID accessors. We represent a flat TID space to GDB, where
+ * the per CPU idle threads (which under Linux all have PID 0) are
+ * remapped to negative TIDs.
+ */
+
+#define BUF_THREAD_ID_SIZE 16
+
+static char *pack_threadid(char *pkt, unsigned char *id)
+{
+ char *limit;
+
+ limit = pkt + BUF_THREAD_ID_SIZE;
+ while (pkt < limit)
+ pkt = pack_hex_byte(pkt, *id++);
+
+ return pkt;
+}
+
+static void int_to_threadref(unsigned char *id, int value)
+{
+ unsigned char *scan;
+ int i = 4;
+
+ scan = (unsigned char *)id;
+ while (i--)
+ *scan++ = 0;
+ *scan++ = (value >> 24) & 0xff;
+ *scan++ = (value >> 16) & 0xff;
+ *scan++ = (value >> 8) & 0xff;
+ *scan++ = (value & 0xff);
+}
+
+static struct task_struct *getthread(struct pt_regs *regs, int tid)
+{
+ /*
+ * Non-positive TIDs are remapped idle tasks:
+ */
+ if (tid <= 0)
+ return idle_task(-tid);
+
+ /*
+ * find_task_by_pid() does not take the tasklist lock anymore
+ * but is nicely RCU locked - hence is a pretty resilient
+ * thing to use:
+ */
+ return find_task_by_pid(tid);
+}
+
+/*
+ * CPU debug state control:
+ */
+
+#ifdef CONFIG_SMP
+static void kgdb_wait(struct pt_regs *regs)
+{
+ unsigned long flags;
+ int cpu;
+
+ local_irq_save(flags);
+ cpu = raw_smp_processor_id();
+ kgdb_info[cpu].debuggerinfo = regs;
+ kgdb_info[cpu].task = current;
+ /*
+ * Make sure the above info reaches the primary CPU before
+ * our cpu_in_kgdb[] flag setting does:
+ */
+ smp_wmb();
+ atomic_set(&cpu_in_kgdb[cpu], 1);
+
+ /*
+ * The primary CPU must be active to enter here, but this is
+ * guard in case the primary CPU had not been selected if
+ * this was an entry via nmi.
+ */
+ while (atomic_read(&kgdb_active) == -1)
+ cpu_relax();
+
+ /* Wait till primary CPU goes completely into the debugger. */
+ while (!atomic_read(&cpu_in_kgdb[atomic_read(&kgdb_active)]))
+ cpu_relax();
+
+ /* Wait till primary CPU is done with debugging */
+ while (atomic_read(&passive_cpu_wait[cpu]))
+ cpu_relax();
+
+ kgdb_info[cpu].debuggerinfo = NULL;
+ kgdb_info[cpu].task = NULL;
+
+ /* fix up hardware debug registers on local cpu */
+ if (arch_kgdb_ops.correct_hw_break)
+ arch_kgdb_ops.correct_hw_break();
+
+ /* Signal the primary CPU that we are done: */
+ atomic_set(&cpu_in_kgdb[cpu], 0);
+ clocksource_touch_watchdog();
+ local_irq_restore(flags);
+}
+#endif
+
+/*
+ * Some architectures need cache flushes when we set/clear a
+ * breakpoint:
+ */
+static void kgdb_flush_swbreak_addr(unsigned long addr)
+{
+ if (!CACHE_FLUSH_IS_SAFE)
+ return;
+
+ if (current->mm) {
+ flush_cache_range(current->mm->mmap_cache,
+ addr, addr + BREAK_INSTR_SIZE);
+ } else {
+ flush_icache_range(addr, addr + BREAK_INSTR_SIZE);
+ }
+}
+
+/*
+ * SW breakpoint management:
+ */
+static int kgdb_activate_sw_breakpoints(void)
+{
+ unsigned long addr;
+ int error = 0;
+ int i;
+
+ for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) {
+ if (kgdb_break[i].state != BP_SET)
+ continue;
+
+ addr = kgdb_break[i].bpt_addr;
+ error = kgdb_arch_set_breakpoint(addr,
+ kgdb_break[i].saved_instr);
+ if (error)
+ return error;
+
+ kgdb_flush_swbreak_addr(addr);
+ kgdb_break[i].state = BP_ACTIVE;
+ }
+ return 0;
+}
+
+static int kgdb_set_sw_break(unsigned long addr)
+{
+ int err = kgdb_validate_break_address(addr);
+ int breakno = -1;
+ int i;
+
+ if (err)
+ return err;
+
+ for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) {
+ if ((kgdb_break[i].state == BP_SET) &&
+ (kgdb_break[i].bpt_addr == addr))
+ return -EEXIST;
+ }
+ for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) {
+ if (kgdb_break[i].state == BP_REMOVED &&
+ kgdb_break[i].bpt_addr == addr) {
+ breakno = i;
+ break;
+ }
+ }
+
+ if (breakno == -1) {
+ for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) {
+ if (kgdb_break[i].state == BP_UNDEFINED) {
+ breakno = i;
+ break;
+ }
+ }
+ }
+
+ if (breakno == -1)
+ return -E2BIG;
+
+ kgdb_break[breakno].state = BP_SET;
+ kgdb_break[breakno].type = BP_BREAKPOINT;
+ kgdb_break[breakno].bpt_addr = addr;
+
+ return 0;
+}
+
+static int kgdb_deactivate_sw_breakpoints(void)
+{
+ unsigned long addr;
+ int error = 0;
+ int i;
+
+ for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) {
+ if (kgdb_break[i].state != BP_ACTIVE)
+ continue;
+ addr = kgdb_break[i].bpt_addr;
+ error = kgdb_arch_remove_breakpoint(addr,
+ kgdb_break[i].saved_instr);
+ if (error)
+ return error;
+
+ kgdb_flush_swbreak_addr(addr);
+ kgdb_break[i].state = BP_SET;
+ }
+ return 0;
+}
+
+static int kgdb_remove_sw_break(unsigned long addr)
+{
+ int i;
+
+ for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) {
+ if ((kgdb_break[i].state == BP_SET) &&
+ (kgdb_break[i].bpt_addr == addr)) {
+ kgdb_break[i].state = BP_REMOVED;
+ return 0;
+ }
+ }
+ return -ENOENT;
+}
+
+int kgdb_isremovedbreak(unsigned long addr)
+{
+ int i;
+
+ for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) {
+ if ((kgdb_break[i].state == BP_REMOVED) &&
+ (kgdb_break[i].bpt_addr == addr))
+ return 1;
+ }
+ return 0;
+}
+
+int remove_all_break(void)
+{
+ unsigned long addr;
+ int error;
+ int i;
+
+ /* Clear memory breakpoints. */
+ for (i = 0; i < KGDB_MAX_BREAKPOINTS; i++) {
+ if (kgdb_break[i].state != BP_SET)
+ continue;
+ addr = kgdb_break[i].bpt_addr;
+ error = kgdb_arch_remove_breakpoint(addr,
+ kgdb_break[i].saved_instr);
+ if (error)
+ return error;
+ kgdb_break[i].state = BP_REMOVED;
+ }
+
+ /* Clear hardware breakpoints. */
+ if (arch_kgdb_ops.remove_all_hw_break)
+ arch_kgdb_ops.remove_all_hw_break();
+
+ return 0;
+}
+
+/*
+ * Remap normal tasks to their real PID, idle tasks to -1 ... -NR_CPUs:
+ */
+static inline int shadow_pid(int realpid)
+{
+ if (realpid)
+ return realpid;
+
+ return -1-raw_smp_processor_id();
+}
+
+static char gdbmsgbuf[BUFMAX + 1];
+
+static void kgdb_msg_write(const char *s, int len)
+{
+ char *bufptr;
+ int wcount;
+ int i;
+
+ /* 'O'utput */
+ gdbmsgbuf[0] = 'O';
+
+ /* Fill and send buffers... */
+ while (len > 0) {
+ bufptr = gdbmsgbuf + 1;
+
+ /* Calculate how many this time */
+ if ((len << 1) > (BUFMAX - 2))
+ wcount = (BUFMAX - 2) >> 1;
+ else
+ wcount = len;
+
+ /* Pack in hex chars */
+ for (i = 0; i < wcount; i++)
+ bufptr = pack_hex_byte(bufptr, s[i]);
+ *bufptr = '\0';
+
+ /* Move up */
+ s += wcount;
+ len -= wcount;
+
+ /* Write packet */
+ put_packet(gdbmsgbuf);
+ }
+}
+
+/*
+ * Return true if there is a valid kgdb I/O module. Also if no
+ * debugger is attached a message can be printed to the console about
+ * waiting for the debugger to attach.
+ *
+ * The print_wait argument is only to be true when called from inside
+ * the core kgdb_handle_exception, because it will wait for the
+ * debugger to attach.
+ */
+static int kgdb_io_ready(int print_wait)
+{
+ if (!kgdb_io_ops)
+ return 0;
+ if (kgdb_connected)
+ return 1;
+ if (atomic_read(&kgdb_setting_breakpoint))
+ return 1;
+ if (print_wait)
+ printk(KERN_CRIT "KGDB: Waiting for remote debugger\n");
+ return 1;
+}
+
+/*
+ * All the functions that start with gdb_cmd are the various
+ * operations to implement the handlers for the gdbserial protocol
+ * where KGDB is communicating with an external debugger
+ */
+
+/* Handle the '?' status packets */
+static void gdb_cmd_status(struct kgdb_state *ks)
+{
+ /*
+ * We know that this packet is only sent
+ * during initial connect. So to be safe,
+ * we clear out our breakpoints now in case
+ * GDB is reconnecting.
+ */
+ remove_all_break();
+
+ remcom_out_buffer[0] = 'S';
+ pack_hex_byte(&remcom_out_buffer[1], ks->signo);
+}
+
+/* Handle the 'g' get registers request */
+static void gdb_cmd_getregs(struct kgdb_state *ks)
+{
+ struct task_struct *thread;
+ void *local_debuggerinfo;
+ int i;
+
+ thread = kgdb_usethread;
+ if (!thread) {
+ thread = kgdb_info[ks->cpu].task;
+ local_debuggerinfo = kgdb_info[ks->cpu].debuggerinfo;
+ } else {
+ local_debuggerinfo = NULL;
+ for (i = 0; i < NR_CPUS; i++) {
+ /*
+ * Try to find the task on some other
+ * or possibly this node if we do not
+ * find the matching task then we try
+ * to approximate the results.
+ */
+ if (thread == kgdb_info[i].task)
+ local_debuggerinfo = kgdb_info[i].debuggerinfo;
+ }
+ }
+
+ /*
+ * All threads that don't have debuggerinfo should be
+ * in __schedule() sleeping, since all other CPUs
+ * are in kgdb_wait, and thus have debuggerinfo.
+ */
+ if (local_debuggerinfo) {
+ pt_regs_to_gdb_regs(gdb_regs, local_debuggerinfo);
+ } else {
+ /*
+ * Pull stuff saved during switch_to; nothing
+ * else is accessible (or even particularly
+ * relevant).
+ *
+ * This should be enough for a stack trace.
+ */
+ sleeping_thread_to_gdb_regs(gdb_regs, thread);
+ }
+ kgdb_mem2hex((char *)gdb_regs, remcom_out_buffer, NUMREGBYTES);
+}
+
+/* Handle the 'G' set registers request */
+static void gdb_cmd_setregs(struct kgdb_state *ks)
+{
+ kgdb_hex2mem(&remcom_in_buffer[1], (char *)gdb_regs, NUMREGBYTES);
+
+ if (kgdb_usethread && kgdb_usethread != current) {
+ error_packet(remcom_out_buffer, -EINVAL);
+ } else {
+ gdb_regs_to_pt_regs(gdb_regs, ks->linux_regs);
+ strcpy(remcom_out_buffer, "OK");
+ }
+}
+
+/* Handle the 'm' memory read bytes */
+static void gdb_cmd_memread(struct kgdb_state *ks)
+{
+ char *ptr = &remcom_in_buffer[1];
+ unsigned long length;
+ unsigned long addr;
+ int err;
+
+ if (kgdb_hex2long(&ptr, &addr) > 0 && *ptr++ == ',' &&
+ kgdb_hex2long(&ptr, &length) > 0) {
+ err = kgdb_mem2hex((char *)addr, remcom_out_buffer, length);
+ if (err)
+ error_packet(remcom_out_buffer, err);
+ } else {
+ error_packet(remcom_out_buffer, -EINVAL);
+ }
+}
+
+/* Handle the 'M' memory write bytes */
+static void gdb_cmd_memwrite(struct kgdb_state *ks)
+{
+ int err = write_mem_msg(0);
+
+ if (err)
+ error_packet(remcom_out_buffer, err);
+ else
+ strcpy(remcom_out_buffer, "OK");
+}
+
+/* Handle the 'X' memory binary write bytes */
+static void gdb_cmd_binwrite(struct kgdb_state *ks)
+{
+ int err = write_mem_msg(1);
+
+ if (err)
+ error_packet(remcom_out_buffer, err);
+ else
+ strcpy(remcom_out_buffer, "OK");
+}
+
+/* Handle the 'D' or 'k', detach or kill packets */
+static void gdb_cmd_detachkill(struct kgdb_state *ks)
+{
+ int error;
+
+ /* The detach case */
+ if (remcom_in_buffer[0] == 'D') {
+ error = remove_all_break();
+ if (error < 0) {
+ error_packet(remcom_out_buffer, error);
+ } else {
+ strcpy(remcom_out_buffer, "OK");
+ kgdb_connected = 0;
+ }
+ put_packet(remcom_out_buffer);
+ } else {
+ /*
+ * Assume the kill case, with no exit code checking,
+ * trying to force detach the debugger:
+ */
+ remove_all_break();
+ kgdb_connected = 0;
+ }
+}
+
+/* Handle the 'R' reboot packets */
+static int gdb_cmd_reboot(struct kgdb_state *ks)
+{
+ /* For now, only honor R0 */
+ if (strcmp(remcom_in_buffer, "R0") == 0) {
+ printk(KERN_CRIT "Executing emergency reboot\n");
+ strcpy(remcom_out_buffer, "OK");
+ put_packet(remcom_out_buffer);
+
+ /*
+ * Execution should not return from
+ * machine_emergency_restart()
+ */
+ machine_emergency_restart();
+ kgdb_connected = 0;
+
+ return 1;
+ }
+ return 0;
+}
+
+/* Handle the 'q' query packets */
+static void gdb_cmd_query(struct kgdb_state *ks)
+{
+ struct task_struct *thread;
+ unsigned char thref[8];
+ char *ptr;
+ int i;
+
+ switch (remcom_in_buffer[1]) {
+ case 's':
+ case 'f':
+ if (memcmp(remcom_in_buffer + 2, "ThreadInfo", 10)) {
+ error_packet(remcom_out_buffer, -EINVAL);
+ break;
+ }
+
+ if (remcom_in_buffer[1] == 'f')
+ ks->threadid = 1;
+
+ remcom_out_buffer[0] = 'm';
+ ptr = remcom_out_buffer + 1;
+
+ for (i = 0; i < 17; ks->threadid++) {
+ thread = getthread(ks->linux_regs, ks->threadid);
+ if (thread) {
+ int_to_threadref(thref, ks->threadid);
+ pack_threadid(ptr, thref);
+ ptr += BUF_THREAD_ID_SIZE;
+ *(ptr++) = ',';
+ i++;
+ }
+ }
+ *(--ptr) = '\0';
+ break;
+
+ case 'C':
+ /* Current thread id */
+ strcpy(remcom_out_buffer, "QC");
+ ks->threadid = shadow_pid(current->pid);
+ int_to_threadref(thref, ks->threadid);
+ pack_threadid(remcom_out_buffer + 2, thref);
+ break;
+ case 'T':
+ if (memcmp(remcom_in_buffer + 1, "ThreadExtraInfo,", 16)) {
+ error_packet(remcom_out_buffer, -EINVAL);
+ break;
+ }
+ ks->threadid = 0;
+ ptr = remcom_in_buffer + 17;
+ kgdb_hex2long(&ptr, &ks->threadid);
+ if (!getthread(ks->linux_regs, ks->threadid)) {
+ error_packet(remcom_out_buffer, -EINVAL);
+ break;
+ }
+ if (ks->threadid > 0) {
+ kgdb_mem2hex(getthread(ks->linux_regs,
+ ks->threadid)->comm,
+ remcom_out_buffer, 16);
+ } else {
+ static char tmpstr[23 + BUF_THREAD_ID_SIZE];
+
+ sprintf(tmpstr, "Shadow task %d for pid 0",
+ (int)(-ks->threadid-1));
+ kgdb_mem2hex(tmpstr, remcom_out_buffer, strlen(tmpstr));
+ }
+ break;
+ }
+}
+
+/* Handle the 'H' task query packets */
+static void gdb_cmd_task(struct kgdb_state *ks)
+{
+ struct task_struct *thread;
+ char *ptr;
+
+ switch (remcom_in_buffer[1]) {
+ case 'g':
+ ptr = &remcom_in_buffer[2];
+ kgdb_hex2long(&ptr, &ks->threadid);
+ thread = getthread(ks->linux_regs, ks->threadid);
+ if (!thread && ks->threadid > 0) {
+ error_packet(remcom_out_buffer, -EINVAL);
+ break;
+ }
+ kgdb_usethread = thread;
+ ks->kgdb_usethreadid = ks->threadid;
+ strcpy(remcom_out_buffer, "OK");
+ break;
+ case 'c':
+ ptr = &remcom_in_buffer[2];
+ kgdb_hex2long(&ptr, &ks->threadid);
+ if (!ks->threadid) {
+ kgdb_contthread = NULL;
+ } else {
+ thread = getthread(ks->linux_regs, ks->threadid);
+ if (!thread && ks->threadid > 0) {
+ error_packet(remcom_out_buffer, -EINVAL);
+ break;
+ }
+ kgdb_contthread = thread;
+ }
+ strcpy(remcom_out_buffer, "OK");
+ break;
+ }
+}
+
+/* Handle the 'T' thread query packets */
+static void gdb_cmd_thread(struct kgdb_state *ks)
+{
+ char *ptr = &remcom_in_buffer[1];
+ struct task_struct *thread;
+
+ kgdb_hex2long(&ptr, &ks->threadid);
+ thread = getthread(ks->linux_regs, ks->threadid);
+ if (thread)
+ strcpy(remcom_out_buffer, "OK");
+ else
+ error_packet(remcom_out_buffer, -EINVAL);
+}
+
+/* Handle the 'z' or 'Z' breakpoint remove or set packets */
+static void gdb_cmd_break(struct kgdb_state *ks)
+{
+ /*
+ * Since GDB-5.3, it's been drafted that '0' is a software
+ * breakpoint, '1' is a hardware breakpoint, so let's do that.
+ */
+ char *bpt_type = &remcom_in_buffer[1];
+ char *ptr = &remcom_in_buffer[2];
+ unsigned long addr;
+ unsigned long length;
+ int error = 0;
+
+ if (arch_kgdb_ops.set_hw_breakpoint && *bpt_type >= '1') {
+ /* Unsupported */
+ if (*bpt_type > '4')
+ return;
+ } else {
+ if (*bpt_type != '0' && *bpt_type != '1')
+ /* Unsupported. */
+ return;
+ }
+
+ /*
+ * Test if this is a hardware breakpoint, and
+ * if we support it:
+ */
+ if (*bpt_type == '1' && !(arch_kgdb_ops.flags & KGDB_HW_BREAKPOINT))
+ /* Unsupported. */
+ return;
+
+ if (*(ptr++) != ',') {
+ error_packet(remcom_out_buffer, -EINVAL);
+ return;
+ }
+ if (!kgdb_hex2long(&ptr, &addr)) {
+ error_packet(remcom_out_buffer, -EINVAL);
+ return;
+ }
+ if (*(ptr++) != ',' ||
+ !kgdb_hex2long(&ptr, &length)) {
+ error_packet(remcom_out_buffer, -EINVAL);
+ return;
+ }
+
+ if (remcom_in_buffer[0] == 'Z' && *bpt_type == '0')
+ error = kgdb_set_sw_break(addr);
+ else if (remcom_in_buffer[0] == 'z' && *bpt_type == '0')
+ error = kgdb_remove_sw_break(addr);
+ else if (remcom_in_buffer[0] == 'Z')
+ error = arch_kgdb_ops.set_hw_breakpoint(addr,
+ (int)length, *bpt_type - '0');
+ else if (remcom_in_buffer[0] == 'z')
+ error = arch_kgdb_ops.remove_hw_breakpoint(addr,
+ (int) length, *bpt_type - '0');
+
+ if (error == 0)
+ strcpy(remcom_out_buffer, "OK");
+ else
+ error_packet(remcom_out_buffer, error);
+}
+
+/* Handle the 'C' signal / exception passing packets */
+static int gdb_cmd_exception_pass(struct kgdb_state *ks)
+{
+ /* C09 == pass exception
+ * C15 == detach kgdb, pass exception
+ */
+ if (remcom_in_buffer[1] == '0' && remcom_in_buffer[2] == '9') {
+
+ ks->pass_exception = 1;
+ remcom_in_buffer[0] = 'c';
+
+ } else if (remcom_in_buffer[1] == '1' && remcom_in_buffer[2] == '5') {
+
+ ks->pass_exception = 1;
+ remcom_in_buffer[0] = 'D';
+ remove_all_break();
+ kgdb_connected = 0;
+ return 1;
+
+ } else {
+ error_packet(remcom_out_buffer, -EINVAL);
+ return 0;
+ }
+
+ /* Indicate fall through */
+ return -1;
+}
+
+/*
+ * This function performs all gdbserial command procesing
+ */
+static int gdb_serial_stub(struct kgdb_state *ks)
+{
+ int error = 0;
+ int tmp;
+
+ /* Clear the out buffer. */
+ memset(remcom_out_buffer, 0, sizeof(remcom_out_buffer));
+
+ if (kgdb_connected) {
+ unsigned char thref[8];
+ char *ptr;
+
+ /* Reply to host that an exception has occurred */
+ ptr = remcom_out_buffer;
+ *ptr++ = 'T';
+ ptr = pack_hex_byte(ptr, ks->signo);
+ ptr += strlen(strcpy(ptr, "thread:"));
+ int_to_threadref(thref, shadow_pid(current->pid));
+ ptr = pack_threadid(ptr, thref);
+ *ptr++ = ';';
+ put_packet(remcom_out_buffer);
+ }
+
+ kgdb_usethread = kgdb_info[ks->cpu].task;
+ ks->kgdb_usethreadid = shadow_pid(kgdb_info[ks->cpu].task->pid);
+ ks->pass_exception = 0;
+
+ while (1) {
+ error = 0;
+
+ /* Clear the out buffer. */
+ memset(remcom_out_buffer, 0, sizeof(remcom_out_buffer));
+
+ get_packet(remcom_in_buffer);
+
+ switch (remcom_in_buffer[0]) {
+ case '?': /* gdbserial status */
+ gdb_cmd_status(ks);
+ break;
+ case 'g': /* return the value of the CPU registers */
+ gdb_cmd_getregs(ks);
+ break;
+ case 'G': /* set the value of the CPU registers - return OK */
+ gdb_cmd_setregs(ks);
+ break;
+ case 'm': /* mAA..AA,LLLL Read LLLL bytes at address AA..AA */
+ gdb_cmd_memread(ks);
+ break;
+ case 'M': /* MAA..AA,LLLL: Write LLLL bytes at address AA..AA */
+ gdb_cmd_memwrite(ks);
+ break;
+ case 'X': /* XAA..AA,LLLL: Write LLLL bytes at address AA..AA */
+ gdb_cmd_binwrite(ks);
+ break;
+ /* kill or detach. KGDB should treat this like a
+ * continue.
+ */
+ case 'D': /* Debugger detach */
+ case 'k': /* Debugger detach via kill */
+ gdb_cmd_detachkill(ks);
+ goto default_handle;
+ case 'R': /* Reboot */
+ if (gdb_cmd_reboot(ks))
+ goto default_handle;
+ break;
+ case 'q': /* query command */
+ gdb_cmd_query(ks);
+ break;
+ case 'H': /* task related */
+ gdb_cmd_task(ks);
+ break;
+ case 'T': /* Query thread status */
+ gdb_cmd_thread(ks);
+ break;
+ case 'z': /* Break point remove */
+ case 'Z': /* Break point set */
+ gdb_cmd_break(ks);
+ break;
+ case 'C': /* Exception passing */
+ tmp = gdb_cmd_exception_pass(ks);
+ if (tmp > 0)
+ goto default_handle;
+ if (tmp == 0)
+ break;
+ /* Fall through on tmp < 0 */
+ case 'c': /* Continue packet */
+ case 's': /* Single step packet */
+ if (kgdb_contthread && kgdb_contthread != current) {
+ /* Can't switch threads in kgdb */
+ error_packet(remcom_out_buffer, -EINVAL);
+ break;
+ }
+ kgdb_activate_sw_breakpoints();
+ /* Fall through to default processing */
+ default:
+default_handle:
+ error = kgdb_arch_handle_exception(ks->ex_vector,
+ ks->signo,
+ ks->err_code,
+ remcom_in_buffer,
+ remcom_out_buffer,
+ ks->linux_regs);
+ /*
+ * Leave cmd processing on error, detach,
+ * kill, continue, or single step.
+ */
+ if (error >= 0 || remcom_in_buffer[0] == 'D' ||
+ remcom_in_buffer[0] == 'k') {
+ error = 0;
+ goto kgdb_exit;
+ }
+
+ }
+
+ /* reply to the request */
+ put_packet(remcom_out_buffer);
+ }
+
+kgdb_exit:
+ if (ks->pass_exception)
+ error = 1;
+ return error;
+}
+
+static int kgdb_reenter_check(struct kgdb_state *ks)
+{
+ unsigned long addr;
+
+ if (atomic_read(&kgdb_active) != raw_smp_processor_id())
+ return 0;
+
+ /* Panic on recursive debugger calls: */
+ exception_level++;
+ addr = kgdb_arch_pc(ks->ex_vector, ks->linux_regs);
+ kgdb_deactivate_sw_breakpoints();
+
+ /*
+ * If the break point removed ok at the place exception
+ * occurred, try to recover and print a warning to the end
+ * user because the user planted a breakpoint in a place that
+ * KGDB needs in order to function.
+ */
+ if (kgdb_remove_sw_break(addr) == 0) {
+ exception_level = 0;
+ kgdb_skipexception(ks->ex_vector, ks->linux_regs);
+ kgdb_activate_sw_breakpoints();
+ printk(KERN_CRIT "KGDB: re-enter error: breakpoint removed %lx\n",
+ addr);
+ WARN_ON_ONCE(1);
+
+ return 1;
+ }
+ remove_all_break();
+ kgdb_skipexception(ks->ex_vector, ks->linux_regs);
+
+ if (exception_level > 1) {
+ dump_stack();
+ panic("Recursive entry to debugger");
+ }
+
+ printk(KERN_CRIT "KGDB: re-enter exception: ALL breakpoints killed\n");
+ dump_stack();
+ panic("Recursive entry to debugger");
+
+ return 1;
+}
+
+/*
+ * kgdb_handle_exception() - main entry point from a kernel exception
+ *
+ * Locking hierarchy:
+ * interface locks, if any (begin_session)
+ * kgdb lock (kgdb_active)
+ */
+int
+kgdb_handle_exception(int evector, int signo, int ecode, struct pt_regs *regs)
+{
+ struct kgdb_state kgdb_var;
+ struct kgdb_state *ks = &kgdb_var;
+ unsigned long flags;
+ int error = 0;
+ int i, cpu;
+
+ ks->cpu = raw_smp_processor_id();
+ ks->ex_vector = evector;
+ ks->signo = signo;
+ ks->ex_vector = evector;
+ ks->err_code = ecode;
+ ks->kgdb_usethreadid = 0;
+ ks->linux_regs = regs;
+
+ if (kgdb_reenter_check(ks))
+ return 0; /* Ouch, double exception ! */
+
+acquirelock:
+ /*
+ * Interrupts will be restored by the 'trap return' code, except when
+ * single stepping.
+ */
+ local_irq_save(flags);
+
+ cpu = raw_smp_processor_id();
+
+ /*
+ * Acquire the kgdb_active lock:
+ */
+ while (atomic_cmpxchg(&kgdb_active, -1, cpu) != -1)
+ cpu_relax();
+
+ /*
+ * Do not start the debugger connection on this CPU if the last
+ * instance of the exception handler wanted to come into the
+ * debugger on a different CPU via a single step
+ */
+ if (atomic_read(&kgdb_cpu_doing_single_step) != -1 &&
+ atomic_read(&kgdb_cpu_doing_single_step) != cpu) {
+
+ atomic_set(&kgdb_active, -1);
+ clocksource_touch_watchdog();
+ local_irq_restore(flags);
+
+ goto acquirelock;
+ }
+
+ if (!kgdb_io_ready(1)) {
+ error = 1;
+ goto kgdb_restore; /* No I/O connection, so resume the system */
+ }
+
+ /*
+ * Don't enter if we have hit a removed breakpoint.
+ */
+ if (kgdb_skipexception(ks->ex_vector, ks->linux_regs))
+ goto kgdb_restore;
+
+ /* Call the I/O driver's pre_exception routine */
+ if (kgdb_io_ops->pre_exception)
+ kgdb_io_ops->pre_exception();
+
+ kgdb_info[ks->cpu].debuggerinfo = ks->linux_regs;
+ kgdb_info[ks->cpu].task = current;
+
+ kgdb_disable_hw_debug(ks->linux_regs);
+
+ /*
+ * Get the passive CPU lock which will hold all the non-primary
+ * CPU in a spin state while the debugger is active
+ */
+ if (!kgdb_single_step || !kgdb_contthread) {
+ for (i = 0; i < NR_CPUS; i++)
+ atomic_set(&passive_cpu_wait[i], 1);
+ }
+
+#ifdef CONFIG_SMP
+ /* Signal the other CPUs to enter kgdb_wait() */
+ if (!kgdb_single_step || !kgdb_contthread)
+ kgdb_roundup_cpus(flags);
+#endif
+
+ /*
+ * spin_lock code is good enough as a barrier so we don't
+ * need one here:
+ */
+ atomic_set(&cpu_in_kgdb[ks->cpu], 1);
+
+ /*
+ * Wait for the other CPUs to be notified and be waiting for us:
+ */
+ for_each_online_cpu(i) {
+ while (!atomic_read(&cpu_in_kgdb[i]))
+ cpu_relax();
+ }
+
+ /*
+ * At this point the primary processor is completely
+ * in the debugger and all secondary CPUs are quiescent
+ */
+ kgdb_post_primary_code(ks->linux_regs, ks->ex_vector, ks->err_code);
+ kgdb_deactivate_sw_breakpoints();
+ kgdb_single_step = 0;
+ kgdb_contthread = NULL;
+ exception_level = 0;
+
+ /* Talk to debugger with gdbserial protocol */
+ error = gdb_serial_stub(ks);
+
+ /* Call the I/O driver's post_exception routine */
+ if (kgdb_io_ops->post_exception)
+ kgdb_io_ops->post_exception();
+
+ kgdb_info[ks->cpu].debuggerinfo = NULL;
+ kgdb_info[ks->cpu].task = NULL;
+ atomic_set(&cpu_in_kgdb[ks->cpu], 0);
+
+ if (!kgdb_single_step || !kgdb_contthread) {
+ for (i = NR_CPUS-1; i >= 0; i--)
+ atomic_set(&passive_cpu_wait[i], 0);
+ /*
+ * Wait till all the CPUs have quit
+ * from the debugger.
+ */
+ for_each_online_cpu(i) {
+ while (atomic_read(&cpu_in_kgdb[i]))
+ cpu_relax();
+ }
+ }
+
+kgdb_restore:
+ /* Free kgdb_active */
+ atomic_set(&kgdb_active, -1);
+ clocksource_touch_watchdog();
+ local_irq_restore(flags);
+
+ return error;
+}
+
+int kgdb_nmicallback(int cpu, void *regs)
+{
+#ifdef CONFIG_SMP
+ if (!atomic_read(&cpu_in_kgdb[cpu]) &&
+ atomic_read(&kgdb_active) != cpu) {
+ kgdb_wait((struct pt_regs *)regs);
+ return 0;
+ }
+#endif
+ return 1;
+}
+
+void kgdb_console_write(struct console *co, const char *s, unsigned count)
+{
+ unsigned long flags;
+
+ /* If we're debugging, or KGDB has not connected, don't try
+ * and print. */
+ if (!kgdb_connected || atomic_read(&kgdb_active) != -1)
+ return;
+
+ local_irq_save(flags);
+ kgdb_msg_write(s, count);
+ local_irq_restore(flags);
+}
+
+static struct console kgdbcons = {
+ .name = "kgdb",
+ .write = kgdb_console_write,
+ .flags = CON_PRINTBUFFER | CON_ENABLED,
+ .index = -1,
+};
+
+#ifdef CONFIG_MAGIC_SYSRQ
+static void sysrq_handle_gdb(int key, struct tty_struct *tty)
+{
+ if (!kgdb_io_ops) {
+ printk(KERN_CRIT "ERROR: No KGDB I/O module available\n");
+ return;
+ }
+ if (!kgdb_connected)
+ printk(KERN_CRIT "Entering KGDB\n");
+
+ kgdb_breakpoint();
+}
+
+static struct sysrq_key_op sysrq_gdb_op = {
+ .handler = sysrq_handle_gdb,
+ .help_msg = "Gdb",
+ .action_msg = "GDB",
+};
+#endif
+
+static void kgdb_register_callbacks(void)
+{
+ if (!kgdb_io_module_registered) {
+ kgdb_io_module_registered = 1;
+ kgdb_arch_init();
+#ifdef CONFIG_MAGIC_SYSRQ
+ register_sysrq_key('g', &sysrq_gdb_op);
+#endif
+ if (kgdb_use_con && !kgdb_con_registered) {
+ register_console(&kgdbcons);
+ kgdb_con_registered = 1;
+ }
+ }
+}
+
+static void kgdb_unregister_callbacks(void)
+{
+ /*
+ * When this routine is called KGDB should unregister from the
+ * panic handler and clean up, making sure it is not handling any
+ * break exceptions at the time.
+ */
+ if (kgdb_io_module_registered) {
+ kgdb_io_module_registered = 0;
+ kgdb_arch_exit();
+#ifdef CONFIG_MAGIC_SYSRQ
+ unregister_sysrq_key('g', &sysrq_gdb_op);
+#endif
+ if (kgdb_con_registered) {
+ unregister_console(&kgdbcons);
+ kgdb_con_registered = 0;
+ }
+ }
+}
+
+static void kgdb_initial_breakpoint(void)
+{
+ kgdb_break_asap = 0;
+
+ printk(KERN_CRIT "kgdb: Waiting for connection from remote gdb...\n");
+ kgdb_breakpoint();
+}
+
+/**
+ * kkgdb_register_io_module - register KGDB IO module
+ * @new_kgdb_io_ops: the io ops vector
+ *
+ * Register it with the KGDB core.
+ */
+int kgdb_register_io_module(struct kgdb_io *new_kgdb_io_ops)
+{
+ int err;
+
+ spin_lock(&kgdb_registration_lock);
+
+ if (kgdb_io_ops) {
+ spin_unlock(&kgdb_registration_lock);
+
+ printk(KERN_ERR "kgdb: Another I/O driver is already "
+ "registered with KGDB.\n");
+ return -EBUSY;
+ }
+
+ if (new_kgdb_io_ops->init) {
+ err = new_kgdb_io_ops->init();
+ if (err) {
+ spin_unlock(&kgdb_registration_lock);
+ return err;
+ }
+ }
+
+ kgdb_io_ops = new_kgdb_io_ops;
+
+ spin_unlock(&kgdb_registration_lock);
+
+ printk(KERN_INFO "kgdb: Registered I/O driver %s.\n",
+ new_kgdb_io_ops->name);
+
+ /* Arm KGDB now. */
+ kgdb_register_callbacks();
+
+ if (kgdb_break_asap)
+ kgdb_initial_breakpoint();
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(kgdb_register_io_module);
+
+/**
+ * kkgdb_unregister_io_module - unregister KGDB IO module
+ * @old_kgdb_io_ops: the io ops vector
+ *
+ * Unregister it with the KGDB core.
+ */
+void kgdb_unregister_io_module(struct kgdb_io *old_kgdb_io_ops)
+{
+ BUG_ON(kgdb_connected);
+
+ /*
+ * KGDB is no longer able to communicate out, so
+ * unregister our callbacks and reset state.
+ */
+ kgdb_unregister_callbacks();
+
+ spin_lock(&kgdb_registration_lock);
+
+ WARN_ON_ONCE(kgdb_io_ops != old_kgdb_io_ops);
+ kgdb_io_ops = NULL;
+
+ spin_unlock(&kgdb_registration_lock);
+
+ printk(KERN_INFO
+ "kgdb: Unregistered I/O driver %s, debugger disabled.\n",
+ old_kgdb_io_ops->name);
+}
+EXPORT_SYMBOL_GPL(kgdb_unregister_io_module);
+
+/**
+ * kgdb_breakpoint - generate breakpoint exception
+ *
+ * This function will generate a breakpoint exception. It is used at the
+ * beginning of a program to sync up with a debugger and can be used
+ * otherwise as a quick means to stop program execution and "break" into
+ * the debugger.
+ */
+void kgdb_breakpoint(void)
+{
+ atomic_set(&kgdb_setting_breakpoint, 1);
+ wmb(); /* Sync point before breakpoint */
+ arch_kgdb_breakpoint();
+ wmb(); /* Sync point after breakpoint */
+ atomic_set(&kgdb_setting_breakpoint, 0);
+}
+EXPORT_SYMBOL_GPL(kgdb_breakpoint);
+
+static int __init opt_kgdb_wait(char *str)
+{
+ kgdb_break_asap = 1;
+
+ if (kgdb_io_module_registered)
+ kgdb_initial_breakpoint();
+
+ return 0;
+}
+
+early_param("kgdbwait", opt_kgdb_wait);
--
1.5.4
^ permalink raw reply related [flat|nested] 8+ messages in thread