x86_64-lite.patch

Linux-2.6.18内核调试工具补丁程序KGDB。

+	gdb_x86_64vector = e_vector;
+	gdb_x86_64errcode = err_code;
+}
+
+void kgdb_roundup_cpus(unsigned long flags)
+{
+	send_IPI_allbutself(APIC_DM_NMI);
+}
+
+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, length;
+	unsigned long breakno, breaktype;
+	char *ptr;
+	int newPC;
+	unsigned long dr6;
+
+	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->rip = addr;
+		newPC = linux_regs->rip;
+
+		/* clear the trace bit */
+		linux_regs->eflags &= ~TF_MASK;
+
+		atomic_set(&cpu_doing_single_step, -1);
+		/* set the trace bit if we're stepping */
+		if (remcomInBuffer[0] == 's') {
+			linux_regs->eflags |= TF_MASK;
+			debugger_step = 1;
+			if (kgdb_contthread)
+				atomic_set(&cpu_doing_single_step,
+					   smp_processor_id());
+
+		}
+
+		asm volatile ("movq %%db6, %0\n":"=r" (dr6));
+		if (!(dr6 & 0x4000)) {
+			for (breakno = 0; breakno < 4; ++breakno) {
+				if (dr6 & (1 << breakno)) {
+					if (breakinfo[breakno].type == 0) {
+						/* Set restore flag */
+						linux_regs->eflags |=
+						    X86_EFLAGS_RF;
+						break;
+					}
+				}
+			}
+		}
+		kgdb_correct_hw_break();
+		asm volatile ("movq %0, %%db6\n"::"r" (0UL));
+
+		return (0);
+
+	case 'Y':
+		ptr = &remcomInBuffer[1];
+		kgdb_hex2long(&ptr, &breakno);
+		ptr++;
+		kgdb_hex2long(&ptr, &breaktype);
+		ptr++;
+		kgdb_hex2long(&ptr, &length);
+		ptr++;
+		kgdb_hex2long(&ptr, &addr);
+		if (set_hw_break(breakno & 0x3, breaktype & 0x3,
+				 length & 0x3, addr) == 0)
+			strcpy(remcomOutBuffer, "OK");
+		else
+			strcpy(remcomOutBuffer, "ERROR");
+		break;
+
+		/* Remove hardware breakpoint */
+	case 'y':
+		ptr = &remcomInBuffer[1];
+		kgdb_hex2long(&ptr, &breakno);
+		if (remove_hw_break(breakno & 0x3) == 0)
+			strcpy(remcomOutBuffer, "OK");
+		else
+			strcpy(remcomOutBuffer, "ERROR");
+		break;
+
+	}			/* switch */
+	return -1;
+}
+
+static struct pt_regs *in_interrupt_stack(unsigned long rsp, int cpu)
+{
+	struct pt_regs *regs;
+	unsigned long end = (unsigned long)cpu_pda(cpu)->irqstackptr;
+	if (rsp <= end && rsp >= end - IRQSTACKSIZE + 8) {
+		regs = *(((struct pt_regs **)end) - 1);
+		return regs;
+	}
+	return NULL;
+}
+
+static struct pt_regs *in_exception_stack(unsigned long rsp, int cpu)
+{
+	int i;
+	struct tss_struct *init_tss = &__get_cpu_var(init_tss);
+	for (i = 0; i < N_EXCEPTION_STACKS; i++)
+		if (rsp >= init_tss[cpu].ist[i] &&
+		    rsp <= init_tss[cpu].ist[i] + EXCEPTION_STKSZ) {
+			struct pt_regs *r =
+			    (void *)init_tss[cpu].ist[i] + EXCEPTION_STKSZ;
+			return r - 1;
+		}
+	return NULL;
+}
+
+void kgdb_shadowinfo(struct pt_regs *regs, char *buffer, unsigned threadid)
+{
+	static char intr_desc[] = "Stack at interrupt entrypoint";
+	static char exc_desc[] = "Stack at exception entrypoint";
+	struct pt_regs *stregs;
+	int cpu = hard_smp_processor_id();
+
+	if ((stregs = in_interrupt_stack(regs->rsp, cpu)))
+		kgdb_mem2hex(intr_desc, buffer, strlen(intr_desc));
+	else if ((stregs = in_exception_stack(regs->rsp, cpu)))
+		kgdb_mem2hex(exc_desc, buffer, strlen(exc_desc));
+}
+
+struct task_struct *kgdb_get_shadow_thread(struct pt_regs *regs, int threadid)
+{
+	struct pt_regs *stregs;
+	int cpu = hard_smp_processor_id();
+
+	if ((stregs = in_interrupt_stack(regs->rsp, cpu)))
+		return current;
+	else if ((stregs = in_exception_stack(regs->rsp, cpu)))
+		return current;
+
+	return NULL;
+}
+
+struct pt_regs *kgdb_shadow_regs(struct pt_regs *regs, int threadid)
+{
+	struct pt_regs *stregs;
+	int cpu = hard_smp_processor_id();
+
+	if ((stregs = in_interrupt_stack(regs->rsp, cpu)))
+		return stregs;
+	else if ((stregs = in_exception_stack(regs->rsp, cpu)))
+		return stregs;
+
+	return NULL;
+}
+
+/* Register KGDB with the die_chain so that we hook into all of the right
+ * spots. */
+static int kgdb_notify(struct notifier_block *self, unsigned long cmd,
+		       void *ptr)
+{
+	struct die_args *args = ptr;
+	struct pt_regs *regs = args->regs;
+
+	if (cmd == DIE_PAGE_FAULT_NO_CONTEXT && atomic_read(&debugger_active)
+			&& kgdb_may_fault) {
+		kgdb_fault_longjmp(kgdb_fault_jmp_regs);
+		return NOTIFY_STOP;
+	/* CPU roundup? */
+	} else if (atomic_read(&debugger_active) && cmd == DIE_NMI_IPI) {
+		kgdb_nmihook(smp_processor_id(), regs);
+		return NOTIFY_STOP;
+		/* See if KGDB is interested. */
+	} else if (cmd == DIE_PAGE_FAULT || user_mode(regs) ||
+		   cmd == DIE_NMI_IPI || (cmd == DIE_DEBUG &&
+					  atomic_read(&debugger_active)))
+		/* Userpace events, normal watchdog event, or spurious
+		 * debug exception.  Ignore. */
+		return NOTIFY_DONE;
+
+	kgdb_handle_exception(args->trapnr, args->signr, args->err, regs);
+
+	return NOTIFY_STOP;
+}
+
+static struct notifier_block kgdb_notifier = {
+	.notifier_call = kgdb_notify,
+	.priority = 0x7fffffff,	/* we need to notified first */
+};
+
+int kgdb_arch_init(void)
+{
+	notifier_chain_register(&die_chain, &kgdb_notifier);
+	return 0;
+}
+/*
+ * 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->rip - 1)) {
+		regs->rip -= 1;
+		return 1;
+	}
+	return 0;
+}
+
+struct kgdb_arch arch_kgdb_ops = {
+	.gdb_bpt_instr = {0xcc},
+	.flags = KGDB_HW_BREAKPOINT,
+	.shadowth = 1,
+};
Index: linux-2.6.15-rc6-x86_64/arch/x86_64/kernel/Makefile
===================================================================
--- linux-2.6.15-rc6-x86_64.orig/arch/x86_64/kernel/Makefile	2005-12-21 10:09:55.000000000 +0530
+++ linux-2.6.15-rc6-x86_64/arch/x86_64/kernel/Makefile	2005-12-26 14:01:58.321765336 +0530
@@ -29,6 +29,7 @@
 obj-$(CONFIG_GART_IOMMU)	+= pci-gart.o aperture.o
 obj-$(CONFIG_DUMMY_IOMMU)	+= pci-nommu.o pci-dma.o
 obj-$(CONFIG_KPROBES)		+= kprobes.o
+obj-$(CONFIG_KGDB)		+= kgdb.o kgdb-jmp.o
 obj-$(CONFIG_X86_PM_TIMER)	+= pmtimer.o
 
 obj-$(CONFIG_MODULES)		+= module.o
Index: linux-2.6.15-rc6-x86_64/lib/Kconfig.debug
===================================================================
--- linux-2.6.15-rc6-x86_64.orig/lib/Kconfig.debug	2005-12-26 14:01:53.913435504 +0530
+++ linux-2.6.15-rc6-x86_64/lib/Kconfig.debug	2005-12-26 14:01:58.334763360 +0530
@@ -209,7 +209,7 @@
 config KGDB
 	bool "KGDB: kernel debugging with remote gdb"
 	select WANT_EXTRA_DEBUG_INFORMATION
-	depends on DEBUG_KERNEL && (X86 || MIPS || IA64 || PPC)
+	depends on DEBUG_KERNEL && (X86 || MIPS || IA64 || X86_64 || PPC)
 	help
 	  If you say Y here, it will be possible to remotely debug the
 	  kernel using gdb. It is strongly suggested that you enable
Index: linux-2.6.15-rc6-x86_64/kernel/kgdb.c
===================================================================
--- linux-2.6.15-rc6-x86_64.orig/kernel/kgdb.c	2005-12-26 13:59:37.552165568 +0530
+++ linux-2.6.15-rc6-x86_64/kernel/kgdb.c	2005-12-26 14:01:58.335763208 +0530
@@ -1718,7 +1718,8 @@
  */
 static void kgdb_tasklet_bpt(unsigned long ing)
 {
-	breakpoint();
+	if(CHECK_EXCEPTION_STACK())
+		breakpoint();
 }
 
 DECLARE_TASKLET(kgdb_tasklet_breakpoint, kgdb_tasklet_bpt, 0);
@@ -1729,6 +1730,17 @@
  */
 static void __init kgdb_early_entry(void)
 {
+	/*
+	 * Don't try and do anything until the architecture is able to
+	 * setup the exception stack.  In this case, it is up to the
+	 * architecture to hook in and look at us when they are ready.
+	 */
+	if(!CHECK_EXCEPTION_STACK()) {
+		kgdb_initialized = -1;
+		tasklet_schedule(&kgdb_tasklet_breakpoint);
+		return;
+	}
+
 	/* Let the architecture do any setup that it needs to. */
 	kgdb_arch_init();
 
Index: linux-2.6.15-rc6-x86_64/include/asm-x86_64/kgdb.h
===================================================================
--- linux-2.6.15-rc6-x86_64.orig/include/asm-x86_64/kgdb.h	2005-12-26 12:14:53.973528792 +0530
+++ linux-2.6.15-rc6-x86_64/include/asm-x86_64/kgdb.h	2005-12-26 14:01:58.321765336 +0530
@@ -0,0 +1,50 @@
+#ifdef __KERNEL__
+#ifndef _ASM_KGDB_H_
+#define _ASM_KGDB_H_
+
+/*
+ * Copyright (C) 2001-2004 Amit S. Kale
+ */
+
+/*
+ *  Note that this register image is in a different order than
+ *  the register image that Linux produces at interrupt time.
+ *
+ *  Linux's register image is defined by struct pt_regs in ptrace.h.
+ *  Just why GDB uses a different order is a historical mystery.
+ */
+#define _RAX	0
+#define _RDX	1
+#define _RCX	2
+#define _RBX	3
+#define _RSI	4
+#define _RDI	5
+#define _RBP	6
+#define _RSP	7
+#define _R8	8
+#define _R9	9
+#define _R10	10
+#define _R11	11
+#define _R12	12
+#define _R13	13
+#define _R14	14
+#define _R15	15
+#define _PC	16
+#define _PS	17
+
+/* Number of bytes of registers.  */
+#define NUMREGBYTES		((_PS+1)*8)
+#define NUMCRITREGBYTES		(8 * 8)		/* 8 registers. */
+
+#ifndef __ASSEMBLY__
+/* BUFMAX defines the maximum number of characters in inbound/outbound
+ * buffers at least NUMREGBYTES*2 are needed for register packets, and
+ * a longer buffer is needed to list all threads. */
+#define BUFMAX			1024
+#define BREAKPOINT()		asm("   int $3");
+#define CHECK_EXCEPTION_STACK() ((&__get_cpu_var(init_tss))[0].ist[0])
+#define BREAK_INSTR_SIZE	1
+#define CACHE_FLUSH_IS_SAFE	1
+#endif				/* !__ASSEMBLY__ */
+#endif				/* _ASM_KGDB_H_ */
+#endif				/* __KERNEL__ */
Index: linux-2.6.15-rc6-x86_64/include/asm-x86_64/system.h
===================================================================
--- linux-2.6.15-rc6-x86_64.orig/include/asm-x86_64/system.h	2005-10-28 05:32:08.000000000 +0530
+++ linux-2.6.15-rc6-x86_64/include/asm-x86_64/system.h	2005-12-26 14:01:58.333763512 +0530
@@ -27,7 +27,9 @@
 	,"rcx","rbx","rdx","r8","r9","r10","r11","r12","r13","r14","r15"
 
 #define switch_to(prev,next,last) \
-	asm volatile(SAVE_CONTEXT						    \
+       asm volatile(".globl __switch_to_begin\n\t"				    \
+		     "__switch_to_begin:\n\t"					  \
+		     SAVE_CONTEXT						  \
 		     "movq %%rsp,%P[threadrsp](%[prev])\n\t" /* save RSP */	  \
 		     "movq %P[threadrsp](%[next]),%%rsp\n\t" /* restore RSP */	  \
 		     "call __switch_to\n\t"					  \
@@ -39,6 +41,8 @@
 		     "movq %%rax,%%rdi\n\t" 					  \
 		     "jc   ret_from_fork\n\t"					  \
 		     RESTORE_CONTEXT						    \
+		     ".globl __switch_to_end\n\t"				  \
+		     "__switch_to_end:\n\t"					  \
 		     : "=a" (last)					  	  \
 		     : [next] "S" (next), [prev] "D" (prev),			  \
 		       [threadrsp] "i" (offsetof(struct task_struct, thread.rsp)), \
Index: linux-2.6.15-rc6-x86_64/include/linux/kgdb.h
===================================================================
--- linux-2.6.15-rc6-x86_64.orig/include/linux/kgdb.h	2005-12-26 13:59:37.472177728 +0530
+++ linux-2.6.15-rc6-x86_64/include/linux/kgdb.h	2005-12-26 14:01:58.334763360 +0530
@@ -24,6 +24,10 @@
 #include <linux/linkage.h>
 #include <linux/init.h>
 
+#ifndef CHECK_EXCEPTION_STACK
+#define CHECK_EXCEPTION_STACK()	1
+#endif
+
 struct tasklet_struct;
 struct pt_regs;
 struct task_struct;