i386-lite.patch

Linux-2.6.18内核调试工具补丁程序KGDB。

+}
+
+void kgdb_disable_hw_debug(struct pt_regs *regs)
+{
+	/* Disable hardware debugging while we are in kgdb */
+	asm volatile ("movl %0,%%db7": /* no output */ :"r" (0));
+}
+
+void kgdb_post_master_code(struct pt_regs *regs, int e_vector, int err_code)
+{
+	/* Master processor is completely in the debugger */
+	gdb_i386vector = e_vector;
+	gdb_i386errcode = 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 *remcom_in_buffer,
+			       char *remcom_out_buffer,
+			       struct pt_regs *linux_regs)
+{
+	long addr;
+	char *ptr;
+	int newPC, dr6;
+
+	switch (remcom_in_buffer[0]) {
+	case 'c':
+	case 's':
+		/* try to read optional parameter, pc unchanged if no parm */
+		ptr = &remcom_in_buffer[1];
+		if (kgdb_hex2long(&ptr, &addr))
+			linux_regs->eip = addr;
+		newPC = linux_regs->eip;
+
+		/* 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 (remcom_in_buffer[0] == 's') {
+			linux_regs->eflags |= TF_MASK;
+			debugger_step = 1;
+			atomic_set(&cpu_doing_single_step,smp_processor_id());
+		}
+
+		asm volatile ("movl %%db6, %0\n":"=r" (dr6));
+		if (!(dr6 & 0x4000)) {
+			long breakno;
+			for (breakno = 0; breakno < 4; ++breakno) {
+				if (dr6 & (1 << breakno) &&
+				    breakinfo[breakno].type == 0) {
+					/* Set restore flag */
+					linux_regs->eflags |= X86_EFLAGS_RF;
+					break;
+				}
+			}
+		}
+		kgdb_correct_hw_break();
+		asm volatile ("movl %0, %%db6\n"::"r" (0));
+
+		return (0);
+	}			/* switch */
+	/* this means that we do not want to exit from the handler */
+	return -1;
+}
+
+/* Register KGDB with the i386die_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;
+
+	/* Bad memory access? */
+	if (cmd == DIE_PAGE_FAULT_NO_CONTEXT && atomic_read(&debugger_active)
+			&& kgdb_may_fault) {
+		kgdb_fault_longjmp(kgdb_fault_jmp_regs);
+		return NOTIFY_STOP;
+	} else if (cmd == DIE_PAGE_FAULT)
+		/* A normal page fault, ignore. */
+		return NOTIFY_DONE;
+       else if ((cmd == DIE_NMI || cmd == DIE_NMI_IPI ||
+               cmd == DIE_NMIWATCHDOG) && atomic_read(&debugger_active)) {
+               /* CPU roundup */
+               kgdb_nmihook(smp_processor_id(), regs);
+               return NOTIFY_STOP;
+       } else if (cmd == DIE_NMI_IPI || cmd == DIE_NMI || user_mode(regs) ||
+                       (cmd == DIE_DEBUG && atomic_read(&debugger_active)))
+               /* Normal watchdog event or userspace debugging, 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,
+};
+
+int kgdb_arch_init(void)
+{
+	notifier_chain_register(&i386die_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->eip - 1)) {
+		regs->eip -= 1;
+		return 1;
+	}
+	return 0;
+}
+
+struct kgdb_arch arch_kgdb_ops = {
+	.gdb_bpt_instr = {0xcc},
+};
Index: linux-2.6.16/arch/i386/kernel/traps.c
===================================================================
--- linux-2.6.16.orig/arch/i386/kernel/traps.c	2006-03-20 11:23:29.000000000 +0530
+++ linux-2.6.16/arch/i386/kernel/traps.c	2006-04-25 11:30:14.000000000 +0530
@@ -365,7 +365,7 @@
 #endif
 		if (nl)
 			printk("\n");
-	notify_die(DIE_OOPS, (char *)str, regs, err, 255, SIGSEGV);
+		notify_die(DIE_OOPS, (char *)str, regs, err, 255, SIGSEGV);
 		show_registers(regs);
   	} else
 		printk(KERN_EMERG "Recursive die() failure, output suppressed\n");
@@ -787,6 +787,7 @@
 	 */
 clear_dr7:
 	set_debugreg(0, 7);
+	notify_die(DIE_DEBUG, "debug2", regs, condition, error_code, SIGTRAP);
 	return;
 
 debug_vm86:
@@ -1091,6 +1092,12 @@
 	_set_gate(idt_table+n,5,0,0,(gdt_entry<<3));
 }
 
+/* Some traps need to be set early. */
+void __init early_trap_init(void) {
+	set_intr_gate(1,&debug);
+	set_system_intr_gate(3, &int3); /* int3 can be called from all */
+	set_intr_gate(14,&page_fault);
+}
 
 void __init trap_init(void)
 {
@@ -1107,10 +1114,8 @@
 #endif
 
 	set_trap_gate(0,&divide_error);
-	set_intr_gate(1,&debug);
 	set_intr_gate(2,&nmi);
-	set_system_intr_gate(3, &int3); /* int3/4 can be called from all */
-	set_system_gate(4,&overflow);
+	set_system_gate(4,&overflow); /* int4/5 can be called from all */
 	set_trap_gate(5,&bounds);
 	set_trap_gate(6,&invalid_op);
 	set_trap_gate(7,&device_not_available);
@@ -1120,7 +1125,6 @@
 	set_trap_gate(11,&segment_not_present);
 	set_trap_gate(12,&stack_segment);
 	set_trap_gate(13,&general_protection);
-	set_intr_gate(14,&page_fault);
 	set_trap_gate(15,&spurious_interrupt_bug);
 	set_trap_gate(16,&coprocessor_error);
 	set_trap_gate(17,&alignment_check);
Index: linux-2.6.16/arch/i386/kernel/Makefile
===================================================================
--- linux-2.6.16.orig/arch/i386/kernel/Makefile	2006-03-20 11:23:29.000000000 +0530
+++ linux-2.6.16/arch/i386/kernel/Makefile	2006-04-25 11:28:55.000000000 +0530
@@ -37,6 +37,7 @@
 obj-$(CONFIG_DOUBLEFAULT) 	+= doublefault.o
 obj-$(CONFIG_VM86)		+= vm86.o
 obj-$(CONFIG_EARLY_PRINTK)	+= early_printk.o
+obj-$(CONFIG_KGDB)		+= kgdb.o kgdb-jmp.o
 
 EXTRA_AFLAGS   := -traditional
 
Index: linux-2.6.16/arch/i386/kernel/setup.c
===================================================================
--- linux-2.6.16.orig/arch/i386/kernel/setup.c	2006-03-20 11:23:29.000000000 +0530
+++ linux-2.6.16/arch/i386/kernel/setup.c	2006-04-25 11:30:39.000000000 +0530
@@ -147,6 +147,7 @@
 struct e820map e820;
 
 extern void early_cpu_init(void);
+extern void early_trap_init(void);
 extern void generic_apic_probe(char *);
 extern int root_mountflags;
 
@@ -1497,6 +1498,7 @@
 	memcpy(&boot_cpu_data, &new_cpu_data, sizeof(new_cpu_data));
 	pre_setup_arch_hook();
 	early_cpu_init();
+	early_trap_init();
 
 	/*
 	 * FIXME: This isn't an official loader_type right
@@ -1553,6 +1555,7 @@
 	data_resource.end = virt_to_phys(_edata)-1;
 
 	parse_cmdline_early(cmdline_p);
+	parse_early_param();
 
 	max_low_pfn = setup_memory();
 
Index: linux-2.6.16/lib/Kconfig.debug
===================================================================
--- linux-2.6.16.orig/lib/Kconfig.debug	2006-04-25 11:28:52.000000000 +0530
+++ linux-2.6.16/lib/Kconfig.debug	2006-04-25 11:28:55.000000000 +0530
@@ -232,7 +232,7 @@
 config KGDB
 	bool "KGDB: kernel debugging with remote gdb"
 	select WANT_EXTRA_DEBUG_INFORMATION
-	depends on DEBUG_KERNEL
+	depends on DEBUG_KERNEL && (X86)
 	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-2.6.16/include/asm-i386/kgdb.h
===================================================================
--- linux-2.6.16.orig/include/asm-i386/kgdb.h	2006-04-25 10:59:23.506518750 +0530
+++ linux-2.6.16/include/asm-i386/kgdb.h	2006-04-25 11:28:55.000000000 +0530
@@ -0,0 +1,49 @@
+#ifdef __KERNEL__
+#ifndef _ASM_KGDB_H_
+#define _ASM_KGDB_H_
+
+/*
+ * Copyright (C) 2001-2004 Amit S. Kale
+ */
+
+/************************************************************************/
+/* BUFMAX defines the maximum number of characters in inbound/outbound buffers*/
+/* at least NUMREGBYTES*2 are needed for register packets */
+/* Longer buffer is needed to list all threads */
+#define BUFMAX			1024
+
+/* Number of bytes of registers.  */
+#define NUMREGBYTES		64
+/* Number of bytes of registers we need to save for a setjmp/longjmp. */
+#define NUMCRITREGBYTES		24
+
+/*
+ *  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.
+ */
+enum regnames { _EAX,		/* 0 */
+	_ECX,			/* 1 */
+	_EDX,			/* 2 */
+	_EBX,			/* 3 */
+	_ESP,			/* 4 */
+	_EBP,			/* 5 */
+	_ESI,			/* 6 */
+	_EDI,			/* 7 */
+	_PC,			/* 8 also known as eip */
+	_PS,			/* 9 also known as eflags */
+	_CS,			/* 10 */
+	_SS,			/* 11 */
+	_DS,			/* 12 */
+	_ES,			/* 13 */
+	_FS,			/* 14 */
+	_GS			/* 15 */
+};
+
+#define BREAKPOINT()		asm("   int $3");
+#define BREAK_INSTR_SIZE	1
+#define CACHE_FLUSH_IS_SAFE	1
+#endif				/* _ASM_KGDB_H_ */
+#endif				/* __KERNEL__ */
Index: linux-2.6.16/include/asm-i386/kdebug.h
===================================================================
--- linux-2.6.16.orig/include/asm-i386/kdebug.h	2006-03-20 11:23:29.000000000 +0530
+++ linux-2.6.16/include/asm-i386/kdebug.h	2006-04-25 11:28:55.000000000 +0530
@@ -39,6 +39,7 @@
 	DIE_CALL,
 	DIE_NMI_IPI,
 	DIE_PAGE_FAULT,
+	DIE_PAGE_FAULT_NO_CONTEXT,
 };
 
 static inline int notify_die(enum die_val val, const char *str,