A different KGDB stub

442 lines not on this page · raw message

@@ -36,6 +36,7 @@
 #include <linux/kallsyms.h>
 #include <linux/notifier.h>
 #include <linux/cpu.h>
+#include <linux/kgdb.h>
 
 #include <asm/atomic.h>
 #include <asm/io.h>

@@ -412,7 +413,7 @@
  * SMP cross-CPU interrupts have their own specific
  * handlers).
  */
-asmlinkage unsigned int do_IRQ(struct pt_regs regs)
+asmlinkage unsigned int do_IRQ(struct pt_regs *regs)
 {	
 	/* 
 	 * We ack quickly, we don't want the irq controller

@@ -424,7 +425,7 @@
 	 * 0 return value means that this irq is already being
 	 * handled by some other CPU. (or is disabled)
 	 */
-	int irq = regs.orig_eax & 0xff; /* high bits used in ret_from_ code  */
+	int irq = regs->orig_eax & 0xff; /* high bits used in ret_from_ code  */
 	irq_desc_t *desc = irq_desc + irq;
 	struct irqaction * action;
 	unsigned int status;

@@ -490,7 +491,7 @@
 		irqreturn_t action_ret;
 
 		spin_unlock(&desc->lock);
-		action_ret = handle_IRQ_event(irq, &regs, action);
+		action_ret = handle_IRQ_event(irq, regs, action);
 		spin_lock(&desc->lock);
 		if (!noirqdebug)
 			note_interrupt(irq, desc, action_ret);

@@ -509,6 +510,8 @@
 	spin_unlock(&desc->lock);
 
 	irq_exit();
+
+	kgdb_process_breakpoint();
 
 	return 1;
 }

@@ -25,6 +25,7 @@
 #include <linux/module.h>
 #include <linux/nmi.h>
 #include <linux/sysdev.h>
+#include <linux/debugger.h>
 
 #include <asm/smp.h>
 #include <asm/mtrr.h>

@@ -420,14 +421,25 @@
 	int sum, cpu = smp_processor_id();
 
 	sum = irq_stat[cpu].apic_timer_irqs;
+	if (atomic_read(&debugger_active)) {
 
-	if (last_irq_sums[cpu] == sum) {
+		/*
+		 * The machine is in debugger, hold this cpu if already
+		 * not held.
+		 */
+		debugger_nmihook(cpu, regs);
+		alert_counter[cpu] = 0;
+
+	} else if (last_irq_sums[cpu] == sum) {
 		/*
 		 * Ayiee, looks like this CPU is stuck ...
 		 * wait a few IRQs (5 seconds) before doing the oops ...
 		 */
 		alert_counter[cpu]++;
 		if (alert_counter[cpu] == 5*nmi_hz) {
+
+			CHK_DEBUGGER(2,SIGSEGV,0,regs,)
+
 			spin_lock(&nmi_print_lock);
 			/*
 			 * We are in trouble anyway, lets at least try

@@ -578,7 +578,8 @@
 		 * have been cleared if the watchpoint triggered
 		 * inside the kernel.
 		 */
-		__asm__("movl %0,%%db7"	: : "r" (current->thread.debugreg[7]));
+		if (current->thread.debugreg[7])
+			__asm__("movl %0,%%db7"	: : "r" (current->thread.debugreg[7]));
 
 		/* Whee!  Actually deliver the signal.  */
 		handle_signal(signr, &info, oldset, regs);

@@ -51,6 +51,7 @@
 
 #include <linux/irq.h>
 #include <linux/module.h>
+#include <linux/debugger.h>
 
 #include "mach_traps.h"
 

@@ -258,6 +259,7 @@
 	static int die_counter;
 	int nl = 0;
 
+	CHK_DEBUGGER(1,SIGTRAP,err,regs,)
 	console_verbose();
 	spin_lock_irq(&die_lock);
 	bust_spinlocks(1);

@@ -346,6 +348,7 @@
 #define DO_ERROR(trapnr, signr, str, name) \
 asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
 { \
+	CHK_DEBUGGER(trapnr,signr,error_code,regs,)\
 	do_trap(trapnr, signr, str, 0, regs, error_code, NULL); \
 }
 

@@ -363,7 +366,9 @@
 #define DO_VM86_ERROR(trapnr, signr, str, name) \
 asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
 { \
+	CHK_DEBUGGER(trapnr,signr,error_code,regs,goto skip_trap)\
 	do_trap(trapnr, signr, str, 1, regs, error_code, NULL); \
+skip_trap: \
 	return; \
 }
 

@@ -572,7 +577,7 @@
 	tsk->thread.debugreg[6] = condition;
 
 	/* Mask out spurious TF errors due to lazy TF clearing */
-	if (condition & DR_STEP) {
+	if (condition & DR_STEP && !debugger_step) {
 		/*
 		 * The TF error should be masked out only if the current
 		 * process is not traced and if the TRAP flag has been set

@@ -595,11 +600,13 @@
 	info.si_errno = 0;
 	info.si_code = TRAP_BRKPT;
 	
-	/* If this is a kernel mode trap, save the user PC on entry to 
-	 * the kernel, that's what the debugger can make sense of.
-	 */
-	info.si_addr = ((regs->xcs & 3) == 0) ? (void *)tsk->thread.eip : 
-	                                        (void *)regs->eip;
+
+	/* If this is a kernel mode trap, we need to reset db7 to allow us
+	 * to continue sanely */
+	if ((regs->xcs & 3) == 0)
+		goto clear_dr7;
+
+	info.si_addr = (void *)regs->eip;
 	force_sig_info(SIGTRAP, &info, tsk);
 
 	/* Disable additional traps. They'll be re-enabled when

@@ -609,6 +616,7 @@
 	__asm__("movl %0,%%db7"
 		: /* no output */
 		: "r" (0));
+	CHK_DEBUGGER(1,SIGTRAP,error_code,regs,)
 	return;
 
 debug_vm86:

@@ -2,6 +2,11 @@
  *  linux/arch/i386/mm/fault.c
  *
  *  Copyright (C) 1995  Linus Torvalds
+ *
+ *  Change History
+ *
+ *	Tigran Aivazian <[email protected]>	Remote debugging support.
+ *
  */
 
 #include <linux/signal.h>

@@ -21,6 +26,7 @@
 #include <linux/vt_kern.h>		/* For unblank_screen() */
 #include <linux/highmem.h>
 #include <linux/module.h>
+#include <linux/debugger.h>
 
 #include <asm/system.h>
 #include <asm/uaccess.h>

@@ -289,6 +295,12 @@
 	if (in_atomic() || !mm)
 		goto bad_area_nosemaphore;
 
+	if (debugger_memerr_expected) {
+		/* This fault was caused by memory access through a debugger.
+		 * Don't handle it like user accesses */
+		goto no_context;
+	}
+
 	down_read(&mm->mmap_sem);
 
 	vma = find_vma(mm, address);

@@ -426,12 +438,15 @@
  	if (is_prefetch(regs, address))
  		return;
 
+	CHK_DEBUGGER(14, SIGSEGV,error_code, regs,)
+
 /*
  * Oops. The kernel tried to access some bad page. We'll have to
  * terminate things with extreme prejudice.
  */
 
 	bust_spinlocks(1);
+
 
 	if (address < PAGE_SIZE)
 		printk(KERN_ALERT "Unable to handle kernel NULL pointer dereference");

53 lines not on this page · raw message

@@ -423,6 +423,7 @@
 	unsigned int		saved_fs, saved_gs;
 /* IO permissions */
 	unsigned long	*io_bitmap_ptr;
+	void *		debuggerinfo;
 };
 
 #define INIT_THREAD  {							\