[PATCH 2.6.26 2/25] mdb: Merkey's Kernel Debugger

From: jmerkey
Date: Sun Aug 03 2008 - 22:30:54 EST


Netware Style Debugger for Linux written by Jeffrey Vernon Merkey

--- linux-2.6.26/arch/x86/kernel/traps_32.c 2008-07-13
15:51:29.000000000 -0600
+++ linux-2.6.26-mdb/arch/x86/kernel/traps_32.c 2008-08-03
12:49:01.000000000 -0600
@@ -45,6 +45,16 @@
#include <linux/edac.h>
#endif

+#ifdef CONFIG_MDB
+#define DEBUGGER_EXCEPTION 1
+#define NMI_EXCEPTION 2
+#define BREAKPOINT_EXCEPTION 3
+#define SOFTWARE_EXCEPTION 22
+
+extern unsigned char *mdb_oops;
+extern int mdb(int reason, int error, void *frame);
+#endif
+
#include <asm/arch_hooks.h>
#include <asm/stacktrace.h>
#include <asm/processor.h>
@@ -467,6 +477,10 @@
die.lock_owner = -1;
add_taint(TAINT_DIE);
__raw_spin_unlock(&die.lock);
+#ifdef CONFIG_MDB
+ mdb_oops = (unsigned char *)str;
+ mdb(SOFTWARE_EXCEPTION, err, regs);
+#endif
raw_local_irq_restore(flags);

if (!regs)
@@ -592,7 +606,7 @@
}

DO_VM86_ERROR_INFO(0, SIGFPE, "divide error", divide_error, FPE_INTDIV,
regs->ip)
-#ifndef CONFIG_KPROBES
+#if !defined(CONFIG_KPROBES) && !defined(CONFIG_MDB)
DO_VM86_ERROR(3, SIGTRAP, "int3", int3)
#endif
DO_VM86_ERROR(4, SIGSEGV, "overflow", overflow)
@@ -733,6 +747,9 @@
{
if (notify_die(DIE_NMIUNKNOWN, "nmi", regs, reason, 2, SIGINT) ==
NOTIFY_STOP)
return;
+#ifdef CONFIG_MDB
+ mdb(NMI_EXCEPTION, reason, regs); // nmi is code 2
+#endif
#ifdef CONFIG_MCA
/*
* Might actually be able to figure out what the guilty party
@@ -771,6 +788,9 @@
printk(" on CPU%d, ip %08lx, registers:\n",
smp_processor_id(), regs->ip);
show_registers(regs);
+#ifdef CONFIG_MDB
+ mdb(NMI_EXCEPTION, 0, regs); // nmi is code 2
+#endif
console_silent();
spin_unlock(&nmi_print_lock);
bust_spinlocks(0);
@@ -795,6 +815,10 @@
if (!smp_processor_id())
reason = get_nmi_reason();

+#if defined(CONFIG_SMP) && defined(CONFIG_MDB)
+ if (mdb(NMI_EXCEPTION, 0, regs))
+ return;
+#endif
if (!(reason & 0xc0)) {
if (notify_die(DIE_NMI_IPI, "nmi_ipi", regs, reason, 2, SIGINT)
== NOTIFY_STOP)
@@ -860,6 +884,10 @@
#ifdef CONFIG_KPROBES
void __kprobes do_int3(struct pt_regs *regs, long error_code)
{
+#ifdef CONFIG_MDB
+ if (mdb(BREAKPOINT_EXCEPTION, error_code, regs))
+ return;
+#endif
trace_hardirqs_fixup();

if (notify_die(DIE_INT3, "int3", regs, error_code, 3, SIGTRAP)
@@ -875,6 +903,16 @@
}
#endif

+#if defined(CONFIG_MDB) && !defined(CONFIG_KPROBES)
+fastcall void do_int3(struct pt_regs * regs, long error_code)
+{
+#ifdef CONFIG_MDB
+ if (mdb(BREAKPOINT_EXCEPTION, error_code, regs))
+ return;
+#endif
+ do_trap(3, SIGTRAP, "int3", 1, regs, error_code, NULL);
+}
+#endif /* CONFIG_KDB && !CONFIG_KPROBES */
/*
* Our handling of the processor debug registers is non-trivial.
* We do not clear them on entry and exit from the kernel. Therefore
@@ -905,6 +943,10 @@
trace_hardirqs_fixup();

get_debugreg(condition, 6);
+#ifdef CONFIG_MDB
+ if (mdb(DEBUGGER_EXCEPTION, error_code, regs))
+ return;
+#endif

/*
* The processor cleared BTF, so don't mark that we need it set.

By making a contribution to this project, I certify that the contribution
was created in whole or in part by me and I have the right to submit it
under the open source license indicated in the file

Jeffrey Vernon Merkey





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