Merge branch 'kdb-merge' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb

* 'kdb-merge' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb: (25 commits)
  kdb,debug_core: Allow the debug core to receive a panic notification
  MAINTAINERS: update kgdb, kdb, and debug_core info
  debug_core,kdb: Allow the debug core to process a recursive debug entry
  printk,kdb: capture printk() when in kdb shell
  kgdboc,kdb: Allow kdb to work on a non open console port
  kgdb: Add the ability to schedule a breakpoint via a tasklet
  mips,kgdb: kdb low level trap catch and stack trace
  powerpc,kgdb: Introduce low level trap catching
  x86,kgdb: Add low level debug hook
  kgdb: remove post_primary_code references
  kgdb,docs: Update the kgdb docs to include kdb
  kgdboc,keyboard: Keyboard driver for kdb with kgdb
  kgdb: gdb "monitor" -> kdb passthrough
  sparc,sunzilog: Add console polling support for sunzilog serial driver
  sh,sh-sci: Use NO_POLL_CHAR in the SCIF polled console code
  kgdb,8250,pl011: Return immediately from console poll
  kgdb: core changes to support kdb
  kdb: core for kgdb back end (2 of 2)
  kdb: core for kgdb back end (1 of 2)
  kgdb,blackfin: Add in kgdb_arch_set_pc for blackfin
  ...

3 files changed, 15 insertions, 4 deletions

diff --git a/arch/powerpc/include/asm/kmap_types.h b/arch/powerpc/include/asm/kmap_types.h
index 916369575c9..bca8fdcd254 100644
--- a/arch/powerpc/include/asm/kmap_types.h
+++ b/arch/powerpc/include/asm/kmap_types.h
@@ -26,6 +26,7 @@ enum km_type {
 	KM_SOFTIRQ1,
 	KM_PPC_SYNC_PAGE,
 	KM_PPC_SYNC_ICACHE,
+	KM_KDB,
 	KM_TYPE_NR
 };
 
diff --git a/arch/powerpc/kernel/kgdb.c b/arch/powerpc/kernel/kgdb.c
index 41bada0298c..82a7b228c81 100644
--- a/arch/powerpc/kernel/kgdb.c
+++ b/arch/powerpc/kernel/kgdb.c
@@ -20,6 +20,7 @@
 #include <linux/smp.h>
 #include <linux/signal.h>
 #include <linux/ptrace.h>
+#include <linux/kdebug.h>
 #include <asm/current.h>
 #include <asm/processor.h>
 #include <asm/machdep.h>
@@ -115,7 +116,8 @@ void kgdb_roundup_cpus(unsigned long flags)
 /* KGDB functions to use existing PowerPC64 hooks. */
 static int kgdb_debugger(struct pt_regs *regs)
 {
-	return kgdb_handle_exception(0, computeSignal(TRAP(regs)), 0, regs);
+	return !kgdb_handle_exception(1, computeSignal(TRAP(regs)),
+				      DIE_OOPS, regs);
 }
 
 static int kgdb_handle_breakpoint(struct pt_regs *regs)
@@ -123,7 +125,7 @@ static int kgdb_handle_breakpoint(struct pt_regs *regs)
 	if (user_mode(regs))
 		return 0;
 
-	if (kgdb_handle_exception(0, SIGTRAP, 0, regs) != 0)
+	if (kgdb_handle_exception(1, SIGTRAP, 0, regs) != 0)
 		return 0;
 
 	if (*(u32 *) (regs->nip) == *(u32 *) (&arch_kgdb_ops.gdb_bpt_instr))
@@ -309,6 +311,11 @@ void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs)
 	       (unsigned long)(((void *)gdb_regs) + NUMREGBYTES));
 }
 
+void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc)
+{
+	regs->nip = pc;
+}
+
 /*
  * This function does PowerPC specific procesing for interfacing to gdb.
  */
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index 29d128eb6c4..b6859aade9c 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -815,12 +815,15 @@ void __kprobes program_check_exception(struct pt_regs *regs)
 		return;
 	}
 	if (reason & REASON_TRAP) {
+		/* Debugger is first in line to stop recursive faults in
+		 * rcu_lock, notify_die, or atomic_notifier_call_chain */
+		if (debugger_bpt(regs))
+			return;
+
 		/* trap exception */
 		if (notify_die(DIE_BPT, "breakpoint", regs, 5, 5, SIGTRAP)
 				== NOTIFY_STOP)
 			return;
-		if (debugger_bpt(regs))
-			return;
 
 		if (!(regs->msr & MSR_PR) &&  /* not user-mode */
 		    report_bug(regs->nip, regs) == BUG_TRAP_TYPE_WARN) {