Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull core debug changes from Ingo Molnar:
 "This contains mostly kernel debugging related updates:

   - make hung_task detection more configurable to distros
   - add final bits for x86 UV NMI debugging, with related KGDB changes
   - update the mailing-list of MAINTAINERS entries I'm involved with"

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  hung_task: Display every hung task warning
  sysctl: Add neg_one as a standard constraint
  x86/uv/nmi, kgdb/kdb: Fix UV NMI handler when KDB not configured
  x86/uv/nmi: Fix Sparse warnings
  kgdb/kdb: Fix no KDB config problem
  MAINTAINERS: Restore "L: linux-kernel@vger.kernel.org" entries

4 files changed, 12 insertions, 8 deletions

diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c
index 7d2f35e5df2f..334b3980ffc1 100644
--- a/kernel/debug/debug_core.c
+++ b/kernel/debug/debug_core.c
@@ -736,7 +736,8 @@ int kgdb_nmicallback(int cpu, void *regs)
 	return 1;
 }
 
-int kgdb_nmicallin(int cpu, int trapnr, void *regs, atomic_t *send_ready)
+int kgdb_nmicallin(int cpu, int trapnr, void *regs, int err_code,
+							atomic_t *send_ready)
 {
 #ifdef CONFIG_SMP
 	if (!kgdb_io_ready(0) || !send_ready)
@@ -750,7 +751,7 @@ int kgdb_nmicallin(int cpu, int trapnr, void *regs, atomic_t *send_ready)
 		ks->cpu			= cpu;
 		ks->ex_vector		= trapnr;
 		ks->signo		= SIGTRAP;
-		ks->err_code		= KGDB_KDB_REASON_SYSTEM_NMI;
+		ks->err_code		= err_code;
 		ks->linux_regs		= regs;
 		ks->send_ready		= send_ready;
 		kgdb_cpu_enter(ks, regs, DCPU_WANT_MASTER);
diff --git a/kernel/debug/debug_core.h b/kernel/debug/debug_core.h
index 572aa4f5677c..127d9bc49fb4 100644
--- a/kernel/debug/debug_core.h
+++ b/kernel/debug/debug_core.h
@@ -75,13 +75,11 @@ extern int kdb_stub(struct kgdb_state *ks);
 extern int kdb_parse(const char *cmdstr);
 extern int kdb_common_init_state(struct kgdb_state *ks);
 extern int kdb_common_deinit_state(void);
-#define KGDB_KDB_REASON_SYSTEM_NMI KDB_REASON_SYSTEM_NMI
 #else /* ! CONFIG_KGDB_KDB */
 static inline int kdb_stub(struct kgdb_state *ks)
 {
 	return DBG_PASS_EVENT;
 }
-#define KGDB_KDB_REASON_SYSTEM_NMI 0
 #endif /* CONFIG_KGDB_KDB */
 
 #endif /* _DEBUG_CORE_H_ */
diff --git a/kernel/hung_task.c b/kernel/hung_task.c
index 9328b80eaf14..0b9c169d577f 100644
--- a/kernel/hung_task.c
+++ b/kernel/hung_task.c
@@ -37,7 +37,7 @@ int __read_mostly sysctl_hung_task_check_count = PID_MAX_LIMIT;
  */
 unsigned long __read_mostly sysctl_hung_task_timeout_secs = CONFIG_DEFAULT_HUNG_TASK_TIMEOUT;
 
-unsigned long __read_mostly sysctl_hung_task_warnings = 10;
+int __read_mostly sysctl_hung_task_warnings = 10;
 
 static int __read_mostly did_panic;
 
@@ -98,7 +98,9 @@ static void check_hung_task(struct task_struct *t, unsigned long timeout)
 
 	if (!sysctl_hung_task_warnings)
 		return;
-	sysctl_hung_task_warnings--;
+
+	if (sysctl_hung_task_warnings > 0)
+		sysctl_hung_task_warnings--;
 
 	/*
 	 * Ok, the task did not get scheduled for more than 2 minutes,
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 096db7452cbd..49e13e1f8fe6 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -121,6 +121,8 @@ extern int blk_iopoll_enabled;
 static int sixty = 60;
 #endif
 
+static int __maybe_unused neg_one = -1;
+
 static int zero;
 static int __maybe_unused one = 1;
 static int __maybe_unused two = 2;
@@ -997,9 +999,10 @@ static struct ctl_table kern_table[] = {
 	{
 		.procname	= "hung_task_warnings",
 		.data		= &sysctl_hung_task_warnings,
-		.maxlen		= sizeof(unsigned long),
+		.maxlen		= sizeof(int),
 		.mode		= 0644,
-		.proc_handler	= proc_doulongvec_minmax,
+		.proc_handler	= proc_dointvec_minmax,
+		.extra1		= &neg_one,
 	},
 #endif
 #ifdef CONFIG_COMPAT