4 files changed, 47 insertions, 28 deletions
diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c
index 0557f24c6bca..17e073c309e6 100644
--- a/kernel/debug/debug_core.c
+++ b/kernel/debug/debug_core.c
@@ -672,6 +672,10 @@ kgdb_handle_exception(int evector, int signo, int ecode, struct pt_regs *regs)
 {
 	struct kgdb_state kgdb_var;
 	struct kgdb_state *ks = &kgdb_var;
+	int ret = 0;
+
+	if (arch_kgdb_ops.enable_nmi)
+		arch_kgdb_ops.enable_nmi(0);
 
 	ks->cpu			= raw_smp_processor_id();
 	ks->ex_vector		= evector;
@@ -681,11 +685,15 @@ kgdb_handle_exception(int evector, int signo, int ecode, struct pt_regs *regs)
 	ks->linux_regs		= regs;
 
 	if (kgdb_reenter_check(ks))
-		return 0; /* Ouch, double exception ! */
+		goto out; /* Ouch, double exception ! */
 	if (kgdb_info[ks->cpu].enter_kgdb != 0)
-		return 0;
+		goto out;
 
-	return kgdb_cpu_enter(ks, regs, DCPU_WANT_MASTER);
+	ret = kgdb_cpu_enter(ks, regs, DCPU_WANT_MASTER);
+out:
+	if (arch_kgdb_ops.enable_nmi)
+		arch_kgdb_ops.enable_nmi(1);
+	return ret;
 }
 
 int kgdb_nmicallback(int cpu, void *regs)
diff --git a/kernel/debug/kdb/kdb_debugger.c b/kernel/debug/kdb/kdb_debugger.c
index 8b68ce78ff17..be7b33b73d30 100644
--- a/kernel/debug/kdb/kdb_debugger.c
+++ b/kernel/debug/kdb/kdb_debugger.c
@@ -12,6 +12,7 @@
 #include <linux/kdb.h>
 #include <linux/kdebug.h>
 #include <linux/export.h>
+#include <linux/hardirq.h>
 #include "kdb_private.h"
 #include "../debug_core.h"
 
@@ -52,6 +53,9 @@ int kdb_stub(struct kgdb_state *ks)
 	if (atomic_read(&kgdb_setting_breakpoint))
 		reason = KDB_REASON_KEYBOARD;
 
+	if (in_nmi())
+		reason = KDB_REASON_NMI;
+
 	for (i = 0, bp = kdb_breakpoints; i < KDB_MAXBPT; i++, bp++) {
 		if ((bp->bp_enabled) && (bp->bp_addr == addr)) {
 			reason = KDB_REASON_BREAK;
diff --git a/kernel/debug/kdb/kdb_io.c b/kernel/debug/kdb/kdb_io.c
index bb9520f0f6ff..0a69d2adc4f3 100644
--- a/kernel/debug/kdb/kdb_io.c
+++ b/kernel/debug/kdb/kdb_io.c
@@ -715,9 +715,6 @@ kdb_printit:
 	/* check for having reached the LINES number of printed lines */
 	if (kdb_nextline == linecount) {
 		char buf1[16] = "";
-#if defined(CONFIG_SMP)
-		char buf2[32];
-#endif
 
 		/* Watch out for recursion here.  Any routine that calls
 		 * kdb_printf will come back through here.  And kdb_read
@@ -732,14 +729,6 @@ kdb_printit:
 		if (moreprompt == NULL)
 			moreprompt = "more> ";
 
-#if defined(CONFIG_SMP)
-		if (strchr(moreprompt, '%')) {
-			sprintf(buf2, moreprompt, get_cpu());
-			put_cpu();
-			moreprompt = buf2;
-		}
-#endif
-
 		kdb_input_flush();
 		c = console_drivers;
 
diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c
index 1f91413edb87..1261dc7eaeb9 100644
--- a/kernel/debug/kdb/kdb_main.c
+++ b/kernel/debug/kdb/kdb_main.c
@@ -21,6 +21,7 @@
 #include <linux/smp.h>
 #include <linux/utsname.h>
 #include <linux/vmalloc.h>
+#include <linux/atomic.h>
 #include <linux/module.h>
 #include <linux/mm.h>
 #include <linux/init.h>
@@ -139,11 +140,10 @@ static const int __nkdb_err = sizeof(kdbmsgs) / sizeof(kdbmsg_t);
 static char *__env[] = {
 #if defined(CONFIG_SMP)
  "PROMPT=[%d]kdb> ",
- "MOREPROMPT=[%d]more> ",
 #else
  "PROMPT=kdb> ",
- "MOREPROMPT=more> ",
 #endif
+ "MOREPROMPT=more> ",
  "RADIX=16",
  "MDCOUNT=8",			/* lines of md output */
  KDB_PLATFORM_ENV,
@@ -1236,18 +1236,6 @@ static int kdb_local(kdb_reason_t reason, int error, struct pt_regs *regs,
 		*cmdbuf = '\0';
 		*(cmd_hist[cmd_head]) = '\0';
 
-		if (KDB_FLAG(ONLY_DO_DUMP)) {
-			/* kdb is off but a catastrophic error requires a dump.
-			 * Take the dump and reboot.
-			 * Turn on logging so the kdb output appears in the log
-			 * buffer in the dump.
-			 */
-			const char *setargs[] = { "set", "LOGGING", "1" };
-			kdb_set(2, setargs);
-			kdb_reboot(0, NULL);
-			/*NOTREACHED*/
-		}
-
 do_full_getstr:
 #if defined(CONFIG_SMP)
 		snprintf(kdb_prompt_str, CMD_BUFLEN, kdbgetenv("PROMPT"),
@@ -2120,6 +2108,32 @@ static int kdb_dmesg(int argc, const char **argv)
 	return 0;
 }
 #endif /* CONFIG_PRINTK */
+
+/* Make sure we balance enable/disable calls, must disable first. */
+static atomic_t kdb_nmi_disabled;
+
+static int kdb_disable_nmi(int argc, const char *argv[])
+{
+	if (atomic_read(&kdb_nmi_disabled))
+		return 0;
+	atomic_set(&kdb_nmi_disabled, 1);
+	arch_kgdb_ops.enable_nmi(0);
+	return 0;
+}
+
+static int kdb_param_enable_nmi(const char *val, const struct kernel_param *kp)
+{
+	if (!atomic_add_unless(&kdb_nmi_disabled, -1, 0))
+		return -EINVAL;
+	arch_kgdb_ops.enable_nmi(1);
+	return 0;
+}
+
+static const struct kernel_param_ops kdb_param_ops_enable_nmi = {
+	.set = kdb_param_enable_nmi,
+};
+module_param_cb(enable_nmi, &kdb_param_ops_enable_nmi, NULL, 0600);
+
 /*
  * kdb_cpu - This function implements the 'cpu' command.
  *	cpu	[<cpunum>]
@@ -2864,6 +2878,10 @@ static void __init kdb_inittab(void)
 	kdb_register_repeat("dmesg", kdb_dmesg, "[lines]",
 	  "Display syslog buffer", 0, KDB_REPEAT_NONE);
 #endif
+	if (arch_kgdb_ops.enable_nmi) {
+		kdb_register_repeat("disable_nmi", kdb_disable_nmi, "",
+		  "Disable NMI entry to KDB", 0, KDB_REPEAT_NONE);
+	}
 	kdb_register_repeat("defcmd", kdb_defcmd, "name \"usage\" \"help\"",
 	  "Define a set of commands, down to endefcmd", 0, KDB_REPEAT_NONE);
 	kdb_register_repeat("kill", kdb_kill, "<-signal> <pid>",