3 files changed, 49 insertions, 33 deletions

diff --git a/kernel/debug/kdb/kdb_io.c b/kernel/debug/kdb/kdb_io.c
index 924bc9298a42..683a799618ad 100644
--- a/kernel/debug/kdb/kdb_io.c
+++ b/kernel/debug/kdb/kdb_io.c
@@ -542,6 +542,44 @@ static int kdb_search_string(char *searched, char *searchfor)
 	return 0;
 }
 
+static void kdb_msg_write(const char *msg, int msg_len)
+{
+	struct console *c;
+
+	if (msg_len == 0)
+		return;
+
+	if (dbg_io_ops) {
+		const char *cp = msg;
+		int len = msg_len;
+
+		while (len--) {
+			dbg_io_ops->write_char(*cp);
+			cp++;
+		}
+	}
+
+	for_each_console(c) {
+		if (!(c->flags & CON_ENABLED))
+			continue;
+		if (c == dbg_io_ops->cons)
+			continue;
+		/*
+		 * Set oops_in_progress to encourage the console drivers to
+		 * disregard their internal spin locks: in the current calling
+		 * context the risk of deadlock is a bigger problem than risks
+		 * due to re-entering the console driver. We operate directly on
+		 * oops_in_progress rather than using bust_spinlocks() because
+		 * the calls bust_spinlocks() makes on exit are not appropriate
+		 * for this calling context.
+		 */
+		++oops_in_progress;
+		c->write(c, msg, msg_len);
+		--oops_in_progress;
+		touch_nmi_watchdog();
+	}
+}
+
 int vkdb_printf(enum kdb_msgsrc src, const char *fmt, va_list ap)
 {
 	int diag;
@@ -553,7 +591,6 @@ int vkdb_printf(enum kdb_msgsrc src, const char *fmt, va_list ap)
 	int this_cpu, old_cpu;
 	char *cp, *cp2, *cphold = NULL, replaced_byte = ' ';
 	char *moreprompt = "more> ";
-	struct console *c;
 	unsigned long uninitialized_var(flags);
 
 	/* Serialize kdb_printf if multiple cpus try to write at once.
@@ -687,22 +724,11 @@ kdb_printit:
 	 */
 	retlen = strlen(kdb_buffer);
 	cp = (char *) printk_skip_headers(kdb_buffer);
-	if (!dbg_kdb_mode && kgdb_connected) {
+	if (!dbg_kdb_mode && kgdb_connected)
 		gdbstub_msg_write(cp, retlen - (cp - kdb_buffer));
-	} else {
-		if (dbg_io_ops && !dbg_io_ops->is_console) {
-			len = retlen - (cp - kdb_buffer);
-			cp2 = cp;
-			while (len--) {
-				dbg_io_ops->write_char(*cp2);
-				cp2++;
-			}
-		}
-		for_each_console(c) {
-			c->write(c, cp, retlen - (cp - kdb_buffer));
-			touch_nmi_watchdog();
-		}
-	}
+	else
+		kdb_msg_write(cp, retlen - (cp - kdb_buffer));
+
 	if (logging) {
 		saved_loglevel = console_loglevel;
 		console_loglevel = CONSOLE_LOGLEVEL_SILENT;
@@ -751,19 +777,7 @@ kdb_printit:
 			moreprompt = "more> ";
 
 		kdb_input_flush();
-
-		if (dbg_io_ops && !dbg_io_ops->is_console) {
-			len = strlen(moreprompt);
-			cp = moreprompt;
-			while (len--) {
-				dbg_io_ops->write_char(*cp);
-				cp++;
-			}
-		}
-		for_each_console(c) {
-			c->write(c, moreprompt, strlen(moreprompt));
-			touch_nmi_watchdog();
-		}
+		kdb_msg_write(moreprompt, strlen(moreprompt));
 
 		if (logging)
 			printk("%s", moreprompt);
diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c
index ec190569f690..5c7949061671 100644
--- a/kernel/debug/kdb/kdb_main.c
+++ b/kernel/debug/kdb/kdb_main.c
@@ -2326,7 +2326,8 @@ void kdb_ps1(const struct task_struct *p)
 	int cpu;
 	unsigned long tmp;
 
-	if (!p || probe_kernel_read(&tmp, (char *)p, sizeof(unsigned long)))
+	if (!p ||
+	    copy_from_kernel_nofault(&tmp, (char *)p, sizeof(unsigned long)))
 		return;
 
 	cpu = kdb_process_cpu(p);
diff --git a/kernel/debug/kdb/kdb_support.c b/kernel/debug/kdb/kdb_support.c
index b8e6306e7e13..004c5b6c87f8 100644
--- a/kernel/debug/kdb/kdb_support.c
+++ b/kernel/debug/kdb/kdb_support.c
@@ -325,7 +325,7 @@ char *kdb_strdup(const char *str, gfp_t type)
  */
 int kdb_getarea_size(void *res, unsigned long addr, size_t size)
 {
-	int ret = probe_kernel_read((char *)res, (char *)addr, size);
+	int ret = copy_from_kernel_nofault((char *)res, (char *)addr, size);
 	if (ret) {
 		if (!KDB_STATE(SUPPRESS)) {
 			kdb_printf("kdb_getarea: Bad address 0x%lx\n", addr);
@@ -350,7 +350,7 @@ int kdb_getarea_size(void *res, unsigned long addr, size_t size)
  */
 int kdb_putarea_size(unsigned long addr, void *res, size_t size)
 {
-	int ret = probe_kernel_read((char *)addr, (char *)res, size);
+	int ret = copy_from_kernel_nofault((char *)addr, (char *)res, size);
 	if (ret) {
 		if (!KDB_STATE(SUPPRESS)) {
 			kdb_printf("kdb_putarea: Bad address 0x%lx\n", addr);
@@ -624,7 +624,8 @@ char kdb_task_state_char (const struct task_struct *p)
 	char state;
 	unsigned long tmp;
 
-	if (!p || probe_kernel_read(&tmp, (char *)p, sizeof(unsigned long)))
+	if (!p ||
+	    copy_from_kernel_nofault(&tmp, (char *)p, sizeof(unsigned long)))
 		return 'E';
 
 	cpu = kdb_process_cpu(p);