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Diffstat (limited to 'kernel')
-rw-r--r--kernel/debug/debug_core.c4
-rw-r--r--kernel/debug/kdb/kdb_io.c72
2 files changed, 47 insertions, 29 deletions
diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c
index bc8d25f2ac8a..9e5934780f41 100644
--- a/kernel/debug/debug_core.c
+++ b/kernel/debug/debug_core.c
@@ -587,6 +587,7 @@ static int kgdb_cpu_enter(struct kgdb_state *ks, struct pt_regs *regs,
arch_kgdb_ops.disable_hw_break(regs);
acquirelock:
+ rcu_read_lock();
/*
* Interrupts will be restored by the 'trap return' code, except when
* single stepping.
@@ -646,6 +647,7 @@ return_normal:
atomic_dec(&slaves_in_kgdb);
dbg_touch_watchdogs();
local_irq_restore(flags);
+ rcu_read_unlock();
return 0;
}
cpu_relax();
@@ -664,6 +666,7 @@ return_normal:
raw_spin_unlock(&dbg_master_lock);
dbg_touch_watchdogs();
local_irq_restore(flags);
+ rcu_read_unlock();
goto acquirelock;
}
@@ -787,6 +790,7 @@ kgdb_restore:
raw_spin_unlock(&dbg_master_lock);
dbg_touch_watchdogs();
local_irq_restore(flags);
+ rcu_read_unlock();
return kgdb_info[cpu].ret_state;
}
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);