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-rw-r--r--drivers/tty/serial/kgdb_nmi.c2
-rw-r--r--drivers/tty/serial/kgdboc.c32
-rw-r--r--drivers/usb/early/ehci-dbgp.c3
-rw-r--r--include/linux/kgdb.h5
-rw-r--r--kernel/debug/debug_core.c4
-rw-r--r--kernel/debug/kdb/kdb_io.c72
6 files changed, 68 insertions, 50 deletions
diff --git a/drivers/tty/serial/kgdb_nmi.c b/drivers/tty/serial/kgdb_nmi.c
index 5022447afa23..6004c0c1d173 100644
--- a/drivers/tty/serial/kgdb_nmi.c
+++ b/drivers/tty/serial/kgdb_nmi.c
@@ -50,7 +50,7 @@ static int kgdb_nmi_console_setup(struct console *co, char *options)
* I/O utilities that messages sent to the console will automatically
* be displayed on the dbg_io.
*/
- dbg_io_ops->is_console = true;
+ dbg_io_ops->cons = co;
return 0;
}
diff --git a/drivers/tty/serial/kgdboc.c b/drivers/tty/serial/kgdboc.c
index 41396982e9e0..84ffede27f23 100644
--- a/drivers/tty/serial/kgdboc.c
+++ b/drivers/tty/serial/kgdboc.c
@@ -45,7 +45,6 @@ static struct platform_device *kgdboc_pdev;
#if IS_BUILTIN(CONFIG_KGDB_SERIAL_CONSOLE)
static struct kgdb_io kgdboc_earlycon_io_ops;
-static struct console *earlycon;
static int (*earlycon_orig_exit)(struct console *con);
#endif /* IS_BUILTIN(CONFIG_KGDB_SERIAL_CONSOLE) */
@@ -145,7 +144,7 @@ static void kgdboc_unregister_kbd(void)
#if IS_BUILTIN(CONFIG_KGDB_SERIAL_CONSOLE)
static void cleanup_earlycon(void)
{
- if (earlycon)
+ if (kgdboc_earlycon_io_ops.cons)
kgdb_unregister_io_module(&kgdboc_earlycon_io_ops);
}
#else /* !IS_BUILTIN(CONFIG_KGDB_SERIAL_CONSOLE) */
@@ -178,7 +177,7 @@ static int configure_kgdboc(void)
goto noconfig;
}
- kgdboc_io_ops.is_console = 0;
+ kgdboc_io_ops.cons = NULL;
kgdb_tty_driver = NULL;
kgdboc_use_kms = 0;
@@ -198,7 +197,7 @@ static int configure_kgdboc(void)
int idx;
if (cons->device && cons->device(cons, &idx) == p &&
idx == tty_line) {
- kgdboc_io_ops.is_console = 1;
+ kgdboc_io_ops.cons = cons;
break;
}
}
@@ -433,7 +432,8 @@ static int kgdboc_earlycon_get_char(void)
{
char c;
- if (!earlycon->read(earlycon, &c, 1))
+ if (!kgdboc_earlycon_io_ops.cons->read(kgdboc_earlycon_io_ops.cons,
+ &c, 1))
return NO_POLL_CHAR;
return c;
@@ -441,7 +441,8 @@ static int kgdboc_earlycon_get_char(void)
static void kgdboc_earlycon_put_char(u8 chr)
{
- earlycon->write(earlycon, &chr, 1);
+ kgdboc_earlycon_io_ops.cons->write(kgdboc_earlycon_io_ops.cons, &chr,
+ 1);
}
static void kgdboc_earlycon_pre_exp_handler(void)
@@ -461,7 +462,7 @@ static void kgdboc_earlycon_pre_exp_handler(void)
* boot if we detect this case.
*/
for_each_console(con)
- if (con == earlycon)
+ if (con == kgdboc_earlycon_io_ops.cons)
return;
already_warned = true;
@@ -484,25 +485,25 @@ static int kgdboc_earlycon_deferred_exit(struct console *con)
static void kgdboc_earlycon_deinit(void)
{
- if (!earlycon)
+ if (!kgdboc_earlycon_io_ops.cons)
return;
- if (earlycon->exit == kgdboc_earlycon_deferred_exit)
+ if (kgdboc_earlycon_io_ops.cons->exit == kgdboc_earlycon_deferred_exit)
/*
* kgdboc_earlycon is exiting but original boot console exit
* was never called (AKA kgdboc_earlycon_deferred_exit()
* didn't ever run). Undo our trap.
*/
- earlycon->exit = earlycon_orig_exit;
- else if (earlycon->exit)
+ kgdboc_earlycon_io_ops.cons->exit = earlycon_orig_exit;
+ else if (kgdboc_earlycon_io_ops.cons->exit)
/*
* We skipped calling the exit() routine so we could try to
* keep using the boot console even after it went away. We're
* finally done so call the function now.
*/
- earlycon->exit(earlycon);
+ kgdboc_earlycon_io_ops.cons->exit(kgdboc_earlycon_io_ops.cons);
- earlycon = NULL;
+ kgdboc_earlycon_io_ops.cons = NULL;
}
static struct kgdb_io kgdboc_earlycon_io_ops = {
@@ -511,7 +512,6 @@ static struct kgdb_io kgdboc_earlycon_io_ops = {
.write_char = kgdboc_earlycon_put_char,
.pre_exception = kgdboc_earlycon_pre_exp_handler,
.deinit = kgdboc_earlycon_deinit,
- .is_console = true,
};
#define MAX_CONSOLE_NAME_LEN (sizeof((struct console *) 0)->name)
@@ -557,10 +557,10 @@ static int __init kgdboc_earlycon_init(char *opt)
goto unlock;
}
- earlycon = con;
+ kgdboc_earlycon_io_ops.cons = con;
pr_info("Going to register kgdb with earlycon '%s'\n", con->name);
if (kgdb_register_io_module(&kgdboc_earlycon_io_ops) != 0) {
- earlycon = NULL;
+ kgdboc_earlycon_io_ops.cons = NULL;
pr_info("Failed to register kgdb with earlycon\n");
} else {
/* Trap exit so we can keep earlycon longer if needed. */
diff --git a/drivers/usb/early/ehci-dbgp.c b/drivers/usb/early/ehci-dbgp.c
index ea0d531c63e2..775cf70cfb3e 100644
--- a/drivers/usb/early/ehci-dbgp.c
+++ b/drivers/usb/early/ehci-dbgp.c
@@ -1058,7 +1058,8 @@ static int __init kgdbdbgp_parse_config(char *str)
kgdbdbgp_wait_time = simple_strtoul(ptr, &ptr, 10);
}
kgdb_register_io_module(&kgdbdbgp_io_ops);
- kgdbdbgp_io_ops.is_console = early_dbgp_console.index != -1;
+ if (early_dbgp_console.index != -1)
+ kgdbdbgp_io_ops.cons = &early_dbgp_console;
return 0;
}
diff --git a/include/linux/kgdb.h b/include/linux/kgdb.h
index c62d76478adc..529116b0cabe 100644
--- a/include/linux/kgdb.h
+++ b/include/linux/kgdb.h
@@ -276,8 +276,7 @@ struct kgdb_arch {
* the I/O driver.
* @post_exception: Pointer to a function that will do any cleanup work
* for the I/O driver.
- * @is_console: 1 if the end device is a console 0 if the I/O device is
- * not a console
+ * @cons: valid if the I/O device is a console; else NULL.
*/
struct kgdb_io {
const char *name;
@@ -288,7 +287,7 @@ struct kgdb_io {
void (*deinit) (void);
void (*pre_exception) (void);
void (*post_exception) (void);
- int is_console;
+ struct console *cons;
};
extern const struct kgdb_arch arch_kgdb_ops;
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);