static struct console_cmdline console_cmdline[MAX_CMDLINECONSOLES];
static int preferred_console = -1;
+static bool has_preferred_console;
int console_set_on_cmdline;
EXPORT_SYMBOL(console_set_on_cmdline);
static char *log_buf = __log_buf;
static u32 log_buf_len = __LOG_BUF_LEN;
+/*
+ * We cannot access per-CPU data (e.g. per-CPU flush irq_work) before
+ * per_cpu_areas are initialised. This variable is set to true when
+ * it's safe to access per-CPU data.
+ */
+static bool __printk_percpu_data_ready __read_mostly;
+
+bool printk_percpu_data_ready(void)
+{
+ return __printk_percpu_data_ready;
+}
+
/* Return log buffer address */
char *log_buf_addr_get(void)
{
user->idx = log_next_idx;
user->seq = log_next_seq;
break;
+ case SEEK_CUR:
+ /*
+ * It isn't supported due to the record nature of this
+ * interface: _SET _DATA and _END point to very specific
+ * record positions, while _CUR would be more useful in case
+ * of a byte-based log. Because of that, return the default
+ * errno value for invalid seek operation.
+ */
+ ret = -ESPIPE;
+ break;
default:
ret = -EINVAL;
}
static inline void log_buf_add_cpu(void) {}
#endif /* CONFIG_SMP */
+static void __init set_percpu_data_ready(void)
+{
+ printk_safe_init();
+ /* Make sure we set this flag only after printk_safe() init is done */
+ barrier();
+ __printk_percpu_data_ready = true;
+}
+
void __init setup_log_buf(int early)
{
unsigned long flags;
char *new_log_buf;
unsigned int free;
+ /*
+ * Some archs call setup_log_buf() multiple times - first is very
+ * early, e.g. from setup_arch(), and second - when percpu_areas
+ * are initialised.
+ */
+ if (!early)
+ set_percpu_data_ready();
+
if (log_buf != __log_buf)
return;
#endif
static int __add_preferred_console(char *name, int idx, char *options,
- char *brl_options)
+ char *brl_options, bool user_specified)
{
struct console_cmdline *c;
int i;
if (strcmp(c->name, name) == 0 && c->index == idx) {
if (!brl_options)
preferred_console = i;
+ if (user_specified)
+ c->user_specified = true;
return 0;
}
}
preferred_console = i;
strlcpy(c->name, name, sizeof(c->name));
c->options = options;
+ c->user_specified = user_specified;
braille_set_options(c, brl_options);
c->index = idx;
char *s, *options, *brl_options = NULL;
int idx;
+ if (str[0] == 0)
+ return 1;
+
if (_braille_console_setup(&str, &brl_options))
return 1;
idx = simple_strtoul(s, NULL, 10);
*s = 0;
- __add_preferred_console(buf, idx, options, brl_options);
+ __add_preferred_console(buf, idx, options, brl_options, true);
console_set_on_cmdline = 1;
return 1;
}
*/
int add_preferred_console(char *name, int idx, char *options)
{
- return __add_preferred_console(name, idx, options, NULL);
+ return __add_preferred_console(name, idx, options, NULL, false);
}
bool console_suspend_enabled = true;
printk_safe_enter_irqsave(flags);
raw_spin_lock(&logbuf_lock);
if (console_seq < log_first_seq) {
- len = sprintf(text,
- "** %llu printk messages dropped **\n",
- log_first_seq - console_seq);
+ len = snprintf(text, sizeof(text),
+ "** %llu printk messages dropped **\n",
+ log_first_seq - console_seq);
/* messages are gone, move to first one */
console_seq = log_first_seq;
early_param("keep_bootcon", keep_bootcon_setup);
+/*
+ * This is called by register_console() to try to match
+ * the newly registered console with any of the ones selected
+ * by either the command line or add_preferred_console() and
+ * setup/enable it.
+ *
+ * Care need to be taken with consoles that are statically
+ * enabled such as netconsole
+ */
+static int try_enable_new_console(struct console *newcon, bool user_specified)
+{
+ struct console_cmdline *c;
+ int i;
+
+ for (i = 0, c = console_cmdline;
+ i < MAX_CMDLINECONSOLES && c->name[0];
+ i++, c++) {
+ if (c->user_specified != user_specified)
+ continue;
+ if (!newcon->match ||
+ newcon->match(newcon, c->name, c->index, c->options) != 0) {
+ /* default matching */
+ BUILD_BUG_ON(sizeof(c->name) != sizeof(newcon->name));
+ if (strcmp(c->name, newcon->name) != 0)
+ continue;
+ if (newcon->index >= 0 &&
+ newcon->index != c->index)
+ continue;
+ if (newcon->index < 0)
+ newcon->index = c->index;
+
+ if (_braille_register_console(newcon, c))
+ return 0;
+
+ if (newcon->setup &&
+ newcon->setup(newcon, c->options) != 0)
+ return -EIO;
+ }
+ newcon->flags |= CON_ENABLED;
+ if (i == preferred_console) {
+ newcon->flags |= CON_CONSDEV;
+ has_preferred_console = true;
+ }
+ return 0;
+ }
+
+ /*
+ * Some consoles, such as pstore and netconsole, can be enabled even
+ * without matching. Accept the pre-enabled consoles only when match()
+ * and setup() had a change to be called.
+ */
+ if (newcon->flags & CON_ENABLED && c->user_specified == user_specified)
+ return 0;
+
+ return -ENOENT;
+}
+
/*
* The console driver calls this routine during kernel initialization
* to register the console printing procedure with printk() and to
*/
void register_console(struct console *newcon)
{
- int i;
unsigned long flags;
struct console *bcon = NULL;
- struct console_cmdline *c;
- static bool has_preferred;
+ int err;
for_each_console(bcon) {
if (WARN(bcon == newcon, "console '%s%d' already registered\n",
if (console_drivers && console_drivers->flags & CON_BOOT)
bcon = console_drivers;
- if (!has_preferred || bcon || !console_drivers)
- has_preferred = preferred_console >= 0;
+ if (!has_preferred_console || bcon || !console_drivers)
+ has_preferred_console = preferred_console >= 0;
/*
* See if we want to use this console driver. If we
* didn't select a console we take the first one
* that registers here.
*/
- if (!has_preferred) {
+ if (!has_preferred_console) {
if (newcon->index < 0)
newcon->index = 0;
if (newcon->setup == NULL ||
newcon->flags |= CON_ENABLED;
if (newcon->device) {
newcon->flags |= CON_CONSDEV;
- has_preferred = true;
+ has_preferred_console = true;
}
}
}
- /*
- * See if this console matches one we selected on
- * the command line.
- */
- for (i = 0, c = console_cmdline;
- i < MAX_CMDLINECONSOLES && c->name[0];
- i++, c++) {
- if (!newcon->match ||
- newcon->match(newcon, c->name, c->index, c->options) != 0) {
- /* default matching */
- BUILD_BUG_ON(sizeof(c->name) != sizeof(newcon->name));
- if (strcmp(c->name, newcon->name) != 0)
- continue;
- if (newcon->index >= 0 &&
- newcon->index != c->index)
- continue;
- if (newcon->index < 0)
- newcon->index = c->index;
-
- if (_braille_register_console(newcon, c))
- return;
+ /* See if this console matches one we selected on the command line */
+ err = try_enable_new_console(newcon, true);
- if (newcon->setup &&
- newcon->setup(newcon, c->options) != 0)
- break;
- }
+ /* If not, try to match against the platform default(s) */
+ if (err == -ENOENT)
+ err = try_enable_new_console(newcon, false);
- newcon->flags |= CON_ENABLED;
- if (i == preferred_console) {
- newcon->flags |= CON_CONSDEV;
- has_preferred = true;
- }
- break;
- }
-
- if (!(newcon->flags & CON_ENABLED))
+ /* printk() messages are not printed to the Braille console. */
+ if (err || newcon->flags & CON_BRL)
return;
/*
console_drivers = newcon;
if (newcon->next)
newcon->next->flags &= ~CON_CONSDEV;
+ /* Ensure this flag is always set for the head of the list */
+ newcon->flags |= CON_CONSDEV;
} else {
newcon->next = console_drivers->next;
console_drivers->next = newcon;
void wake_up_klogd(void)
{
+ if (!printk_percpu_data_ready())
+ return;
+
preempt_disable();
if (waitqueue_active(&log_wait)) {
this_cpu_or(printk_pending, PRINTK_PENDING_WAKEUP);
void defer_console_output(void)
{
+ if (!printk_percpu_data_ready())
+ return;
+
preempt_disable();
__this_cpu_or(printk_pending, PRINTK_PENDING_OUTPUT);
irq_work_queue(this_cpu_ptr(&wake_up_klogd_work));
EXPORT_SYMBOL_GPL(kmsg_dump_get_buffer);
/**
- * kmsg_dump_rewind_nolock - reset the interator (unlocked version)
+ * kmsg_dump_rewind_nolock - reset the iterator (unlocked version)
* @dumper: registered kmsg dumper
*
* Reset the dumper's iterator so that kmsg_dump_get_line() and
}
/**
- * kmsg_dump_rewind - reset the interator
+ * kmsg_dump_rewind - reset the iterator
* @dumper: registered kmsg dumper
*
* Reset the dumper's iterator so that kmsg_dump_get_line() and
projects / linux-block.git / blobdiff