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-rw-r--r--kernel/printk/console_cmdline.h1
-rw-r--r--kernel/printk/printk.c122
2 files changed, 79 insertions, 44 deletions
diff --git a/kernel/printk/console_cmdline.h b/kernel/printk/console_cmdline.h
index 11f19c466af5..3ca74ad391d6 100644
--- a/kernel/printk/console_cmdline.h
+++ b/kernel/printk/console_cmdline.h
@@ -6,6 +6,7 @@ struct console_cmdline
{
char name[16]; /* Name of the driver */
int index; /* Minor dev. to use */
+ bool user_specified; /* Specified by command line vs. platform */
char *options; /* Options for the driver */
#ifdef CONFIG_A11Y_BRAILLE_CONSOLE
char *brl_options; /* Options for braille driver */
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index a44094727a5c..c59d9a1567ad 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -280,6 +280,7 @@ static struct console *exclusive_console;
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);
@@ -2115,7 +2116,7 @@ asmlinkage __visible void early_printk(const char *fmt, ...)
#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;
@@ -2130,6 +2131,8 @@ static int __add_preferred_console(char *name, int idx, char *options,
if (strcmp(c->name, name) == 0 && c->index == idx) {
if (!brl_options)
preferred_console = i;
+ if (user_specified)
+ c->user_specified = true;
return 0;
}
}
@@ -2139,6 +2142,7 @@ static int __add_preferred_console(char *name, int idx, char *options,
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;
@@ -2193,7 +2197,7 @@ static int __init console_setup(char *str)
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;
}
@@ -2214,7 +2218,7 @@ __setup("console=", console_setup);
*/
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;
@@ -2627,6 +2631,63 @@ static int __init keep_bootcon_setup(char *str)
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
* print any messages that were printed by the kernel before the
@@ -2647,11 +2708,9 @@ early_param("keep_bootcon", keep_bootcon_setup);
*/
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;
if (console_drivers)
for_each_console(bcon)
@@ -2678,15 +2737,15 @@ void register_console(struct console *newcon)
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 ||
@@ -2694,47 +2753,20 @@ void register_console(struct console *newcon)
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;
-
- if (newcon->setup &&
- newcon->setup(newcon, c->options) != 0)
- break;
- }
+ /* See if this console matches one we selected on the command line */
+ err = try_enable_new_console(newcon, true);
- newcon->flags |= CON_ENABLED;
- if (i == preferred_console) {
- newcon->flags |= CON_CONSDEV;
- has_preferred = true;
- }
- break;
- }
+ /* If not, try to match against the platform default(s) */
+ if (err == -ENOENT)
+ err = try_enable_new_console(newcon, false);
- if (!(newcon->flags & CON_ENABLED))
+ /* printk() messages are not printed to the Braille console. */
+ if (err || newcon->flags & CON_BRL)
return;
/*
@@ -2756,6 +2788,8 @@ void register_console(struct console *newcon)
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;
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-25 17:39:55 +0100