Merge tag 'printk-for-5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux

Pull printk updates from Petr Mladek:

 - Herbert Xu made printk header file self-contained.

 - Andy Shevchenko and Sergey Senozhatsky cleaned up console->setup()
   error handling.

 - Andy Shevchenko did some cleanups (e.g. sparse warning) in vsprintf
   code.

 - Minor documentation updates.

* tag 'printk-for-5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux:
  lib/vsprintf: Force type of flags value for gfp_t
  lib/vsprintf: Replace custom spec to print decimals with generic one
  lib/vsprintf: Replace hidden BUILD_BUG_ON() with static_assert()
  printk: Make linux/printk.h self-contained
  doc:kmsg: explicitly state the return value in case of SEEK_CUR
  Replace HTTP links with HTTPS ones: vsprintf
  hvc: unify console setup naming
  console: Fix trivia typo 'change' -> 'chance'
  console: Propagate error code from console ->setup()
  tty: hvc: Return proper error code from console ->setup() hook
  serial: sunzilog: Return proper error code from console ->setup() hook
  serial: sunsab: Return proper error code from console ->setup() hook
  mips: Return proper error code from console ->setup() hook

1 files changed, 12 insertions, 4 deletions

diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index b71eaf5f5a86..9b75f6bfc333 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -943,6 +943,14 @@ out:
 	return ret;
 }
 
+/*
+ * Be careful when modifying this function!!!
+ *
+ * Only few operations are supported because the device works only with the
+ * entire variable length messages (records). Non-standard values are
+ * returned in the other cases and has been this way for quite some time.
+ * User space applications might depend on this behavior.
+ */
 static loff_t devkmsg_llseek(struct file *file, loff_t offset, int whence)
 {
 	struct devkmsg_user *user = file->private_data;
@@ -2658,7 +2666,7 @@ early_param("keep_bootcon", keep_bootcon_setup);
 static int try_enable_new_console(struct console *newcon, bool user_specified)
 {
 	struct console_cmdline *c;
-	int i;
+	int i, err;
 
 	for (i = 0, c = console_cmdline;
 	     i < MAX_CMDLINECONSOLES && c->name[0];
@@ -2681,8 +2689,8 @@ static int try_enable_new_console(struct console *newcon, bool user_specified)
 				return 0;
 
 			if (newcon->setup &&
-			    newcon->setup(newcon, c->options) != 0)
-				return -EIO;
+			    (err = newcon->setup(newcon, c->options)) != 0)
+				return err;
 		}
 		newcon->flags |= CON_ENABLED;
 		if (i == preferred_console) {
@@ -2695,7 +2703,7 @@ static int try_enable_new_console(struct console *newcon, bool user_specified)
 	/*
 	 * 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.
+	 * and setup() had a chance to be called.
 	 */
 	if (newcon->flags & CON_ENABLED && c->user_specified ==	user_specified)
 		return 0;