From: Petr Mladek <pmladek@suse.com>
Date: Mon, 30 Aug 2021 14:36:10 +0000 (+0200)
Subject: Merge branch 'rework/printk_safe-removal' into for-linus
X-Git-Tag: accepted/tizen/unified/20230118.172025~6506^2
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=c985aafb60e972c0a6b8d0bd65e03af5890b748a;p=platform%2Fkernel%2Flinux-rpi.git

Merge branch 'rework/printk_safe-removal' into for-linus
---

c985aafb60e972c0a6b8d0bd65e03af5890b748a
diff --cc include/linux/printk.h
index da7a1de,a1379df..259af4f
--- a/include/linux/printk.h
+++ b/include/linux/printk.h
@@@ -170,8 -166,18 +158,18 @@@ int _printk(const char *fmt, ...)
  /*
   * Special printk facility for scheduler/timekeeping use only, _DO_NOT_USE_ !
   */
 -__printf(1, 2) __cold int printk_deferred(const char *fmt, ...);
 +__printf(1, 2) __cold int _printk_deferred(const char *fmt, ...);
  
+ extern void __printk_safe_enter(void);
+ extern void __printk_safe_exit(void);
+ /*
+  * The printk_deferred_enter/exit macros are available only as a hack for
+  * some code paths that need to defer all printk console printing. Interrupts
+  * must be disabled for the deferred duration.
+  */
+ #define printk_deferred_enter __printk_safe_enter
+ #define printk_deferred_exit __printk_safe_exit
+ 
  /*
   * Please don't use printk_ratelimit(), because it shares ratelimiting state
   * with all other unrelated printk_ratelimit() callsites.  Instead use
diff --cc kernel/printk/internal.h
index 1596e28,b6d310c..9f3ed2f
--- a/kernel/printk/internal.h
+++ b/kernel/printk/internal.h
@@@ -6,18 -6,6 +6,12 @@@
  
  #ifdef CONFIG_PRINTK
  
- #define PRINTK_SAFE_CONTEXT_MASK	0x007ffffff
- #define PRINTK_NMI_DIRECT_CONTEXT_MASK	0x008000000
- #define PRINTK_NMI_CONTEXT_MASK		0xff0000000
- 
- #define PRINTK_NMI_CONTEXT_OFFSET	0x010000000
- 
 +/* Flags for a single printk record. */
 +enum printk_info_flags {
 +	LOG_NEWLINE	= 2,	/* text ended with a newline */
 +	LOG_CONT	= 8,	/* text is a fragment of a continuation line */
 +};
 +
  __printf(4, 0)
  int vprintk_store(int facility, int level,
  		  const struct dev_printk_info *dev_info,
@@@ -43,22 -28,8 +34,10 @@@ bool printk_percpu_data_ready(void)
  		local_irq_restore(flags);	\
  	} while (0)
  
- #define printk_safe_enter_irq()		\
- 	do {					\
- 		local_irq_disable();		\
- 		__printk_safe_enter();		\
- 	} while (0)
- 
- #define printk_safe_exit_irq()			\
- 	do {					\
- 		__printk_safe_exit();		\
- 		local_irq_enable();		\
- 	} while (0)
- 
  void defer_console_output(void);
  
 +u16 printk_parse_prefix(const char *text, int *level,
 +			enum printk_info_flags *flags);
  #else
  
  /*
diff --cc kernel/printk/printk.c
index 776e356,65fffa6..825277e
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@@ -350,8 -350,13 +350,8 @@@ static int console_msg_format = MSG_FOR
   * non-prinatable characters are escaped in the "\xff" notation.
   */
  
 -enum log_flags {
 -	LOG_NEWLINE	= 2,	/* text ended with a newline */
 -	LOG_CONT	= 8,	/* text is a fragment of a continuation line */
 -};
 -
  /* syslog_lock protects syslog_* variables and write access to clear_seq. */
- static DEFINE_RAW_SPINLOCK(syslog_lock);
+ static DEFINE_MUTEX(syslog_lock);
  
  #ifdef CONFIG_PRINTK
  DECLARE_WAIT_QUEUE_HEAD(log_wait);
@@@ -2035,10 -2104,12 +2101,12 @@@ int vprintk_store(int facility, int lev
  {
  	const u32 caller_id = printk_caller_id();
  	struct prb_reserved_entry e;
 -	enum log_flags lflags = 0;
 +	enum printk_info_flags flags = 0;
  	struct printk_record r;
+ 	unsigned long irqflags;
  	u16 trunc_msg_len = 0;
  	char prefix_buf[8];
+ 	u8 *recursion_ptr;
  	u16 reserve_size;
  	va_list args2;
  	u16 text_len;
@@@ -2655,9 -2740,7 +2731,7 @@@ skip
  	 * there's a new owner and the console_unlock() from them will do the
  	 * flush, no worries.
  	 */
 -	retry = prb_read_valid(prb, console_seq, NULL);
 +	retry = prb_read_valid(prb, next_seq, NULL);
- 	printk_safe_exit_irqrestore(flags);
- 
  	if (retry && console_trylock())
  		goto again;
  }