[PATCH V2 00/23] printk: refactoring

[PATCH V2 00/23] printk: refactoring

[Joe Perches]

Make printk a bit more readable.

Created directory:
	kernel/printk
Created source files:
	printk.c		Generic printk and console routines
	printk_log.[ch]		Log buffer routines
	printk_syslog.[ch]	syslog(2) routines
	braille.c		Braille console support
	devkmsg.c		/dev/kmsg support
	kmsg_dump.c		kmsg_dump support

Changes from v1:
Fix braille.h: _braille_console_setup return value
Remove duplicated #define
Add missing #include <linux/uaccess.h>

Joe Perches (23):
  printk: Move to separate directory for easier modification
  printk: Add console_cmdline.h
  printk: Move braille console support into separate braille.[ch] files
  printk: Use pointer for console_cmdline indexing
  printk: rename struct log to struct printk_log
  printk: Rename log_buf and __LOG_BUF_LEN
  printk: Rename log_first and log_next variables
  printk: Rename log_<foo> variables and functions
  printk: Rename enum log_flags to printk_log_flags
  printk: Rename log_wait to printk_log_wait
  printk: Rename logbuf_lock to printk_logbuf_lock
  printk: Rename clear_seq and clear_idx variables
  printk: Remove static from printk_ variables
  printk: Rename LOG_ALIGN to PRINTK_LOG_ALIGN
  printk: Add and use printk_log.h
  printk: Add printk_log.c
  printk: Make wait_queue_head_t printk_log_wait extern
  printk: Rename and move 2 #defines to printk_log.h
  printk: Move devkmsg bits to separate file
  printk: Prefix print_time and msg_print_text with printk_
  printk: Move functions printk_print_time and printk_msg_print_text
  printk: Add printk_syslog.c and .h
  printk: Move kmsg_dump functions to separate file

 drivers/accessibility/braille/braille_console.c |    9 +-
 fs/proc/kmsg.c                                  |    4 +-
 kernel/Makefile                                 |    3 +-
 kernel/printk.c                                 | 2820 -----------------------
 kernel/printk/Makefile                          |    6 +
 kernel/printk/braille.c                         |   48 +
 kernel/printk/braille.h                         |   48 +
 kernel/printk/console_cmdline.h                 |   14 +
 kernel/printk/devkmsg.c                         |  309 +++
 kernel/printk/kmsg_dump.c                       |  328 +++
 kernel/printk/printk.c                          | 1513 ++++++++++++
 kernel/printk/printk_log.c                      |  263 +++
 kernel/printk/printk_log.h                      |  128 +
 kernel/printk/printk_syslog.c                   |  355 +++
 kernel/printk/printk_syslog.h                   |   13 +
 15 files changed, 3036 insertions(+), 2825 deletions(-)
 delete mode 100644 kernel/printk.c
 create mode 100644 kernel/printk/Makefile
 create mode 100644 kernel/printk/braille.c
 create mode 100644 kernel/printk/braille.h
 create mode 100644 kernel/printk/console_cmdline.h
 create mode 100644 kernel/printk/devkmsg.c
 create mode 100644 kernel/printk/kmsg_dump.c
 create mode 100644 kernel/printk/printk.c
 create mode 100644 kernel/printk/printk_log.c
 create mode 100644 kernel/printk/printk_log.h
 create mode 100644 kernel/printk/printk_syslog.c
 create mode 100644 kernel/printk/printk_syslog.h

-- 
1.7.8.112.g3fd21

[PATCH V2 01/23] printk: Move to separate directory for easier modification

[Joe Perches]

Make it easier to break up printk into bite-sized chunks.

Remove printk path/filename from comment.

Signed-off-by: Joe Perches <joe@perches.com>
---
 kernel/Makefile              |    3 ++-
 kernel/printk/Makefile       |    1 +
 kernel/{ => printk}/printk.c |    2 --
 3 files changed, 3 insertions(+), 3 deletions(-)
 create mode 100644 kernel/printk/Makefile
 rename kernel/{ => printk}/printk.c (99%)

diff --git a/kernel/Makefile b/kernel/Makefile
index 0dfeca4..d53980d 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -2,7 +2,7 @@
 # Makefile for the linux kernel.
 #
 
-obj-y     = fork.o exec_domain.o panic.o printk.o \
+obj-y     = fork.o exec_domain.o panic.o \
 	    cpu.o exit.o itimer.o time.o softirq.o resource.o \
 	    sysctl.o sysctl_binary.o capability.o ptrace.o timer.o user.o \
 	    signal.o sys.o kmod.o workqueue.o pid.o task_work.o \
@@ -24,6 +24,7 @@ endif
 
 obj-y += sched/
 obj-y += power/
+obj-y += printk/
 
 ifeq ($(CONFIG_CHECKPOINT_RESTORE),y)
 obj-$(CONFIG_X86) += kcmp.o
diff --git a/kernel/printk/Makefile b/kernel/printk/Makefile
new file mode 100644
index 0000000..36d306d
--- /dev/null
+++ b/kernel/printk/Makefile
@@ -0,0 +1 @@
+obj-y	= printk.o
diff --git a/kernel/printk.c b/kernel/printk/printk.c
similarity index 99%
rename from kernel/printk.c
rename to kernel/printk/printk.c
index 2d607f4..1950ecf 100644
--- a/kernel/printk.c
+++ b/kernel/printk/printk.c
@@ -1,6 +1,4 @@
 /*
- *  linux/kernel/printk.c
- *
  *  Copyright (C) 1991, 1992  Linus Torvalds
  *
  * Modified to make sys_syslog() more flexible: added commands to
-- 
1.7.8.112.g3fd21

[PATCH V2 02/23] printk: Add console_cmdline.h

[Joe Perches]

Add an include file for the console_cmdline struct
so that the braille console driver can be separated.

Signed-off-by: Joe Perches <joe@perches.com>
---
 kernel/printk/console_cmdline.h |   14 ++++++++++++++
 kernel/printk/printk.c          |   13 ++++---------
 2 files changed, 18 insertions(+), 9 deletions(-)
 create mode 100644 kernel/printk/console_cmdline.h

diff --git a/kernel/printk/console_cmdline.h b/kernel/printk/console_cmdline.h
new file mode 100644
index 0000000..cbd69d8
--- /dev/null
+++ b/kernel/printk/console_cmdline.h
@@ -0,0 +1,14 @@
+#ifndef _CONSOLE_CMDLINE_H
+#define _CONSOLE_CMDLINE_H
+
+struct console_cmdline
+{
+	char	name[8];			/* Name of the driver	    */
+	int	index;				/* Minor dev. to use	    */
+	char	*options;			/* Options for the driver   */
+#ifdef CONFIG_A11Y_BRAILLE_CONSOLE
+	char	*brl_options;			/* Options for braille driver */
+#endif
+};
+
+#endif
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 1950ecf..50ef6af 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -46,6 +46,8 @@
 #define CREATE_TRACE_POINTS
 #include <trace/events/printk.h>
 
+#include "console_cmdline.h"
+
 /*
  * Architectures can override it:
  */
@@ -100,22 +102,15 @@ static int console_locked, console_suspended;
  */
 static struct console *exclusive_console;
 
+
 /*
  *	Array of consoles built from command line options (console=)
  */
-struct console_cmdline
-{
-	char	name[8];			/* Name of the driver	    */
-	int	index;				/* Minor dev. to use	    */
-	char	*options;			/* Options for the driver   */
-#ifdef CONFIG_A11Y_BRAILLE_CONSOLE
-	char	*brl_options;			/* Options for braille driver */
-#endif
-};
 
 #define MAX_CMDLINECONSOLES 8
 
 static struct console_cmdline console_cmdline[MAX_CMDLINECONSOLES];
+
 static int selected_console = -1;
 static int preferred_console = -1;
 int console_set_on_cmdline;
-- 
1.7.8.112.g3fd21

[PATCH V2 03/23] printk: Move braille console support into separate braille.[ch] files

[Joe Perches]

Create files with prototypes and static inlines for braille
support.  Make braille_console functions return 1 on success.

Corrected CONFIG_A11Y_BRAILLE_CONSOLE=n _braille_console_setup
return value to NULL.

link:  http://lkml.kernel.org/r/1350999678-17441-1-git-send-email-ming.lei@canonical.com
cc: Samuel Thibault <samuel.thibault@ens-lyon.org>
cc: Ming Lei <ming.lei@canonical.com>

Signed-off-by: Joe Perches <joe@perches.com>
---
 drivers/accessibility/braille/braille_console.c |    9 +++-
 kernel/printk/Makefile                          |    1 +
 kernel/printk/braille.c                         |   48 +++++++++++++++++++++++
 kernel/printk/braille.h                         |   48 +++++++++++++++++++++++
 kernel/printk/printk.c                          |   44 ++++++---------------
 5 files changed, 117 insertions(+), 33 deletions(-)
 create mode 100644 kernel/printk/braille.c
 create mode 100644 kernel/printk/braille.h

diff --git a/drivers/accessibility/braille/braille_console.c b/drivers/accessibility/braille/braille_console.c
index d21167b..dc34a5b 100644
--- a/drivers/accessibility/braille/braille_console.c
+++ b/drivers/accessibility/braille/braille_console.c
@@ -359,6 +359,9 @@ int braille_register_console(struct console *console, int index,
 		char *console_options, char *braille_options)
 {
 	int ret;
+
+	if (!(console->flags & CON_BRL))
+		return 0;
 	if (!console_options)
 		/* Only support VisioBraille for now */
 		console_options = "57600o8";
@@ -374,15 +377,17 @@ int braille_register_console(struct console *console, int index,
 	braille_co = console;
 	register_keyboard_notifier(&keyboard_notifier_block);
 	register_vt_notifier(&vt_notifier_block);
-	return 0;
+	return 1;
 }
 
 int braille_unregister_console(struct console *console)
 {
 	if (braille_co != console)
 		return -EINVAL;
+	if (!(console->flags & CON_BRL))
+		return 0;
 	unregister_keyboard_notifier(&keyboard_notifier_block);
 	unregister_vt_notifier(&vt_notifier_block);
 	braille_co = NULL;
-	return 0;
+	return 1;
 }
diff --git a/kernel/printk/Makefile b/kernel/printk/Makefile
index 36d306d..85405bd 100644
--- a/kernel/printk/Makefile
+++ b/kernel/printk/Makefile
@@ -1 +1,2 @@
 obj-y	= printk.o
+obj-$(CONFIG_A11Y_BRAILLE_CONSOLE)	+= braille.o
diff --git a/kernel/printk/braille.c b/kernel/printk/braille.c
new file mode 100644
index 0000000..b51087f
--- /dev/null
+++ b/kernel/printk/braille.c
@@ -0,0 +1,48 @@
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/console.h>
+#include <linux/string.h>
+
+#include "console_cmdline.h"
+#include "braille.h"
+
+char *_braille_console_setup(char **str, char **brl_options)
+{
+	if (!memcmp(*str, "brl,", 4)) {
+		*brl_options = "";
+		*str += 4;
+	} else if (!memcmp(str, "brl=", 4)) {
+		*brl_options = *str + 4;
+		*str = strchr(*brl_options, ',');
+		if (!*str)
+			pr_err("need port name after brl=\n");
+		else
+			*((*str)++) = 0;
+	}
+
+	return *str;
+}
+
+int
+_braille_register_console(struct console *console, struct console_cmdline *c)
+{
+	int rtn = 0;
+
+	if (c->brl_options) {
+		console->flags |= CON_BRL;
+		rtn = braille_register_console(console, c->index, c->options,
+					       c->brl_options);
+	}
+
+	return rtn;
+}
+
+int
+_braille_unregister_console(struct console *console)
+{
+	if (console->flags & CON_BRL)
+		return braille_unregister_console(console);
+
+	return 0;
+}
diff --git a/kernel/printk/braille.h b/kernel/printk/braille.h
new file mode 100644
index 0000000..769d771
--- /dev/null
+++ b/kernel/printk/braille.h
@@ -0,0 +1,48 @@
+#ifndef _PRINTK_BRAILLE_H
+#define _PRINTK_BRAILLE_H
+
+#ifdef CONFIG_A11Y_BRAILLE_CONSOLE
+
+static inline void
+braille_set_options(struct console_cmdline *c, char *brl_options)
+{
+	c->brl_options = brl_options;
+}
+
+char *
+_braille_console_setup(char **str, char **brl_options);
+
+int
+_braille_register_console(struct console *console, struct console_cmdline *c);
+
+int
+_braille_unregister_console(struct console *console);
+
+#else
+
+static inline void
+braille_set_options(struct console_cmdline *c, char *brl_options)
+{
+}
+
+static inline char *
+_braille_console_setup(char **str, char **brl_options)
+{
+	return NULL;
+}
+
+static inline int
+_braille_register_console(struct console *console, struct console_cmdline *c)
+{
+	return 0;
+}
+
+static inline int
+_braille_unregister_console(struct console *console)
+{
+	return 0;
+}
+
+#endif
+
+#endif
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 50ef6af..df5b80f 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -47,6 +47,7 @@
 #include <trace/events/printk.h>
 
 #include "console_cmdline.h"
+#include "braille.h"
 
 /*
  * Architectures can override it:
@@ -1731,9 +1732,8 @@ static int __add_preferred_console(char *name, int idx, char *options,
 	c = &console_cmdline[i];
 	strlcpy(c->name, name, sizeof(c->name));
 	c->options = options;
-#ifdef CONFIG_A11Y_BRAILLE_CONSOLE
-	c->brl_options = brl_options;
-#endif
+	braille_set_options(c, brl_options);
+
 	c->index = idx;
 	return 0;
 }
@@ -1746,20 +1746,8 @@ static int __init console_setup(char *str)
 	char *s, *options, *brl_options = NULL;
 	int idx;
 
-#ifdef CONFIG_A11Y_BRAILLE_CONSOLE
-	if (!memcmp(str, "brl,", 4)) {
-		brl_options = "";
-		str += 4;
-	} else if (!memcmp(str, "brl=", 4)) {
-		brl_options = str + 4;
-		str = strchr(brl_options, ',');
-		if (!str) {
-			printk(KERN_ERR "need port name after brl=\n");
-			return 1;
-		}
-		*(str++) = 0;
-	}
-#endif
+	if (_braille_console_setup(&str, &brl_options))
+		return 1;
 
 	/*
 	 * Decode str into name, index, options.
@@ -2286,16 +2274,10 @@ void register_console(struct console *newcon)
 			continue;
 		if (newcon->index < 0)
 			newcon->index = console_cmdline[i].index;
-#ifdef CONFIG_A11Y_BRAILLE_CONSOLE
-		if (console_cmdline[i].brl_options) {
-			newcon->flags |= CON_BRL;
-			braille_register_console(newcon,
-					console_cmdline[i].index,
-					console_cmdline[i].options,
-					console_cmdline[i].brl_options);
+
+		if (_braille_register_console(newcon, &console_cmdline[i]))
 			return;
-		}
-#endif
+
 		if (newcon->setup &&
 		    newcon->setup(newcon, console_cmdline[i].options) != 0)
 			break;
@@ -2383,13 +2365,13 @@ EXPORT_SYMBOL(register_console);
 int unregister_console(struct console *console)
 {
         struct console *a, *b;
-	int res = 1;
+	int res;
 
-#ifdef CONFIG_A11Y_BRAILLE_CONSOLE
-	if (console->flags & CON_BRL)
-		return braille_unregister_console(console);
-#endif
+	res = _braille_unregister_console(console);
+	if (res)
+		return res;
 
+	res = 1;
 	console_lock();
 	if (console_drivers == console) {
 		console_drivers=console->next;
-- 
1.7.8.112.g3fd21

[PATCH V2 04/23] printk: Use pointer for console_cmdline indexing

[Joe Perches]

Make the code a bit more compact by always using a pointer
for the active console_cmdline.

Move overly indented code to correct indent level.

Signed-off-by: Joe Perches <joe@perches.com>
---
 kernel/printk/printk.c |   49 +++++++++++++++++++++++++----------------------
 1 files changed, 26 insertions(+), 23 deletions(-)

diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index df5b80f..099c439 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -1718,18 +1718,19 @@ static int __add_preferred_console(char *name, int idx, char *options,
 	 *	See if this tty is not yet registered, and
 	 *	if we have a slot free.
 	 */
-	for (i = 0; i < MAX_CMDLINECONSOLES && console_cmdline[i].name[0]; i++)
-		if (strcmp(console_cmdline[i].name, name) == 0 &&
-			  console_cmdline[i].index == idx) {
-				if (!brl_options)
-					selected_console = i;
-				return 0;
+	for (i = 0, c = console_cmdline;
+	     i < MAX_CMDLINECONSOLES && c->name[0];
+	     i++, c++) {
+		if (strcmp(c->name, name) == 0 && c->index == idx) {
+			if (!brl_options)
+				selected_console = i;
+			return 0;
 		}
+	}
 	if (i == MAX_CMDLINECONSOLES)
 		return -E2BIG;
 	if (!brl_options)
 		selected_console = i;
-	c = &console_cmdline[i];
 	strlcpy(c->name, name, sizeof(c->name));
 	c->options = options;
 	braille_set_options(c, brl_options);
@@ -1802,15 +1803,15 @@ int update_console_cmdline(char *name, int idx, char *name_new, int idx_new, cha
 	struct console_cmdline *c;
 	int i;
 
-	for (i = 0; i < MAX_CMDLINECONSOLES && console_cmdline[i].name[0]; i++)
-		if (strcmp(console_cmdline[i].name, name) == 0 &&
-			  console_cmdline[i].index == idx) {
-				c = &console_cmdline[i];
-				strlcpy(c->name, name_new, sizeof(c->name));
-				c->name[sizeof(c->name) - 1] = 0;
-				c->options = options;
-				c->index = idx_new;
-				return i;
+	for (i = 0, c = console_cmdline;
+	     i < MAX_CMDLINECONSOLES && c->name[0];
+	     i++, c++)
+		if (strcmp(c->name, name) == 0 && c->index == idx) {
+			strlcpy(c->name, name_new, sizeof(c->name));
+			c->name[sizeof(c->name) - 1] = 0;
+			c->options = options;
+			c->index = idx_new;
+			return i;
 		}
 	/* not found */
 	return -1;
@@ -2218,6 +2219,7 @@ void register_console(struct console *newcon)
 	int i;
 	unsigned long flags;
 	struct console *bcon = NULL;
+	struct console_cmdline *c;
 
 	/*
 	 * before we register a new CON_BOOT console, make sure we don't
@@ -2265,24 +2267,25 @@ void register_console(struct console *newcon)
 	 *	See if this console matches one we selected on
 	 *	the command line.
 	 */
-	for (i = 0; i < MAX_CMDLINECONSOLES && console_cmdline[i].name[0];
-			i++) {
-		if (strcmp(console_cmdline[i].name, newcon->name) != 0)
+	for (i = 0, c = console_cmdline;
+	     i < MAX_CMDLINECONSOLES && c->name[0];
+	     i++, c++) {
+		if (strcmp(c->name, newcon->name) != 0)
 			continue;
 		if (newcon->index >= 0 &&
-		    newcon->index != console_cmdline[i].index)
+		    newcon->index != c->index)
 			continue;
 		if (newcon->index < 0)
-			newcon->index = console_cmdline[i].index;
+			newcon->index = c->index;
 
-		if (_braille_register_console(newcon, &console_cmdline[i]))
+		if (_braille_register_console(newcon, c))
 			return;
 
 		if (newcon->setup &&
 		    newcon->setup(newcon, console_cmdline[i].options) != 0)
 			break;
 		newcon->flags |= CON_ENABLED;
-		newcon->index = console_cmdline[i].index;
+		newcon->index = c->index;
 		if (i == selected_console) {
 			newcon->flags |= CON_CONSDEV;
 			preferred_console = selected_console;
-- 
1.7.8.112.g3fd21

[PATCH V2 05/23] printk: rename struct log to struct printk_log

[Joe Perches]

Rename the struct to enable moving portions of
printk.c to separate files.

The rename changes output of /proc/vmcoreinfo.

Signed-off-by: Joe Perches <joe@perches.com>
---
 kernel/printk/printk.c |   80 ++++++++++++++++++++++++------------------------
 1 files changed, 40 insertions(+), 40 deletions(-)

diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 099c439..da2db46 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -172,7 +172,7 @@ static int console_may_schedule;
  *         67                           "g"
  *   0032     00 00 00                  padding to next message header
  *
- * The 'struct log' buffer header must never be directly exported to
+ * The 'struct printk_log' buffer header must never be directly exported to
  * userspace, it is a kernel-private implementation detail that might
  * need to be changed in the future, when the requirements change.
  *
@@ -194,7 +194,7 @@ enum log_flags {
 	LOG_CONT	= 8,	/* text is a fragment of a continuation line */
 };
 
-struct log {
+struct printk_log {
 	u64 ts_nsec;		/* timestamp in nanoseconds */
 	u16 len;		/* length of entire record */
 	u16 text_len;		/* length of text buffer */
@@ -241,7 +241,7 @@ static u32 clear_idx;
 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
 #define LOG_ALIGN 4
 #else
-#define LOG_ALIGN __alignof__(struct log)
+#define LOG_ALIGN __alignof__(struct printk_log)
 #endif
 #define __LOG_BUF_LEN (1 << CONFIG_LOG_BUF_SHIFT)
 static char __log_buf[__LOG_BUF_LEN] __aligned(LOG_ALIGN);
@@ -252,35 +252,35 @@ static u32 log_buf_len = __LOG_BUF_LEN;
 static volatile unsigned int logbuf_cpu = UINT_MAX;
 
 /* human readable text of the record */
-static char *log_text(const struct log *msg)
+static char *log_text(const struct printk_log *msg)
 {
-	return (char *)msg + sizeof(struct log);
+	return (char *)msg + sizeof(struct printk_log);
 }
 
 /* optional key/value pair dictionary attached to the record */
-static char *log_dict(const struct log *msg)
+static char *log_dict(const struct printk_log *msg)
 {
-	return (char *)msg + sizeof(struct log) + msg->text_len;
+	return (char *)msg + sizeof(struct printk_log) + msg->text_len;
 }
 
 /* get record by index; idx must point to valid msg */
-static struct log *log_from_idx(u32 idx)
+static struct printk_log *log_from_idx(u32 idx)
 {
-	struct log *msg = (struct log *)(log_buf + idx);
+	struct printk_log *msg = (struct printk_log *)(log_buf + idx);
 
 	/*
 	 * A length == 0 record is the end of buffer marker. Wrap around and
 	 * read the message at the start of the buffer.
 	 */
 	if (!msg->len)
-		return (struct log *)log_buf;
+		return (struct printk_log *)log_buf;
 	return msg;
 }
 
 /* get next record; idx must point to valid msg */
 static u32 log_next(u32 idx)
 {
-	struct log *msg = (struct log *)(log_buf + idx);
+	struct printk_log *msg = (struct printk_log *)(log_buf + idx);
 
 	/* length == 0 indicates the end of the buffer; wrap */
 	/*
@@ -289,7 +289,7 @@ static u32 log_next(u32 idx)
 	 * return the one after that.
 	 */
 	if (!msg->len) {
-		msg = (struct log *)log_buf;
+		msg = (struct printk_log *)log_buf;
 		return msg->len;
 	}
 	return idx + msg->len;
@@ -301,11 +301,11 @@ static void log_store(int facility, int level,
 		      const char *dict, u16 dict_len,
 		      const char *text, u16 text_len)
 {
-	struct log *msg;
+	struct printk_log *msg;
 	u32 size, pad_len;
 
 	/* number of '\0' padding bytes to next message */
-	size = sizeof(struct log) + text_len + dict_len;
+	size = sizeof(struct printk_log) + text_len + dict_len;
 	pad_len = (-size) & (LOG_ALIGN - 1);
 	size += pad_len;
 
@@ -317,7 +317,7 @@ static void log_store(int facility, int level,
 		else
 			free = log_first_idx - log_next_idx;
 
-		if (free > size + sizeof(struct log))
+		if (free > size + sizeof(struct printk_log))
 			break;
 
 		/* drop old messages until we have enough contiuous space */
@@ -325,18 +325,18 @@ static void log_store(int facility, int level,
 		log_first_seq++;
 	}
 
-	if (log_next_idx + size + sizeof(struct log) >= log_buf_len) {
+	if (log_next_idx + size + sizeof(struct printk_log) >= log_buf_len) {
 		/*
 		 * This message + an additional empty header does not fit
 		 * at the end of the buffer. Add an empty header with len == 0
 		 * to signify a wrap around.
 		 */
-		memset(log_buf + log_next_idx, 0, sizeof(struct log));
+		memset(log_buf + log_next_idx, 0, sizeof(struct printk_log));
 		log_next_idx = 0;
 	}
 
 	/* fill message */
-	msg = (struct log *)(log_buf + log_next_idx);
+	msg = (struct printk_log *)(log_buf + log_next_idx);
 	memcpy(log_text(msg), text, text_len);
 	msg->text_len = text_len;
 	memcpy(log_dict(msg), dict, dict_len);
@@ -349,7 +349,7 @@ static void log_store(int facility, int level,
 	else
 		msg->ts_nsec = local_clock();
 	memset(log_dict(msg) + dict_len, 0, pad_len);
-	msg->len = sizeof(struct log) + text_len + dict_len + pad_len;
+	msg->len = sizeof(struct printk_log) + text_len + dict_len + pad_len;
 
 	/* insert message */
 	log_next_idx += msg->len;
@@ -425,7 +425,7 @@ static ssize_t devkmsg_read(struct file *file, char __user *buf,
 			    size_t count, loff_t *ppos)
 {
 	struct devkmsg_user *user = file->private_data;
-	struct log *msg;
+	struct printk_log *msg;
 	u64 ts_usec;
 	size_t i;
 	char cont = '-';
@@ -668,14 +668,14 @@ void log_buf_kexec_setup(void)
 	VMCOREINFO_SYMBOL(log_first_idx);
 	VMCOREINFO_SYMBOL(log_next_idx);
 	/*
-	 * Export struct log size and field offsets. User space tools can
+	 * Export struct printk_log size and field offsets. User space tools can
 	 * parse it and detect any changes to structure down the line.
 	 */
-	VMCOREINFO_STRUCT_SIZE(log);
-	VMCOREINFO_OFFSET(log, ts_nsec);
-	VMCOREINFO_OFFSET(log, len);
-	VMCOREINFO_OFFSET(log, text_len);
-	VMCOREINFO_OFFSET(log, dict_len);
+	VMCOREINFO_STRUCT_SIZE(printk_log);
+	VMCOREINFO_OFFSET(printk_log, ts_nsec);
+	VMCOREINFO_OFFSET(printk_log, len);
+	VMCOREINFO_OFFSET(printk_log, text_len);
+	VMCOREINFO_OFFSET(printk_log, dict_len);
 }
 #endif
 
@@ -849,7 +849,7 @@ static size_t print_time(u64 ts, char *buf)
 		       (unsigned long)ts, rem_nsec / 1000);
 }
 
-static size_t print_prefix(const struct log *msg, bool syslog, char *buf)
+static size_t print_prefix(const struct printk_log *msg, bool syslog, char *buf)
 {
 	size_t len = 0;
 	unsigned int prefix = (msg->facility << 3) | msg->level;
@@ -872,7 +872,7 @@ static size_t print_prefix(const struct log *msg, bool syslog, char *buf)
 	return len;
 }
 
-static size_t msg_print_text(const struct log *msg, enum log_flags prev,
+static size_t msg_print_text(const struct printk_log *msg, enum log_flags prev,
 			     bool syslog, char *buf, size_t size)
 {
 	const char *text = log_text(msg);
@@ -934,7 +934,7 @@ static size_t msg_print_text(const struct log *msg, enum log_flags prev,
 static int syslog_print(char __user *buf, int size)
 {
 	char *text;
-	struct log *msg;
+	struct printk_log *msg;
 	int len = 0;
 
 	text = kmalloc(LOG_LINE_MAX + PREFIX_MAX, GFP_KERNEL);
@@ -1025,7 +1025,7 @@ static int syslog_print_all(char __user *buf, int size, bool clear)
 		idx = clear_idx;
 		prev = 0;
 		while (seq < log_next_seq) {
-			struct log *msg = log_from_idx(idx);
+			struct printk_log *msg = log_from_idx(idx);
 
 			len += msg_print_text(msg, prev, true, NULL, 0);
 			prev = msg->flags;
@@ -1038,7 +1038,7 @@ static int syslog_print_all(char __user *buf, int size, bool clear)
 		idx = clear_idx;
 		prev = 0;
 		while (len > size && seq < log_next_seq) {
-			struct log *msg = log_from_idx(idx);
+			struct printk_log *msg = log_from_idx(idx);
 
 			len -= msg_print_text(msg, prev, true, NULL, 0);
 			prev = msg->flags;
@@ -1052,7 +1052,7 @@ static int syslog_print_all(char __user *buf, int size, bool clear)
 		len = 0;
 		prev = 0;
 		while (len >= 0 && seq < next_seq) {
-			struct log *msg = log_from_idx(idx);
+			struct printk_log *msg = log_from_idx(idx);
 			int textlen;
 
 			textlen = msg_print_text(msg, prev, true, text,
@@ -1198,7 +1198,7 @@ int do_syslog(int type, char __user *buf, int len, bool from_file)
 
 			error = 0;
 			while (seq < log_next_seq) {
-				struct log *msg = log_from_idx(idx);
+				struct printk_log *msg = log_from_idx(idx);
 
 				error += msg_print_text(msg, prev, true, NULL, 0);
 				idx = log_next(idx);
@@ -1699,10 +1699,10 @@ static struct cont {
 	u8 level;
 	bool flushed:1;
 } cont;
-static struct log *log_from_idx(u32 idx) { return NULL; }
+static struct printk_log *log_from_idx(u32 idx) { return NULL; }
 static u32 log_next(u32 idx) { return 0; }
 static void call_console_drivers(int level, const char *text, size_t len) {}
-static size_t msg_print_text(const struct log *msg, enum log_flags prev,
+static size_t msg_print_text(const struct printk_log *msg, enum log_flags prev,
 			     bool syslog, char *buf, size_t size) { return 0; }
 static size_t cont_print_text(char *text, size_t size) { return 0; }
 
@@ -2025,7 +2025,7 @@ void console_unlock(void)
 	console_cont_flush(text, sizeof(text));
 again:
 	for (;;) {
-		struct log *msg;
+		struct printk_log *msg;
 		size_t len;
 		int level;
 
@@ -2601,7 +2601,7 @@ void kmsg_dump(enum kmsg_dump_reason reason)
 bool kmsg_dump_get_line_nolock(struct kmsg_dumper *dumper, bool syslog,
 			       char *line, size_t size, size_t *len)
 {
-	struct log *msg;
+	struct printk_log *msg;
 	size_t l = 0;
 	bool ret = false;
 
@@ -2713,7 +2713,7 @@ bool kmsg_dump_get_buffer(struct kmsg_dumper *dumper, bool syslog,
 	idx = dumper->cur_idx;
 	prev = 0;
 	while (seq < dumper->next_seq) {
-		struct log *msg = log_from_idx(idx);
+		struct printk_log *msg = log_from_idx(idx);
 
 		l += msg_print_text(msg, prev, true, NULL, 0);
 		idx = log_next(idx);
@@ -2726,7 +2726,7 @@ bool kmsg_dump_get_buffer(struct kmsg_dumper *dumper, bool syslog,
 	idx = dumper->cur_idx;
 	prev = 0;
 	while (l > size && seq < dumper->next_seq) {
-		struct log *msg = log_from_idx(idx);
+		struct printk_log *msg = log_from_idx(idx);
 
 		l -= msg_print_text(msg, prev, true, NULL, 0);
 		idx = log_next(idx);
@@ -2741,7 +2741,7 @@ bool kmsg_dump_get_buffer(struct kmsg_dumper *dumper, bool syslog,
 	l = 0;
 	prev = 0;
 	while (seq < dumper->next_seq) {
-		struct log *msg = log_from_idx(idx);
+		struct printk_log *msg = log_from_idx(idx);
 
 		l += msg_print_text(msg, prev, syslog, buf + l, size - l);
 		idx = log_next(idx);
-- 
1.7.8.112.g3fd21

[PATCH V2 06/23] printk: Rename log_buf and __LOG_BUF_LEN

[Joe Perches]

Make these generic names more specific to the printk
subsystem and allow these variables to become non-static.

Rename log_buf to printk_log_buf.
Rename __LOG_BUF_LEN define to __PRINTK_LOG_BUF_LEN.

Signed-off-by: Joe Perches <joe@perches.com>
---
 kernel/printk/printk.c |   76 ++++++++++++++++++++++++------------------------
 1 files changed, 38 insertions(+), 38 deletions(-)

diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index da2db46..c45afb1 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -243,10 +243,10 @@ static u32 clear_idx;
 #else
 #define LOG_ALIGN __alignof__(struct printk_log)
 #endif
-#define __LOG_BUF_LEN (1 << CONFIG_LOG_BUF_SHIFT)
-static char __log_buf[__LOG_BUF_LEN] __aligned(LOG_ALIGN);
-static char *log_buf = __log_buf;
-static u32 log_buf_len = __LOG_BUF_LEN;
+#define __PRINTK_LOG_BUF_LEN (1 << CONFIG_LOG_BUF_SHIFT)
+static char __printk_log_buf[__PRINTK_LOG_BUF_LEN] __aligned(LOG_ALIGN);
+static char *printk_log_buf = __printk_log_buf;
+static u32 printk_log_buf_len = __PRINTK_LOG_BUF_LEN;
 
 /* cpu currently holding logbuf_lock */
 static volatile unsigned int logbuf_cpu = UINT_MAX;
@@ -266,21 +266,21 @@ static char *log_dict(const struct printk_log *msg)
 /* get record by index; idx must point to valid msg */
 static struct printk_log *log_from_idx(u32 idx)
 {
-	struct printk_log *msg = (struct printk_log *)(log_buf + idx);
+	struct printk_log *msg = (struct printk_log *)(printk_log_buf + idx);
 
 	/*
 	 * A length == 0 record is the end of buffer marker. Wrap around and
 	 * read the message at the start of the buffer.
 	 */
 	if (!msg->len)
-		return (struct printk_log *)log_buf;
+		return (struct printk_log *)printk_log_buf;
 	return msg;
 }
 
 /* get next record; idx must point to valid msg */
 static u32 log_next(u32 idx)
 {
-	struct printk_log *msg = (struct printk_log *)(log_buf + idx);
+	struct printk_log *msg = (struct printk_log *)(printk_log_buf + idx);
 
 	/* length == 0 indicates the end of the buffer; wrap */
 	/*
@@ -289,7 +289,7 @@ static u32 log_next(u32 idx)
 	 * return the one after that.
 	 */
 	if (!msg->len) {
-		msg = (struct printk_log *)log_buf;
+		msg = (struct printk_log *)printk_log_buf;
 		return msg->len;
 	}
 	return idx + msg->len;
@@ -313,7 +313,7 @@ static void log_store(int facility, int level,
 		u32 free;
 
 		if (log_next_idx > log_first_idx)
-			free = max(log_buf_len - log_next_idx, log_first_idx);
+			free = max(printk_log_buf_len - log_next_idx, log_first_idx);
 		else
 			free = log_first_idx - log_next_idx;
 
@@ -325,18 +325,18 @@ static void log_store(int facility, int level,
 		log_first_seq++;
 	}
 
-	if (log_next_idx + size + sizeof(struct printk_log) >= log_buf_len) {
+	if (log_next_idx + size + sizeof(struct printk_log) >= printk_log_buf_len) {
 		/*
 		 * This message + an additional empty header does not fit
 		 * at the end of the buffer. Add an empty header with len == 0
 		 * to signify a wrap around.
 		 */
-		memset(log_buf + log_next_idx, 0, sizeof(struct printk_log));
+		memset(printk_log_buf + log_next_idx, 0, sizeof(struct printk_log));
 		log_next_idx = 0;
 	}
 
 	/* fill message */
-	msg = (struct printk_log *)(log_buf + log_next_idx);
+	msg = (struct printk_log *)(printk_log_buf + log_next_idx);
 	memcpy(log_text(msg), text, text_len);
 	msg->text_len = text_len;
 	memcpy(log_dict(msg), dict, dict_len);
@@ -663,8 +663,8 @@ const struct file_operations kmsg_fops = {
  */
 void log_buf_kexec_setup(void)
 {
-	VMCOREINFO_SYMBOL(log_buf);
-	VMCOREINFO_SYMBOL(log_buf_len);
+	VMCOREINFO_SYMBOL(printk_log_buf);
+	VMCOREINFO_SYMBOL(printk_log_buf_len);
 	VMCOREINFO_SYMBOL(log_first_idx);
 	VMCOREINFO_SYMBOL(log_next_idx);
 	/*
@@ -679,60 +679,60 @@ void log_buf_kexec_setup(void)
 }
 #endif
 
-/* requested log_buf_len from kernel cmdline */
-static unsigned long __initdata new_log_buf_len;
+/* requested printk_log_buf_len from kernel cmdline */
+static unsigned long __initdata new_printk_log_buf_len;
 
-/* save requested log_buf_len since it's too early to process it */
-static int __init log_buf_len_setup(char *str)
+/* save requested printk_log_buf_len since it's too early to process it */
+static int __init printk_log_buf_len_setup(char *str)
 {
 	unsigned size = memparse(str, &str);
 
 	if (size)
 		size = roundup_pow_of_two(size);
-	if (size > log_buf_len)
-		new_log_buf_len = size;
+	if (size > printk_log_buf_len)
+		new_printk_log_buf_len = size;
 
 	return 0;
 }
-early_param("log_buf_len", log_buf_len_setup);
+early_param("log_buf_len", printk_log_buf_len_setup);
 
 void __init setup_log_buf(int early)
 {
 	unsigned long flags;
-	char *new_log_buf;
+	char *new_printk_log_buf;
 	int free;
 
-	if (!new_log_buf_len)
+	if (!new_printk_log_buf_len)
 		return;
 
 	if (early) {
 		unsigned long mem;
 
-		mem = memblock_alloc(new_log_buf_len, PAGE_SIZE);
+		mem = memblock_alloc(new_printk_log_buf_len, PAGE_SIZE);
 		if (!mem)
 			return;
-		new_log_buf = __va(mem);
+		new_printk_log_buf = __va(mem);
 	} else {
-		new_log_buf = alloc_bootmem_nopanic(new_log_buf_len);
+		new_printk_log_buf = alloc_bootmem_nopanic(new_printk_log_buf_len);
 	}
 
-	if (unlikely(!new_log_buf)) {
-		pr_err("log_buf_len: %ld bytes not available\n",
-			new_log_buf_len);
+	if (unlikely(!new_printk_log_buf)) {
+		pr_err("printk_log_buf_len: %ld bytes not available\n",
+			new_printk_log_buf_len);
 		return;
 	}
 
 	raw_spin_lock_irqsave(&logbuf_lock, flags);
-	log_buf_len = new_log_buf_len;
-	log_buf = new_log_buf;
-	new_log_buf_len = 0;
-	free = __LOG_BUF_LEN - log_next_idx;
-	memcpy(log_buf, __log_buf, __LOG_BUF_LEN);
+	printk_log_buf_len = new_printk_log_buf_len;
+	printk_log_buf = new_printk_log_buf;
+	new_printk_log_buf_len = 0;
+	free = __PRINTK_LOG_BUF_LEN - log_next_idx;
+	memcpy(printk_log_buf, __printk_log_buf, __PRINTK_LOG_BUF_LEN);
 	raw_spin_unlock_irqrestore(&logbuf_lock, flags);
 
-	pr_info("log_buf_len: %d\n", log_buf_len);
+	pr_info("printk_log_buf_len: %d\n", printk_log_buf_len);
 	pr_info("early log buf free: %d(%d%%)\n",
-		free, (free * 100) / __LOG_BUF_LEN);
+		free, (free * 100) / __PRINTK_LOG_BUF_LEN);
 }
 
 #ifdef CONFIG_BOOT_PRINTK_DELAY
@@ -1211,7 +1211,7 @@ int do_syslog(int type, char __user *buf, int len, bool from_file)
 		break;
 	/* Size of the log buffer */
 	case SYSLOG_ACTION_SIZE_BUFFER:
-		error = log_buf_len;
+		error = printk_log_buf_len;
 		break;
 	default:
 		error = -EINVAL;
@@ -1243,7 +1243,7 @@ MODULE_PARM_DESC(ignore_loglevel, "ignore loglevel setting, to"
 
 /*
  * Call the console drivers, asking them to write out
- * log_buf[start] to log_buf[end - 1].
+ * printk_log_buf[start] to printk_log_buf[end - 1].
  * The console_lock must be held.
  */
 static void call_console_drivers(int level, const char *text, size_t len)
-- 
1.7.8.112.g3fd21

[PATCH V2 07/23] printk: Rename log_first and log_next variables

[Joe Perches]

Make these generic names more specific to the printk
subsystem and allow these variables to become non-static.

Rename log_first_idx to printk_log_first_idx.
Rename log_first_seq to printk_log_first_seq.
Rename log_next_idx to printk_log_next_idx.
Rename log_next_seq to printk_log_next_seq.

Signed-off-by: Joe Perches <joe@perches.com>
---
 kernel/printk/printk.c |  150 ++++++++++++++++++++++++------------------------
 1 files changed, 75 insertions(+), 75 deletions(-)

diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index c45afb1..602a1ab 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -218,12 +218,12 @@ static enum log_flags syslog_prev;
 static size_t syslog_partial;
 
 /* index and sequence number of the first record stored in the buffer */
-static u64 log_first_seq;
-static u32 log_first_idx;
+static u64 printk_log_first_seq;
+static u32 printk_log_first_idx;
 
 /* index and sequence number of the next record to store in the buffer */
-static u64 log_next_seq;
-static u32 log_next_idx;
+static u64 printk_log_next_seq;
+static u32 printk_log_next_idx;
 
 /* the next printk record to write to the console */
 static u64 console_seq;
@@ -309,34 +309,34 @@ static void log_store(int facility, int level,
 	pad_len = (-size) & (LOG_ALIGN - 1);
 	size += pad_len;
 
-	while (log_first_seq < log_next_seq) {
+	while (printk_log_first_seq < printk_log_next_seq) {
 		u32 free;
 
-		if (log_next_idx > log_first_idx)
-			free = max(printk_log_buf_len - log_next_idx, log_first_idx);
+		if (printk_log_next_idx > printk_log_first_idx)
+			free = max(printk_log_buf_len - printk_log_next_idx, printk_log_first_idx);
 		else
-			free = log_first_idx - log_next_idx;
+			free = printk_log_first_idx - printk_log_next_idx;
 
 		if (free > size + sizeof(struct printk_log))
 			break;
 
 		/* drop old messages until we have enough contiuous space */
-		log_first_idx = log_next(log_first_idx);
-		log_first_seq++;
+		printk_log_first_idx = log_next(printk_log_first_idx);
+		printk_log_first_seq++;
 	}
 
-	if (log_next_idx + size + sizeof(struct printk_log) >= printk_log_buf_len) {
+	if (printk_log_next_idx + size + sizeof(struct printk_log) >= printk_log_buf_len) {
 		/*
 		 * This message + an additional empty header does not fit
 		 * at the end of the buffer. Add an empty header with len == 0
 		 * to signify a wrap around.
 		 */
-		memset(printk_log_buf + log_next_idx, 0, sizeof(struct printk_log));
-		log_next_idx = 0;
+		memset(printk_log_buf + printk_log_next_idx, 0, sizeof(struct printk_log));
+		printk_log_next_idx = 0;
 	}
 
 	/* fill message */
-	msg = (struct printk_log *)(printk_log_buf + log_next_idx);
+	msg = (struct printk_log *)(printk_log_buf + printk_log_next_idx);
 	memcpy(log_text(msg), text, text_len);
 	msg->text_len = text_len;
 	memcpy(log_dict(msg), dict, dict_len);
@@ -352,8 +352,8 @@ static void log_store(int facility, int level,
 	msg->len = sizeof(struct printk_log) + text_len + dict_len + pad_len;
 
 	/* insert message */
-	log_next_idx += msg->len;
-	log_next_seq++;
+	printk_log_next_idx += msg->len;
+	printk_log_next_seq++;
 }
 
 /* /dev/kmsg - userspace message inject/listen interface */
@@ -439,7 +439,7 @@ static ssize_t devkmsg_read(struct file *file, char __user *buf,
 	if (ret)
 		return ret;
 	raw_spin_lock_irq(&logbuf_lock);
-	while (user->seq == log_next_seq) {
+	while (user->seq == printk_log_next_seq) {
 		if (file->f_flags & O_NONBLOCK) {
 			ret = -EAGAIN;
 			raw_spin_unlock_irq(&logbuf_lock);
@@ -448,16 +448,16 @@ static ssize_t devkmsg_read(struct file *file, char __user *buf,
 
 		raw_spin_unlock_irq(&logbuf_lock);
 		ret = wait_event_interruptible(log_wait,
-					       user->seq != log_next_seq);
+					       user->seq != printk_log_next_seq);
 		if (ret)
 			goto out;
 		raw_spin_lock_irq(&logbuf_lock);
 	}
 
-	if (user->seq < log_first_seq) {
+	if (user->seq < printk_log_first_seq) {
 		/* our last seen message is gone, return error and reset */
-		user->idx = log_first_idx;
-		user->seq = log_first_seq;
+		user->idx = printk_log_first_idx;
+		user->seq = printk_log_first_seq;
 		ret = -EPIPE;
 		raw_spin_unlock_irq(&logbuf_lock);
 		goto out;
@@ -557,8 +557,8 @@ static loff_t devkmsg_llseek(struct file *file, loff_t offset, int whence)
 	switch (whence) {
 	case SEEK_SET:
 		/* the first record */
-		user->idx = log_first_idx;
-		user->seq = log_first_seq;
+		user->idx = printk_log_first_idx;
+		user->seq = printk_log_first_seq;
 		break;
 	case SEEK_DATA:
 		/*
@@ -571,8 +571,8 @@ static loff_t devkmsg_llseek(struct file *file, loff_t offset, int whence)
 		break;
 	case SEEK_END:
 		/* after the last record */
-		user->idx = log_next_idx;
-		user->seq = log_next_seq;
+		user->idx = printk_log_next_idx;
+		user->seq = printk_log_next_seq;
 		break;
 	default:
 		ret = -EINVAL;
@@ -592,9 +592,9 @@ static unsigned int devkmsg_poll(struct file *file, poll_table *wait)
 	poll_wait(file, &log_wait, wait);
 
 	raw_spin_lock_irq(&logbuf_lock);
-	if (user->seq < log_next_seq) {
+	if (user->seq < printk_log_next_seq) {
 		/* return error when data has vanished underneath us */
-		if (user->seq < log_first_seq)
+		if (user->seq < printk_log_first_seq)
 			ret = POLLIN|POLLRDNORM|POLLERR|POLLPRI;
 		ret = POLLIN|POLLRDNORM;
 	}
@@ -623,8 +623,8 @@ static int devkmsg_open(struct inode *inode, struct file *file)
 	mutex_init(&user->lock);
 
 	raw_spin_lock_irq(&logbuf_lock);
-	user->idx = log_first_idx;
-	user->seq = log_first_seq;
+	user->idx = printk_log_first_idx;
+	user->seq = printk_log_first_seq;
 	raw_spin_unlock_irq(&logbuf_lock);
 
 	file->private_data = user;
@@ -665,8 +665,8 @@ void log_buf_kexec_setup(void)
 {
 	VMCOREINFO_SYMBOL(printk_log_buf);
 	VMCOREINFO_SYMBOL(printk_log_buf_len);
-	VMCOREINFO_SYMBOL(log_first_idx);
-	VMCOREINFO_SYMBOL(log_next_idx);
+	VMCOREINFO_SYMBOL(printk_log_first_idx);
+	VMCOREINFO_SYMBOL(printk_log_next_idx);
 	/*
 	 * Export struct printk_log size and field offsets. User space tools can
 	 * parse it and detect any changes to structure down the line.
@@ -726,7 +726,7 @@ void __init setup_log_buf(int early)
 	printk_log_buf_len = new_printk_log_buf_len;
 	printk_log_buf = new_printk_log_buf;
 	new_printk_log_buf_len = 0;
-	free = __PRINTK_LOG_BUF_LEN - log_next_idx;
+	free = __PRINTK_LOG_BUF_LEN - printk_log_next_idx;
 	memcpy(printk_log_buf, __printk_log_buf, __PRINTK_LOG_BUF_LEN);
 	raw_spin_unlock_irqrestore(&logbuf_lock, flags);
 
@@ -946,14 +946,14 @@ static int syslog_print(char __user *buf, int size)
 		size_t skip;
 
 		raw_spin_lock_irq(&logbuf_lock);
-		if (syslog_seq < log_first_seq) {
+		if (syslog_seq < printk_log_first_seq) {
 			/* messages are gone, move to first one */
-			syslog_seq = log_first_seq;
-			syslog_idx = log_first_idx;
+			syslog_seq = printk_log_first_seq;
+			syslog_idx = printk_log_first_idx;
 			syslog_prev = 0;
 			syslog_partial = 0;
 		}
-		if (syslog_seq == log_next_seq) {
+		if (syslog_seq == printk_log_next_seq) {
 			raw_spin_unlock_irq(&logbuf_lock);
 			break;
 		}
@@ -1011,10 +1011,10 @@ static int syslog_print_all(char __user *buf, int size, bool clear)
 		u32 idx;
 		enum log_flags prev;
 
-		if (clear_seq < log_first_seq) {
+		if (clear_seq < printk_log_first_seq) {
 			/* messages are gone, move to first available one */
-			clear_seq = log_first_seq;
-			clear_idx = log_first_idx;
+			clear_seq = printk_log_first_seq;
+			clear_idx = printk_log_first_idx;
 		}
 
 		/*
@@ -1024,7 +1024,7 @@ static int syslog_print_all(char __user *buf, int size, bool clear)
 		seq = clear_seq;
 		idx = clear_idx;
 		prev = 0;
-		while (seq < log_next_seq) {
+		while (seq < printk_log_next_seq) {
 			struct printk_log *msg = log_from_idx(idx);
 
 			len += msg_print_text(msg, prev, true, NULL, 0);
@@ -1037,7 +1037,7 @@ static int syslog_print_all(char __user *buf, int size, bool clear)
 		seq = clear_seq;
 		idx = clear_idx;
 		prev = 0;
-		while (len > size && seq < log_next_seq) {
+		while (len > size && seq < printk_log_next_seq) {
 			struct printk_log *msg = log_from_idx(idx);
 
 			len -= msg_print_text(msg, prev, true, NULL, 0);
@@ -1047,7 +1047,7 @@ static int syslog_print_all(char __user *buf, int size, bool clear)
 		}
 
 		/* last message fitting into this dump */
-		next_seq = log_next_seq;
+		next_seq = printk_log_next_seq;
 
 		len = 0;
 		prev = 0;
@@ -1072,18 +1072,18 @@ static int syslog_print_all(char __user *buf, int size, bool clear)
 				len += textlen;
 			raw_spin_lock_irq(&logbuf_lock);
 
-			if (seq < log_first_seq) {
+			if (seq < printk_log_first_seq) {
 				/* messages are gone, move to next one */
-				seq = log_first_seq;
-				idx = log_first_idx;
+				seq = printk_log_first_seq;
+				idx = printk_log_first_idx;
 				prev = 0;
 			}
 		}
 	}
 
 	if (clear) {
-		clear_seq = log_next_seq;
-		clear_idx = log_next_idx;
+		clear_seq = printk_log_next_seq;
+		clear_idx = printk_log_next_idx;
 	}
 	raw_spin_unlock_irq(&logbuf_lock);
 
@@ -1122,7 +1122,7 @@ int do_syslog(int type, char __user *buf, int len, bool from_file)
 			goto out;
 		}
 		error = wait_event_interruptible(log_wait,
-						 syslog_seq != log_next_seq);
+						 syslog_seq != printk_log_next_seq);
 		if (error)
 			goto out;
 		error = syslog_print(buf, len);
@@ -1177,10 +1177,10 @@ int do_syslog(int type, char __user *buf, int len, bool from_file)
 	/* Number of chars in the log buffer */
 	case SYSLOG_ACTION_SIZE_UNREAD:
 		raw_spin_lock_irq(&logbuf_lock);
-		if (syslog_seq < log_first_seq) {
+		if (syslog_seq < printk_log_first_seq) {
 			/* messages are gone, move to first one */
-			syslog_seq = log_first_seq;
-			syslog_idx = log_first_idx;
+			syslog_seq = printk_log_first_seq;
+			syslog_idx = printk_log_first_idx;
 			syslog_prev = 0;
 			syslog_partial = 0;
 		}
@@ -1190,14 +1190,14 @@ int do_syslog(int type, char __user *buf, int len, bool from_file)
 			 * for pending data, not the size; return the count of
 			 * records, not the length.
 			 */
-			error = log_next_idx - syslog_idx;
+			error = printk_log_next_idx - syslog_idx;
 		} else {
 			u64 seq = syslog_seq;
 			u32 idx = syslog_idx;
 			enum log_flags prev = syslog_prev;
 
 			error = 0;
-			while (seq < log_next_seq) {
+			while (seq < printk_log_next_seq) {
 				struct printk_log *msg = log_from_idx(idx);
 
 				error += msg_print_text(msg, prev, true, NULL, 0);
@@ -1689,9 +1689,9 @@ static u32 syslog_idx;
 static u64 console_seq;
 static u32 console_idx;
 static enum log_flags syslog_prev;
-static u64 log_first_seq;
-static u32 log_first_idx;
-static u64 log_next_seq;
+static u64 printk_log_first_seq;
+static u32 printk_log_first_idx;
+static u64 printk_log_next_seq;
 static enum log_flags console_prev;
 static struct cont {
 	size_t len;
@@ -1978,7 +1978,7 @@ static void console_cont_flush(char *text, size_t size)
 	 * busy. The earlier ones need to be printed before this one, we
 	 * did not flush any fragment so far, so just let it queue up.
 	 */
-	if (console_seq < log_next_seq && !cont.cons)
+	if (console_seq < printk_log_next_seq && !cont.cons)
 		goto out;
 
 	len = cont_print_text(text, size);
@@ -2030,19 +2030,19 @@ again:
 		int level;
 
 		raw_spin_lock_irqsave(&logbuf_lock, flags);
-		if (seen_seq != log_next_seq) {
+		if (seen_seq != printk_log_next_seq) {
 			wake_klogd = true;
-			seen_seq = log_next_seq;
+			seen_seq = printk_log_next_seq;
 		}
 
-		if (console_seq < log_first_seq) {
+		if (console_seq < printk_log_first_seq) {
 			/* messages are gone, move to first one */
-			console_seq = log_first_seq;
-			console_idx = log_first_idx;
+			console_seq = printk_log_first_seq;
+			console_idx = printk_log_first_idx;
 			console_prev = 0;
 		}
 skip:
-		if (console_seq == log_next_seq)
+		if (console_seq == printk_log_next_seq)
 			break;
 
 		msg = log_from_idx(console_idx);
@@ -2093,7 +2093,7 @@ skip:
 	 * flush, no worries.
 	 */
 	raw_spin_lock(&logbuf_lock);
-	retry = console_seq != log_next_seq;
+	retry = console_seq != printk_log_next_seq;
 	raw_spin_unlock_irqrestore(&logbuf_lock, flags);
 
 	if (retry && console_trylock())
@@ -2566,8 +2566,8 @@ void kmsg_dump(enum kmsg_dump_reason reason)
 		raw_spin_lock_irqsave(&logbuf_lock, flags);
 		dumper->cur_seq = clear_seq;
 		dumper->cur_idx = clear_idx;
-		dumper->next_seq = log_next_seq;
-		dumper->next_idx = log_next_idx;
+		dumper->next_seq = printk_log_next_seq;
+		dumper->next_idx = printk_log_next_idx;
 		raw_spin_unlock_irqrestore(&logbuf_lock, flags);
 
 		/* invoke dumper which will iterate over records */
@@ -2608,14 +2608,14 @@ bool kmsg_dump_get_line_nolock(struct kmsg_dumper *dumper, bool syslog,
 	if (!dumper->active)
 		goto out;
 
-	if (dumper->cur_seq < log_first_seq) {
+	if (dumper->cur_seq < printk_log_first_seq) {
 		/* messages are gone, move to first available one */
-		dumper->cur_seq = log_first_seq;
-		dumper->cur_idx = log_first_idx;
+		dumper->cur_seq = printk_log_first_seq;
+		dumper->cur_idx = printk_log_first_idx;
 	}
 
 	/* last entry */
-	if (dumper->cur_seq >= log_next_seq)
+	if (dumper->cur_seq >= printk_log_next_seq)
 		goto out;
 
 	msg = log_from_idx(dumper->cur_idx);
@@ -2696,10 +2696,10 @@ bool kmsg_dump_get_buffer(struct kmsg_dumper *dumper, bool syslog,
 		goto out;
 
 	raw_spin_lock_irqsave(&logbuf_lock, flags);
-	if (dumper->cur_seq < log_first_seq) {
+	if (dumper->cur_seq < printk_log_first_seq) {
 		/* messages are gone, move to first available one */
-		dumper->cur_seq = log_first_seq;
-		dumper->cur_idx = log_first_idx;
+		dumper->cur_seq = printk_log_first_seq;
+		dumper->cur_idx = printk_log_first_idx;
 	}
 
 	/* last entry */
@@ -2774,8 +2774,8 @@ void kmsg_dump_rewind_nolock(struct kmsg_dumper *dumper)
 {
 	dumper->cur_seq = clear_seq;
 	dumper->cur_idx = clear_idx;
-	dumper->next_seq = log_next_seq;
-	dumper->next_idx = log_next_idx;
+	dumper->next_seq = printk_log_next_seq;
+	dumper->next_idx = printk_log_next_idx;
 }
 
 /**
-- 
1.7.8.112.g3fd21

[PATCH V2 08/23] printk: Rename log_<foo> variables and functions

[Joe Perches]

Make these generic names more specific to the printk
subsystem and allow these variables and functions to
become non-static.

Rename log_text to printk_log_text.
Rename log_dict to printk_log_dict.
Rename log_from_idx to printk_log_from_idx.
Rename log_next to printk_log_next.
Rename log_store to printk_log_store.

Signed-off-by: Joe Perches <joe@perches.com>
---
 kernel/printk/printk.c |  100 ++++++++++++++++++++++++------------------------
 1 files changed, 50 insertions(+), 50 deletions(-)

diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 602a1ab..992c064 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -252,19 +252,19 @@ static u32 printk_log_buf_len = __PRINTK_LOG_BUF_LEN;
 static volatile unsigned int logbuf_cpu = UINT_MAX;
 
 /* human readable text of the record */
-static char *log_text(const struct printk_log *msg)
+static char *printk_log_text(const struct printk_log *msg)
 {
 	return (char *)msg + sizeof(struct printk_log);
 }
 
 /* optional key/value pair dictionary attached to the record */
-static char *log_dict(const struct printk_log *msg)
+static char *printk_log_dict(const struct printk_log *msg)
 {
 	return (char *)msg + sizeof(struct printk_log) + msg->text_len;
 }
 
 /* get record by index; idx must point to valid msg */
-static struct printk_log *log_from_idx(u32 idx)
+static struct printk_log *printk_log_from_idx(u32 idx)
 {
 	struct printk_log *msg = (struct printk_log *)(printk_log_buf + idx);
 
@@ -278,7 +278,7 @@ static struct printk_log *log_from_idx(u32 idx)
 }
 
 /* get next record; idx must point to valid msg */
-static u32 log_next(u32 idx)
+static u32 printk_log_next(u32 idx)
 {
 	struct printk_log *msg = (struct printk_log *)(printk_log_buf + idx);
 
@@ -296,10 +296,10 @@ static u32 log_next(u32 idx)
 }
 
 /* insert record into the buffer, discard old ones, update heads */
-static void log_store(int facility, int level,
-		      enum log_flags flags, u64 ts_nsec,
-		      const char *dict, u16 dict_len,
-		      const char *text, u16 text_len)
+static void printk_log_store(int facility, int level,
+			     enum log_flags flags, u64 ts_nsec,
+			     const char *dict, u16 dict_len,
+			     const char *text, u16 text_len)
 {
 	struct printk_log *msg;
 	u32 size, pad_len;
@@ -321,7 +321,7 @@ static void log_store(int facility, int level,
 			break;
 
 		/* drop old messages until we have enough contiuous space */
-		printk_log_first_idx = log_next(printk_log_first_idx);
+		printk_log_first_idx = printk_log_next(printk_log_first_idx);
 		printk_log_first_seq++;
 	}
 
@@ -337,9 +337,9 @@ static void log_store(int facility, int level,
 
 	/* fill message */
 	msg = (struct printk_log *)(printk_log_buf + printk_log_next_idx);
-	memcpy(log_text(msg), text, text_len);
+	memcpy(printk_log_text(msg), text, text_len);
 	msg->text_len = text_len;
-	memcpy(log_dict(msg), dict, dict_len);
+	memcpy(printk_log_dict(msg), dict, dict_len);
 	msg->dict_len = dict_len;
 	msg->facility = facility;
 	msg->level = level & 7;
@@ -348,7 +348,7 @@ static void log_store(int facility, int level,
 		msg->ts_nsec = ts_nsec;
 	else
 		msg->ts_nsec = local_clock();
-	memset(log_dict(msg) + dict_len, 0, pad_len);
+	memset(printk_log_dict(msg) + dict_len, 0, pad_len);
 	msg->len = sizeof(struct printk_log) + text_len + dict_len + pad_len;
 
 	/* insert message */
@@ -463,7 +463,7 @@ static ssize_t devkmsg_read(struct file *file, char __user *buf,
 		goto out;
 	}
 
-	msg = log_from_idx(user->idx);
+	msg = printk_log_from_idx(user->idx);
 	ts_usec = msg->ts_nsec;
 	do_div(ts_usec, 1000);
 
@@ -488,7 +488,7 @@ static ssize_t devkmsg_read(struct file *file, char __user *buf,
 
 	/* escape non-printable characters */
 	for (i = 0; i < msg->text_len; i++) {
-		unsigned char c = log_text(msg)[i];
+		unsigned char c = printk_log_text(msg)[i];
 
 		if (c < ' ' || c >= 127 || c == '\\')
 			len += sprintf(user->buf + len, "\\x%02x", c);
@@ -501,7 +501,7 @@ static ssize_t devkmsg_read(struct file *file, char __user *buf,
 		bool line = true;
 
 		for (i = 0; i < msg->dict_len; i++) {
-			unsigned char c = log_dict(msg)[i];
+			unsigned char c = printk_log_dict(msg)[i];
 
 			if (line) {
 				user->buf[len++] = ' ';
@@ -524,7 +524,7 @@ static ssize_t devkmsg_read(struct file *file, char __user *buf,
 		user->buf[len++] = '\n';
 	}
 
-	user->idx = log_next(user->idx);
+	user->idx = printk_log_next(user->idx);
 	user->seq++;
 	raw_spin_unlock_irq(&logbuf_lock);
 
@@ -875,7 +875,7 @@ static size_t print_prefix(const struct printk_log *msg, bool syslog, char *buf)
 static size_t msg_print_text(const struct printk_log *msg, enum log_flags prev,
 			     bool syslog, char *buf, size_t size)
 {
-	const char *text = log_text(msg);
+	const char *text = printk_log_text(msg);
 	size_t text_size = msg->text_len;
 	bool prefix = true;
 	bool newline = true;
@@ -959,12 +959,12 @@ static int syslog_print(char __user *buf, int size)
 		}
 
 		skip = syslog_partial;
-		msg = log_from_idx(syslog_idx);
+		msg = printk_log_from_idx(syslog_idx);
 		n = msg_print_text(msg, syslog_prev, true, text,
 				   LOG_LINE_MAX + PREFIX_MAX);
 		if (n - syslog_partial <= size) {
 			/* message fits into buffer, move forward */
-			syslog_idx = log_next(syslog_idx);
+			syslog_idx = printk_log_next(syslog_idx);
 			syslog_seq++;
 			syslog_prev = msg->flags;
 			n -= syslog_partial;
@@ -1025,11 +1025,11 @@ static int syslog_print_all(char __user *buf, int size, bool clear)
 		idx = clear_idx;
 		prev = 0;
 		while (seq < printk_log_next_seq) {
-			struct printk_log *msg = log_from_idx(idx);
+			struct printk_log *msg = printk_log_from_idx(idx);
 
 			len += msg_print_text(msg, prev, true, NULL, 0);
 			prev = msg->flags;
-			idx = log_next(idx);
+			idx = printk_log_next(idx);
 			seq++;
 		}
 
@@ -1038,11 +1038,11 @@ static int syslog_print_all(char __user *buf, int size, bool clear)
 		idx = clear_idx;
 		prev = 0;
 		while (len > size && seq < printk_log_next_seq) {
-			struct printk_log *msg = log_from_idx(idx);
+			struct printk_log *msg = printk_log_from_idx(idx);
 
 			len -= msg_print_text(msg, prev, true, NULL, 0);
 			prev = msg->flags;
-			idx = log_next(idx);
+			idx = printk_log_next(idx);
 			seq++;
 		}
 
@@ -1052,7 +1052,7 @@ static int syslog_print_all(char __user *buf, int size, bool clear)
 		len = 0;
 		prev = 0;
 		while (len >= 0 && seq < next_seq) {
-			struct printk_log *msg = log_from_idx(idx);
+			struct printk_log *msg = printk_log_from_idx(idx);
 			int textlen;
 
 			textlen = msg_print_text(msg, prev, true, text,
@@ -1061,7 +1061,7 @@ static int syslog_print_all(char __user *buf, int size, bool clear)
 				len = textlen;
 				break;
 			}
-			idx = log_next(idx);
+			idx = printk_log_next(idx);
 			seq++;
 			prev = msg->flags;
 
@@ -1198,10 +1198,10 @@ int do_syslog(int type, char __user *buf, int len, bool from_file)
 
 			error = 0;
 			while (seq < printk_log_next_seq) {
-				struct printk_log *msg = log_from_idx(idx);
+				struct printk_log *msg = printk_log_from_idx(idx);
 
 				error += msg_print_text(msg, prev, true, NULL, 0);
-				idx = log_next(idx);
+				idx = printk_log_next(idx);
 				seq++;
 				prev = msg->flags;
 			}
@@ -1400,8 +1400,8 @@ static void cont_flush(enum log_flags flags)
 		 * console; wait for the console to pick up the rest of the
 		 * line. LOG_NOCONS suppresses a duplicated output.
 		 */
-		log_store(cont.facility, cont.level, flags | LOG_NOCONS,
-			  cont.ts_nsec, NULL, 0, cont.buf, cont.len);
+		printk_log_store(cont.facility, cont.level, flags | LOG_NOCONS,
+				 cont.ts_nsec, NULL, 0, cont.buf, cont.len);
 		cont.flags = flags;
 		cont.flushed = true;
 	} else {
@@ -1409,8 +1409,8 @@ static void cont_flush(enum log_flags flags)
 		 * If no fragment of this line ever reached the console,
 		 * just submit it to the store and free the buffer.
 		 */
-		log_store(cont.facility, cont.level, flags, 0,
-			  NULL, 0, cont.buf, cont.len);
+		printk_log_store(cont.facility, cont.level, flags, 0,
+				 NULL, 0, cont.buf, cont.len);
 		cont.len = 0;
 	}
 }
@@ -1522,8 +1522,8 @@ asmlinkage int vprintk_emit(int facility, int level,
 		recursion_bug = 0;
 		printed_len += strlen(recursion_msg);
 		/* emit KERN_CRIT message */
-		log_store(0, 2, LOG_PREFIX|LOG_NEWLINE, 0,
-			  NULL, 0, recursion_msg, printed_len);
+		printk_log_store(0, 2, LOG_PREFIX|LOG_NEWLINE, 0,
+				 NULL, 0, recursion_msg, printed_len);
 	}
 
 	/*
@@ -1574,8 +1574,8 @@ asmlinkage int vprintk_emit(int facility, int level,
 
 		/* buffer line if possible, otherwise store it right away */
 		if (!cont_add(facility, level, text, text_len))
-			log_store(facility, level, lflags | LOG_CONT, 0,
-				  dict, dictlen, text, text_len);
+			printk_log_store(facility, level, lflags | LOG_CONT, 0,
+					 dict, dictlen, text, text_len);
 	} else {
 		bool stored = false;
 
@@ -1592,8 +1592,8 @@ asmlinkage int vprintk_emit(int facility, int level,
 		}
 
 		if (!stored)
-			log_store(facility, level, lflags, 0,
-				  dict, dictlen, text, text_len);
+			printk_log_store(facility, level, lflags, 0,
+					 dict, dictlen, text, text_len);
 	}
 	printed_len += text_len;
 
@@ -1699,8 +1699,8 @@ static struct cont {
 	u8 level;
 	bool flushed:1;
 } cont;
-static struct printk_log *log_from_idx(u32 idx) { return NULL; }
-static u32 log_next(u32 idx) { return 0; }
+static struct printk_log *printk_log_from_idx(u32 idx) { return NULL; }
+static u32 printk_log_next(u32 idx) { return 0; }
 static void call_console_drivers(int level, const char *text, size_t len) {}
 static size_t msg_print_text(const struct printk_log *msg, enum log_flags prev,
 			     bool syslog, char *buf, size_t size) { return 0; }
@@ -2045,13 +2045,13 @@ skip:
 		if (console_seq == printk_log_next_seq)
 			break;
 
-		msg = log_from_idx(console_idx);
+		msg = printk_log_from_idx(console_idx);
 		if (msg->flags & LOG_NOCONS) {
 			/*
 			 * Skip record we have buffered and already printed
 			 * directly to the console when we received it.
 			 */
-			console_idx = log_next(console_idx);
+			console_idx = printk_log_next(console_idx);
 			console_seq++;
 			/*
 			 * We will get here again when we register a new
@@ -2066,7 +2066,7 @@ skip:
 		level = msg->level;
 		len = msg_print_text(msg, console_prev, false,
 				     text, sizeof(text));
-		console_idx = log_next(console_idx);
+		console_idx = printk_log_next(console_idx);
 		console_seq++;
 		console_prev = msg->flags;
 		raw_spin_unlock(&logbuf_lock);
@@ -2618,10 +2618,10 @@ bool kmsg_dump_get_line_nolock(struct kmsg_dumper *dumper, bool syslog,
 	if (dumper->cur_seq >= printk_log_next_seq)
 		goto out;
 
-	msg = log_from_idx(dumper->cur_idx);
+	msg = printk_log_from_idx(dumper->cur_idx);
 	l = msg_print_text(msg, 0, syslog, line, size);
 
-	dumper->cur_idx = log_next(dumper->cur_idx);
+	dumper->cur_idx = printk_log_next(dumper->cur_idx);
 	dumper->cur_seq++;
 	ret = true;
 out:
@@ -2713,10 +2713,10 @@ bool kmsg_dump_get_buffer(struct kmsg_dumper *dumper, bool syslog,
 	idx = dumper->cur_idx;
 	prev = 0;
 	while (seq < dumper->next_seq) {
-		struct printk_log *msg = log_from_idx(idx);
+		struct printk_log *msg = printk_log_from_idx(idx);
 
 		l += msg_print_text(msg, prev, true, NULL, 0);
-		idx = log_next(idx);
+		idx = printk_log_next(idx);
 		seq++;
 		prev = msg->flags;
 	}
@@ -2726,10 +2726,10 @@ bool kmsg_dump_get_buffer(struct kmsg_dumper *dumper, bool syslog,
 	idx = dumper->cur_idx;
 	prev = 0;
 	while (l > size && seq < dumper->next_seq) {
-		struct printk_log *msg = log_from_idx(idx);
+		struct printk_log *msg = printk_log_from_idx(idx);
 
 		l -= msg_print_text(msg, prev, true, NULL, 0);
-		idx = log_next(idx);
+		idx = printk_log_next(idx);
 		seq++;
 		prev = msg->flags;
 	}
@@ -2741,10 +2741,10 @@ bool kmsg_dump_get_buffer(struct kmsg_dumper *dumper, bool syslog,
 	l = 0;
 	prev = 0;
 	while (seq < dumper->next_seq) {
-		struct printk_log *msg = log_from_idx(idx);
+		struct printk_log *msg = printk_log_from_idx(idx);
 
 		l += msg_print_text(msg, prev, syslog, buf + l, size - l);
-		idx = log_next(idx);
+		idx = printk_log_next(idx);
 		seq++;
 		prev = msg->flags;
 	}
-- 
1.7.8.112.g3fd21

[PATCH V2 09/23] printk: Rename enum log_flags to printk_log_flags

[Joe Perches]

Make this generic enum more specific to the printk subsystem.

Signed-off-by: Joe Perches <joe@perches.com>
---
 kernel/printk/printk.c |   32 +++++++++++++++++---------------
 1 files changed, 17 insertions(+), 15 deletions(-)

diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 992c064..341f2d9 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -187,7 +187,7 @@ static int console_may_schedule;
  * separated by ',', and find the message after the ';' character.
  */
 
-enum log_flags {
+enum printk_log_flags {
 	LOG_NOCONS	= 1,	/* already flushed, do not print to console */
 	LOG_NEWLINE	= 2,	/* text ended with a newline */
 	LOG_PREFIX	= 4,	/* text started with a prefix */
@@ -214,7 +214,7 @@ static DEFINE_RAW_SPINLOCK(logbuf_lock);
 /* the next printk record to read by syslog(READ) or /proc/kmsg */
 static u64 syslog_seq;
 static u32 syslog_idx;
-static enum log_flags syslog_prev;
+static enum printk_log_flags syslog_prev;
 static size_t syslog_partial;
 
 /* index and sequence number of the first record stored in the buffer */
@@ -228,7 +228,7 @@ static u32 printk_log_next_idx;
 /* the next printk record to write to the console */
 static u64 console_seq;
 static u32 console_idx;
-static enum log_flags console_prev;
+static enum printk_log_flags console_prev;
 
 /* the next printk record to read after the last 'clear' command */
 static u64 clear_seq;
@@ -297,7 +297,7 @@ static u32 printk_log_next(u32 idx)
 
 /* insert record into the buffer, discard old ones, update heads */
 static void printk_log_store(int facility, int level,
-			     enum log_flags flags, u64 ts_nsec,
+			     enum printk_log_flags flags, u64 ts_nsec,
 			     const char *dict, u16 dict_len,
 			     const char *text, u16 text_len)
 {
@@ -360,7 +360,7 @@ static void printk_log_store(int facility, int level,
 struct devkmsg_user {
 	u64 seq;
 	u32 idx;
-	enum log_flags prev;
+	enum printk_log_flags prev;
 	struct mutex lock;
 	char buf[8192];
 };
@@ -872,7 +872,8 @@ static size_t print_prefix(const struct printk_log *msg, bool syslog, char *buf)
 	return len;
 }
 
-static size_t msg_print_text(const struct printk_log *msg, enum log_flags prev,
+static size_t msg_print_text(const struct printk_log *msg,
+			     enum printk_log_flags prev,
 			     bool syslog, char *buf, size_t size)
 {
 	const char *text = printk_log_text(msg);
@@ -1009,7 +1010,7 @@ static int syslog_print_all(char __user *buf, int size, bool clear)
 		u64 next_seq;
 		u64 seq;
 		u32 idx;
-		enum log_flags prev;
+		enum printk_log_flags prev;
 
 		if (clear_seq < printk_log_first_seq) {
 			/* messages are gone, move to first available one */
@@ -1194,7 +1195,7 @@ int do_syslog(int type, char __user *buf, int len, bool from_file)
 		} else {
 			u64 seq = syslog_seq;
 			u32 idx = syslog_idx;
-			enum log_flags prev = syslog_prev;
+			enum printk_log_flags prev = syslog_prev;
 
 			error = 0;
 			while (seq < printk_log_next_seq) {
@@ -1383,11 +1384,11 @@ static struct cont {
 	u64 ts_nsec;			/* time of first print */
 	u8 level;			/* log level of first message */
 	u8 facility;			/* log level of first message */
-	enum log_flags flags;		/* prefix, newline flags */
+	enum printk_log_flags flags;	/* prefix, newline flags */
 	bool flushed:1;			/* buffer sealed and committed */
 } cont;
 
-static void cont_flush(enum log_flags flags)
+static void cont_flush(enum printk_log_flags flags)
 {
 	if (cont.flushed)
 		return;
@@ -1481,7 +1482,7 @@ asmlinkage int vprintk_emit(int facility, int level,
 	static char textbuf[LOG_LINE_MAX];
 	char *text = textbuf;
 	size_t text_len;
-	enum log_flags lflags = 0;
+	enum printk_log_flags lflags = 0;
 	unsigned long flags;
 	int this_cpu;
 	int printed_len = 0;
@@ -1688,11 +1689,11 @@ static u64 syslog_seq;
 static u32 syslog_idx;
 static u64 console_seq;
 static u32 console_idx;
-static enum log_flags syslog_prev;
+static enum printk_log_flags syslog_prev;
 static u64 printk_log_first_seq;
 static u32 printk_log_first_idx;
 static u64 printk_log_next_seq;
-static enum log_flags console_prev;
+static enum printk_log_flags console_prev;
 static struct cont {
 	size_t len;
 	size_t cons;
@@ -1702,7 +1703,8 @@ static struct cont {
 static struct printk_log *printk_log_from_idx(u32 idx) { return NULL; }
 static u32 printk_log_next(u32 idx) { return 0; }
 static void call_console_drivers(int level, const char *text, size_t len) {}
-static size_t msg_print_text(const struct printk_log *msg, enum log_flags prev,
+static size_t msg_print_text(const struct printk_log *msg,
+			     enum printk_log_flags prev,
 			     bool syslog, char *buf, size_t size) { return 0; }
 static size_t cont_print_text(char *text, size_t size) { return 0; }
 
@@ -2688,7 +2690,7 @@ bool kmsg_dump_get_buffer(struct kmsg_dumper *dumper, bool syslog,
 	u32 idx;
 	u64 next_seq;
 	u32 next_idx;
-	enum log_flags prev;
+	enum printk_log_flags prev;
 	size_t l = 0;
 	bool ret = false;
 
-- 
1.7.8.112.g3fd21

[PATCH V2 10/23] printk: Rename log_wait to printk_log_wait

[Joe Perches]

Make this generic variable more specific to the printk
subsystem to allow this variable to be used without
a specific extern.

Also update fs/proc/kmsg.c as it uses log_wait.

Signed-off-by: Joe Perches <joe@perches.com>
---
 fs/proc/kmsg.c         |    4 ++--
 kernel/printk/printk.c |   12 ++++++------
 2 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/fs/proc/kmsg.c b/fs/proc/kmsg.c
index bd4b5a7..16f2c85 100644
--- a/fs/proc/kmsg.c
+++ b/fs/proc/kmsg.c
@@ -17,7 +17,7 @@
 #include <asm/uaccess.h>
 #include <asm/io.h>
 
-extern wait_queue_head_t log_wait;
+extern wait_queue_head_t printk_log_wait;
 
 static int kmsg_open(struct inode * inode, struct file * file)
 {
@@ -41,7 +41,7 @@ static ssize_t kmsg_read(struct file *file, char __user *buf,
 
 static unsigned int kmsg_poll(struct file *file, poll_table *wait)
 {
-	poll_wait(file, &log_wait, wait);
+	poll_wait(file, &printk_log_wait, wait);
 	if (do_syslog(SYSLOG_ACTION_SIZE_UNREAD, NULL, 0, SYSLOG_FROM_FILE))
 		return POLLIN | POLLRDNORM;
 	return 0;
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 341f2d9..c87472b 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -63,7 +63,7 @@ void asmlinkage __attribute__((weak)) early_printk(const char *fmt, ...)
 #define MINIMUM_CONSOLE_LOGLEVEL 1 /* Minimum loglevel we let people use */
 #define DEFAULT_CONSOLE_LOGLEVEL 7 /* anything MORE serious than KERN_DEBUG */
 
-DECLARE_WAIT_QUEUE_HEAD(log_wait);
+DECLARE_WAIT_QUEUE_HEAD(printk_log_wait);
 
 int console_printk[4] = {
 	DEFAULT_CONSOLE_LOGLEVEL,	/* console_loglevel */
@@ -447,7 +447,7 @@ static ssize_t devkmsg_read(struct file *file, char __user *buf,
 		}
 
 		raw_spin_unlock_irq(&logbuf_lock);
-		ret = wait_event_interruptible(log_wait,
+		ret = wait_event_interruptible(printk_log_wait,
 					       user->seq != printk_log_next_seq);
 		if (ret)
 			goto out;
@@ -589,7 +589,7 @@ static unsigned int devkmsg_poll(struct file *file, poll_table *wait)
 	if (!user)
 		return POLLERR|POLLNVAL;
 
-	poll_wait(file, &log_wait, wait);
+	poll_wait(file, &printk_log_wait, wait);
 
 	raw_spin_lock_irq(&logbuf_lock);
 	if (user->seq < printk_log_next_seq) {
@@ -1122,7 +1122,7 @@ int do_syslog(int type, char __user *buf, int len, bool from_file)
 			error = -EFAULT;
 			goto out;
 		}
-		error = wait_event_interruptible(log_wait,
+		error = wait_event_interruptible(printk_log_wait,
 						 syslog_seq != printk_log_next_seq);
 		if (error)
 			goto out;
@@ -1948,7 +1948,7 @@ void printk_tick(void)
 			printk(KERN_WARNING "[sched_delayed] %s", buf);
 		}
 		if (pending & PRINTK_PENDING_WAKEUP)
-			wake_up_interruptible(&log_wait);
+			wake_up_interruptible(&printk_log_wait);
 	}
 }
 
@@ -1961,7 +1961,7 @@ int printk_needs_cpu(int cpu)
 
 void wake_up_klogd(void)
 {
-	if (waitqueue_active(&log_wait))
+	if (waitqueue_active(&printk_log_wait))
 		this_cpu_or(printk_pending, PRINTK_PENDING_WAKEUP);
 }
 
-- 
1.7.8.112.g3fd21

[PATCH V2 11/23] printk: Rename logbuf_lock to printk_logbuf_lock

[Joe Perches]

Make this generic name more specific to the printk
subsystem and allow it to become non-static.

Signed-off-by: Joe Perches <joe@perches.com>
---
 kernel/printk/printk.c |  102 ++++++++++++++++++++++++------------------------
 1 files changed, 51 insertions(+), 51 deletions(-)

diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index c87472b..709472f 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -205,10 +205,10 @@ struct printk_log {
 };
 
 /*
- * The logbuf_lock protects kmsg buffer, indices, counters. It is also
+ * The printk_logbuf_lock protects kmsg buffer, indices, counters. It is also
  * used in interesting ways to provide interlocking in console_unlock();
  */
-static DEFINE_RAW_SPINLOCK(logbuf_lock);
+static DEFINE_RAW_SPINLOCK(printk_logbuf_lock);
 
 #ifdef CONFIG_PRINTK
 /* the next printk record to read by syslog(READ) or /proc/kmsg */
@@ -248,7 +248,7 @@ static char __printk_log_buf[__PRINTK_LOG_BUF_LEN] __aligned(LOG_ALIGN);
 static char *printk_log_buf = __printk_log_buf;
 static u32 printk_log_buf_len = __PRINTK_LOG_BUF_LEN;
 
-/* cpu currently holding logbuf_lock */
+/* cpu currently holding printk_logbuf_lock */
 static volatile unsigned int logbuf_cpu = UINT_MAX;
 
 /* human readable text of the record */
@@ -438,20 +438,20 @@ static ssize_t devkmsg_read(struct file *file, char __user *buf,
 	ret = mutex_lock_interruptible(&user->lock);
 	if (ret)
 		return ret;
-	raw_spin_lock_irq(&logbuf_lock);
+	raw_spin_lock_irq(&printk_logbuf_lock);
 	while (user->seq == printk_log_next_seq) {
 		if (file->f_flags & O_NONBLOCK) {
 			ret = -EAGAIN;
-			raw_spin_unlock_irq(&logbuf_lock);
+			raw_spin_unlock_irq(&printk_logbuf_lock);
 			goto out;
 		}
 
-		raw_spin_unlock_irq(&logbuf_lock);
+		raw_spin_unlock_irq(&printk_logbuf_lock);
 		ret = wait_event_interruptible(printk_log_wait,
 					       user->seq != printk_log_next_seq);
 		if (ret)
 			goto out;
-		raw_spin_lock_irq(&logbuf_lock);
+		raw_spin_lock_irq(&printk_logbuf_lock);
 	}
 
 	if (user->seq < printk_log_first_seq) {
@@ -459,7 +459,7 @@ static ssize_t devkmsg_read(struct file *file, char __user *buf,
 		user->idx = printk_log_first_idx;
 		user->seq = printk_log_first_seq;
 		ret = -EPIPE;
-		raw_spin_unlock_irq(&logbuf_lock);
+		raw_spin_unlock_irq(&printk_logbuf_lock);
 		goto out;
 	}
 
@@ -526,7 +526,7 @@ static ssize_t devkmsg_read(struct file *file, char __user *buf,
 
 	user->idx = printk_log_next(user->idx);
 	user->seq++;
-	raw_spin_unlock_irq(&logbuf_lock);
+	raw_spin_unlock_irq(&printk_logbuf_lock);
 
 	if (len > count) {
 		ret = -EINVAL;
@@ -553,7 +553,7 @@ static loff_t devkmsg_llseek(struct file *file, loff_t offset, int whence)
 	if (offset)
 		return -ESPIPE;
 
-	raw_spin_lock_irq(&logbuf_lock);
+	raw_spin_lock_irq(&printk_logbuf_lock);
 	switch (whence) {
 	case SEEK_SET:
 		/* the first record */
@@ -577,7 +577,7 @@ static loff_t devkmsg_llseek(struct file *file, loff_t offset, int whence)
 	default:
 		ret = -EINVAL;
 	}
-	raw_spin_unlock_irq(&logbuf_lock);
+	raw_spin_unlock_irq(&printk_logbuf_lock);
 	return ret;
 }
 
@@ -591,14 +591,14 @@ static unsigned int devkmsg_poll(struct file *file, poll_table *wait)
 
 	poll_wait(file, &printk_log_wait, wait);
 
-	raw_spin_lock_irq(&logbuf_lock);
+	raw_spin_lock_irq(&printk_logbuf_lock);
 	if (user->seq < printk_log_next_seq) {
 		/* return error when data has vanished underneath us */
 		if (user->seq < printk_log_first_seq)
 			ret = POLLIN|POLLRDNORM|POLLERR|POLLPRI;
 		ret = POLLIN|POLLRDNORM;
 	}
-	raw_spin_unlock_irq(&logbuf_lock);
+	raw_spin_unlock_irq(&printk_logbuf_lock);
 
 	return ret;
 }
@@ -622,10 +622,10 @@ static int devkmsg_open(struct inode *inode, struct file *file)
 
 	mutex_init(&user->lock);
 
-	raw_spin_lock_irq(&logbuf_lock);
+	raw_spin_lock_irq(&printk_logbuf_lock);
 	user->idx = printk_log_first_idx;
 	user->seq = printk_log_first_seq;
-	raw_spin_unlock_irq(&logbuf_lock);
+	raw_spin_unlock_irq(&printk_logbuf_lock);
 
 	file->private_data = user;
 	return 0;
@@ -722,13 +722,13 @@ void __init setup_log_buf(int early)
 		return;
 	}
 
-	raw_spin_lock_irqsave(&logbuf_lock, flags);
+	raw_spin_lock_irqsave(&printk_logbuf_lock, flags);
 	printk_log_buf_len = new_printk_log_buf_len;
 	printk_log_buf = new_printk_log_buf;
 	new_printk_log_buf_len = 0;
 	free = __PRINTK_LOG_BUF_LEN - printk_log_next_idx;
 	memcpy(printk_log_buf, __printk_log_buf, __PRINTK_LOG_BUF_LEN);
-	raw_spin_unlock_irqrestore(&logbuf_lock, flags);
+	raw_spin_unlock_irqrestore(&printk_logbuf_lock, flags);
 
 	pr_info("printk_log_buf_len: %d\n", printk_log_buf_len);
 	pr_info("early log buf free: %d(%d%%)\n",
@@ -946,7 +946,7 @@ static int syslog_print(char __user *buf, int size)
 		size_t n;
 		size_t skip;
 
-		raw_spin_lock_irq(&logbuf_lock);
+		raw_spin_lock_irq(&printk_logbuf_lock);
 		if (syslog_seq < printk_log_first_seq) {
 			/* messages are gone, move to first one */
 			syslog_seq = printk_log_first_seq;
@@ -955,7 +955,7 @@ static int syslog_print(char __user *buf, int size)
 			syslog_partial = 0;
 		}
 		if (syslog_seq == printk_log_next_seq) {
-			raw_spin_unlock_irq(&logbuf_lock);
+			raw_spin_unlock_irq(&printk_logbuf_lock);
 			break;
 		}
 
@@ -976,7 +976,7 @@ static int syslog_print(char __user *buf, int size)
 			syslog_partial += n;
 		} else
 			n = 0;
-		raw_spin_unlock_irq(&logbuf_lock);
+		raw_spin_unlock_irq(&printk_logbuf_lock);
 
 		if (!n)
 			break;
@@ -1005,7 +1005,7 @@ static int syslog_print_all(char __user *buf, int size, bool clear)
 	if (!text)
 		return -ENOMEM;
 
-	raw_spin_lock_irq(&logbuf_lock);
+	raw_spin_lock_irq(&printk_logbuf_lock);
 	if (buf) {
 		u64 next_seq;
 		u64 seq;
@@ -1066,12 +1066,12 @@ static int syslog_print_all(char __user *buf, int size, bool clear)
 			seq++;
 			prev = msg->flags;
 
-			raw_spin_unlock_irq(&logbuf_lock);
+			raw_spin_unlock_irq(&printk_logbuf_lock);
 			if (copy_to_user(buf + len, text, textlen))
 				len = -EFAULT;
 			else
 				len += textlen;
-			raw_spin_lock_irq(&logbuf_lock);
+			raw_spin_lock_irq(&printk_logbuf_lock);
 
 			if (seq < printk_log_first_seq) {
 				/* messages are gone, move to next one */
@@ -1086,7 +1086,7 @@ static int syslog_print_all(char __user *buf, int size, bool clear)
 		clear_seq = printk_log_next_seq;
 		clear_idx = printk_log_next_idx;
 	}
-	raw_spin_unlock_irq(&logbuf_lock);
+	raw_spin_unlock_irq(&printk_logbuf_lock);
 
 	kfree(text);
 	return len;
@@ -1177,7 +1177,7 @@ int do_syslog(int type, char __user *buf, int len, bool from_file)
 		break;
 	/* Number of chars in the log buffer */
 	case SYSLOG_ACTION_SIZE_UNREAD:
-		raw_spin_lock_irq(&logbuf_lock);
+		raw_spin_lock_irq(&printk_logbuf_lock);
 		if (syslog_seq < printk_log_first_seq) {
 			/* messages are gone, move to first one */
 			syslog_seq = printk_log_first_seq;
@@ -1208,7 +1208,7 @@ int do_syslog(int type, char __user *buf, int len, bool from_file)
 			}
 			error -= syslog_partial;
 		}
-		raw_spin_unlock_irq(&logbuf_lock);
+		raw_spin_unlock_irq(&printk_logbuf_lock);
 		break;
 	/* Size of the log buffer */
 	case SYSLOG_ACTION_SIZE_BUFFER:
@@ -1289,7 +1289,7 @@ static void zap_locks(void)
 
 	debug_locks_off();
 	/* If a crash is occurring, make sure we can't deadlock */
-	raw_spin_lock_init(&logbuf_lock);
+	raw_spin_lock_init(&printk_logbuf_lock);
 	/* And make sure that we print immediately */
 	sema_init(&console_sem, 1);
 }
@@ -1325,12 +1325,12 @@ static inline int can_use_console(unsigned int cpu)
  * console_lock held, and 'console_locked' set) if it
  * is successful, false otherwise.
  *
- * This gets called with the 'logbuf_lock' spinlock held and
+ * This gets called with the 'printk_logbuf_lock' spinlock held and
  * interrupts disabled. It should return with 'lockbuf_lock'
  * released but interrupts still disabled.
  */
 static int console_trylock_for_printk(unsigned int cpu)
-	__releases(&logbuf_lock)
+	__releases(&printk_logbuf_lock)
 {
 	int retval = 0, wake = 0;
 
@@ -1352,7 +1352,7 @@ static int console_trylock_for_printk(unsigned int cpu)
 	logbuf_cpu = UINT_MAX;
 	if (wake)
 		up(&console_sem);
-	raw_spin_unlock(&logbuf_lock);
+	raw_spin_unlock(&printk_logbuf_lock);
 	return retval;
 }
 
@@ -1513,7 +1513,7 @@ asmlinkage int vprintk_emit(int facility, int level,
 	}
 
 	lockdep_off();
-	raw_spin_lock(&logbuf_lock);
+	raw_spin_lock(&printk_logbuf_lock);
 	logbuf_cpu = this_cpu;
 
 	if (recursion_bug) {
@@ -1603,7 +1603,7 @@ asmlinkage int vprintk_emit(int facility, int level,
 	 * The release will print out buffers and wake up /dev/kmsg and syslog()
 	 * users.
 	 *
-	 * The console_trylock_for_printk() function will release 'logbuf_lock'
+	 * The console_trylock_for_printk() function will release 'printk_logbuf_lock'
 	 * regardless of whether it actually gets the console semaphore or not.
 	 */
 	if (console_trylock_for_printk(this_cpu))
@@ -1970,7 +1970,7 @@ static void console_cont_flush(char *text, size_t size)
 	unsigned long flags;
 	size_t len;
 
-	raw_spin_lock_irqsave(&logbuf_lock, flags);
+	raw_spin_lock_irqsave(&printk_logbuf_lock, flags);
 
 	if (!cont.len)
 		goto out;
@@ -1984,14 +1984,14 @@ static void console_cont_flush(char *text, size_t size)
 		goto out;
 
 	len = cont_print_text(text, size);
-	raw_spin_unlock(&logbuf_lock);
+	raw_spin_unlock(&printk_logbuf_lock);
 	stop_critical_timings();
 	call_console_drivers(cont.level, text, len);
 	start_critical_timings();
 	local_irq_restore(flags);
 	return;
 out:
-	raw_spin_unlock_irqrestore(&logbuf_lock, flags);
+	raw_spin_unlock_irqrestore(&printk_logbuf_lock, flags);
 }
 
 /**
@@ -2031,7 +2031,7 @@ again:
 		size_t len;
 		int level;
 
-		raw_spin_lock_irqsave(&logbuf_lock, flags);
+		raw_spin_lock_irqsave(&printk_logbuf_lock, flags);
 		if (seen_seq != printk_log_next_seq) {
 			wake_klogd = true;
 			seen_seq = printk_log_next_seq;
@@ -2071,7 +2071,7 @@ skip:
 		console_idx = printk_log_next(console_idx);
 		console_seq++;
 		console_prev = msg->flags;
-		raw_spin_unlock(&logbuf_lock);
+		raw_spin_unlock(&printk_logbuf_lock);
 
 		stop_critical_timings();	/* don't trace print latency */
 		call_console_drivers(level, text, len);
@@ -2084,7 +2084,7 @@ skip:
 	if (unlikely(exclusive_console))
 		exclusive_console = NULL;
 
-	raw_spin_unlock(&logbuf_lock);
+	raw_spin_unlock(&printk_logbuf_lock);
 
 	up(&console_sem);
 
@@ -2094,9 +2094,9 @@ skip:
 	 * there's a new owner and the console_unlock() from them will do the
 	 * flush, no worries.
 	 */
-	raw_spin_lock(&logbuf_lock);
+	raw_spin_lock(&printk_logbuf_lock);
 	retry = console_seq != printk_log_next_seq;
-	raw_spin_unlock_irqrestore(&logbuf_lock, flags);
+	raw_spin_unlock_irqrestore(&printk_logbuf_lock, flags);
 
 	if (retry && console_trylock())
 		goto again;
@@ -2326,11 +2326,11 @@ void register_console(struct console *newcon)
 		 * console_unlock(); will print out the buffered messages
 		 * for us.
 		 */
-		raw_spin_lock_irqsave(&logbuf_lock, flags);
+		raw_spin_lock_irqsave(&printk_logbuf_lock, flags);
 		console_seq = syslog_seq;
 		console_idx = syslog_idx;
 		console_prev = syslog_prev;
-		raw_spin_unlock_irqrestore(&logbuf_lock, flags);
+		raw_spin_unlock_irqrestore(&printk_logbuf_lock, flags);
 		/*
 		 * We're about to replay the log buffer.  Only do this to the
 		 * just-registered console to avoid excessive message spam to
@@ -2565,12 +2565,12 @@ void kmsg_dump(enum kmsg_dump_reason reason)
 		/* initialize iterator with data about the stored records */
 		dumper->active = true;
 
-		raw_spin_lock_irqsave(&logbuf_lock, flags);
+		raw_spin_lock_irqsave(&printk_logbuf_lock, flags);
 		dumper->cur_seq = clear_seq;
 		dumper->cur_idx = clear_idx;
 		dumper->next_seq = printk_log_next_seq;
 		dumper->next_idx = printk_log_next_idx;
-		raw_spin_unlock_irqrestore(&logbuf_lock, flags);
+		raw_spin_unlock_irqrestore(&printk_logbuf_lock, flags);
 
 		/* invoke dumper which will iterate over records */
 		dumper->dump(dumper, reason);
@@ -2655,9 +2655,9 @@ bool kmsg_dump_get_line(struct kmsg_dumper *dumper, bool syslog,
 	unsigned long flags;
 	bool ret;
 
-	raw_spin_lock_irqsave(&logbuf_lock, flags);
+	raw_spin_lock_irqsave(&printk_logbuf_lock, flags);
 	ret = kmsg_dump_get_line_nolock(dumper, syslog, line, size, len);
-	raw_spin_unlock_irqrestore(&logbuf_lock, flags);
+	raw_spin_unlock_irqrestore(&printk_logbuf_lock, flags);
 
 	return ret;
 }
@@ -2697,7 +2697,7 @@ bool kmsg_dump_get_buffer(struct kmsg_dumper *dumper, bool syslog,
 	if (!dumper->active)
 		goto out;
 
-	raw_spin_lock_irqsave(&logbuf_lock, flags);
+	raw_spin_lock_irqsave(&printk_logbuf_lock, flags);
 	if (dumper->cur_seq < printk_log_first_seq) {
 		/* messages are gone, move to first available one */
 		dumper->cur_seq = printk_log_first_seq;
@@ -2706,7 +2706,7 @@ bool kmsg_dump_get_buffer(struct kmsg_dumper *dumper, bool syslog,
 
 	/* last entry */
 	if (dumper->cur_seq >= dumper->next_seq) {
-		raw_spin_unlock_irqrestore(&logbuf_lock, flags);
+		raw_spin_unlock_irqrestore(&printk_logbuf_lock, flags);
 		goto out;
 	}
 
@@ -2754,7 +2754,7 @@ bool kmsg_dump_get_buffer(struct kmsg_dumper *dumper, bool syslog,
 	dumper->next_seq = next_seq;
 	dumper->next_idx = next_idx;
 	ret = true;
-	raw_spin_unlock_irqrestore(&logbuf_lock, flags);
+	raw_spin_unlock_irqrestore(&printk_logbuf_lock, flags);
 out:
 	if (len)
 		*len = l;
@@ -2792,9 +2792,9 @@ void kmsg_dump_rewind(struct kmsg_dumper *dumper)
 {
 	unsigned long flags;
 
-	raw_spin_lock_irqsave(&logbuf_lock, flags);
+	raw_spin_lock_irqsave(&printk_logbuf_lock, flags);
 	kmsg_dump_rewind_nolock(dumper);
-	raw_spin_unlock_irqrestore(&logbuf_lock, flags);
+	raw_spin_unlock_irqrestore(&printk_logbuf_lock, flags);
 }
 EXPORT_SYMBOL_GPL(kmsg_dump_rewind);
 #endif
-- 
1.7.8.112.g3fd21

[PATCH V2 12/23] printk: Rename clear_seq and clear_idx variables

[Joe Perches]

Make these variables more specific to the printk log subsystem
adding prefix printk_log_.  This allows them to become non-static.

Signed-off-by: Joe Perches <joe@perches.com>
---
 kernel/printk/printk.c |   34 +++++++++++++++++-----------------
 1 files changed, 17 insertions(+), 17 deletions(-)

diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 709472f..3785ac4 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -231,8 +231,8 @@ static u32 console_idx;
 static enum printk_log_flags console_prev;
 
 /* the next printk record to read after the last 'clear' command */
-static u64 clear_seq;
-static u32 clear_idx;
+static u64 printk_log_clear_seq;
+static u32 printk_log_clear_idx;
 
 #define PREFIX_MAX		32
 #define LOG_LINE_MAX		1024 - PREFIX_MAX
@@ -566,8 +566,8 @@ static loff_t devkmsg_llseek(struct file *file, loff_t offset, int whence)
 		 * like issued by 'dmesg -c'. Reading /dev/kmsg itself
 		 * changes no global state, and does not clear anything.
 		 */
-		user->idx = clear_idx;
-		user->seq = clear_seq;
+		user->idx = printk_log_clear_idx;
+		user->seq = printk_log_clear_seq;
 		break;
 	case SEEK_END:
 		/* after the last record */
@@ -1012,18 +1012,18 @@ static int syslog_print_all(char __user *buf, int size, bool clear)
 		u32 idx;
 		enum printk_log_flags prev;
 
-		if (clear_seq < printk_log_first_seq) {
+		if (printk_log_clear_seq < printk_log_first_seq) {
 			/* messages are gone, move to first available one */
-			clear_seq = printk_log_first_seq;
-			clear_idx = printk_log_first_idx;
+			printk_log_clear_seq = printk_log_first_seq;
+			printk_log_clear_idx = printk_log_first_idx;
 		}
 
 		/*
 		 * Find first record that fits, including all following records,
 		 * into the user-provided buffer for this dump.
 		 */
-		seq = clear_seq;
-		idx = clear_idx;
+		seq = printk_log_clear_seq;
+		idx = printk_log_clear_idx;
 		prev = 0;
 		while (seq < printk_log_next_seq) {
 			struct printk_log *msg = printk_log_from_idx(idx);
@@ -1035,8 +1035,8 @@ static int syslog_print_all(char __user *buf, int size, bool clear)
 		}
 
 		/* move first record forward until length fits into the buffer */
-		seq = clear_seq;
-		idx = clear_idx;
+		seq = printk_log_clear_seq;
+		idx = printk_log_clear_idx;
 		prev = 0;
 		while (len > size && seq < printk_log_next_seq) {
 			struct printk_log *msg = printk_log_from_idx(idx);
@@ -1083,8 +1083,8 @@ static int syslog_print_all(char __user *buf, int size, bool clear)
 	}
 
 	if (clear) {
-		clear_seq = printk_log_next_seq;
-		clear_idx = printk_log_next_idx;
+		printk_log_clear_seq = printk_log_next_seq;
+		printk_log_clear_idx = printk_log_next_idx;
 	}
 	raw_spin_unlock_irq(&printk_logbuf_lock);
 
@@ -2566,8 +2566,8 @@ void kmsg_dump(enum kmsg_dump_reason reason)
 		dumper->active = true;
 
 		raw_spin_lock_irqsave(&printk_logbuf_lock, flags);
-		dumper->cur_seq = clear_seq;
-		dumper->cur_idx = clear_idx;
+		dumper->cur_seq = printk_log_clear_seq;
+		dumper->cur_idx = printk_log_clear_idx;
 		dumper->next_seq = printk_log_next_seq;
 		dumper->next_idx = printk_log_next_idx;
 		raw_spin_unlock_irqrestore(&printk_logbuf_lock, flags);
@@ -2774,8 +2774,8 @@ EXPORT_SYMBOL_GPL(kmsg_dump_get_buffer);
  */
 void kmsg_dump_rewind_nolock(struct kmsg_dumper *dumper)
 {
-	dumper->cur_seq = clear_seq;
-	dumper->cur_idx = clear_idx;
+	dumper->cur_seq = printk_log_clear_seq;
+	dumper->cur_idx = printk_log_clear_idx;
 	dumper->next_seq = printk_log_next_seq;
 	dumper->next_idx = printk_log_next_idx;
 }
-- 
1.7.8.112.g3fd21

[PATCH V2 13/23] printk: Remove static from printk_ variables

[Joe Perches]

Allow a separation of functions and variables into
multiple files.

Signed-off-by: Joe Perches <joe@perches.com>
---
 kernel/printk/printk.c |   46 +++++++++++++++++++++++-----------------------
 1 files changed, 23 insertions(+), 23 deletions(-)

diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 3785ac4..0134b2e 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -208,7 +208,7 @@ struct printk_log {
  * The printk_logbuf_lock protects kmsg buffer, indices, counters. It is also
  * used in interesting ways to provide interlocking in console_unlock();
  */
-static DEFINE_RAW_SPINLOCK(printk_logbuf_lock);
+DEFINE_RAW_SPINLOCK(printk_logbuf_lock);
 
 #ifdef CONFIG_PRINTK
 /* the next printk record to read by syslog(READ) or /proc/kmsg */
@@ -218,12 +218,12 @@ static enum printk_log_flags syslog_prev;
 static size_t syslog_partial;
 
 /* index and sequence number of the first record stored in the buffer */
-static u64 printk_log_first_seq;
-static u32 printk_log_first_idx;
+u64 printk_log_first_seq;
+u32 printk_log_first_idx;
 
 /* index and sequence number of the next record to store in the buffer */
-static u64 printk_log_next_seq;
-static u32 printk_log_next_idx;
+u64 printk_log_next_seq;
+u32 printk_log_next_idx;
 
 /* the next printk record to write to the console */
 static u64 console_seq;
@@ -231,8 +231,8 @@ static u32 console_idx;
 static enum printk_log_flags console_prev;
 
 /* the next printk record to read after the last 'clear' command */
-static u64 printk_log_clear_seq;
-static u32 printk_log_clear_idx;
+u64 printk_log_clear_seq;
+u32 printk_log_clear_idx;
 
 #define PREFIX_MAX		32
 #define LOG_LINE_MAX		1024 - PREFIX_MAX
@@ -244,27 +244,27 @@ static u32 printk_log_clear_idx;
 #define LOG_ALIGN __alignof__(struct printk_log)
 #endif
 #define __PRINTK_LOG_BUF_LEN (1 << CONFIG_LOG_BUF_SHIFT)
-static char __printk_log_buf[__PRINTK_LOG_BUF_LEN] __aligned(LOG_ALIGN);
-static char *printk_log_buf = __printk_log_buf;
-static u32 printk_log_buf_len = __PRINTK_LOG_BUF_LEN;
+char __printk_log_buf[__PRINTK_LOG_BUF_LEN] __aligned(LOG_ALIGN);
+char *printk_log_buf = __printk_log_buf;
+u32 printk_log_buf_len = __PRINTK_LOG_BUF_LEN;
 
 /* cpu currently holding printk_logbuf_lock */
 static volatile unsigned int logbuf_cpu = UINT_MAX;
 
 /* human readable text of the record */
-static char *printk_log_text(const struct printk_log *msg)
+char *printk_log_text(const struct printk_log *msg)
 {
 	return (char *)msg + sizeof(struct printk_log);
 }
 
 /* optional key/value pair dictionary attached to the record */
-static char *printk_log_dict(const struct printk_log *msg)
+char *printk_log_dict(const struct printk_log *msg)
 {
 	return (char *)msg + sizeof(struct printk_log) + msg->text_len;
 }
 
 /* get record by index; idx must point to valid msg */
-static struct printk_log *printk_log_from_idx(u32 idx)
+struct printk_log *printk_log_from_idx(u32 idx)
 {
 	struct printk_log *msg = (struct printk_log *)(printk_log_buf + idx);
 
@@ -278,7 +278,7 @@ static struct printk_log *printk_log_from_idx(u32 idx)
 }
 
 /* get next record; idx must point to valid msg */
-static u32 printk_log_next(u32 idx)
+u32 printk_log_next(u32 idx)
 {
 	struct printk_log *msg = (struct printk_log *)(printk_log_buf + idx);
 
@@ -296,10 +296,10 @@ static u32 printk_log_next(u32 idx)
 }
 
 /* insert record into the buffer, discard old ones, update heads */
-static void printk_log_store(int facility, int level,
-			     enum printk_log_flags flags, u64 ts_nsec,
-			     const char *dict, u16 dict_len,
-			     const char *text, u16 text_len)
+void printk_log_store(int facility, int level,
+		      enum printk_log_flags flags, u64 ts_nsec,
+		      const char *dict, u16 dict_len,
+		      const char *text, u16 text_len)
 {
 	struct printk_log *msg;
 	u32 size, pad_len;
@@ -1690,9 +1690,9 @@ static u32 syslog_idx;
 static u64 console_seq;
 static u32 console_idx;
 static enum printk_log_flags syslog_prev;
-static u64 printk_log_first_seq;
-static u32 printk_log_first_idx;
-static u64 printk_log_next_seq;
+u64 printk_log_first_seq;
+u32 printk_log_first_idx;
+u64 printk_log_next_seq;
 static enum printk_log_flags console_prev;
 static struct cont {
 	size_t len;
@@ -1700,8 +1700,8 @@ static struct cont {
 	u8 level;
 	bool flushed:1;
 } cont;
-static struct printk_log *printk_log_from_idx(u32 idx) { return NULL; }
-static u32 printk_log_next(u32 idx) { return 0; }
+struct printk_log *printk_log_from_idx(u32 idx) { return NULL; }
+u32 printk_log_next(u32 idx) { return 0; }
 static void call_console_drivers(int level, const char *text, size_t len) {}
 static size_t msg_print_text(const struct printk_log *msg,
 			     enum printk_log_flags prev,
-- 
1.7.8.112.g3fd21

[PATCH V2 14/23] printk: Rename LOG_ALIGN to PRINTK_LOG_ALIGN

[Joe Perches]

Make the #define more specific to the printk subsystem.

Signed-off-by: Joe Perches <joe@perches.com>
---
 kernel/printk/printk.c |    8 ++++----
 1 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 0134b2e..bc0b4ed 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -239,12 +239,12 @@ u32 printk_log_clear_idx;
 
 /* record buffer */
 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
-#define LOG_ALIGN 4
+#define PRINTK_LOG_ALIGN 4
 #else
-#define LOG_ALIGN __alignof__(struct printk_log)
+#define PRINTK_LOG_ALIGN __alignof__(struct printk_log)
 #endif
 #define __PRINTK_LOG_BUF_LEN (1 << CONFIG_LOG_BUF_SHIFT)
-char __printk_log_buf[__PRINTK_LOG_BUF_LEN] __aligned(LOG_ALIGN);
+char __printk_log_buf[__PRINTK_LOG_BUF_LEN] __aligned(PRINTK_LOG_ALIGN);
 char *printk_log_buf = __printk_log_buf;
 u32 printk_log_buf_len = __PRINTK_LOG_BUF_LEN;
 
@@ -306,7 +306,7 @@ void printk_log_store(int facility, int level,
 
 	/* number of '\0' padding bytes to next message */
 	size = sizeof(struct printk_log) + text_len + dict_len;
-	pad_len = (-size) & (LOG_ALIGN - 1);
+	pad_len = (-size) & (PRINTK_LOG_ALIGN - 1);
 	size += pad_len;
 
 	while (printk_log_first_seq < printk_log_next_seq) {
-- 
1.7.8.112.g3fd21

[PATCH V2 15/23] printk: Add and use printk_log.h

[Joe Perches]

Create a header file for printk_log functions and variables.

Signed-off-by: Joe Perches <joe@perches.com>
---
 kernel/printk/printk.c     |   91 +----------------------------------
 kernel/printk/printk_log.h |  115 ++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 116 insertions(+), 90 deletions(-)
 create mode 100644 kernel/printk/printk_log.h

diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index bc0b4ed..3b18ade 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -48,6 +48,7 @@
 
 #include "console_cmdline.h"
 #include "braille.h"
+#include "printk_log.h"
 
 /*
  * Architectures can override it:
@@ -121,90 +122,6 @@ EXPORT_SYMBOL(console_set_on_cmdline);
 static int console_may_schedule;
 
 /*
- * The printk log buffer consists of a chain of concatenated variable
- * length records. Every record starts with a record header, containing
- * the overall length of the record.
- *
- * The heads to the first and last entry in the buffer, as well as the
- * sequence numbers of these both entries are maintained when messages
- * are stored..
- *
- * If the heads indicate available messages, the length in the header
- * tells the start next message. A length == 0 for the next message
- * indicates a wrap-around to the beginning of the buffer.
- *
- * Every record carries the monotonic timestamp in microseconds, as well as
- * the standard userspace syslog level and syslog facility. The usual
- * kernel messages use LOG_KERN; userspace-injected messages always carry
- * a matching syslog facility, by default LOG_USER. The origin of every
- * message can be reliably determined that way.
- *
- * The human readable log message directly follows the message header. The
- * length of the message text is stored in the header, the stored message
- * is not terminated.
- *
- * Optionally, a message can carry a dictionary of properties (key/value pairs),
- * to provide userspace with a machine-readable message context.
- *
- * Examples for well-defined, commonly used property names are:
- *   DEVICE=b12:8               device identifier
- *                                b12:8         block dev_t
- *                                c127:3        char dev_t
- *                                n8            netdev ifindex
- *                                +sound:card0  subsystem:devname
- *   SUBSYSTEM=pci              driver-core subsystem name
- *
- * Valid characters in property names are [a-zA-Z0-9.-_]. The plain text value
- * follows directly after a '=' character. Every property is terminated by
- * a '\0' character. The last property is not terminated.
- *
- * Example of a message structure:
- *   0000  ff 8f 00 00 00 00 00 00      monotonic time in nsec
- *   0008  34 00                        record is 52 bytes long
- *   000a        0b 00                  text is 11 bytes long
- *   000c              1f 00            dictionary is 23 bytes long
- *   000e                    03 00      LOG_KERN (facility) LOG_ERR (level)
- *   0010  69 74 27 73 20 61 20 6c      "it's a l"
- *         69 6e 65                     "ine"
- *   001b           44 45 56 49 43      "DEVIC"
- *         45 3d 62 38 3a 32 00 44      "E=b8:2\0D"
- *         52 49 56 45 52 3d 62 75      "RIVER=bu"
- *         67                           "g"
- *   0032     00 00 00                  padding to next message header
- *
- * The 'struct printk_log' buffer header must never be directly exported to
- * userspace, it is a kernel-private implementation detail that might
- * need to be changed in the future, when the requirements change.
- *
- * /dev/kmsg exports the structured data in the following line format:
- *   "level,sequnum,timestamp;<message text>\n"
- *
- * The optional key/value pairs are attached as continuation lines starting
- * with a space character and terminated by a newline. All possible
- * non-prinatable characters are escaped in the "\xff" notation.
- *
- * Users of the export format should ignore possible additional values
- * separated by ',', and find the message after the ';' character.
- */
-
-enum printk_log_flags {
-	LOG_NOCONS	= 1,	/* already flushed, do not print to console */
-	LOG_NEWLINE	= 2,	/* text ended with a newline */
-	LOG_PREFIX	= 4,	/* text started with a prefix */
-	LOG_CONT	= 8,	/* text is a fragment of a continuation line */
-};
-
-struct printk_log {
-	u64 ts_nsec;		/* timestamp in nanoseconds */
-	u16 len;		/* length of entire record */
-	u16 text_len;		/* length of text buffer */
-	u16 dict_len;		/* length of dictionary buffer */
-	u8 facility;		/* syslog facility */
-	u8 flags:5;		/* internal record flags */
-	u8 level:3;		/* syslog level */
-};
-
-/*
  * The printk_logbuf_lock protects kmsg buffer, indices, counters. It is also
  * used in interesting ways to provide interlocking in console_unlock();
  */
@@ -238,12 +155,6 @@ u32 printk_log_clear_idx;
 #define LOG_LINE_MAX		1024 - PREFIX_MAX
 
 /* record buffer */
-#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
-#define PRINTK_LOG_ALIGN 4
-#else
-#define PRINTK_LOG_ALIGN __alignof__(struct printk_log)
-#endif
-#define __PRINTK_LOG_BUF_LEN (1 << CONFIG_LOG_BUF_SHIFT)
 char __printk_log_buf[__PRINTK_LOG_BUF_LEN] __aligned(PRINTK_LOG_ALIGN);
 char *printk_log_buf = __printk_log_buf;
 u32 printk_log_buf_len = __PRINTK_LOG_BUF_LEN;
diff --git a/kernel/printk/printk_log.h b/kernel/printk/printk_log.h
new file mode 100644
index 0000000..0327f8d
--- /dev/null
+++ b/kernel/printk/printk_log.h
@@ -0,0 +1,115 @@
+#ifndef _PRINTK_LOG_H
+#define _PRINTK_LOG_H
+
+/*
+ * The printk log buffer consists of a chain of concatenated variable
+ * length records. Every record starts with a record header, containing
+ * the overall length of the record.
+ *
+ * The heads to the first and last entry in the buffer, as well as the
+ * sequence numbers of these both entries are maintained when messages
+ * are stored..
+ *
+ * If the heads indicate available messages, the length in the header
+ * tells the start next message. A length == 0 for the next message
+ * indicates a wrap-around to the beginning of the buffer.
+ *
+ * Every record carries the monotonic timestamp in microseconds, as well as
+ * the standard userspace syslog level and syslog facility. The usual
+ * kernel messages use LOG_KERN; userspace-injected messages always carry
+ * a matching syslog facility, by default LOG_USER. The origin of every
+ * message can be reliably determined that way.
+ *
+ * The human readable log message directly follows the message header. The
+ * length of the message text is stored in the header, the stored message
+ * is not terminated.
+ *
+ * Optionally, a message can carry a dictionary of properties (key/value pairs),
+ * to provide userspace with a machine-readable message context.
+ *
+ * Examples for well-defined, commonly used property names are:
+ *   DEVICE=b12:8               device identifier
+ *                                b12:8         block dev_t
+ *                                c127:3        char dev_t
+ *                                n8            netdev ifindex
+ *                                +sound:card0  subsystem:devname
+ *   SUBSYSTEM=pci              driver-core subsystem name
+ *
+ * Valid characters in property names are [a-zA-Z0-9.-_]. The plain text value
+ * follows directly after a '=' character. Every property is terminated by
+ * a '\0' character. The last property is not terminated.
+ *
+ * Example of a message structure:
+ *   0000  ff 8f 00 00 00 00 00 00      monotonic time in nsec
+ *   0008  34 00                        record is 52 bytes long
+ *   000a        0b 00                  text is 11 bytes long
+ *   000c              1f 00            dictionary is 23 bytes long
+ *   000e                    03 00      LOG_KERN (facility) LOG_ERR (level)
+ *   0010  69 74 27 73 20 61 20 6c      "it's a l"
+ *         69 6e 65                     "ine"
+ *   001b           44 45 56 49 43      "DEVIC"
+ *         45 3d 62 38 3a 32 00 44      "E=b8:2\0D"
+ *         52 49 56 45 52 3d 62 75      "RIVER=bu"
+ *         67                           "g"
+ *   0032     00 00 00                  padding to next message header
+ *
+ * The 'struct printk_log' buffer header must never be directly exported to
+ * userspace, it is a kernel-private implementation detail that might
+ * need to be changed in the future, when the requirements change.
+ *
+ * /dev/kmsg exports the structured data in the following line format:
+ *   "level,sequnum,timestamp;<message text>\n"
+ *
+ * The optional key/value pairs are attached as continuation lines starting
+ * with a space character and terminated by a newline. All possible
+ * non-prinatable characters are escaped in the "\xff" notation.
+ *
+ * Users of the export format should ignore possible additional values
+ * separated by ',', and find the message after the ';' character.
+ */
+
+enum printk_log_flags {
+	LOG_NOCONS	= 1,	/* already flushed, do not print to console */
+	LOG_NEWLINE	= 2,	/* text ended with a newline */
+	LOG_PREFIX	= 4,	/* text started with a prefix */
+	LOG_CONT	= 8,	/* text is a fragment of a continuation line */
+};
+
+struct printk_log {
+	u64 ts_nsec;		/* timestamp in nanoseconds */
+	u16 len;		/* length of entire record */
+	u16 text_len;		/* length of text buffer */
+	u16 dict_len;		/* length of dictionary buffer */
+	u8 facility;		/* syslog facility */
+	u8 flags:5;		/* internal record flags */
+	u8 level:3;		/* syslog level */
+};
+
+#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
+#define PRINTK_LOG_ALIGN 4
+#else
+#define PRINTK_LOG_ALIGN __alignof__(struct printk_log)
+#endif
+#define __PRINTK_LOG_BUF_LEN (1 << CONFIG_LOG_BUF_SHIFT)
+
+extern raw_spinlock_t printk_logbuf_lock;
+extern u64 printk_log_first_seq;
+extern u32 printk_log_first_idx;
+extern u64 printk_log_next_seq;
+extern u32 printk_log_next_idx;
+extern u64 printk_log_clear_seq;
+extern u32 printk_log_clear_idx;
+extern char __printk_log_buf[__PRINTK_LOG_BUF_LEN] __aligned(PRINTK_LOG_ALIGN);
+extern char *printk_log_buf;
+extern u32 printk_log_buf_len;
+
+char *printk_log_text(const struct printk_log *msg);
+char *printk_log_dict(const struct printk_log *msg);
+struct printk_log *printk_log_from_idx(u32 idx);
+u32 printk_log_next(u32 idx);
+void printk_log_store(int facility, int level,
+		      enum printk_log_flags flags, u64 ts_nsec,
+		      const char *dict, u16 dict_len,
+		      const char *text, u16 text_len);
+
+#endif
-- 
1.7.8.112.g3fd21

[PATCH V2 16/23] printk: Add printk_log.c

[Joe Perches]

Move print_log variables and functions into a separate file.

Signed-off-by: Joe Perches <joe@perches.com>
---
 kernel/printk/Makefile     |    1 +
 kernel/printk/printk.c     |  128 -------------------------------------
 kernel/printk/printk_log.c |  149 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 150 insertions(+), 128 deletions(-)
 create mode 100644 kernel/printk/printk_log.c

diff --git a/kernel/printk/Makefile b/kernel/printk/Makefile
index 85405bd..a692b68 100644
--- a/kernel/printk/Makefile
+++ b/kernel/printk/Makefile
@@ -1,2 +1,3 @@
 obj-y	= printk.o
+obj-y	+= printk_log.o
 obj-$(CONFIG_A11Y_BRAILLE_CONSOLE)	+= braille.o
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 3b18ade..3b5c10e 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -121,12 +121,6 @@ EXPORT_SYMBOL(console_set_on_cmdline);
 /* Flag: console code may call schedule() */
 static int console_may_schedule;
 
-/*
- * The printk_logbuf_lock protects kmsg buffer, indices, counters. It is also
- * used in interesting ways to provide interlocking in console_unlock();
- */
-DEFINE_RAW_SPINLOCK(printk_logbuf_lock);
-
 #ifdef CONFIG_PRINTK
 /* the next printk record to read by syslog(READ) or /proc/kmsg */
 static u64 syslog_seq;
@@ -134,139 +128,17 @@ static u32 syslog_idx;
 static enum printk_log_flags syslog_prev;
 static size_t syslog_partial;
 
-/* index and sequence number of the first record stored in the buffer */
-u64 printk_log_first_seq;
-u32 printk_log_first_idx;
-
-/* index and sequence number of the next record to store in the buffer */
-u64 printk_log_next_seq;
-u32 printk_log_next_idx;
-
 /* the next printk record to write to the console */
 static u64 console_seq;
 static u32 console_idx;
 static enum printk_log_flags console_prev;
 
-/* the next printk record to read after the last 'clear' command */
-u64 printk_log_clear_seq;
-u32 printk_log_clear_idx;
-
 #define PREFIX_MAX		32
 #define LOG_LINE_MAX		1024 - PREFIX_MAX
 
-/* record buffer */
-char __printk_log_buf[__PRINTK_LOG_BUF_LEN] __aligned(PRINTK_LOG_ALIGN);
-char *printk_log_buf = __printk_log_buf;
-u32 printk_log_buf_len = __PRINTK_LOG_BUF_LEN;
-
 /* cpu currently holding printk_logbuf_lock */
 static volatile unsigned int logbuf_cpu = UINT_MAX;
 
-/* human readable text of the record */
-char *printk_log_text(const struct printk_log *msg)
-{
-	return (char *)msg + sizeof(struct printk_log);
-}
-
-/* optional key/value pair dictionary attached to the record */
-char *printk_log_dict(const struct printk_log *msg)
-{
-	return (char *)msg + sizeof(struct printk_log) + msg->text_len;
-}
-
-/* get record by index; idx must point to valid msg */
-struct printk_log *printk_log_from_idx(u32 idx)
-{
-	struct printk_log *msg = (struct printk_log *)(printk_log_buf + idx);
-
-	/*
-	 * A length == 0 record is the end of buffer marker. Wrap around and
-	 * read the message at the start of the buffer.
-	 */
-	if (!msg->len)
-		return (struct printk_log *)printk_log_buf;
-	return msg;
-}
-
-/* get next record; idx must point to valid msg */
-u32 printk_log_next(u32 idx)
-{
-	struct printk_log *msg = (struct printk_log *)(printk_log_buf + idx);
-
-	/* length == 0 indicates the end of the buffer; wrap */
-	/*
-	 * A length == 0 record is the end of buffer marker. Wrap around and
-	 * read the message at the start of the buffer as *this* one, and
-	 * return the one after that.
-	 */
-	if (!msg->len) {
-		msg = (struct printk_log *)printk_log_buf;
-		return msg->len;
-	}
-	return idx + msg->len;
-}
-
-/* insert record into the buffer, discard old ones, update heads */
-void printk_log_store(int facility, int level,
-		      enum printk_log_flags flags, u64 ts_nsec,
-		      const char *dict, u16 dict_len,
-		      const char *text, u16 text_len)
-{
-	struct printk_log *msg;
-	u32 size, pad_len;
-
-	/* number of '\0' padding bytes to next message */
-	size = sizeof(struct printk_log) + text_len + dict_len;
-	pad_len = (-size) & (PRINTK_LOG_ALIGN - 1);
-	size += pad_len;
-
-	while (printk_log_first_seq < printk_log_next_seq) {
-		u32 free;
-
-		if (printk_log_next_idx > printk_log_first_idx)
-			free = max(printk_log_buf_len - printk_log_next_idx, printk_log_first_idx);
-		else
-			free = printk_log_first_idx - printk_log_next_idx;
-
-		if (free > size + sizeof(struct printk_log))
-			break;
-
-		/* drop old messages until we have enough contiuous space */
-		printk_log_first_idx = printk_log_next(printk_log_first_idx);
-		printk_log_first_seq++;
-	}
-
-	if (printk_log_next_idx + size + sizeof(struct printk_log) >= printk_log_buf_len) {
-		/*
-		 * This message + an additional empty header does not fit
-		 * at the end of the buffer. Add an empty header with len == 0
-		 * to signify a wrap around.
-		 */
-		memset(printk_log_buf + printk_log_next_idx, 0, sizeof(struct printk_log));
-		printk_log_next_idx = 0;
-	}
-
-	/* fill message */
-	msg = (struct printk_log *)(printk_log_buf + printk_log_next_idx);
-	memcpy(printk_log_text(msg), text, text_len);
-	msg->text_len = text_len;
-	memcpy(printk_log_dict(msg), dict, dict_len);
-	msg->dict_len = dict_len;
-	msg->facility = facility;
-	msg->level = level & 7;
-	msg->flags = flags & 0x1f;
-	if (ts_nsec > 0)
-		msg->ts_nsec = ts_nsec;
-	else
-		msg->ts_nsec = local_clock();
-	memset(printk_log_dict(msg) + dict_len, 0, pad_len);
-	msg->len = sizeof(struct printk_log) + text_len + dict_len + pad_len;
-
-	/* insert message */
-	printk_log_next_idx += msg->len;
-	printk_log_next_seq++;
-}
-
 /* /dev/kmsg - userspace message inject/listen interface */
 struct devkmsg_user {
 	u64 seq;
diff --git a/kernel/printk/printk_log.c b/kernel/printk/printk_log.c
new file mode 100644
index 0000000..b5c2b8f
--- /dev/null
+++ b/kernel/printk/printk_log.c
@@ -0,0 +1,149 @@
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/sched.h>
+#include <linux/kexec.h>
+
+#include "printk_log.h"
+
+/*
+ * The printk_logbuf_lock protects kmsg buffer, indices, counters. It is also
+ * used in interesting ways to provide interlocking in console_unlock();
+ */
+DEFINE_RAW_SPINLOCK(printk_logbuf_lock);
+
+#ifdef CONFIG_PRINTK
+
+/* index and sequence number of the first record stored in the buffer */
+u64 printk_log_first_seq;
+u32 printk_log_first_idx;
+
+/* index and sequence number of the next record to store in the buffer */
+u64 printk_log_next_seq;
+u32 printk_log_next_idx;
+
+/* the next printk record to read after the last 'clear' command */
+u64 printk_log_clear_seq;
+u32 printk_log_clear_idx;
+
+/* record buffer */
+char __printk_log_buf[__PRINTK_LOG_BUF_LEN] __aligned(PRINTK_LOG_ALIGN);
+char *printk_log_buf = __printk_log_buf;
+u32 printk_log_buf_len = __PRINTK_LOG_BUF_LEN;
+
+/* human readable text of the record */
+char *printk_log_text(const struct printk_log *msg)
+{
+	return (char *)msg + sizeof(struct printk_log);
+}
+
+/* optional key/value pair dictionary attached to the record */
+char *printk_log_dict(const struct printk_log *msg)
+{
+	return (char *)msg + sizeof(struct printk_log) + msg->text_len;
+}
+
+/* get record by index; idx must point to valid msg */
+struct printk_log *printk_log_from_idx(u32 idx)
+{
+	struct printk_log *msg = (struct printk_log *)(printk_log_buf + idx);
+
+	/*
+	 * A length == 0 record is the end of buffer marker. Wrap around and
+	 * read the message at the start of the buffer.
+	 */
+	if (!msg->len)
+		return (struct printk_log *)printk_log_buf;
+	return msg;
+}
+
+/* get next record; idx must point to valid msg */
+u32 printk_log_next(u32 idx)
+{
+	struct printk_log *msg = (struct printk_log *)(printk_log_buf + idx);
+
+	/* length == 0 indicates the end of the buffer; wrap */
+	/*
+	 * A length == 0 record is the end of buffer marker. Wrap around and
+	 * read the message at the start of the buffer as *this* one, and
+	 * return the one after that.
+	 */
+	if (!msg->len) {
+		msg = (struct printk_log *)printk_log_buf;
+		return msg->len;
+	}
+	return idx + msg->len;
+}
+
+/* insert record into the buffer, discard old ones, update heads */
+void printk_log_store(int facility, int level,
+		      enum printk_log_flags flags, u64 ts_nsec,
+		      const char *dict, u16 dict_len,
+		      const char *text, u16 text_len)
+{
+	struct printk_log *msg;
+	u32 size, pad_len;
+
+	/* number of '\0' padding bytes to next message */
+	size = sizeof(struct printk_log) + text_len + dict_len;
+	pad_len = (-size) & (PRINTK_LOG_ALIGN - 1);
+	size += pad_len;
+
+	while (printk_log_first_seq < printk_log_next_seq) {
+		u32 free;
+
+		if (printk_log_next_idx > printk_log_first_idx)
+			free = max(printk_log_buf_len - printk_log_next_idx, printk_log_first_idx);
+		else
+			free = printk_log_first_idx - printk_log_next_idx;
+
+		if (free > size + sizeof(struct printk_log))
+			break;
+
+		/* drop old messages until we have enough contiuous space */
+		printk_log_first_idx = printk_log_next(printk_log_first_idx);
+		printk_log_first_seq++;
+	}
+
+	if (printk_log_next_idx + size + sizeof(struct printk_log) >= printk_log_buf_len) {
+		/*
+		 * This message + an additional empty header does not fit
+		 * at the end of the buffer. Add an empty header with len == 0
+		 * to signify a wrap around.
+		 */
+		memset(printk_log_buf + printk_log_next_idx, 0, sizeof(struct printk_log));
+		printk_log_next_idx = 0;
+	}
+
+	/* fill message */
+	msg = (struct printk_log *)(printk_log_buf + printk_log_next_idx);
+	memcpy(printk_log_text(msg), text, text_len);
+	msg->text_len = text_len;
+	memcpy(printk_log_dict(msg), dict, dict_len);
+	msg->dict_len = dict_len;
+	msg->facility = facility;
+	msg->level = level & 7;
+	msg->flags = flags & 0x1f;
+	if (ts_nsec > 0)
+		msg->ts_nsec = ts_nsec;
+	else
+		msg->ts_nsec = local_clock();
+	memset(printk_log_dict(msg) + dict_len, 0, pad_len);
+	msg->len = sizeof(struct printk_log) + text_len + dict_len + pad_len;
+
+	/* insert message */
+	printk_log_next_idx += msg->len;
+	printk_log_next_seq++;
+}
+
+#else /* CONFIG_PRINTK */
+
+#define LOG_LINE_MAX		0
+#define PREFIX_MAX		0
+#define LOG_LINE_MAX 0
+u64 printk_log_first_seq;
+u32 printk_log_first_idx;
+u64 printk_log_next_seq;
+struct printk_log *printk_log_from_idx(u32 idx) { return NULL; }
+u32 printk_log_next(u32 idx) { return 0; }
+
+#endif /* CONFIG_PRINTK */
-- 
1.7.8.112.g3fd21

[PATCH V2 17/23] printk: Make wait_queue_head_t printk_log_wait extern

[Joe Perches]

Move the variable to the .h file too.

Signed-off-by: Joe Perches <joe@perches.com>
---
 kernel/printk/printk_log.h |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/kernel/printk/printk_log.h b/kernel/printk/printk_log.h
index 0327f8d..e846f1d 100644
--- a/kernel/printk/printk_log.h
+++ b/kernel/printk/printk_log.h
@@ -93,6 +93,7 @@ struct printk_log {
 #define __PRINTK_LOG_BUF_LEN (1 << CONFIG_LOG_BUF_SHIFT)
 
 extern raw_spinlock_t printk_logbuf_lock;
+extern wait_queue_head_t printk_log_wait;
 extern u64 printk_log_first_seq;
 extern u32 printk_log_first_idx;
 extern u64 printk_log_next_seq;
-- 
1.7.8.112.g3fd21

[PATCH V2 18/23] printk: Rename and move 2 #defines to printk_log.h

[Joe Perches]

Rename the LOG_LINE_MAX and PREFIX_MAX #defines with PRINTK_ prefixes.
Move the defines to printk_log.h
Remove duplicate define too.

Fixed redefined PRINTK_LOG_LINE_MAX and PRINTK_PREFIX_MAX.

Reported-by: Yuanhan Liu <yuanhan.liu@intel.com>
Signed-off-by: Joe Perches <joe@perches.com>
---
 kernel/printk/printk.c     |   22 ++++++++--------------
 kernel/printk/printk_log.h |    8 ++++++++
 2 files changed, 16 insertions(+), 14 deletions(-)

diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 3b5c10e..988d048 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -133,9 +133,6 @@ static u64 console_seq;
 static u32 console_idx;
 static enum printk_log_flags console_prev;
 
-#define PREFIX_MAX		32
-#define LOG_LINE_MAX		1024 - PREFIX_MAX
-
 /* cpu currently holding printk_logbuf_lock */
 static volatile unsigned int logbuf_cpu = UINT_MAX;
 
@@ -158,7 +155,7 @@ static ssize_t devkmsg_writev(struct kiocb *iocb, const struct iovec *iv,
 	size_t len = iov_length(iv, count);
 	ssize_t ret = len;
 
-	if (len > LOG_LINE_MAX)
+	if (len > PRINTK_LOG_LINE_MAX)
 		return -EINVAL;
 	buf = kmalloc(len+1, GFP_KERNEL);
 	if (buf == NULL)
@@ -721,7 +718,7 @@ static int syslog_print(char __user *buf, int size)
 	struct printk_log *msg;
 	int len = 0;
 
-	text = kmalloc(LOG_LINE_MAX + PREFIX_MAX, GFP_KERNEL);
+	text = kmalloc(PRINTK_LOG_LINE_MAX + PRINTK_PREFIX_MAX, GFP_KERNEL);
 	if (!text)
 		return -ENOMEM;
 
@@ -745,7 +742,7 @@ static int syslog_print(char __user *buf, int size)
 		skip = syslog_partial;
 		msg = printk_log_from_idx(syslog_idx);
 		n = msg_print_text(msg, syslog_prev, true, text,
-				   LOG_LINE_MAX + PREFIX_MAX);
+				   PRINTK_LOG_LINE_MAX + PRINTK_PREFIX_MAX);
 		if (n - syslog_partial <= size) {
 			/* message fits into buffer, move forward */
 			syslog_idx = printk_log_next(syslog_idx);
@@ -784,7 +781,7 @@ static int syslog_print_all(char __user *buf, int size, bool clear)
 	char *text;
 	int len = 0;
 
-	text = kmalloc(LOG_LINE_MAX + PREFIX_MAX, GFP_KERNEL);
+	text = kmalloc(PRINTK_LOG_LINE_MAX + PRINTK_PREFIX_MAX, GFP_KERNEL);
 	if (!text)
 		return -ENOMEM;
 
@@ -840,7 +837,7 @@ static int syslog_print_all(char __user *buf, int size, bool clear)
 			int textlen;
 
 			textlen = msg_print_text(msg, prev, true, text,
-						 LOG_LINE_MAX + PREFIX_MAX);
+						 PRINTK_LOG_LINE_MAX + PRINTK_PREFIX_MAX);
 			if (textlen < 0) {
 				len = textlen;
 				break;
@@ -1160,7 +1157,7 @@ static inline void printk_delay(void)
  * reached the console in case of a kernel crash.
  */
 static struct cont {
-	char buf[LOG_LINE_MAX];
+	char buf[PRINTK_LOG_LINE_MAX];
 	size_t len;			/* length == 0 means unused buffer */
 	size_t cons;			/* bytes written to console */
 	struct task_struct *owner;	/* task of first print*/
@@ -1262,7 +1259,7 @@ asmlinkage int vprintk_emit(int facility, int level,
 			    const char *fmt, va_list args)
 {
 	static int recursion_bug;
-	static char textbuf[LOG_LINE_MAX];
+	static char textbuf[PRINTK_LOG_LINE_MAX];
 	char *text = textbuf;
 	size_t text_len;
 	enum printk_log_flags lflags = 0;
@@ -1465,9 +1462,6 @@ EXPORT_SYMBOL(printk);
 
 #else /* CONFIG_PRINTK */
 
-#define LOG_LINE_MAX		0
-#define PREFIX_MAX		0
-#define LOG_LINE_MAX 0
 static u64 syslog_seq;
 static u32 syslog_idx;
 static u64 console_seq;
@@ -1793,7 +1787,7 @@ out:
  */
 void console_unlock(void)
 {
-	static char text[LOG_LINE_MAX + PREFIX_MAX];
+	static char text[PRINTK_LOG_LINE_MAX + PRINTK_PREFIX_MAX];
 	static u64 seen_seq;
 	unsigned long flags;
 	bool wake_klogd = false;
diff --git a/kernel/printk/printk_log.h b/kernel/printk/printk_log.h
index e846f1d..724b6e0 100644
--- a/kernel/printk/printk_log.h
+++ b/kernel/printk/printk_log.h
@@ -92,6 +92,14 @@ struct printk_log {
 #endif
 #define __PRINTK_LOG_BUF_LEN (1 << CONFIG_LOG_BUF_SHIFT)
 
+#ifdef CONFIG_PRINTK
+#define PRINTK_PREFIX_MAX	32
+#define PRINTK_LOG_LINE_MAX	(1024 - PRINTK_PREFIX_MAX)
+#else
+#define PRINTK_LOG_LINE_MAX	0
+#define PRINTK_PREFIX_MAX	0
+#endif
+
 extern raw_spinlock_t printk_logbuf_lock;
 extern wait_queue_head_t printk_log_wait;
 extern u64 printk_log_first_seq;
-- 
1.7.8.112.g3fd21

[PATCH V2 19/23] printk: Move devkmsg bits to separate file

[Joe Perches]

Move the devkmsg_ functions and kmsg_fops declaration
to devkmsg.c.

Add devkmsg.o to Makefile.

Signed-off-by: Joe Perches <joe@perches.com>
---
 kernel/printk/Makefile  |    1 +
 kernel/printk/devkmsg.c |  309 +++++++++++++++++++++++++++++++++++++++++++++++
 kernel/printk/printk.c  |  296 ---------------------------------------------
 3 files changed, 310 insertions(+), 296 deletions(-)
 create mode 100644 kernel/printk/devkmsg.c

diff --git a/kernel/printk/Makefile b/kernel/printk/Makefile
index a692b68..bda335f 100644
--- a/kernel/printk/Makefile
+++ b/kernel/printk/Makefile
@@ -1,3 +1,4 @@
 obj-y	= printk.o
 obj-y	+= printk_log.o
+obj-y	+= devkmsg.o
 obj-$(CONFIG_A11Y_BRAILLE_CONSOLE)	+= braille.o
diff --git a/kernel/printk/devkmsg.c b/kernel/printk/devkmsg.c
new file mode 100644
index 0000000..af83290
--- /dev/null
+++ b/kernel/printk/devkmsg.c
@@ -0,0 +1,309 @@
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/kexec.h>
+#include <linux/slab.h>
+#include <linux/security.h>
+#include <linux/uaccess.h>
+#include <linux/poll.h>
+#include <linux/syslog.h>
+#include <linux/wait.h>
+#include <linux/uio.h>
+#include <linux/sched.h>
+
+#include "printk_log.h"
+
+/* /dev/kmsg - userspace message inject/listen interface */
+struct devkmsg_user {
+	u64 seq;
+	u32 idx;
+	enum printk_log_flags prev;
+	struct mutex lock;
+	char buf[8192];
+};
+
+static ssize_t devkmsg_writev(struct kiocb *iocb, const struct iovec *iv,
+			      unsigned long count, loff_t pos)
+{
+	char *buf, *line;
+	int i;
+	int level = default_message_loglevel;
+	int facility = 1;	/* LOG_USER */
+	size_t len = iov_length(iv, count);
+	ssize_t ret = len;
+
+	if (len > PRINTK_LOG_LINE_MAX)
+		return -EINVAL;
+	buf = kmalloc(len+1, GFP_KERNEL);
+	if (buf == NULL)
+		return -ENOMEM;
+
+	line = buf;
+	for (i = 0; i < count; i++) {
+		if (copy_from_user(line, iv[i].iov_base, iv[i].iov_len)) {
+			ret = -EFAULT;
+			goto out;
+		}
+		line += iv[i].iov_len;
+	}
+
+	/*
+	 * Extract and skip the syslog prefix <[0-9]*>. Coming from userspace
+	 * the decimal value represents 32bit, the lower 3 bit are the log
+	 * level, the rest are the log facility.
+	 *
+	 * If no prefix or no userspace facility is specified, we
+	 * enforce LOG_USER, to be able to reliably distinguish
+	 * kernel-generated messages from userspace-injected ones.
+	 */
+	line = buf;
+	if (line[0] == '<') {
+		char *endp = NULL;
+
+		i = simple_strtoul(line+1, &endp, 10);
+		if (endp && endp[0] == '>') {
+			level = i & 7;
+			if (i >> 3)
+				facility = i >> 3;
+			endp++;
+			len -= endp - line;
+			line = endp;
+		}
+	}
+	line[len] = '\0';
+
+	printk_emit(facility, level, NULL, 0, "%s", line);
+out:
+	kfree(buf);
+	return ret;
+}
+
+static ssize_t devkmsg_read(struct file *file, char __user *buf,
+			    size_t count, loff_t *ppos)
+{
+	struct devkmsg_user *user = file->private_data;
+	struct printk_log *msg;
+	u64 ts_usec;
+	size_t i;
+	char cont = '-';
+	size_t len;
+	ssize_t ret;
+
+	if (!user)
+		return -EBADF;
+
+	ret = mutex_lock_interruptible(&user->lock);
+	if (ret)
+		return ret;
+	raw_spin_lock_irq(&printk_logbuf_lock);
+	while (user->seq == printk_log_next_seq) {
+		if (file->f_flags & O_NONBLOCK) {
+			ret = -EAGAIN;
+			raw_spin_unlock_irq(&printk_logbuf_lock);
+			goto out;
+		}
+
+		raw_spin_unlock_irq(&printk_logbuf_lock);
+		ret = wait_event_interruptible(printk_log_wait,
+					       user->seq != printk_log_next_seq);
+		if (ret)
+			goto out;
+		raw_spin_lock_irq(&printk_logbuf_lock);
+	}
+
+	if (user->seq < printk_log_first_seq) {
+		/* our last seen message is gone, return error and reset */
+		user->idx = printk_log_first_idx;
+		user->seq = printk_log_first_seq;
+		ret = -EPIPE;
+		raw_spin_unlock_irq(&printk_logbuf_lock);
+		goto out;
+	}
+
+	msg = printk_log_from_idx(user->idx);
+	ts_usec = msg->ts_nsec;
+	do_div(ts_usec, 1000);
+
+	/*
+	 * If we couldn't merge continuation line fragments during the print,
+	 * export the stored flags to allow an optional external merge of the
+	 * records. Merging the records isn't always neccessarily correct, like
+	 * when we hit a race during printing. In most cases though, it produces
+	 * better readable output. 'c' in the record flags mark the first
+	 * fragment of a line, '+' the following.
+	 */
+	if (msg->flags & LOG_CONT && !(user->prev & LOG_CONT))
+		cont = 'c';
+	else if ((msg->flags & LOG_CONT) ||
+		 ((user->prev & LOG_CONT) && !(msg->flags & LOG_PREFIX)))
+		cont = '+';
+
+	len = sprintf(user->buf, "%u,%llu,%llu,%c;",
+		      (msg->facility << 3) | msg->level,
+		      user->seq, ts_usec, cont);
+	user->prev = msg->flags;
+
+	/* escape non-printable characters */
+	for (i = 0; i < msg->text_len; i++) {
+		unsigned char c = printk_log_text(msg)[i];
+
+		if (c < ' ' || c >= 127 || c == '\\')
+			len += sprintf(user->buf + len, "\\x%02x", c);
+		else
+			user->buf[len++] = c;
+	}
+	user->buf[len++] = '\n';
+
+	if (msg->dict_len) {
+		bool line = true;
+
+		for (i = 0; i < msg->dict_len; i++) {
+			unsigned char c = printk_log_dict(msg)[i];
+
+			if (line) {
+				user->buf[len++] = ' ';
+				line = false;
+			}
+
+			if (c == '\0') {
+				user->buf[len++] = '\n';
+				line = true;
+				continue;
+			}
+
+			if (c < ' ' || c >= 127 || c == '\\') {
+				len += sprintf(user->buf + len, "\\x%02x", c);
+				continue;
+			}
+
+			user->buf[len++] = c;
+		}
+		user->buf[len++] = '\n';
+	}
+
+	user->idx = printk_log_next(user->idx);
+	user->seq++;
+	raw_spin_unlock_irq(&printk_logbuf_lock);
+
+	if (len > count) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	if (copy_to_user(buf, user->buf, len)) {
+		ret = -EFAULT;
+		goto out;
+	}
+	ret = len;
+out:
+	mutex_unlock(&user->lock);
+	return ret;
+}
+
+static loff_t devkmsg_llseek(struct file *file, loff_t offset, int whence)
+{
+	struct devkmsg_user *user = file->private_data;
+	loff_t ret = 0;
+
+	if (!user)
+		return -EBADF;
+	if (offset)
+		return -ESPIPE;
+
+	raw_spin_lock_irq(&printk_logbuf_lock);
+	switch (whence) {
+	case SEEK_SET:
+		/* the first record */
+		user->idx = printk_log_first_idx;
+		user->seq = printk_log_first_seq;
+		break;
+	case SEEK_DATA:
+		/*
+		 * The first record after the last SYSLOG_ACTION_CLEAR,
+		 * like issued by 'dmesg -c'. Reading /dev/kmsg itself
+		 * changes no global state, and does not clear anything.
+		 */
+		user->idx = printk_log_clear_idx;
+		user->seq = printk_log_clear_seq;
+		break;
+	case SEEK_END:
+		/* after the last record */
+		user->idx = printk_log_next_idx;
+		user->seq = printk_log_next_seq;
+		break;
+	default:
+		ret = -EINVAL;
+	}
+	raw_spin_unlock_irq(&printk_logbuf_lock);
+	return ret;
+}
+
+static unsigned int devkmsg_poll(struct file *file, poll_table *wait)
+{
+	struct devkmsg_user *user = file->private_data;
+	int ret = 0;
+
+	if (!user)
+		return POLLERR|POLLNVAL;
+
+	poll_wait(file, &printk_log_wait, wait);
+
+	raw_spin_lock_irq(&printk_logbuf_lock);
+	if (user->seq < printk_log_next_seq) {
+		/* return error when data has vanished underneath us */
+		if (user->seq < printk_log_first_seq)
+			ret = POLLIN|POLLRDNORM|POLLERR|POLLPRI;
+		ret = POLLIN|POLLRDNORM;
+	}
+	raw_spin_unlock_irq(&printk_logbuf_lock);
+
+	return ret;
+}
+
+static int devkmsg_open(struct inode *inode, struct file *file)
+{
+	struct devkmsg_user *user;
+	int err;
+
+	/* write-only does not need any file context */
+	if ((file->f_flags & O_ACCMODE) == O_WRONLY)
+		return 0;
+
+	err = security_syslog(SYSLOG_ACTION_READ_ALL);
+	if (err)
+		return err;
+
+	user = kmalloc(sizeof(struct devkmsg_user), GFP_KERNEL);
+	if (!user)
+		return -ENOMEM;
+
+	mutex_init(&user->lock);
+
+	raw_spin_lock_irq(&printk_logbuf_lock);
+	user->idx = printk_log_first_idx;
+	user->seq = printk_log_first_seq;
+	raw_spin_unlock_irq(&printk_logbuf_lock);
+
+	file->private_data = user;
+	return 0;
+}
+
+static int devkmsg_release(struct inode *inode, struct file *file)
+{
+	struct devkmsg_user *user = file->private_data;
+
+	if (!user)
+		return 0;
+
+	mutex_destroy(&user->lock);
+	kfree(user);
+	return 0;
+}
+
+const struct file_operations kmsg_fops = {
+	.open = devkmsg_open,
+	.read = devkmsg_read,
+	.aio_write = devkmsg_writev,
+	.llseek = devkmsg_llseek,
+	.poll = devkmsg_poll,
+	.release = devkmsg_release,
+};
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 988d048..5e30343 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -136,302 +136,6 @@ static enum printk_log_flags console_prev;
 /* cpu currently holding printk_logbuf_lock */
 static volatile unsigned int logbuf_cpu = UINT_MAX;
 
-/* /dev/kmsg - userspace message inject/listen interface */
-struct devkmsg_user {
-	u64 seq;
-	u32 idx;
-	enum printk_log_flags prev;
-	struct mutex lock;
-	char buf[8192];
-};
-
-static ssize_t devkmsg_writev(struct kiocb *iocb, const struct iovec *iv,
-			      unsigned long count, loff_t pos)
-{
-	char *buf, *line;
-	int i;
-	int level = default_message_loglevel;
-	int facility = 1;	/* LOG_USER */
-	size_t len = iov_length(iv, count);
-	ssize_t ret = len;
-
-	if (len > PRINTK_LOG_LINE_MAX)
-		return -EINVAL;
-	buf = kmalloc(len+1, GFP_KERNEL);
-	if (buf == NULL)
-		return -ENOMEM;
-
-	line = buf;
-	for (i = 0; i < count; i++) {
-		if (copy_from_user(line, iv[i].iov_base, iv[i].iov_len)) {
-			ret = -EFAULT;
-			goto out;
-		}
-		line += iv[i].iov_len;
-	}
-
-	/*
-	 * Extract and skip the syslog prefix <[0-9]*>. Coming from userspace
-	 * the decimal value represents 32bit, the lower 3 bit are the log
-	 * level, the rest are the log facility.
-	 *
-	 * If no prefix or no userspace facility is specified, we
-	 * enforce LOG_USER, to be able to reliably distinguish
-	 * kernel-generated messages from userspace-injected ones.
-	 */
-	line = buf;
-	if (line[0] == '<') {
-		char *endp = NULL;
-
-		i = simple_strtoul(line+1, &endp, 10);
-		if (endp && endp[0] == '>') {
-			level = i & 7;
-			if (i >> 3)
-				facility = i >> 3;
-			endp++;
-			len -= endp - line;
-			line = endp;
-		}
-	}
-	line[len] = '\0';
-
-	printk_emit(facility, level, NULL, 0, "%s", line);
-out:
-	kfree(buf);
-	return ret;
-}
-
-static ssize_t devkmsg_read(struct file *file, char __user *buf,
-			    size_t count, loff_t *ppos)
-{
-	struct devkmsg_user *user = file->private_data;
-	struct printk_log *msg;
-	u64 ts_usec;
-	size_t i;
-	char cont = '-';
-	size_t len;
-	ssize_t ret;
-
-	if (!user)
-		return -EBADF;
-
-	ret = mutex_lock_interruptible(&user->lock);
-	if (ret)
-		return ret;
-	raw_spin_lock_irq(&printk_logbuf_lock);
-	while (user->seq == printk_log_next_seq) {
-		if (file->f_flags & O_NONBLOCK) {
-			ret = -EAGAIN;
-			raw_spin_unlock_irq(&printk_logbuf_lock);
-			goto out;
-		}
-
-		raw_spin_unlock_irq(&printk_logbuf_lock);
-		ret = wait_event_interruptible(printk_log_wait,
-					       user->seq != printk_log_next_seq);
-		if (ret)
-			goto out;
-		raw_spin_lock_irq(&printk_logbuf_lock);
-	}
-
-	if (user->seq < printk_log_first_seq) {
-		/* our last seen message is gone, return error and reset */
-		user->idx = printk_log_first_idx;
-		user->seq = printk_log_first_seq;
-		ret = -EPIPE;
-		raw_spin_unlock_irq(&printk_logbuf_lock);
-		goto out;
-	}
-
-	msg = printk_log_from_idx(user->idx);
-	ts_usec = msg->ts_nsec;
-	do_div(ts_usec, 1000);
-
-	/*
-	 * If we couldn't merge continuation line fragments during the print,
-	 * export the stored flags to allow an optional external merge of the
-	 * records. Merging the records isn't always neccessarily correct, like
-	 * when we hit a race during printing. In most cases though, it produces
-	 * better readable output. 'c' in the record flags mark the first
-	 * fragment of a line, '+' the following.
-	 */
-	if (msg->flags & LOG_CONT && !(user->prev & LOG_CONT))
-		cont = 'c';
-	else if ((msg->flags & LOG_CONT) ||
-		 ((user->prev & LOG_CONT) && !(msg->flags & LOG_PREFIX)))
-		cont = '+';
-
-	len = sprintf(user->buf, "%u,%llu,%llu,%c;",
-		      (msg->facility << 3) | msg->level,
-		      user->seq, ts_usec, cont);
-	user->prev = msg->flags;
-
-	/* escape non-printable characters */
-	for (i = 0; i < msg->text_len; i++) {
-		unsigned char c = printk_log_text(msg)[i];
-
-		if (c < ' ' || c >= 127 || c == '\\')
-			len += sprintf(user->buf + len, "\\x%02x", c);
-		else
-			user->buf[len++] = c;
-	}
-	user->buf[len++] = '\n';
-
-	if (msg->dict_len) {
-		bool line = true;
-
-		for (i = 0; i < msg->dict_len; i++) {
-			unsigned char c = printk_log_dict(msg)[i];
-
-			if (line) {
-				user->buf[len++] = ' ';
-				line = false;
-			}
-
-			if (c == '\0') {
-				user->buf[len++] = '\n';
-				line = true;
-				continue;
-			}
-
-			if (c < ' ' || c >= 127 || c == '\\') {
-				len += sprintf(user->buf + len, "\\x%02x", c);
-				continue;
-			}
-
-			user->buf[len++] = c;
-		}
-		user->buf[len++] = '\n';
-	}
-
-	user->idx = printk_log_next(user->idx);
-	user->seq++;
-	raw_spin_unlock_irq(&printk_logbuf_lock);
-
-	if (len > count) {
-		ret = -EINVAL;
-		goto out;
-	}
-
-	if (copy_to_user(buf, user->buf, len)) {
-		ret = -EFAULT;
-		goto out;
-	}
-	ret = len;
-out:
-	mutex_unlock(&user->lock);
-	return ret;
-}
-
-static loff_t devkmsg_llseek(struct file *file, loff_t offset, int whence)
-{
-	struct devkmsg_user *user = file->private_data;
-	loff_t ret = 0;
-
-	if (!user)
-		return -EBADF;
-	if (offset)
-		return -ESPIPE;
-
-	raw_spin_lock_irq(&printk_logbuf_lock);
-	switch (whence) {
-	case SEEK_SET:
-		/* the first record */
-		user->idx = printk_log_first_idx;
-		user->seq = printk_log_first_seq;
-		break;
-	case SEEK_DATA:
-		/*
-		 * The first record after the last SYSLOG_ACTION_CLEAR,
-		 * like issued by 'dmesg -c'. Reading /dev/kmsg itself
-		 * changes no global state, and does not clear anything.
-		 */
-		user->idx = printk_log_clear_idx;
-		user->seq = printk_log_clear_seq;
-		break;
-	case SEEK_END:
-		/* after the last record */
-		user->idx = printk_log_next_idx;
-		user->seq = printk_log_next_seq;
-		break;
-	default:
-		ret = -EINVAL;
-	}
-	raw_spin_unlock_irq(&printk_logbuf_lock);
-	return ret;
-}
-
-static unsigned int devkmsg_poll(struct file *file, poll_table *wait)
-{
-	struct devkmsg_user *user = file->private_data;
-	int ret = 0;
-
-	if (!user)
-		return POLLERR|POLLNVAL;
-
-	poll_wait(file, &printk_log_wait, wait);
-
-	raw_spin_lock_irq(&printk_logbuf_lock);
-	if (user->seq < printk_log_next_seq) {
-		/* return error when data has vanished underneath us */
-		if (user->seq < printk_log_first_seq)
-			ret = POLLIN|POLLRDNORM|POLLERR|POLLPRI;
-		ret = POLLIN|POLLRDNORM;
-	}
-	raw_spin_unlock_irq(&printk_logbuf_lock);
-
-	return ret;
-}
-
-static int devkmsg_open(struct inode *inode, struct file *file)
-{
-	struct devkmsg_user *user;
-	int err;
-
-	/* write-only does not need any file context */
-	if ((file->f_flags & O_ACCMODE) == O_WRONLY)
-		return 0;
-
-	err = security_syslog(SYSLOG_ACTION_READ_ALL);
-	if (err)
-		return err;
-
-	user = kmalloc(sizeof(struct devkmsg_user), GFP_KERNEL);
-	if (!user)
-		return -ENOMEM;
-
-	mutex_init(&user->lock);
-
-	raw_spin_lock_irq(&printk_logbuf_lock);
-	user->idx = printk_log_first_idx;
-	user->seq = printk_log_first_seq;
-	raw_spin_unlock_irq(&printk_logbuf_lock);
-
-	file->private_data = user;
-	return 0;
-}
-
-static int devkmsg_release(struct inode *inode, struct file *file)
-{
-	struct devkmsg_user *user = file->private_data;
-
-	if (!user)
-		return 0;
-
-	mutex_destroy(&user->lock);
-	kfree(user);
-	return 0;
-}
-
-const struct file_operations kmsg_fops = {
-	.open = devkmsg_open,
-	.read = devkmsg_read,
-	.aio_write = devkmsg_writev,
-	.llseek = devkmsg_llseek,
-	.poll = devkmsg_poll,
-	.release = devkmsg_release,
-};
-
 #ifdef CONFIG_KEXEC
 /*
  * This appends the listed symbols to /proc/vmcoreinfo
-- 
1.7.8.112.g3fd21

[PATCH V2 20/23] printk: Prefix print_time and msg_print_text with printk_

[Joe Perches]

Make these static functions global and prefix them with printk_.
Create declarations for these functions in printk_log.h

Signed-off-by: Joe Perches <joe@perches.com>
---
 kernel/printk/printk.c     |   43 ++++++++++++++++++++++++-------------------
 kernel/printk/printk_log.h |    4 ++++
 2 files changed, 28 insertions(+), 19 deletions(-)

diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 5e30343..b671523 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -318,7 +318,7 @@ static bool printk_time;
 #endif
 module_param_named(time, printk_time, bool, S_IRUGO | S_IWUSR);
 
-static size_t print_time(u64 ts, char *buf)
+size_t printk_print_time(u64 ts, char *buf)
 {
 	unsigned long rem_nsec;
 
@@ -352,11 +352,11 @@ static size_t print_prefix(const struct printk_log *msg, bool syslog, char *buf)
 		}
 	}
 
-	len += print_time(msg->ts_nsec, buf ? buf + len : NULL);
+	len += printk_print_time(msg->ts_nsec, buf ? buf + len : NULL);
 	return len;
 }
 
-static size_t msg_print_text(const struct printk_log *msg,
+size_t printk_msg_print_text(const struct printk_log *msg,
 			     enum printk_log_flags prev,
 			     bool syslog, char *buf, size_t size)
 {
@@ -445,8 +445,8 @@ static int syslog_print(char __user *buf, int size)
 
 		skip = syslog_partial;
 		msg = printk_log_from_idx(syslog_idx);
-		n = msg_print_text(msg, syslog_prev, true, text,
-				   PRINTK_LOG_LINE_MAX + PRINTK_PREFIX_MAX);
+		n = printk_msg_print_text(msg, syslog_prev, true, text,
+					  PRINTK_LOG_LINE_MAX + PRINTK_PREFIX_MAX);
 		if (n - syslog_partial <= size) {
 			/* message fits into buffer, move forward */
 			syslog_idx = printk_log_next(syslog_idx);
@@ -512,7 +512,7 @@ static int syslog_print_all(char __user *buf, int size, bool clear)
 		while (seq < printk_log_next_seq) {
 			struct printk_log *msg = printk_log_from_idx(idx);
 
-			len += msg_print_text(msg, prev, true, NULL, 0);
+			len += printk_msg_print_text(msg, prev, true, NULL, 0);
 			prev = msg->flags;
 			idx = printk_log_next(idx);
 			seq++;
@@ -525,7 +525,7 @@ static int syslog_print_all(char __user *buf, int size, bool clear)
 		while (len > size && seq < printk_log_next_seq) {
 			struct printk_log *msg = printk_log_from_idx(idx);
 
-			len -= msg_print_text(msg, prev, true, NULL, 0);
+			len -= printk_msg_print_text(msg, prev, true, NULL, 0);
 			prev = msg->flags;
 			idx = printk_log_next(idx);
 			seq++;
@@ -540,8 +540,8 @@ static int syslog_print_all(char __user *buf, int size, bool clear)
 			struct printk_log *msg = printk_log_from_idx(idx);
 			int textlen;
 
-			textlen = msg_print_text(msg, prev, true, text,
-						 PRINTK_LOG_LINE_MAX + PRINTK_PREFIX_MAX);
+			textlen = printk_msg_print_text(msg, prev, true, text,
+							PRINTK_LOG_LINE_MAX + PRINTK_PREFIX_MAX);
 			if (textlen < 0) {
 				len = textlen;
 				break;
@@ -685,7 +685,7 @@ int do_syslog(int type, char __user *buf, int len, bool from_file)
 			while (seq < printk_log_next_seq) {
 				struct printk_log *msg = printk_log_from_idx(idx);
 
-				error += msg_print_text(msg, prev, true, NULL, 0);
+				error += printk_msg_print_text(msg, prev, true, NULL, 0);
 				idx = printk_log_next(idx);
 				seq++;
 				prev = msg->flags;
@@ -936,7 +936,7 @@ static size_t cont_print_text(char *text, size_t size)
 	size_t len;
 
 	if (cont.cons == 0 && (console_prev & LOG_NEWLINE)) {
-		textlen += print_time(cont.ts_nsec, text);
+		textlen += printk_print_time(cont.ts_nsec, text);
 		size -= textlen;
 	}
 
@@ -1184,9 +1184,14 @@ static struct cont {
 struct printk_log *printk_log_from_idx(u32 idx) { return NULL; }
 u32 printk_log_next(u32 idx) { return 0; }
 static void call_console_drivers(int level, const char *text, size_t len) {}
-static size_t msg_print_text(const struct printk_log *msg,
+size_t printk_print_time(u64 ts, char *buf) { return 0; }
+size_t printk_msg_print_text(const struct printk_log *msg,
 			     enum printk_log_flags prev,
-			     bool syslog, char *buf, size_t size) { return 0; }
+			     bool syslog, char *buf, size_t size)
+{
+	return 0;
+}
+
 static size_t cont_print_text(char *text, size_t size) { return 0; }
 
 #endif /* CONFIG_PRINTK */
@@ -1547,8 +1552,8 @@ skip:
 		}
 
 		level = msg->level;
-		len = msg_print_text(msg, console_prev, false,
-				     text, sizeof(text));
+		len = printk_msg_print_text(msg, console_prev, false,
+					    text, sizeof(text));
 		console_idx = printk_log_next(console_idx);
 		console_seq++;
 		console_prev = msg->flags;
@@ -2102,7 +2107,7 @@ bool kmsg_dump_get_line_nolock(struct kmsg_dumper *dumper, bool syslog,
 		goto out;
 
 	msg = printk_log_from_idx(dumper->cur_idx);
-	l = msg_print_text(msg, 0, syslog, line, size);
+	l = printk_msg_print_text(msg, 0, syslog, line, size);
 
 	dumper->cur_idx = printk_log_next(dumper->cur_idx);
 	dumper->cur_seq++;
@@ -2198,7 +2203,7 @@ bool kmsg_dump_get_buffer(struct kmsg_dumper *dumper, bool syslog,
 	while (seq < dumper->next_seq) {
 		struct printk_log *msg = printk_log_from_idx(idx);
 
-		l += msg_print_text(msg, prev, true, NULL, 0);
+		l += printk_msg_print_text(msg, prev, true, NULL, 0);
 		idx = printk_log_next(idx);
 		seq++;
 		prev = msg->flags;
@@ -2211,7 +2216,7 @@ bool kmsg_dump_get_buffer(struct kmsg_dumper *dumper, bool syslog,
 	while (l > size && seq < dumper->next_seq) {
 		struct printk_log *msg = printk_log_from_idx(idx);
 
-		l -= msg_print_text(msg, prev, true, NULL, 0);
+		l -= printk_msg_print_text(msg, prev, true, NULL, 0);
 		idx = printk_log_next(idx);
 		seq++;
 		prev = msg->flags;
@@ -2226,7 +2231,7 @@ bool kmsg_dump_get_buffer(struct kmsg_dumper *dumper, bool syslog,
 	while (seq < dumper->next_seq) {
 		struct printk_log *msg = printk_log_from_idx(idx);
 
-		l += msg_print_text(msg, prev, syslog, buf + l, size - l);
+		l += printk_msg_print_text(msg, prev, syslog, buf + l, size - l);
 		idx = printk_log_next(idx);
 		seq++;
 		prev = msg->flags;
diff --git a/kernel/printk/printk_log.h b/kernel/printk/printk_log.h
index 724b6e0..4c2df51 100644
--- a/kernel/printk/printk_log.h
+++ b/kernel/printk/printk_log.h
@@ -120,5 +120,9 @@ void printk_log_store(int facility, int level,
 		      enum printk_log_flags flags, u64 ts_nsec,
 		      const char *dict, u16 dict_len,
 		      const char *text, u16 text_len);
+size_t printk_print_time(u64 ts, char *buf);
+size_t printk_msg_print_text(const struct printk_log *msg,
+			     enum printk_log_flags prev,
+			     bool syslog, char *buf, size_t size);
 
 #endif
-- 
1.7.8.112.g3fd21

[PATCH V2 21/23] printk: Move functions printk_print_time and printk_msg_print_text

[Joe Perches]

Move these functions to printk_log.
Move the static function print_prefix too.
Add "#include <linux/moduleparam.h>" to printk_log.c.

Signed-off-by: Joe Perches <joe@perches.com>
---
 kernel/printk/printk.c     |  112 -------------------------------------------
 kernel/printk/printk_log.c |  114 ++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 114 insertions(+), 112 deletions(-)

diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index b671523..0c6042a 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -311,111 +311,6 @@ static int check_syslog_permissions(int type, bool from_file)
 	return 0;
 }
 
-#if defined(CONFIG_PRINTK_TIME)
-static bool printk_time = 1;
-#else
-static bool printk_time;
-#endif
-module_param_named(time, printk_time, bool, S_IRUGO | S_IWUSR);
-
-size_t printk_print_time(u64 ts, char *buf)
-{
-	unsigned long rem_nsec;
-
-	if (!printk_time)
-		return 0;
-
-	if (!buf)
-		return 15;
-
-	rem_nsec = do_div(ts, 1000000000);
-	return sprintf(buf, "[%5lu.%06lu] ",
-		       (unsigned long)ts, rem_nsec / 1000);
-}
-
-static size_t print_prefix(const struct printk_log *msg, bool syslog, char *buf)
-{
-	size_t len = 0;
-	unsigned int prefix = (msg->facility << 3) | msg->level;
-
-	if (syslog) {
-		if (buf) {
-			len += sprintf(buf, "<%u>", prefix);
-		} else {
-			len += 3;
-			if (prefix > 999)
-				len += 3;
-			else if (prefix > 99)
-				len += 2;
-			else if (prefix > 9)
-				len++;
-		}
-	}
-
-	len += printk_print_time(msg->ts_nsec, buf ? buf + len : NULL);
-	return len;
-}
-
-size_t printk_msg_print_text(const struct printk_log *msg,
-			     enum printk_log_flags prev,
-			     bool syslog, char *buf, size_t size)
-{
-	const char *text = printk_log_text(msg);
-	size_t text_size = msg->text_len;
-	bool prefix = true;
-	bool newline = true;
-	size_t len = 0;
-
-	if ((prev & LOG_CONT) && !(msg->flags & LOG_PREFIX))
-		prefix = false;
-
-	if (msg->flags & LOG_CONT) {
-		if ((prev & LOG_CONT) && !(prev & LOG_NEWLINE))
-			prefix = false;
-
-		if (!(msg->flags & LOG_NEWLINE))
-			newline = false;
-	}
-
-	do {
-		const char *next = memchr(text, '\n', text_size);
-		size_t text_len;
-
-		if (next) {
-			text_len = next - text;
-			next++;
-			text_size -= next - text;
-		} else {
-			text_len = text_size;
-		}
-
-		if (buf) {
-			if (print_prefix(msg, syslog, NULL) +
-			    text_len + 1 >= size - len)
-				break;
-
-			if (prefix)
-				len += print_prefix(msg, syslog, buf + len);
-			memcpy(buf + len, text, text_len);
-			len += text_len;
-			if (next || newline)
-				buf[len++] = '\n';
-		} else {
-			/* SYSLOG_ACTION_* buffer size only calculation */
-			if (prefix)
-				len += print_prefix(msg, syslog, NULL);
-			len += text_len;
-			if (next || newline)
-				len++;
-		}
-
-		prefix = true;
-		text = next;
-	} while (text);
-
-	return len;
-}
-
 static int syslog_print(char __user *buf, int size)
 {
 	char *text;
@@ -1184,13 +1079,6 @@ static struct cont {
 struct printk_log *printk_log_from_idx(u32 idx) { return NULL; }
 u32 printk_log_next(u32 idx) { return 0; }
 static void call_console_drivers(int level, const char *text, size_t len) {}
-size_t printk_print_time(u64 ts, char *buf) { return 0; }
-size_t printk_msg_print_text(const struct printk_log *msg,
-			     enum printk_log_flags prev,
-			     bool syslog, char *buf, size_t size)
-{
-	return 0;
-}
 
 static size_t cont_print_text(char *text, size_t size) { return 0; }
 
diff --git a/kernel/printk/printk_log.c b/kernel/printk/printk_log.c
index b5c2b8f..d38129c 100644
--- a/kernel/printk/printk_log.c
+++ b/kernel/printk/printk_log.c
@@ -2,6 +2,8 @@
 #include <linux/mm.h>
 #include <linux/sched.h>
 #include <linux/kexec.h>
+#include <linux/moduleparam.h>
+#include <linux/stat.h>
 
 #include "printk_log.h"
 
@@ -135,6 +137,111 @@ void printk_log_store(int facility, int level,
 	printk_log_next_seq++;
 }
 
+#if defined(CONFIG_PRINTK_TIME)
+static bool printk_time = 1;
+#else
+static bool printk_time;
+#endif
+module_param_named(time, printk_time, bool, S_IRUGO | S_IWUSR);
+
+size_t printk_print_time(u64 ts, char *buf)
+{
+	unsigned long rem_nsec;
+
+	if (!printk_time)
+		return 0;
+
+	if (!buf)
+		return 15;
+
+	rem_nsec = do_div(ts, 1000000000);
+	return sprintf(buf, "[%5lu.%06lu] ",
+		       (unsigned long)ts, rem_nsec / 1000);
+}
+
+static size_t print_prefix(const struct printk_log *msg, bool syslog, char *buf)
+{
+	size_t len = 0;
+	unsigned int prefix = (msg->facility << 3) | msg->level;
+
+	if (syslog) {
+		if (buf) {
+			len += sprintf(buf, "<%u>", prefix);
+		} else {
+			len += 3;
+			if (prefix > 999)
+				len += 3;
+			else if (prefix > 99)
+				len += 2;
+			else if (prefix > 9)
+				len++;
+		}
+	}
+
+	len += printk_print_time(msg->ts_nsec, buf ? buf + len : NULL);
+	return len;
+}
+
+size_t printk_msg_print_text(const struct printk_log *msg,
+			     enum printk_log_flags prev,
+			     bool syslog, char *buf, size_t size)
+{
+	const char *text = printk_log_text(msg);
+	size_t text_size = msg->text_len;
+	bool prefix = true;
+	bool newline = true;
+	size_t len = 0;
+
+	if ((prev & LOG_CONT) && !(msg->flags & LOG_PREFIX))
+		prefix = false;
+
+	if (msg->flags & LOG_CONT) {
+		if ((prev & LOG_CONT) && !(prev & LOG_NEWLINE))
+			prefix = false;
+
+		if (!(msg->flags & LOG_NEWLINE))
+			newline = false;
+	}
+
+	do {
+		const char *next = memchr(text, '\n', text_size);
+		size_t text_len;
+
+		if (next) {
+			text_len = next - text;
+			next++;
+			text_size -= next - text;
+		} else {
+			text_len = text_size;
+		}
+
+		if (buf) {
+			if (print_prefix(msg, syslog, NULL) +
+			    text_len + 1 >= size - len)
+				break;
+
+			if (prefix)
+				len += print_prefix(msg, syslog, buf + len);
+			memcpy(buf + len, text, text_len);
+			len += text_len;
+			if (next || newline)
+				buf[len++] = '\n';
+		} else {
+			/* SYSLOG_ACTION_* buffer size only calculation */
+			if (prefix)
+				len += print_prefix(msg, syslog, NULL);
+			len += text_len;
+			if (next || newline)
+				len++;
+		}
+
+		prefix = true;
+		text = next;
+	} while (text);
+
+	return len;
+}
+
 #else /* CONFIG_PRINTK */
 
 #define LOG_LINE_MAX		0
@@ -145,5 +252,12 @@ u32 printk_log_first_idx;
 u64 printk_log_next_seq;
 struct printk_log *printk_log_from_idx(u32 idx) { return NULL; }
 u32 printk_log_next(u32 idx) { return 0; }
+size_t printk_print_time(u64 ts, char *buf) { return 0; }
+size_t printk_msg_print_text(const struct printk_log *msg,
+			     enum printk_log_flags prev,
+			     bool syslog, char *buf, size_t size)
+{
+	return 0;
+}
 
 #endif /* CONFIG_PRINTK */
-- 
1.7.8.112.g3fd21

[PATCH V2 22/23] printk: Add printk_syslog.c and .h

[Joe Perches]

Move syslog functions to a separate file.
Add compilation unit to Makefile.
Add missing #include <linux/uaccess.h>

Reported-by: Yuanhan Liu <yuanhan.liu@intel.com>
Signed-off-by: Joe Perches <joe@perches.com>
---
 kernel/printk/Makefile        |    1 +
 kernel/printk/printk.c        |  351 +----------------------------------------
 kernel/printk/printk_syslog.c |  355 +++++++++++++++++++++++++++++++++++++++++
 kernel/printk/printk_syslog.h |   13 ++
 4 files changed, 373 insertions(+), 347 deletions(-)
 create mode 100644 kernel/printk/printk_syslog.c
 create mode 100644 kernel/printk/printk_syslog.h

diff --git a/kernel/printk/Makefile b/kernel/printk/Makefile
index bda335f..7947661 100644
--- a/kernel/printk/Makefile
+++ b/kernel/printk/Makefile
@@ -1,4 +1,5 @@
 obj-y	= printk.o
 obj-y	+= printk_log.o
 obj-y	+= devkmsg.o
+obj-y	+= printk_syslog.o
 obj-$(CONFIG_A11Y_BRAILLE_CONSOLE)	+= braille.o
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 0c6042a..bed0e7d 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -30,12 +30,10 @@
 #include <linux/security.h>
 #include <linux/bootmem.h>
 #include <linux/memblock.h>
-#include <linux/syscalls.h>
 #include <linux/kexec.h>
 #include <linux/kdb.h>
 #include <linux/ratelimit.h>
 #include <linux/kmsg_dump.h>
-#include <linux/syslog.h>
 #include <linux/cpu.h>
 #include <linux/notifier.h>
 #include <linux/rculist.h>
@@ -49,6 +47,7 @@
 #include "console_cmdline.h"
 #include "braille.h"
 #include "printk_log.h"
+#include "printk_syslog.h"
 
 /*
  * Architectures can override it:
@@ -122,11 +121,6 @@ EXPORT_SYMBOL(console_set_on_cmdline);
 static int console_may_schedule;
 
 #ifdef CONFIG_PRINTK
-/* the next printk record to read by syslog(READ) or /proc/kmsg */
-static u64 syslog_seq;
-static u32 syslog_idx;
-static enum printk_log_flags syslog_prev;
-static size_t syslog_partial;
 
 /* the next printk record to write to the console */
 static u64 console_seq;
@@ -272,340 +266,6 @@ static inline void boot_delay_msec(void)
 }
 #endif
 
-#ifdef CONFIG_SECURITY_DMESG_RESTRICT
-int dmesg_restrict = 1;
-#else
-int dmesg_restrict;
-#endif
-
-static int syslog_action_restricted(int type)
-{
-	if (dmesg_restrict)
-		return 1;
-	/* Unless restricted, we allow "read all" and "get buffer size" for everybody */
-	return type != SYSLOG_ACTION_READ_ALL && type != SYSLOG_ACTION_SIZE_BUFFER;
-}
-
-static int check_syslog_permissions(int type, bool from_file)
-{
-	/*
-	 * If this is from /proc/kmsg and we've already opened it, then we've
-	 * already done the capabilities checks at open time.
-	 */
-	if (from_file && type != SYSLOG_ACTION_OPEN)
-		return 0;
-
-	if (syslog_action_restricted(type)) {
-		if (capable(CAP_SYSLOG))
-			return 0;
-		/* For historical reasons, accept CAP_SYS_ADMIN too, with a warning */
-		if (capable(CAP_SYS_ADMIN)) {
-			printk_once(KERN_WARNING "%s (%d): "
-				 "Attempt to access syslog with CAP_SYS_ADMIN "
-				 "but no CAP_SYSLOG (deprecated).\n",
-				 current->comm, task_pid_nr(current));
-			return 0;
-		}
-		return -EPERM;
-	}
-	return 0;
-}
-
-static int syslog_print(char __user *buf, int size)
-{
-	char *text;
-	struct printk_log *msg;
-	int len = 0;
-
-	text = kmalloc(PRINTK_LOG_LINE_MAX + PRINTK_PREFIX_MAX, GFP_KERNEL);
-	if (!text)
-		return -ENOMEM;
-
-	while (size > 0) {
-		size_t n;
-		size_t skip;
-
-		raw_spin_lock_irq(&printk_logbuf_lock);
-		if (syslog_seq < printk_log_first_seq) {
-			/* messages are gone, move to first one */
-			syslog_seq = printk_log_first_seq;
-			syslog_idx = printk_log_first_idx;
-			syslog_prev = 0;
-			syslog_partial = 0;
-		}
-		if (syslog_seq == printk_log_next_seq) {
-			raw_spin_unlock_irq(&printk_logbuf_lock);
-			break;
-		}
-
-		skip = syslog_partial;
-		msg = printk_log_from_idx(syslog_idx);
-		n = printk_msg_print_text(msg, syslog_prev, true, text,
-					  PRINTK_LOG_LINE_MAX + PRINTK_PREFIX_MAX);
-		if (n - syslog_partial <= size) {
-			/* message fits into buffer, move forward */
-			syslog_idx = printk_log_next(syslog_idx);
-			syslog_seq++;
-			syslog_prev = msg->flags;
-			n -= syslog_partial;
-			syslog_partial = 0;
-		} else if (!len){
-			/* partial read(), remember position */
-			n = size;
-			syslog_partial += n;
-		} else
-			n = 0;
-		raw_spin_unlock_irq(&printk_logbuf_lock);
-
-		if (!n)
-			break;
-
-		if (copy_to_user(buf, text + skip, n)) {
-			if (!len)
-				len = -EFAULT;
-			break;
-		}
-
-		len += n;
-		size -= n;
-		buf += n;
-	}
-
-	kfree(text);
-	return len;
-}
-
-static int syslog_print_all(char __user *buf, int size, bool clear)
-{
-	char *text;
-	int len = 0;
-
-	text = kmalloc(PRINTK_LOG_LINE_MAX + PRINTK_PREFIX_MAX, GFP_KERNEL);
-	if (!text)
-		return -ENOMEM;
-
-	raw_spin_lock_irq(&printk_logbuf_lock);
-	if (buf) {
-		u64 next_seq;
-		u64 seq;
-		u32 idx;
-		enum printk_log_flags prev;
-
-		if (printk_log_clear_seq < printk_log_first_seq) {
-			/* messages are gone, move to first available one */
-			printk_log_clear_seq = printk_log_first_seq;
-			printk_log_clear_idx = printk_log_first_idx;
-		}
-
-		/*
-		 * Find first record that fits, including all following records,
-		 * into the user-provided buffer for this dump.
-		 */
-		seq = printk_log_clear_seq;
-		idx = printk_log_clear_idx;
-		prev = 0;
-		while (seq < printk_log_next_seq) {
-			struct printk_log *msg = printk_log_from_idx(idx);
-
-			len += printk_msg_print_text(msg, prev, true, NULL, 0);
-			prev = msg->flags;
-			idx = printk_log_next(idx);
-			seq++;
-		}
-
-		/* move first record forward until length fits into the buffer */
-		seq = printk_log_clear_seq;
-		idx = printk_log_clear_idx;
-		prev = 0;
-		while (len > size && seq < printk_log_next_seq) {
-			struct printk_log *msg = printk_log_from_idx(idx);
-
-			len -= printk_msg_print_text(msg, prev, true, NULL, 0);
-			prev = msg->flags;
-			idx = printk_log_next(idx);
-			seq++;
-		}
-
-		/* last message fitting into this dump */
-		next_seq = printk_log_next_seq;
-
-		len = 0;
-		prev = 0;
-		while (len >= 0 && seq < next_seq) {
-			struct printk_log *msg = printk_log_from_idx(idx);
-			int textlen;
-
-			textlen = printk_msg_print_text(msg, prev, true, text,
-							PRINTK_LOG_LINE_MAX + PRINTK_PREFIX_MAX);
-			if (textlen < 0) {
-				len = textlen;
-				break;
-			}
-			idx = printk_log_next(idx);
-			seq++;
-			prev = msg->flags;
-
-			raw_spin_unlock_irq(&printk_logbuf_lock);
-			if (copy_to_user(buf + len, text, textlen))
-				len = -EFAULT;
-			else
-				len += textlen;
-			raw_spin_lock_irq(&printk_logbuf_lock);
-
-			if (seq < printk_log_first_seq) {
-				/* messages are gone, move to next one */
-				seq = printk_log_first_seq;
-				idx = printk_log_first_idx;
-				prev = 0;
-			}
-		}
-	}
-
-	if (clear) {
-		printk_log_clear_seq = printk_log_next_seq;
-		printk_log_clear_idx = printk_log_next_idx;
-	}
-	raw_spin_unlock_irq(&printk_logbuf_lock);
-
-	kfree(text);
-	return len;
-}
-
-int do_syslog(int type, char __user *buf, int len, bool from_file)
-{
-	bool clear = false;
-	static int saved_console_loglevel = -1;
-	int error;
-
-	error = check_syslog_permissions(type, from_file);
-	if (error)
-		goto out;
-
-	error = security_syslog(type);
-	if (error)
-		return error;
-
-	switch (type) {
-	case SYSLOG_ACTION_CLOSE:	/* Close log */
-		break;
-	case SYSLOG_ACTION_OPEN:	/* Open log */
-		break;
-	case SYSLOG_ACTION_READ:	/* Read from log */
-		error = -EINVAL;
-		if (!buf || len < 0)
-			goto out;
-		error = 0;
-		if (!len)
-			goto out;
-		if (!access_ok(VERIFY_WRITE, buf, len)) {
-			error = -EFAULT;
-			goto out;
-		}
-		error = wait_event_interruptible(printk_log_wait,
-						 syslog_seq != printk_log_next_seq);
-		if (error)
-			goto out;
-		error = syslog_print(buf, len);
-		break;
-	/* Read/clear last kernel messages */
-	case SYSLOG_ACTION_READ_CLEAR:
-		clear = true;
-		/* FALL THRU */
-	/* Read last kernel messages */
-	case SYSLOG_ACTION_READ_ALL:
-		error = -EINVAL;
-		if (!buf || len < 0)
-			goto out;
-		error = 0;
-		if (!len)
-			goto out;
-		if (!access_ok(VERIFY_WRITE, buf, len)) {
-			error = -EFAULT;
-			goto out;
-		}
-		error = syslog_print_all(buf, len, clear);
-		break;
-	/* Clear ring buffer */
-	case SYSLOG_ACTION_CLEAR:
-		syslog_print_all(NULL, 0, true);
-		break;
-	/* Disable logging to console */
-	case SYSLOG_ACTION_CONSOLE_OFF:
-		if (saved_console_loglevel == -1)
-			saved_console_loglevel = console_loglevel;
-		console_loglevel = minimum_console_loglevel;
-		break;
-	/* Enable logging to console */
-	case SYSLOG_ACTION_CONSOLE_ON:
-		if (saved_console_loglevel != -1) {
-			console_loglevel = saved_console_loglevel;
-			saved_console_loglevel = -1;
-		}
-		break;
-	/* Set level of messages printed to console */
-	case SYSLOG_ACTION_CONSOLE_LEVEL:
-		error = -EINVAL;
-		if (len < 1 || len > 8)
-			goto out;
-		if (len < minimum_console_loglevel)
-			len = minimum_console_loglevel;
-		console_loglevel = len;
-		/* Implicitly re-enable logging to console */
-		saved_console_loglevel = -1;
-		error = 0;
-		break;
-	/* Number of chars in the log buffer */
-	case SYSLOG_ACTION_SIZE_UNREAD:
-		raw_spin_lock_irq(&printk_logbuf_lock);
-		if (syslog_seq < printk_log_first_seq) {
-			/* messages are gone, move to first one */
-			syslog_seq = printk_log_first_seq;
-			syslog_idx = printk_log_first_idx;
-			syslog_prev = 0;
-			syslog_partial = 0;
-		}
-		if (from_file) {
-			/*
-			 * Short-cut for poll(/"proc/kmsg") which simply checks
-			 * for pending data, not the size; return the count of
-			 * records, not the length.
-			 */
-			error = printk_log_next_idx - syslog_idx;
-		} else {
-			u64 seq = syslog_seq;
-			u32 idx = syslog_idx;
-			enum printk_log_flags prev = syslog_prev;
-
-			error = 0;
-			while (seq < printk_log_next_seq) {
-				struct printk_log *msg = printk_log_from_idx(idx);
-
-				error += printk_msg_print_text(msg, prev, true, NULL, 0);
-				idx = printk_log_next(idx);
-				seq++;
-				prev = msg->flags;
-			}
-			error -= syslog_partial;
-		}
-		raw_spin_unlock_irq(&printk_logbuf_lock);
-		break;
-	/* Size of the log buffer */
-	case SYSLOG_ACTION_SIZE_BUFFER:
-		error = printk_log_buf_len;
-		break;
-	default:
-		error = -EINVAL;
-		break;
-	}
-out:
-	return error;
-}
-
-SYSCALL_DEFINE3(syslog, int, type, char __user *, buf, int, len)
-{
-	return do_syslog(type, buf, len, SYSLOG_FROM_CALL);
-}
-
 static bool __read_mostly ignore_loglevel;
 
 static int __init ignore_loglevel_setup(char *str)
@@ -1061,11 +721,8 @@ EXPORT_SYMBOL(printk);
 
 #else /* CONFIG_PRINTK */
 
-static u64 syslog_seq;
-static u32 syslog_idx;
 static u64 console_seq;
 static u32 console_idx;
-static enum printk_log_flags syslog_prev;
 u64 printk_log_first_seq;
 u32 printk_log_first_idx;
 u64 printk_log_next_seq;
@@ -1701,9 +1358,9 @@ void register_console(struct console *newcon)
 		 * for us.
 		 */
 		raw_spin_lock_irqsave(&printk_logbuf_lock, flags);
-		console_seq = syslog_seq;
-		console_idx = syslog_idx;
-		console_prev = syslog_prev;
+		console_seq = printk_syslog_seq;
+		console_idx = printk_syslog_idx;
+		console_prev = printk_syslog_prev;
 		raw_spin_unlock_irqrestore(&printk_logbuf_lock, flags);
 		/*
 		 * We're about to replay the log buffer.  Only do this to the
diff --git a/kernel/printk/printk_syslog.c b/kernel/printk/printk_syslog.c
new file mode 100644
index 0000000..b5135b0
--- /dev/null
+++ b/kernel/printk/printk_syslog.c
@@ -0,0 +1,355 @@
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/security.h>
+#include <linux/syscalls.h>
+#include <linux/syslog.h>
+#include <linux/uaccess.h>
+
+#include "printk_log.h"
+#include "printk_syslog.h"
+
+/* the next printk record to read by syslog(READ) or /proc/kmsg */
+u64 printk_syslog_seq;
+u32 printk_syslog_idx;
+enum printk_log_flags printk_syslog_prev;
+
+#ifdef CONFIG_PRINTK
+
+static size_t printk_syslog_partial;
+
+#ifdef CONFIG_SECURITY_DMESG_RESTRICT
+int dmesg_restrict = 1;
+#else
+int dmesg_restrict;
+#endif
+
+static int printk_syslog_action_restricted(int type)
+{
+	if (dmesg_restrict)
+		return 1;
+	/* Unless restricted, we allow "read all" and "get buffer size" for everybody */
+	return type != SYSLOG_ACTION_READ_ALL && type != SYSLOG_ACTION_SIZE_BUFFER;
+}
+
+static int check_syslog_permissions(int type, bool from_file)
+{
+	/*
+	 * If this is from /proc/kmsg and we've already opened it, then we've
+	 * already done the capabilities checks at open time.
+	 */
+	if (from_file && type != SYSLOG_ACTION_OPEN)
+		return 0;
+
+	if (printk_syslog_action_restricted(type)) {
+		if (capable(CAP_SYSLOG))
+			return 0;
+		/* For historical reasons, accept CAP_SYS_ADMIN too, with a warning */
+		if (capable(CAP_SYS_ADMIN)) {
+			printk_once(KERN_WARNING "%s (%d): "
+				 "Attempt to access syslog with CAP_SYS_ADMIN "
+				 "but no CAP_SYSLOG (deprecated).\n",
+				 current->comm, task_pid_nr(current));
+			return 0;
+		}
+		return -EPERM;
+	}
+	return 0;
+}
+
+static int printk_syslog_print(char __user *buf, int size)
+{
+	char *text;
+	struct printk_log *msg;
+	int len = 0;
+
+	text = kmalloc(PRINTK_LOG_LINE_MAX + PRINTK_PREFIX_MAX, GFP_KERNEL);
+	if (!text)
+		return -ENOMEM;
+
+	while (size > 0) {
+		size_t n;
+		size_t skip;
+
+		raw_spin_lock_irq(&printk_logbuf_lock);
+		if (printk_syslog_seq < printk_log_first_seq) {
+			/* messages are gone, move to first one */
+			printk_syslog_seq = printk_log_first_seq;
+			printk_syslog_idx = printk_log_first_idx;
+			printk_syslog_prev = 0;
+			printk_syslog_partial = 0;
+		}
+		if (printk_syslog_seq == printk_log_next_seq) {
+			raw_spin_unlock_irq(&printk_logbuf_lock);
+			break;
+		}
+
+		skip = printk_syslog_partial;
+		msg = printk_log_from_idx(printk_syslog_idx);
+		n = printk_msg_print_text(msg, printk_syslog_prev, true, text,
+					  PRINTK_LOG_LINE_MAX + PRINTK_PREFIX_MAX);
+		if (n - printk_syslog_partial <= size) {
+			/* message fits into buffer, move forward */
+			printk_syslog_idx = printk_log_next(printk_syslog_idx);
+			printk_syslog_seq++;
+			printk_syslog_prev = msg->flags;
+			n -= printk_syslog_partial;
+			printk_syslog_partial = 0;
+		} else if (!len){
+			/* partial read(), remember position */
+			n = size;
+			printk_syslog_partial += n;
+		} else
+			n = 0;
+		raw_spin_unlock_irq(&printk_logbuf_lock);
+
+		if (!n)
+			break;
+
+		if (copy_to_user(buf, text + skip, n)) {
+			if (!len)
+				len = -EFAULT;
+			break;
+		}
+
+		len += n;
+		size -= n;
+		buf += n;
+	}
+
+	kfree(text);
+	return len;
+}
+
+static int printk_syslog_print_all(char __user *buf, int size, bool clear)
+{
+	char *text;
+	int len = 0;
+
+	text = kmalloc(PRINTK_LOG_LINE_MAX + PRINTK_PREFIX_MAX, GFP_KERNEL);
+	if (!text)
+		return -ENOMEM;
+
+	raw_spin_lock_irq(&printk_logbuf_lock);
+	if (buf) {
+		u64 next_seq;
+		u64 seq;
+		u32 idx;
+		enum printk_log_flags prev;
+
+		if (printk_log_clear_seq < printk_log_first_seq) {
+			/* messages are gone, move to first available one */
+			printk_log_clear_seq = printk_log_first_seq;
+			printk_log_clear_idx = printk_log_first_idx;
+		}
+
+		/*
+		 * Find first record that fits, including all following records,
+		 * into the user-provided buffer for this dump.
+		 */
+		seq = printk_log_clear_seq;
+		idx = printk_log_clear_idx;
+		prev = 0;
+		while (seq < printk_log_next_seq) {
+			struct printk_log *msg = printk_log_from_idx(idx);
+
+			len += printk_msg_print_text(msg, prev, true, NULL, 0);
+			prev = msg->flags;
+			idx = printk_log_next(idx);
+			seq++;
+		}
+
+		/* move first record forward until length fits into the buffer */
+		seq = printk_log_clear_seq;
+		idx = printk_log_clear_idx;
+		prev = 0;
+		while (len > size && seq < printk_log_next_seq) {
+			struct printk_log *msg = printk_log_from_idx(idx);
+
+			len -= printk_msg_print_text(msg, prev, true, NULL, 0);
+			prev = msg->flags;
+			idx = printk_log_next(idx);
+			seq++;
+		}
+
+		/* last message fitting into this dump */
+		next_seq = printk_log_next_seq;
+
+		len = 0;
+		prev = 0;
+		while (len >= 0 && seq < next_seq) {
+			struct printk_log *msg = printk_log_from_idx(idx);
+			int textlen;
+
+			textlen = printk_msg_print_text(msg, prev, true, text,
+							PRINTK_LOG_LINE_MAX + PRINTK_PREFIX_MAX);
+			if (textlen < 0) {
+				len = textlen;
+				break;
+			}
+			idx = printk_log_next(idx);
+			seq++;
+			prev = msg->flags;
+
+			raw_spin_unlock_irq(&printk_logbuf_lock);
+			if (copy_to_user(buf + len, text, textlen))
+				len = -EFAULT;
+			else
+				len += textlen;
+			raw_spin_lock_irq(&printk_logbuf_lock);
+
+			if (seq < printk_log_first_seq) {
+				/* messages are gone, move to next one */
+				seq = printk_log_first_seq;
+				idx = printk_log_first_idx;
+				prev = 0;
+			}
+		}
+	}
+
+	if (clear) {
+		printk_log_clear_seq = printk_log_next_seq;
+		printk_log_clear_idx = printk_log_next_idx;
+	}
+	raw_spin_unlock_irq(&printk_logbuf_lock);
+
+	kfree(text);
+	return len;
+}
+
+int do_syslog(int type, char __user *buf, int len, bool from_file)
+{
+	bool clear = false;
+	static int saved_console_loglevel = -1;
+	int error;
+
+	error = check_syslog_permissions(type, from_file);
+	if (error)
+		goto out;
+
+	error = security_syslog(type);
+	if (error)
+		return error;
+
+	switch (type) {
+	case SYSLOG_ACTION_CLOSE:	/* Close log */
+		break;
+	case SYSLOG_ACTION_OPEN:	/* Open log */
+		break;
+	case SYSLOG_ACTION_READ:	/* Read from log */
+		error = -EINVAL;
+		if (!buf || len < 0)
+			goto out;
+		error = 0;
+		if (!len)
+			goto out;
+		if (!access_ok(VERIFY_WRITE, buf, len)) {
+			error = -EFAULT;
+			goto out;
+		}
+		error = wait_event_interruptible(printk_log_wait,
+						 printk_syslog_seq != printk_log_next_seq);
+		if (error)
+			goto out;
+		error = printk_syslog_print(buf, len);
+		break;
+	/* Read/clear last kernel messages */
+	case SYSLOG_ACTION_READ_CLEAR:
+		clear = true;
+		/* FALL THRU */
+	/* Read last kernel messages */
+	case SYSLOG_ACTION_READ_ALL:
+		error = -EINVAL;
+		if (!buf || len < 0)
+			goto out;
+		error = 0;
+		if (!len)
+			goto out;
+		if (!access_ok(VERIFY_WRITE, buf, len)) {
+			error = -EFAULT;
+			goto out;
+		}
+		error = printk_syslog_print_all(buf, len, clear);
+		break;
+	/* Clear ring buffer */
+	case SYSLOG_ACTION_CLEAR:
+		printk_syslog_print_all(NULL, 0, true);
+		break;
+	/* Disable logging to console */
+	case SYSLOG_ACTION_CONSOLE_OFF:
+		if (saved_console_loglevel == -1)
+			saved_console_loglevel = console_loglevel;
+		console_loglevel = minimum_console_loglevel;
+		break;
+	/* Enable logging to console */
+	case SYSLOG_ACTION_CONSOLE_ON:
+		if (saved_console_loglevel != -1) {
+			console_loglevel = saved_console_loglevel;
+			saved_console_loglevel = -1;
+		}
+		break;
+	/* Set level of messages printed to console */
+	case SYSLOG_ACTION_CONSOLE_LEVEL:
+		error = -EINVAL;
+		if (len < 1 || len > 8)
+			goto out;
+		if (len < minimum_console_loglevel)
+			len = minimum_console_loglevel;
+		console_loglevel = len;
+		/* Implicitly re-enable logging to console */
+		saved_console_loglevel = -1;
+		error = 0;
+		break;
+	/* Number of chars in the log buffer */
+	case SYSLOG_ACTION_SIZE_UNREAD:
+		raw_spin_lock_irq(&printk_logbuf_lock);
+		if (printk_syslog_seq < printk_log_first_seq) {
+			/* messages are gone, move to first one */
+			printk_syslog_seq = printk_log_first_seq;
+			printk_syslog_idx = printk_log_first_idx;
+			printk_syslog_prev = 0;
+			printk_syslog_partial = 0;
+		}
+		if (from_file) {
+			/*
+			 * Short-cut for poll(/"proc/kmsg") which simply checks
+			 * for pending data, not the size; return the count of
+			 * records, not the length.
+			 */
+			error = printk_log_next_idx - printk_syslog_idx;
+		} else {
+			u64 seq = printk_syslog_seq;
+			u32 idx = printk_syslog_idx;
+			enum printk_log_flags prev = printk_syslog_prev;
+
+			error = 0;
+			while (seq < printk_log_next_seq) {
+				struct printk_log *msg = printk_log_from_idx(idx);
+
+				error += printk_msg_print_text(msg, prev, true, NULL, 0);
+				idx = printk_log_next(idx);
+				seq++;
+				prev = msg->flags;
+			}
+			error -= printk_syslog_partial;
+		}
+		raw_spin_unlock_irq(&printk_logbuf_lock);
+		break;
+	/* Size of the log buffer */
+	case SYSLOG_ACTION_SIZE_BUFFER:
+		error = printk_log_buf_len;
+		break;
+	default:
+		error = -EINVAL;
+		break;
+	}
+out:
+	return error;
+}
+
+SYSCALL_DEFINE3(syslog, int, type, char __user *, buf, int, len)
+{
+	return do_syslog(type, buf, len, SYSLOG_FROM_CALL);
+}
+
+#endif
diff --git a/kernel/printk/printk_syslog.h b/kernel/printk/printk_syslog.h
new file mode 100644
index 0000000..187ffdd
--- /dev/null
+++ b/kernel/printk/printk_syslog.h
@@ -0,0 +1,13 @@
+#ifndef _PRINTK_SYSLOG_H
+#define _PRINTK_SYSLOG_H
+
+#include <linux/syscalls.h>
+#include <linux/syslog.h>
+#include "printk_log.h"
+
+/* the next printk record to read by syslog(READ) or /proc/kmsg */
+extern u64 printk_syslog_seq;
+extern u32 printk_syslog_idx;
+extern enum printk_log_flags printk_syslog_prev;
+
+#endif
-- 
1.7.8.112.g3fd21

[PATCH V2 23/23] printk: Move kmsg_dump functions to separate file

[Joe Perches]

Generic restructuring.

Create kmsg_dump.c, add to Makefile and remove from printk.c

Signed-off-by: Joe Perches <joe@perches.com>
---
 kernel/printk/Makefile    |    1 +
 kernel/printk/kmsg_dump.c |  328 +++++++++++++++++++++++++++++++++++++++++++++
 kernel/printk/printk.c    |  318 -------------------------------------------
 3 files changed, 329 insertions(+), 318 deletions(-)
 create mode 100644 kernel/printk/kmsg_dump.c

diff --git a/kernel/printk/Makefile b/kernel/printk/Makefile
index 7947661..b0072b0 100644
--- a/kernel/printk/Makefile
+++ b/kernel/printk/Makefile
@@ -2,4 +2,5 @@ obj-y	= printk.o
 obj-y	+= printk_log.o
 obj-y	+= devkmsg.o
 obj-y	+= printk_syslog.o
+obj-y	+= kmsg_dump.o
 obj-$(CONFIG_A11Y_BRAILLE_CONSOLE)	+= braille.o
diff --git a/kernel/printk/kmsg_dump.c b/kernel/printk/kmsg_dump.c
new file mode 100644
index 0000000..7962172
--- /dev/null
+++ b/kernel/printk/kmsg_dump.c
@@ -0,0 +1,328 @@
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/kexec.h>
+#include <linux/moduleparam.h>
+#include <linux/export.h>
+#include <linux/kmsg_dump.h>
+#include <linux/rculist.h>
+#include <linux/stat.h>
+
+#include "printk_log.h"
+
+static DEFINE_SPINLOCK(dump_list_lock);
+static LIST_HEAD(dump_list);
+
+/**
+ * kmsg_dump_register - register a kernel log dumper.
+ * @dumper: pointer to the kmsg_dumper structure
+ *
+ * Adds a kernel log dumper to the system. The dump callback in the
+ * structure will be called when the kernel oopses or panics and must be
+ * set. Returns zero on success and %-EINVAL or %-EBUSY otherwise.
+ */
+int kmsg_dump_register(struct kmsg_dumper *dumper)
+{
+	unsigned long flags;
+	int err = -EBUSY;
+
+	/* The dump callback needs to be set */
+	if (!dumper->dump)
+		return -EINVAL;
+
+	spin_lock_irqsave(&dump_list_lock, flags);
+	/* Don't allow registering multiple times */
+	if (!dumper->registered) {
+		dumper->registered = 1;
+		list_add_tail_rcu(&dumper->list, &dump_list);
+		err = 0;
+	}
+	spin_unlock_irqrestore(&dump_list_lock, flags);
+
+	return err;
+}
+EXPORT_SYMBOL_GPL(kmsg_dump_register);
+
+/**
+ * kmsg_dump_unregister - unregister a kmsg dumper.
+ * @dumper: pointer to the kmsg_dumper structure
+ *
+ * Removes a dump device from the system. Returns zero on success and
+ * %-EINVAL otherwise.
+ */
+int kmsg_dump_unregister(struct kmsg_dumper *dumper)
+{
+	unsigned long flags;
+	int err = -EINVAL;
+
+	spin_lock_irqsave(&dump_list_lock, flags);
+	if (dumper->registered) {
+		dumper->registered = 0;
+		list_del_rcu(&dumper->list);
+		err = 0;
+	}
+	spin_unlock_irqrestore(&dump_list_lock, flags);
+	synchronize_rcu();
+
+	return err;
+}
+EXPORT_SYMBOL_GPL(kmsg_dump_unregister);
+
+static bool always_kmsg_dump;
+module_param_named(always_kmsg_dump, always_kmsg_dump, bool, S_IRUGO | S_IWUSR);
+
+/**
+ * kmsg_dump - dump kernel log to kernel message dumpers.
+ * @reason: the reason (oops, panic etc) for dumping
+ *
+ * Call each of the registered dumper's dump() callback, which can
+ * retrieve the kmsg records with kmsg_dump_get_line() or
+ * kmsg_dump_get_buffer().
+ */
+void kmsg_dump(enum kmsg_dump_reason reason)
+{
+	struct kmsg_dumper *dumper;
+	unsigned long flags;
+
+	if ((reason > KMSG_DUMP_OOPS) && !always_kmsg_dump)
+		return;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(dumper, &dump_list, list) {
+		if (dumper->max_reason && reason > dumper->max_reason)
+			continue;
+
+		/* initialize iterator with data about the stored records */
+		dumper->active = true;
+
+		raw_spin_lock_irqsave(&printk_logbuf_lock, flags);
+		dumper->cur_seq = printk_log_clear_seq;
+		dumper->cur_idx = printk_log_clear_idx;
+		dumper->next_seq = printk_log_next_seq;
+		dumper->next_idx = printk_log_next_idx;
+		raw_spin_unlock_irqrestore(&printk_logbuf_lock, flags);
+
+		/* invoke dumper which will iterate over records */
+		dumper->dump(dumper, reason);
+
+		/* reset iterator */
+		dumper->active = false;
+	}
+	rcu_read_unlock();
+}
+
+/**
+ * kmsg_dump_get_line_nolock - retrieve one kmsg log line (unlocked version)
+ * @dumper: registered kmsg dumper
+ * @syslog: include the "<4>" prefixes
+ * @line: buffer to copy the line to
+ * @size: maximum size of the buffer
+ * @len: length of line placed into buffer
+ *
+ * Start at the beginning of the kmsg buffer, with the oldest kmsg
+ * record, and copy one record into the provided buffer.
+ *
+ * Consecutive calls will return the next available record moving
+ * towards the end of the buffer with the youngest messages.
+ *
+ * A return value of FALSE indicates that there are no more records to
+ * read.
+ *
+ * The function is similar to kmsg_dump_get_line(), but grabs no locks.
+ */
+bool kmsg_dump_get_line_nolock(struct kmsg_dumper *dumper, bool syslog,
+			       char *line, size_t size, size_t *len)
+{
+	struct printk_log *msg;
+	size_t l = 0;
+	bool ret = false;
+
+	if (!dumper->active)
+		goto out;
+
+	if (dumper->cur_seq < printk_log_first_seq) {
+		/* messages are gone, move to first available one */
+		dumper->cur_seq = printk_log_first_seq;
+		dumper->cur_idx = printk_log_first_idx;
+	}
+
+	/* last entry */
+	if (dumper->cur_seq >= printk_log_next_seq)
+		goto out;
+
+	msg = printk_log_from_idx(dumper->cur_idx);
+	l = printk_msg_print_text(msg, 0, syslog, line, size);
+
+	dumper->cur_idx = printk_log_next(dumper->cur_idx);
+	dumper->cur_seq++;
+	ret = true;
+out:
+	if (len)
+		*len = l;
+	return ret;
+}
+
+/**
+ * kmsg_dump_get_line - retrieve one kmsg log line
+ * @dumper: registered kmsg dumper
+ * @syslog: include the "<4>" prefixes
+ * @line: buffer to copy the line to
+ * @size: maximum size of the buffer
+ * @len: length of line placed into buffer
+ *
+ * Start at the beginning of the kmsg buffer, with the oldest kmsg
+ * record, and copy one record into the provided buffer.
+ *
+ * Consecutive calls will return the next available record moving
+ * towards the end of the buffer with the youngest messages.
+ *
+ * A return value of FALSE indicates that there are no more records to
+ * read.
+ */
+bool kmsg_dump_get_line(struct kmsg_dumper *dumper, bool syslog,
+			char *line, size_t size, size_t *len)
+{
+	unsigned long flags;
+	bool ret;
+
+	raw_spin_lock_irqsave(&printk_logbuf_lock, flags);
+	ret = kmsg_dump_get_line_nolock(dumper, syslog, line, size, len);
+	raw_spin_unlock_irqrestore(&printk_logbuf_lock, flags);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(kmsg_dump_get_line);
+
+/**
+ * kmsg_dump_get_buffer - copy kmsg log lines
+ * @dumper: registered kmsg dumper
+ * @syslog: include the "<4>" prefixes
+ * @buf: buffer to copy the line to
+ * @size: maximum size of the buffer
+ * @len: length of line placed into buffer
+ *
+ * Start at the end of the kmsg buffer and fill the provided buffer
+ * with as many of the the *youngest* kmsg records that fit into it.
+ * If the buffer is large enough, all available kmsg records will be
+ * copied with a single call.
+ *
+ * Consecutive calls will fill the buffer with the next block of
+ * available older records, not including the earlier retrieved ones.
+ *
+ * A return value of FALSE indicates that there are no more records to
+ * read.
+ */
+bool kmsg_dump_get_buffer(struct kmsg_dumper *dumper, bool syslog,
+			  char *buf, size_t size, size_t *len)
+{
+	unsigned long flags;
+	u64 seq;
+	u32 idx;
+	u64 next_seq;
+	u32 next_idx;
+	enum printk_log_flags prev;
+	size_t l = 0;
+	bool ret = false;
+
+	if (!dumper->active)
+		goto out;
+
+	raw_spin_lock_irqsave(&printk_logbuf_lock, flags);
+	if (dumper->cur_seq < printk_log_first_seq) {
+		/* messages are gone, move to first available one */
+		dumper->cur_seq = printk_log_first_seq;
+		dumper->cur_idx = printk_log_first_idx;
+	}
+
+	/* last entry */
+	if (dumper->cur_seq >= dumper->next_seq) {
+		raw_spin_unlock_irqrestore(&printk_logbuf_lock, flags);
+		goto out;
+	}
+
+	/* calculate length of entire buffer */
+	seq = dumper->cur_seq;
+	idx = dumper->cur_idx;
+	prev = 0;
+	while (seq < dumper->next_seq) {
+		struct printk_log *msg = printk_log_from_idx(idx);
+
+		l += printk_msg_print_text(msg, prev, true, NULL, 0);
+		idx = printk_log_next(idx);
+		seq++;
+		prev = msg->flags;
+	}
+
+	/* move first record forward until length fits into the buffer */
+	seq = dumper->cur_seq;
+	idx = dumper->cur_idx;
+	prev = 0;
+	while (l > size && seq < dumper->next_seq) {
+		struct printk_log *msg = printk_log_from_idx(idx);
+
+		l -= printk_msg_print_text(msg, prev, true, NULL, 0);
+		idx = printk_log_next(idx);
+		seq++;
+		prev = msg->flags;
+	}
+
+	/* last message in next interation */
+	next_seq = seq;
+	next_idx = idx;
+
+	l = 0;
+	prev = 0;
+	while (seq < dumper->next_seq) {
+		struct printk_log *msg = printk_log_from_idx(idx);
+
+		l += printk_msg_print_text(msg, prev, syslog, buf + l, size - l);
+		idx = printk_log_next(idx);
+		seq++;
+		prev = msg->flags;
+	}
+
+	dumper->next_seq = next_seq;
+	dumper->next_idx = next_idx;
+	ret = true;
+	raw_spin_unlock_irqrestore(&printk_logbuf_lock, flags);
+out:
+	if (len)
+		*len = l;
+	return ret;
+}
+EXPORT_SYMBOL_GPL(kmsg_dump_get_buffer);
+
+/**
+ * kmsg_dump_rewind_nolock - reset the interator (unlocked version)
+ * @dumper: registered kmsg dumper
+ *
+ * Reset the dumper's iterator so that kmsg_dump_get_line() and
+ * kmsg_dump_get_buffer() can be called again and used multiple
+ * times within the same dumper.dump() callback.
+ *
+ * The function is similar to kmsg_dump_rewind(), but grabs no locks.
+ */
+void kmsg_dump_rewind_nolock(struct kmsg_dumper *dumper)
+{
+	dumper->cur_seq = printk_log_clear_seq;
+	dumper->cur_idx = printk_log_clear_idx;
+	dumper->next_seq = printk_log_next_seq;
+	dumper->next_idx = printk_log_next_idx;
+}
+
+/**
+ * kmsg_dump_rewind - reset the interator
+ * @dumper: registered kmsg dumper
+ *
+ * Reset the dumper's iterator so that kmsg_dump_get_line() and
+ * kmsg_dump_get_buffer() can be called again and used multiple
+ * times within the same dumper.dump() callback.
+ */
+void kmsg_dump_rewind(struct kmsg_dumper *dumper)
+{
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&printk_logbuf_lock, flags);
+	kmsg_dump_rewind_nolock(dumper);
+	raw_spin_unlock_irqrestore(&printk_logbuf_lock, flags);
+}
+EXPORT_SYMBOL_GPL(kmsg_dump_rewind);
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index bed0e7d..9b31ded 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -33,7 +33,6 @@
 #include <linux/kexec.h>
 #include <linux/kdb.h>
 #include <linux/ratelimit.h>
-#include <linux/kmsg_dump.h>
 #include <linux/cpu.h>
 #include <linux/notifier.h>
 #include <linux/rculist.h>
@@ -1511,321 +1510,4 @@ bool printk_timed_ratelimit(unsigned long *caller_jiffies,
 }
 EXPORT_SYMBOL(printk_timed_ratelimit);
 
-static DEFINE_SPINLOCK(dump_list_lock);
-static LIST_HEAD(dump_list);
-
-/**
- * kmsg_dump_register - register a kernel log dumper.
- * @dumper: pointer to the kmsg_dumper structure
- *
- * Adds a kernel log dumper to the system. The dump callback in the
- * structure will be called when the kernel oopses or panics and must be
- * set. Returns zero on success and %-EINVAL or %-EBUSY otherwise.
- */
-int kmsg_dump_register(struct kmsg_dumper *dumper)
-{
-	unsigned long flags;
-	int err = -EBUSY;
-
-	/* The dump callback needs to be set */
-	if (!dumper->dump)
-		return -EINVAL;
-
-	spin_lock_irqsave(&dump_list_lock, flags);
-	/* Don't allow registering multiple times */
-	if (!dumper->registered) {
-		dumper->registered = 1;
-		list_add_tail_rcu(&dumper->list, &dump_list);
-		err = 0;
-	}
-	spin_unlock_irqrestore(&dump_list_lock, flags);
-
-	return err;
-}
-EXPORT_SYMBOL_GPL(kmsg_dump_register);
-
-/**
- * kmsg_dump_unregister - unregister a kmsg dumper.
- * @dumper: pointer to the kmsg_dumper structure
- *
- * Removes a dump device from the system. Returns zero on success and
- * %-EINVAL otherwise.
- */
-int kmsg_dump_unregister(struct kmsg_dumper *dumper)
-{
-	unsigned long flags;
-	int err = -EINVAL;
-
-	spin_lock_irqsave(&dump_list_lock, flags);
-	if (dumper->registered) {
-		dumper->registered = 0;
-		list_del_rcu(&dumper->list);
-		err = 0;
-	}
-	spin_unlock_irqrestore(&dump_list_lock, flags);
-	synchronize_rcu();
-
-	return err;
-}
-EXPORT_SYMBOL_GPL(kmsg_dump_unregister);
-
-static bool always_kmsg_dump;
-module_param_named(always_kmsg_dump, always_kmsg_dump, bool, S_IRUGO | S_IWUSR);
-
-/**
- * kmsg_dump - dump kernel log to kernel message dumpers.
- * @reason: the reason (oops, panic etc) for dumping
- *
- * Call each of the registered dumper's dump() callback, which can
- * retrieve the kmsg records with kmsg_dump_get_line() or
- * kmsg_dump_get_buffer().
- */
-void kmsg_dump(enum kmsg_dump_reason reason)
-{
-	struct kmsg_dumper *dumper;
-	unsigned long flags;
-
-	if ((reason > KMSG_DUMP_OOPS) && !always_kmsg_dump)
-		return;
-
-	rcu_read_lock();
-	list_for_each_entry_rcu(dumper, &dump_list, list) {
-		if (dumper->max_reason && reason > dumper->max_reason)
-			continue;
-
-		/* initialize iterator with data about the stored records */
-		dumper->active = true;
-
-		raw_spin_lock_irqsave(&printk_logbuf_lock, flags);
-		dumper->cur_seq = printk_log_clear_seq;
-		dumper->cur_idx = printk_log_clear_idx;
-		dumper->next_seq = printk_log_next_seq;
-		dumper->next_idx = printk_log_next_idx;
-		raw_spin_unlock_irqrestore(&printk_logbuf_lock, flags);
-
-		/* invoke dumper which will iterate over records */
-		dumper->dump(dumper, reason);
-
-		/* reset iterator */
-		dumper->active = false;
-	}
-	rcu_read_unlock();
-}
-
-/**
- * kmsg_dump_get_line_nolock - retrieve one kmsg log line (unlocked version)
- * @dumper: registered kmsg dumper
- * @syslog: include the "<4>" prefixes
- * @line: buffer to copy the line to
- * @size: maximum size of the buffer
- * @len: length of line placed into buffer
- *
- * Start at the beginning of the kmsg buffer, with the oldest kmsg
- * record, and copy one record into the provided buffer.
- *
- * Consecutive calls will return the next available record moving
- * towards the end of the buffer with the youngest messages.
- *
- * A return value of FALSE indicates that there are no more records to
- * read.
- *
- * The function is similar to kmsg_dump_get_line(), but grabs no locks.
- */
-bool kmsg_dump_get_line_nolock(struct kmsg_dumper *dumper, bool syslog,
-			       char *line, size_t size, size_t *len)
-{
-	struct printk_log *msg;
-	size_t l = 0;
-	bool ret = false;
-
-	if (!dumper->active)
-		goto out;
-
-	if (dumper->cur_seq < printk_log_first_seq) {
-		/* messages are gone, move to first available one */
-		dumper->cur_seq = printk_log_first_seq;
-		dumper->cur_idx = printk_log_first_idx;
-	}
-
-	/* last entry */
-	if (dumper->cur_seq >= printk_log_next_seq)
-		goto out;
-
-	msg = printk_log_from_idx(dumper->cur_idx);
-	l = printk_msg_print_text(msg, 0, syslog, line, size);
-
-	dumper->cur_idx = printk_log_next(dumper->cur_idx);
-	dumper->cur_seq++;
-	ret = true;
-out:
-	if (len)
-		*len = l;
-	return ret;
-}
-
-/**
- * kmsg_dump_get_line - retrieve one kmsg log line
- * @dumper: registered kmsg dumper
- * @syslog: include the "<4>" prefixes
- * @line: buffer to copy the line to
- * @size: maximum size of the buffer
- * @len: length of line placed into buffer
- *
- * Start at the beginning of the kmsg buffer, with the oldest kmsg
- * record, and copy one record into the provided buffer.
- *
- * Consecutive calls will return the next available record moving
- * towards the end of the buffer with the youngest messages.
- *
- * A return value of FALSE indicates that there are no more records to
- * read.
- */
-bool kmsg_dump_get_line(struct kmsg_dumper *dumper, bool syslog,
-			char *line, size_t size, size_t *len)
-{
-	unsigned long flags;
-	bool ret;
-
-	raw_spin_lock_irqsave(&printk_logbuf_lock, flags);
-	ret = kmsg_dump_get_line_nolock(dumper, syslog, line, size, len);
-	raw_spin_unlock_irqrestore(&printk_logbuf_lock, flags);
-
-	return ret;
-}
-EXPORT_SYMBOL_GPL(kmsg_dump_get_line);
-
-/**
- * kmsg_dump_get_buffer - copy kmsg log lines
- * @dumper: registered kmsg dumper
- * @syslog: include the "<4>" prefixes
- * @buf: buffer to copy the line to
- * @size: maximum size of the buffer
- * @len: length of line placed into buffer
- *
- * Start at the end of the kmsg buffer and fill the provided buffer
- * with as many of the the *youngest* kmsg records that fit into it.
- * If the buffer is large enough, all available kmsg records will be
- * copied with a single call.
- *
- * Consecutive calls will fill the buffer with the next block of
- * available older records, not including the earlier retrieved ones.
- *
- * A return value of FALSE indicates that there are no more records to
- * read.
- */
-bool kmsg_dump_get_buffer(struct kmsg_dumper *dumper, bool syslog,
-			  char *buf, size_t size, size_t *len)
-{
-	unsigned long flags;
-	u64 seq;
-	u32 idx;
-	u64 next_seq;
-	u32 next_idx;
-	enum printk_log_flags prev;
-	size_t l = 0;
-	bool ret = false;
-
-	if (!dumper->active)
-		goto out;
-
-	raw_spin_lock_irqsave(&printk_logbuf_lock, flags);
-	if (dumper->cur_seq < printk_log_first_seq) {
-		/* messages are gone, move to first available one */
-		dumper->cur_seq = printk_log_first_seq;
-		dumper->cur_idx = printk_log_first_idx;
-	}
-
-	/* last entry */
-	if (dumper->cur_seq >= dumper->next_seq) {
-		raw_spin_unlock_irqrestore(&printk_logbuf_lock, flags);
-		goto out;
-	}
-
-	/* calculate length of entire buffer */
-	seq = dumper->cur_seq;
-	idx = dumper->cur_idx;
-	prev = 0;
-	while (seq < dumper->next_seq) {
-		struct printk_log *msg = printk_log_from_idx(idx);
-
-		l += printk_msg_print_text(msg, prev, true, NULL, 0);
-		idx = printk_log_next(idx);
-		seq++;
-		prev = msg->flags;
-	}
-
-	/* move first record forward until length fits into the buffer */
-	seq = dumper->cur_seq;
-	idx = dumper->cur_idx;
-	prev = 0;
-	while (l > size && seq < dumper->next_seq) {
-		struct printk_log *msg = printk_log_from_idx(idx);
-
-		l -= printk_msg_print_text(msg, prev, true, NULL, 0);
-		idx = printk_log_next(idx);
-		seq++;
-		prev = msg->flags;
-	}
-
-	/* last message in next interation */
-	next_seq = seq;
-	next_idx = idx;
-
-	l = 0;
-	prev = 0;
-	while (seq < dumper->next_seq) {
-		struct printk_log *msg = printk_log_from_idx(idx);
-
-		l += printk_msg_print_text(msg, prev, syslog, buf + l, size - l);
-		idx = printk_log_next(idx);
-		seq++;
-		prev = msg->flags;
-	}
-
-	dumper->next_seq = next_seq;
-	dumper->next_idx = next_idx;
-	ret = true;
-	raw_spin_unlock_irqrestore(&printk_logbuf_lock, flags);
-out:
-	if (len)
-		*len = l;
-	return ret;
-}
-EXPORT_SYMBOL_GPL(kmsg_dump_get_buffer);
-
-/**
- * kmsg_dump_rewind_nolock - reset the interator (unlocked version)
- * @dumper: registered kmsg dumper
- *
- * Reset the dumper's iterator so that kmsg_dump_get_line() and
- * kmsg_dump_get_buffer() can be called again and used multiple
- * times within the same dumper.dump() callback.
- *
- * The function is similar to kmsg_dump_rewind(), but grabs no locks.
- */
-void kmsg_dump_rewind_nolock(struct kmsg_dumper *dumper)
-{
-	dumper->cur_seq = printk_log_clear_seq;
-	dumper->cur_idx = printk_log_clear_idx;
-	dumper->next_seq = printk_log_next_seq;
-	dumper->next_idx = printk_log_next_idx;
-}
-
-/**
- * kmsg_dump_rewind - reset the interator
- * @dumper: registered kmsg dumper
- *
- * Reset the dumper's iterator so that kmsg_dump_get_line() and
- * kmsg_dump_get_buffer() can be called again and used multiple
- * times within the same dumper.dump() callback.
- */
-void kmsg_dump_rewind(struct kmsg_dumper *dumper)
-{
-	unsigned long flags;
-
-	raw_spin_lock_irqsave(&printk_logbuf_lock, flags);
-	kmsg_dump_rewind_nolock(dumper);
-	raw_spin_unlock_irqrestore(&printk_logbuf_lock, flags);
-}
-EXPORT_SYMBOL_GPL(kmsg_dump_rewind);
 #endif
-- 
1.7.8.112.g3fd21

Re: [PATCH V2 00/23] printk: refactoring

[Joe Perches]

On Fri, 2012-11-02 at 06:49 -0700, Joe Perches wrote:
> On Wed, 2012-10-24 at 20:43 -0700, Joe Perches wrote:
> > Make printk a bit more readable.
> 
> Andrew?  Are you going to apply this again for -next?

Andrew?  Any answer?

> > Created directory:
> > 	kernel/printk
> > Created source files:
> > 	printk.c		Generic printk and console routines
> > 	printk_log.[ch]		Log buffer routines
> > 	printk_syslog.[ch]	syslog(2) routines
> > 	braille.c		Braille console support
> > 	devkmsg.c		/dev/kmsg support
> > 	kmsg_dump.c		kmsg_dump support
> > 
> > Changes from v1:
> > Fix braille.h: _braille_console_setup return value
> > Remove duplicated #define
> > Add missing #include <linux/uaccess.h>
> 

Re: [PATCH V2 00/23] printk: refactoring

[Andrew Morton]

On Mon, 12 Nov 2012 14:54:10 -0800
Joe Perches <joe@perches.com> wrote:

> On Fri, 2012-11-02 at 06:49 -0700, Joe Perches wrote:
> > On Wed, 2012-10-24 at 20:43 -0700, Joe Perches wrote:
> > > Make printk a bit more readable.
> > 
> > Andrew?  Are you going to apply this again for -next?
> 
> Andrew?  Any answer?

Backlogged, not lost.  Hopefully this week or next week.

I trust it has had more thorough compilation coverage testing
than v1?

Re: [PATCH V2 00/23] printk: refactoring

[Joe Perches]

On Mon, 2012-11-12 at 15:26 -0800, Andrew Morton wrote:
> On Mon, 12 Nov 2012 14:54:10 -0800
> Joe Perches <joe@perches.com> wrote:
> 
> > On Fri, 2012-11-02 at 06:49 -0700, Joe Perches wrote:
> > > On Wed, 2012-10-24 at 20:43 -0700, Joe Perches wrote:
> > > > Make printk a bit more readable.
> > > 
> > > Andrew?  Are you going to apply this again for -next?
> > 
> > Andrew?  Any answer?
> 
> Backlogged, not lost.  Hopefully this week or next week.

Thanks.

> I trust it has had more thorough compilation coverage testing
> than v1?

Just a bit.  It does incorporate fixes to all known defects though.

Re: [PATCH V2 00/23] printk: refactoring

[Joe Perches]

On Mon, 2012-11-12 at 15:26 -0800, Andrew Morton wrote:
> On Mon, 12 Nov 2012 14:54:10 -0800
> Joe Perches <joe@perches.com> wrote:
> 
> > On Fri, 2012-11-02 at 06:49 -0700, Joe Perches wrote:
> > > On Wed, 2012-10-24 at 20:43 -0700, Joe Perches wrote:
> > > > Make printk a bit more readable.
> > > 
> > > Andrew?  Are you going to apply this again for -next?
> > 
> > Andrew?  Any answer?
> 
> Backlogged, not lost.  Hopefully this week or next week.
> 
> I trust it has had more thorough compilation coverage testing
> than v1?

Well, it's getting to be too late for this series.

There are a few outstanding patches to printk that
should be queued before this restructuring is redone
for the next cycle.

Kay has some, Jan has some.

Likely those should go first.

When would be the best time to resubmit and get this
into -next?

Re: [PATCH V2 00/23] printk: refactoring

[Andrew Morton]

On Thu, 29 Nov 2012 14:08:15 -0800
Joe Perches <joe@perches.com> wrote:

> On Mon, 2012-11-12 at 15:26 -0800, Andrew Morton wrote:
> > On Mon, 12 Nov 2012 14:54:10 -0800
> > Joe Perches <joe@perches.com> wrote:
> > 
> > > On Fri, 2012-11-02 at 06:49 -0700, Joe Perches wrote:
> > > > On Wed, 2012-10-24 at 20:43 -0700, Joe Perches wrote:
> > > > > Make printk a bit more readable.
> > > > 
> > > > Andrew?  Are you going to apply this again for -next?
> > > 
> > > Andrew?  Any answer?
> > 
> > Backlogged, not lost.  Hopefully this week or next week.
> > 
> > I trust it has had more thorough compilation coverage testing
> > than v1?
> 
> Well, it's getting to be too late for this series.

Yeah sorry, stuff got in the way, then people patched printk.c.

> When would be the best time to resubmit and get this
> into -next?

I think at rc1.  Then if all is OK I'd aim at a merge for rc2 or rc3
because these patches are rather a pain to keep alive.

Re: [PATCH V2 00/23] printk: refactoring

[Joe Perches]

On Thu, 2012-11-29 at 14:21 -0800, Andrew Morton wrote:
> On Thu, 29 Nov 2012 14:08:15 -0800
> Joe Perches <joe@perches.com> wrote:
> > Well, it's getting to be too late for this series.
> 
> Yeah sorry, stuff got in the way, then people patched printk.c.

No worries.

> > When would be the best time to resubmit and get this
> > into -next?
> 
> I think at rc1.  Then if all is OK I'd aim at a merge for rc2 or rc3
> because these patches are rather a pain to keep alive.

It's still a scheduling issue with Kay and Jan's patches.
Does anyone have any idea if/when those patches are going in?

Re: [PATCH V2 00/23] printk: refactoring

[Kay Sievers]

On Thu, Nov 29, 2012 at 11:46 PM, Joe Perches <joe@perches.com> wrote:

> It's still a scheduling issue with Kay and Jan's patches.
> Does anyone have any idea if/when those patches are going in?

I was expecting that Jan rebases the patches incorporating
the latest fix. Jan?

It should not hold back anything else that is already ready to merge.
We will manage it to rebase, I think.

Thanks,
Kay

Re: [PATCH V2 00/23] printk: refactoring

["Jan H. Schönherr"]

Am 29.11.2012 23:53, schrieb Kay Sievers:
> On Thu, Nov 29, 2012 at 11:46 PM, Joe Perches <joe@perches.com> wrote:
> 
>> It's still a scheduling issue with Kay and Jan's patches.
>> Does anyone have any idea if/when those patches are going in?
> 
> I was expecting that Jan rebases the patches incorporating
> the latest fix. Jan?

This weekend, hopefully, I have time to finish this.

I found one or two other bugs in my code in the meantime, so the
delay has also some positive effects. :)

Regards
Jan