[PATCH 00/23] printk: refactoring

[PATCH 00/23] printk: refactoring

[Joe Perches]

Make printk a bit more readable.

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                          | 1515 ++++++++++++
 kernel/printk/printk_log.c                      |  263 +++
 kernel/printk/printk_log.h                      |  123 +
 kernel/printk/printk_syslog.c                   |  354 +++
 kernel/printk/printk_syslog.h                   |   12 +
 15 files changed, 3031 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

-- 
1.7.10.4

[PATCH 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
-- 
1.7.10.4

[PATCH 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;
-- 
1.7.10.4

[PATCH 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.

cc: Samuel Thibault <samuel.thibault@ens-lyon.org>
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..d2e6bc3
--- /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 *str;
+}
+
+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;
-- 
1.7.10.4

[PATCH 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 file 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;
-- 
1.7.10.4

[PATCH 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 file 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);
-- 
1.7.10.4

[PATCH 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 file 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)
-- 
1.7.10.4

[PATCH 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 file 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;
 }
 
 /**
-- 
1.7.10.4

[PATCH 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 file 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;
 	}
-- 
1.7.10.4

[PATCH 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 file 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;
 
-- 
1.7.10.4

[PATCH 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);
 }
 
-- 
1.7.10.4

[PATCH 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 file 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
-- 
1.7.10.4

[PATCH 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 file 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;
 }
-- 
1.7.10.4

[PATCH 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 file 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,
-- 
1.7.10.4

[PATCH 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 file 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) {
-- 
1.7.10.4

[PATCH 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
-- 
1.7.10.4

[PATCH 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 */
-- 
1.7.10.4

[PATCH 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 file changed, 1 insertion(+)

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;
-- 
1.7.10.4

[PATCH 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.

Signed-off-by: Joe Perches <joe@perches.com>
---
 kernel/printk/printk.c     |   24 ++++++++++--------------
 kernel/printk/printk_log.h |    3 +++
 2 files changed, 13 insertions(+), 14 deletions(-)

diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 3b5c10e..43550a5 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 +1462,8 @@ EXPORT_SYMBOL(printk);
 
 #else /* CONFIG_PRINTK */
 
-#define LOG_LINE_MAX		0
-#define PREFIX_MAX		0
-#define LOG_LINE_MAX 0
+#define PRINTK_LOG_LINE_MAX	0
+#define PRINTK_PREFIX_MAX		0
 static u64 syslog_seq;
 static u32 syslog_idx;
 static u64 console_seq;
@@ -1793,7 +1789,7 @@ 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..a7125d5 100644
--- a/kernel/printk/printk_log.h
+++ b/kernel/printk/printk_log.h
@@ -92,6 +92,9 @@ struct printk_log {
 #endif
 #define __PRINTK_LOG_BUF_LEN (1 << CONFIG_LOG_BUF_SHIFT)
 
+#define PRINTK_PREFIX_MAX	32
+#define PRINTK_LOG_LINE_MAX	(1024 - PRINTK_PREFIX_MAX)
+
 extern raw_spinlock_t printk_logbuf_lock;
 extern wait_queue_head_t printk_log_wait;
 extern u64 printk_log_first_seq;
-- 
1.7.10.4

[PATCH 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 43550a5..875e0dc 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
-- 
1.7.10.4

[PATCH 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 875e0dc..cd0d317 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;
 	}
 
@@ -1186,9 +1186,14 @@ 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 */
@@ -1549,8 +1554,8 @@ 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;
@@ -2104,7 +2109,7 @@ 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++;
@@ -2200,7 +2205,7 @@ 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;
@@ -2213,7 +2218,7 @@ 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;
@@ -2228,7 +2233,7 @@ 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 a7125d5..6075297 100644
--- a/kernel/printk/printk_log.h
+++ b/kernel/printk/printk_log.h
@@ -115,5 +115,9 @@ 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
-- 
1.7.10.4

[PATCH 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 cd0d317..343b0ce 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;
@@ -1186,13 +1081,6 @@ 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 */
-- 
1.7.10.4

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

[Joe Perches]

Move syslog functions to a separate file.
Add compilation unit to Makefile.

Signed-off-by: Joe Perches <joe@perches.com>
---
 kernel/printk/Makefile        |    1 +
 kernel/printk/printk.c        |  351 +---------------------------------------
 kernel/printk/printk_syslog.c |  354 +++++++++++++++++++++++++++++++++++++++++
 kernel/printk/printk_syslog.h |   12 ++
 4 files changed, 371 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 343b0ce..cba438e 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)
@@ -1063,11 +723,8 @@ EXPORT_SYMBOL(printk);
 
 #define PRINTK_LOG_LINE_MAX	0
 #define PRINTK_PREFIX_MAX		0
-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;
@@ -1703,9 +1360,9 @@ 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..65f288b
--- /dev/null
+++ b/kernel/printk/printk_syslog.c
@@ -0,0 +1,354 @@
+#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 "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..dce93c0
--- /dev/null
+++ b/kernel/printk/printk_syslog.h
@@ -0,0 +1,12 @@
+#ifndef _PRINTK_SYSLOG_H
+#define _PRINTK_SYSLOG_H
+
+#include <linux/syscalls.h>
+#include <linux/syslog.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
-- 
1.7.10.4

[PATCH 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 cba438e..b4187f3 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>
@@ -1513,321 +1512,4 @@ 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
-- 
1.7.10.4

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

[Samuel Thibault]

Joe Perches, le Tue 16 Oct 2012 23:06:07 -0700, a écrit :
> Create files with prototypes and static inlines for braille
> support.  Make braille_console functions return 1 on success.
> 
> cc: Samuel Thibault <samuel.thibault@ens-lyon.org>
> Signed-off-by: Joe Perches <joe@perches.com>

Acked-by: Samuel Thibault <samuel.thibault@ens-lyon.org>

> ---
>  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..d2e6bc3
> --- /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 *str;
> +}
> +
> +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;
> -- 
> 1.7.10.4
> 

-- 
Samuel
J'ai beaucoup de mal a lire fcola quand il y a toutes les annonces de howto :
les annonces interessantes sont noyees dans les howto. Ca serait pas mal
de degager toute cette pollution dans un autre groupe.
  JLM in Guide du linuxien pervers : "Cachez ces doc que je ne saurais voir"

Re: [PATCH 00/23] printk: refactoring

[Andrew Morton]

On Tue, 16 Oct 2012 23:06:04 -0700
Joe Perches <joe@perches.com> wrote:

> Make printk a bit more readable.
> 
> 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

OK, nobody's allowed to change the printk code for two months.

>  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                          | 1515 ++++++++++++
>  kernel/printk/printk_log.c                      |  263 +++
>  kernel/printk/printk_log.h                      |  123 +
>  kernel/printk/printk_syslog.c                   |  354 +++
>  kernel/printk/printk_syslog.h                   |   12 +

It wouldn't hurt to describe the design here a bit.  How was the code
partitioned and what is the role of each file?

That's reasonably obvious from the names, but some might wonder about
the difference between printk_log and printk_syslog and how that
division was decided upon.

Re: [PATCH 00/23] printk: refactoring

[Joe Perches]

On Thu, 2012-10-18 at 16:16 -0700, Andrew Morton wrote:
> On Tue, 16 Oct 2012 23:06:04 -0700
> Joe Perches <joe@perches.com> wrote:
> 
> > Make printk a bit more readable.
[]
> OK, nobody's allowed to change the printk code for two months.

[filelist]

> It wouldn't hurt to describe the design here a bit.  How was the code
> partitioned and what is the role of each file?

Design?  Have you looked at printk recently?

I think you called it something like "eye gouging"
or maybe "burn it down".

Dunno how anyone could consider what there anything
other than accreted.

I just tried to break it up into somewhat sensible blocks.

> That's reasonably obvious from the names, but some might wonder about
> the difference between printk_log and printk_syslog and how that
> division was decided upon.

None of the filenames are great.

I still want to break out the console code from what's
left of printk.c eventually.

I think what would help most is a Documentation/printk.txt
file explaining how it all works.

cheers, Joe

Re: [PATCH 00/23] printk: refactoring

[Joe Perches]

On Thu, 2012-10-18 at 16:16 -0700, Andrew Morton wrote:
> It wouldn't hurt to describe the design here a bit.  How was the code
> partitioned and what is the role of each file?
> 
> That's reasonably obvious from the names, but some might wonder about
> the difference between printk_log and printk_syslog and how that
> division was decided upon.

printk_log is Kay's record oriented logging stuff,
printk_syslog is syslog(2),
the rest is I hope trivially obvious.

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

[Stephen Warren]

On 10/17/2012 12:06 AM, Joe Perches wrote:
> Create files with prototypes and static inlines for braille
> support.  Make braille_console functions return 1 on success.

Joe,

Between next-20121022 and next-20121023, the serial console (on the ARM
SoC Tegra at least) stopped working. The issue bisects down to this
commit. I haven't had a chance to investigate why yet, I just finished
bisected.

earlyprintk over the same UART works. Once the system has booted, a few
late kernel messages do appear, and then getty/login over the UART
works. So, it's just the printk messages that disappeared.

In case it's relevant, my command-line is:

console=ttyS0,115200n8 loglevel=8 rootwait rw earlyprintk
root=PARTUUID=b2f82cda-2535-4779-b467-094a210fbae7

I'll continue to investigate further tomorrow, but just wanted to give
you a heads-up in case you could immediately see anything obvious in the
code.

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

[Joe Perches]

On Wed, 2012-10-24 at 18:12 -0600, Stephen Warren wrote:
> On 10/17/2012 12:06 AM, Joe Perches wrote:
> > Create files with prototypes and static inlines for braille
> > support.  Make braille_console functions return 1 on success.
> 
> Joe,
> 
> Between next-20121022 and next-20121023, the serial console (on the ARM
> SoC Tegra at least) stopped working. The issue bisects down to this
> commit. I haven't had a chance to investigate why yet, I just finished
> bisected.
> 
> earlyprintk over the same UART works. Once the system has booted, a few
> late kernel messages do appear, and then getty/login over the UART
> works. So, it's just the printk messages that disappeared.
> 
> In case it's relevant, my command-line is:
> 
> console=ttyS0,115200n8 loglevel=8 rootwait rw earlyprintk
> root=PARTUUID=b2f82cda-2535-4779-b467-094a210fbae7
> 
> I'll continue to investigate further tomorrow, but just wanted to give
> you a heads-up in case you could immediately see anything obvious in the
> code.

Hi Stephen.

Thanks, I appreciate the heads-up.  This should be solved
by Ming Lei's patch (which I've incorporated into a V2
series I will post shortly).

https://lkml.org/lkml/2012/10/23/307

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

[Stephen Warren]

On 10/24/2012 06:31 PM, Joe Perches wrote:
> On Wed, 2012-10-24 at 18:12 -0600, Stephen Warren wrote:
>> On 10/17/2012 12:06 AM, Joe Perches wrote:
>>> Create files with prototypes and static inlines for braille
>>> support.  Make braille_console functions return 1 on success.
>>
>> Joe,
>>
>> Between next-20121022 and next-20121023, the serial console (on the ARM
>> SoC Tegra at least) stopped working. The issue bisects down to this
>> commit. I haven't had a chance to investigate why yet, I just finished
>> bisected.
>>
>> earlyprintk over the same UART works. Once the system has booted, a few
>> late kernel messages do appear, and then getty/login over the UART
>> works. So, it's just the printk messages that disappeared.
>>
>> In case it's relevant, my command-line is:
>>
>> console=ttyS0,115200n8 loglevel=8 rootwait rw earlyprintk
>> root=PARTUUID=b2f82cda-2535-4779-b467-094a210fbae7
>>
>> I'll continue to investigate further tomorrow, but just wanted to give
>> you a heads-up in case you could immediately see anything obvious in the
>> code.
> 
> Hi Stephen.
> 
> Thanks, I appreciate the heads-up.  This should be solved
> by Ming Lei's patch (which I've incorporated into a V2
> series I will post shortly).
> 
> https://lkml.org/lkml/2012/10/23/307

Thanks. I can confirmed that patch does fix my issue.