[PATCH 15/23] printk: Add and use printk_log.h
From: Joe Perches
Date: Wed Oct 17 2012 - 02:08:55 EST
Create a header file for printk_log functions and variables.
Signed-off-by: Joe Perches <joe@xxxxxxxxxxx>
---
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
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