Add a struct syslog_namespace which contains the necessary
members for hanlding syslog and realize get_syslog_ns and
put_syslog_ns API.
Signed-off-by: Rui Xiang <rui.xi...@huawei.com>
---
include/linux/syslog.h | 68 ++++++++++++++++++++++++++++++++++++++++++++++++++
kernel/printk.c | 7 ------
2 files changed, 68 insertions(+), 7 deletions(-)
diff --git a/include/linux/syslog.h b/include/linux/syslog.h
index 98a3153..425fafe 100644
--- a/include/linux/syslog.h
+++ b/include/linux/syslog.h
@@ -21,6 +21,9 @@
#ifndef _LINUX_SYSLOG_H
#define _LINUX_SYSLOG_H
+#include <linux/slab.h>
+#include <linux/kref.h>
+
/* Close the log. Currently a NOP. */
#define SYSLOG_ACTION_CLOSE 0
/* Open the log. Currently a NOP. */
@@ -47,6 +50,71 @@
#define SYSLOG_FROM_READER 0
#define SYSLOG_FROM_PROC 1
+enum 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 syslog_namespace {
+ struct kref kref; /* syslog_ns reference count & control */
+
+ raw_spinlock_t logbuf_lock; /* access conflict locker */
+ /* cpu currently holding logbuf_lock of ns */
+ unsigned int logbuf_cpu;
+
+ /* index and sequence number of the first record stored in the buffer */
+ u64 log_first_seq;
+ u32 log_first_idx;
+
+ /* index and sequence number of the next record stored in the buffer */
+ u64 log_next_seq;
+ u32 log_next_idx;
+
+ /* the next printk record to read after the last 'clear' command */
+ u64 clear_seq;
+ u32 clear_idx;
+
+ char *log_buf;
+ u32 log_buf_len;
+
+ /* the next printk record to write to the console */
+ u64 console_seq;
+ u32 console_idx;
+
+ /* the next printk record to read by syslog(READ) or /proc/kmsg */
+ u64 syslog_seq;
+ u32 syslog_idx;
+ enum log_flags syslog_prev;
+ size_t syslog_partial;
+
+ int dmesg_restrict;
+};
+
+static inline struct syslog_namespace *get_syslog_ns(
+ struct syslog_namespace *ns)
+{
+ if (ns)
+ kref_get(&ns->kref);
+ return ns;
+}
+
+static inline void free_syslog_ns(struct kref *kref)
+{
+ struct syslog_namespace *ns;
+ ns = container_of(kref, struct syslog_namespace, kref);
+
+ kfree(ns->log_buf);
+ kfree(ns);
+}
+
+static inline void put_syslog_ns(struct syslog_namespace *ns)
+{
+ if (ns)
+ kref_put(&ns->kref, free_syslog_ns);
+}
+
int do_syslog(int type, char __user *buf, int count, bool from_file);
#endif /* _LINUX_SYSLOG_H */
diff --git a/kernel/printk.c b/kernel/printk.c
index 69b0890..665cfdc 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -193,13 +193,6 @@ static int console_may_schedule;
* separated by ',', and find the message after the ';' character.
*/
-enum 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 log {
u64 ts_nsec; /* timestamp in nanoseconds */
u16 len; /* length of entire record */
--
1.8.2.2
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