Re: [RFC v3 1/9] printk: extract kmsg-related routines from printk.c to kmsg.c

From: kbuild test robot
Date: Mon Oct 19 2015 - 09:54:21 EST

Hi Paul,

[auto build test ERROR on next-20151016 -- if it's inappropriate base, please suggest rules for selecting the more suitable base]

url: https://github.com/0day-ci/linux/commits/Paul-Osmialowski/Additional-kmsg-devices/20151019-211509
config: x86_64-allnoconfig (attached as .config)
reproduce:
# save the attached .config to linux build tree
make ARCH=x86_64

All error/warnings (new ones prefixed by >>):

In file included from kernel/printk/printk.c:50:0:
>> kernel/printk/printk.h:195:1: error: expected identifier or '(' before '{' token
{
^
>> kernel/printk/printk.c:1541:0: warning: "LOG_LINE_MAX" redefined
#define LOG_LINE_MAX 0
^
In file included from kernel/printk/printk.c:50:0:
kernel/printk/printk.h:10:0: note: this is the location of the previous definition
#define LOG_LINE_MAX (1024 - PREFIX_MAX)
^
>> kernel/printk/printk.c:1542:0: warning: "PREFIX_MAX" redefined
#define PREFIX_MAX 0
^
In file included from kernel/printk/printk.c:50:0:
kernel/printk/printk.h:9:0: note: this is the location of the previous definition
#define PREFIX_MAX 32
^
>> kernel/printk/printk.h:192:22: warning: 'msg_print_text' used but never defined
static inline size_t msg_print_text(const struct printk_log *msg,
^

vim +195 kernel/printk/printk.h

3
4 #include <linux/printk.h>
5 #include <linux/spinlock_types.h>
6 #include <linux/types.h>
7 #include <linux/wait.h>
8
> 9 #define PREFIX_MAX 32
10 #define LOG_LINE_MAX (1024 - PREFIX_MAX)
11
12 /*
13 * The printk log buffer consists of a chain of concatenated variable
14 * length records. Every record starts with a record header, containing
15 * the overall length of the record.
16 *
17 * The heads to the first and last entry in the buffer, as well as the
18 * sequence numbers of these entries are maintained when messages are
19 * stored.
20 *
21 * If the heads indicate available messages, the length in the header
22 * tells the start next message. A length == 0 for the next message
23 * indicates a wrap-around to the beginning of the buffer.
24 *
25 * Every record carries the monotonic timestamp in microseconds, as well as
26 * the standard userspace syslog level and syslog facility. The usual
27 * kernel messages use LOG_KERN; userspace-injected messages always carry
28 * a matching syslog facility, by default LOG_USER. The origin of every
29 * message can be reliably determined that way.
30 *
31 * The human readable log message directly follows the message header. The
32 * length of the message text is stored in the header, the stored message
33 * is not terminated.
34 *
35 * Optionally, a message can carry a dictionary of properties (key/value pairs),
36 * to provide userspace with a machine-readable message context.
37 *
38 * Examples for well-defined, commonly used property names are:
39 * DEVICE=b12:8 device identifier
40 * b12:8 block dev_t
41 * c127:3 char dev_t
42 * n8 netdev ifindex
43 * +sound:card0 subsystem:devname
44 * SUBSYSTEM=pci driver-core subsystem name
45 *
46 * Valid characters in property names are [a-zA-Z0-9.-_]. The plain text value
47 * follows directly after a '=' character. Every property is terminated by
48 * a '\0' character. The last property is not terminated.
49 *
50 * Example of a message structure:
51 * 0000 ff 8f 00 00 00 00 00 00 monotonic time in nsec
52 * 0008 34 00 record is 52 bytes long
53 * 000a 0b 00 text is 11 bytes long
54 * 000c 1f 00 dictionary is 23 bytes long
55 * 000e 03 00 LOG_KERN (facility) LOG_ERR (level)
56 * 0010 69 74 27 73 20 61 20 6c "it's a l"
57 * 69 6e 65 "ine"
58 * 001b 44 45 56 49 43 "DEVIC"
59 * 45 3d 62 38 3a 32 00 44 "E=b8:2\0D"
60 * 52 49 56 45 52 3d 62 75 "RIVER=bu"
61 * 67 "g"
62 * 0032 00 00 00 padding to next message header
63 *
64 * The 'struct printk_log' buffer header must never be directly exported to
65 * userspace, it is a kernel-private implementation detail that might
66 * need to be changed in the future, when the requirements change.
67 *
68 * /dev/kmsg exports the structured data in the following line format:
69 * "<level>,<sequnum>,<tstamp>,<contflag>[,additional_vals, ... ];<msg txt>\n"
70 *
71 * Users of the export format should ignore possible additional values
72 * separated by ',', and find the message after the ';' character.
73 *
74 * The optional key/value pairs are attached as continuation lines starting
75 * with a space character and terminated by a newline. All possible
76 * non-prinatable characters are escaped in the "\xff" notation.
77 */
78
79 enum log_flags {
80 LOG_NOCONS = 1, /* already flushed, do not print to console */
81 LOG_NEWLINE = 2, /* text ended with a newline */
82 LOG_PREFIX = 4, /* text started with a prefix */
83 LOG_CONT = 8, /* text is a fragment of a continuation line */
84 };
85
86 struct printk_log {
87 u64 ts_nsec; /* timestamp in nanoseconds */
88 u16 len; /* length of entire record */
89 u16 text_len; /* length of text buffer */
90 u16 dict_len; /* length of dictionary buffer */
91 u8 facility; /* syslog facility */
92 u8 flags:5; /* internal record flags */
93 u8 level:3; /* syslog level */
94 };
95
96 /*
97 * The logbuf_lock protects kmsg buffer, indices, counters. This can be taken
98 * within the scheduler's rq lock. It must be released before calling
99 * console_unlock() or anything else that might wake up a process.
100 */
101 extern raw_spinlock_t logbuf_lock;
102
103 #ifdef CONFIG_PRINTK
104
105 extern wait_queue_head_t log_wait;
106
107 /* index and sequence number of the first record stored in the buffer */
108 extern u64 log_first_seq;
109 extern u32 log_first_idx;
110
111 /* index and sequence number of the next record to store in the buffer */
112 extern u64 log_next_seq;
113 extern u32 log_next_idx;
114
115 /* the next printk record to read after the last 'clear' command */
116 extern u64 clear_seq;
117 extern u32 clear_idx;
118
119 ssize_t msg_print_ext_header(char *buf, size_t size,
120 struct printk_log *msg, u64 seq,
121 enum log_flags prev_flags);
122
123 ssize_t msg_print_ext_body(char *buf, size_t size,
124 char *dict, size_t dict_len,
125 char *text, size_t text_len);
126
127 size_t msg_print_text(const struct printk_log *msg, enum log_flags prev,
128 bool syslog, char *buf, size_t size);
129
130 /* get next record; idx must point to valid msg */
131 static inline u32 log_next(u32 idx)
132 {
133 char *log_buf = log_buf_addr_get();
134 struct printk_log *msg = (struct printk_log *)(log_buf + idx);
135
136 /* length == 0 indicates the end of the buffer; wrap */
137 /*
138 * A length == 0 record is the end of buffer marker. Wrap around and
139 * read the message at the start of the buffer as *this* one, and
140 * return the one after that.
141 */
142 if (!msg->len) {
143 msg = (struct printk_log *)log_buf;
144 return msg->len;
145 }
146 return idx + msg->len;
147 }
148
149 /* get record by index; idx must point to valid msg */
150 static inline struct printk_log *log_from_idx(u32 idx)
151 {
152 char *log_buf = log_buf_addr_get();
153 struct printk_log *msg = (struct printk_log *)(log_buf + idx);
154
155 /*
156 * A length == 0 record is the end of buffer marker. Wrap around and
157 * read the message at the start of the buffer.
158 */
159 if (!msg->len)
160 return (struct printk_log *)log_buf;
161 return msg;
162 }
163
164 /* human readable text of the record */
165 static inline char *log_text(const struct printk_log *msg)
166 {
167 return (char *)msg + sizeof(struct printk_log);
168 }
169
170 /* optional key/value pair dictionary attached to the record */
171 static inline char *log_dict(const struct printk_log *msg)
172 {
173 return (char *)msg + sizeof(struct printk_log) + msg->text_len;
174 }
175
176 #else
177
178 static inline ssize_t msg_print_ext_header(char *buf, size_t size,
179 struct printk_log *msg, u64 seq,
180 enum log_flags prev_flags)
181 {
182 return 0;
183 }
184
185 static inline ssize_t msg_print_ext_body(char *buf, size_t size,
186 char *dict, size_t dict_len,
187 char *text, size_t text_len)
188 {
189 return 0;
190 }
191
> 192 static inline size_t msg_print_text(const struct printk_log *msg,
193 enum log_flags prev, bool syslog, char *buf,
194 size_t size);
> 195 {
196 return 0;
197 }
198

---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation

Attachment: .config.gz
Description: Binary data