1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
|
From 171ee108014d67150846f1b8f978921cefc7b1e3 Mon Sep 17 00:00:00 2001
From: John Ogness <john.ogness@linutronix.de>
Date: Mon, 21 Dec 2020 10:27:58 +0106
Subject: [PATCH 093/323] printk: kmsg_dump: remove _nolock() variants
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/5.10/older/patches-5.10.204-rt100.tar.xz
kmsg_dump_rewind() and kmsg_dump_get_line() are lockless, so there is
no need for _nolock() variants. Remove these functions and switch all
callers of the _nolock() variants.
The functions without _nolock() were chosen because they are already
exported to kernel modules.
Signed-off-by: John Ogness <john.ogness@linutronix.de>
---
arch/powerpc/xmon/xmon.c | 4 +--
include/linux/kmsg_dump.h | 18 +----------
kernel/debug/kdb/kdb_main.c | 8 ++---
kernel/printk/printk.c | 60 +++++--------------------------------
4 files changed, 15 insertions(+), 75 deletions(-)
diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
index 9f62cca6c594..2eef587bf51d 100644
--- a/arch/powerpc/xmon/xmon.c
+++ b/arch/powerpc/xmon/xmon.c
@@ -3015,9 +3015,9 @@ dump_log_buf(void)
catch_memory_errors = 1;
sync();
- kmsg_dump_rewind_nolock(&iter);
+ kmsg_dump_rewind(&iter);
xmon_start_pagination();
- while (kmsg_dump_get_line_nolock(&iter, false, buf, sizeof(buf), &len)) {
+ while (kmsg_dump_get_line(&iter, false, buf, sizeof(buf), &len)) {
buf[len] = '\0';
printf("%s", buf);
}
diff --git a/include/linux/kmsg_dump.h b/include/linux/kmsg_dump.h
index 2fdb10ab1799..86673930c8ea 100644
--- a/include/linux/kmsg_dump.h
+++ b/include/linux/kmsg_dump.h
@@ -60,18 +60,13 @@ struct kmsg_dumper {
#ifdef CONFIG_PRINTK
void kmsg_dump(enum kmsg_dump_reason reason);
-bool kmsg_dump_get_line_nolock(struct kmsg_dumper_iter *iter, bool syslog,
- char *line, size_t size, size_t *len);
-
bool kmsg_dump_get_line(struct kmsg_dumper_iter *iter, bool syslog,
char *line, size_t size, size_t *len);
bool kmsg_dump_get_buffer(struct kmsg_dumper_iter *iter, bool syslog,
char *buf, size_t size, size_t *len_out);
-void kmsg_dump_rewind_nolock(struct kmsg_dumper_iter *iter);
-
-void kmsg_dump_rewind(struct kmsg_dumper_iter *dumper_iter);
+void kmsg_dump_rewind(struct kmsg_dumper_iter *iter);
int kmsg_dump_register(struct kmsg_dumper *dumper);
@@ -83,13 +78,6 @@ static inline void kmsg_dump(enum kmsg_dump_reason reason)
{
}
-static inline bool kmsg_dump_get_line_nolock(struct kmsg_dumper_iter *iter,
- bool syslog, const char *line,
- size_t size, size_t *len)
-{
- return false;
-}
-
static inline bool kmsg_dump_get_line(struct kmsg_dumper_iter *iter, bool syslog,
const char *line, size_t size, size_t *len)
{
@@ -102,10 +90,6 @@ static inline bool kmsg_dump_get_buffer(struct kmsg_dumper_iter *iter, bool sysl
return false;
}
-static inline void kmsg_dump_rewind_nolock(struct kmsg_dumper_iter *iter)
-{
-}
-
static inline void kmsg_dump_rewind(struct kmsg_dumper_iter *iter)
{
}
diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c
index 048baadd7a41..1f5c577b926e 100644
--- a/kernel/debug/kdb/kdb_main.c
+++ b/kernel/debug/kdb/kdb_main.c
@@ -2182,8 +2182,8 @@ static int kdb_dmesg(int argc, const char **argv)
kdb_set(2, setargs);
}
- kmsg_dump_rewind_nolock(&iter);
- while (kmsg_dump_get_line_nolock(&iter, 1, NULL, 0, NULL))
+ kmsg_dump_rewind(&iter);
+ while (kmsg_dump_get_line(&iter, 1, NULL, 0, NULL))
n++;
if (lines < 0) {
@@ -2215,8 +2215,8 @@ static int kdb_dmesg(int argc, const char **argv)
if (skip >= n || skip < 0)
return 0;
- kmsg_dump_rewind_nolock(&iter);
- while (kmsg_dump_get_line_nolock(&iter, 1, buf, sizeof(buf), &len)) {
+ kmsg_dump_rewind(&iter);
+ while (kmsg_dump_get_line(&iter, 1, buf, sizeof(buf), &len)) {
if (skip) {
skip--;
continue;
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index dde1696d7564..031ce3f00141 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -3387,7 +3387,7 @@ void kmsg_dump(enum kmsg_dump_reason reason)
}
/**
- * kmsg_dump_get_line_nolock - retrieve one kmsg log line (unlocked version)
+ * kmsg_dump_get_line - retrieve one kmsg log line
* @iter: kmsg dumper iterator
* @syslog: include the "<4>" prefixes
* @line: buffer to copy the line to
@@ -3402,18 +3402,18 @@ void kmsg_dump(enum kmsg_dump_reason reason)
*
* 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_iter *iter, bool syslog,
- char *line, size_t size, size_t *len)
+bool kmsg_dump_get_line(struct kmsg_dumper_iter *iter, bool syslog,
+ char *line, size_t size, size_t *len)
{
struct printk_info info;
unsigned int line_count;
struct printk_record r;
+ unsigned long flags;
size_t l = 0;
bool ret = false;
+ printk_safe_enter_irqsave(flags);
prb_rec_init_rd(&r, &info, line, size);
if (!iter->active)
@@ -3437,40 +3437,11 @@ bool kmsg_dump_get_line_nolock(struct kmsg_dumper_iter *iter, bool syslog,
iter->cur_seq = r.info->seq + 1;
ret = true;
out:
+ printk_safe_exit_irqrestore(flags);
if (len)
*len = l;
return ret;
}
-
-/**
- * kmsg_dump_get_line - retrieve one kmsg log line
- * @iter: kmsg dumper iterator
- * @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_iter *iter, bool syslog,
- char *line, size_t size, size_t *len)
-{
- unsigned long flags;
- bool ret;
-
- printk_safe_enter_irqsave(flags);
- ret = kmsg_dump_get_line_nolock(iter, syslog, line, size, len);
- printk_safe_exit_irqrestore(flags);
-
- return ret;
-}
EXPORT_SYMBOL_GPL(kmsg_dump_get_line);
/**
@@ -3559,22 +3530,6 @@ bool kmsg_dump_get_buffer(struct kmsg_dumper_iter *iter, bool syslog,
}
EXPORT_SYMBOL_GPL(kmsg_dump_get_buffer);
-/**
- * kmsg_dump_rewind_nolock - reset the iterator (unlocked version)
- * @iter: kmsg dumper iterator
- *
- * 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_iter *iter)
-{
- iter->cur_seq = latched_seq_read_nolock(&clear_seq);
- iter->next_seq = prb_next_seq(prb);
-}
-
/**
* kmsg_dump_rewind - reset the iterator
* @iter: kmsg dumper iterator
@@ -3588,7 +3543,8 @@ void kmsg_dump_rewind(struct kmsg_dumper_iter *iter)
unsigned long flags;
printk_safe_enter_irqsave(flags);
- kmsg_dump_rewind_nolock(iter);
+ iter->cur_seq = latched_seq_read_nolock(&clear_seq);
+ iter->next_seq = prb_next_seq(prb);
printk_safe_exit_irqrestore(flags);
}
EXPORT_SYMBOL_GPL(kmsg_dump_rewind);
--
2.43.0
|
