Merge tag 'driver-core-3.5-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull printk fixes from Greg Kroah-Hartman:
"Here are some more printk fixes for 3.5-rc6. They resolve all known
outstanding issues with the printk changes that have been happening.
They have been tested by the people reporting the problems.
This hopefully should be it for the printk stuff for 3.5-final.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>"
* tag 'driver-core-3.5-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
kmsg: merge continuation records while printing
kmsg: /proc/kmsg - support reading of partial log records
kmsg: make sure all messages reach a newly registered boot console
kmsg: properly handle concurrent non-blocking read() from /proc/kmsg
kmsg: add the facility number to the syslog prefix
kmsg: escape the backslash character while exporting data
printk: replacing the raw_spin_lock/unlock with raw_spin_lock/unlock_irq
diff --git a/kernel/printk.c b/kernel/printk.c
index dba1821..177fa49 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -194,8 +194,10 @@
*/
enum log_flags {
- LOG_DEFAULT = 0,
- LOG_NOCONS = 1, /* already flushed, do not print to console */
+ 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 {
@@ -217,6 +219,8 @@
/* 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 size_t syslog_partial;
/* index and sequence number of the first record stored in the buffer */
static u64 log_first_seq;
@@ -430,20 +434,20 @@
ret = mutex_lock_interruptible(&user->lock);
if (ret)
return ret;
- raw_spin_lock(&logbuf_lock);
+ raw_spin_lock_irq(&logbuf_lock);
while (user->seq == log_next_seq) {
if (file->f_flags & O_NONBLOCK) {
ret = -EAGAIN;
- raw_spin_unlock(&logbuf_lock);
+ raw_spin_unlock_irq(&logbuf_lock);
goto out;
}
- raw_spin_unlock(&logbuf_lock);
+ raw_spin_unlock_irq(&logbuf_lock);
ret = wait_event_interruptible(log_wait,
user->seq != log_next_seq);
if (ret)
goto out;
- raw_spin_lock(&logbuf_lock);
+ raw_spin_lock_irq(&logbuf_lock);
}
if (user->seq < log_first_seq) {
@@ -451,7 +455,7 @@
user->idx = log_first_idx;
user->seq = log_first_seq;
ret = -EPIPE;
- raw_spin_unlock(&logbuf_lock);
+ raw_spin_unlock_irq(&logbuf_lock);
goto out;
}
@@ -465,7 +469,7 @@
for (i = 0; i < msg->text_len; i++) {
unsigned char c = log_text(msg)[i];
- if (c < ' ' || c >= 128)
+ if (c < ' ' || c >= 127 || c == '\\')
len += sprintf(user->buf + len, "\\x%02x", c);
else
user->buf[len++] = c;
@@ -489,7 +493,7 @@
continue;
}
- if (c < ' ' || c >= 128) {
+ if (c < ' ' || c >= 127 || c == '\\') {
len += sprintf(user->buf + len, "\\x%02x", c);
continue;
}
@@ -501,7 +505,7 @@
user->idx = log_next(user->idx);
user->seq++;
- raw_spin_unlock(&logbuf_lock);
+ raw_spin_unlock_irq(&logbuf_lock);
if (len > count) {
ret = -EINVAL;
@@ -528,7 +532,7 @@
if (offset)
return -ESPIPE;
- raw_spin_lock(&logbuf_lock);
+ raw_spin_lock_irq(&logbuf_lock);
switch (whence) {
case SEEK_SET:
/* the first record */
@@ -552,7 +556,7 @@
default:
ret = -EINVAL;
}
- raw_spin_unlock(&logbuf_lock);
+ raw_spin_unlock_irq(&logbuf_lock);
return ret;
}
@@ -566,14 +570,14 @@
poll_wait(file, &log_wait, wait);
- raw_spin_lock(&logbuf_lock);
+ raw_spin_lock_irq(&logbuf_lock);
if (user->seq < log_next_seq) {
/* return error when data has vanished underneath us */
if (user->seq < log_first_seq)
ret = POLLIN|POLLRDNORM|POLLERR|POLLPRI;
ret = POLLIN|POLLRDNORM;
}
- raw_spin_unlock(&logbuf_lock);
+ raw_spin_unlock_irq(&logbuf_lock);
return ret;
}
@@ -597,10 +601,10 @@
mutex_init(&user->lock);
- raw_spin_lock(&logbuf_lock);
+ raw_spin_lock_irq(&logbuf_lock);
user->idx = log_first_idx;
user->seq = log_first_seq;
- raw_spin_unlock(&logbuf_lock);
+ raw_spin_unlock_irq(&logbuf_lock);
file->private_data = user;
return 0;
@@ -818,15 +822,18 @@
static size_t print_prefix(const struct 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>", msg->level);
+ len += sprintf(buf, "<%u>", prefix);
} else {
len += 3;
- if (msg->level > 9)
- len++;
- if (msg->level > 99)
+ if (prefix > 999)
+ len += 3;
+ else if (prefix > 99)
+ len += 2;
+ else if (prefix > 9)
len++;
}
}
@@ -835,13 +842,26 @@
return len;
}
-static size_t msg_print_text(const struct log *msg, bool syslog,
- char *buf, size_t size)
+static size_t msg_print_text(const struct log *msg, enum log_flags prev,
+ bool syslog, char *buf, size_t size)
{
const char *text = 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;
@@ -859,16 +879,22 @@
text_len + 1>= size - len)
break;
- len += print_prefix(msg, syslog, buf + len);
+ if (prefix)
+ len += print_prefix(msg, syslog, buf + len);
memcpy(buf + len, text, text_len);
len += text_len;
- buf[len++] = '\n';
+ if (next || newline)
+ buf[len++] = '\n';
} else {
/* SYSLOG_ACTION_* buffer size only calculation */
- len += print_prefix(msg, syslog, NULL);
- len += text_len + 1;
+ if (prefix)
+ len += print_prefix(msg, syslog, NULL);
+ len += text_len;
+ if (next || newline)
+ len++;
}
+ prefix = true;
text = next;
} while (text);
@@ -887,22 +913,35 @@
while (size > 0) {
size_t n;
+ size_t skip;
raw_spin_lock_irq(&logbuf_lock);
if (syslog_seq < log_first_seq) {
/* messages are gone, move to first one */
syslog_seq = log_first_seq;
syslog_idx = log_first_idx;
+ syslog_prev = 0;
+ syslog_partial = 0;
}
if (syslog_seq == log_next_seq) {
raw_spin_unlock_irq(&logbuf_lock);
break;
}
+
+ skip = syslog_partial;
msg = log_from_idx(syslog_idx);
- n = msg_print_text(msg, true, text, LOG_LINE_MAX);
- if (n <= size) {
+ n = msg_print_text(msg, syslog_prev, true, text, LOG_LINE_MAX);
+ if (n - syslog_partial <= size) {
+ /* message fits into buffer, move forward */
syslog_idx = 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(&logbuf_lock);
@@ -910,17 +949,15 @@
if (!n)
break;
- len += n;
- size -= n;
- buf += n;
- n = copy_to_user(buf - n, text, n);
-
- if (n) {
- len -= n;
+ if (copy_to_user(buf, text + skip, n)) {
if (!len)
len = -EFAULT;
break;
}
+
+ len += n;
+ size -= n;
+ buf += n;
}
kfree(text);
@@ -941,6 +978,7 @@
u64 next_seq;
u64 seq;
u32 idx;
+ enum log_flags prev;
if (clear_seq < log_first_seq) {
/* messages are gone, move to first available one */
@@ -954,10 +992,11 @@
*/
seq = clear_seq;
idx = clear_idx;
+ prev = 0;
while (seq < log_next_seq) {
struct log *msg = log_from_idx(idx);
- len += msg_print_text(msg, true, NULL, 0);
+ len += msg_print_text(msg, prev, true, NULL, 0);
idx = log_next(idx);
seq++;
}
@@ -965,10 +1004,11 @@
/* move first record forward until length fits into the buffer */
seq = clear_seq;
idx = clear_idx;
+ prev = 0;
while (len > size && seq < log_next_seq) {
struct log *msg = log_from_idx(idx);
- len -= msg_print_text(msg, true, NULL, 0);
+ len -= msg_print_text(msg, prev, true, NULL, 0);
idx = log_next(idx);
seq++;
}
@@ -977,17 +1017,19 @@
next_seq = log_next_seq;
len = 0;
+ prev = 0;
while (len >= 0 && seq < next_seq) {
struct log *msg = log_from_idx(idx);
int textlen;
- textlen = msg_print_text(msg, true, text, LOG_LINE_MAX);
+ textlen = msg_print_text(msg, prev, true, text, LOG_LINE_MAX);
if (textlen < 0) {
len = textlen;
break;
}
idx = log_next(idx);
seq++;
+ prev = msg->flags;
raw_spin_unlock_irq(&logbuf_lock);
if (copy_to_user(buf + len, text, textlen))
@@ -1000,6 +1042,7 @@
/* messages are gone, move to next one */
seq = log_first_seq;
idx = log_first_idx;
+ prev = 0;
}
}
}
@@ -1018,7 +1061,6 @@
{
bool clear = false;
static int saved_console_loglevel = -1;
- static DEFINE_MUTEX(syslog_mutex);
int error;
error = check_syslog_permissions(type, from_file);
@@ -1045,17 +1087,11 @@
error = -EFAULT;
goto out;
}
- error = mutex_lock_interruptible(&syslog_mutex);
- if (error)
- goto out;
error = wait_event_interruptible(log_wait,
syslog_seq != log_next_seq);
- if (error) {
- mutex_unlock(&syslog_mutex);
+ if (error)
goto out;
- }
error = syslog_print(buf, len);
- mutex_unlock(&syslog_mutex);
break;
/* Read/clear last kernel messages */
case SYSLOG_ACTION_READ_CLEAR:
@@ -1111,6 +1147,8 @@
/* messages are gone, move to first one */
syslog_seq = log_first_seq;
syslog_idx = log_first_idx;
+ syslog_prev = 0;
+ syslog_partial = 0;
}
if (from_file) {
/*
@@ -1120,19 +1158,20 @@
*/
error = log_next_idx - syslog_idx;
} else {
- u64 seq;
- u32 idx;
+ u64 seq = syslog_seq;
+ u32 idx = syslog_idx;
+ enum log_flags prev = syslog_prev;
error = 0;
- seq = syslog_seq;
- idx = syslog_idx;
while (seq < log_next_seq) {
struct log *msg = log_from_idx(idx);
- error += msg_print_text(msg, true, NULL, 0);
+ error += msg_print_text(msg, prev, true, NULL, 0);
idx = log_next(idx);
seq++;
+ prev = msg->flags;
}
+ error -= syslog_partial;
}
raw_spin_unlock_irq(&logbuf_lock);
break;
@@ -1400,10 +1439,9 @@
static char textbuf[LOG_LINE_MAX];
char *text = textbuf;
size_t text_len;
+ enum log_flags lflags = 0;
unsigned long flags;
int this_cpu;
- bool newline = false;
- bool prefix = false;
int printed_len = 0;
boot_delay_msec();
@@ -1442,7 +1480,7 @@
recursion_bug = 0;
printed_len += strlen(recursion_msg);
/* emit KERN_CRIT message */
- log_store(0, 2, LOG_DEFAULT, 0,
+ log_store(0, 2, LOG_PREFIX|LOG_NEWLINE, 0,
NULL, 0, recursion_msg, printed_len);
}
@@ -1455,7 +1493,7 @@
/* mark and strip a trailing newline */
if (text_len && text[text_len-1] == '\n') {
text_len--;
- newline = true;
+ lflags |= LOG_NEWLINE;
}
/* strip syslog prefix and extract log level or control flags */
@@ -1465,7 +1503,7 @@
if (level == -1)
level = text[1] - '0';
case 'd': /* KERN_DEFAULT */
- prefix = true;
+ lflags |= LOG_PREFIX;
case 'c': /* KERN_CONT */
text += 3;
text_len -= 3;
@@ -1475,22 +1513,20 @@
if (level == -1)
level = default_message_loglevel;
- if (dict) {
- prefix = true;
- newline = true;
- }
+ if (dict)
+ lflags |= LOG_PREFIX|LOG_NEWLINE;
- if (!newline) {
+ if (!(lflags & LOG_NEWLINE)) {
/*
* Flush the conflicting buffer. An earlier newline was missing,
* or another task also prints continuation lines.
*/
- if (cont.len && (prefix || cont.owner != current))
+ if (cont.len && (lflags & LOG_PREFIX || cont.owner != current))
cont_flush();
/* buffer line if possible, otherwise store it right away */
if (!cont_add(facility, level, text, text_len))
- log_store(facility, level, LOG_DEFAULT, 0,
+ log_store(facility, level, lflags | LOG_CONT, 0,
dict, dictlen, text, text_len);
} else {
bool stored = false;
@@ -1502,13 +1538,13 @@
* flush it out and store this line separately.
*/
if (cont.len && cont.owner == current) {
- if (!prefix)
+ if (!(lflags & LOG_PREFIX))
stored = cont_add(facility, level, text, text_len);
cont_flush();
}
if (!stored)
- log_store(facility, level, LOG_DEFAULT, 0,
+ log_store(facility, level, lflags, 0,
dict, dictlen, text, text_len);
}
printed_len += text_len;
@@ -1607,8 +1643,8 @@
static struct 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, bool syslog,
- char *buf, size_t size) { return 0; }
+static size_t msg_print_text(const struct 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; }
#endif /* CONFIG_PRINTK */
@@ -1884,6 +1920,7 @@
/* the next printk record to write to the console */
static u64 console_seq;
static u32 console_idx;
+static enum log_flags console_prev;
/**
* console_unlock - unlock the console system
@@ -1944,6 +1981,7 @@
/* messages are gone, move to first one */
console_seq = log_first_seq;
console_idx = log_first_idx;
+ console_prev = 0;
}
skip:
if (console_seq == log_next_seq)
@@ -1957,14 +1995,21 @@
*/
console_idx = log_next(console_idx);
console_seq++;
+ /*
+ * We will get here again when we register a new
+ * CON_PRINTBUFFER console. Clear the flag so we
+ * will properly dump everything later.
+ */
+ msg->flags &= ~LOG_NOCONS;
goto skip;
}
level = msg->level;
- len = msg_print_text(msg, false, text, sizeof(text));
-
+ len = msg_print_text(msg, console_prev, false,
+ text, sizeof(text));
console_idx = log_next(console_idx);
console_seq++;
+ console_prev = msg->flags;
raw_spin_unlock(&logbuf_lock);
stop_critical_timings(); /* don't trace print latency */
@@ -2227,6 +2272,7 @@
raw_spin_lock_irqsave(&logbuf_lock, flags);
console_seq = syslog_seq;
console_idx = syslog_idx;
+ console_prev = syslog_prev;
raw_spin_unlock_irqrestore(&logbuf_lock, flags);
/*
* We're about to replay the log buffer. Only do this to the
@@ -2520,8 +2566,7 @@
}
msg = log_from_idx(dumper->cur_idx);
- l = msg_print_text(msg, syslog,
- line, size);
+ l = msg_print_text(msg, 0, syslog, line, size);
dumper->cur_idx = log_next(dumper->cur_idx);
dumper->cur_seq++;
@@ -2561,6 +2606,7 @@
u32 idx;
u64 next_seq;
u32 next_idx;
+ enum log_flags prev;
size_t l = 0;
bool ret = false;
@@ -2583,23 +2629,27 @@
/* calculate length of entire buffer */
seq = dumper->cur_seq;
idx = dumper->cur_idx;
+ prev = 0;
while (seq < dumper->next_seq) {
struct log *msg = log_from_idx(idx);
- l += msg_print_text(msg, true, NULL, 0);
+ l += msg_print_text(msg, prev, true, NULL, 0);
idx = 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 log *msg = log_from_idx(idx);
- l -= msg_print_text(msg, true, NULL, 0);
+ l -= msg_print_text(msg, prev, true, NULL, 0);
idx = log_next(idx);
seq++;
+ prev = msg->flags;
}
/* last message in next interation */
@@ -2607,14 +2657,14 @@
next_idx = idx;
l = 0;
+ prev = 0;
while (seq < dumper->next_seq) {
struct log *msg = log_from_idx(idx);
- l += msg_print_text(msg, syslog,
- buf + l, size - l);
-
+ l += msg_print_text(msg, prev, syslog, buf + l, size - l);
idx = log_next(idx);
seq++;
+ prev = msg->flags;
}
dumper->next_seq = next_seq;