summaryrefslogtreecommitdiffstats
path: root/kernel/printk.c
diff options
context:
space:
mode:
Diffstat (limited to 'kernel/printk.c')
-rw-r--r--kernel/printk.c202
1 files changed, 126 insertions, 76 deletions
diff --git a/kernel/printk.c b/kernel/printk.c
index dba18211685..177fa49357a 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -194,8 +194,10 @@ static int console_may_schedule;
*/
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 @@ static DEFINE_RAW_SPINLOCK(logbuf_lock);
/* 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 @@ static ssize_t devkmsg_read(struct file *file, char __user *buf,
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 @@ static ssize_t devkmsg_read(struct file *file, char __user *buf,
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 @@ static ssize_t devkmsg_read(struct file *file, char __user *buf,
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 @@ static ssize_t devkmsg_read(struct file *file, char __user *buf,
continue;
}
- if (c < ' ' || c >= 128) {
+ if (c < ' ' || c >= 127 || c == '\\') {
len += sprintf(user->buf + len, "\\x%02x", c);
continue;
}
@@ -501,7 +505,7 @@ static ssize_t devkmsg_read(struct file *file, char __user *buf,
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 @@ static loff_t devkmsg_llseek(struct file *file, loff_t offset, int whence)
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 @@ static loff_t devkmsg_llseek(struct file *file, loff_t offset, int whence)
default:
ret = -EINVAL;
}
- raw_spin_unlock(&logbuf_lock);
+ raw_spin_unlock_irq(&logbuf_lock);
return ret;
}
@@ -566,14 +570,14 @@ static unsigned int devkmsg_poll(struct file *file, poll_table *wait)
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 @@ static int devkmsg_open(struct inode *inode, struct file *file)
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_time(u64 ts, char *buf)
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 @@ static size_t print_prefix(const struct log *msg, bool syslog, char *buf)
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 @@ static size_t msg_print_text(const struct log *msg, bool syslog,
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 @@ static int syslog_print(char __user *buf, int size)
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 @@ static int syslog_print(char __user *buf, int size)
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 @@ static int syslog_print_all(char __user *buf, int size, bool clear)
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 @@ static int syslog_print_all(char __user *buf, int size, bool clear)
*/
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 @@ static int syslog_print_all(char __user *buf, int size, bool clear)
/* 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 @@ static int syslog_print_all(char __user *buf, int size, bool clear)
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 @@ static int syslog_print_all(char __user *buf, int size, bool clear)
/* messages are gone, move to next one */
seq = log_first_seq;
idx = log_first_idx;
+ prev = 0;
}
}
}
@@ -1018,7 +1061,6 @@ int do_syslog(int type, char __user *buf, int len, bool from_file)
{
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 @@ int do_syslog(int type, char __user *buf, int len, bool from_file)
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 @@ int do_syslog(int type, char __user *buf, int len, bool from_file)
/* 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 @@ int do_syslog(int type, char __user *buf, int len, bool from_file)
*/
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 @@ asmlinkage int vprintk_emit(int facility, int level,
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 @@ asmlinkage int vprintk_emit(int facility, int level,
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 @@ asmlinkage int vprintk_emit(int facility, int level,
/* 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 @@ asmlinkage int vprintk_emit(int facility, int level,
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 @@ asmlinkage int vprintk_emit(int facility, int level,
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 @@ asmlinkage int vprintk_emit(int facility, int level,
* 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 cont {
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 @@ void wake_up_klogd(void)
/* 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 @@ again:
/* 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 @@ skip:
*/
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 @@ void register_console(struct console *newcon)
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 @@ bool kmsg_dump_get_line(struct kmsg_dumper *dumper, bool syslog,
}
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 @@ bool kmsg_dump_get_buffer(struct kmsg_dumper *dumper, bool syslog,
u32 idx;
u64 next_seq;
u32 next_idx;
+ enum log_flags prev;
size_t l = 0;
bool ret = false;
@@ -2583,23 +2629,27 @@ bool kmsg_dump_get_buffer(struct kmsg_dumper *dumper, bool syslog,
/* 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 @@ bool kmsg_dump_get_buffer(struct kmsg_dumper *dumper, bool syslog,
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;
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-12-18 21:22:41 +0000