*/
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 {
*/
static DEFINE_RAW_SPINLOCK(logbuf_lock);
+#ifdef CONFIG_PRINTK
/* 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;
/* index and sequence number of the next record to store in the buffer */
static u64 log_next_seq;
-#ifdef CONFIG_PRINTK
static u32 log_next_idx;
+/* the next printk record to write to the console */
+static u64 console_seq;
+static u32 console_idx;
+static enum log_flags console_prev;
+
/* the next printk record to read after the last 'clear' command */
static u64 clear_seq;
static u32 clear_idx;
-#define LOG_LINE_MAX 1024
+#define PREFIX_MAX 32
+#define LOG_LINE_MAX 1024 - PREFIX_MAX
/* record buffer */
#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
struct devkmsg_user {
u64 seq;
u32 idx;
+ enum log_flags prev;
struct mutex lock;
char buf[8192];
};
line = buf;
for (i = 0; i < count; i++) {
- if (copy_from_user(line, iv[i].iov_base, iv[i].iov_len))
+ if (copy_from_user(line, iv[i].iov_base, iv[i].iov_len)) {
+ ret = -EFAULT;
goto out;
+ }
line += iv[i].iov_len;
}
struct log *msg;
u64 ts_usec;
size_t i;
+ char cont = '-';
size_t len;
ssize_t ret;
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) {
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;
}
msg = log_from_idx(user->idx);
ts_usec = msg->ts_nsec;
do_div(ts_usec, 1000);
- len = sprintf(user->buf, "%u,%llu,%llu;",
- (msg->facility << 3) | msg->level, user->seq, ts_usec);
+
+ /*
+ * If we couldn't merge continuation line fragments during the print,
+ * export the stored flags to allow an optional external merge of the
+ * records. Merging the records isn't always neccessarily correct, like
+ * when we hit a race during printing. In most cases though, it produces
+ * better readable output. 'c' in the record flags mark the first
+ * fragment of a line, '+' the following.
+ */
+ if (msg->flags & LOG_CONT && !(user->prev & LOG_CONT))
+ cont = 'c';
+ else if ((msg->flags & LOG_CONT) ||
+ ((user->prev & LOG_CONT) && !(msg->flags & LOG_PREFIX)))
+ cont = '+';
+
+ len = sprintf(user->buf, "%u,%llu,%llu,%c;",
+ (msg->facility << 3) | msg->level,
+ user->seq, ts_usec, cont);
+ user->prev = msg->flags;
/* escape non-printable characters */
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;
continue;
}
- if (c < ' ' || c >= 128) {
+ if (c < ' ' || c >= 127 || c == '\\') {
len += sprintf(user->buf + len, "\\x%02x", c);
continue;
}
user->idx = log_next(user->idx);
user->seq++;
- raw_spin_unlock(&logbuf_lock);
+ raw_spin_unlock_irq(&logbuf_lock);
if (len > count) {
ret = -EINVAL;
if (offset)
return -ESPIPE;
- raw_spin_lock(&logbuf_lock);
+ raw_spin_lock_irq(&logbuf_lock);
switch (whence) {
case SEEK_SET:
/* the first record */
default:
ret = -EINVAL;
}
- raw_spin_unlock(&logbuf_lock);
+ raw_spin_unlock_irq(&logbuf_lock);
return ret;
}
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;
}
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;
VMCOREINFO_SYMBOL(log_buf_len);
VMCOREINFO_SYMBOL(log_first_idx);
VMCOREINFO_SYMBOL(log_next_idx);
+ /*
+ * Export struct log size and field offsets. User space tools can
+ * parse it and detect any changes to structure down the line.
+ */
+ VMCOREINFO_STRUCT_SIZE(log);
+ VMCOREINFO_OFFSET(log, ts_nsec);
+ VMCOREINFO_OFFSET(log, len);
+ VMCOREINFO_OFFSET(log, text_len);
+ VMCOREINFO_OFFSET(log, dict_len);
}
#endif
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++;
}
}
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;
if (buf) {
if (print_prefix(msg, syslog, NULL) +
- text_len + 1>= size - len)
+ 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);
struct log *msg;
int len = 0;
- text = kmalloc(LOG_LINE_MAX, GFP_KERNEL);
+ text = kmalloc(LOG_LINE_MAX + PREFIX_MAX, GFP_KERNEL);
if (!text)
return -ENOMEM;
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 + PREFIX_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);
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);
char *text;
int len = 0;
- text = kmalloc(LOG_LINE_MAX, GFP_KERNEL);
+ text = kmalloc(LOG_LINE_MAX + PREFIX_MAX, GFP_KERNEL);
if (!text)
return -ENOMEM;
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 */
*/
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);
+ prev = msg->flags;
idx = log_next(idx);
seq++;
}
/* 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);
+ prev = msg->flags;
idx = log_next(idx);
seq++;
}
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 + PREFIX_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))
/* messages are gone, move to next one */
seq = log_first_seq;
idx = log_first_idx;
+ prev = 0;
}
}
}
{
bool clear = false;
static int saved_console_loglevel = -1;
- static DEFINE_MUTEX(syslog_mutex);
int error;
error = check_syslog_permissions(type, 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:
/* 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) {
/*
*/
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;
return do_syslog(type, buf, len, SYSLOG_FROM_CALL);
}
-#ifdef CONFIG_KGDB_KDB
-/* kdb dmesg command needs access to the syslog buffer. do_syslog()
- * uses locks so it cannot be used during debugging. Just tell kdb
- * where the start and end of the physical and logical logs are. This
- * is equivalent to do_syslog(3).
- */
-void kdb_syslog_data(char *syslog_data[4])
-{
- syslog_data[0] = log_buf;
- syslog_data[1] = log_buf + log_buf_len;
- syslog_data[2] = log_buf + log_first_idx;
- syslog_data[3] = log_buf + log_next_idx;
-}
-#endif /* CONFIG_KGDB_KDB */
-
static bool __read_mostly ignore_loglevel;
static int __init ignore_loglevel_setup(char *str)
u64 ts_nsec; /* time of first print */
u8 level; /* log level of first message */
u8 facility; /* log level of first message */
+ enum log_flags flags; /* prefix, newline flags */
bool flushed:1; /* buffer sealed and committed */
} cont;
-static void cont_flush(void)
+static void cont_flush(enum log_flags flags)
{
if (cont.flushed)
return;
if (cont.len == 0)
return;
- log_store(cont.facility, cont.level, LOG_NOCONS, cont.ts_nsec,
- NULL, 0, cont.buf, cont.len);
-
- cont.flushed = true;
+ if (cont.cons) {
+ /*
+ * If a fragment of this line was directly flushed to the
+ * console; wait for the console to pick up the rest of the
+ * line. LOG_NOCONS suppresses a duplicated output.
+ */
+ log_store(cont.facility, cont.level, flags | LOG_NOCONS,
+ cont.ts_nsec, NULL, 0, cont.buf, cont.len);
+ cont.flags = flags;
+ cont.flushed = true;
+ } else {
+ /*
+ * If no fragment of this line ever reached the console,
+ * just submit it to the store and free the buffer.
+ */
+ log_store(cont.facility, cont.level, flags, 0,
+ NULL, 0, cont.buf, cont.len);
+ cont.len = 0;
+ }
}
static bool cont_add(int facility, int level, const char *text, size_t len)
return false;
if (cont.len + len > sizeof(cont.buf)) {
- cont_flush();
+ /* the line gets too long, split it up in separate records */
+ cont_flush(LOG_CONT);
return false;
}
cont.level = level;
cont.owner = current;
cont.ts_nsec = local_clock();
+ cont.flags = 0;
cont.cons = 0;
cont.flushed = false;
}
memcpy(cont.buf + cont.len, text, len);
cont.len += len;
+
+ if (cont.len > (sizeof(cont.buf) * 80) / 100)
+ cont_flush(LOG_CONT);
+
return true;
}
size_t textlen = 0;
size_t len;
- if (cont.cons == 0) {
+ if (cont.cons == 0 && (console_prev & LOG_NEWLINE)) {
textlen += print_time(cont.ts_nsec, text);
size -= textlen;
}
}
if (cont.flushed) {
- text[textlen++] = '\n';
+ if (cont.flags & LOG_NEWLINE)
+ text[textlen++] = '\n';
/* got everything, release buffer */
cont.len = 0;
}
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();
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);
}
/* mark and strip a trailing newline */
if (text_len && text[text_len-1] == '\n') {
text_len--;
- newline = true;
- }
-
- /* strip syslog prefix and extract log level or control flags */
- if (text[0] == '<' && text[1] && text[2] == '>') {
- switch (text[1]) {
- case '0' ... '7':
- if (level == -1)
- level = text[1] - '0';
- case 'd': /* KERN_DEFAULT */
- prefix = true;
- case 'c': /* KERN_CONT */
- text += 3;
- text_len -= 3;
+ lflags |= LOG_NEWLINE;
+ }
+
+ /* strip kernel syslog prefix and extract log level or control flags */
+ if (facility == 0) {
+ int kern_level = printk_get_level(text);
+
+ if (kern_level) {
+ const char *end_of_header = printk_skip_level(text);
+ switch (kern_level) {
+ case '0' ... '7':
+ if (level == -1)
+ level = kern_level - '0';
+ case 'd': /* KERN_DEFAULT */
+ lflags |= LOG_PREFIX;
+ case 'c': /* KERN_CONT */
+ break;
+ }
+ text_len -= end_of_header - text;
+ text = (char *)end_of_header;
}
}
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))
- cont_flush();
+ if (cont.len && (lflags & LOG_PREFIX || cont.owner != current))
+ cont_flush(LOG_NEWLINE);
/* 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;
* 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();
+ cont_flush(LOG_NEWLINE);
}
if (!stored)
- log_store(facility, level, LOG_DEFAULT, 0,
+ log_store(facility, level, lflags, 0,
dict, dictlen, text, text_len);
}
printed_len += text_len;
}
EXPORT_SYMBOL(printk);
-#else
+#else /* CONFIG_PRINTK */
+#define LOG_LINE_MAX 0
+#define PREFIX_MAX 0
#define LOG_LINE_MAX 0
+static u64 syslog_seq;
+static u32 syslog_idx;
+static u64 console_seq;
+static u32 console_idx;
+static enum log_flags syslog_prev;
+static u64 log_first_seq;
+static u32 log_first_idx;
+static u64 log_next_seq;
+static enum log_flags console_prev;
static struct cont {
size_t len;
size_t cons;
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 */
this_cpu_or(printk_pending, PRINTK_PENDING_WAKEUP);
}
-/* the next printk record to write to the console */
-static u64 console_seq;
-static u32 console_idx;
+static void console_cont_flush(char *text, size_t size)
+{
+ unsigned long flags;
+ size_t len;
+
+ raw_spin_lock_irqsave(&logbuf_lock, flags);
+
+ if (!cont.len)
+ goto out;
+
+ /*
+ * We still queue earlier records, likely because the console was
+ * busy. The earlier ones need to be printed before this one, we
+ * did not flush any fragment so far, so just let it queue up.
+ */
+ if (console_seq < log_next_seq && !cont.cons)
+ goto out;
+
+ len = cont_print_text(text, size);
+ raw_spin_unlock(&logbuf_lock);
+ stop_critical_timings();
+ call_console_drivers(cont.level, text, len);
+ start_critical_timings();
+ local_irq_restore(flags);
+ return;
+out:
+ raw_spin_unlock_irqrestore(&logbuf_lock, flags);
+}
/**
* console_unlock - unlock the console system
*/
void console_unlock(void)
{
- static char text[LOG_LINE_MAX];
+ static char text[LOG_LINE_MAX + PREFIX_MAX];
static u64 seen_seq;
unsigned long flags;
bool wake_klogd = false;
console_may_schedule = 0;
/* flush buffered message fragment immediately to console */
- raw_spin_lock_irqsave(&logbuf_lock, flags);
- if (cont.len && (cont.cons < cont.len || cont.flushed)) {
- size_t len;
-
- len = cont_print_text(text, sizeof(text));
- raw_spin_unlock(&logbuf_lock);
- stop_critical_timings();
- call_console_drivers(cont.level, text, len);
- start_critical_timings();
- local_irq_restore(flags);
- } else
- raw_spin_unlock_irqrestore(&logbuf_lock, flags);
-
+ console_cont_flush(text, sizeof(text));
again:
for (;;) {
struct log *msg;
/* 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)
*/
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;
+ console_prev = msg->flags;
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 */
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
}
/**
- * kmsg_dump_get_line - retrieve one kmsg log line
+ * kmsg_dump_get_line_nolock - retrieve one kmsg log line (unlocked version)
* @dumper: registered kmsg dumper
* @syslog: include the "<4>" prefixes
* @line: buffer to copy the line to
*
* 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(struct kmsg_dumper *dumper, bool syslog,
- char *line, size_t size, size_t *len)
+bool kmsg_dump_get_line_nolock(struct kmsg_dumper *dumper, bool syslog,
+ char *line, size_t size, size_t *len)
{
- unsigned long flags;
struct log *msg;
size_t l = 0;
bool ret = false;
if (!dumper->active)
goto out;
- raw_spin_lock_irqsave(&logbuf_lock, flags);
if (dumper->cur_seq < log_first_seq) {
/* messages are gone, move to first available one */
dumper->cur_seq = log_first_seq;
}
/* last entry */
- if (dumper->cur_seq >= log_next_seq) {
- raw_spin_unlock_irqrestore(&logbuf_lock, flags);
+ if (dumper->cur_seq >= log_next_seq)
goto out;
- }
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++;
ret = true;
- raw_spin_unlock_irqrestore(&logbuf_lock, flags);
out:
if (len)
*len = l;
return ret;
}
+
+/**
+ * kmsg_dump_get_line - retrieve one kmsg log line
+ * @dumper: registered kmsg dumper
+ * @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 *dumper, bool syslog,
+ char *line, size_t size, size_t *len)
+{
+ unsigned long flags;
+ bool ret;
+
+ raw_spin_lock_irqsave(&logbuf_lock, flags);
+ ret = kmsg_dump_get_line_nolock(dumper, syslog, line, size, len);
+ raw_spin_unlock_irqrestore(&logbuf_lock, flags);
+
+ return ret;
+}
EXPORT_SYMBOL_GPL(kmsg_dump_get_line);
/**
u32 idx;
u64 next_seq;
u32 next_idx;
+ enum log_flags prev;
size_t l = 0;
bool ret = false;
/* 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 */
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;
}
EXPORT_SYMBOL_GPL(kmsg_dump_get_buffer);
+/**
+ * kmsg_dump_rewind_nolock - reset the interator (unlocked version)
+ * @dumper: registered kmsg dumper
+ *
+ * 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 *dumper)
+{
+ dumper->cur_seq = clear_seq;
+ dumper->cur_idx = clear_idx;
+ dumper->next_seq = log_next_seq;
+ dumper->next_idx = log_next_idx;
+}
+
/**
* kmsg_dump_rewind - reset the interator
* @dumper: registered kmsg dumper
unsigned long flags;
raw_spin_lock_irqsave(&logbuf_lock, flags);
- dumper->cur_seq = clear_seq;
- dumper->cur_idx = clear_idx;
- dumper->next_seq = log_next_seq;
- dumper->next_idx = log_next_idx;
+ kmsg_dump_rewind_nolock(dumper);
raw_spin_unlock_irqrestore(&logbuf_lock, flags);
}
EXPORT_SYMBOL_GPL(kmsg_dump_rewind);
projects / deliverable / linux.git / blobdiff