diff options
| -rw-r--r-- | kernel/printk.c | 51 |
1 files changed, 37 insertions, 14 deletions
diff --git a/kernel/printk.c b/kernel/printk.c index ff05361962e..cdfba44fedf 100644 --- a/kernel/printk.c +++ b/kernel/printk.c @@ -862,26 +862,49 @@ static int syslog_print(char __user *buf, int size) { char *text; struct log *msg; - int len; + int len = 0; text = kmalloc(LOG_LINE_MAX, GFP_KERNEL); if (!text) return -ENOMEM; - 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; - } - msg = log_from_idx(syslog_idx); - len = msg_print_text(msg, true, text, LOG_LINE_MAX); - syslog_idx = log_next(syslog_idx); - syslog_seq++; - raw_spin_unlock_irq(&logbuf_lock); + while (size > 0) { + size_t n; + + 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; + } + if (syslog_seq == log_next_seq) { + raw_spin_unlock_irq(&logbuf_lock); + break; + } + msg = log_from_idx(syslog_idx); + n = msg_print_text(msg, true, text, LOG_LINE_MAX); + if (n <= size) { + syslog_idx = log_next(syslog_idx); + syslog_seq++; + } else + n = 0; + raw_spin_unlock_irq(&logbuf_lock); + + if (!n) + break; - if (len > 0 && copy_to_user(buf, text, len)) - len = -EFAULT; + len += n; + size -= n; + buf += n; + n = copy_to_user(buf - n, text, n); + + if (n) { + len -= n; + if (!len) + len = -EFAULT; + break; + } + } kfree(text); return len; |