diff options
| -rw-r--r-- | kernel/printk/printk.c | 109 |
1 files changed, 58 insertions, 51 deletions
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index 3999c295d6f7..16b02cc51a14 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -1352,71 +1352,78 @@ static int syslog_print_all(char __user *buf, int size, bool clear) { char *text; int len = 0; + u64 next_seq; + u64 seq; + u32 idx; + + if (!buf) { + if (clear) { + logbuf_lock_irq(); + clear_seq = log_next_seq; + clear_idx = log_next_idx; + logbuf_unlock_irq(); + } + return 0; + } text = kmalloc(LOG_LINE_MAX + PREFIX_MAX, GFP_KERNEL); if (!text) return -ENOMEM; logbuf_lock_irq(); - if (buf) { - u64 next_seq; - u64 seq; - u32 idx; + /* + * Find first record that fits, including all following records, + * into the user-provided buffer for this dump. + */ + seq = clear_seq; + idx = clear_idx; + while (seq < log_next_seq) { + struct printk_log *msg = log_from_idx(idx); - /* - * Find first record that fits, including all following records, - * into the user-provided buffer for this dump. - */ - seq = clear_seq; - idx = clear_idx; - while (seq < log_next_seq) { - struct printk_log *msg = log_from_idx(idx); - - len += msg_print_text(msg, true, NULL, 0); - idx = log_next(idx); - seq++; - } + len += msg_print_text(msg, true, NULL, 0); + idx = log_next(idx); + seq++; + } - /* move first record forward until length fits into the buffer */ - seq = clear_seq; - idx = clear_idx; - while (len > size && seq < log_next_seq) { - struct printk_log *msg = log_from_idx(idx); + /* move first record forward until length fits into the buffer */ + seq = clear_seq; + idx = clear_idx; + while (len > size && seq < log_next_seq) { + struct printk_log *msg = log_from_idx(idx); - len -= msg_print_text(msg, true, NULL, 0); - idx = log_next(idx); - seq++; - } + len -= msg_print_text(msg, true, NULL, 0); + idx = log_next(idx); + seq++; + } - /* last message fitting into this dump */ - next_seq = log_next_seq; + /* last message fitting into this dump */ + next_seq = log_next_seq; - len = 0; - while (len >= 0 && seq < next_seq) { - struct printk_log *msg = log_from_idx(idx); - int textlen; + len = 0; + while (len >= 0 && seq < next_seq) { + struct printk_log *msg = log_from_idx(idx); + int textlen; - textlen = msg_print_text(msg, true, text, - LOG_LINE_MAX + PREFIX_MAX); - if (textlen < 0) { - len = textlen; - break; - } - idx = log_next(idx); - seq++; + textlen = msg_print_text(msg, true, text, + LOG_LINE_MAX + PREFIX_MAX); + if (textlen < 0) { + len = textlen; + break; + } + idx = log_next(idx); + seq++; - logbuf_unlock_irq(); - if (copy_to_user(buf + len, text, textlen)) - len = -EFAULT; - else - len += textlen; - logbuf_lock_irq(); + logbuf_unlock_irq(); + if (copy_to_user(buf + len, text, textlen)) + len = -EFAULT; + else + len += textlen; + logbuf_lock_irq(); - if (seq < log_first_seq) { - /* messages are gone, move to next one */ - seq = log_first_seq; - idx = log_first_idx; - } + if (seq < log_first_seq) { + /* messages are gone, move to next one */ + seq = log_first_seq; + idx = log_first_idx; } } |