diff options
Diffstat (limited to 'kernel/printk/printk.c')
| -rw-r--r-- | kernel/printk/printk.c | 44 |
1 files changed, 29 insertions, 15 deletions
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index 221229cf0190..99b7a2d87b6a 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -297,6 +297,34 @@ static u32 log_next(u32 idx) return idx + msg->len; } +/* check whether there is enough free space for the given message */ +static int logbuf_has_space(u32 msg_size) +{ + u32 free; + + if (log_next_idx > log_first_idx) + free = max(log_buf_len - log_next_idx, log_first_idx); + else + free = log_first_idx - log_next_idx; + + /* + * We need space also for an empty header that signalizes wrapping + * of the buffer. + */ + return free >= msg_size + sizeof(struct printk_log); +} + +static void log_make_free_space(u32 msg_size) +{ + while (log_first_seq < log_next_seq) { + if (logbuf_has_space(msg_size)) + return; + /* drop old messages until we have enough continuous space */ + log_first_idx = log_next(log_first_idx); + log_first_seq++; + } +} + /* insert record into the buffer, discard old ones, update heads */ static void log_store(int facility, int level, enum log_flags flags, u64 ts_nsec, @@ -311,21 +339,7 @@ static void log_store(int facility, int level, pad_len = (-size) & (LOG_ALIGN - 1); size += pad_len; - while (log_first_seq < log_next_seq) { - u32 free; - - if (log_next_idx > log_first_idx) - free = max(log_buf_len - log_next_idx, log_first_idx); - else - free = log_first_idx - log_next_idx; - - if (free >= size + sizeof(struct printk_log)) - break; - - /* drop old messages until we have enough contiuous space */ - log_first_idx = log_next(log_first_idx); - log_first_seq++; - } + log_make_free_space(size); if (log_next_idx + size + sizeof(struct printk_log) > log_buf_len) { /* |