When the request is only for clearing logs, there is no need for buffer
allocation.
So, the indexes could be reset and returned. This will save unnecessary
kmalloc/kfree
calls also.
Signed-off-by: Namit Gupta <gupta.na...@samsung.com>
Signed-off-by: Himanshu Maithani <himansh...@samsung.com>
---
kernel/printk/printk.c | 111 ++++++++++++++++++++++++++-----------------------
1 file changed, 60 insertions(+), 51 deletions(-)
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 512f7c2..53952ce 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -1348,71 +1348,80 @@ 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);
-
- len += msg_print_text(msg, true, NULL, 0);
- idx = log_next(idx);
- seq++;
- }
+ /*
+ * 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);
- /* 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++;
- }
+ /* 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);
- /* last message fitting into this dump */
- next_seq = log_next_seq;
+ len -= msg_print_text(msg, true, NULL, 0);
+ idx = log_next(idx);
+ seq++;
+ }
- len = 0;
- while (len >= 0 && seq < next_seq) {
- struct printk_log *msg = log_from_idx(idx);
- int textlen;
+ /* last message fitting into this dump */
+ next_seq = log_next_seq;
- textlen = msg_print_text(msg, true, text,
- LOG_LINE_MAX + PREFIX_MAX);
- if (textlen < 0) {
- len = textlen;
- break;
- }
- idx = log_next(idx);
- seq++;
+ len = 0;
+ while (len >= 0 && seq < next_seq) {
+ struct printk_log *msg = log_from_idx(idx);
+ int textlen;
- logbuf_unlock_irq();
- if (copy_to_user(buf + len, text, textlen))
- len = -EFAULT;
- else
- len += textlen;
- logbuf_lock_irq();
+ textlen = msg_print_text(msg, true, text,
+ LOG_LINE_MAX + PREFIX_MAX);
+ if (textlen < 0) {
+ len = textlen;
+ break;
+ }
+ idx = log_next(idx);
+ seq++;
- if (seq < log_first_seq) {
- /* messages are gone, move to next one */
- seq = log_first_seq;
- idx = log_first_idx;
- }
+ 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;
}
}
--
1.9.1
