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authorNamit Gupta <gupta.namit@samsung.com>2018-06-20 19:26:19 +0530
committerPetr Mladek <pmladek@suse.com>2018-06-27 16:16:28 +0200
commit63842c21347ecf4685d6ec008e667e61b0ead6e5 (patch)
tree54ddba7dade806fd43715c11bd4c2816042c3a3e /kernel/printk
parent22eceb8bf3e8f1f9b2f566062d06b25807725d7f (diff)
downloadlinux-63842c21347ecf4685d6ec008e667e61b0ead6e5.tar.bz2
printk: Remove unnecessary kmalloc() from syslog during clear
When the request is only for clearing logs, there is no need for allocation/deallocation. Only the indexes need to be reset and returned. Rest of the patch is mostly made up of changes because of indention. Link: http://lkml.kernel.org/r/20180620135951epcas5p3bd2a8f25ec689ca333bce861b527dba2~54wyKcT0_3155531555epcas5p3y@epcas5p3.samsung.com Cc: linux-kernel@vger.kernel.org Cc: pankaj.m@samsung.com Cc: a.sahrawat@samsung.com Signed-off-by: Namit Gupta <gupta.namit@samsung.com> Signed-off-by: Himanshu Maithani <himanshu.m@samsung.com> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
Diffstat (limited to 'kernel/printk')
-rw-r--r--kernel/printk/printk.c109
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;
}
}