On (09/19/18 01:17), zhe...@windriver.com wrote:
> Add KBUILD_MODNAME to make prints more clear.

No strong opinion. I'm OK with this change.

> And use 'unsigned int' intead of 'unsigned' according to
> checkpatch.pl's suggestion.

I don't think that "unsigned int" is the right thing to use there.

>               if (console_seq < log_first_seq) {
>                       len = sprintf(text, "** %u printk messages dropped 
> **\n",
> -                                   (unsigned)(log_first_seq - console_seq));
> +                                (unsigned int)(log_first_seq - console_seq));

Both log_first_seq and console_seq are u64.

        log_first_seq - console_seq

thus, *in theory*, can be larger than "unsigned int". So I'd just avoid cast
and use an appropriate for u64 %llu sprintf() specifier. Something like below,
perhaps:

---

diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index f73ea9dd6f46..4b8c5832bf14 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -2408,8 +2408,9 @@ void console_unlock(void)
                printk_safe_enter_irqsave(flags);
                raw_spin_lock(&logbuf_lock);
                if (console_seq < log_first_seq) {
-                       len = sprintf(text, "** %u printk messages dropped 
**\n",
-                                  (unsigned int)(log_first_seq - console_seq));
+                       len = sprintf(text,
+                                     "** %llu printk messages dropped **\n",
+                                     log_first_seq - console_seq);
 
                        /* messages are gone, move to first one */
                        console_seq = log_first_seq;

---

Steven, Petr, any objections?

        -ss

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