On Fri 2019-11-22 12:26:08, glider@xxxxxxxxxx wrote:
> Insert KMSAN hooks that check for potential memory errors and/or make
> necessary bookkeeping changes:
> - allocate/split/deallocate metadata pages in
> alloc_pages()/split_page()/free_page();
> - clear page shadow and origins in clear_page(), copy_user_highpage();
> - copy page metadata in copy_highpage(), wp_page_copy();
> - handle vmap()/vunmap()/iounmap();
> - handle task creation and deletion;
> - initialize result of vscnprintf() in vprintk_store();
> - call softirq entry/exit hooks in kernel/softirq.c;
> - check/initialize memory sent to/read from USB, I2C, and network
>
> Signed-off-by: Alexander Potapenko <glider@xxxxxxxxxx>
> diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
> index ca65327a6de8..c9ef7fb0906f 100644
> --- a/kernel/printk/printk.c
> +++ b/kernel/printk/printk.c
> @@ -1915,6 +1915,12 @@ int vprintk_store(int facility, int level,
> * prefix which might be passed-in as a parameter.
> */
> text_len = vscnprintf(text, sizeof(textbuf), fmt, args);
> + /*
> + * If any of vscnprintf() arguments is uninitialized, KMSAN will report
> + * one or more errors and also probably mark text_len as uninitialized.
> + * Initialize |text_len| to prevent the errors from spreading further.
> + */
> + text_len = KMSAN_INIT_VALUE(text_len);
>
> /* mark and strip a trailing newline */
> if (text_len && text[text_len-1] == '\n') {
Acked-by: Petr Mladek <pmladek@xxxxxxxx> # for printk.c
Best Regards,
Petr
