On (10/09/18 15:05), Petr Mladek wrote:
> >
> > Yeah, I think we gonna have problems even with a 4G logbuf and a 32-bit
> > user-space doing syslog(int len).
> >
> > I agree on the "not motivated enough" part ;)
>
> OK, I have pushed an updated patch that has the limit 2GB
> into printk.git, for-4.20 branch.
>
> Note that it is slightly different than the yesterday's proposal.
> I made a mistake in testing and still compared with UNIT_MAX.
>
> The pushed version can be seen at
> https://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk.git/commit/?h=for-4.20&id=e6fe3e5b7d16e8f146a4ae7fe481bc6e97acde1e
---
> +#define LOG_BUF_LEN_MAX (u32)(1 << 31)
[..]
> + if (size > (u64)LOG_BUF_LEN_MAX) {
> + size = (u64)LOG_BUF_LEN_MAX;
> + pr_err("log_buf over 2G is not supported.\n");
> + }
Why not INT_MAX?
> + pr_info("log_buf_len: %u bytes\n", log_buf_len);
> + pr_info("early log buf free: %u(%u%%)\n",
> free, (free * 100) / __LOG_BUF_LEN);
Can 'free * 100' overflow?
-ss
