Re: [PATCH v5 4/4] printk: Give error on attempt to set log buffer length to over 4G

[Sergey Senozhatsky]

On (10/08/18 15:59), Petr Mladek wrote:
> I tried this patch with log_buf_len=5G. The kernel did not crash
> but dmesg shown some mess. There are several 32-bit variables
> to store the size, for example:
> 
> static u32 log_buf_len = __LOG_BUF_LEN;
> u32 log_buf_len_get(void)
> static u32 log_first_idx;
> static u32 log_next_idx;
> 
> I guess that the code somewhere does not detect an overflows
> correctly.
> 
> I am not motivated enought to add support for such huge message
> buffer. Therefore I suggest to limit it to 32G for now.

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 ;)

	-ss