Re: [PATCH v3 3/3] printk: use the lockless ringbuffer

From: John Ogness
Date: Fri Jul 03 2020 - 07:54:53 EST


On 2020-07-02, lijiang <lijiang@xxxxxxxxxx> wrote:
> About the VMCOREINFO part, I made some tests based on the kernel patch
> v3, the makedumpfile and crash-utility can work as expected with your
> patch(userspace patch), but, unfortunately, the
> vmcore-dmesg(kexec-tools) can't correctly read the printk ring buffer
> information, and get the following error:
>
> "Missing the log_buf symbol"
>
> The kexec-tools(vmcore-dmesg) should also have a similar patch, just like
> in the makedumpfile and crash-utility.

A patched kexec-tools is available here [0].

I did not test using 32-bit dumps on 64-bit machines and vice versa. But
it should work.

John Ogness

[0] https://github.com/Linutronix/kexec-tools.git (printk branch)