Re: [PATCH v17 1/5] ring-buffer: Flush and stop persistent ring buffer on panic

[Geert Uytterhoeven]

On Wed, 22 Apr 2026 at 18:26, Masami Hiramatsu (Google)
<mhiramat@xxxxxxxxxx> wrote:
> From: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>
>
> On real hardware, panic and machine reboot may not flush hardware cache
> to memory. This means the persistent ring buffer, which relies on a
> coherent state of memory, may not have its events written to the buffer
> and they may be lost. Moreover, there may be inconsistency with the
> counters which are used for validation of the integrity of the
> persistent ring buffer which may cause all data to be discarded.
>
> To avoid this issue, stop recording of the ring buffer on panic and
> flush the cache of the ring buffer's memory.
>
> Fixes: e645535a954a ("tracing: Add option to use memmapped memory for trace boot instance")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>
> Acked-by: Catalin Marinas <catalin.marinas@xxxxxxx>

>  arch/m68k/include/asm/Kbuild         |    1 +

Acked-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> # m68k

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds