Re: [PATCH] kprobes, x86/alternatives: use text_mutex to protect smp_alt_modules

[Borislav Petkov]

On Fri, Oct 27, 2017 at 05:34:44PM +0800, Zhou Chengming wrote:
> Fixes: 2cfa197 "ftrace/alternatives: Introducing *_text_reserved
> functions"
> 
> We use alternatives_text_reserved() to check if the address is in
> the fixed pieces of alternative reserved, but the problem is that
> we don't hold the smp_alt mutex when call this function. So the list
> traversal may encounter a deleted list_head if another path is doing
> alternatives_smp_module_del().

Is this something you've triggered on a real machine or is this just
from code staring?

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Regards/Gruss,
    Boris.

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