[PATCH] Before adding to usablemem_rgns, check if the memory range is already included.

[chenhaixiang (A)]

> > When kexec_iomem_for_each_line() reads from /proc/iomem, concurrent
> > modifications to /proc/iomem may lead to usablemem_rgns recording
> > duplicate Crash kernel segments.
> > This can result in the number of retrieved Crash kernel segments
> > exceeding CRASH_MAX_RESERVED_RANGES, triggering a realloc of the
> > crash_reserved_mem in usablemem_rgns, which could crash the process.
> > We should ensure that each range added to usablemem_rgns is unique to
> > prevent these issues.
> 
> Thanks Chen Haixiang,
> 
> This looks reasonable to me, but, as per Kernel submissions, I will need an
> Signed-off-by line [1] in order to apply this patch.
> 
> [1]
> https://www.kernel.org/doc/html/latest/process/submitting-patches.html#sign
> -your-work-the-developer-s-certificate-of-origin

Thank you for your feedback, and I apologize for missing the Signed-off-by line. I'll resend the patch v2 with the required Signed-off-by line shortly.

Best regards,
Chen Haixiang