[PATCH 1/4] kexec-tools: mips: Merge adjacent memory ranges.

[Simon Horman]

On Mon, Oct 16, 2017 at 09:13:30AM -0700, David Daney wrote:
> On 10/15/2017 11:53 PM, Simon Horman wrote:
> > On Thu, Oct 12, 2017 at 02:02:25PM -0700, David Daney wrote:
> > > Some kernel versions running on MIPS split the System RAM memory
> > > regions reported in /proc/iomem.  This may cause loading of the kexec
> > > kernel to fail if it crosses one of the splits.
> > > 
> > > Fix by merging adjacent memory ranges that have the same type.
> > > 
> > > Signed-off-by: David Daney <david.daney at cavium.com>
> > > ---
> > >   kexec/arch/mips/kexec-mips.c | 14 ++++++++++----
> > >   1 file changed, 10 insertions(+), 4 deletions(-)
> > > 
> > > diff --git a/kexec/arch/mips/kexec-mips.c b/kexec/arch/mips/kexec-mips.c
> > > index 2e5b700..415c2ed 100644
> > > --- a/kexec/arch/mips/kexec-mips.c
> > > +++ b/kexec/arch/mips/kexec-mips.c
> > > @@ -60,10 +60,16 @@ int get_memory_ranges(struct memory_range **range, int *ranges,
> > >   		} else {
> > >   			continue;
> > >   		}
> > > -		memory_range[memory_ranges].start = start;
> > > -		memory_range[memory_ranges].end = end;
> > > -		memory_range[memory_ranges].type = type;
> > > -		memory_ranges++;
> > > +		if (memory_ranges > 0 &&
> > 
> > It seems that this will never merge the first memory range
> > with subsequent ones. Is that intentional?
> 
> 
> With the first range (index 0), no other range yet exists to merge with.  We
> can only test for merging with the second and subsequent ranges (indices 1
> and above).  To do otherwise would cause us to read things from *before* the
> beginning of the array ...

Yes, of course. I see that now.

I've applied this patch.

> > 
> > 
> > > +		    memory_range[memory_ranges - 1].end == start &&
> 
> ... here.
> 
> > > +		    memory_range[memory_ranges - 1].type == type) {
> > > +			memory_range[memory_ranges - 1].end = end;
> > > +		} else {
> > > +			memory_range[memory_ranges].start = start;
> > > +			memory_range[memory_ranges].end = end;
> > > +			memory_range[memory_ranges].type = type;
> > > +			memory_ranges++;
> > > +		}
> > >   	}
> > >   	fclose(fp);
> > >   	*range = memory_range;
> > > -- 
> > > 2.9.5
> > > 
> > > 
> > > _______________________________________________
> > > kexec mailing list
> > > kexec at lists.infradead.org
> > > http://lists.infradead.org/mailman/listinfo/kexec
> > > 
> 
> 
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