Re: [PATCH] kdump: Write a correct address of mem_section into vmcoreinfo

From: Kirill A. Shutemov
Date: Sat Jan 13 2018 - 13:26:35 EST


On Sat, Jan 13, 2018 at 11:48:38AM +0100, Ingo Molnar wrote:
>
> * Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> wrote:
>
> > Depending on configuration mem_section can now be an array or a pointer
> > to an array allocated dynamically. In most cases, we can continue to refer
> > to it as 'mem_section' regardless of what it is.
> >
> > But there's one exception: '&mem_section' means "address of the array" if
> > mem_section is an array, but if mem_section is a pointer, it would mean
> > "address of the pointer".
> >
> > We've stepped onto this in kdump code. VMCOREINFO_SYMBOL(mem_section)
> > writes down address of pointer into vmcoreinfo, not array as we wanted.
> >
> > Let's introduce VMCOREINFO_SYMBOL_ARRAY() that would handle the
> > situation correctly for both cases.
> >
> > Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
> > Fixes: 83e3c48729d9 ("mm/sparsemem: Allocate mem_section at runtime for CONFIG_SPARSEMEM_EXTREME=y")
> > Cc: stable@xxxxxxxxxxxxxxx
> > Acked-by: Baoquan He <bhe@xxxxxxxxxx>
> > Acked-by: Dave Young <dyoung@xxxxxxxxxx>
>
> You forgot the Reported-by - I added that to the commit.

Oops, sorry.

Note, that Andrew has already pick it up and sent it upstream.

--
Kirill A. Shutemov