On Tue, 1 Oct 2019 11:49:47 +0200 David Hildenbrand <[email protected]> wrote:
> > @@ -278,6 +278,22 @@ static int check_pfn_span(unsigned long pfn, unsigned
> > long nr_pages,
> > return 0;
> > }
> >
> > +static int check_hotplug_memory_addressable(unsigned long pfn,
> > + unsigned long nr_pages)
> > +{
> > + const u64 max_addr = PFN_PHYS(pfn + nr_pages) - 1;
> > +
> > + if (max_addr >> MAX_PHYSMEM_BITS) {
> > + const u64 max_allowed = (1ull << (MAX_PHYSMEM_BITS + 1)) - 1;
> > + WARN(1,
> > + "Hotplugged memory exceeds maximum addressable address,
> > range=%#llx-%#llx, maximum=%#llx\n",
> > + (u64)PFN_PHYS(pfn), max_addr, max_allowed);
> > + return -E2BIG;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > /*
> > * Reasonably generic function for adding memory. It is
> > * expected that archs that support memory hotplug will
> > @@ -291,6 +307,10 @@ int __ref __add_pages(int nid, unsigned long pfn,
> > unsigned long nr_pages,
> > unsigned long nr, start_sec, end_sec;
> > struct vmem_altmap *altmap = restrictions->altmap;
> >
> > + err = check_hotplug_memory_addressable(pfn, nr_pages);
> > + if (err)
> > + return err;
> > +
> > if (altmap) {
> > /*
> > * Validate altmap is within bounds of the total request
> >
>
> I actually wanted to give my RB to v7, not v6 :)
>
Given that check_hotplug_memory_addressable() is now static, I'll
assume that the old [2/2]
mm-add-a-bounds-check-in-devm_memremap_pages.patch is now obsolete.
From: Alastair D'Silva <[email protected]>
Subject: mm/memremap.c: add a bounds check in devm_memremap_pages()
The call to check_hotplug_memory_addressable() validates that the memory
is fully addressable.
Without this call, it is possible that we may remap pages that is not
physically addressable, resulting in bogus section numbers being returned
from __section_nr().
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Alastair D'Silva <[email protected]>
Acked-by: David Hildenbrand <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: Ira Weiny <[email protected]>
Cc: Jason Gunthorpe <[email protected]>
Cc: Logan Gunthorpe <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Oscar Salvador <[email protected]>
Cc: Pavel Tatashin <[email protected]>
Cc: Qian Cai <[email protected]>
Cc: Wei Yang <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
---
mm/memremap.c | 5 +++++
1 file changed, 5 insertions(+)
--- a/mm/memremap.c~mm-add-a-bounds-check-in-devm_memremap_pages
+++ a/mm/memremap.c
@@ -185,6 +185,11 @@ void *memremap_pages(struct dev_pagemap
int error, is_ram;
bool need_devmap_managed = true;
+ error = check_hotplug_memory_addressable(res->start,
+ resource_size(res));
+ if (error)
+ return ERR_PTR(error);
+
switch (pgmap->type) {
case MEMORY_DEVICE_PRIVATE:
if (!IS_ENABLED(CONFIG_DEVICE_PRIVATE)) {
_
