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author | Linus Torvalds <torvalds@linux-foundation.org> | 2021-07-04 12:23:05 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-07-04 12:23:05 -0700 |
commit | a412897fb546fbb291095be576165ce757eff70b (patch) | |
tree | ca1e00e721e255d7d6a62862a629697adb22a880 /arch/arm/mm | |
parent | 2bb919b62f6e5959552a90a399d09d683afa3d1d (diff) | |
parent | a4d5613c4dc6d413e0733e37db9d116a2a36b9f3 (diff) | |
download | linux-stable-a412897fb546fbb291095be576165ce757eff70b.tar.gz linux-stable-a412897fb546fbb291095be576165ce757eff70b.tar.bz2 linux-stable-a412897fb546fbb291095be576165ce757eff70b.zip |
Merge tag 'memblock-v5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock
Pull memblock updates from Mike Rapoport:
"Fix arm crashes caused by holes in the memory map.
The coordination between freeing of unused memory map, pfn_valid() and
core mm assumptions about validity of the memory map in various ranges
was not designed for complex layouts of the physical memory with a lot
of holes all over the place.
Kefen Wang reported crashes in move_freepages() on a system with the
following memory layout [1]:
node 0: [mem 0x0000000080a00000-0x00000000855fffff]
node 0: [mem 0x0000000086a00000-0x0000000087dfffff]
node 0: [mem 0x000000008bd00000-0x000000008c4fffff]
node 0: [mem 0x000000008e300000-0x000000008ecfffff]
node 0: [mem 0x0000000090d00000-0x00000000bfffffff]
node 0: [mem 0x00000000cc000000-0x00000000dc9fffff]
node 0: [mem 0x00000000de700000-0x00000000de9fffff]
node 0: [mem 0x00000000e0800000-0x00000000e0bfffff]
node 0: [mem 0x00000000f4b00000-0x00000000f6ffffff]
node 0: [mem 0x00000000fda00000-0x00000000ffffefff]
These crashes can be mitigated by enabling CONFIG_HOLES_IN_ZONE on ARM
and essentially turning pfn_valid_within() to pfn_valid() instead of
having it hardwired to 1 on that architecture, but this would require
to keep CONFIG_HOLES_IN_ZONE solely for this purpose.
A cleaner approach is to update ARM's implementation of pfn_valid() to
take into accounting rounding of the freed memory map to pageblock
boundaries and make sure it returns true for PFNs that have memory map
entries even if there is no physical memory backing those PFNs"
Link: https://lore.kernel.org/lkml/2a1592ad-bc9d-4664-fd19-f7448a37edc0@huawei.com [1]
* tag 'memblock-v5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock:
arm: extend pfn_valid to take into account freed memory map alignment
memblock: ensure there is no overflow in memblock_overlaps_region()
memblock: align freed memory map on pageblock boundaries with SPARSEMEM
memblock: free_unused_memmap: use pageblock units instead of MAX_ORDER
Diffstat (limited to 'arch/arm/mm')
-rw-r--r-- | arch/arm/mm/init.c | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c index 9d4744a632c6..6162a070a410 100644 --- a/arch/arm/mm/init.c +++ b/arch/arm/mm/init.c @@ -125,11 +125,22 @@ static void __init zone_sizes_init(unsigned long min, unsigned long max_low, int pfn_valid(unsigned long pfn) { phys_addr_t addr = __pfn_to_phys(pfn); + unsigned long pageblock_size = PAGE_SIZE * pageblock_nr_pages; if (__phys_to_pfn(addr) != pfn) return 0; - return memblock_is_map_memory(addr); + /* + * If address less than pageblock_size bytes away from a present + * memory chunk there still will be a memory map entry for it + * because we round freed memory map to the pageblock boundaries. + */ + if (memblock_overlaps_region(&memblock.memory, + ALIGN_DOWN(addr, pageblock_size), + pageblock_size)) + return 1; + + return 0; } EXPORT_SYMBOL(pfn_valid); #endif |