diff options
Diffstat (limited to 'include/linux/mmzone.h')
| -rw-r--r-- | include/linux/mmzone.h | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 7da43337ad23..7bc7e41b6c31 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -1460,6 +1460,15 @@ static inline int pfn_valid(unsigned long pfn) { struct mem_section *ms; + /* + * Ensure the upper PAGE_SHIFT bits are clear in the + * pfn. Else it might lead to false positives when + * some of the upper bits are set, but the lower bits + * match a valid pfn. + */ + if (PHYS_PFN(PFN_PHYS(pfn)) != pfn) + return 0; + if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS) return 0; ms = __nr_to_section(pfn_to_section_nr(pfn)); |