diff options
| -rw-r--r-- | mm/highmem.c | 19 |
1 files changed, 13 insertions, 6 deletions
diff --git a/mm/highmem.c b/mm/highmem.c index 54bd233846c9..78c481a30c9a 100644 --- a/mm/highmem.c +++ b/mm/highmem.c @@ -426,12 +426,15 @@ static inline void *arch_kmap_local_high_get(struct page *page) #endif /* Unmap a local mapping which was obtained by kmap_high_get() */ -static inline void kmap_high_unmap_local(unsigned long vaddr) +static inline bool kmap_high_unmap_local(unsigned long vaddr) { #ifdef ARCH_NEEDS_KMAP_HIGH_GET - if (vaddr >= PKMAP_ADDR(0) && vaddr < PKMAP_ADDR(LAST_PKMAP)) + if (vaddr >= PKMAP_ADDR(0) && vaddr < PKMAP_ADDR(LAST_PKMAP)) { kunmap_high(pte_page(pkmap_page_table[PKMAP_NR(vaddr)])); + return true; + } #endif + return false; } static inline int kmap_local_calc_idx(int idx) @@ -491,10 +494,14 @@ void kunmap_local_indexed(void *vaddr) if (addr < __fix_to_virt(FIX_KMAP_END) || addr > __fix_to_virt(FIX_KMAP_BEGIN)) { - WARN_ON_ONCE(addr < PAGE_OFFSET); - - /* Handle mappings which were obtained by kmap_high_get() */ - kmap_high_unmap_local(addr); + /* + * Handle mappings which were obtained by kmap_high_get() + * first as the virtual address of such mappings is below + * PAGE_OFFSET. Warn for all other addresses which are in + * the user space part of the virtual address space. + */ + if (!kmap_high_unmap_local(addr)) + WARN_ON_ONCE(addr < PAGE_OFFSET); return; } |