diff options
Diffstat (limited to 'mm/highmem.c')
| -rw-r--r-- | mm/highmem.c | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/mm/highmem.c b/mm/highmem.c index fab128de97de..39aaca1a1ece 100644 --- a/mm/highmem.c +++ b/mm/highmem.c @@ -474,7 +474,12 @@ void *__kmap_local_page_prot(struct page *page, pgprot_t prot) { void *kmap; - if (!PageHighMem(page)) + /* + * To broaden the usage of the actual kmap_local() machinery always map + * pages when debugging is enabled and the architecture has no problems + * with alias mappings. + */ + if (!IS_ENABLED(CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP) && !PageHighMem(page)) return page_address(page); /* Try kmap_high_get() if architecture has it enabled */ @@ -494,6 +499,11 @@ void kunmap_local_indexed(void *vaddr) if (addr < __fix_to_virt(FIX_KMAP_END) || addr > __fix_to_virt(FIX_KMAP_BEGIN)) { + if (IS_ENABLED(CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP)) { + /* This _should_ never happen! See above. */ + WARN_ON_ONCE(1); + return; + } /* * Handle mappings which were obtained by kmap_high_get() * first as the virtual address of such mappings is below |