diff options
Diffstat (limited to 'target/linux/generic/patches-4.3/101-MIPS-fix-cache-flushing-for-highmem-pages.patch')
-rw-r--r-- | target/linux/generic/patches-4.3/101-MIPS-fix-cache-flushing-for-highmem-pages.patch | 101 |
1 files changed, 0 insertions, 101 deletions
diff --git a/target/linux/generic/patches-4.3/101-MIPS-fix-cache-flushing-for-highmem-pages.patch b/target/linux/generic/patches-4.3/101-MIPS-fix-cache-flushing-for-highmem-pages.patch deleted file mode 100644 index 6a6c581bc5..0000000000 --- a/target/linux/generic/patches-4.3/101-MIPS-fix-cache-flushing-for-highmem-pages.patch +++ /dev/null @@ -1,101 +0,0 @@ -From: Felix Fietkau <nbd@openwrt.org> -Date: Sun, 24 Jan 2016 01:03:51 +0100 -Subject: [PATCH] MIPS: fix cache flushing for highmem pages - -Most cache flush ops were no-op for highmem pages. This led to nasty -segfaults and (in the case of page_address(page) == NULL) kernel -crashes. - -Fix this by always flushing highmem pages using kmap/kunmap_atomic -around the actual cache flush. This might be a bit inefficient, but at -least it's stable. - -Signed-off-by: Felix Fietkau <nbd@openwrt.org> ---- - ---- a/arch/mips/mm/cache.c -+++ b/arch/mips/mm/cache.c -@@ -14,6 +14,7 @@ - #include <linux/sched.h> - #include <linux/syscalls.h> - #include <linux/mm.h> -+#include <linux/highmem.h> - - #include <asm/cacheflush.h> - #include <asm/processor.h> -@@ -78,18 +79,29 @@ SYSCALL_DEFINE3(cacheflush, unsigned lon - return 0; - } - -+static void -+flush_highmem_page(struct page *page) -+{ -+ void *addr = kmap_atomic(page); -+ flush_data_cache_page((unsigned long)addr); -+ kunmap_atomic(addr); -+} -+ - void __flush_dcache_page(struct page *page) - { - struct address_space *mapping = page_mapping(page); - unsigned long addr; - -- if (PageHighMem(page)) -- return; - if (mapping && !mapping_mapped(mapping)) { - SetPageDcacheDirty(page); - return; - } - -+ if (PageHighMem(page)) { -+ flush_highmem_page(page); -+ return; -+ } -+ - /* - * We could delay the flush for the !page_mapping case too. But that - * case is for exec env/arg pages and those are %99 certainly going to -@@ -105,6 +117,11 @@ void __flush_anon_page(struct page *page - { - unsigned long addr = (unsigned long) page_address(page); - -+ if (PageHighMem(page)) { -+ flush_highmem_page(page); -+ return; -+ } -+ - if (pages_do_alias(addr, vmaddr)) { - if (page_mapped(page) && !Page_dcache_dirty(page)) { - void *kaddr; -@@ -123,8 +140,10 @@ void __flush_icache_page(struct vm_area_ - { - unsigned long addr; - -- if (PageHighMem(page)) -+ if (PageHighMem(page)) { -+ flush_highmem_page(page); - return; -+ } - - addr = (unsigned long) page_address(page); - flush_data_cache_page(addr); -@@ -142,12 +161,17 @@ void __update_cache(struct vm_area_struc - if (unlikely(!pfn_valid(pfn))) - return; - page = pfn_to_page(pfn); -- if (page_mapping(page) && Page_dcache_dirty(page)) { -+ if (!Page_dcache_dirty(page) || !page_mapping(page)) -+ return; -+ -+ if (PageHighMem(page)) { -+ flush_highmem_page(page); -+ } else { - addr = (unsigned long) page_address(page); - if (exec || pages_do_alias(addr, address & PAGE_MASK)) - flush_data_cache_page(addr); -- ClearPageDcacheDirty(page); - } -+ ClearPageDcacheDirty(page); - } - - unsigned long _page_cachable_default; |