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-rw-r--r--target/linux/generic/patches-4.3/101-MIPS-fix-cache-flushing-for-highmem-pages.patch101
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;