mirror of
https://github.com/openwrt/openwrt.git
synced 2024-12-27 01:11:14 +00:00
32 lines
930 B
Diff
32 lines
930 B
Diff
From: Felix Fietkau <nbd@nbd.name>
|
|
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@nbd.name>
|
|
---
|
|
|
|
--- a/arch/mips/mm/cache.c
|
|
+++ b/arch/mips/mm/cache.c
|
|
@@ -111,6 +111,13 @@ void __flush_anon_page(struct page *page
|
|
{
|
|
unsigned long addr = (unsigned long) page_address(page);
|
|
|
|
+ if (PageHighMem(page)) {
|
|
+ addr = (unsigned long)kmap_atomic(page);
|
|
+ flush_data_cache_page(addr);
|
|
+ __kunmap_atomic((void *)addr);
|
|
+ return;
|
|
+ }
|
|
+
|
|
if (pages_do_alias(addr, vmaddr)) {
|
|
if (page_mapped(page) && !Page_dcache_dirty(page)) {
|
|
void *kaddr;
|