If PG_dcache_dirty is set for a page, we need to flush the source page
before performing any copypage operation using a different virtual address.
This fixes the copypage implementations on XScale, StrongARM and ARMv6.
This patch fixes segmentation faults seen in the dynamic linker under
the usage patterns in glibc 2.4/2.5.
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
---
arch/arm/mm/copypage-v4mc.c | 6 ++++++
arch/arm/mm/copypage-v6.c | 4 ++++
arch/arm/mm/copypage-xscale.c | 6 ++++++
include/asm-arm/cacheflush.h | 2 ++
4 files changed, 18 insertions(+)
Index: git/arch/arm/mm/copypage-xscale.c
===================================================================
--- git.orig/arch/arm/mm/copypage-xscale.c 2006-12-30 15:04:19.000000000 +0000
+++ git/arch/arm/mm/copypage-xscale.c 2006-12-30 15:04:22.000000000 +0000
@@ -19,6 +19,7 @@
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/tlbflush.h>
+#include <asm/cacheflush.h>
#include "mm.h"
@@ -91,6 +92,11 @@ mc_copy_user_page(void *from, void *to)
void xscale_mc_copy_user_page(void *kto, const void *kfrom, unsigned long vaddr)
{
+ struct page *page = virt_to_page(kfrom);
+
+ if (test_and_clear_bit(PG_dcache_dirty, &page->flags))
+ __flush_dcache_page(page_mapping(page), page);
+
spin_lock(&minicache_lock);
set_pte_ext(TOP_PTE(COPYPAGE_MINICACHE), pfn_pte(__pa(kfrom) >> PAGE_SHIFT, minicache_pgprot), 0);
Index: git/arch/arm/mm/copypage-v4mc.c
===================================================================
--- git.orig/arch/arm/mm/copypage-v4mc.c 2006-12-30 15:04:19.000000000 +0000
+++ git/arch/arm/mm/copypage-v4mc.c 2006-12-30 15:04:22.000000000 +0000
@@ -19,6 +19,7 @@
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/tlbflush.h>
+#include <asm/cacheflush.h>
#include "mm.h"
@@ -69,6 +70,11 @@ mc_copy_user_page(void *from, void *to)
void v4_mc_copy_user_page(void *kto, const void *kfrom, unsigned long vaddr)
{
+ struct page *page = virt_to_page(kfrom);
+
+ if (test_and_clear_bit(PG_dcache_dirty, &page->flags))
+ __flush_dcache_page(page_mapping(page), page);
+
spin_lock(&minicache_lock);
set_pte_ext(TOP_PTE(0xffff8000), pfn_pte(__pa(kfrom) >> PAGE_SHIFT, minicache_pgprot), 0);
Index: git/arch/arm/mm/copypage-v6.c
===================================================================
--- git.orig/arch/arm/mm/copypage-v6.c 2006-12-30 15:04:19.000000000 +0000
+++ git/arch/arm/mm/copypage-v6.c 2006-12-30 15:04:22.000000000 +0000
@@ -53,6 +53,10 @@ static void v6_copy_user_page_aliasing(v
{
unsigned int offset = CACHE_COLOUR(vaddr);
unsigned long from, to;
+ struct page *page = virt_to_page(kfrom);
+
+ if (test_and_clear_bit(PG_dcache_dirty, &page->flags))
+ __flush_dcache_page(page_mapping(page), page);
/*
* Discard data in the kernel mapping for the new page.
Index: git/include/asm-arm/cacheflush.h
===================================================================
--- git.orig/include/asm-arm/cacheflush.h 2006-12-30 15:04:19.000000000 +0000
+++ git/include/asm-arm/cacheflush.h 2006-12-30 15:04:22.000000000 +0000
@@ -355,6 +355,8 @@ extern void flush_ptrace_access(struct v
*/
extern void flush_dcache_page(struct page *);
+extern void __flush_dcache_page(struct address_space *mapping, struct page *page);
+
#define flush_dcache_mmap_lock(mapping) \
write_lock_irq(&(mapping)->tree_lock)
#define flush_dcache_mmap_unlock(mapping) \