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Commit 1c9d3df5 authored by Richard Purdie's avatar Richard Purdie Committed by Russell King
Browse files

[ARM] 4078/1: Fix ARM copypage cache coherency problems 



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 for 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: default avatarRichard Purdie <rpurdie@rpsys.net>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent b0b1d60a

arch/arm/mm/copypage-v4mc.c

+6 −0
Original line number Diff line number Diff line
@@ -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);

arch/arm/mm/copypage-v6.c

+4 −0
Original line number Diff line number Diff line
@@ -53,6 +53,10 @@ static void v6_copy_user_page_aliasing(void *kto, const void *kfrom, unsigned lo 
{

	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.

arch/arm/mm/copypage-xscale.c

+6 −0
Original line number Diff line number Diff line
@@ -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);

include/asm-arm/cacheflush.h

+2 −0
Original line number Diff line number Diff line
@@ -355,6 +355,8 @@ extern void flush_ptrace_access(struct vm_area_struct *vma, struct page *page, 
 */

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) \