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Commit 7bb66f6e authored by Vineet Gupta's avatar Vineet Gupta
Browse files

ARC: lazy dcache flush broke gdb in non-aliasing configs 



gdbserver inserting a breakpoint ends up calling copy_user_page() for a
code page. The generic version of which (non-aliasing config) didn't set
the PG_arch_1 bit hence update_mmu_cache() didn't sync dcache/icache for
corresponding dynamic loader code page - causing garbade to be executed.

So now aliasing versions of copy_user_highpage()/clear_page() are made
default. There is no significant overhead since all of special alias
handling code is compiled out for non-aliasing build

Signed-off-by: default avatarVineet Gupta <vgupta@synopsys.com>
parent 006dfb3c

arch/arc/include/asm/page.h

+0 −9
Original line number Diff line number Diff line
@@ -19,13 +19,6 @@ 
#define clear_page(paddr)		memset((paddr), 0, PAGE_SIZE)

#define copy_page(to, from)		memcpy((to), (from), PAGE_SIZE)



#ifndef CONFIG_ARC_CACHE_VIPT_ALIASING



#define clear_user_page(addr, vaddr, pg)	clear_page(addr)

#define copy_user_page(vto, vfrom, vaddr, pg)	copy_page(vto, vfrom)



#else	/* VIPT aliasing dcache */



struct vm_area_struct;

struct page;
@@ -35,8 +28,6 @@ void copy_user_highpage(struct page *to, struct page *from, 
			unsigned long u_vaddr, struct vm_area_struct *vma);

void clear_user_page(void *to, unsigned long u_vaddr, struct page *page);



#endif	/* CONFIG_ARC_CACHE_VIPT_ALIASING */



#undef STRICT_MM_TYPECHECKS



#ifdef STRICT_MM_TYPECHECKS

arch/arc/mm/cache_arc700.c

+11 −10
Original line number Diff line number Diff line
@@ -676,6 +676,17 @@ void flush_cache_range(struct vm_area_struct *vma, unsigned long start, 
	flush_cache_all();

}



void flush_anon_page(struct vm_area_struct *vma, struct page *page,

		     unsigned long u_vaddr)

{

	/* TBD: do we really need to clear the kernel mapping */

	__flush_dcache_page(page_address(page), u_vaddr);

	__flush_dcache_page(page_address(page), page_address(page));



}



#endif



void copy_user_highpage(struct page *to, struct page *from,

	unsigned long u_vaddr, struct vm_area_struct *vma)

{
@@ -725,16 +736,6 @@ void clear_user_page(void *to, unsigned long u_vaddr, struct page *page) 
	set_bit(PG_arch_1, &page->flags);

}



void flush_anon_page(struct vm_area_struct *vma, struct page *page,

		     unsigned long u_vaddr)

{

	/* TBD: do we really need to clear the kernel mapping */

	__flush_dcache_page(page_address(page), u_vaddr);

	__flush_dcache_page(page_address(page), page_address(page));



}



#endif



/**********************************************************************

 * Explicit Cache flush request from user space via syscall