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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: Vineet Gupta <vgupta@synopsys.com>
This commit is contained in:
Vineet Gupta 2013-05-25 14:04:25 +05:30
parent 006dfb3c9c
commit 7bb66f6e6e
2 changed files with 11 additions and 19 deletions
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9
arch/arc/include/asm/page.h
View File

@ -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

21
arch/arc/mm/cache_arc700.c
View File

@ -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