Re: 2.6.24-rc2 crash in kmap_coherent

[Giuseppe Sacco <giuseppe@eppesuigoccas.homedns.org>]

Hi Ralf,
the change you proposed here give an error since "page" is onlt
available on function copy_user_highpage() while there is not such
variable (nor parameter) in function copy_to_user_page().

I am actually recompiling everything using only the first part of your
patch, but I think it will not be enough.

Bye,
Giuseppe

Il giorno mer, 12/12/2007 alle 15.32 +0000, Ralf Baechle ha scritto:
[...]
> Totally untested because I have other stuff to do but something along the
> lines of below patch, I think.
> 
>   Ralf
> 
> diff --git a/arch/mips/mm/init.c b/arch/mips/mm/init.c
> index 480dec0..db5d608 100644
> --- a/arch/mips/mm/init.c
> +++ b/arch/mips/mm/init.c
> @@ -211,7 +211,8 @@ void copy_user_highpage(struct page *to, struct page *from,
>  	void *vfrom, *vto;
>  
>  	vto = kmap_atomic(to, KM_USER1);
> -	if (cpu_has_dc_aliases && page_mapped(from)) {
> +	if (cpu_has_dc_aliases &&
> +	    page_mapped(from) && !Page_dcache_dirty(from)) {
>  		vfrom = kmap_coherent(from, vaddr);
>  		copy_page(vto, vfrom);
>  		kunmap_coherent();
> @@ -234,7 +235,8 @@ void copy_to_user_page(struct vm_area_struct *vma,
>  	struct page *page, unsigned long vaddr, void *dst, const void *src,
>  	unsigned long len)
>  {
> -	if (cpu_has_dc_aliases && page_mapped(page)) {
> +	if (cpu_has_dc_aliases &&
> +	    page_mapped(page) && !Page_dcache_dirty(from)) {
>  		void *vto = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
>  		memcpy(vto, src, len);
>  		kunmap_coherent();
> @@ -253,7 +255,8 @@ void copy_from_user_page(struct vm_area_struct *vma,
>  	struct page *page, unsigned long vaddr, void *dst, const void *src,
>  	unsigned long len)
>  {
> -	if (cpu_has_dc_aliases && page_mapped(page)) {
> +	if (cpu_has_dc_aliases &&
> +	    page_mapped(page) && !Page_dcache_dirty(page)) {
>  		void *vfrom = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
>  		memcpy(dst, vfrom, len);
>  		kunmap_coherent();
> 
>