Messages in this thread | | | Date | Wed, 24 Feb 2016 09:02:46 +0100 | From | Lars Persson <> | Subject | Re: [PATCH 2/2] MIPS: Flush highmem pages from dcache in __flush_icache_page |
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On 02/22/2016 07:09 PM, Paul Burton wrote: > When a page is to be mapped executable for userspace, we can presume > that the icache doesn't contain anything valid for its address range but > we cannot be sure that its content has been written back from the dcache > to L2 or memory further out. If the icache fills from those memories, > ie. does not fill from the dcache, then we need to ensure that content > has been flushed from the dcache. This was being done for lowmem pages > but not for highmem pages. Fix this by mapping the page & flushing its > content from the dcache in __flush_icache_page, before the page is > provided to userland. >
Reviewed-by: Lars Persson <larper@axis.com>
> Signed-off-by: Paul Burton <paul.burton@imgtec.com> > > --- > > arch/mips/mm/cache.c | 9 +++++++-- > 1 file changed, 7 insertions(+), 2 deletions(-) > > diff --git a/arch/mips/mm/cache.c b/arch/mips/mm/cache.c > index 3f159ca..734cb2f 100644 > --- a/arch/mips/mm/cache.c > +++ b/arch/mips/mm/cache.c > @@ -16,6 +16,7 @@ > #include <linux/mm.h> > > #include <asm/cacheflush.h> > +#include <asm/highmem.h> > #include <asm/processor.h> > #include <asm/cpu.h> > #include <asm/cpu-features.h> > @@ -124,10 +125,14 @@ void __flush_icache_page(struct vm_area_struct *vma, struct page *page) > unsigned long addr; > > if (PageHighMem(page)) > - return; > + addr = (unsigned long)kmap_atomic(page); > + else > + addr = (unsigned long)page_address(page); > > - addr = (unsigned long) page_address(page); > flush_data_cache_page(addr); > + > + if (PageHighMem(page)) > + __kunmap_atomic((void *)addr); > } > EXPORT_SYMBOL_GPL(__flush_icache_page); > >
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