On 11/05/2015 02:15 AM, Xishi Qiu wrote:
On 2015/11/4 5:48, Laura Abbott wrote:Rather than always putting the least restrictived permissions (PAGE_KERNEL_EXEC) when spliting a pmd into pages, use the existing permissions from the pmd for the page. Signed-off-by: Laura Abbott <labb...@fedoraproject.org> --- arch/arm64/mm/mmu.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index 9211b85..ff41efa 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -75,14 +75,13 @@ static void __init *early_alloc(unsigned long sz) static void split_pmd(pmd_t *pmd, pte_t *pte) { unsigned long pfn = pmd_pfn(*pmd); + unsigned long addr = pfn << PAGE_SHIFT; + pgprot_t prot = __pgprot(pmd_val(*pmd) ^ addr) | PTE_TYPE_PAGE; +Hi Laura, I'm not quite understand, I find split_pud() doesn't set the flag PMD_TYPE_TABLE. If we clear xx_TABLE_BIT, does that means the page is large page?
I'm assuming by large page you mean a block mapping. Yes, without that entry the kernel treats this as a block mapping
And what is the different from the flag xx_TYPE_SECT?
That would mark it this as a block mapping which is not what we want here.
Thanks, Xishi Qiu
-- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
