On Fri, Apr 27, 2018 at 05:15:26PM -0700, Luis R. Rodriguez wrote: > Some architectures do not define PAGE_KERNEL_RO, best we can do > for them is to provide a fallback onto PAGE_KERNEL. Remove the > hack from the firmware loader and move it onto the asm-generic > header, and document while at it the affected architectures > which do not have a PAGE_KERNEL_RO: > > o alpha > o ia64 > o m68k > o mips > o sparc64 > o sparc ia64 doesn't have it? *fx: riffles through architecture book* That seems like an oversight of the Linux port. Tony, Fenghua, any thoughts? (also, Luis, maybe move the PAGE_KERNEL_EXEC fallback the same way you moved the PAGE_KERNEL_RO fallback?) --- >8 --- ia64: Add PAGE_KERNEL_RO and PAGE_KERNEL_EXEC The rest of the kernel was falling back to simple PAGE_KERNEL pages; using PAGE_KERNEL_RO and PAGE_KERNEL_EXEC provide better protection against unintended writes. Signed-off-by: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx> diff --git a/arch/ia64/include/asm/pgtable.h b/arch/ia64/include/asm/pgtable.h index 165827774bea..041a32a7960d 100644 --- a/arch/ia64/include/asm/pgtable.h +++ b/arch/ia64/include/asm/pgtable.h @@ -23,7 +23,7 @@ /* * First, define the various bits in a PTE. Note that the PTE format - * matches the VHPT short format, the firt doubleword of the VHPD long + * matches the VHPT short format, the first doubleword of the VHPD long * format, and the first doubleword of the TLB insertion format. */ #define _PAGE_P_BIT 0 @@ -142,9 +142,11 @@ #define PAGE_COPY_EXEC __pgprot(__ACCESS_BITS | _PAGE_PL_3 | _PAGE_AR_RX) #define PAGE_GATE __pgprot(__ACCESS_BITS | _PAGE_PL_0 | _PAGE_AR_X_RX) #define PAGE_KERNEL __pgprot(__DIRTY_BITS | _PAGE_PL_0 | _PAGE_AR_RWX) -#define PAGE_KERNELRX __pgprot(__ACCESS_BITS | _PAGE_PL_0 | _PAGE_AR_RX) +#define PAGE_KERNEL_RO __pgprot(__ACCESS_BITS | _PAGE_PL_0 | _PAGE_AR_R) +#define PAGE_KERNEL_RX __pgprot(__ACCESS_BITS | _PAGE_PL_0 | _PAGE_AR_RX) #define PAGE_KERNEL_UC __pgprot(__DIRTY_BITS | _PAGE_PL_0 | _PAGE_AR_RWX | \ _PAGE_MA_UC) +#define PAGE_KERNEL_EXEC PAGE_KERNEL_RX # ifndef __ASSEMBLY__
