| Message ID | 1392396913-13570-3-git-send-email-steve.capper@linaro.org |
|---|---|
| State | New |
| Headers | show |
On Thu, Feb 20, 2014 at 05:26:51PM +0000, Will Deacon wrote: > On Fri, Feb 14, 2014 at 04:55:13PM +0000, Steve Capper wrote: > > On LPAE, L_PTE_WRITE and L_PTE_DIRTY are in the upper 32-bits. > > Unfortunately, results from pte_write() and pte_dirty() are downcast > > to 32-bits by core code: > > o gather_stats > > o huge_pte_dirty > > o huge_pte_write > > o make_migration_entry > > > > This patch adds a double logical invert to pte_write() and pte_dirty() > > for LPAE to ensure that the lower 32-bits are set if true. > > Yikes, this sounds like something we should put in -stable, no? If so, > better make it patch 1 of this series. Yeah, it makes sense to have this as the first patch. It probably should go through stable, I will mark the next version of this patch for stable. > > Reviewed-by: Will Deacon <will.deacon@arm.com> Thanks Will. Cheers, -- Steve
On Thu, Feb 20, 2014 at 05:26:51PM +0000, Will Deacon wrote: > On Fri, Feb 14, 2014 at 04:55:13PM +0000, Steve Capper wrote: > > On LPAE, L_PTE_WRITE and L_PTE_DIRTY are in the upper 32-bits. > > Unfortunately, results from pte_write() and pte_dirty() are downcast > > to 32-bits by core code: > > o gather_stats > > o huge_pte_dirty > > o huge_pte_write > > o make_migration_entry > > > > This patch adds a double logical invert to pte_write() and pte_dirty() > > for LPAE to ensure that the lower 32-bits are set if true. > > Yikes, this sounds like something we should put in -stable, no? If so, > better make it patch 1 of this series. That's a bug on arm64 as well since functions like gather_stats() take an int as argument. However, my preference is for a static inline function instead of "!!" on arm64. Steve, would you send a patch for arm64? If not, I can do it (with your reported-by). Thanks.
On Fri, Feb 21, 2014 at 11:28:12AM +0000, Russell King - ARM Linux wrote: > On Fri, Feb 14, 2014 at 04:55:13PM +0000, Steve Capper wrote: > > On LPAE, L_PTE_WRITE and L_PTE_DIRTY are in the upper 32-bits. > > Unfortunately, results from pte_write() and pte_dirty() are downcast > > to 32-bits by core code: > > o gather_stats > > o huge_pte_dirty > > o huge_pte_write > > o make_migration_entry > > > > This patch adds a double logical invert to pte_write() and pte_dirty() > > for LPAE to ensure that the lower 32-bits are set if true. > > We should ensure all those functions return something which is compatible > with "int" correctly. It didn't matter for non-LPAE as the PTEs fit in > 32-bit, but with LPAE, that really needs fixing independently of your > other patch. Agreed, I'm getting that written/tested now for arm and arm64. Cheers,
diff --git a/arch/arm/include/asm/pgtable-2level.h b/arch/arm/include/asm/pgtable-2level.h index ca43b84..7e8ebe7 100644 --- a/arch/arm/include/asm/pgtable-2level.h +++ b/arch/arm/include/asm/pgtable-2level.h @@ -162,6 +162,8 @@ static inline pmd_t *pmd_offset(pud_t *pud, unsigned long addr) #define pmd_large(pmd) (pmd_val(pmd) & 2) #define pmd_bad(pmd) (pmd_val(pmd) & 2) +#define pte_write(pte) (pte_val(pte) & L_PTE_WRITE) +#define pte_dirty(pte) (pte_val(pte) & L_PTE_DIRTY) #define copy_pmd(pmdpd,pmdps) \ do { \ diff --git a/arch/arm/include/asm/pgtable-3level.h b/arch/arm/include/asm/pgtable-3level.h index 8a392ef..62efcc5 100644 --- a/arch/arm/include/asm/pgtable-3level.h +++ b/arch/arm/include/asm/pgtable-3level.h @@ -135,6 +135,20 @@ #ifndef __ASSEMBLY__ +/* + * On LPAE, L_PTE_WRITE and L_PTE_DIRTY are in the upper 32-bits. + * Unfortunately, results from pte_write() and pte_dirty() are downcast + * to 32-bits by core code: + * o gather_stats + * o huge_pte_dirty + * o huge_pte_write + * o make_migration_entry + * + * Double logical invert to make sure lower 32-bits are set if true. + */ +#define pte_write(pte) (!!(pte_val(pte) & L_PTE_WRITE)) +#define pte_dirty(pte) (!!(pte_val(pte) & L_PTE_DIRTY)) + #define pud_none(pud) (!pud_val(pud)) #define pud_bad(pud) (!(pud_val(pud) & 2)) #define pud_present(pud) (pud_val(pud)) diff --git a/arch/arm/include/asm/pgtable.h b/arch/arm/include/asm/pgtable.h index 7a17611..e94a616 100644 --- a/arch/arm/include/asm/pgtable.h +++ b/arch/arm/include/asm/pgtable.h @@ -216,8 +216,6 @@ static inline pte_t *pmd_page_vaddr(pmd_t pmd) #define pte_none(pte) (!pte_val(pte)) #define pte_present(pte) (pte_val(pte) & L_PTE_PRESENT) -#define pte_write(pte) (pte_val(pte) & L_PTE_WRITE) -#define pte_dirty(pte) (pte_val(pte) & L_PTE_DIRTY) #define pte_young(pte) (pte_val(pte) & L_PTE_YOUNG) #define pte_exec(pte) (!(pte_val(pte) & L_PTE_XN)) #define pte_special(pte) (0)
On LPAE, L_PTE_WRITE and L_PTE_DIRTY are in the upper 32-bits. Unfortunately, results from pte_write() and pte_dirty() are downcast to 32-bits by core code: o gather_stats o huge_pte_dirty o huge_pte_write o make_migration_entry This patch adds a double logical invert to pte_write() and pte_dirty() for LPAE to ensure that the lower 32-bits are set if true. Signed-off-by: Steve Capper <steve.capper@linaro.org> --- arch/arm/include/asm/pgtable-2level.h | 2 ++ arch/arm/include/asm/pgtable-3level.h | 14 ++++++++++++++ arch/arm/include/asm/pgtable.h | 2 -- 3 files changed, 16 insertions(+), 2 deletions(-)