| Message ID | 1366683430-24328-1-git-send-email-cdall@cs.columbia.edu (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, 22 Apr 2013 19:17:10 -0700, Christoffer Dall <cdall@cs.columbia.edu> wrote: > THe L_PTE_USER actually has nothing to do with stage 2 mappings and the > L_PTE_S2_RDONLY value sets the readable bit, which was what L_PTE_USER > was used for before proper handling of stage 2 memory defines. > > Signed-off-by: Christoffer Dall <cdall@cs.columbia.edu> > --- > arch/arm/include/asm/pgtable.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/arm/include/asm/pgtable.h > b/arch/arm/include/asm/pgtable.h > index 80d6fc4..1d1f97f 100644 > --- a/arch/arm/include/asm/pgtable.h > +++ b/arch/arm/include/asm/pgtable.h > @@ -88,7 +88,7 @@ extern pgprot_t pgprot_s2_device; > #define PAGE_HYP _MOD_PROT(pgprot_kernel, L_PTE_HYP) > #define PAGE_HYP_DEVICE _MOD_PROT(pgprot_hyp_device, L_PTE_HYP) > #define PAGE_S2 _MOD_PROT(pgprot_s2, L_PTE_S2_RDONLY) > -#define PAGE_S2_DEVICE _MOD_PROT(pgprot_s2_device, L_PTE_USER | > L_PTE_S2_RDONLY) > +#define PAGE_S2_DEVICE _MOD_PROT(pgprot_s2_device, L_PTE_S2_RDONLY) > > #define __PAGE_NONE __pgprot(_L_PTE_DEFAULT | L_PTE_RDONLY | L_PTE_XN | > L_PTE_NONE) > #define __PAGE_SHARED __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_XN) Good catch. While we're at it, why not directly set it to be RW instead of RO? The only use of PAGE_S2_DEVICE immediately sets the writeable bit anyway. M.
On Tue, Apr 23, 2013 at 12:45 AM, Marc Zyngier <marc.zyngier@arm.com> wrote: > On Mon, 22 Apr 2013 19:17:10 -0700, Christoffer Dall > <cdall@cs.columbia.edu> wrote: >> THe L_PTE_USER actually has nothing to do with stage 2 mappings and the >> L_PTE_S2_RDONLY value sets the readable bit, which was what L_PTE_USER >> was used for before proper handling of stage 2 memory defines. >> >> Signed-off-by: Christoffer Dall <cdall@cs.columbia.edu> >> --- >> arch/arm/include/asm/pgtable.h | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/arch/arm/include/asm/pgtable.h >> b/arch/arm/include/asm/pgtable.h >> index 80d6fc4..1d1f97f 100644 >> --- a/arch/arm/include/asm/pgtable.h >> +++ b/arch/arm/include/asm/pgtable.h >> @@ -88,7 +88,7 @@ extern pgprot_t pgprot_s2_device; >> #define PAGE_HYP _MOD_PROT(pgprot_kernel, L_PTE_HYP) >> #define PAGE_HYP_DEVICE _MOD_PROT(pgprot_hyp_device, L_PTE_HYP) >> #define PAGE_S2 _MOD_PROT(pgprot_s2, L_PTE_S2_RDONLY) >> -#define PAGE_S2_DEVICE _MOD_PROT(pgprot_s2_device, L_PTE_USER | >> L_PTE_S2_RDONLY) >> +#define PAGE_S2_DEVICE _MOD_PROT(pgprot_s2_device, L_PTE_S2_RDONLY) >> >> #define __PAGE_NONE __pgprot(_L_PTE_DEFAULT | L_PTE_RDONLY | L_PTE_XN > | >> L_PTE_NONE) >> #define __PAGE_SHARED __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_XN) > > Good catch. > > While we're at it, why not directly set it to be RW instead of RO? The > only use of PAGE_S2_DEVICE immediately sets the writeable bit anyway. > hmm, any potential future uses of read-only device mappings? It seems "easier" to or on write permissions than remove them, or maybe I'm imagining things...
diff --git a/arch/arm/include/asm/pgtable.h b/arch/arm/include/asm/pgtable.h index 80d6fc4..1d1f97f 100644 --- a/arch/arm/include/asm/pgtable.h +++ b/arch/arm/include/asm/pgtable.h @@ -88,7 +88,7 @@ extern pgprot_t pgprot_s2_device; #define PAGE_HYP _MOD_PROT(pgprot_kernel, L_PTE_HYP) #define PAGE_HYP_DEVICE _MOD_PROT(pgprot_hyp_device, L_PTE_HYP) #define PAGE_S2 _MOD_PROT(pgprot_s2, L_PTE_S2_RDONLY) -#define PAGE_S2_DEVICE _MOD_PROT(pgprot_s2_device, L_PTE_USER | L_PTE_S2_RDONLY) +#define PAGE_S2_DEVICE _MOD_PROT(pgprot_s2_device, L_PTE_S2_RDONLY) #define __PAGE_NONE __pgprot(_L_PTE_DEFAULT | L_PTE_RDONLY | L_PTE_XN | L_PTE_NONE) #define __PAGE_SHARED __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_XN)
THe L_PTE_USER actually has nothing to do with stage 2 mappings and the L_PTE_S2_RDONLY value sets the readable bit, which was what L_PTE_USER was used for before proper handling of stage 2 memory defines. Signed-off-by: Christoffer Dall <cdall@cs.columbia.edu> --- arch/arm/include/asm/pgtable.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)