On Tue 30-01-18 11:44:12, Ram Pai wrote:
> Currently the architecture specific code is expected to
> display the protection keys in smap for a given vma.
> This can lead to redundant code and possibly to divergent
> formats in which the key gets displayed.
>
> This patch changes the implementation. It displays the
> pkey only if the architecture support pkeys, i.e
> arch_pkeys_enabled() returns true. This patch
> provides x86 implementation for arch_pkeys_enabled().
>
> x86 arch_show_smap() function is not needed anymore.
> Deleting it.
Thanks for reworking this patch. Looks good to me.
> Signed-off-by: Ram Pai <linuxram@xxxxxxxxxx>
Acked-by: Michal Hocko <mhocko@xxxxxxxx>
> ---
> arch/x86/include/asm/pkeys.h | 1 +
> arch/x86/kernel/fpu/xstate.c | 5 +++++
> arch/x86/kernel/setup.c | 8 --------
> fs/proc/task_mmu.c | 9 ++++-----
> include/linux/pkeys.h | 6 ++++++
> 5 files changed, 16 insertions(+), 13 deletions(-)
>
> diff --git a/arch/x86/include/asm/pkeys.h b/arch/x86/include/asm/pkeys.h
> index a0ba1ff..f6c287b 100644
> --- a/arch/x86/include/asm/pkeys.h
> +++ b/arch/x86/include/asm/pkeys.h
> @@ -6,6 +6,7 @@
>
> extern int arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
> unsigned long init_val);
> +extern bool arch_pkeys_enabled(void);
>
> /*
> * Try to dedicate one of the protection keys to be used as an
> diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
> index 87a57b7..4f566e9 100644
> --- a/arch/x86/kernel/fpu/xstate.c
> +++ b/arch/x86/kernel/fpu/xstate.c
> @@ -945,6 +945,11 @@ int arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
>
> return 0;
> }
> +
> +bool arch_pkeys_enabled(void)
> +{
> + return boot_cpu_has(X86_FEATURE_OSPKE);
> +}
> #endif /* ! CONFIG_ARCH_HAS_PKEYS */
>
> /*
> diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
> index 8af2e8d..ddf945a 100644
> --- a/arch/x86/kernel/setup.c
> +++ b/arch/x86/kernel/setup.c
> @@ -1326,11 +1326,3 @@ static int __init register_kernel_offset_dumper(void)
> return 0;
> }
> __initcall(register_kernel_offset_dumper);
> -
> -void arch_show_smap(struct seq_file *m, struct vm_area_struct *vma)
> -{
> - if (!boot_cpu_has(X86_FEATURE_OSPKE))
> - return;
> -
> - seq_printf(m, "ProtectionKey: %8u\n", vma_pkey(vma));
> -}
> diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
> index 0edd4da..6f9fbde 100644
> --- a/fs/proc/task_mmu.c
> +++ b/fs/proc/task_mmu.c
> @@ -18,6 +18,7 @@
> #include <linux/page_idle.h>
> #include <linux/shmem_fs.h>
> #include <linux/uaccess.h>
> +#include <linux/pkeys.h>
>
> #include <asm/elf.h>
> #include <asm/tlb.h>
> @@ -728,10 +729,6 @@ static int smaps_hugetlb_range(pte_t *pte, unsigned long hmask,
> }
> #endif /* HUGETLB_PAGE */
>
> -void __weak arch_show_smap(struct seq_file *m, struct vm_area_struct *vma)
> -{
> -}
> -
> static int show_smap(struct seq_file *m, void *v, int is_pid)
> {
> struct proc_maps_private *priv = m->private;
> @@ -851,9 +848,11 @@ static int show_smap(struct seq_file *m, void *v, int is_pid)
> (unsigned long)(mss->pss >> (10 + PSS_SHIFT)));
>
> if (!rollup_mode) {
> - arch_show_smap(m, vma);
> + if (arch_pkeys_enabled())
> + seq_printf(m, "ProtectionKey: %8u\n", vma_pkey(vma));
> show_smap_vma_flags(m, vma);
> }
> +
> m_cache_vma(m, vma);
> return ret;
> }
> diff --git a/include/linux/pkeys.h b/include/linux/pkeys.h
> index 0794ca7..dfdc609 100644
> --- a/include/linux/pkeys.h
> +++ b/include/linux/pkeys.h
> @@ -13,6 +13,7 @@
> #define arch_override_mprotect_pkey(vma, prot, pkey) (0)
> #define PKEY_DEDICATED_EXECUTE_ONLY 0
> #define ARCH_VM_PKEY_FLAGS 0
> +#define vma_pkey(vma) 0
>
> static inline bool mm_pkey_is_allocated(struct mm_struct *mm, int pkey)
> {
> @@ -35,6 +36,11 @@ static inline int arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
> return 0;
> }
>
> +static inline bool arch_pkeys_enabled(void)
> +{
> + return false;
> +}
> +
> static inline void copy_init_pkru_to_fpregs(void)
> {
> }
> --
> 1.7.1
--
Michal Hocko
SUSE Labs
