Ram Pai <linuxram@xxxxxxxxxx> writes:
> 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.
>
> x86 arch_show_smap() function is not needed anymore.
> Delete it.
>
> Signed-off-by: Ram Pai <linuxram@xxxxxxxxxx>
> ---
> arch/x86/kernel/setup.c | 8 --------
> fs/proc/task_mmu.c | 11 ++++++-----
> 2 files changed, 6 insertions(+), 13 deletions(-)
>
> 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..4b39a94 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 +848,13 @@ 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);
> +#ifdef CONFIG_ARCH_HAS_PKEYS
> + if (arch_pkeys_enabled())
> + seq_printf(m, "ProtectionKey: %8u\n", vma_pkey(vma));
> +#endif
Would it be worth it making vma_pkey a noop on architectures that don't
support protection keys so that we don't need the #ifdef here?
Eric
> show_smap_vma_flags(m, vma);
> }
> +
> m_cache_vma(m, vma);
> return ret;
> }
