Re: [RFC v4 01/17] mm: introduce an additional vma bit for powerpc pkey
From: Balbir Singh <bsingharora@gmail.com>
Date: 2017-06-27 10:55:10
Also in:
linux-arch, linux-mm, lkml
On Tue, 2017-06-27 at 03:11 -0700, Ram Pai wrote:
quoted hunk ↗ jump to hunk
Currently there are only 4bits in the vma flags to support 16 keys on x86. powerpc supports 32 keys, which needs 5bits. This patch introduces an addition bit in the vma flags. Signed-off-by: Ram Pai <redacted> --- fs/proc/task_mmu.c | 6 +++++- include/linux/mm.h | 18 +++++++++++++----- 2 files changed, 18 insertions(+), 6 deletions(-)diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index f0c8b33..2ddc298 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c@@ -666,12 +666,16 @@ static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma) [ilog2(VM_MERGEABLE)] = "mg", [ilog2(VM_UFFD_MISSING)]= "um", [ilog2(VM_UFFD_WP)] = "uw", -#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS +#ifdef CONFIG_ARCH_HAS_PKEYS /* These come out via ProtectionKey: */ [ilog2(VM_PKEY_BIT0)] = "", [ilog2(VM_PKEY_BIT1)] = "", [ilog2(VM_PKEY_BIT2)] = "", [ilog2(VM_PKEY_BIT3)] = "", +#endif /* CONFIG_ARCH_HAS_PKEYS */ +#ifdef CONFIG_PPC64_MEMORY_PROTECTION_KEYS + /* Additional bit in ProtectionKey: */ + [ilog2(VM_PKEY_BIT4)] = "", #endif
Not sure why these are linked with smap bits, but I guess the keys live in the Supervisor Mode Access Prevention area? Balbir Singh.