From 2c2d57b5e769956fb36581e0d3cccdb5ea68038f Mon Sep 17 00:00:00 2001 From: Khalid Aziz <khalid.aziz@oracle.com> Date: Wed, 21 Feb 2018 10:15:50 -0700 Subject: [PATCH] mm: Clear arch specific VM flags on protection change When protection bits are changed on a VMA, some of the architecture specific flags should be cleared as well. An examples of this are the PKEY flags on x86. This patch expands the current code that clears PKEY flags for x86, to support similar functionality for other architectures as well. Signed-off-by: Khalid Aziz <khalid.aziz@oracle.com> Cc: Khalid Aziz <khalid@gonehiking.org> Reviewed-by: Anthony Yznaga <anthony.yznaga@oracle.com> Acked-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: David S. Miller <davem@davemloft.net> --- include/linux/mm.h | 6 ++++++ mm/mprotect.c | 2 +- 2 files changed, 7 insertions(+), 1 deletion(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index ad06d42adb1a2..ae806dbc63eef 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -287,6 +287,12 @@ extern unsigned int kobjsize(const void *objp); /* This mask is used to clear all the VMA flags used by mlock */ #define VM_LOCKED_CLEAR_MASK (~(VM_LOCKED | VM_LOCKONFAULT)) +/* Arch-specific flags to clear when updating VM flags on protection change */ +#ifndef VM_ARCH_CLEAR +# define VM_ARCH_CLEAR VM_NONE +#endif +#define VM_FLAGS_CLEAR (ARCH_VM_PKEY_FLAGS | VM_ARCH_CLEAR) + /* * mapping from the currently active vm_flags protection bits (the * low four bits) to a page protection mask.. diff --git a/mm/mprotect.c b/mm/mprotect.c index 088ea9c086786..c1d6af7455da5 100644 --- a/mm/mprotect.c +++ b/mm/mprotect.c @@ -475,7 +475,7 @@ static int do_mprotect_pkey(unsigned long start, size_t len, * cleared from the VMA. */ mask_off_old_flags = VM_READ | VM_WRITE | VM_EXEC | - ARCH_VM_PKEY_FLAGS; + VM_FLAGS_CLEAR; new_vma_pkey = arch_override_mprotect_pkey(vma, prot, pkey); newflags = calc_vm_prot_bits(prot, new_vma_pkey); -- GitLab