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authorLinus Torvalds <torvalds@linux-foundation.org>2023-08-31 12:20:12 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2023-08-31 12:20:12 -0700
commitdf57721f9a63e8a1fb9b9b2e70de4aa4c7e0cd2e (patch)
treeb77ba91405ebc69c36ccbb55476ed0d018d7fba4 /mm/gup.c
parentb97d64c722598ffed42ece814a2cb791336c6679 (diff)
parent1fe428d3692fb10a0e8d85fafe719b154e43ad4e (diff)
Merge tag 'x86_shstk_for_6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 shadow stack support from Dave Hansen: "This is the long awaited x86 shadow stack support, part of Intel's Control-flow Enforcement Technology (CET). CET consists of two related security features: shadow stacks and indirect branch tracking. This series implements just the shadow stack part of this feature, and just for userspace. The main use case for shadow stack is providing protection against return oriented programming attacks. It works by maintaining a secondary (shadow) stack using a special memory type that has protections against modification. When executing a CALL instruction, the processor pushes the return address to both the normal stack and to the special permission shadow stack. Upon RET, the processor pops the shadow stack copy and compares it to the normal stack copy. For more information, refer to the links below for the earlier versions of this patch set" Link: https://lore.kernel.org/lkml/20220130211838.8382-1-rick.p.edgecombe@intel.com/ Link: https://lore.kernel.org/lkml/20230613001108.3040476-1-rick.p.edgecombe@intel.com/ * tag 'x86_shstk_for_6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (47 commits) x86/shstk: Change order of __user in type x86/ibt: Convert IBT selftest to asm x86/shstk: Don't retry vm_munmap() on -EINTR x86/kbuild: Fix Documentation/ reference x86/shstk: Move arch detail comment out of core mm x86/shstk: Add ARCH_SHSTK_STATUS x86/shstk: Add ARCH_SHSTK_UNLOCK x86: Add PTRACE interface for shadow stack selftests/x86: Add shadow stack test x86/cpufeatures: Enable CET CR4 bit for shadow stack x86/shstk: Wire in shadow stack interface x86: Expose thread features in /proc/$PID/status x86/shstk: Support WRSS for userspace x86/shstk: Introduce map_shadow_stack syscall x86/shstk: Check that signal frame is shadow stack mem x86/shstk: Check that SSP is aligned on sigreturn x86/shstk: Handle signals for shadow stack x86/shstk: Introduce routines modifying shstk x86/shstk: Handle thread shadow stack x86/shstk: Add user-mode shadow stack support ...
Diffstat (limited to 'mm/gup.c')
-rw-r--r--mm/gup.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/gup.c b/mm/gup.c
index 948f3b454b00..2f8a2d89fde1 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -1051,7 +1051,7 @@ static int check_vma_flags(struct vm_area_struct *vma, unsigned long gup_flags)
!writable_file_mapping_allowed(vma, gup_flags))
return -EFAULT;
- if (!(vm_flags & VM_WRITE)) {
+ if (!(vm_flags & VM_WRITE) || (vm_flags & VM_SHADOW_STACK)) {
if (!(gup_flags & FOLL_FORCE))
return -EFAULT;
/* hugetlb does not support FOLL_FORCE|FOLL_WRITE. */