linux.git/arch/um/include/asm, branch v6.6

Merge tag 'x86_shstk_for_6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2023-08-31T19:20:12+00:00

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
  ...

um: implement the new page table range API

2023-08-24T23:20:24+00:00

Add PFN_PTE_SHIFT and update_mmu_cache_range().

Link: https://lkml.kernel.org/r/20230802151406.3735276-28-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) 
Acked-by: Mike Rapoport (IBM) 
Cc: Richard Weinberger 
Cc: Anton Ivanov 
Cc: Johannes Berg 
Signed-off-by: Andrew Morton

um: convert {pmd, pte}_free_tlb() to use ptdescs

2023-08-21T20:37:58+00:00

Part of the conversions to replace pgtable constructor/destructors with
ptdesc equivalents.  Also cleans up some spacing issues.

Link: https://lkml.kernel.org/r/20230807230513.102486-31-vishal.moola@gmail.com
Signed-off-by: Vishal Moola (Oracle) 
Acked-by: Mike Rapoport (IBM) 
Cc: Arnd Bergmann 
Cc: Catalin Marinas 
Cc: Christophe Leroy 
Cc: Claudio Imbrenda 
Cc: Dave Hansen 
Cc: David Hildenbrand 
Cc: "David S. Miller" 
Cc: Dinh Nguyen 
Cc: Geert Uytterhoeven 
Cc: Geert Uytterhoeven 
Cc: Guo Ren 
Cc: Huacai Chen 
Cc: Hugh Dickins 
Cc: John Paul Adrian Glaubitz 
Cc: Jonas Bonn 
Cc: Matthew Wilcox 
Cc: Palmer Dabbelt 
Cc: Paul Walmsley 
Cc: Richard Weinberger 
Cc: Thomas Bogendoerfer 
Cc: Yoshinori Sato 
Signed-off-by: Andrew Morton

mm: Rename arch pte_mkwrite()'s to pte_mkwrite_novma()

2023-07-11T21:10:56+00:00

The x86 Shadow stack feature includes a new type of memory called shadow
stack. This shadow stack memory has some unusual properties, which requires
some core mm changes to function properly.

One of these unusual properties is that shadow stack memory is writable,
but only in limited ways. These limits are applied via a specific PTE
bit combination. Nevertheless, the memory is writable, and core mm code
will need to apply the writable permissions in the typical paths that
call pte_mkwrite(). The goal is to make pte_mkwrite() take a VMA, so
that the x86 implementation of it can know whether to create regular
writable or shadow stack mappings.

But there are a couple of challenges to this. Modifying the signatures of
each arch pte_mkwrite() implementation would be error prone because some
are generated with macros and would need to be re-implemented. Also, some
pte_mkwrite() callers operate on kernel memory without a VMA.

So this can be done in a three step process. First pte_mkwrite() can be
renamed to pte_mkwrite_novma() in each arch, with a generic pte_mkwrite()
added that just calls pte_mkwrite_novma(). Next callers without a VMA can
be moved to pte_mkwrite_novma(). And lastly, pte_mkwrite() and all callers
can be changed to take/pass a VMA.

Start the process by renaming pte_mkwrite() to pte_mkwrite_novma() and
adding the pte_mkwrite() wrapper in linux/pgtable.h. Apply the same
pattern for pmd_mkwrite(). Since not all archs have a pmd_mkwrite_novma(),
create a new arch config HAS_HUGE_PAGE that can be used to tell if
pmd_mkwrite() should be defined. Otherwise in the !HAS_HUGE_PAGE cases the
compiler would not be able to find pmd_mkwrite_novma().

No functional change.

Suggested-by: Linus Torvalds 
Signed-off-by: Rick Edgecombe 
Signed-off-by: Dave Hansen 
Reviewed-by: Mike Rapoport (IBM) 
Acked-by: Geert Uytterhoeven 
Acked-by: David Hildenbrand 
Link: https://lore.kernel.org/lkml/CAHk-=wiZjSu7c9sFYZb3q04108stgHff2wfbokGCCgW7riz+8Q@mail.gmail.com/
Link: https://lore.kernel.org/all/20230613001108.3040476-2-rick.p.edgecombe%40intel.com

um/cpu: Switch to arch_cpu_finalize_init()

2023-06-16T08:16:00+00:00

check_bugs() is about to be phased out. Switch over to the new
arch_cpu_finalize_init() implementation.

No functional change.

Signed-off-by: Thomas Gleixner 
Acked-by: Richard Weinberger 
Link: https://lore.kernel.org/r/20230613224545.493148694@linutronix.de

Merge tag 'uml-for-linus-6.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/uml/linux

2023-03-01T17:13:00+00:00

Pull UML updates from Richard Weinberger:

 - Add support for rust (yay!)

 - Add support for LTO

 - Add platform bus support to virtio-pci

 - Various virtio fixes

 - Coding style, spelling cleanups

* tag 'uml-for-linus-6.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/uml/linux: (27 commits)
  Documentation: rust: Fix arch support table
  uml: vector: Remove unused definitions VECTOR_{WRITE,HEADERS}
  um: virt-pci: properly remove PCI device from bus
  um: virtio_uml: move device breaking into workqueue
  um: virtio_uml: mark device as unregistered when breaking it
  um: virtio_uml: free command if adding to virtqueue failed
  UML: define RUNTIME_DISCARD_EXIT
  virt-pci: add platform bus support
  um-virt-pci: Make max delay configurable
  um: virt-pci: implement pcibios_get_phb_of_node()
  um: Support LTO
  um: put power options in a menu
  um: Use CFLAGS_vmlinux
  um: Prevent building modules incompatible with MODVERSIONS
  um: Avoid pcap multiple definition errors
  um: Make the definition of cpu_data more compatible
  x86: um: vdso: Add '%rcx' and '%r11' to the syscall clobber list
  rust: arch/um: Add support for CONFIG_RUST under x86_64 UML
  rust: arch/um: Disable FP/SIMD instruction to match x86
  rust: arch/um: Use 'pie' relocation mode under UML
  ...

um: Make the definition of cpu_data more compatible

2023-02-10T20:36:58+00:00

Match the x86 implementation to improve build errors.
Noticed when building allyesconfig.

e.g.
../arch/um/include/asm/processor-generic.h:94:19: error: called object is not a function or function pointer
   94 | #define cpu_data (&boot_cpu_data)
      |                  ~^~~~~~~~~~~~~~~
../drivers/gpu/drm/amd/amdgpu/../amdkfd/kfd_topology.c:2157:16: note: in expansion of macro ‘cpu_data’
 2157 |         return cpu_data(first_cpu_of_numa_node).apicid;

Signed-off-by: Peter Foley 
Signed-off-by: Richard Weinberger

mm, arch: add generic implementation of pfn_valid() for FLATMEM

2023-02-10T00:51:41+00:00

Every architecture that supports FLATMEM memory model defines its own
version of pfn_valid() that essentially compares a pfn to max_mapnr.

Use mips/powerpc version implemented as static inline as a generic
implementation of pfn_valid() and drop its per-architecture definitions.

[rppt@kernel.org: fix the generic pfn_valid()]
  Link: https://lkml.kernel.org/r/Y9lg7R1Yd931C+y5@kernel.org
Link: https://lkml.kernel.org/r/20230129124235.209895-5-rppt@kernel.org
Signed-off-by: Mike Rapoport (IBM) 
Acked-by: Arnd Bergmann 
Acked-by: Guo Ren 		[csky]
Acked-by: Huacai Chen 	[LoongArch]
Acked-by: Stafford Horne 	[OpenRISC]
Acked-by: Michael Ellerman 	[powerpc]
Reviewed-by: David Hildenbrand 
Tested-by: Conor Dooley 
Cc: Brian Cain 
Cc: "David S. Miller" 
Cc: Dinh Nguyen 
Cc: Geert Uytterhoeven 
Cc: Greg Ungerer 
Cc: Helge Deller 
Cc: Huacai Chen 
Cc: Matt Turner 
Cc: Max Filippov 
Cc: Michal Simek 
Cc: Palmer Dabbelt 
Cc: Richard Weinberger 
Cc: Rich Felker 
Cc: Russell King 
Cc: Thomas Bogendoerfer 
Cc: Vineet Gupta 
Cc: WANG Xuerui 
Cc: Yoshinori Sato 
Signed-off-by: Andrew Morton

mm: remove __HAVE_ARCH_PTE_SWP_EXCLUSIVE

2023-02-03T06:33:11+00:00

__HAVE_ARCH_PTE_SWP_EXCLUSIVE is now supported by all architectures that
support swp PTEs, so let's drop it.

Link: https://lkml.kernel.org/r/20230113171026.582290-27-david@redhat.com
Signed-off-by: David Hildenbrand 
Signed-off-by: Andrew Morton

um/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE

2023-02-03T06:33:10+00:00

Let's support __HAVE_ARCH_PTE_SWP_EXCLUSIVE by using bit 10, which is yet
unused for swap PTEs.

The pte_mkuptodate() is a bit weird in __pte_to_swp_entry() for a swap PTE
...  but it only messes with bit 1 and 2 and there is a comment in
set_pte(), so leave these bits alone.

While at it, mask the type in __swp_entry().

Link: https://lkml.kernel.org/r/20230113171026.582290-24-david@redhat.com
Signed-off-by: David Hildenbrand 
Cc: Richard Weinberger 
Cc: Anton Ivanov 
Cc: Johannes Berg 
Signed-off-by: Andrew Morton