Commit 8c7c1b55 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'mm-stable-2025-04-02-22-07' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm 

Pull more MM updates from Andrew Morton:

 - The series "mm: fixes for fallouts from mem_init() cleanup" from Mike
   Rapoport fixes a couple of issues with the just-merged "arch, mm:
   reduce code duplication in mem_init()" series

 - The series "MAINTAINERS: add my isub-entries to MM part." from Mike
   Rapoport does some maintenance on MAINTAINERS

 - The series "remove tlb_remove_page_ptdesc()" from Qi Zheng does some
   cleanup work to the page mapping code

 - The series "mseal system mappings" from Jeff Xu permits sealing of
   "system mappings", such as vdso, vvar, vvar_vclock, vectors (arm
   compat-mode), sigpage (arm compat-mode)

 - Plus the usual shower of singleton patches

* tag 'mm-stable-2025-04-02-22-07' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (31 commits)
  mseal sysmap: add arch-support txt
  mseal sysmap: enable s390
  selftest: test system mappings are sealed
  mseal sysmap: update mseal.rst
  mseal sysmap: uprobe mapping
  mseal sysmap: enable arm64
  mseal sysmap: enable x86-64
  mseal sysmap: generic vdso vvar mapping
  selftests: x86: test_mremap_vdso: skip if vdso is msealed
  mseal sysmap: kernel config and header change
  mm: pgtable: remove tlb_remove_page_ptdesc()
  x86: pgtable: convert to use tlb_remove_ptdesc()
  riscv: pgtable: unconditionally use tlb_remove_ptdesc()
  mm: pgtable: convert some architectures to use tlb_remove_ptdesc()
  mm: pgtable: change pt parameter of tlb_remove_ptdesc() to struct ptdesc*
  mm: pgtable: make generic tlb_remove_table() use struct ptdesc
  microblaze/mm: put mm_cmdline_setup() in .init.text section
  mm/memory_hotplug: fix call folio_test_large with tail page in do_migrate_range
  MAINTAINERS: mm: add entry for secretmem
  MAINTAINERS: mm: add entry for numa memblocks and numa emulation
  ...
parents 204e9a18 e20706d5

Documentation/features/core/mseal_sys_mappings/arch-support.txt

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#

# Feature name:          mseal-system-mappings

#         Kconfig:       ARCH_SUPPORTS_MSEAL_SYSTEM_MAPPINGS

#         description:   arch supports mseal system mappings

#

    -----------------------

    |         arch |status|

    -----------------------

    |       alpha: | TODO |

    |         arc: |  N/A |

    |         arm: |  N/A |

    |       arm64: |  ok  |

    |        csky: |  N/A |

    |     hexagon: |  N/A |

    |   loongarch: | TODO |

    |        m68k: |  N/A |

    |  microblaze: |  N/A |

    |        mips: | TODO |

    |       nios2: |  N/A |

    |    openrisc: |  N/A |

    |      parisc: | TODO |

    |     powerpc: | TODO |

    |       riscv: | TODO |

    |        s390: |  ok  |

    |          sh: |  N/A |

    |       sparc: | TODO |

    |          um: | TODO |

    |         x86: |  ok  |

    |      xtensa: |  N/A |

    -----------------------

Documentation/userspace-api/mseal.rst

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@@ -130,6 +130,27 @@ Use cases 


- Chrome browser: protect some security sensitive data structures.



- System mappings:

  The system mappings are created by the kernel and includes vdso, vvar,

  vvar_vclock, vectors (arm compat-mode), sigpage (arm compat-mode), uprobes.



  Those system mappings are readonly only or execute only, memory sealing can

  protect them from ever changing to writable or unmmap/remapped as different

  attributes. This is useful to mitigate memory corruption issues where a

  corrupted pointer is passed to a memory management system.



  If supported by an architecture (CONFIG_ARCH_SUPPORTS_MSEAL_SYSTEM_MAPPINGS),

  the CONFIG_MSEAL_SYSTEM_MAPPINGS seals all system mappings of this

  architecture.



  The following architectures currently support this feature: x86-64, arm64,

  and s390.



  WARNING: This feature breaks programs which rely on relocating

  or unmapping system mappings. Known broken software at the time

  of writing includes CHECKPOINT_RESTORE, UML, gVisor, rr. Therefore

  this config can't be enabled universally.



When not to use mseal

=====================

Applications can apply sealing to any virtual memory region from userspace,

MAINTAINERS

+39 −0
Original line number Diff line number Diff line
@@ -15487,6 +15487,45 @@ F: tools/mm/ 
F:	tools/testing/selftests/mm/

N:	include/linux/page[-_]*









MEMORY MANAGEMENT - EXECMEM









M:	Andrew Morton <akpm@linux-foundation.org>









M:	Mike Rapoport <rppt@kernel.org>









L:	linux-mm@kvack.org









S:	Maintained









F:	include/linux/execmem.h









F:	mm/execmem.c

















MEMORY MANAGEMENT - NUMA MEMBLOCKS AND NUMA EMULATION









M:	Andrew Morton <akpm@linux-foundation.org>









M:	Mike Rapoport <rppt@kernel.org>









L:	linux-mm@kvack.org









S:	Maintained









F:	include/linux/numa_memblks.h









F:	mm/numa.c









F:	mm/numa_emulation.c









F:	mm/numa_memblks.c

















MEMORY MANAGEMENT - SECRETMEM









M:	Andrew Morton <akpm@linux-foundation.org>









M:	Mike Rapoport <rppt@kernel.org>









L:	linux-mm@kvack.org









S:	Maintained









F:	include/linux/secretmem.h









F:	mm/secretmem.c

















MEMORY MANAGEMENT - USERFAULTFD









M:	Andrew Morton <akpm@linux-foundation.org>









R:	Peter Xu <peterx@redhat.com>









L:	linux-mm@kvack.org









S:	Maintained









F:	Documentation/admin-guide/mm/userfaultfd.rst









F:	fs/userfaultfd.c









F:	include/asm-generic/pgtable_uffd.h









F:	include/linux/userfaultfd_k.h









F:	include/uapi/linux/userfaultfd.h









F:	mm/userfaultfd.c









F:	tools/testing/selftests/mm/uffd-*.[ch]

















MEMORY MAPPING









M:	Andrew Morton <akpm@linux-foundation.org>









M:	Liam R. Howlett <Liam.Howlett@oracle.com>
































arch/arm64/Kconfig



+1
−0






























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@@ -38,6 +38,7 @@ config ARM64







	select ARCH_HAS_KEEPINITRD









	select ARCH_HAS_MEMBARRIER_SYNC_CORE









	select ARCH_HAS_MEM_ENCRYPT









	select ARCH_SUPPORTS_MSEAL_SYSTEM_MAPPINGS









	select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS









	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE









	select ARCH_HAS_NONLEAF_PMD_YOUNG if ARM64_HAFT
































arch/arm64/kernel/vdso.c



+6
−3






























Original line number
Diff line number
Diff line







@@ -130,7 +130,8 @@ static int __setup_additional_pages(enum vdso_abi abi,







	mm->context.vdso = (void *)vdso_base;









	ret = _install_special_mapping(mm, vdso_base, vdso_text_len,









				       VM_READ|VM_EXEC|gp_flags|









				       VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,









				       VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC|









				       VM_SEALED_SYSMAP,









				       vdso_info[abi].cm);









	if (IS_ERR(ret))









		goto up_fail;








@@ -256,7 +257,8 @@ static int aarch32_kuser_helpers_setup(struct mm_struct *mm)







	 */









	ret = _install_special_mapping(mm, AARCH32_VECTORS_BASE, PAGE_SIZE,









				       VM_READ | VM_EXEC |









				       VM_MAYREAD | VM_MAYEXEC,









				       VM_MAYREAD | VM_MAYEXEC |









				       VM_SEALED_SYSMAP,









				       &aarch32_vdso_maps[AA32_MAP_VECTORS]);



















	return PTR_ERR_OR_ZERO(ret);








@@ -279,7 +281,8 @@ static int aarch32_sigreturn_setup(struct mm_struct *mm)







	 */









	ret = _install_special_mapping(mm, addr, PAGE_SIZE,









				       VM_READ | VM_EXEC | VM_MAYREAD |









				       VM_MAYWRITE | VM_MAYEXEC,









				       VM_MAYWRITE | VM_MAYEXEC |









				       VM_SEALED_SYSMAP,









				       &aarch32_vdso_maps[AA32_MAP_SIGPAGE]);









	if (IS_ERR(ret))









		goto out;