linux-stable/mm
Rick Edgecombe 44bd7ace9f mm: take placement mappings gap into account
When memory is being placed, mmap() will take care to respect the guard
gaps of certain types of memory (VM_SHADOWSTACK, VM_GROWSUP and
VM_GROWSDOWN).  In order to ensure guard gaps between mappings, mmap()
needs to consider two things:

 1. That the new mapping isn't placed in an any existing mappings guard
    gaps.
 2. That the new mapping isn't placed such that any existing mappings
    are not in *its* guard gaps.

The longstanding behavior of mmap() is to ensure 1, but not take any care
around 2.  So for example, if there is a PAGE_SIZE free area, and a mmap()
with a PAGE_SIZE size, and a type that has a guard gap is being placed,
mmap() may place the shadow stack in the PAGE_SIZE free area.  Then the
mapping that is supposed to have a guard gap will not have a gap to the
adjacent VMA.

For MAP_GROWSDOWN/VM_GROWSDOWN and MAP_GROWSUP/VM_GROWSUP this has not
been a problem in practice because applications place these kinds of
mappings very early, when there is not many mappings to find a space
between.  But for shadow stacks, they may be placed throughout the
lifetime of the application.

Use the start_gap field to find a space that includes the guard gap for
the new mapping.  Take care to not interfere with the alignment.

Link: https://lkml.kernel.org/r/20240326021656.202649-12-rick.p.edgecombe@intel.com
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Aneesh Kumar K.V <aneesh.kumar@kernel.org>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Deepak Gupta <debug@rivosinc.com>
Cc: Guo Ren <guoren@kernel.org>
Cc: Helge Deller <deller@gmx.de>
Cc: H. Peter Anvin (Intel) <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Naveen N. Rao <naveen.n.rao@linux.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25 20:56:28 -07:00
..
damon mm: madvise: pageout: ignore references rather than clearing young 2024-03-04 17:01:18 -08:00
kasan fix missing vmalloc.h includes 2024-04-25 20:55:49 -07:00
kfence mm: introduce slabobj_ext to support slab object extensions 2024-04-25 20:55:51 -07:00
kmsan mm: kmsan: remove runtime checks from kmsan_unpoison_memory() 2024-02-22 10:24:41 -08:00
Kconfig mm/Kconfig: CONFIG_PGTABLE_HAS_HUGE_LEAVES 2024-04-25 20:56:20 -07:00
Kconfig.debug mm/slub: unify all sl[au]b parameters with "slab_$param" 2024-01-22 10:31:08 +01:00
Makefile mm/kmemleak: disable KASAN instrumentation in kmemleak 2024-04-25 20:56:05 -07:00
backing-dev.c mm: backing-dev: use group allocation/free of per-cpu counters API 2024-04-25 20:56:12 -07:00
balloon_compaction.c
bootmem_info.c bootmem: use kmemleak_free_part_phys in put_page_bootmem 2023-10-25 16:47:13 -07:00
cma.c mm/cma: add sysfs file 'release_pages_success' 2024-02-22 10:24:57 -08:00
cma.h mm/cma: add sysfs file 'release_pages_success' 2024-02-22 10:24:57 -08:00
cma_debug.c
cma_sysfs.c mm/cma: add sysfs file 'release_pages_success' 2024-02-22 10:24:57 -08:00
compaction.c mm: enable page allocation tagging 2024-04-25 20:55:54 -07:00
debug.c mm: switch mm->get_unmapped_area() to a flag 2024-04-25 20:56:25 -07:00
debug_page_alloc.c mm: page_alloc: consolidate free page accounting 2024-04-25 20:56:04 -07:00
debug_page_ref.c
debug_vm_pgtable.c fix missing vmalloc.h includes 2024-04-25 20:55:49 -07:00
dmapool.c mm/mempool/dmapool: remove CONFIG_DEBUG_SLAB ifdefs 2023-12-05 11:17:58 +01:00
dmapool_test.c
early_ioremap.c
fadvise.c
fail_page_alloc.c
failslab.c
filemap.c mm/filemap: optimize filemap folio adding 2024-04-25 20:56:09 -07:00
folio-compat.c mm: remove __set_page_dirty_nobuffers() 2024-04-25 20:56:25 -07:00
gup.c mm/gup: handle hugetlb in the generic follow_page_mask code 2024-04-25 20:56:23 -07:00
gup_test.c
gup_test.h
highmem.c x86/kexec: use pr_err() instead of kexec_dprintk() when an error occurs 2023-12-29 12:22:28 -08:00
hmm.c mm/treewide: replace pXd_huge() with pXd_leaf() 2024-04-25 20:55:46 -07:00
huge_memory.c thp: add thp_get_unmapped_area_vmflags() 2024-04-25 20:56:26 -07:00
hugetlb.c mm/gup: handle hugetlb in the generic follow_page_mask code 2024-04-25 20:56:23 -07:00
hugetlb_cgroup.c mm, hugetlb: remove HUGETLB_CGROUP_MIN_ORDER 2023-10-18 14:34:17 -07:00
hugetlb_vmemmap.c mm: hugetlb_vmemmap: move mmap lock to vmemmap_remap_range() 2023-12-12 10:57:08 -08:00
hugetlb_vmemmap.h mm: hugetlb_vmemmap: fix reference to nonexistent file 2023-10-25 16:47:14 -07:00
hwpoison-inject.c
init-mm.c mm: Deprecate pasid field 2023-12-12 10:11:32 +01:00
internal.h mm: allow anon exclusive check over hugetlb tail pages 2024-04-25 20:56:23 -07:00
interval_tree.c
io-mapping.c
ioremap.c mm: ioremap: remove unneeded ioremap_allowed and iounmap_allowed 2023-08-18 10:12:36 -07:00
khugepaged.c mm: convert free_swap_cache() to take a folio 2024-03-04 17:01:26 -08:00
kmemleak.c mm/kmemleak: compact kmemleak_object further 2024-04-25 20:56:05 -07:00
ksm.c mm: convert page_try_share_anon_rmap() to folio_try_share_anon_rmap_[pte|pmd]() 2023-12-29 11:58:56 -08:00
list_lru.c mm/zswap: stop lru list shrinking when encounter warm region 2024-02-22 10:24:54 -08:00
maccess.c
madvise.c mm: add pmd_folio() 2024-04-25 20:56:19 -07:00
mapping_dirty_helpers.c mm: fix clean_record_shared_mapping_range kernel-doc 2023-08-24 16:20:30 -07:00
memblock.c cxl fixes for 6.8-rc6 2024-02-24 15:53:40 -08:00
memcontrol.c mm, slab: move slab_memcg hooks to mm/memcontrol.c 2024-04-25 20:56:16 -07:00
memfd.c mm/memfd: refactor memfd_tag_pins() and memfd_wait_for_pins() 2024-03-04 17:01:21 -08:00
memory-failure.c mm: record the migration reason for struct migration_target_control 2024-04-25 20:56:06 -07:00
memory-tiers.c mm/demotion: print demotion targets 2024-02-22 10:24:55 -08:00
memory.c mm: introduce vma_pgtable_walk_{begin|end}() 2024-04-25 20:56:21 -07:00
memory_hotplug.c mm: record the migration reason for struct migration_target_control 2024-04-25 20:56:06 -07:00
mempolicy.c mm: add pmd_folio() 2024-04-25 20:56:19 -07:00
mempool.c mempool: hook up to memory allocation profiling 2024-04-25 20:55:56 -07:00
memremap.c mm: remove stale example from comment 2023-12-29 11:58:26 -08:00
memtest.c memtest: use {READ,WRITE}_ONCE in memory scanning 2024-03-13 12:12:21 -07:00
migrate.c remove references to page->flags in documentation 2024-04-25 20:56:15 -07:00
migrate_device.c mm: convert migrate_vma_collect_pmd to use a folio 2024-04-25 20:56:19 -07:00
mincore.c mm: enable page walking API to lock vmas during the walk 2023-08-21 13:07:20 -07:00
mlock.c mm: add pmd_folio() 2024-04-25 20:56:19 -07:00
mm_init.c mm/mm_init.c: remove the outdated code comment above deferred_grow_zone() 2024-04-25 20:56:17 -07:00
mm_slot.h
mmap.c mm: take placement mappings gap into account 2024-04-25 20:56:28 -07:00
mmap_lock.c
mmu_gather.c mm/mmu_gather: improve cond_resched() handling with large folios and expensive page freeing 2024-02-22 15:27:17 -08:00
mmu_notifier.c mmu_notifiers: rename invalidate_range notifier 2023-08-18 10:12:41 -07:00
mmzone.c zswap: shrink zswap pool based on memory pressure 2023-12-12 10:57:02 -08:00
mprotect.c mprotect: use pfn_swap_entry_folio 2024-02-21 16:00:03 -08:00
mremap.c mm: remove "prot" parameter from move_pte() 2024-04-25 20:56:24 -07:00
msync.c
nommu.c mm: remove follow_pfn 2024-04-25 20:56:12 -07:00
oom_kill.c mm: update mark_victim tracepoints fields 2024-03-04 17:01:16 -08:00
page-writeback.c writeback: remove a use of write_cache_pages() from do_writepages() 2024-02-23 17:48:38 -08:00
page_alloc.c mm/page_alloc.c: change the array-length to MIGRATE_PCPTYPES 2024-04-25 20:56:18 -07:00
page_counter.c
page_ext.c mm: make page_ext_get() take a const argument 2024-04-25 20:56:14 -07:00
page_idle.c
page_io.c arm64: mm: swap: support THP_SWAP on hardware with MTE 2024-04-25 20:56:07 -07:00
page_isolation.c mm: page_isolation: prepare for hygienic freelists 2024-04-25 20:56:04 -07:00
page_owner.c mm: introduce slabobj_ext to support slab object extensions 2024-04-25 20:55:51 -07:00
page_poison.c mm/page_poison: replace kmap_atomic() with kmap_local_page() 2023-12-10 16:51:50 -08:00
page_reporting.c mm, treewide: rename MAX_ORDER to MAX_PAGE_ORDER 2024-01-08 15:27:15 -08:00
page_reporting.h
page_table_check.c mm: convert page_table_check_pte_set() to page_table_check_ptes_set() 2023-08-24 16:20:18 -07:00
page_vma_mapped.c mm: thp: introduce multi-size THP sysfs interface 2023-12-20 14:48:12 -08:00
pagewalk.c mm: pagewalk: assert write mmap lock only for walking the user page tables 2023-12-10 16:51:53 -08:00
percpu-internal.h mm: percpu: add codetag reference into pcpuobj_ext 2024-04-25 20:55:56 -07:00
percpu-km.c
percpu-stats.c
percpu-vm.c percpu: clean up all mappings when pcpu_map_pages() fails 2024-04-25 20:55:49 -07:00
percpu.c mm: percpu: enable per-cpu allocation tagging 2024-04-25 20:55:56 -07:00
pgalloc-track.h
pgtable-generic.c mm/pgtable: notes on pte_offset_map[_lock]() 2023-08-18 10:12:25 -07:00
process_vm_access.c mm: fix process_vm_rw page counts 2023-12-10 16:51:39 -08:00
ptdump.c mm: ptdump: add check_wx_pages debugfs attribute 2024-02-22 10:24:47 -08:00
readahead.c mm/readahead: break read-ahead loop if filemap_add_folio return -ENOMEM 2024-04-25 20:56:07 -07:00
rmap.c remove references to page->flags in documentation 2024-04-25 20:56:15 -07:00
rodata_test.c
secretmem.c mm/secretmem: use a folio in secretmem_fault() 2023-08-21 13:38:02 -07:00
shmem.c mm: switch mm->get_unmapped_area() to a flag 2024-04-25 20:56:25 -07:00
shmem_quota.c tmpfs: fix race on handling dquot rbtree 2024-03-26 11:07:23 -07:00
show_mem.c lib: add memory allocations report in show_mem() 2024-04-25 20:55:57 -07:00
shrinker.c mm: shrinker: use kvzalloc_node() from expand_one_shrinker_info() 2024-01-05 09:58:32 -08:00
shrinker_debug.c mm: shrinker: convert shrinker_rwsem to mutex 2023-10-04 10:32:26 -07:00
shuffle.c
shuffle.h mm, treewide: rename MAX_ORDER to MAX_PAGE_ORDER 2024-01-08 15:27:15 -08:00
slab.h mm, slab: move slab_memcg hooks to mm/memcontrol.c 2024-04-25 20:56:16 -07:00
slab_common.c mm/slab: enable slab allocation tagging for kmalloc and friends 2024-04-25 20:55:55 -07:00
slub.c mm, slab: move slab_memcg hooks to mm/memcontrol.c 2024-04-25 20:56:16 -07:00
sparse-vmemmap.c mm/vmemmap: allow architectures to override how vmemmap optimization works 2023-08-18 10:12:53 -07:00
sparse.c mm: move array mem_section init code out of memory_present() 2024-04-25 20:56:16 -07:00
swap.c mm: add is_huge_zero_folio() 2024-04-25 20:56:18 -07:00
swap.h mm/swap: fix race when skipping swapcache 2024-02-20 14:20:48 -08:00
swap_cgroup.c
swap_slots.c arm64: mm: swap: support THP_SWAP on hardware with MTE 2024-04-25 20:56:07 -07:00
swap_state.c mm: add is_huge_zero_folio() 2024-04-25 20:56:18 -07:00
swapfile.c arm64: mm: swap: support THP_SWAP on hardware with MTE 2024-04-25 20:56:07 -07:00
truncate.c fs: convert error_remove_page to error_remove_folio 2023-12-10 16:51:42 -08:00
usercopy.c
userfaultfd.c mm: add pmd_folio() 2024-04-25 20:56:19 -07:00
util.c mm: switch mm->get_unmapped_area() to a flag 2024-04-25 20:56:25 -07:00
vmalloc.c mm/vmalloc.c: optimize to reduce arguments of alloc_vmap_area() 2024-04-25 20:56:08 -07:00
vmpressure.c eventfd: simplify eventfd_signal() 2023-11-28 14:08:38 +01:00
vmscan.c mm: hold PTL from the first PTE while reclaiming a large folio 2024-04-25 20:56:08 -07:00
vmstat.c mm, treewide: rename MAX_ORDER to MAX_PAGE_ORDER 2024-01-08 15:27:15 -08:00
workingset.c mm: move mapping_set_update out of <linux/swap.h> 2024-02-21 11:36:50 +05:30
z3fold.c mm: zpool: return pool size in pages 2024-04-25 20:55:48 -07:00
zbud.c mm: zpool: return pool size in pages 2024-04-25 20:55:48 -07:00
zpool.c mm: zpool: return pool size in pages 2024-04-25 20:55:48 -07:00
zsmalloc.c mm: zpool: return pool size in pages 2024-04-25 20:55:48 -07:00
zswap.c zswap: replace RB tree with xarray 2024-04-25 20:56:18 -07:00