kernel/linux.git/mm/memblock.c, branch v5.15.208

memblock: allow to specify flags with memblock_add_node()

2023-12-20T14:17:33+00:00

[ Upstream commit 952eea9b01e4bbb7011329f1b7240844e61e5128 ] We want to specify flags when hotplugging memory. Let's prepare to pass flags to memblock_add_node() by adjusting all existing users. Note that when hotplugging memory the system is already up and running and we might have concurrent memblock users: for example, while we're hotplugging memory, kexec_file code might search for suitable memory regions to place kexec images. It's important to add the memory directly to memblock via a single call with the right flags, instead of adding the memory first and apply flags later: otherwise, concurrent memblock users might temporarily stumble over memblocks with wrong flags, which will be important in a follow-up patch that introduces a new flag to properly handle add_memory_driver_managed(). Link: https://lkml.kernel.org/r/20211004093605.5830-4-david@redhat.com Acked-by: Geert Uytterhoeven Acked-by: Heiko Carstens Signed-off-by: David Hildenbrand Acked-by: Shahab Vahedi [arch/arc] Reviewed-by: Mike Rapoport Cc: "Aneesh Kumar K . V" Cc: Arnd Bergmann Cc: Christian Borntraeger Cc: Eric Biederman Cc: Huacai Chen Cc: Jianyong Wu Cc: Jiaxun Yang Cc: Michal Hocko Cc: Oscar Salvador Cc: Thomas Bogendoerfer Cc: Vasily Gorbik Cc: Vineet Gupta Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Stable-dep-of: c7206e7bd214 ("MIPS: Loongson64: Handle more memory types passed from firmware") Signed-off-by: Sasha Levin

Revert "mm: Always release pages to the buddy allocator in memblock_free_late()."

2023-02-22T11:57:07+00:00

commit 647037adcad00f2bab8828d3d41cd0553d41f3bd upstream. This reverts commit 115d9d77bb0f9152c60b6e8646369fa7f6167593. The pages being freed by memblock_free_late() have already been initialized, but if they are in the deferred init range, __free_one_page() might access nearby uninitialized pages when trying to coalesce buddies. This can, for example, trigger this BUG: BUG: unable to handle page fault for address: ffffe964c02580c8 RIP: 0010:__list_del_entry_valid+0x3f/0x70 __free_one_page+0x139/0x410 __free_pages_ok+0x21d/0x450 memblock_free_late+0x8c/0xb9 efi_free_boot_services+0x16b/0x25c efi_enter_virtual_mode+0x403/0x446 start_kernel+0x678/0x714 secondary_startup_64_no_verify+0xd2/0xdb A proper fix will be more involved so revert this change for the time being. Fixes: 115d9d77bb0f ("mm: Always release pages to the buddy allocator in memblock_free_late().") Signed-off-by: Aaron Thompson Link: https://lore.kernel.org/r/20230207082151.1303-1-dev@aaront.org Signed-off-by: Mike Rapoport (IBM) Signed-off-by: Greg Kroah-Hartman

mm: Always release pages to the buddy allocator in memblock_free_late().

2023-01-18T10:48:57+00:00

[ Upstream commit 115d9d77bb0f9152c60b6e8646369fa7f6167593 ] If CONFIG_DEFERRED_STRUCT_PAGE_INIT is enabled, memblock_free_pages() only releases pages to the buddy allocator if they are not in the deferred range. This is correct for free pages (as defined by for_each_free_mem_pfn_range_in_zone()) because free pages in the deferred range will be initialized and released as part of the deferred init process. memblock_free_pages() is called by memblock_free_late(), which is used to free reserved ranges after memblock_free_all() has run. All pages in reserved ranges have been initialized at that point, and accordingly, those pages are not touched by the deferred init process. This means that currently, if the pages that memblock_free_late() intends to release are in the deferred range, they will never be released to the buddy allocator. They will forever be reserved. In addition, memblock_free_pages() calls kmsan_memblock_free_pages(), which is also correct for free pages but is not correct for reserved pages. KMSAN metadata for reserved pages is initialized by kmsan_init_shadow(), which runs shortly before memblock_free_all(). For both of these reasons, memblock_free_pages() should only be called for free pages, and memblock_free_late() should call __free_pages_core() directly instead. One case where this issue can occur in the wild is EFI boot on x86_64. The x86 EFI code reserves all EFI boot services memory ranges via memblock_reserve() and frees them later via memblock_free_late() (efi_reserve_boot_services() and efi_free_boot_services(), respectively). If any of those ranges happens to fall within the deferred init range, the pages will not be released and that memory will be unavailable. For example, on an Amazon EC2 t3.micro VM (1 GB) booting via EFI: v6.2-rc2: # grep -E 'Node|spanned|present|managed' /proc/zoneinfo Node 0, zone DMA spanned 4095 present 3999 managed 3840 Node 0, zone DMA32 spanned 246652 present 245868 managed 178867 v6.2-rc2 + patch: # grep -E 'Node|spanned|present|managed' /proc/zoneinfo Node 0, zone DMA spanned 4095 present 3999 managed 3840 Node 0, zone DMA32 spanned 246652 present 245868 managed 222816 # +43,949 pages Fixes: 3a80a7fa7989 ("mm: meminit: initialise a subset of struct pages if CONFIG_DEFERRED_STRUCT_PAGE_INIT is set") Signed-off-by: Aaron Thompson Link: https://lore.kernel.org/r/01010185892de53e-e379acfb-7044-4b24-b30a-e2657c1ba989-000000@us-west-2.amazonses.com Signed-off-by: Mike Rapoport (IBM) Signed-off-by: Sasha Levin

memblock: use kfree() to release kmalloced memblock regions

2022-03-02T10:48:10+00:00

commit c94afc46cae7ad41b2ad6a99368147879f4b0e56 upstream. memblock.{reserved,memory}.regions may be allocated using kmalloc() in memblock_double_array(). Use kfree() to release these kmalloced regions indicated by memblock_{reserved,memory}_in_slab. Signed-off-by: Miaohe Lin Fixes: 3010f876500f ("mm: discard memblock data later") Signed-off-by: Mike Rapoport Signed-off-by: Greg Kroah-Hartman

memblock: exclude MEMBLOCK_NOMAP regions from kmemleak

2021-10-22T04:30:49+00:00

Vladimir Zapolskiy reports: Commit a7259df76702 ("memblock: make memblock_find_in_range method private") invokes a kernel panic while running kmemleak on OF platforms with nomaped regions: Unable to handle kernel paging request at virtual address fff000021e00000 [...] scan_block+0x64/0x170 scan_gray_list+0xe8/0x17c kmemleak_scan+0x270/0x514 kmemleak_write+0x34c/0x4ac The memory allocated from memblock is registered with kmemleak, but if it is marked MEMBLOCK_NOMAP it won't have linear map entries so an attempt to scan such areas will fault. Ideally, memblock_mark_nomap() would inform kmemleak to ignore MEMBLOCK_NOMAP memory, but it can be called before kmemleak interfaces operating on physical addresses can use __va() conversion. Make sure that functions that mark allocated memory as MEMBLOCK_NOMAP take care of informing kmemleak to ignore such memory. Link: https://lore.kernel.org/all/8ade5174-b143-d621-8c8e-dc6a1898c6fb@linaro.org Link: https://lore.kernel.org/all/c30ff0a2-d196-c50d-22f0-bd50696b1205@quicinc.com Fixes: a7259df76702 ("memblock: make memblock_find_in_range method private") Reported-by: Vladimir Zapolskiy Signed-off-by: Mike Rapoport Reviewed-by: Catalin Marinas Tested-by: Vladimir Zapolskiy Tested-by: Qian Cai Signed-off-by: Linus Torvalds

Revert "memblock: exclude NOMAP regions from kmemleak"

2021-10-22T04:30:49+00:00

Commit 6e44bd6d34d6 ("memblock: exclude NOMAP regions from kmemleak") breaks boot on EFI systems with kmemleak and VM_DEBUG enabled: efi: Processing EFI memory map: efi: 0x000090000000-0x000091ffffff [Conventional| | | | | | | | | | |WB|WT|WC|UC] efi: 0x000092000000-0x0000928fffff [Runtime Data|RUN| | | | | | | | | |WB|WT|WC|UC] ------------[ cut here ]------------ kernel BUG at mm/kmemleak.c:1140! Internal error: Oops - BUG: 0 [#1] SMP Modules linked in: CPU: 0 PID: 0 Comm: swapper Not tainted 5.15.0-rc6-next-20211019+ #104 pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : kmemleak_free_part_phys+0x64/0x8c lr : kmemleak_free_part_phys+0x38/0x8c sp : ffff800011eafbc0 x29: ffff800011eafbc0 x28: 1fffff7fffb41c0d x27: fffffbfffda0e068 x26: 0000000092000000 x25: 1ffff000023d5f94 x24: ffff800011ed84d0 x23: ffff800011ed84c0 x22: ffff800011ed83d8 x21: 0000000000900000 x20: ffff800011782000 x19: 0000000092000000 x18: ffff800011ee0730 x17: 0000000000000000 x16: 0000000000000000 x15: 1ffff0000233252c x14: ffff800019a905a0 x13: 0000000000000001 x12: ffff7000023d5ed7 x11: 1ffff000023d5ed6 x10: ffff7000023d5ed6 x9 : dfff800000000000 x8 : ffff800011eaf6b7 x7 : 0000000000000001 x6 : ffff800011eaf6b0 x5 : 00008ffffdc2a12a x4 : ffff7000023d5ed7 x3 : 1ffff000023dbf99 x2 : 1ffff000022f0463 x1 : 0000000000000000 x0 : ffffffffffffffff Call trace: kmemleak_free_part_phys+0x64/0x8c memblock_mark_nomap+0x5c/0x78 reserve_regions+0x294/0x33c efi_init+0x2d0/0x490 setup_arch+0x80/0x138 start_kernel+0xa0/0x3ec __primary_switched+0xc0/0xc8 Code: 34000041 97d526e7 f9418e80 36000040 (d4210000) random: get_random_bytes called from print_oops_end_marker+0x34/0x80 with crng_init=0 ---[ end trace 0000000000000000 ]--- The crash happens because kmemleak_free_part_phys() tries to use __va() before memstart_addr is initialized and this triggers a VM_BUG_ON() in arch/arm64/include/asm/memory.h: Revert 6e44bd6d34d6 ("memblock: exclude NOMAP regions from kmemleak"), the issue it is fixing will be fixed differently. Reported-by: Qian Cai Signed-off-by: Mike Rapoport Acked-by: Catalin Marinas Signed-off-by: Linus Torvalds

memblock: check memory total_size

2021-10-19T06:22:03+00:00

mem=[X][G|M] is broken on ARM64 platform, there are cases that even type.cnt is 1, but total_size is not 0 because regions are merged into 1. So only check 'cnt' is not enough, total_size should be used, othersize bootargs 'mem=[X][G|B]' not work anymore. Link: https://lkml.kernel.org/r/20210930024437.32598-1-peng.fan@oss.nxp.com Fixes: e888fa7bb882 ("memblock: Check memory add/cap ordering") Signed-off-by: Peng Fan Reviewed-by: Mike Rapoport Cc: Geert Uytterhoeven Cc: David Hildenbrand Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

memblock: exclude NOMAP regions from kmemleak

2021-10-13T05:36:59+00:00

Vladimir Zapolskiy reports: commit a7259df76702 ("memblock: make memblock_find_in_range method private") invokes a kernel panic while running kmemleak on OF platforms with nomaped regions: Unable to handle kernel paging request at virtual address fff000021e00000 [...] scan_block+0x64/0x170 scan_gray_list+0xe8/0x17c kmemleak_scan+0x270/0x514 kmemleak_write+0x34c/0x4ac Indeed, NOMAP regions don't have linear map entries so an attempt to scan these areas would fault. Prevent such faults by excluding NOMAP regions from kmemleak. Link: https://lore.kernel.org/all/8ade5174-b143-d621-8c8e-dc6a1898c6fb@linaro.org Fixes: a7259df76702 ("memblock: make memblock_find_in_range method private") Signed-off-by: Mike Rapoport Tested-by: Vladimir Zapolskiy

memblock: introduce saner 'memblock_free_ptr()' interface

2021-09-14T20:23:22+00:00

The boot-time allocation interface for memblock is a mess, with 'memblock_alloc()' returning a virtual pointer, but then you are supposed to free it with 'memblock_free()' that takes a _physical_ address. Not only is that all kinds of strange and illogical, but it actually causes bugs, when people then use it like a normal allocation function, and it fails spectacularly on a NULL pointer: https://lore.kernel.org/all/20210912140820.GD25450@xsang-OptiPlex-9020/ or just random memory corruption if the debug checks don't catch it: https://lore.kernel.org/all/61ab2d0c-3313-aaab-514c-e15b7aa054a0@suse.cz/ I really don't want to apply patches that treat the symptoms, when the fundamental cause is this horribly confusing interface. I started out looking at just automating a sane replacement sequence, but because of this mix or virtual and physical addresses, and because people have used the "__pa()" macro that can take either a regular kernel pointer, or just the raw "unsigned long" address, it's all quite messy. So this just introduces a new saner interface for freeing a virtual address that was allocated using 'memblock_alloc()', and that was kept as a regular kernel pointer. And then it converts a couple of users that are obvious and easy to test, including the 'xbc_nodes' case in lib/bootconfig.c that caused problems. Reported-by: kernel test robot Fixes: 40caa127f3c7 ("init: bootconfig: Remove all bootconfig data when the init memory is removed") Cc: Steven Rostedt Cc: Mike Rapoport Cc: Andrew Morton Cc: Ingo Molnar Cc: Masami Hiramatsu Cc: Vlastimil Babka Signed-off-by: Linus Torvalds

Merge branch 'akpm' (patches from Andrew)

2021-09-03T17:08:28+00:00

Merge misc updates from Andrew Morton: "173 patches. Subsystems affected by this series: ia64, ocfs2, block, and mm (debug, pagecache, gup, swap, shmem, memcg, selftests, pagemap, mremap, bootmem, sparsemem, vmalloc, kasan, pagealloc, memory-failure, hugetlb, userfaultfd, vmscan, compaction, mempolicy, memblock, oom-kill, migration, ksm, percpu, vmstat, and madvise)" * emailed patches from Andrew Morton : (173 commits) mm/madvise: add MADV_WILLNEED to process_madvise() mm/vmstat: remove unneeded return value mm/vmstat: simplify the array size calculation mm/vmstat: correct some wrong comments mm/percpu,c: remove obsolete comments of pcpu_chunk_populated() selftests: vm: add COW time test for KSM pages selftests: vm: add KSM merging time test mm: KSM: fix data type selftests: vm: add KSM merging across nodes test selftests: vm: add KSM zero page merging test selftests: vm: add KSM unmerge test selftests: vm: add KSM merge test mm/migrate: correct kernel-doc notation mm: wire up syscall process_mrelease mm: introduce process_mrelease system call memblock: make memblock_find_in_range method private mm/mempolicy.c: use in_task() in mempolicy_slab_node() mm/mempolicy: unify the create() func for bind/interleave/prefer-many policies mm/mempolicy: advertise new MPOL_PREFERRED_MANY mm/hugetlb: add support for mempolicy MPOL_PREFERRED_MANY ...