kernel/linux.git/mm/memblock.c, branch v5.10.264

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

2023-02-22T11:55:56+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().

2023-01-18T10:44:59+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

2022-03-02T10:42:57+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: ensure there is no overflow in memblock_overlaps_region()

2021-12-17T09:14:42+00:00

[ Upstream commit 023accf5cdc1e504a9b04187ec23ff156fe53d90 ] There maybe an overflow in memblock_overlaps_region() if it is called with base and size such that base + size > PHYS_ADDR_MAX Make sure that memblock_overlaps_region() caps the size to prevent such overflow and remove now duplicated call to memblock_cap_size() from memblock_is_region_reserved(). Signed-off-by: Mike Rapoport Tested-by: Tony Lindgren Link: https://lore.kernel.org/lkml/20210630071211.21011-1-rppt@kernel.org/ Signed-off-by: Mark-PK Tsai Signed-off-by: Greg Kroah-Hartman

memblock: make for_each_mem_range() traverse MEMBLOCK_HOTPLUG regions

2021-07-28T12:35:46+00:00

commit 79e482e9c3ae86e849c701c846592e72baddda5a upstream. Commit b10d6bca8720 ("arch, drivers: replace for_each_membock() with for_each_mem_range()") didn't take into account that when there is movable_node parameter in the kernel command line, for_each_mem_range() would skip ranges marked with MEMBLOCK_HOTPLUG. The page table setup code in POWER uses for_each_mem_range() to create the linear mapping of the physical memory and since the regions marked as MEMORY_HOTPLUG are skipped, they never make it to the linear map. A later access to the memory in those ranges will fail: BUG: Unable to handle kernel data access on write at 0xc000000400000000 Faulting instruction address: 0xc00000000008a3c0 Oops: Kernel access of bad area, sig: 11 [#1] LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA pSeries Modules linked in: CPU: 0 PID: 53 Comm: kworker/u2:0 Not tainted 5.13.0 #7 NIP: c00000000008a3c0 LR: c0000000003c1ed8 CTR: 0000000000000040 REGS: c000000008a57770 TRAP: 0300 Not tainted (5.13.0) MSR: 8000000002009033 CR: 84222202 XER: 20040000 CFAR: c0000000003c1ed4 DAR: c000000400000000 DSISR: 42000000 IRQMASK: 0 GPR00: c0000000003c1ed8 c000000008a57a10 c0000000019da700 c000000400000000 GPR04: 0000000000000280 0000000000000180 0000000000000400 0000000000000200 GPR08: 0000000000000100 0000000000000080 0000000000000040 0000000000000300 GPR12: 0000000000000380 c000000001bc0000 c0000000001660c8 c000000006337e00 GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 GPR20: 0000000040000000 0000000020000000 c000000001a81990 c000000008c30000 GPR24: c000000008c20000 c000000001a81998 000fffffffff0000 c000000001a819a0 GPR28: c000000001a81908 c00c000001000000 c000000008c40000 c000000008a64680 NIP clear_user_page+0x50/0x80 LR __handle_mm_fault+0xc88/0x1910 Call Trace: __handle_mm_fault+0xc44/0x1910 (unreliable) handle_mm_fault+0x130/0x2a0 __get_user_pages+0x248/0x610 __get_user_pages_remote+0x12c/0x3e0 get_arg_page+0x54/0xf0 copy_string_kernel+0x11c/0x210 kernel_execve+0x16c/0x220 call_usermodehelper_exec_async+0x1b0/0x2f0 ret_from_kernel_thread+0x5c/0x70 Instruction dump: 79280fa4 79271764 79261f24 794ae8e2 7ca94214 7d683a14 7c893a14 7d893050 7d4903a6 60000000 60000000 60000000 <7c001fec> 7c091fec 7c081fec 7c051fec ---[ end trace 490b8c67e6075e09 ]--- Making for_each_mem_range() include MEMBLOCK_HOTPLUG regions in the traversal fixes this issue. Link: https://bugzilla.redhat.com/show_bug.cgi?id=1976100 Link: https://lkml.kernel.org/r/20210712071132.20902-1-rppt@kernel.org Fixes: b10d6bca8720 ("arch, drivers: replace for_each_membock() with for_each_mem_range()") Signed-off-by: Mike Rapoport Tested-by: Greg Kurz Reviewed-by: David Hildenbrand Cc: [5.10+] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

memblock: do not start bottom-up allocations with kernel_end

2021-02-10T08:29:15+00:00

[ Upstream commit 2dcb3964544177c51853a210b6ad400de78ef17d ] With kaslr the kernel image is placed at a random place, so starting the bottom-up allocation with the kernel_end can result in an allocation failure and a warning like this one: hugetlb_cma: reserve 2048 MiB, up to 2048 MiB per node ------------[ cut here ]------------ memblock: bottom-up allocation failed, memory hotremove may be affected WARNING: CPU: 0 PID: 0 at mm/memblock.c:332 memblock_find_in_range_node+0x178/0x25a Modules linked in: CPU: 0 PID: 0 Comm: swapper Not tainted 5.10.0+ #1169 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-1.fc33 04/01/2014 RIP: 0010:memblock_find_in_range_node+0x178/0x25a Code: e9 6d ff ff ff 48 85 c0 0f 85 da 00 00 00 80 3d 9b 35 df 00 00 75 15 48 c7 c7 c0 75 59 88 c6 05 8b 35 df 00 01 e8 25 8a fa ff <0f> 0b 48 c7 44 24 20 ff ff ff ff 44 89 e6 44 89 ea 48 c7 c1 70 5c RSP: 0000:ffffffff88803d18 EFLAGS: 00010086 ORIG_RAX: 0000000000000000 RAX: 0000000000000000 RBX: 0000000240000000 RCX: 00000000ffffdfff RDX: 00000000ffffdfff RSI: 00000000ffffffea RDI: 0000000000000046 RBP: 0000000100000000 R08: ffffffff88922788 R09: 0000000000009ffb R10: 00000000ffffe000 R11: 3fffffffffffffff R12: 0000000000000000 R13: 0000000000000000 R14: 0000000080000000 R15: 00000001fb42c000 FS: 0000000000000000(0000) GS:ffffffff88f71000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffa080fb401000 CR3: 00000001fa80a000 CR4: 00000000000406b0 Call Trace: memblock_alloc_range_nid+0x8d/0x11e cma_declare_contiguous_nid+0x2c4/0x38c hugetlb_cma_reserve+0xdc/0x128 flush_tlb_one_kernel+0xc/0x20 native_set_fixmap+0x82/0xd0 flat_get_apic_id+0x5/0x10 register_lapic_address+0x8e/0x97 setup_arch+0x8a5/0xc3f start_kernel+0x66/0x547 load_ucode_bsp+0x4c/0xcd secondary_startup_64_no_verify+0xb0/0xbb random: get_random_bytes called from __warn+0xab/0x110 with crng_init=0 ---[ end trace f151227d0b39be70 ]--- At the same time, the kernel image is protected with memblock_reserve(), so we can just start searching at PAGE_SIZE. In this case the bottom-up allocation has the same chances to success as a top-down allocation, so there is no reason to fallback in the case of a failure. All together it simplifies the logic. Link: https://lkml.kernel.org/r/20201217201214.3414100-2-guro@fb.com Fixes: 8fabc623238e ("powerpc: Ensure that swiotlb buffer is allocated from low memory") Signed-off-by: Roman Gushchin Reviewed-by: Mike Rapoport Cc: Joonsoo Kim Cc: Michal Hocko Cc: Rik van Riel Cc: Wonhyuk Yang Cc: Thiago Jung Bauermann Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin

memblock: get rid of a :c:type leftover

2020-10-15T05:49:46+00:00

chanseset b3a7bb1851c8 ("docs: get rid of :c:type explicit declarations for structs") removed several :c:type: markups, except by one. Now, Sphinx 3.x complains about it: .../Documentation/core-api/boot-time-mm:26: ../mm/memblock.c:51: WARNING: Unparseable C cross-reference: 'struct\nmemblock_type' Invalid C declaration: Expected identifier in nested name, got keyword: struct [error at 6] struct memblock_type ------^ As, on Sphinx 3.x, the right markup is c:struct:`foo`. So, let's remove it, relying on automarkup.py to convert it. Reviewed-by: Mike Rapoport Signed-off-by: Mauro Carvalho Chehab

docs: get rid of :c:type explicit declarations for structs

2020-10-15T05:49:40+00:00

The :c:type:`foo` only works properly with structs before Sphinx 3.x. On Sphinx 3.x, structs should now be declared using the .. c:struct, and referenced via :c:struct tag. As we now have the automarkup.py macro, that automatically convert: struct foo into cross-references, let's get rid of that, solving several warnings when building docs with Sphinx 3.x. Reviewed-by: André Almeida # blk-mq.rst Reviewed-by: Takashi Iwai # sound Reviewed-by: Mike Rapoport Reviewed-by: Greg Kroah-Hartman Signed-off-by: Mauro Carvalho Chehab

memblock: use separate iterators for memory and reserved regions

2020-10-14T01:38:35+00:00

for_each_memblock() is used to iterate over memblock.memory in a few places that use data from memblock_region rather than the memory ranges. Introduce separate for_each_mem_region() and for_each_reserved_mem_region() to improve encapsulation of memblock internals from its users. Signed-off-by: Mike Rapoport Signed-off-by: Andrew Morton Reviewed-by: Baoquan He Acked-by: Ingo Molnar [x86] Acked-by: Thomas Bogendoerfer [MIPS] Acked-by: Miguel Ojeda [.clang-format] Cc: Andy Lutomirski Cc: Benjamin Herrenschmidt Cc: Borislav Petkov Cc: Catalin Marinas Cc: Christoph Hellwig Cc: Daniel Axtens Cc: Dave Hansen Cc: Emil Renner Berthing Cc: Hari Bathini Cc: Ingo Molnar Cc: Jonathan Cameron Cc: Marek Szyprowski Cc: Max Filippov Cc: Michael Ellerman Cc: Michal Simek Cc: Palmer Dabbelt Cc: Paul Mackerras Cc: Paul Walmsley Cc: Peter Zijlstra Cc: Russell King Cc: Stafford Horne Cc: Thomas Gleixner Cc: Will Deacon Cc: Yoshinori Sato Link: https://lkml.kernel.org/r/20200818151634.14343-18-rppt@kernel.org Signed-off-by: Linus Torvalds

memblock: implement for_each_reserved_mem_region() using __next_mem_region()

2020-10-14T01:38:35+00:00

Iteration over memblock.reserved with for_each_reserved_mem_region() used __next_reserved_mem_region() that implemented a subset of __next_mem_region(). Use __for_each_mem_range() and, essentially, __next_mem_region() with appropriate parameters to reduce code duplication. While on it, rename for_each_reserved_mem_region() to for_each_reserved_mem_range() for consistency. Signed-off-by: Mike Rapoport Signed-off-by: Andrew Morton Acked-by: Miguel Ojeda [.clang-format] Cc: Andy Lutomirski Cc: Baoquan He Cc: Benjamin Herrenschmidt Cc: Borislav Petkov Cc: Catalin Marinas Cc: Christoph Hellwig Cc: Daniel Axtens Cc: Dave Hansen Cc: Emil Renner Berthing Cc: Hari Bathini Cc: Ingo Molnar Cc: Ingo Molnar Cc: Jonathan Cameron Cc: Marek Szyprowski Cc: Max Filippov Cc: Michael Ellerman Cc: Michal Simek Cc: Palmer Dabbelt Cc: Paul Mackerras Cc: Paul Walmsley Cc: Peter Zijlstra Cc: Russell King Cc: Stafford Horne Cc: Thomas Bogendoerfer Cc: Thomas Gleixner Cc: Will Deacon Cc: Yoshinori Sato Link: https://lkml.kernel.org/r/20200818151634.14343-17-rppt@kernel.org Signed-off-by: Linus Torvalds