kernel/linux.git/mm/memblock.c, branch v6.12.80

memblock: Accept allocated memory before use in memblock_double_array()

2025-05-18T06:24:54+00:00

commit da8bf5daa5e55a6af2b285ecda460d6454712ff4 upstream. When increasing the array size in memblock_double_array() and the slab is not yet available, a call to memblock_find_in_range() is used to reserve/allocate memory. However, the range returned may not have been accepted, which can result in a crash when booting an SNP guest: RIP: 0010:memcpy_orig+0x68/0x130 Code: ... RSP: 0000:ffffffff9cc03ce8 EFLAGS: 00010006 RAX: ff11001ff83e5000 RBX: 0000000000000000 RCX: fffffffffffff000 RDX: 0000000000000bc0 RSI: ffffffff9dba8860 RDI: ff11001ff83e5c00 RBP: 0000000000002000 R08: 0000000000000000 R09: 0000000000002000 R10: 000000207fffe000 R11: 0000040000000000 R12: ffffffff9d06ef78 R13: ff11001ff83e5000 R14: ffffffff9dba7c60 R15: 0000000000000c00 memblock_double_array+0xff/0x310 memblock_add_range+0x1fb/0x2f0 memblock_reserve+0x4f/0xa0 memblock_alloc_range_nid+0xac/0x130 memblock_alloc_internal+0x53/0xc0 memblock_alloc_try_nid+0x3d/0xa0 swiotlb_init_remap+0x149/0x2f0 mem_init+0xb/0xb0 mm_core_init+0x8f/0x350 start_kernel+0x17e/0x5d0 x86_64_start_reservations+0x14/0x30 x86_64_start_kernel+0x92/0xa0 secondary_startup_64_no_verify+0x194/0x19b Mitigate this by calling accept_memory() on the memory range returned before the slab is available. Prior to v6.12, the accept_memory() interface used a 'start' and 'end' parameter instead of 'start' and 'size', therefore the accept_memory() call must be adjusted to specify 'start + size' for 'end' when applying to kernels prior to v6.12. Cc: stable@vger.kernel.org # see patch description, needs adjustments for <= 6.11 Fixes: dcdfdd40fa82 ("mm: Add support for unaccepted memory") Signed-off-by: Tom Lendacky Link: https://lore.kernel.org/r/da1ac73bf4ded761e21b4e4bb5178382a580cd73.1746725050.git.thomas.lendacky@amd.com Signed-off-by: Mike Rapoport (Microsoft) Signed-off-by: Greg Kroah-Hartman

mm/memblock: repeat setting reserved region nid if array is doubled

2025-05-09T07:50:32+00:00

commit eac8ea8736ccc09513152d970eb2a42ed78e87e8 upstream. Commit 61167ad5fecd ("mm: pass nid to reserve_bootmem_region()") introduce a way to set nid to all reserved region. But there is a corner case it will leave some region with invalid nid. When memblock_set_node() doubles the array of memblock.reserved, it may lead to a new reserved region before current position. The new region will be left with an invalid node id. Repeat the process when detecting it. Fixes: 61167ad5fecd ("mm: pass nid to reserve_bootmem_region()") Signed-off-by: Wei Yang CC: Mike Rapoport CC: Yajun Deng CC: stable@vger.kernel.org Link: https://lore.kernel.org/r/20250318071948.23854-3-richard.weiyang@gmail.com Signed-off-by: Mike Rapoport (Microsoft) Signed-off-by: Greg Kroah-Hartman

mm/memblock: pass size instead of end to memblock_set_node()

2025-05-09T07:50:32+00:00

commit 06eaa824fd239edd1eab2754f29b2d03da313003 upstream. The second parameter of memblock_set_node() is size instead of end. Since it iterates from lower address to higher address, finally the node id is correct. But during the process, some of them are wrong. Pass size instead of end. Fixes: 61167ad5fecd ("mm: pass nid to reserve_bootmem_region()") Signed-off-by: Wei Yang CC: Mike Rapoport CC: Yajun Deng CC: stable@vger.kernel.org Reviewed-by: Anshuman Khandual Link: https://lore.kernel.org/r/20250318071948.23854-2-richard.weiyang@gmail.com Signed-off-by: Mike Rapoport (Microsoft) Signed-off-by: Greg Kroah-Hartman

memblock: allow zero threshold in validate_numa_converage()

2024-12-14T19:03:34+00:00

commit 9cdc6423acb49055efb444ecd895d853a70ef931 upstream. Currently memblock validate_numa_converage() returns false negative when threshold set to zero. Make the check if the memory size with invalid node ID is greater than the threshold exclusive to fix that. Link: https://lore.kernel.org/all/Z0mIDBD4KLyxyOCm@kernel.org/ Signed-off-by: Mike Rapoport (Microsoft) Signed-off-by: Greg Kroah-Hartman

Merge tag 'memblock-v6.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock

2024-09-25T18:35:19+00:00

Pull memblock updates from Mike Rapoport: - new memblock_estimated_nr_free_pages() helper to replace totalram_pages() which is less accurate when CONFIG_DEFERRED_STRUCT_PAGE_INIT is set - fixes for memblock tests * tag 'memblock-v6.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock: s390/mm: get estimated free pages by memblock api kernel/fork.c: get estimated free pages by memblock api mm/memblock: introduce a new helper memblock_estimated_nr_free_pages() memblock test: fix implicit declaration of function 'strscpy' memblock test: fix implicit declaration of function 'isspace' memblock test: fix implicit declaration of function 'memparse' memblock test: add the definition of __setup() memblock test: fix implicit declaration of function 'virt_to_phys' tools/testing: abstract two init.h into common include directory memblock tests: include export.h in linkage.h as kernel dose memblock tests: include memory_hotplug.h in mmzone.h as kernel dose

mm: rework accept memory helpers

2024-09-02T03:26:07+00:00

Make accept_memory() and range_contains_unaccepted_memory() take 'start' and 'size' arguments instead of 'start' and 'end'. Remove accept_page(), replacing it with direct calls to accept_memory(). The accept_page() name is going to be used for a different function. Link: https://lkml.kernel.org/r/20240809114854.3745464-6-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov Suggested-by: David Hildenbrand Cc: Borislav Petkov Cc: Johannes Weiner Cc: Matthew Wilcox Cc: Mel Gorman Cc: Mike Rapoport (Microsoft) Cc: Tom Lendacky Cc: Vlastimil Babka Signed-off-by: Andrew Morton

mm/memblock: introduce a new helper memblock_estimated_nr_free_pages()

2024-08-11T16:18:52+00:00

During bootup, system may need the number of free pages in the whole system to do some calculation before all pages are freed to buddy system. Usually this number is get from totalram_pages(). Since we plan to move the free pages accounting in __free_pages_core(), this value may not represent total free pages at the early stage, especially when CONFIG_DEFERRED_STRUCT_PAGE_INIT is enabled. Instead of using raw memblock api, let's introduce a new helper for user to get the estimated number of free pages from memblock point of view. Signed-off-by: Wei Yang CC: David Hildenbrand Reviewed-by: David Hildenbrand Link: https://lore.kernel.org/r/20240808001415.6298-1-richard.weiyang@gmail.com Signed-off-by: Mike Rapoport (Microsoft)

Merge tag 'memblock-v6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock

2024-07-18T21:48:11+00:00

Pull memblock updates from Mike Rapoport: - 'reserve_mem' command line parameter to allow creation of named memory reservation at boot time. The driving use-case is to improve the ability of pstore to retain ramoops data across reboots. - cleanups and small improvements in memblock and mm_init - new tests cases in memblock test suite * tag 'memblock-v6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock: memblock tests: fix implicit declaration of function 'numa_valid_node' memblock: Move late alloc warning down to phys alloc pstore/ramoops: Add ramoops.mem_name= command line option mm/memblock: Add "reserve_mem" to reserved named memory at boot up mm/mm_init.c: don't initialize page->lru again mm/mm_init.c: not always search next deferred_init_pfn from very beginning mm/mm_init.c: use deferred_init_mem_pfn_range_in_zone() to decide loop condition mm/mm_init.c: get the highest zone directly mm/mm_init.c: move nr_initialised reset down a bit mm/memblock: fix a typo in description of for_each_mem_region() mm/mm_init.c: use memblock_region_memory_base_pfn() to get startpfn mm/memblock: use PAGE_ALIGN_DOWN to get pgend in free_memmap mm/memblock: return true directly on finding overlap region memblock tests: add memblock_overlaps_region_checks mm/memblock: fix comment for memblock_isolate_range() memblock tests: add memblock_reserve_many_may_conflict_check() memblock tests: add memblock_reserve_all_locations_check() mm/memblock: remove empty dummy entry

memblock: Move late alloc warning down to phys alloc

2024-06-19T15:05:25+00:00

If a driver/subsystem tries to do an allocation after the memblock allocations have been freed and the memory handed to the buddy allocator, it will not actually be legal to use that allocation: the buddy allocator owns the memory. Currently this mis-use is handled by the memblock function which does allocations and returns virtual addresses by printing a warning and doing a kmalloc instead. However the physical allocation function does not to do this check - callers of the physical alloc function are unprotected against mis-use. Improve the error catching here by moving the check into the physical allocation function which is used by the virtual addr allocation function. Signed-off-by: James Gowans Cc: Mike Rapoport Cc: Andrew Morton Cc: Alex Graf Link: https://lore.kernel.org/r/20240619095555.85980-1-jgowans@amazon.com Signed-off-by: Mike Rapoport (IBM)

mm/memblock: Add "reserve_mem" to reserved named memory at boot up

2024-06-19T07:59:49+00:00

In order to allow for requesting a memory region that can be used for things like pstore on multiple machines where the memory layout is not the same, add a new option to the kernel command line called "reserve_mem". The format is: reserve_mem=nn:align:name Where it will find nn amount of memory at the given alignment of align. The name field is to allow another subsystem to retrieve where the memory was found. For example: reserve_mem=12M:4096:oops ramoops.mem_name=oops Where ramoops.mem_name will tell ramoops that memory was reserved for it via the reserve_mem option and it can find it by calling: if (reserve_mem_find_by_name("oops", &start, &size)) { // start holds the start address and size holds the size given This is typically used for systems that do not wipe the RAM, and this command line will try to reserve the same physical memory on soft reboots. Note, it is not guaranteed to be the same location. For example, if KASLR places the kernel at the location of where the RAM reservation was from a previous boot, the new reservation will be at a different location. Any subsystem using this feature must add a way to verify that the contents of the physical memory is from a previous boot, as there may be cases where the memory will not be located at the same location. Not all systems may work either. There could be bit flips if the reboot goes through the BIOS. Using kexec to reboot the machine is likely to have better results in such cases. Link: https://lore.kernel.org/all/ZjJVnZUX3NZiGW6q@kernel.org/ Suggested-by: Mike Rapoport Tested-by: Guilherme G. Piccoli Signed-off-by: Steven Rostedt (Google) Link: https://lore.kernel.org/r/20240613155527.437020271@goodmis.org Signed-off-by: Mike Rapoport (IBM)