summaryrefslogtreecommitdiffstats
path: root/tools/testing/memblock/internal.h
Commit message (Collapse)AuthorAgeFilesLines
* Revert "mm: Always release pages to the buddy allocator in ↵Aaron Thompson2023-02-221-4/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | memblock_free_late()." 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 <TASK> __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 </TASK> 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 <dev@aaront.org> Link: https://lore.kernel.org/r/20230207082151.1303-1-dev@aaront.org Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* mm: Always release pages to the buddy allocator in memblock_free_late().Aaron Thompson2023-01-181-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 115d9d77bb0f9152c60b6e8646369fa7f6167593 upstream. 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 <dev@aaront.org> Link: https://lore.kernel.org/r/01010185892de53e-e379acfb-7044-4b24-b30a-e2657c1ba989-000000@us-west-2.amazonses.com Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* memblock tests: fix compilation errorsLiu Xinpeng2022-07-291-0/+4
| | | | | | | | | | | | | | | | | Do 'make -C tools/testing/memblock', get the following errors: memblock.o: In function `memblock_find_in_range.constprop.9': memblock.c:(.text+0x4651): undefined reference to `pr_warn_ratelimited' memblock.o: In function `memblock_mark_mirror': memblock.c:(.text+0x7171): undefined reference to `mirrored_kernelcore' Fixes: 902c2d91582c ("memblock: Disable mirror feature if kernelcore is not specified") Fixes: 14d9a675fd0d ("mm: Ratelimited mirrored memory related warning messages") Signed-off-by: Liu Xinpeng <liuxp11@chinatelecom.cn> Tested-by: Ma Wupeng <mawupeng1@huawei.com> Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Link: https://lore.kernel.org/r/1658916453-26312-1-git-send-email-liuxp11@chinatelecom.cn
* memblock tests: set memblock_debug to enable memblock_dbg() messagesRebecca Mckeever2022-07-041-0/+7
| | | | | | | | | | If Memblock simulator was compiled with MEMBLOCK_DEBUG=1, set memblock_debug to 1 so that memblock_dbg() will print debug information when memblock functions are tested in Memblock simulator. Signed-off-by: Rebecca Mckeever <remckee0@gmail.com> Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Link: https://lore.kernel.org/r/aee4200cce1c09992ed055006a81fde1b6b5b567.1656907314.git.remckee0@gmail.com
* memblock tests: Add skeleton of the memblock simulatorKarolina Drobnik2022-02-201-0/+12
Add basic project files, together with local stubs of required headers. Update tools/include/slab.h to include definitions used by memblock. Signed-off-by: Karolina Drobnik <karolinadrobnik@gmail.com> Signed-off-by: Mike Rapoport <rppt@kernel.org> Link: https://lore.kernel.org/r/d296fceb023a04b316a31fbff9acf1e76ac684e4.1643796665.git.karolinadrobnik@gmail.com