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| author | Pasha Tatashin <pasha.tatashin@soleen.com> | 2025-11-01 10:23:20 -0400 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2025-11-27 14:24:32 -0800 |
| commit | f5bfd4793a933c7074b0d3748068b255d232bfa0 (patch) | |
| tree | 6bf6d16171a6e82a232996075aba42997c0a7439 /mm | |
| parent | 36f8f7ef7fd2f238922e9d217e86c69838319d8c (diff) | |
| download | tip-f5bfd4793a933c7074b0d3748068b255d232bfa0.tar.gz | |
memblock: unpreserve memory in case of error
If there is an error half way through KHO memory preservation, we should
rollback and unpreserve everything that is partially preserved.
[akpm@linux-foundation.org: s/err_no_fdt_page/err_report/ in prepare_kho_fdt(), per Mike]
Link: https://lkml.kernel.org/r/20251101142325.1326536-5-pasha.tatashin@soleen.com
Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Suggested-by: Pratyush Yadav <pratyush@kernel.org>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Pratyush Yadav <pratyush@kernel.org>
Cc: Alexander Graf <graf@amazon.com>
Cc: Changyuan Lyu <changyuanl@google.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Simon Horman <horms@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Zhu Yanjun <yanjun.zhu@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/memblock.c | 73 |
1 files changed, 58 insertions, 15 deletions
diff --git a/mm/memblock.c b/mm/memblock.c index e3bef9b35d63de..c7869860e6593e 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -2445,29 +2445,60 @@ int reserve_mem_release_by_name(const char *name) #define MEMBLOCK_KHO_NODE_COMPATIBLE "memblock-v1" #define RESERVE_MEM_KHO_NODE_COMPATIBLE "reserve-mem-v1" +static int __init reserved_mem_preserve(void) +{ + unsigned int nr_preserved = 0; + int err; + + for (unsigned int i = 0; i < reserved_mem_count; i++, nr_preserved++) { + struct reserve_mem_table *map = &reserved_mem_table[i]; + struct page *page = phys_to_page(map->start); + unsigned int nr_pages = map->size >> PAGE_SHIFT; + + err = kho_preserve_pages(page, nr_pages); + if (err) + goto err_unpreserve; + } + + return 0; + +err_unpreserve: + for (unsigned int i = 0; i < nr_preserved; i++) { + struct reserve_mem_table *map = &reserved_mem_table[i]; + struct page *page = phys_to_page(map->start); + unsigned int nr_pages = map->size >> PAGE_SHIFT; + + kho_unpreserve_pages(page, nr_pages); + } + + return err; +} + static int __init prepare_kho_fdt(void) { - int err = 0, i; struct page *fdt_page; void *fdt; + int err; fdt_page = alloc_page(GFP_KERNEL); - if (!fdt_page) - return -ENOMEM; + if (!fdt_page) { + err = -ENOMEM; + goto err_report; + } fdt = page_to_virt(fdt_page); + err = kho_preserve_pages(fdt_page, 1); + if (err) + goto err_free_fdt; err |= fdt_create(fdt, PAGE_SIZE); err |= fdt_finish_reservemap(fdt); - err |= fdt_begin_node(fdt, ""); err |= fdt_property_string(fdt, "compatible", MEMBLOCK_KHO_NODE_COMPATIBLE); - for (i = 0; i < reserved_mem_count; i++) { + + for (unsigned int i = 0; !err && i < reserved_mem_count; i++) { struct reserve_mem_table *map = &reserved_mem_table[i]; - struct page *page = phys_to_page(map->start); - unsigned int nr_pages = map->size >> PAGE_SHIFT; - err |= kho_preserve_pages(page, nr_pages); err |= fdt_begin_node(fdt, map->name); err |= fdt_property_string(fdt, "compatible", RESERVE_MEM_KHO_NODE_COMPATIBLE); err |= fdt_property(fdt, "start", &map->start, sizeof(map->start)); @@ -2477,15 +2508,27 @@ static int __init prepare_kho_fdt(void) err |= fdt_end_node(fdt); err |= fdt_finish(fdt); - err |= kho_preserve_folio(page_folio(fdt_page)); + if (err) + goto err_unpreserve_fdt; - if (!err) - err = kho_add_subtree(MEMBLOCK_KHO_FDT, fdt); + err = kho_add_subtree(MEMBLOCK_KHO_FDT, fdt); + if (err) + goto err_unpreserve_fdt; - if (err) { - pr_err("failed to prepare memblock FDT for KHO: %d\n", err); - put_page(fdt_page); - } + err = reserved_mem_preserve(); + if (err) + goto err_remove_subtree; + + return 0; + +err_remove_subtree: + kho_remove_subtree(fdt); +err_unpreserve_fdt: + kho_unpreserve_pages(fdt_page, 1); +err_free_fdt: + put_page(fdt_page); +err_report: + pr_err("failed to prepare memblock FDT for KHO: %d\n", err); return err; } |