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| author | Qiang Liu <liuqiang@kylinos.cn> | 2026-05-21 10:18:58 +0800 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2026-06-08 18:21:32 -0700 |
| commit | 8198657c74170ea78808d1f1d886c7d35fd3694e (patch) | |
| tree | 4e2749dfe3a378ef6cd2a3de64e1c49c7a2430ed /lib | |
| parent | 32a2b73ec232b284b029d34bcfaa9a7f424151d2 (diff) | |
| download | lwn-8198657c74170ea78808d1f1d886c7d35fd3694e.tar.gz lwn-8198657c74170ea78808d1f1d886c7d35fd3694e.zip | |
lib/test_hmm: check alloc_page_vma() return value and handle OOM
Check alloc_page_vma() return status for page allocation failures, free
allocated pages and return VM_FAULT_OOM on error.
Handle return codes of dmirror_devmem_fault_alloc_and_copy(), call
migrate_vma_finalize() to remove migration entries from
migrate_vma_setup().
Link: https://lore.kernel.org/20260521021858.21511-1-liuqiangneo@163.com
Signed-off-by: Qiang Liu <liuqiang@kylinos.cn>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Leon Romanovsky <leon@kernel.org>
[akpm@linux-foundation.org: fix dmirror_devmem_fault_alloc_and_copy() retval handling]
Link: https://lore.kernel.org/oe-kbuild-all/202606011329.zWs2BKy4-lkp@intel.com/
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/test_hmm.c | 29 |
1 files changed, 27 insertions, 2 deletions
diff --git a/lib/test_hmm.c b/lib/test_hmm.c index 35f774ed2d99..9c59d1ceb5b5 100644 --- a/lib/test_hmm.c +++ b/lib/test_hmm.c @@ -1063,6 +1063,25 @@ static vm_fault_t dmirror_devmem_fault_alloc_and_copy(struct migrate_vma *args, /* Try with smaller pages if large allocation fails */ if (!dpage && order) { dpage = alloc_page_vma(GFP_HIGHUSER_MOVABLE, args->vma, addr); + if (!dpage) { + /* Unlock and free pages already allocated. */ + while (i > 0) { + struct page *fpage; + + fpage = migrate_pfn_to_page(dst[--i]); + unlock_page(fpage); + __free_page(fpage); + } + /* Clear remaining dst entries to avoid + * migrate_vma_pages/finalize() using + * uninitialized values. + */ + while (i < (1 << order)) { + dst[i] = 0; + i++; + } + return VM_FAULT_OOM; + } lock_page(dpage); dst[i] = migrate_pfn(page_to_pfn(dpage)); dst_page = pfn_to_page(page_to_pfn(dpage)); @@ -1148,7 +1167,11 @@ static int dmirror_migrate_to_system(struct dmirror *dmirror, goto out; pr_debug("Migrating from device mem to sys mem\n"); - dmirror_devmem_fault_alloc_and_copy(&args, dmirror); + if (dmirror_devmem_fault_alloc_and_copy(&args, dmirror)) { + migrate_vma_finalize(&args); + ret = -ENOMEM; + goto out; + } migrate_vma_pages(&args); cmd->cpages += dmirror_successful_migrated_pages(&args); @@ -1689,8 +1712,10 @@ static vm_fault_t dmirror_devmem_fault(struct vm_fault *vmf) } ret = dmirror_devmem_fault_alloc_and_copy(&args, dmirror); - if (ret) + if (ret) { + migrate_vma_finalize(&args); goto err; + } migrate_vma_pages(&args); /* * No device finalize step is needed since |