From: Qiang Liu 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(). Signed-off-by: Qiang Liu --- v3: - Clear dst[i] to avoid migration in subsequent migrate_vma_pages/finalize() calls - Handle return codes of dmirror_devmem_fault_alloc_and_copy() - call migrate_vma_finalize() to remove migration entries from migrate_vma_setup(). v2: - Add unlock and free allocated pages before return. - https://lore.kernel.org/all/20260514032345.32256-1-liuqiangneo@163.com/ --- lib/test_hmm.c | 29 +++++++++++++++++++++++++++-- 1 file changed, 27 insertions(+), 2 deletions(-) diff --git a/lib/test_hmm.c b/lib/test_hmm.c index 5430ef97bbe0..2d75a49e8e7f 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); + ret = dmirror_devmem_fault_alloc_and_copy(&args, dmirror); + if (ret) { + migrate_vma_finalize(&args); + goto out; + } migrate_vma_pages(&args); cmd->cpages += dmirror_successful_migrated_pages(&args); @@ -1685,8 +1708,10 @@ 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 -- 2.43.0