From ccaea15296f9773abd43aaa17ee4b88848e4a505 Mon Sep 17 00:00:00 2001 From: "Aneesh Kumar K.V" Date: Fri, 31 Jul 2020 17:04:59 +0530 Subject: [PATCH] powerpc/vmemmap: Fix memory leak with vmemmap list allocation failures. If we fail to allocate vmemmap list, we don't keep track of allocated vmemmap block buf. Hence on section deactivate we skip vmemmap block buf free. This results in memory leak. Signed-off-by: Aneesh Kumar K.V Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200731113500.248306-1-aneesh.kumar@linux.ibm.com --- arch/powerpc/mm/init_64.c | 35 ++++++++++++++++++++++++++++------- 1 file changed, 28 insertions(+), 7 deletions(-) diff --git a/arch/powerpc/mm/init_64.c b/arch/powerpc/mm/init_64.c index 02e127fa5777..41b7da84030e 100644 --- a/arch/powerpc/mm/init_64.c +++ b/arch/powerpc/mm/init_64.c @@ -162,16 +162,16 @@ static __meminit struct vmemmap_backing * vmemmap_list_alloc(int node) return next++; } -static __meminit void vmemmap_list_populate(unsigned long phys, - unsigned long start, - int node) +static __meminit int vmemmap_list_populate(unsigned long phys, + unsigned long start, + int node) { struct vmemmap_backing *vmem_back; vmem_back = vmemmap_list_alloc(node); if (unlikely(!vmem_back)) { - WARN_ON(1); - return; + pr_debug("vmemap list allocation failed\n"); + return -ENOMEM; } vmem_back->phys = phys; @@ -179,6 +179,7 @@ static __meminit void vmemmap_list_populate(unsigned long phys, vmem_back->list = vmemmap_list; vmemmap_list = vmem_back; + return 0; } static bool altmap_cross_boundary(struct vmem_altmap *altmap, unsigned long start, @@ -199,6 +200,7 @@ static bool altmap_cross_boundary(struct vmem_altmap *altmap, unsigned long star int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node, struct vmem_altmap *altmap) { + bool altmap_alloc; unsigned long page_size = 1 << mmu_psize_defs[mmu_vmemmap_psize].shift; /* Align to the page size of the linear mapping. */ @@ -228,13 +230,32 @@ int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node, p = vmemmap_alloc_block_buf(page_size, node, altmap); if (!p) pr_debug("altmap block allocation failed, falling back to system memory"); + else + altmap_alloc = true; } - if (!p) + if (!p) { p = vmemmap_alloc_block_buf(page_size, node, NULL); + altmap_alloc = false; + } if (!p) return -ENOMEM; - vmemmap_list_populate(__pa(p), start, node); + if (vmemmap_list_populate(__pa(p), start, node)) { + /* + * If we don't populate vmemap list, we don't have + * the ability to free the allocated vmemmap + * pages in section_deactivate. Hence free them + * here. + */ + int nr_pfns = page_size >> PAGE_SHIFT; + unsigned long page_order = get_order(page_size); + + if (altmap_alloc) + vmem_altmap_free(altmap, nr_pfns); + else + free_pages((unsigned long)p, page_order); + return -ENOMEM; + } pr_debug(" * %016lx..%016lx allocated at %p\n", start, start + page_size, p); -- 2.11.0