Messages in this thread Patch in this message | | | Date | Fri, 15 Apr 2022 13:41:34 +0800 | Subject | Re: [PATCH v3 1/4] hugetlb: Fix wrong use of nr_online_nodes | From | Kefeng Wang <> |
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On 2022/4/15 10:09, Davidlohr Bueso wrote: > On Wed, 13 Apr 2022, Peng Liu wrote: > >> Certain systems are designed to have sparse/discontiguous nodes. In >> this case, nr_online_nodes can not be used to walk through numa node. >> Also, a valid node may be greater than nr_online_nodes. >> >> However, in hugetlb, it is assumed that nodes are contiguous. Recheck >> all the places that use nr_online_nodes, and repair them one by one. >> >> Suggested-by: David Hildenbrand <david@redhat.com> >> Fixes: 4178158ef8ca ("hugetlbfs: fix issue of preallocation of >> gigantic pages can't work") >> Fixes: b5389086ad7b ("hugetlbfs: extend the definition of hugepages >> parameter to support node allocation") >> Fixes: e79ce9832316 ("hugetlbfs: fix a truncation issue in hugepages >> parameter") >> Fixes: f9317f77a6e0 ("hugetlb: clean up potential spectre issue >> warnings") >> Signed-off-by: Peng Liu <liupeng256@huawei.com> >> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> >> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> > > Reviewed-by: Davidlohr Bueso <dave@stgolabs.net> > > ... but > >> --- >> mm/hugetlb.c | 12 ++++++------ >> 1 file changed, 6 insertions(+), 6 deletions(-) >> >> diff --git a/mm/hugetlb.c b/mm/hugetlb.c >> index b34f50156f7e..5b5a2a5a742f 100644 >> --- a/mm/hugetlb.c >> +++ b/mm/hugetlb.c >> @@ -2979,7 +2979,7 @@ int __alloc_bootmem_huge_page(struct hstate *h, >> int nid) >> struct huge_bootmem_page *m = NULL; /* initialize for clang */ >> int nr_nodes, node; >> >> - if (nid != NUMA_NO_NODE && nid >= nr_online_nodes) >> + if (nid != NUMA_NO_NODE && !node_online(nid)) > > afaict null_blk could also use this, actually the whole thing wants a > helper - node_valid()? > This one should be unnecessary, and this patch looks has a bug,
if a very nid passed to node_online(), it may crash, could you re-check it,
see my changes below,
1) add tmp check against MAX_NUMNODES before node_online() check,
and move it after get tmp in hugepages_setup() , this could cover both per-node alloc and normal alloc
2) due to for_each_online_node() usage, we can drop additional check of nid in __alloc_bootmem_huge_page()
$ git diff diff --git a/mm/hugetlb.c b/mm/hugetlb.c index fb5a549169ce..5a3ddec181a0 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -2986,8 +2986,6 @@ int __alloc_bootmem_huge_page(struct hstate *h, int nid) struct huge_bootmem_page *m = NULL; /* initialize for clang */ int nr_nodes, node;
- if (nid != NUMA_NO_NODE && nid >= nr_online_nodes) - return 0; /* do node specific alloc */ if (nid != NUMA_NO_NODE) { m = memblock_alloc_try_nid_raw(huge_page_size(h), huge_page_size(h), @@ -3095,7 +3093,7 @@ static void __init hugetlb_hstate_alloc_pages(struct hstate *h) }
/* do node specific alloc */ - for (i = 0; i < nr_online_nodes; i++) { + for_each_online_node(i) { if (h->max_huge_pages_node[i] > 0) { hugetlb_hstate_alloc_pages_onenode(h, i); node_specific_alloc = true; @@ -4059,7 +4057,7 @@ static int __init hugetlb_init(void) default_hstate.max_huge_pages = default_hstate_max_huge_pages;
- for (i = 0; i < nr_online_nodes; i++) + for_each_online_node(i) default_hstate.max_huge_pages_node[i] = default_hugepages_in_node[i]; } @@ -4168,15 +4166,15 @@ static int __init hugepages_setup(char *s) count = 0; if (sscanf(p, "%lu%n", &tmp, &count) != 1) goto invalid; + if (tmp > MAX_NUMNODES || !node_online(tmp)) + goto invalid; /* Parameter is node format */ if (p[count] == ':') { if (!hugetlb_node_alloc_supported()) { pr_warn("HugeTLB: architecture can't support node specific alloc, ignoring!\n"); return 0; } - if (tmp >= nr_online_nodes) - goto invalid; - node = array_index_nospec(tmp, nr_online_nodes); + node = array_index_nospec(tmp, MAX_NUMNODES); p += count + 1; /* Parse hugepages */ if (sscanf(p, "%lu%n", &tmp, &count) != 1) @@ -4304,7 +4302,7 @@ static int __init default_hugepagesz_setup(char *s) */ if (default_hstate_max_huge_pages) { default_hstate.max_huge_pages = default_hstate_max_huge_pages; - for (i = 0; i < nr_online_nodes; i++) + for_each_online_node(i) default_hstate.max_huge_pages_node[i] = default_hugepages_in_node[i]; if (hstate_is_gigantic(&default_hstate))
> .
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