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    Subject[PATCH v2 5/5] mm/page_alloc.c: avoid allocating highmem pages via alloc_pages_exact[_nid]
    Date
    Don't use with __GFP_HIGHMEM because page_address() cannot represent
    highmem pages without kmap(). Newly allocated pages would leak as
    page_address() will return NULL for highmem pages here. But It works
    now because the callers do not specify __GFP_HIGHMEM now.

    Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
    ---
    mm/page_alloc.c | 8 ++++----
    1 file changed, 4 insertions(+), 4 deletions(-)

    diff --git a/mm/page_alloc.c b/mm/page_alloc.c
    index 9c09dcb24149..e1d0e27d005a 100644
    --- a/mm/page_alloc.c
    +++ b/mm/page_alloc.c
    @@ -5614,8 +5614,8 @@ void *alloc_pages_exact(size_t size, gfp_t gfp_mask)
    unsigned int order = get_order(size);
    unsigned long addr;

    - if (WARN_ON_ONCE(gfp_mask & __GFP_COMP))
    - gfp_mask &= ~__GFP_COMP;
    + if (WARN_ON_ONCE(gfp_mask & (__GFP_COMP | __GFP_HIGHMEM)))
    + gfp_mask &= ~(__GFP_COMP | __GFP_HIGHMEM);

    addr = __get_free_pages(gfp_mask, order);
    return make_alloc_exact(addr, order, size);
    @@ -5639,8 +5639,8 @@ void * __meminit alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask)
    unsigned int order = get_order(size);
    struct page *p;

    - if (WARN_ON_ONCE(gfp_mask & __GFP_COMP))
    - gfp_mask &= ~__GFP_COMP;
    + if (WARN_ON_ONCE(gfp_mask & (__GFP_COMP | __GFP_HIGHMEM)))
    + gfp_mask &= ~(__GFP_COMP | __GFP_HIGHMEM);

    p = alloc_pages_node(nid, gfp_mask, order);
    if (!p)
    --
    2.23.0
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