From: Wenchao Hao <haowenchao22@xxxxxxxxx> Subject: mm/mempolicy.c: check parameters first in kernel_get_mempolicy Previous implementatoin calls untagged_addr() before error check, while if the error check failed and return EINVAL, the untagged_addr() call is just useless work. Link: http://lkml.kernel.org/r/20200801090825.5597-1-haowenchao22@xxxxxxxxx Signed-off-by: Wenchao Hao <haowenchao22@xxxxxxxxx> Reviewed-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/mempolicy.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/mm/mempolicy.c~mm-mempolicy-check-parameters-first-in-kernel_get_mempolicy +++ a/mm/mempolicy.c @@ -1632,11 +1632,11 @@ static int kernel_get_mempolicy(int __us int pval; nodemask_t nodes; - addr = untagged_addr(addr); - if (nmask != NULL && maxnode < nr_node_ids) return -EINVAL; + addr = untagged_addr(addr); + err = do_get_mempolicy(&pval, &nodes, addr, flags); if (err) _
