Move compat_sys_migrate_pages() to mm/mempolicy.c and make it call a newly introduced helper -- kernel_migrate_pages() -- instead of the syscall. This patch is part of a series which removes in-kernel calls to syscalls. On this basis, the syscall entry path can be streamlined. For details, see http://lkml.kernel.org/r/20180325162527.GA17492@xxxxxxxxxxxxxxxxxxxxxxxxxx Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx> Cc: linux-mm@xxxxxxxxx Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Dominik Brodowski <linux@xxxxxxxxxxxxxxxxxxxx> --- kernel/compat.c | 33 --------------------------------- mm/mempolicy.c | 48 ++++++++++++++++++++++++++++++++++++++++++++---- 2 files changed, 44 insertions(+), 37 deletions(-) diff --git a/kernel/compat.c b/kernel/compat.c index 3f5fa8902e7d..51bdf1808943 100644 --- a/kernel/compat.c +++ b/kernel/compat.c @@ -508,39 +508,6 @@ COMPAT_SYSCALL_DEFINE6(move_pages, pid_t, pid, compat_ulong_t, nr_pages, } return sys_move_pages(pid, nr_pages, pages, nodes, status, flags); } - -COMPAT_SYSCALL_DEFINE4(migrate_pages, compat_pid_t, pid, - compat_ulong_t, maxnode, - const compat_ulong_t __user *, old_nodes, - const compat_ulong_t __user *, new_nodes) -{ - unsigned long __user *old = NULL; - unsigned long __user *new = NULL; - nodemask_t tmp_mask; - unsigned long nr_bits; - unsigned long size; - - nr_bits = min_t(unsigned long, maxnode - 1, MAX_NUMNODES); - size = ALIGN(nr_bits, BITS_PER_LONG) / 8; - if (old_nodes) { - if (compat_get_bitmap(nodes_addr(tmp_mask), old_nodes, nr_bits)) - return -EFAULT; - old = compat_alloc_user_space(new_nodes ? size * 2 : size); - if (new_nodes) - new = old + size / sizeof(unsigned long); - if (copy_to_user(old, nodes_addr(tmp_mask), size)) - return -EFAULT; - } - if (new_nodes) { - if (compat_get_bitmap(nodes_addr(tmp_mask), new_nodes, nr_bits)) - return -EFAULT; - if (new == NULL) - new = compat_alloc_user_space(size); - if (copy_to_user(new, nodes_addr(tmp_mask), size)) - return -EFAULT; - } - return sys_migrate_pages(pid, nr_bits + 1, old, new); -} #endif /* diff --git a/mm/mempolicy.c b/mm/mempolicy.c index d879f1d8a44a..7399ede02b5f 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -1377,9 +1377,9 @@ SYSCALL_DEFINE3(set_mempolicy, int, mode, const unsigned long __user *, nmask, return do_set_mempolicy(mode, flags, &nodes); } -SYSCALL_DEFINE4(migrate_pages, pid_t, pid, unsigned long, maxnode, - const unsigned long __user *, old_nodes, - const unsigned long __user *, new_nodes) +static int kernel_migrate_pages(pid_t pid, unsigned long maxnode, + const unsigned long __user *old_nodes, + const unsigned long __user *new_nodes) { struct mm_struct *mm = NULL; struct task_struct *task; @@ -1469,6 +1469,13 @@ SYSCALL_DEFINE4(migrate_pages, pid_t, pid, unsigned long, maxnode, } +SYSCALL_DEFINE4(migrate_pages, pid_t, pid, unsigned long, maxnode, + const unsigned long __user *, old_nodes, + const unsigned long __user *, new_nodes) +{ + return kernel_migrate_pages(pid, maxnode, old_nodes, new_nodes); +} + /* Retrieve NUMA policy */ SYSCALL_DEFINE5(get_mempolicy, int __user *, policy, @@ -1571,7 +1578,40 @@ COMPAT_SYSCALL_DEFINE6(mbind, compat_ulong_t, start, compat_ulong_t, len, return sys_mbind(start, len, mode, nm, nr_bits+1, flags); } -#endif +COMPAT_SYSCALL_DEFINE4(migrate_pages, compat_pid_t, pid, + compat_ulong_t, maxnode, + const compat_ulong_t __user *, old_nodes, + const compat_ulong_t __user *, new_nodes) +{ + unsigned long __user *old = NULL; + unsigned long __user *new = NULL; + nodemask_t tmp_mask; + unsigned long nr_bits; + unsigned long size; + + nr_bits = min_t(unsigned long, maxnode - 1, MAX_NUMNODES); + size = ALIGN(nr_bits, BITS_PER_LONG) / 8; + if (old_nodes) { + if (compat_get_bitmap(nodes_addr(tmp_mask), old_nodes, nr_bits)) + return -EFAULT; + old = compat_alloc_user_space(new_nodes ? size * 2 : size); + if (new_nodes) + new = old + size / sizeof(unsigned long); + if (copy_to_user(old, nodes_addr(tmp_mask), size)) + return -EFAULT; + } + if (new_nodes) { + if (compat_get_bitmap(nodes_addr(tmp_mask), new_nodes, nr_bits)) + return -EFAULT; + if (new == NULL) + new = compat_alloc_user_space(size); + if (copy_to_user(new, nodes_addr(tmp_mask), size)) + return -EFAULT; + } + return kernel_migrate_pages(pid, nr_bits + 1, old, new); +} + +#endif /* CONFIG_COMPAT */ struct mempolicy *__get_vma_policy(struct vm_area_struct *vma, unsigned long addr) -- 2.16.3
