Move compat_sys_move_pages() to mm/migrate.c and make it call a newly introduced helper -- kernel_move_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.ga17...@light.dominikbrodowski.net Cc: Al Viro <v...@zeniv.linux.org.uk> Cc: linux...@kvack.org Cc: Andrew Morton <a...@linux-foundation.org> Signed-off-by: Dominik Brodowski <li...@dominikbrodowski.net> --- kernel/compat.c | 22 ---------------------- mm/migrate.c | 39 +++++++++++++++++++++++++++++++++++---- 2 files changed, 35 insertions(+), 26 deletions(-) diff --git a/kernel/compat.c b/kernel/compat.c index 51bdf1808943..6d21894806b4 100644 --- a/kernel/compat.c +++ b/kernel/compat.c @@ -488,28 +488,6 @@ get_compat_sigset(sigset_t *set, const compat_sigset_t __user *compat) } EXPORT_SYMBOL_GPL(get_compat_sigset); -#ifdef CONFIG_NUMA -COMPAT_SYSCALL_DEFINE6(move_pages, pid_t, pid, compat_ulong_t, nr_pages, - compat_uptr_t __user *, pages32, - const int __user *, nodes, - int __user *, status, - int, flags) -{ - const void __user * __user *pages; - int i; - - pages = compat_alloc_user_space(nr_pages * sizeof(void *)); - for (i = 0; i < nr_pages; i++) { - compat_uptr_t p; - - if (get_user(p, pages32 + i) || - put_user(compat_ptr(p), pages + i)) - return -EFAULT; - } - return sys_move_pages(pid, nr_pages, pages, nodes, status, flags); -} -#endif - /* * Allocate user-space memory for the duration of a single system call, * in order to marshall parameters inside a compat thunk. diff --git a/mm/migrate.c b/mm/migrate.c index 1e5525a25691..003886606a22 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -34,6 +34,7 @@ #include <linux/backing-dev.h> #include <linux/compaction.h> #include <linux/syscalls.h> +#include <linux/compat.h> #include <linux/hugetlb.h> #include <linux/hugetlb_cgroup.h> #include <linux/gfp.h> @@ -1745,10 +1746,10 @@ static int do_pages_stat(struct mm_struct *mm, unsigned long nr_pages, * Move a list of pages in the address space of the currently executing * process. */ -SYSCALL_DEFINE6(move_pages, pid_t, pid, unsigned long, nr_pages, - const void __user * __user *, pages, - const int __user *, nodes, - int __user *, status, int, flags) +static int kernel_move_pages(pid_t pid, unsigned long nr_pages, + const void __user * __user *pages, + const int __user *nodes, + int __user *status, int flags) { struct task_struct *task; struct mm_struct *mm; @@ -1807,6 +1808,36 @@ SYSCALL_DEFINE6(move_pages, pid_t, pid, unsigned long, nr_pages, return err; } +SYSCALL_DEFINE6(move_pages, pid_t, pid, unsigned long, nr_pages, + const void __user * __user *, pages, + const int __user *, nodes, + int __user *, status, int, flags) +{ + return kernel_move_pages(pid, nr_pages, pages, nodes, status, flags); +} + +#ifdef CONFIG_COMPAT +COMPAT_SYSCALL_DEFINE6(move_pages, pid_t, pid, compat_ulong_t, nr_pages, + compat_uptr_t __user *, pages32, + const int __user *, nodes, + int __user *, status, + int, flags) +{ + const void __user * __user *pages; + int i; + + pages = compat_alloc_user_space(nr_pages * sizeof(void *)); + for (i = 0; i < nr_pages; i++) { + compat_uptr_t p; + + if (get_user(p, pages32 + i) || + put_user(compat_ptr(p), pages + i)) + return -EFAULT; + } + return kernel_move_pages(pid, nr_pages, pages, nodes, status, flags); +} +#endif /* CONFIG_COMPAT */ + #ifdef CONFIG_NUMA_BALANCING /* * Returns true if this is a safe migration target node for misplaced NUMA -- 2.16.3
