diff options
| author | Dominik Brodowski <linux@dominikbrodowski.net> | 2018-03-17 16:08:03 +0100 |
|---|---|---|
| committer | Dominik Brodowski <linux@dominikbrodowski.net> | 2018-04-02 20:15:32 +0200 |
| commit | 7addf44388255f6fa99c83e3e2ad79cef0813698 (patch) | |
| tree | 3373275fd1a2b8455ad91b7220417ebd901baa2f /mm | |
| parent | b6e9b0babb7a02ae4f00f053974609000f00950e (diff) | |
mm: add kernel_move_pages() helper, move compat syscall to mm/migrate.c
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.GA17492@light.dominikbrodowski.net
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-mm@kvack.org
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/migrate.c | 39 |
1 files changed, 35 insertions, 4 deletions
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 @@ out: 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 |