mm: new arch_remap() hook
Some architectures would like to be triggered when a memory area is moved
through the mremap system call.
This patch introduces a new arch_remap() mm hook which is placed in the
path of mremap, and is called before the old area is unmapped (and the
arch_unmap() hook is called).
Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/mremap.c b/mm/mremap.c
index 034e2d3..a7c93ec 100644
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -22,6 +22,7 @@
#include <linux/mmu_notifier.h>
#include <linux/sched/sysctl.h>
#include <linux/uaccess.h>
+#include <linux/mm-arch-hooks.h>
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
@@ -286,13 +287,17 @@
old_len = new_len;
old_addr = new_addr;
new_addr = -ENOMEM;
- } else if (vma->vm_file && vma->vm_file->f_op->mremap) {
- err = vma->vm_file->f_op->mremap(vma->vm_file, new_vma);
- if (err < 0) {
- move_page_tables(new_vma, new_addr, vma, old_addr,
- moved_len, true);
- return err;
+ } else {
+ if (vma->vm_file && vma->vm_file->f_op->mremap) {
+ err = vma->vm_file->f_op->mremap(vma->vm_file, new_vma);
+ if (err < 0) {
+ move_page_tables(new_vma, new_addr, vma,
+ old_addr, moved_len, true);
+ return err;
+ }
}
+ arch_remap(mm, old_addr, old_addr + old_len,
+ new_addr, new_addr + new_len);
}
/* Conceal VM_ACCOUNT so old reservation is not undone */