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authorLaurent Dufour <ldufour@linux.vnet.ibm.com>2015-06-24 23:56:19 (GMT)
committerLinus Torvalds <torvalds@linux-foundation.org>2015-06-25 00:49:41 (GMT)
commit4abad2ca4a4dbdd4a218c12451231ab628f2e60c (patch)
tree4e9f1494ef5d8cffbdf379317bb144a96aaad9d8
parent2ae416b142b625c58c9ccb039aa3ef48ad0e9bae (diff)
downloadlinux-4abad2ca4a4dbdd4a218c12451231ab628f2e60c.tar.xz
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>
-rw-r--r--include/linux/mm-arch-hooks.h9
-rw-r--r--mm/mremap.c17
2 files changed, 20 insertions, 6 deletions
diff --git a/include/linux/mm-arch-hooks.h b/include/linux/mm-arch-hooks.h
index 63005e3..4efc3f5 100644
--- a/include/linux/mm-arch-hooks.h
+++ b/include/linux/mm-arch-hooks.h
@@ -13,4 +13,13 @@
#include <asm/mm-arch-hooks.h>
+#ifndef arch_remap
+static inline void arch_remap(struct mm_struct *mm,
+ unsigned long old_start, unsigned long old_end,
+ unsigned long new_start, unsigned long new_end)
+{
+}
+#define arch_remap arch_remap
+#endif
+
#endif /* _LINUX_MM_ARCH_HOOKS_H */
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 @@ static unsigned long move_vma(struct vm_area_struct *vma,
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 */