NOMMU: implement access_remote_vm
Recent vm changes brought in a new function which the core procfs code
utilizes. So implement it for nommu systems too to avoid link failures.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Simon Horman <horms@verge.net.au>
Tested-by: Ithamar Adema <ithamar.adema@team-embedded.nl>
Acked-by: Greg Ungerer <gerg@uclinux.org>
diff --git a/mm/nommu.c b/mm/nommu.c
index cb86e7d..c4c542c 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -1971,21 +1971,10 @@
}
EXPORT_SYMBOL(filemap_fault);
-/*
- * Access another process' address space.
- * - source/target buffer must be kernel space
- */
-int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, int len, int write)
+static int __access_remote_vm(struct task_struct *tsk, struct mm_struct *mm,
+ unsigned long addr, void *buf, int len, int write)
{
struct vm_area_struct *vma;
- struct mm_struct *mm;
-
- if (addr + len < addr)
- return 0;
-
- mm = get_task_mm(tsk);
- if (!mm)
- return 0;
down_read(&mm->mmap_sem);
@@ -2010,6 +1999,43 @@
}
up_read(&mm->mmap_sem);
+
+ return len;
+}
+
+/**
+ * @access_remote_vm - access another process' address space
+ * @mm: the mm_struct of the target address space
+ * @addr: start address to access
+ * @buf: source or destination buffer
+ * @len: number of bytes to transfer
+ * @write: whether the access is a write
+ *
+ * The caller must hold a reference on @mm.
+ */
+int access_remote_vm(struct mm_struct *mm, unsigned long addr,
+ void *buf, int len, int write)
+{
+ return __access_remote_vm(NULL, mm, addr, buf, len, write);
+}
+
+/*
+ * Access another process' address space.
+ * - source/target buffer must be kernel space
+ */
+int access_process_vm(struct task_struct *tsk, unsigned long addr, void *buf, int len, int write)
+{
+ struct mm_struct *mm;
+
+ if (addr + len < addr)
+ return 0;
+
+ mm = get_task_mm(tsk);
+ if (!mm)
+ return 0;
+
+ len = __access_remote_vm(tsk, mm, addr, buf, len, write);
+
mmput(mm);
return len;
}