untangling process_vm_..., part 2

move iov to caller's stack frame; the value we assign to it on the
next call of process_vm_rw_pages() is equal to the value it had
when the last time we were leaving process_vm_rw_pages().

drop lvec argument of process_vm_rw_pages() - it's not used anymore.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 5 insertions, 3 deletions

diff --git a/mm/process_vm_access.c b/mm/process_vm_access.c
index 7b8d63e6c30b..186ec5db6090 100644
--- a/mm/process_vm_access.c
+++ b/mm/process_vm_access.c
@@ -45,7 +45,7 @@ static int process_vm_rw_pages(struct task_struct *task,
                                unsigned long pa,
                                unsigned long start_offset,
                                unsigned long len,
-                               const struct iovec *lvec,
+                               const struct iovec **iovp,
                                unsigned long lvec_cnt,
                                unsigned long *lvec_current,
                                size_t *lvec_offset,
@@ -60,7 +60,7 @@ static int process_vm_rw_pages(struct task_struct *task,
         int ret;
         ssize_t bytes_to_copy;
         ssize_t rc = 0;
-        const struct iovec *iov = lvec + *lvec_current;
+        const struct iovec *iov = *iovp;
 
         *bytes_copied = 0;
 
@@ -149,6 +149,7 @@ end:
                         put_page(process_pages[j]);
         }
 
+        *iovp = iov;
         return rc;
 }
 
@@ -192,6 +193,7 @@ static int process_vm_rw_single_vec(unsigned long addr,
         unsigned long nr_pages_to_copy;
         unsigned long max_pages_per_loop = PVM_MAX_KMALLOC_PAGES
                 / sizeof(struct pages *);
+        const struct iovec *iov = lvec + *lvec_current;
 
         *bytes_copied = 0;
 
@@ -206,7 +208,7 @@ static int process_vm_rw_single_vec(unsigned long addr,
 
                 rc = process_vm_rw_pages(task, mm, process_pages, pa,
                                          start_offset, len,
-                                         lvec, lvec_cnt,
+                                         &iov, lvec_cnt,
                                          lvec_current, lvec_offset,
                                          vm_write, nr_pages_to_copy,
                                          &bytes_copied_loop);