The patch titled
Subject: mm: simplify compat_sys_move_pages
has been removed from the -mm tree. Its filename was
mm-simplify-compat_sys_move_pages.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
From: Arnd Bergmann <arnd@xxxxxxxx>
Subject: mm: simplify compat_sys_move_pages
The compat move_pages() implementation uses compat_alloc_user_space() for
converting the pointer array. Moving the compat handling into the
function itself is a bit simpler and lets us avoid the
compat_alloc_user_space() call.
Link: https://lkml.kernel.org/r/20210727144859.4150043-4-arnd@xxxxxxxxxx
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Christian Borntraeger <borntraeger@xxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxxxxxxxxx>
Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
Cc: Eric Biederman <ebiederm@xxxxxxxxxxxx>
Cc: Feng Tang <feng.tang@xxxxxxxxx>
Cc: Heiko Carstens <hca@xxxxxxxxxxxxx>
Cc: Helge Deller <deller@xxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: "James E.J. Bottomley" <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Vasily Gorbik <gor@xxxxxxxxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/migrate.c | 45 ++++++++++++++++++++++++++++++---------------
1 file changed, 30 insertions(+), 15 deletions(-)
--- a/mm/migrate.c~mm-simplify-compat_sys_move_pages
+++ a/mm/migrate.c
@@ -1900,6 +1900,23 @@ set_status:
mmap_read_unlock(mm);
}
+static int get_compat_pages_array(const void __user *chunk_pages[],
+ const void __user * __user *pages,
+ unsigned long chunk_nr)
+{
+ compat_uptr_t __user *pages32 = (compat_uptr_t __user *)pages;
+ compat_uptr_t p;
+ int i;
+
+ for (i = 0; i < chunk_nr; i++) {
+ if (get_user(p, pages32 + i))
+ return -EFAULT;
+ chunk_pages[i] = compat_ptr(p);
+ }
+
+ return 0;
+}
+
/*
* Determine the nodes of a user array of pages and store it in
* a user array of status.
@@ -1919,8 +1936,15 @@ static int do_pages_stat(struct mm_struc
if (chunk_nr > DO_PAGES_STAT_CHUNK_NR)
chunk_nr = DO_PAGES_STAT_CHUNK_NR;
- if (copy_from_user(chunk_pages, pages, chunk_nr * sizeof(*chunk_pages)))
- break;
+ if (in_compat_syscall()) {
+ if (get_compat_pages_array(chunk_pages, pages,
+ chunk_nr))
+ break;
+ } else {
+ if (copy_from_user(chunk_pages, pages,
+ chunk_nr * sizeof(*chunk_pages)))
+ break;
+ }
do_pages_stat_array(mm, chunk_nr, chunk_pages, chunk_status);
@@ -2025,23 +2049,14 @@ SYSCALL_DEFINE6(move_pages, pid_t, pid,
#ifdef CONFIG_COMPAT
COMPAT_SYSCALL_DEFINE6(move_pages, pid_t, pid, compat_ulong_t, nr_pages,
- compat_uptr_t __user *, pages32,
+ compat_uptr_t __user *, pages,
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);
+ return kernel_move_pages(pid, nr_pages,
+ (const void __user *__user *)pages,
+ nodes, status, flags);
}
#endif /* CONFIG_COMPAT */
_
Patches currently in -mm which might be from arnd@xxxxxxxx are
