[PATCH v2 0/4] syscalls: remove compat_alloc_user_space callers

[PATCH v2 0/4] syscalls: remove compat_alloc_user_space callers

[Arnd Bergmann]

From: Arnd Bergmann <arnd@arndb.de>

Going through compat_alloc_user_space() to convert indirect system call
arguments tends to add complexity compared to handling the native and
compat logic in the same code.

I have patches for all other uses of compat_alloc_user_space() as well,
and would expect that we can subsequently remove the interface itself.

Changes in v2:

- address review comments from Christoph Hellwig
- split syscall removal into a separate patch
- replace __X32_COND_SYSCALL() with individual macros for x32

Arnd Bergmann (4):
  kexec: simplify compat_sys_kexec_load
  mm: simplify compat_sys_move_pages
  mm: simplify compat numa syscalls
  compat: remove some compat entry points

 arch/arm64/include/asm/unistd32.h         |  12 +-
 arch/mips/kernel/syscalls/syscall_n32.tbl |  12 +-
 arch/mips/kernel/syscalls/syscall_o32.tbl |  12 +-
 arch/parisc/kernel/syscalls/syscall.tbl   |  10 +-
 arch/powerpc/kernel/syscalls/syscall.tbl  |  12 +-
 arch/s390/kernel/syscalls/syscall.tbl     |  12 +-
 arch/sparc/kernel/syscalls/syscall.tbl    |  12 +-
 arch/x86/entry/syscall_x32.c              |   2 +
 arch/x86/entry/syscalls/syscall_32.tbl    |   6 +-
 arch/x86/entry/syscalls/syscall_64.tbl    |   4 +-
 include/linux/compat.h                    |  26 ---
 include/linux/kexec.h                     |   2 -
 include/uapi/asm-generic/unistd.h         |  12 +-
 kernel/kexec.c                            |  90 ++++------
 kernel/sys_ni.c                           |   5 -
 mm/mempolicy.c                            | 195 +++++-----------------
 mm/migrate.c                              |  50 +++---
 17 files changed, 155 insertions(+), 319 deletions(-)

Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arch@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-mm@kvack.org
Cc: kexec@lists.infradead.org
-- 
2.27.0

[PATCH v2 1/4] kexec: simplify compat_sys_kexec_load

[Arnd Bergmann]

From: Arnd Bergmann <arnd@arndb.de>

The compat version of sys_kexec_load() uses compat_alloc_user_space to
convert the user-provided arguments into the native format.

Move the conversion into the regular implementation with
an in_compat_syscall() check to simplify it and avoid the
compat_alloc_user_space() call.

compat_sys_kexec_load() now behaves the same as sys_kexec_load().

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 include/linux/kexec.h |  2 -
 kernel/kexec.c        | 95 +++++++++++++++++++------------------------
 2 files changed, 42 insertions(+), 55 deletions(-)

diff --git a/include/linux/kexec.h b/include/linux/kexec.h
index 9e93bef52968..7b6717cd5c4a 100644
--- a/include/linux/kexec.h
+++ b/include/linux/kexec.h
@@ -88,14 +88,12 @@ struct kexec_segment {
 	size_t memsz;
 };
 
-#ifdef CONFIG_COMPAT
 struct compat_kexec_segment {
 	compat_uptr_t buf;
 	compat_size_t bufsz;
 	compat_ulong_t mem;	/* User space sees this as a (void *) ... */
 	compat_size_t memsz;
 };
-#endif
 
 #ifdef CONFIG_KEXEC_FILE
 struct purgatory_info {
diff --git a/kernel/kexec.c b/kernel/kexec.c
index c82c6c06f051..ec04791eea3e 100644
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -19,21 +19,46 @@
 
 #include "kexec_internal.h"
 
+static int copy_user_compat_segment_list(struct kimage *image,
+					 unsigned long nr_segments,
+					 void __user *segments)
+{
+	struct compat_kexec_segment __user *cs = segments;
+	struct compat_kexec_segment segment;
+	int i;
+
+	for (i=0; i < nr_segments; i++) {
+		if (copy_from_user(&segment, &cs[i], sizeof(segment)))
+			return -EFAULT;
+
+		image->segment[i] = (struct kexec_segment) {
+			.buf   = compat_ptr(segment.buf),
+			.bufsz = segment.bufsz,
+			.mem   = segment.mem,
+			.memsz = segment.memsz,
+		};
+	}
+
+	return 0;
+}
+
+
 static int copy_user_segment_list(struct kimage *image,
 				  unsigned long nr_segments,
 				  struct kexec_segment __user *segments)
 {
-	int ret;
 	size_t segment_bytes;
 
 	/* Read in the segments */
 	image->nr_segments = nr_segments;
 	segment_bytes = nr_segments * sizeof(*segments);
-	ret = copy_from_user(image->segment, segments, segment_bytes);
-	if (ret)
-		ret = -EFAULT;
+	if (in_compat_syscall())
+		return copy_user_compat_segment_list(image, nr_segments, segments);
 
-	return ret;
+	if (copy_from_user(image->segment, segments, segment_bytes))
+		return -EFAULT;
+
+	return 0;
 }
 
 static int kimage_alloc_init(struct kimage **rimage, unsigned long entry,
@@ -233,8 +258,9 @@ static inline int kexec_load_check(unsigned long nr_segments,
 	return 0;
 }
 
-SYSCALL_DEFINE4(kexec_load, unsigned long, entry, unsigned long, nr_segments,
-		struct kexec_segment __user *, segments, unsigned long, flags)
+static int kernel_kexec_load(unsigned long entry, unsigned long nr_segments,
+			     struct kexec_segment __user * segments,
+			     unsigned long flags)
 {
 	int result;
 
@@ -265,57 +291,20 @@ SYSCALL_DEFINE4(kexec_load, unsigned long, entry, unsigned long, nr_segments,
 	return result;
 }
 
+SYSCALL_DEFINE4(kexec_load, unsigned long, entry, unsigned long, nr_segments,
+		struct kexec_segment __user *, segments, unsigned long, flags)
+{
+	return kernel_kexec_load(entry, nr_segments, segments, flags);
+}
+
 #ifdef CONFIG_COMPAT
 COMPAT_SYSCALL_DEFINE4(kexec_load, compat_ulong_t, entry,
 		       compat_ulong_t, nr_segments,
 		       struct compat_kexec_segment __user *, segments,
 		       compat_ulong_t, flags)
 {
-	struct compat_kexec_segment in;
-	struct kexec_segment out, __user *ksegments;
-	unsigned long i, result;
-
-	result = kexec_load_check(nr_segments, flags);
-	if (result)
-		return result;
-
-	/* Don't allow clients that don't understand the native
-	 * architecture to do anything.
-	 */
-	if ((flags & KEXEC_ARCH_MASK) == KEXEC_ARCH_DEFAULT)
-		return -EINVAL;
-
-	ksegments = compat_alloc_user_space(nr_segments * sizeof(out));
-	for (i = 0; i < nr_segments; i++) {
-		result = copy_from_user(&in, &segments[i], sizeof(in));
-		if (result)
-			return -EFAULT;
-
-		out.buf   = compat_ptr(in.buf);
-		out.bufsz = in.bufsz;
-		out.mem   = in.mem;
-		out.memsz = in.memsz;
-
-		result = copy_to_user(&ksegments[i], &out, sizeof(out));
-		if (result)
-			return -EFAULT;
-	}
-
-	/* Because we write directly to the reserved memory
-	 * region when loading crash kernels we need a mutex here to
-	 * prevent multiple crash  kernels from attempting to load
-	 * simultaneously, and to prevent a crash kernel from loading
-	 * over the top of a in use crash kernel.
-	 *
-	 * KISS: always take the mutex.
-	 */
-	if (!mutex_trylock(&kexec_mutex))
-		return -EBUSY;
-
-	result = do_kexec_load(entry, nr_segments, ksegments, flags);
-
-	mutex_unlock(&kexec_mutex);
-
-	return result;
+	return kernel_kexec_load(entry, nr_segments,
+				 (struct kexec_segment __user *)segments,
+				 flags);
 }
 #endif
-- 
2.27.0

[PATCH v2 2/4] mm: simplify compat_sys_move_pages

[Arnd Bergmann]

From: Arnd Bergmann <arnd@arndb.de>

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.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 mm/migrate.c | 45 ++++++++++++++++++++++++++++++---------------
 1 file changed, 30 insertions(+), 15 deletions(-)

diff --git a/mm/migrate.c b/mm/migrate.c
index 5ca5842df5db..016e39809ca5 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1830,6 +1830,23 @@ static void do_pages_stat_array(struct mm_struct *mm, unsigned long nr_pages,
 	mmap_read_unlock(mm);
 }
 
+static int put_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.
@@ -1849,8 +1866,15 @@ static int do_pages_stat(struct mm_struct *mm, unsigned long nr_pages,
 		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 (put_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);
 
@@ -1955,23 +1979,14 @@ SYSCALL_DEFINE6(move_pages, pid_t, pid, unsigned long, nr_pages,
 
 #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 */
 
-- 
2.27.0

[PATCH v2 3/4] mm: simplify compat numa syscalls

[Arnd Bergmann]

From: Arnd Bergmann <arnd@arndb.de>

The compat implementations for mbind, get_mempolicy, set_mempolicy
and migrate_pages are just there to handle the subtly different
layout of bitmaps on 32-bit hosts.

The compat implementation however lacks some of the checks that
are present in the native one, in particular for checking that
the extra bits are all zero when user space has a larger mask
size than the kernel. Worse, those extra bits do not get cleared
when copying in or out of the kernel, which can lead to incorrect
data as well.

Unify the implementation to handle the compat bitmap layout directly
in the get_nodes() and copy_nodes_to_user() helpers.  Splitting out
the get_bitmap() helper from get_nodes() also helps readability of the
native case.

On x86, two additional problems are addressed by this: compat tasks can
pass a bitmap at the end of a mapping, causing a fault when reading
across the page boundary for a 64-bit word. x32 tasks might also run
into problems with get_mempolicy corrupting data when an odd number of
32-bit words gets passed.

On parisc the migrate_pages() system call apparently had the wrong
calling convention, as big-endian architectures expect the words
inside of a bitmap to be swapped. This is not a problem though
since parisc has no NUMA support.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 mm/mempolicy.c | 174 +++++++++++++++----------------------------------
 1 file changed, 53 insertions(+), 121 deletions(-)

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 3fde772ef5ef..fb5e533667f6 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -1371,16 +1371,32 @@ static long do_mbind(unsigned long start, unsigned long len,
 /*
  * User space interface with variable sized bitmaps for nodelists.
  */
+static int get_bitmap(unsigned long *mask, const unsigned long __user *nmask,
+		      unsigned long maxnode)
+{
+	unsigned long nlongs = BITS_TO_LONGS(maxnode);
+	int ret;
+
+	if (in_compat_syscall())
+		ret = compat_get_bitmap(mask,
+				(const compat_ulong_t __user *)nmask,
+				maxnode);
+	else
+		ret = copy_from_user(mask, nmask, nlongs*sizeof(unsigned long));
+
+	if (ret)
+		return -EFAULT;
+
+	if (maxnode % BITS_PER_LONG)
+		mask[nlongs-1] &= (1UL << (maxnode % BITS_PER_LONG)) - 1;
+
+	return 0;
+}
 
 /* Copy a node mask from user space. */
 static int get_nodes(nodemask_t *nodes, const unsigned long __user *nmask,
 		     unsigned long maxnode)
 {
-	unsigned long k;
-	unsigned long t;
-	unsigned long nlongs;
-	unsigned long endmask;
-
 	--maxnode;
 	nodes_clear(*nodes);
 	if (maxnode == 0 || !nmask)
@@ -1388,49 +1404,29 @@ static int get_nodes(nodemask_t *nodes, const unsigned long __user *nmask,
 	if (maxnode > PAGE_SIZE*BITS_PER_BYTE)
 		return -EINVAL;
 
-	nlongs = BITS_TO_LONGS(maxnode);
-	if ((maxnode % BITS_PER_LONG) == 0)
-		endmask = ~0UL;
-	else
-		endmask = (1UL << (maxnode % BITS_PER_LONG)) - 1;
-
 	/*
 	 * When the user specified more nodes than supported just check
-	 * if the non supported part is all zero.
-	 *
-	 * If maxnode have more longs than MAX_NUMNODES, check
-	 * the bits in that area first. And then go through to
-	 * check the rest bits which equal or bigger than MAX_NUMNODES.
-	 * Otherwise, just check bits [MAX_NUMNODES, maxnode).
+	 * if the non supported part is all zero, one word at a time,
+	 * starting at the end.
 	 */
-	if (nlongs > BITS_TO_LONGS(MAX_NUMNODES)) {
-		for (k = BITS_TO_LONGS(MAX_NUMNODES); k < nlongs; k++) {
-			if (get_user(t, nmask + k))
-				return -EFAULT;
-			if (k == nlongs - 1) {
-				if (t & endmask)
-					return -EINVAL;
-			} else if (t)
-				return -EINVAL;
-		}
-		nlongs = BITS_TO_LONGS(MAX_NUMNODES);
-		endmask = ~0UL;
-	}
+	while (maxnode > MAX_NUMNODES) {
+		unsigned long bits = min_t(unsigned long, maxnode, BITS_PER_LONG);
+		unsigned long t;
 
-	if (maxnode > MAX_NUMNODES && MAX_NUMNODES % BITS_PER_LONG != 0) {
-		unsigned long valid_mask = endmask;
-
-		valid_mask &= ~((1UL << (MAX_NUMNODES % BITS_PER_LONG)) - 1);
-		if (get_user(t, nmask + nlongs - 1))
+		if (get_bitmap(&t, &nmask[maxnode / BITS_PER_LONG], bits))
 			return -EFAULT;
-		if (t & valid_mask)
+
+		if (maxnode - bits >= MAX_NUMNODES) {
+			maxnode -= bits;
+		} else {
+			maxnode = MAX_NUMNODES;
+			t &= ~((1UL << (MAX_NUMNODES % BITS_PER_LONG)) - 1);
+		}
+		if (t)
 			return -EINVAL;
 	}
 
-	if (copy_from_user(nodes_addr(*nodes), nmask, nlongs*sizeof(unsigned long)))
-		return -EFAULT;
-	nodes_addr(*nodes)[nlongs-1] &= endmask;
-	return 0;
+	return get_bitmap(nodes_addr(*nodes), nmask, maxnode);
 }
 
 /* Copy a kernel node mask to user space */
@@ -1439,6 +1435,10 @@ static int copy_nodes_to_user(unsigned long __user *mask, unsigned long maxnode,
 {
 	unsigned long copy = ALIGN(maxnode-1, 64) / 8;
 	unsigned int nbytes = BITS_TO_LONGS(nr_node_ids) * sizeof(long);
+	bool compat = in_compat_syscall();
+
+	if (compat)
+		nbytes = BITS_TO_COMPAT_LONGS(nr_node_ids) * sizeof(compat_long_t);
 
 	if (copy > nbytes) {
 		if (copy > PAGE_SIZE)
@@ -1447,6 +1447,11 @@ static int copy_nodes_to_user(unsigned long __user *mask, unsigned long maxnode,
 			return -EFAULT;
 		copy = nbytes;
 	}
+
+	if (compat)
+		return compat_put_bitmap((compat_ulong_t __user *)mask,
+					 nodes_addr(*nodes), maxnode);
+
 	return copy_to_user(mask, nodes_addr(*nodes), copy) ? -EFAULT : 0;
 }
 
@@ -1645,72 +1650,22 @@ COMPAT_SYSCALL_DEFINE5(get_mempolicy, int __user *, policy,
 		       compat_ulong_t, maxnode,
 		       compat_ulong_t, addr, compat_ulong_t, flags)
 {
-	long err;
-	unsigned long __user *nm = NULL;
-	unsigned long nr_bits, alloc_size;
-	DECLARE_BITMAP(bm, MAX_NUMNODES);
-
-	nr_bits = min_t(unsigned long, maxnode-1, nr_node_ids);
-	alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8;
-
-	if (nmask)
-		nm = compat_alloc_user_space(alloc_size);
-
-	err = kernel_get_mempolicy(policy, nm, nr_bits+1, addr, flags);
-
-	if (!err && nmask) {
-		unsigned long copy_size;
-		copy_size = min_t(unsigned long, sizeof(bm), alloc_size);
-		err = copy_from_user(bm, nm, copy_size);
-		/* ensure entire bitmap is zeroed */
-		err |= clear_user(nmask, ALIGN(maxnode-1, 8) / 8);
-		err |= compat_put_bitmap(nmask, bm, nr_bits);
-	}
-
-	return err;
+	return kernel_get_mempolicy(policy, (unsigned long __user *)nmask,
+				    maxnode, addr, flags);
 }
 
 COMPAT_SYSCALL_DEFINE3(set_mempolicy, int, mode, compat_ulong_t __user *, nmask,
 		       compat_ulong_t, maxnode)
 {
-	unsigned long __user *nm = NULL;
-	unsigned long nr_bits, alloc_size;
-	DECLARE_BITMAP(bm, MAX_NUMNODES);
-
-	nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES);
-	alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8;
-
-	if (nmask) {
-		if (compat_get_bitmap(bm, nmask, nr_bits))
-			return -EFAULT;
-		nm = compat_alloc_user_space(alloc_size);
-		if (copy_to_user(nm, bm, alloc_size))
-			return -EFAULT;
-	}
-
-	return kernel_set_mempolicy(mode, nm, nr_bits+1);
+	return kernel_set_mempolicy(mode, (unsigned long __user *)nmask, maxnode);
 }
 
 COMPAT_SYSCALL_DEFINE6(mbind, compat_ulong_t, start, compat_ulong_t, len,
 		       compat_ulong_t, mode, compat_ulong_t __user *, nmask,
 		       compat_ulong_t, maxnode, compat_ulong_t, flags)
 {
-	unsigned long __user *nm = NULL;
-	unsigned long nr_bits, alloc_size;
-	nodemask_t bm;
-
-	nr_bits = min_t(unsigned long, maxnode-1, MAX_NUMNODES);
-	alloc_size = ALIGN(nr_bits, BITS_PER_LONG) / 8;
-
-	if (nmask) {
-		if (compat_get_bitmap(nodes_addr(bm), nmask, nr_bits))
-			return -EFAULT;
-		nm = compat_alloc_user_space(alloc_size);
-		if (copy_to_user(nm, nodes_addr(bm), alloc_size))
-			return -EFAULT;
-	}
-
-	return kernel_mbind(start, len, mode, nm, nr_bits+1, flags);
+	return kernel_mbind(start, len, mode, (unsigned long __user *)nmask,
+			    maxnode, flags);
 }
 
 COMPAT_SYSCALL_DEFINE4(migrate_pages, compat_pid_t, pid,
@@ -1718,32 +1673,9 @@ COMPAT_SYSCALL_DEFINE4(migrate_pages, compat_pid_t, pid,
 		       const compat_ulong_t __user *, old_nodes,
 		       const compat_ulong_t __user *, new_nodes)
 {
-	unsigned long __user *old = NULL;
-	unsigned long __user *new = NULL;
-	nodemask_t tmp_mask;
-	unsigned long nr_bits;
-	unsigned long size;
-
-	nr_bits = min_t(unsigned long, maxnode - 1, MAX_NUMNODES);
-	size = ALIGN(nr_bits, BITS_PER_LONG) / 8;
-	if (old_nodes) {
-		if (compat_get_bitmap(nodes_addr(tmp_mask), old_nodes, nr_bits))
-			return -EFAULT;
-		old = compat_alloc_user_space(new_nodes ? size * 2 : size);
-		if (new_nodes)
-			new = old + size / sizeof(unsigned long);
-		if (copy_to_user(old, nodes_addr(tmp_mask), size))
-			return -EFAULT;
-	}
-	if (new_nodes) {
-		if (compat_get_bitmap(nodes_addr(tmp_mask), new_nodes, nr_bits))
-			return -EFAULT;
-		if (new == NULL)
-			new = compat_alloc_user_space(size);
-		if (copy_to_user(new, nodes_addr(tmp_mask), size))
-			return -EFAULT;
-	}
-	return kernel_migrate_pages(pid, nr_bits + 1, old, new);
+	return kernel_migrate_pages(pid, maxnode,
+				    (const unsigned long __user *)old_nodes,
+				    (const unsigned long __user *)new_nodes);
 }
 
 #endif /* CONFIG_COMPAT */
-- 
2.27.0

[PATCH v2 4/4] compat: remove some compat entry points

[Arnd Bergmann]

From: Arnd Bergmann <arnd@arndb.de>

These are all handled correctly when calling the native
system call entry point, so remove the special cases.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 arch/arm64/include/asm/unistd32.h         | 12 ++++----
 arch/mips/kernel/syscalls/syscall_n32.tbl | 12 ++++----
 arch/mips/kernel/syscalls/syscall_o32.tbl | 12 ++++----
 arch/parisc/kernel/syscalls/syscall.tbl   | 10 +++---
 arch/powerpc/kernel/syscalls/syscall.tbl  | 12 ++++----
 arch/s390/kernel/syscalls/syscall.tbl     | 12 ++++----
 arch/sparc/kernel/syscalls/syscall.tbl    | 12 ++++----
 arch/x86/entry/syscall_x32.c              |  2 ++
 arch/x86/entry/syscalls/syscall_32.tbl    |  6 ++--
 arch/x86/entry/syscalls/syscall_64.tbl    |  4 +--
 include/linux/compat.h                    | 26 ----------------
 include/uapi/asm-generic/unistd.h         | 12 ++++----
 kernel/kexec.c                            | 23 ++------------
 kernel/sys_ni.c                           |  5 ---
 mm/mempolicy.c                            | 37 -----------------------
 mm/migrate.c                              | 13 --------
 16 files changed, 56 insertions(+), 154 deletions(-)

diff --git a/arch/arm64/include/asm/unistd32.h b/arch/arm64/include/asm/unistd32.h
index 107f08e03b9f..25ae90737207 100644
--- a/arch/arm64/include/asm/unistd32.h
+++ b/arch/arm64/include/asm/unistd32.h
@@ -649,11 +649,11 @@ __SYSCALL(__NR_inotify_add_watch, sys_inotify_add_watch)
 #define __NR_inotify_rm_watch 318
 __SYSCALL(__NR_inotify_rm_watch, sys_inotify_rm_watch)
 #define __NR_mbind 319
-__SYSCALL(__NR_mbind, compat_sys_mbind)
+__SYSCALL(__NR_mbind, sys_mbind)
 #define __NR_get_mempolicy 320
-__SYSCALL(__NR_get_mempolicy, compat_sys_get_mempolicy)
+__SYSCALL(__NR_get_mempolicy, sys_get_mempolicy)
 #define __NR_set_mempolicy 321
-__SYSCALL(__NR_set_mempolicy, compat_sys_set_mempolicy)
+__SYSCALL(__NR_set_mempolicy, sys_set_mempolicy)
 #define __NR_openat 322
 __SYSCALL(__NR_openat, compat_sys_openat)
 #define __NR_mkdirat 323
@@ -699,13 +699,13 @@ __SYSCALL(__NR_tee, sys_tee)
 #define __NR_vmsplice 343
 __SYSCALL(__NR_vmsplice, sys_vmsplice)
 #define __NR_move_pages 344
-__SYSCALL(__NR_move_pages, compat_sys_move_pages)
+__SYSCALL(__NR_move_pages, sys_move_pages)
 #define __NR_getcpu 345
 __SYSCALL(__NR_getcpu, sys_getcpu)
 #define __NR_epoll_pwait 346
 __SYSCALL(__NR_epoll_pwait, compat_sys_epoll_pwait)
 #define __NR_kexec_load 347
-__SYSCALL(__NR_kexec_load, compat_sys_kexec_load)
+__SYSCALL(__NR_kexec_load, sys_kexec_load)
 #define __NR_utimensat 348
 __SYSCALL(__NR_utimensat, sys_utimensat_time32)
 #define __NR_signalfd 349
@@ -811,7 +811,7 @@ __SYSCALL(__NR_rseq, sys_rseq)
 #define __NR_io_pgetevents 399
 __SYSCALL(__NR_io_pgetevents, compat_sys_io_pgetevents)
 #define __NR_migrate_pages 400
-__SYSCALL(__NR_migrate_pages, compat_sys_migrate_pages)
+__SYSCALL(__NR_migrate_pages, sys_migrate_pages)
 #define __NR_kexec_file_load 401
 __SYSCALL(__NR_kexec_file_load, sys_kexec_file_load)
 /* 402 is unused */
diff --git a/arch/mips/kernel/syscalls/syscall_n32.tbl b/arch/mips/kernel/syscalls/syscall_n32.tbl
index 32817c954435..fe1ce23b8e57 100644
--- a/arch/mips/kernel/syscalls/syscall_n32.tbl
+++ b/arch/mips/kernel/syscalls/syscall_n32.tbl
@@ -239,9 +239,9 @@
 228	n32	clock_nanosleep			sys_clock_nanosleep_time32
 229	n32	tgkill				sys_tgkill
 230	n32	utimes				sys_utimes_time32
-231	n32	mbind				compat_sys_mbind
-232	n32	get_mempolicy			compat_sys_get_mempolicy
-233	n32	set_mempolicy			compat_sys_set_mempolicy
+231	n32	mbind				sys_mbind
+232	n32	get_mempolicy			sys_get_mempolicy
+233	n32	set_mempolicy			sys_set_mempolicy
 234	n32	mq_open				compat_sys_mq_open
 235	n32	mq_unlink			sys_mq_unlink
 236	n32	mq_timedsend			sys_mq_timedsend_time32
@@ -258,7 +258,7 @@
 247	n32	inotify_init			sys_inotify_init
 248	n32	inotify_add_watch		sys_inotify_add_watch
 249	n32	inotify_rm_watch		sys_inotify_rm_watch
-250	n32	migrate_pages			compat_sys_migrate_pages
+250	n32	migrate_pages			sys_migrate_pages
 251	n32	openat				sys_openat
 252	n32	mkdirat				sys_mkdirat
 253	n32	mknodat				sys_mknodat
@@ -279,10 +279,10 @@
 268	n32	sync_file_range			sys_sync_file_range
 269	n32	tee				sys_tee
 270	n32	vmsplice			sys_vmsplice
-271	n32	move_pages			compat_sys_move_pages
+271	n32	move_pages			sys_move_pages
 272	n32	set_robust_list			compat_sys_set_robust_list
 273	n32	get_robust_list			compat_sys_get_robust_list
-274	n32	kexec_load			compat_sys_kexec_load
+274	n32	kexec_load			sys_kexec_load
 275	n32	getcpu				sys_getcpu
 276	n32	epoll_pwait			compat_sys_epoll_pwait
 277	n32	ioprio_set			sys_ioprio_set
diff --git a/arch/mips/kernel/syscalls/syscall_o32.tbl b/arch/mips/kernel/syscalls/syscall_o32.tbl
index 29f5f28cf5ce..96982414890f 100644
--- a/arch/mips/kernel/syscalls/syscall_o32.tbl
+++ b/arch/mips/kernel/syscalls/syscall_o32.tbl
@@ -279,9 +279,9 @@
 265	o32	clock_nanosleep			sys_clock_nanosleep_time32
 266	o32	tgkill				sys_tgkill
 267	o32	utimes				sys_utimes_time32
-268	o32	mbind				sys_mbind			compat_sys_mbind
-269	o32	get_mempolicy			sys_get_mempolicy		compat_sys_get_mempolicy
-270	o32	set_mempolicy			sys_set_mempolicy		compat_sys_set_mempolicy
+268	o32	mbind				sys_mbind
+269	o32	get_mempolicy			sys_get_mempolicy
+270	o32	set_mempolicy			sys_set_mempolicy
 271	o32	mq_open				sys_mq_open			compat_sys_mq_open
 272	o32	mq_unlink			sys_mq_unlink
 273	o32	mq_timedsend			sys_mq_timedsend_time32
@@ -298,7 +298,7 @@
 284	o32	inotify_init			sys_inotify_init
 285	o32	inotify_add_watch		sys_inotify_add_watch
 286	o32	inotify_rm_watch		sys_inotify_rm_watch
-287	o32	migrate_pages			sys_migrate_pages		compat_sys_migrate_pages
+287	o32	migrate_pages			sys_migrate_pages
 288	o32	openat				sys_openat			compat_sys_openat
 289	o32	mkdirat				sys_mkdirat
 290	o32	mknodat				sys_mknodat
@@ -319,10 +319,10 @@
 305	o32	sync_file_range			sys_sync_file_range		sys32_sync_file_range
 306	o32	tee				sys_tee
 307	o32	vmsplice			sys_vmsplice
-308	o32	move_pages			sys_move_pages			compat_sys_move_pages
+308	o32	move_pages			sys_move_pages
 309	o32	set_robust_list			sys_set_robust_list		compat_sys_set_robust_list
 310	o32	get_robust_list			sys_get_robust_list		compat_sys_get_robust_list
-311	o32	kexec_load			sys_kexec_load			compat_sys_kexec_load
+311	o32	kexec_load			sys_kexec_load
 312	o32	getcpu				sys_getcpu
 313	o32	epoll_pwait			sys_epoll_pwait			compat_sys_epoll_pwait
 314	o32	ioprio_set			sys_ioprio_set
diff --git a/arch/parisc/kernel/syscalls/syscall.tbl b/arch/parisc/kernel/syscalls/syscall.tbl
index f375ea528e59..fe5ca85a0598 100644
--- a/arch/parisc/kernel/syscalls/syscall.tbl
+++ b/arch/parisc/kernel/syscalls/syscall.tbl
@@ -292,9 +292,9 @@
 258	32	clock_nanosleep		sys_clock_nanosleep_time32
 258	64	clock_nanosleep		sys_clock_nanosleep
 259	common	tgkill			sys_tgkill
-260	common	mbind			sys_mbind			compat_sys_mbind
-261	common	get_mempolicy		sys_get_mempolicy		compat_sys_get_mempolicy
-262	common	set_mempolicy		sys_set_mempolicy		compat_sys_set_mempolicy
+260	common	mbind			sys_mbind
+261	common	get_mempolicy		sys_get_mempolicy
+262	common	set_mempolicy		sys_set_mempolicy
 # 263 was vserver
 264	common	add_key			sys_add_key
 265	common	request_key		sys_request_key
@@ -331,12 +331,12 @@
 292	64	sync_file_range		sys_sync_file_range
 293	common	tee			sys_tee
 294	common	vmsplice		sys_vmsplice
-295	common	move_pages		sys_move_pages			compat_sys_move_pages
+295	common	move_pages		sys_move_pages
 296	common	getcpu			sys_getcpu
 297	common	epoll_pwait		sys_epoll_pwait			compat_sys_epoll_pwait
 298	common	statfs64		sys_statfs64			compat_sys_statfs64
 299	common	fstatfs64		sys_fstatfs64			compat_sys_fstatfs64
-300	common	kexec_load		sys_kexec_load			compat_sys_kexec_load
+300	common	kexec_load		sys_kexec_load
 301	32	utimensat		sys_utimensat_time32
 301	64	utimensat		sys_utimensat
 302	common	signalfd		sys_signalfd			compat_sys_signalfd
diff --git a/arch/powerpc/kernel/syscalls/syscall.tbl b/arch/powerpc/kernel/syscalls/syscall.tbl
index 1275daec7fec..8e2cce038adc 100644
--- a/arch/powerpc/kernel/syscalls/syscall.tbl
+++ b/arch/powerpc/kernel/syscalls/syscall.tbl
@@ -338,10 +338,10 @@
 256	64	sys_debug_setcontext		sys_ni_syscall
 256	spu	sys_debug_setcontext		sys_ni_syscall
 # 257 reserved for vserver
-258	nospu	migrate_pages			sys_migrate_pages		compat_sys_migrate_pages
-259	nospu	mbind				sys_mbind			compat_sys_mbind
-260	nospu	get_mempolicy			sys_get_mempolicy		compat_sys_get_mempolicy
-261	nospu	set_mempolicy			sys_set_mempolicy		compat_sys_set_mempolicy
+258	nospu	migrate_pages			sys_migrate_pages
+259	nospu	mbind				sys_mbind
+260	nospu	get_mempolicy			sys_get_mempolicy
+261	nospu	set_mempolicy			sys_set_mempolicy
 262	nospu	mq_open				sys_mq_open			compat_sys_mq_open
 263	nospu	mq_unlink			sys_mq_unlink
 264	32	mq_timedsend			sys_mq_timedsend_time32
@@ -350,7 +350,7 @@
 265	64	mq_timedreceive			sys_mq_timedreceive
 266	nospu	mq_notify			sys_mq_notify			compat_sys_mq_notify
 267	nospu	mq_getsetattr			sys_mq_getsetattr		compat_sys_mq_getsetattr
-268	nospu	kexec_load			sys_kexec_load			compat_sys_kexec_load
+268	nospu	kexec_load			sys_kexec_load
 269	nospu	add_key				sys_add_key
 270	nospu	request_key			sys_request_key
 271	nospu	keyctl				sys_keyctl			compat_sys_keyctl
@@ -389,7 +389,7 @@
 298	common	faccessat			sys_faccessat
 299	common	get_robust_list			sys_get_robust_list		compat_sys_get_robust_list
 300	common	set_robust_list			sys_set_robust_list		compat_sys_set_robust_list
-301	common	move_pages			sys_move_pages			compat_sys_move_pages
+301	common	move_pages			sys_move_pages
 302	common	getcpu				sys_getcpu
 303	nospu	epoll_pwait			sys_epoll_pwait			compat_sys_epoll_pwait
 304	32	utimensat			sys_utimensat_time32
diff --git a/arch/s390/kernel/syscalls/syscall.tbl b/arch/s390/kernel/syscalls/syscall.tbl
index 28c168000483..2147a1e59165 100644
--- a/arch/s390/kernel/syscalls/syscall.tbl
+++ b/arch/s390/kernel/syscalls/syscall.tbl
@@ -274,16 +274,16 @@
 265  common	statfs64		sys_statfs64			compat_sys_statfs64
 266  common	fstatfs64		sys_fstatfs64			compat_sys_fstatfs64
 267  common	remap_file_pages	sys_remap_file_pages		sys_remap_file_pages
-268  common	mbind			sys_mbind			compat_sys_mbind
-269  common	get_mempolicy		sys_get_mempolicy		compat_sys_get_mempolicy
-270  common	set_mempolicy		sys_set_mempolicy		compat_sys_set_mempolicy
+268  common	mbind			sys_mbind			sys_mbind
+269  common	get_mempolicy		sys_get_mempolicy		sys_get_mempolicy
+270  common	set_mempolicy		sys_set_mempolicy		sys_set_mempolicy
 271  common	mq_open			sys_mq_open			compat_sys_mq_open
 272  common	mq_unlink		sys_mq_unlink			sys_mq_unlink
 273  common	mq_timedsend		sys_mq_timedsend		sys_mq_timedsend_time32
 274  common	mq_timedreceive		sys_mq_timedreceive		sys_mq_timedreceive_time32
 275  common	mq_notify		sys_mq_notify			compat_sys_mq_notify
 276  common	mq_getsetattr		sys_mq_getsetattr		compat_sys_mq_getsetattr
-277  common	kexec_load		sys_kexec_load			compat_sys_kexec_load
+277  common	kexec_load		sys_kexec_load			sys_kexec_load
 278  common	add_key			sys_add_key			sys_add_key
 279  common	request_key		sys_request_key			sys_request_key
 280  common	keyctl			sys_keyctl			compat_sys_keyctl
@@ -293,7 +293,7 @@
 284  common	inotify_init		sys_inotify_init		sys_inotify_init
 285  common	inotify_add_watch	sys_inotify_add_watch		sys_inotify_add_watch
 286  common	inotify_rm_watch	sys_inotify_rm_watch		sys_inotify_rm_watch
-287  common	migrate_pages		sys_migrate_pages		compat_sys_migrate_pages
+287  common	migrate_pages		sys_migrate_pages		sys_migrate_pages
 288  common	openat			sys_openat			compat_sys_openat
 289  common	mkdirat			sys_mkdirat			sys_mkdirat
 290  common	mknodat			sys_mknodat			sys_mknodat
@@ -317,7 +317,7 @@
 307  common	sync_file_range		sys_sync_file_range		compat_sys_s390_sync_file_range
 308  common	tee			sys_tee				sys_tee
 309  common	vmsplice		sys_vmsplice			sys_vmsplice
-310  common	move_pages		sys_move_pages			compat_sys_move_pages
+310  common	move_pages		sys_move_pages			sys_move_pages
 311  common	getcpu			sys_getcpu			sys_getcpu
 312  common	epoll_pwait		sys_epoll_pwait			compat_sys_epoll_pwait
 313  common	utimes			sys_utimes			sys_utimes_time32
diff --git a/arch/sparc/kernel/syscalls/syscall.tbl b/arch/sparc/kernel/syscalls/syscall.tbl
index 78160260991b..522555e5f4a3 100644
--- a/arch/sparc/kernel/syscalls/syscall.tbl
+++ b/arch/sparc/kernel/syscalls/syscall.tbl
@@ -365,12 +365,12 @@
 299	common	unshare			sys_unshare
 300	common	set_robust_list		sys_set_robust_list		compat_sys_set_robust_list
 301	common	get_robust_list		sys_get_robust_list		compat_sys_get_robust_list
-302	common	migrate_pages		sys_migrate_pages		compat_sys_migrate_pages
-303	common	mbind			sys_mbind			compat_sys_mbind
-304	common	get_mempolicy		sys_get_mempolicy		compat_sys_get_mempolicy
-305	common	set_mempolicy		sys_set_mempolicy		compat_sys_set_mempolicy
-306	common	kexec_load		sys_kexec_load			compat_sys_kexec_load
-307	common	move_pages		sys_move_pages			compat_sys_move_pages
+302	common	migrate_pages		sys_migrate_pages
+303	common	mbind			sys_mbind
+304	common	get_mempolicy		sys_get_mempolicy
+305	common	set_mempolicy		sys_set_mempolicy
+306	common	kexec_load		sys_kexec_load
+307	common	move_pages		sys_move_pages
 308	common	getcpu			sys_getcpu
 309	common	epoll_pwait		sys_epoll_pwait			compat_sys_epoll_pwait
 310	32	utimensat		sys_utimensat_time32
diff --git a/arch/x86/entry/syscall_x32.c b/arch/x86/entry/syscall_x32.c
index f2fe0a33bcfd..921473281497 100644
--- a/arch/x86/entry/syscall_x32.c
+++ b/arch/x86/entry/syscall_x32.c
@@ -19,6 +19,8 @@
 #define __x32_sys_vmsplice	__x64_sys_vmsplice
 #define __x32_sys_process_vm_readv	__x64_sys_process_vm_readv
 #define __x32_sys_process_vm_writev	__x64_sys_process_vm_writev
+#define __x32_sys_kexec_load	__x64_sys_kexec_load
+#define __x32_sys_move_pages	__x64_sys_move_pages
 
 #define __SYSCALL_64(nr, sym)
 
diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl
index 0d0667a9fbd7..e6a8bec0d6a5 100644
--- a/arch/x86/entry/syscalls/syscall_32.tbl
+++ b/arch/x86/entry/syscalls/syscall_32.tbl
@@ -286,7 +286,7 @@
 272	i386	fadvise64_64		sys_ia32_fadvise64_64
 273	i386	vserver
 274	i386	mbind			sys_mbind
-275	i386	get_mempolicy		sys_get_mempolicy		compat_sys_get_mempolicy
+275	i386	get_mempolicy		sys_get_mempolicy
 276	i386	set_mempolicy		sys_set_mempolicy
 277	i386	mq_open			sys_mq_open			compat_sys_mq_open
 278	i386	mq_unlink		sys_mq_unlink
@@ -294,7 +294,7 @@
 280	i386	mq_timedreceive		sys_mq_timedreceive_time32
 281	i386	mq_notify		sys_mq_notify			compat_sys_mq_notify
 282	i386	mq_getsetattr		sys_mq_getsetattr		compat_sys_mq_getsetattr
-283	i386	kexec_load		sys_kexec_load			compat_sys_kexec_load
+283	i386	kexec_load		sys_kexec_load
 284	i386	waitid			sys_waitid			compat_sys_waitid
 # 285 sys_setaltroot
 286	i386	add_key			sys_add_key
@@ -328,7 +328,7 @@
 314	i386	sync_file_range		sys_ia32_sync_file_range
 315	i386	tee			sys_tee
 316	i386	vmsplice		sys_vmsplice
-317	i386	move_pages		sys_move_pages			compat_sys_move_pages
+317	i386	move_pages		sys_move_pages
 318	i386	getcpu			sys_getcpu
 319	i386	epoll_pwait		sys_epoll_pwait
 320	i386	utimensat		sys_utimensat_time32
diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl
index 1f47e24fb65c..930fe4821fe8 100644
--- a/arch/x86/entry/syscalls/syscall_64.tbl
+++ b/arch/x86/entry/syscalls/syscall_64.tbl
@@ -385,12 +385,12 @@
 525	x32	sigaltstack		compat_sys_sigaltstack
 526	x32	timer_create		compat_sys_timer_create
 527	x32	mq_notify		compat_sys_mq_notify
-528	x32	kexec_load		compat_sys_kexec_load
+528	x32	kexec_load		sys_kexec_load
 529	x32	waitid			compat_sys_waitid
 530	x32	set_robust_list		compat_sys_set_robust_list
 531	x32	get_robust_list		compat_sys_get_robust_list
 532	x32	vmsplice		sys_vmsplice
-533	x32	move_pages		compat_sys_move_pages
+533	x32	move_pages		sys_move_pages
 534	x32	preadv			compat_sys_preadv64
 535	x32	pwritev			compat_sys_pwritev64
 536	x32	rt_tgsigqueueinfo	compat_sys_rt_tgsigqueueinfo
diff --git a/include/linux/compat.h b/include/linux/compat.h
index cd306889b35c..47496c5eb5eb 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -623,12 +623,6 @@ asmlinkage long compat_sys_setitimer(int which,
 				     struct old_itimerval32 __user *in,
 				     struct old_itimerval32 __user *out);
 
-/* kernel/kexec.c */
-asmlinkage long compat_sys_kexec_load(compat_ulong_t entry,
-				      compat_ulong_t nr_segments,
-				      struct compat_kexec_segment __user *,
-				      compat_ulong_t flags);
-
 /* kernel/posix-timers.c */
 asmlinkage long compat_sys_timer_create(clockid_t which_clock,
 			struct compat_sigevent __user *timer_event_spec,
@@ -735,26 +729,6 @@ asmlinkage long compat_sys_execve(const char __user *filename, const compat_uptr
 /* mm/fadvise.c: No generic prototype for fadvise64_64 */
 
 /* mm/, CONFIG_MMU only */
-asmlinkage long compat_sys_mbind(compat_ulong_t start, compat_ulong_t len,
-				 compat_ulong_t mode,
-				 compat_ulong_t __user *nmask,
-				 compat_ulong_t maxnode, compat_ulong_t flags);
-asmlinkage long compat_sys_get_mempolicy(int __user *policy,
-					 compat_ulong_t __user *nmask,
-					 compat_ulong_t maxnode,
-					 compat_ulong_t addr,
-					 compat_ulong_t flags);
-asmlinkage long compat_sys_set_mempolicy(int mode, compat_ulong_t __user *nmask,
-					 compat_ulong_t maxnode);
-asmlinkage long compat_sys_migrate_pages(compat_pid_t pid,
-		compat_ulong_t maxnode, const compat_ulong_t __user *old_nodes,
-		const compat_ulong_t __user *new_nodes);
-asmlinkage long compat_sys_move_pages(pid_t pid, compat_ulong_t nr_pages,
-				      __u32 __user *pages,
-				      const int __user *nodes,
-				      int __user *status,
-				      int flags);
-
 asmlinkage long compat_sys_rt_tgsigqueueinfo(compat_pid_t tgid,
 					compat_pid_t pid, int sig,
 					struct compat_siginfo __user *uinfo);
diff --git a/include/uapi/asm-generic/unistd.h b/include/uapi/asm-generic/unistd.h
index 2056318988f7..2e9662aa1194 100644
--- a/include/uapi/asm-generic/unistd.h
+++ b/include/uapi/asm-generic/unistd.h
@@ -342,7 +342,7 @@ __SC_COMP(__NR_setitimer, sys_setitimer, compat_sys_setitimer)
 
 /* kernel/kexec.c */
 #define __NR_kexec_load 104
-__SC_COMP(__NR_kexec_load, sys_kexec_load, compat_sys_kexec_load)
+__SYSCALL(__NR_kexec_load, sys_kexec_load)
 
 /* kernel/module.c */
 #define __NR_init_module 105
@@ -673,15 +673,15 @@ __SYSCALL(__NR_madvise, sys_madvise)
 #define __NR_remap_file_pages 234
 __SYSCALL(__NR_remap_file_pages, sys_remap_file_pages)
 #define __NR_mbind 235
-__SC_COMP(__NR_mbind, sys_mbind, compat_sys_mbind)
+__SYSCALL(__NR_mbind, sys_mbind)
 #define __NR_get_mempolicy 236
-__SC_COMP(__NR_get_mempolicy, sys_get_mempolicy, compat_sys_get_mempolicy)
+__SYSCALL(__NR_get_mempolicy, sys_get_mempolicy)
 #define __NR_set_mempolicy 237
-__SC_COMP(__NR_set_mempolicy, sys_set_mempolicy, compat_sys_set_mempolicy)
+__SYSCALL(__NR_set_mempolicy, sys_set_mempolicy)
 #define __NR_migrate_pages 238
-__SC_COMP(__NR_migrate_pages, sys_migrate_pages, compat_sys_migrate_pages)
+__SYSCALL(__NR_migrate_pages, sys_migrate_pages)
 #define __NR_move_pages 239
-__SC_COMP(__NR_move_pages, sys_move_pages, compat_sys_move_pages)
+__SYSCALL(__NR_move_pages, sys_move_pages)
 #endif
 
 #define __NR_rt_tgsigqueueinfo 240
diff --git a/kernel/kexec.c b/kernel/kexec.c
index ec04791eea3e..07a5d089ead0 100644
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -258,9 +258,8 @@ static inline int kexec_load_check(unsigned long nr_segments,
 	return 0;
 }
 
-static int kernel_kexec_load(unsigned long entry, unsigned long nr_segments,
-			     struct kexec_segment __user * segments,
-			     unsigned long flags)
+SYSCALL_DEFINE4(kexec_load, unsigned long, entry, unsigned long, nr_segments,
+		struct kexec_segment __user *, segments, unsigned long, flags)
 {
 	int result;
 
@@ -290,21 +289,3 @@ static int kernel_kexec_load(unsigned long entry, unsigned long nr_segments,
 
 	return result;
 }
-
-SYSCALL_DEFINE4(kexec_load, unsigned long, entry, unsigned long, nr_segments,
-		struct kexec_segment __user *, segments, unsigned long, flags)
-{
-	return kernel_kexec_load(entry, nr_segments, segments, flags);
-}
-
-#ifdef CONFIG_COMPAT
-COMPAT_SYSCALL_DEFINE4(kexec_load, compat_ulong_t, entry,
-		       compat_ulong_t, nr_segments,
-		       struct compat_kexec_segment __user *, segments,
-		       compat_ulong_t, flags)
-{
-	return kernel_kexec_load(entry, nr_segments,
-				 (struct kexec_segment __user *)segments,
-				 flags);
-}
-#endif
diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c
index f27ac94d5fa7..4d8c314b061f 100644
--- a/kernel/sys_ni.c
+++ b/kernel/sys_ni.c
@@ -283,15 +283,10 @@ COND_SYSCALL(madvise);
 COND_SYSCALL(process_madvise);
 COND_SYSCALL(remap_file_pages);
 COND_SYSCALL(mbind);
-COND_SYSCALL_COMPAT(mbind);
 COND_SYSCALL(get_mempolicy);
-COND_SYSCALL_COMPAT(get_mempolicy);
 COND_SYSCALL(set_mempolicy);
-COND_SYSCALL_COMPAT(set_mempolicy);
 COND_SYSCALL(migrate_pages);
-COND_SYSCALL_COMPAT(migrate_pages);
 COND_SYSCALL(move_pages);
-COND_SYSCALL_COMPAT(move_pages);
 
 COND_SYSCALL(perf_event_open);
 COND_SYSCALL(accept4);
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index fb5e533667f6..ffe789c24773 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -1643,43 +1643,6 @@ SYSCALL_DEFINE5(get_mempolicy, int __user *, policy,
 	return kernel_get_mempolicy(policy, nmask, maxnode, addr, flags);
 }
 
-#ifdef CONFIG_COMPAT
-
-COMPAT_SYSCALL_DEFINE5(get_mempolicy, int __user *, policy,
-		       compat_ulong_t __user *, nmask,
-		       compat_ulong_t, maxnode,
-		       compat_ulong_t, addr, compat_ulong_t, flags)
-{
-	return kernel_get_mempolicy(policy, (unsigned long __user *)nmask,
-				    maxnode, addr, flags);
-}
-
-COMPAT_SYSCALL_DEFINE3(set_mempolicy, int, mode, compat_ulong_t __user *, nmask,
-		       compat_ulong_t, maxnode)
-{
-	return kernel_set_mempolicy(mode, (unsigned long __user *)nmask, maxnode);
-}
-
-COMPAT_SYSCALL_DEFINE6(mbind, compat_ulong_t, start, compat_ulong_t, len,
-		       compat_ulong_t, mode, compat_ulong_t __user *, nmask,
-		       compat_ulong_t, maxnode, compat_ulong_t, flags)
-{
-	return kernel_mbind(start, len, mode, (unsigned long __user *)nmask,
-			    maxnode, flags);
-}
-
-COMPAT_SYSCALL_DEFINE4(migrate_pages, compat_pid_t, pid,
-		       compat_ulong_t, maxnode,
-		       const compat_ulong_t __user *, old_nodes,
-		       const compat_ulong_t __user *, new_nodes)
-{
-	return kernel_migrate_pages(pid, maxnode,
-				    (const unsigned long __user *)old_nodes,
-				    (const unsigned long __user *)new_nodes);
-}
-
-#endif /* CONFIG_COMPAT */
-
 bool vma_migratable(struct vm_area_struct *vma)
 {
 	if (vma->vm_flags & (VM_IO | VM_PFNMAP))
diff --git a/mm/migrate.c b/mm/migrate.c
index 016e39809ca5..6ba240012b08 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1977,19 +1977,6 @@ SYSCALL_DEFINE6(move_pages, pid_t, pid, unsigned long, nr_pages,
 	return kernel_move_pages(pid, nr_pages, pages, nodes, status, flags);
 }
 
-#ifdef CONFIG_COMPAT
-COMPAT_SYSCALL_DEFINE6(move_pages, pid_t, pid, compat_ulong_t, nr_pages,
-		       compat_uptr_t __user *, pages,
-		       const int __user *, nodes,
-		       int __user *, status,
-		       int, flags)
-{
-	return kernel_move_pages(pid, nr_pages,
-				 (const void __user *__user *)pages,
-				 nodes, status, flags);
-}
-#endif /* CONFIG_COMPAT */
-
 #ifdef CONFIG_NUMA_BALANCING
 /*
  * Returns true if this is a safe migration target node for misplaced NUMA
-- 
2.27.0

Re: [PATCH v2 1/4] kexec: simplify compat_sys_kexec_load

[Christoph Hellwig]

> +	for (i=0; i < nr_segments; i++) {

Missing spaces around the "=".

> +SYSCALL_DEFINE4(kexec_load, unsigned long, entry, unsigned long, nr_segments,
> +		struct kexec_segment __user *, segments, unsigned long, flags)
> +{
> +	return kernel_kexec_load(entry, nr_segments, segments, flags);
> +}
> +
>  #ifdef CONFIG_COMPAT
>  COMPAT_SYSCALL_DEFINE4(kexec_load, compat_ulong_t, entry,
>  		       compat_ulong_t, nr_segments,
>  		       struct compat_kexec_segment __user *, segments,
>  		       compat_ulong_t, flags)
>  {
> +	return kernel_kexec_load(entry, nr_segments,
> +				 (struct kexec_segment __user *)segments,
> +				 flags);
>  }

I don't think we need sys_compat_kexec_load at all now, all the syscall
tables can simply switch to sys_kexec_load for the compat case as well
now.

Re: [PATCH v2 2/4] mm: simplify compat_sys_move_pages

[Christoph Hellwig]

>  #ifdef CONFIG_COMPAT
>  COMPAT_SYSCALL_DEFINE6(move_pages, pid_t, pid, compat_ulong_t, nr_pages,
> +		       compat_uptr_t __user *, pages,
>  		       const int __user *, nodes,
>  		       int __user *, status,
>  		       int, flags)
>  {
> +	return kernel_move_pages(pid, nr_pages,
> +				 (const void __user *__user *)pages,
> +				 nodes, status, flags);
>  }

Same as for kexec - all the compat syscall tables can just point to
the native version now.

Re: [PATCH v2 4/4] compat: remove some compat entry points

[Christoph Hellwig]

On Mon, Nov 02, 2020 at 01:31:51PM +0100, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@arndb.de>
> 
> These are all handled correctly when calling the native
> system call entry point, so remove the special cases.

Ok, this is where you do it.  I think this belongs into the main
patches.

Re: [PATCH v2 4/4] compat: remove some compat entry points

[Arnd Bergmann]

On Tue, Nov 3, 2020 at 9:38 AM Christoph Hellwig <hch@infradead.org> wrote:
>
> On Mon, Nov 02, 2020 at 01:31:51PM +0100, Arnd Bergmann wrote:
> > From: Arnd Bergmann <arnd@arndb.de>
> >
> > These are all handled correctly when calling the native
> > system call entry point, so remove the special cases.
>
> Ok, this is where you do it.  I think this belongs into the main
> patches.

I had it there originally, I guess I should have left it there ;-)

When I changed it, I was considering to do the same for additional
syscalls that have very small differences now (timer_create,
rt_sigqueueinfo, rt_sigpending, recvmsg, sendmsg) and use
in_compat_syscall() there, but then I decided against that.

In the end, I did like the split, as I found the smaller three
patches that contain the real change easier to review, and
it turns the larger patch at the end into a more obvious
transformation.

      Arnd

Re: [PATCH v2 4/4] compat: remove some compat entry points

[Christoph Hellwig]

On Tue, Nov 03, 2020 at 10:45:54AM +0100, Arnd Bergmann wrote:
> I had it there originally, I guess I should have left it there ;-)
> 
> When I changed it, I was considering to do the same for additional
> syscalls that have very small differences now (timer_create,
> rt_sigqueueinfo, rt_sigpending, recvmsg, sendmsg) and use
> in_compat_syscall() there, but then I decided against that.
> 
> In the end, I did like the split, as I found the smaller three
> patches that contain the real change easier to review, and
> it turns the larger patch at the end into a more obvious
> transformation.

Oh well, let's just keep the split as-is then.