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-rw-r--r--include/linux/compat.h17
-rw-r--r--mm/mempolicy.c176
2 files changed, 64 insertions, 129 deletions
diff --git a/include/linux/compat.h b/include/linux/compat.h
index 8e0598c7d1d1..3a2ac5afee30 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -395,14 +395,6 @@ struct compat_kexec_segment;
struct compat_mq_attr;
struct compat_msgbuf;
-#define BITS_PER_COMPAT_LONG (8*sizeof(compat_long_t))
-
-#define BITS_TO_COMPAT_LONGS(bits) DIV_ROUND_UP(bits, BITS_PER_COMPAT_LONG)
-
-long compat_get_bitmap(unsigned long *mask, const compat_ulong_t __user *umask,
- unsigned long bitmap_size);
-long compat_put_bitmap(compat_ulong_t __user *umask, unsigned long *mask,
- unsigned long bitmap_size);
void copy_siginfo_to_external32(struct compat_siginfo *to,
const struct kernel_siginfo *from);
int copy_siginfo_from_user32(kernel_siginfo_t *to,
@@ -976,6 +968,15 @@ static inline bool in_compat_syscall(void) { return false; }
#endif /* CONFIG_COMPAT */
+#define BITS_PER_COMPAT_LONG (8*sizeof(compat_long_t))
+
+#define BITS_TO_COMPAT_LONGS(bits) DIV_ROUND_UP(bits, BITS_PER_COMPAT_LONG)
+
+long compat_get_bitmap(unsigned long *mask, const compat_ulong_t __user *umask,
+ unsigned long bitmap_size);
+long compat_put_bitmap(compat_ulong_t __user *umask, unsigned long *mask,
+ unsigned long bitmap_size);
+
/*
* Some legacy ABIs like the i386 one use less than natural alignment for 64-bit
* types, and will need special compat treatment for that. Most architectures
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 5e90b3fb7794..eb95578f5997 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -1362,16 +1362,33 @@ mpol_out:
/*
* 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)
@@ -1379,49 +1396,29 @@ 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 */
@@ -1430,6 +1427,10 @@ 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)
@@ -1437,7 +1438,13 @@ static int copy_nodes_to_user(unsigned long __user *mask, unsigned long maxnode,
if (clear_user((char __user *)mask + nbytes, copy - nbytes))
return -EFAULT;
copy = nbytes;
+ maxnode = nr_node_ids;
}
+
+ 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;
}
@@ -1649,72 +1656,22 @@ 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,
@@ -1722,32 +1679,9 @@ 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 */