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authorRoland Dreier <rolandd@cisco.com>2007-10-09 19:59:15 -0700
committerRoland Dreier <rolandd@cisco.com>2007-10-09 19:59:15 -0700
commita394f83bdfec10b09d8cb111e622556b2e6fd0de (patch)
treebc9735ed3ccda810634173f01528741cefc71a6c /drivers
parent2be8e3ee8efd6f99ce454115c29d09750915021a (diff)
IB/umad: Fix bit ordering and 32-on-64 problems on big endian systems
The declaration of struct ib_user_mad_reg_req.method_mask[] exported to userspace was an array of __u32, but the kernel internally treated it as a bitmap made up of longs. This makes a difference for 64-bit big-endian kernels, where numbering the bits in an array of__u32 gives: |31.....0|63....31|95....64|127...96| while numbering the bits in an array of longs gives: |63..............0|127............64| 64-bit userspace can handle this by just treating method_mask[] as an array of longs, but 32-bit userspace is really stuck: the meaning of the bits in method_mask[] depends on whether the kernel is 32-bit or 64-bit, and there's no sane way for userspace to know that. Fix this by updating <rdma/ib_user_mad.h> to make it clear that method_mask[] is an array of longs, and using a compat_ioctl method to convert to an array of 64-bit longs to handle the 32-on-64 problem. This fixes the interface description to match existing behavior (so working binaries continue to work) in almost all situations, and gives consistent semantics in the case of 32-bit userspace that can run on either a 32-bit or 64-bit kernel, so that the same binary can work for both 32-on-32 and 32-on-64 systems. Signed-off-by: Roland Dreier <rolandd@cisco.com>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/infiniband/core/user_mad.c49
1 files changed, 40 insertions, 9 deletions
diff --git a/drivers/infiniband/core/user_mad.c b/drivers/infiniband/core/user_mad.c
index aee29139368..b53eac4611d 100644
--- a/drivers/infiniband/core/user_mad.c
+++ b/drivers/infiniband/core/user_mad.c
@@ -44,6 +44,7 @@
#include <linux/poll.h>
#include <linux/rwsem.h>
#include <linux/kref.h>
+#include <linux/compat.h>
#include <asm/uaccess.h>
#include <asm/semaphore.h>
@@ -607,7 +608,8 @@ static unsigned int ib_umad_poll(struct file *filp, struct poll_table_struct *wa
return mask;
}
-static int ib_umad_reg_agent(struct ib_umad_file *file, unsigned long arg)
+static int ib_umad_reg_agent(struct ib_umad_file *file, void __user *arg,
+ int compat_method_mask)
{
struct ib_user_mad_reg_req ureq;
struct ib_mad_reg_req req;
@@ -622,7 +624,7 @@ static int ib_umad_reg_agent(struct ib_umad_file *file, unsigned long arg)
goto out;
}
- if (copy_from_user(&ureq, (void __user *) arg, sizeof ureq)) {
+ if (copy_from_user(&ureq, arg, sizeof ureq)) {
ret = -EFAULT;
goto out;
}
@@ -643,8 +645,18 @@ found:
if (ureq.mgmt_class) {
req.mgmt_class = ureq.mgmt_class;
req.mgmt_class_version = ureq.mgmt_class_version;
- memcpy(req.method_mask, ureq.method_mask, sizeof req.method_mask);
- memcpy(req.oui, ureq.oui, sizeof req.oui);
+ memcpy(req.oui, ureq.oui, sizeof req.oui);
+
+ if (compat_method_mask) {
+ u32 *umm = (u32 *) ureq.method_mask;
+ int i;
+
+ for (i = 0; i < BITS_TO_LONGS(IB_MGMT_MAX_METHODS); ++i)
+ req.method_mask[i] =
+ umm[i * 2] | ((u64) umm[i * 2 + 1] << 32);
+ } else
+ memcpy(req.method_mask, ureq.method_mask,
+ sizeof req.method_mask);
}
agent = ib_register_mad_agent(file->port->ib_dev, file->port->port_num,
@@ -682,13 +694,13 @@ out:
return ret;
}
-static int ib_umad_unreg_agent(struct ib_umad_file *file, unsigned long arg)
+static int ib_umad_unreg_agent(struct ib_umad_file *file, u32 __user *arg)
{
struct ib_mad_agent *agent = NULL;
u32 id;
int ret = 0;
- if (get_user(id, (u32 __user *) arg))
+ if (get_user(id, arg))
return -EFAULT;
down_write(&file->port->mutex);
@@ -729,9 +741,9 @@ static long ib_umad_ioctl(struct file *filp, unsigned int cmd,
{
switch (cmd) {
case IB_USER_MAD_REGISTER_AGENT:
- return ib_umad_reg_agent(filp->private_data, arg);
+ return ib_umad_reg_agent(filp->private_data, (void __user *) arg, 0);
case IB_USER_MAD_UNREGISTER_AGENT:
- return ib_umad_unreg_agent(filp->private_data, arg);
+ return ib_umad_unreg_agent(filp->private_data, (__u32 __user *) arg);
case IB_USER_MAD_ENABLE_PKEY:
return ib_umad_enable_pkey(filp->private_data);
default:
@@ -739,6 +751,23 @@ static long ib_umad_ioctl(struct file *filp, unsigned int cmd,
}
}
+#ifdef CONFIG_COMPAT
+static long ib_umad_compat_ioctl(struct file *filp, unsigned int cmd,
+ unsigned long arg)
+{
+ switch (cmd) {
+ case IB_USER_MAD_REGISTER_AGENT:
+ return ib_umad_reg_agent(filp->private_data, compat_ptr(arg), 1);
+ case IB_USER_MAD_UNREGISTER_AGENT:
+ return ib_umad_unreg_agent(filp->private_data, compat_ptr(arg));
+ case IB_USER_MAD_ENABLE_PKEY:
+ return ib_umad_enable_pkey(filp->private_data);
+ default:
+ return -ENOIOCTLCMD;
+ }
+}
+#endif
+
static int ib_umad_open(struct inode *inode, struct file *filp)
{
struct ib_umad_port *port;
@@ -826,7 +855,9 @@ static const struct file_operations umad_fops = {
.write = ib_umad_write,
.poll = ib_umad_poll,
.unlocked_ioctl = ib_umad_ioctl,
- .compat_ioctl = ib_umad_ioctl,
+#ifdef CONFIG_COMPAT
+ .compat_ioctl = ib_umad_compat_ioctl,
+#endif
.open = ib_umad_open,
.release = ib_umad_close
};