From a394f83bdfec10b09d8cb111e622556b2e6fd0de Mon Sep 17 00:00:00 2001 From: Roland Dreier Date: Tue, 9 Oct 2007 19:59:15 -0700 Subject: 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 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 --- drivers/infiniband/core/user_mad.c | 49 +++++++++++++++++++++++++++++++------- 1 file changed, 40 insertions(+), 9 deletions(-) (limited to 'drivers/infiniband') diff --git a/drivers/infiniband/core/user_mad.c b/drivers/infiniband/core/user_mad.c index aee2913..b53eac4 100644 --- a/drivers/infiniband/core/user_mad.c +++ b/drivers/infiniband/core/user_mad.c @@ -44,6 +44,7 @@ #include #include #include +#include #include #include @@ -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 }; -- cgit v1.1