On 2/13/2018 12:16 PM, Jason Gunthorpe wrote:
On Tue, Feb 13, 2018 at 11:56:47AM -0500, Dennis Dalessandro wrote:
On 2/13/2018 5:18 AM, Leon Romanovsky wrote:
From: Matan Barak <matanb@xxxxxxxxxxxx>
32 bit processes running on a 64 bit kernel call compat_ioctl so that
implementations can revise any structure layout issues. Point compat_ioctl
at our normal ioctl because:
- All our structures are designed to be the same on 32 and 64 bit, ie we
use __aligned_u64 when required and are careful to manage padding.
- Any pointers are stored in u64's and userspace is expected
to prepare them properly.
Signed-off-by: Matan Barak <matanb@xxxxxxxxxxxx>
Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxxxx>
Signed-off-by: Leon Romanovsky <leon@xxxxxxxxxx>
drivers/infiniband/core/uverbs_main.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/infiniband/core/uverbs_main.c b/drivers/infiniband/core/uverbs_main.c
index 395a3b091229..cd72555ad457 100644
+++ b/drivers/infiniband/core/uverbs_main.c
@@ -942,6 +942,7 @@ static const struct file_operations uverbs_fops = {
.llseek = no_llseek,
#if IS_ENABLED(CONFIG_INFINIBAND_EXP_USER_ACCESS)
.unlocked_ioctl = ib_uverbs_ioctl,
+ .compat_ioctl = ib_uverbs_ioctl,
#endif
};
@@ -954,6 +955,7 @@ static const struct file_operations uverbs_mmap_fops = {
.llseek = no_llseek,
#if IS_ENABLED(CONFIG_INFINIBAND_EXP_USER_ACCESS)
.unlocked_ioctl = ib_uverbs_ioctl,
+ .compat_ioctl = ib_uverbs_ioctl,
#endif
};
Is this patch really necessary?
Yes. Without it 32 bit gets:
ioctl(3, _IOC(_IOC_READ|_IOC_WRITE, 0x1b, 0x1, 0x10), 0xffcaf5f8) = -1 ENOTTY (Inappropriate ioctl for device)
Doesn't sys_ioctl() just end up calling unlocked_ioctl() if
.compat_ioctl is not set? I guess nothing wrong with being explicit
here, but this is just a clean-up then, and not an -rc patch.
No, the control flow is really tortured in compat_ioctl.c, but it
will only call compat_ioctl for our case.
Ok, thanks, I'll go take another look.
-Denny
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