| Submitter | Cyril Roelandt |
|---|---|
| Date | Nov. 16, 2012, 3:26 a.m. |
| Message ID | <1353036410-14439-1-git-send-email-tipecaml@gmail.com> |
| Download | mbox | patch |
| Permalink | /patch/199482/ |
| State | Awaiting Upstream |
| Delegated to: | David Miller |
| Headers | show |
Comments
On Fri, 2012-11-16 at 04:26 +0100, Cyril Roelandt wrote: > > copy_to_user() cannot return a negative value: it returns the number > of bytes > that could not be copied. > > Return -EFAULT on failure rather than the number of bytes that could > not be > copied, as this seems more standard. > > Signed-off-by: Cyril Roelandt <tipecaml@gmail.com> > --- > drivers/net/ethernet/intel/ixgbe/ixgbe_debugfs.c | 6 ++---- > 1 file changed, 2 insertions(+), 4 deletions(-) Actually, I already have a similar patch in my queue reported by Dan Carpenter, and created by Josh Hay which fixes this issue. I should be pushing the patch in my queue in the next week. Here is the patch I am referring to: ixgbe: eliminate Smatch warnings in ixgbe_debugfs.c This patch replaces calls to copy_to_user, copy_from_user, and the associated logic, with calls to simple_read_from_buffer and simple_write_to_buffer respectively. This was done to eliminate warnings generated by the Smatch static analysis tool. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> CC: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Josh Hay <joshua.a.hay@intel.com> Cheers, Jeff
Patch
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_debugfs.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_debugfs.c index 8d3a218..77a3598 100644 --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_debugfs.c +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_debugfs.c @@ -62,7 +62,6 @@ static ssize_t ixgbe_dbg_reg_ops_read(struct file *filp, char __user *buffer, { struct ixgbe_adapter *adapter = filp->private_data; char buf[256]; - int bytes_not_copied; int len; /* don't allow partial reads */ @@ -73,9 +72,8 @@ static ssize_t ixgbe_dbg_reg_ops_read(struct file *filp, char __user *buffer, adapter->netdev->name, ixgbe_dbg_reg_ops_buf); if (count < len) return -ENOSPC; - bytes_not_copied = copy_to_user(buffer, buf, len); - if (bytes_not_copied < 0) - return bytes_not_copied; + if (copy_to_user(buffer, buf, len) > 0) + return -EFAULT; *ppos = len; return len;
copy_to_user() cannot return a negative value: it returns the number of bytes that could not be copied. Return -EFAULT on failure rather than the number of bytes that could not be copied, as this seems more standard. Signed-off-by: Cyril Roelandt <tipecaml@gmail.com> --- drivers/net/ethernet/intel/ixgbe/ixgbe_debugfs.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-)