Grant Likely schrieb:

On Tue, Aug 31, 2010 at 10:16 AM, Vasiliy Kulikov [off-list ref] wrote:

quoted

On Tue, Aug 31, 2010 at 18:08 +0200, Julia Lawall wrote:

quoted

On Tue, 31 Aug 2010, walter harms wrote:

quoted

quoted

  if (strncmp(model, "PowerBook", strlen("PowerBook")) != 0 &&
      strncmp(model, "iBook", strlen("iBook")) != 0 &&
      strcmp(model, "PowerMac7,2") != 0 &&

is there any rule that says when to use strncmp ? it seems perfecly valid to use strcpy here
(what is done in the last cmp).

Perhaps there are some characters after eg PowerBook that one doesn't want
to compare with?

It seems to me that model has no '\0' in the end. If model is got from
the hardware then we should double check it - maybe harware is buggy.
Otherwise we'll overflow model.

Model does have \0 at the end.  This code is using strncmp to
purposefully ignore the model suffix.

quoted

But why strcmp(model, "PowerMac7,2")? IMO it should be replaced
with strncmp().

We use strcmp when parsing the device tree because the the length of
the model property string is unknown and in most cases we *must* match
the exact entire string, such as with this PowerMac7,2 example.  Using
strncmp would also happen to match with something like
"PowerMac7,2345" which is not the desired behaviour.

hi Grant,
whould you mind to use you explanation as comment in the code ?
Tthat the strncpy/strcpy difference is important should be noted. that would be clearly a
bonos with further audits.

re,
 wh