[apparmor] [PATCH 06/11] Ensure that all cases that resolve to nonmatching state are hashed the same

[Steve Beattie]

On Mon, Oct 18, 2010 at 05:20:38PM -0700, John Johansen wrote:
> When hashing Nodes ensure that cases.otherwise == NULL is treated the same
> as pointing to the nonmatching state.  Having this mix shouldn't currently
> exist but adding the extra check makes the code more robust.
> ---
>  parser/libapparmor_re/regexp.y |    6 +++---
>  1 files changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/parser/libapparmor_re/regexp.y b/parser/libapparmor_re/regexp.y
> index 6de7ae6..4c5d801 100644
> --- a/parser/libapparmor_re/regexp.y
> +++ b/parser/libapparmor_re/regexp.y
> @@ -1640,14 +1640,14 @@ void DFA::remove_unreachable(dfaflags_t flags)
>  bool DFA::same_mappings(map <State *, Partition *> &partition_map, State *s1,
>  			State *s2)
>  {
> -	if (s1->cases.otherwise) {
> -		if (!s2->cases.otherwise)
> +	if (s1->cases.otherwise && s1->cases.otherwise != nonmatching) {
> +		if (!s2->cases.otherwise && s2->cases.otherwise != nonmatching)

Is the logic here in the second if-statement correct? Shouldn't it be

    if (!s2->cases.otherwise || s2->cases.otherwise == nonmatching)

as you've already verified that s1->cases.otherwise is not NULL and not
a nonmatching state? Or am I missing something?

>  			return false;
>  		Partition *p1 = partition_map.find(s1->cases.otherwise)->second;
>  		Partition *p2 = partition_map.find(s2->cases.otherwise)->second;
>  		if (p1 != p2)
>  			return false;
> -	} else if (s2->cases.otherwise) {
> +	} else if (s2->cases.otherwise && s1->cases.otherwise != nonmatching) {
>  		return false;
>  	}
>  

-- 
Steve Beattie
<sbeattie at ubuntu.com>
http://NxNW.org/~steve/
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