Commit Graph

4 Commits

Author SHA1 Message Date
Anna Zaks
e0c03cab58 [analyzer] Malloc: A pointer might escape through CFContainers APIs,
funopen, setvbuf.

Teach the checker and the engine about these APIs to resolve malloc
false positives. As I am adding more of these APIs, it is clear that all
this should be factored out into a separate callback (for example,
region escapes). Malloc, KeyChainAPI and RetainRelease checkers could
all use it.

llvm-svn: 151737
2012-02-29 18:42:47 +00:00
Anna Zaks
07de9c12f3 [analyzer] Invalidate the region passed to pthread_setspecific() call.
Make this call an exception in ExprEngine::invalidateArguments:
'int pthread_setspecific(ptheread_key k, const void *)' stores
a value into thread local storage. The value can later be retrieved
with 'void *ptheread_getspecific(pthread_key)'. So even thought the
parameter is 'const void *', the region escapes through the
call.

(Here we just blacklist the call in the ExprEngine's default
logic. Another option would be to add a checker which evaluates
the call and triggers the call to invalidate regions.)

Teach the Malloc Checker, which treats all system calls as safe about
the API.

llvm-svn: 151220
2012-02-23 01:05:27 +00:00
Anna Zaks
41b84847bf [analyzer] Malloc Checker: reduce false negatives rate by assuming that
a pointer cannot escape through calls to system functions. Also, stop
after reporting the first use-after-free.

llvm-svn: 150315
2012-02-11 23:46:36 +00:00
Anna Zaks
8158ef0dec [analyzer] Be less pessimistic about invalidation of global variables
as a result of a call.

Problem:
Global variables, which come in from system libraries should not be
invalidated by all calls. Also, non-system globals should not be
invalidated by system calls.

Solution:
The following solution to invalidation of globals seems flexible enough
for taint (does not invalidate stdin) and should not lead to too
many false positives. We split globals into 3 classes:

* immutable - values are preserved by calls (unless the specific
global is passed in as a parameter):
     A :  Most system globals and const scalars

* invalidated by functions defined in system headers:
     B: errno

* invalidated by all other functions (note, these functions may in
turn contain system calls):
     B: errno
     C: all other globals (which are not in A nor B)

llvm-svn: 147569
2012-01-04 23:54:01 +00:00