Re: [Fwd: Re: apr_brigade_create() produces a corrupt brigade]
Ruediger Pluem wrote: This runs fine - a brigade is created, containing a single bucket. The trouble is, the bucket inside the brigade is corrupt - it's name consists of random bytes, and the pointers to its methods are either Maybe stupid thought, but isn't this bucket the sentinel and doesn't APR_BRIGADE_EMPTY return true on this brigade? There definitely was one bucket in the new empty brigade, and it makes sense that this bucket was the sentinel. What didn't make sense though was that most of the fields in this bucket were uninitialised, so the jump table for code that implements the various bucket methods consisted of bogus addresses. Regards, Graham -- smime.p7s Description: S/MIME Cryptographic Signature
Re: [Fwd: Re: apr_brigade_create() produces a corrupt brigade]
On 10/29/2006 01:59 PM, Graham Leggett wrote: Ruediger Pluem wrote: This runs fine - a brigade is created, containing a single bucket. The trouble is, the bucket inside the brigade is corrupt - it's name consists of random bytes, and the pointers to its methods are either Maybe stupid thought, but isn't this bucket the sentinel and doesn't APR_BRIGADE_EMPTY return true on this brigade? There definitely was one bucket in the new empty brigade, and it makes sense that this bucket was the sentinel. What didn't make sense though was that most of the fields in this bucket were uninitialised, so the jump table for code that implements the various bucket methods consisted of bogus addresses. Just two curious questions: 1. Did APR_BRIGADE_EMPTY return true on this newly created brigade? 2. Shouldn't the code take care never to process the sentinel because of the problems you pointed out above (invalid data, especially in the jump table)? Regards Rüdiger
Re: [Fwd: Re: apr_brigade_create() produces a corrupt brigade]
Ruediger Pluem wrote: Just two curious questions: 1. Did APR_BRIGADE_EMPTY return true on this newly created brigade? No idea, didn't try it. 2. Shouldn't the code take care never to process the sentinel because of the problems you pointed out above (invalid data, especially in the jump table)? Which code, apr or the client code? In the case of the client code, it shouldn't have to take care about anything - if an entry in the jump table is unimplemented for any reason, it should be initialised to NULL, and attempts to call those methods should return APR_ENOTIMPL. At the moment, no clean error occurs, as the code falls of the rails and eventually crashes randomly later on. Regards, Graham -- smime.p7s Description: S/MIME Cryptographic Signature
Re: [Fwd: Re: apr_brigade_create() produces a corrupt brigade]
On 10/29/2006 03:53 PM, Graham Leggett wrote: Ruediger Pluem wrote: Just two curious questions: 1. Did APR_BRIGADE_EMPTY return true on this newly created brigade? No idea, didn't try it. 2. Shouldn't the code take care never to process the sentinel because of the problems you pointed out above (invalid data, especially in the jump table)? Which code, apr or the client code? Client code. In the case of the client code, it shouldn't have to take care about anything - if an entry in the jump table is unimplemented for any reason, it should be initialised to NULL, and attempts to call those methods should return APR_ENOTIMPL. At the moment, no clean error occurs, as the code falls of the rails and eventually crashes randomly later on. This sounds reasonable. At least this produces reliable error situations in the case you use the sentinel by error and make things much easier to debug. Guess that needs to be fixed inside of apr-util. Regards Rüdiger
