[PATCH] malloc: add locking to thread cache

[Yury Gribov]

On 01/26/2016 03:44 PM, Szabolcs Nagy wrote:
> On 26/01/16 00:25, Joern Engel wrote:
>> With signals we can reenter the thread-cache.  Protect against that with
>> a lock.  Will almost never happen in practice, it took the company five
>> years to reproduce a similar race in the existing malloc.  But easy to
>> trigger with a targeted test.
>
> why do you try to make malloc as-safe?
>
> isn't it better to fix malloc usage in signal handlers?

FYI I once tried to check OSS for violations of signal handler 
requirements (see https://github.com/yugr/sigcheck).  It turned out that 
many packages (ab)use malloc in sighandlers (directly or via printf et 
al.).  Fixing (or even finding) all badly behaving software out there 
would be a huge amount of work so "fixing" it on the library side 
instead may make sense.

-Y