[asterisk-bugs] [JIRA] (ASTERISK-26800) Non-threadsafe function usage

[Ian Gilmour (JIRA)]

Ian Gilmour created ASTERISK-26800:
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             Summary: Non-threadsafe function usage
                 Key: ASTERISK-26800
                 URL: https://issues.asterisk.org/jira/browse/ASTERISK-26800
             Project: Asterisk
          Issue Type: Bug
      Security Level: None
    Affects Versions: 13.14.0
            Reporter: Ian Gilmour


Looking through the asterisk codebase I see what (at least at first glance) appear to be use of some non-threadsafe functions. e.g. ctime, strtok, localtime, etc.

As a check I wrote a bash/cscope-based script (chkthreadsafe) that attempts to identify where non-threadsafe functions are being used.

It uses the list of potentially non-threadsafe functions from 
http://pubs.opengroup.org/onlinepubs/9699919799/functions/V2_chap02.html#tag_15_09_01.

I notice some of these functions have threadsafe equivalents but that those threadsafe equivalents are themselves now deprecated (e.g. readdir is now favoured again rather than readdir_r according to [http://man7.org/linux/man-pages/man3/readdir.3.html#ATTRIBUTES]). So is there a better list of non-threadsafe functions?

Using the current list I have the script comes up with a few entries when run against the 13.14.0 branch (see [^chkthreadsafe.output.tgz] ).

The script is far from perfect. I accept there are a lot more false positives than positives in the output at present.

False positives come from various sources:
* variables that have the same name as non-threadsafe functions, 
* functions that may only be used on a single thread during system startup/shutdown, etc.,
* and I can see asterisk has it's own threadsafe versions of some of these functions (e.g. ast_inet_ntoa, ast_crypt, etc).

But that still leaves a few calls that are potentially non-threadsafe. Some of these (e.g. strtok) have threadsafe equivalents already in use elsewhere in the code (strtok_r, etc.).

I'm just querying if the use of these functions needs further review by those that know the asterisk codebase better?




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