Bug 469908 - rpmlint warning shared-lib-calls-exit is often invalid and potentially dangerous
Summary: rpmlint warning shared-lib-calls-exit is often invalid and potentially dangerous
Keywords:
Status: CLOSED WONTFIX
Alias: None
Product: Fedora
Classification: Fedora
Component: rpmlint
Version: 9
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Ville Skyttä
QA Contact: Fedora Extras Quality Assurance
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2008-11-04 17:45 UTC by David Carter
Modified: 2009-07-14 14:56 UTC (History)
4 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
Environment:
Last Closed: 2009-07-14 14:56:13 UTC
Type: ---
Embargoed:


Attachments (Terms of Use)

Description David Carter 2008-11-04 17:45:04 UTC
Description of problem:
This is a new warning that started appearing in rpmlint about a week ago, and I'm quite disturbed by it for a number of reasons. Some cases where an exit() call in a shared library are valid design choices:

1. Panic conditions, such as failed assertions
2. Common error handlers and/or exit handlers put in a shared library

In general, the comments provided seem to be for a library providing a public API while ignoring dynamically loaded libraries used internally by an application.

It could be argued that this is just a warning, and is therefore not worth changing, but here's why I think leaving it as is is dangerous. Fixing this will always require at least an architectural review to assess the impact of changes, and often an architectural rethink. Fixes by the packager in this regard could have unintended consequences and will most surely lead to library version conflicts with the upstream version.

This is a message to the upstream developers and requiring or implying that a packager should fix it will only lead to problems. More so, reviewers may not be aware of the potential complications.

Finally, given the number of cases where this could be a valid design choice, a lot of personal resources could be dedicated to evaluating and fixing problems that aren't really problems.

At the very least, the message should be reworded to reflect these concerns.

Version-Release number of selected component (if applicable):
0.85

How reproducible: Reproducible.


Steps to Reproduce:
1. Download and install the arm4 library source:
Spec URL: http://arm4.org/Downloads/0.8-0.4/arm4.spec
SRPM URL: http://arm4.org/Downloads/0.8-0.4/arm4-0.8-0.4.fc9.src.rpm
2. build the libraries
3. run rpmlint on arm4-0.8-0.4.fc9.i386.rpm
  
Actual results:
arm4.i386: W: shared-lib-calls-exit /usr/lib/libarm4db.so.1.0.0 exit
This library package calls exit() or _exit(), probably in a non-fork()
context. Doing so from a library is strongly discouraged - when a library
function calls exit(), it prevents the calling program from handling the
error, reporting it to the user, closing files properly, and cleaning up any
state that the program has. It is preferred for the library to return an
actual error code and let the calling program decide how to handle the
situation.

... other similar warnings


Expected results:
No warning.

Additional info:

Comment 1 Ville Skyttä 2008-11-04 18:36:21 UTC
Bill, comments?  (This check was added per his request in bug 450011.)

I'm not quite convinced that this check should be ditched altogether, but I agree that a note in the info message that encourages packagers to ask upstream to fix the issue (if any) rather just go patching themselves would be a good thing to add to it.  Could you suggest a reworded info message?

Also, if there are some more ways to detect generic usage patterns for which this warning should be muted (like is currently being done for fork() and friends) without dropping the check altogether, ideas and implementations for them is very much welcome.

Comment 2 Bill Nottingham 2008-11-04 18:45:48 UTC
If it's causing this much churn, we can take it out. It's just something that might be useful to prod upstreams about fixing where it does occur, because it's bitten us in the past.

Comment 3 Ville Skyttä 2008-11-04 19:12:39 UTC
Hm, "this much churn"... this is the only bit of feedback I've heard about the check so far so I'm not quite ready to toss it out yet.

Comment 4 Bug Zapper 2009-06-10 03:10:33 UTC
This message is a reminder that Fedora 9 is nearing its end of life.
Approximately 30 (thirty) days from now Fedora will stop maintaining
and issuing updates for Fedora 9.  It is Fedora's policy to close all
bug reports from releases that are no longer maintained.  At that time
this bug will be closed as WONTFIX if it remains open with a Fedora 
'version' of '9'.

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Comment 5 Bug Zapper 2009-07-14 14:56:13 UTC
Fedora 9 changed to end-of-life (EOL) status on 2009-07-10. Fedora 9 is 
no longer maintained, which means that it will not receive any further 
security or bug fix updates. As a result we are closing this bug.

If you can reproduce this bug against a currently maintained version of 
Fedora please feel free to reopen this bug against that version.

Thank you for reporting this bug and we are sorry it could not be fixed.


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