Bug 1284019

Summary:	libselinux: Move rpm_execcon to separate library
Product:	[Fedora] Fedora	Reporter:	Florian Weimer <fweimer>
Component:	libselinux	Assignee:	Petr Lautrbach <plautrba>
Status:	CLOSED RAWHIDE	QA Contact:	Fedora Extras Quality Assurance <extras-qa>
Severity:	unspecified	Docs Contact:
Priority:	unspecified
Version:	rawhide	CC:	dwalsh, mgrepl, plautrba
Target Milestone:	---	Keywords:	FutureFeature
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:	libselinux-2.4-6.fc24	Doc Type:	Enhancement
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2015-12-10 18:07:26 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description Florian Weimer 2015-11-20 14:57:01 UTC

Would it be possible to move rpm_execcon and its execve call to a separate library?  A linker script could preserve link-time compatibility with build environments of dependencies.

Background: We are investigating if it is possible to remove execve call sites from most processes, and that execve inside libselinux is one very prominent supplier of execve, due to rpm_execcon.

Comment 1 Petr Lautrbach 2015-11-20 16:46:57 UTC

I believe we could build libselinux without rpm_execcon completely:

--- a/libselinux.spec
+++ b/libselinux.spec
@@ -106,6 +106,7 @@ needed for developing SELinux applications.
 
 %build
 export LDFLAGS="%{?__global_ldflags}"
+export DISABLE_RPM="y"
 
 # To support building the Python wrapper against multiple Python runtimes
 # Define a function, for how to perform a "build" of the python wrapper against



rpm_execcon is marked as deprecated since 2012 and according to rpm's changelog, it doesn't use it any more:

commit 148e82833a384b438547c2d3610e3df4a50cf997
Author: Guillem Jover <guillem>
Date:   Thu Jan 15 17:01:48 2015 +0100

    Use setexecfilecon() from libselinux instead of ad-hoc code
    
    This function was factored out from rpm_execcon() upstream to make it
    easier to use by its users, by making it not call execve() directly. It
    is now also used by dpkg since 1.17.11.
    
    Preserve the ad-hoc code for now so that it can be compiled against old
    libselinux versions.

Comment 2 Florian Weimer 2015-11-20 19:58:55 UTC

I'm fine with removing it completely.  I checked, and there is no downstream ABI impact (at least nominally).