From 45b4344c56d7e6fad726b73fc407f8b75f579fe4 Mon Sep 17 00:00:00 2001
From: Josh Cooper <joshcooper@users.noreply.github.com>
Date: Thu, 19 Jan 2023 15:13:22 -0800
Subject: [PATCH] (PA-4844) Patch the autogenerated selinux C extension

Calling into selinux from Ruby 3.2 generates a warning:

    selinux.so: warning: undefining the allocator of T_DATA class swig_runtime_data

This is because ruby 3.2 requires C extensions to "either use
rb_define_alloc_func() to overwrite it or rb_undef_alloc_func() to delete
it."[1] The selinux C extension selinuxswig_ruby_wrap.c is autogenerated by swig
from the selinuxswig_i template.

swig 4.1.1 contains the fix for this[2] but we are using an older version on
RHEL7. So patch the autogenerated C extension, which needs to happen after the
code is generated and before it's compiled.

[1] https://github.com/ruby/ruby/blob/6963f8f743b42f9004a0879cd66c550f18987352/doc/extension.rdoc#label-Write+the+C+Code
[2] https://github.com/swig/swig/commit/962f0900018ecb10287b327d261e424fa5ccb755
---
 configs/components/_base-ruby-selinux.rb          | 15 ++++++++++++---
 .../ruby-selinux/selinuxswig_ruby_wrap.patch      | 10 ++++++++++
 2 files changed, 22 insertions(+), 3 deletions(-)
 create mode 100644 resources/patches/ruby-selinux/selinuxswig_ruby_wrap.patch

diff --git a/configs/components/_base-ruby-selinux.rb b/configs/components/_base-ruby-selinux.rb
index 82d314471..e13753d74 100644
--- a/configs/components/_base-ruby-selinux.rb
+++ b/configs/components/_base-ruby-selinux.rb
@@ -3,6 +3,8 @@
 # load it with instance_eval. See ruby-x.y-selinux.rb configs.
 #
 
+pkg.add_source("file://resources/patches/ruby-selinux/selinuxswig_ruby_wrap.patch")
+
 # These can be overridden by the including component.
 ruby_version ||= settings[:ruby_version]
 host_ruby ||= settings[:host_ruby]
@@ -42,16 +44,23 @@
 end
 
 pkg.build do
-  [
+  steps = [
     "export RUBYHDRDIR=$(shell #{ruby} -e 'puts RbConfig::CONFIG[\"rubyhdrdir\"]')",
     "export VENDORARCHDIR=$(shell #{ruby} -e 'puts RbConfig::CONFIG[\"vendorarchdir\"]')",
     "export ARCHDIR=$${RUBYHDRDIR}/$(shell #{ruby} -e 'puts RbConfig::CONFIG[\"arch\"]')",
     "export INCLUDESTR=\"-I#{settings[:includedir]} -I$${RUBYHDRDIR} -I$${ARCHDIR}\"",
     "cp -pr src/{selinuxswig_ruby.i,selinuxswig.i} .",
-    "swig -Wall -ruby #{system_include} -o selinuxswig_ruby_wrap.c -outdir ./ selinuxswig_ruby.i",
+    "swig -Wall -ruby #{system_include} -o selinuxswig_ruby_wrap.c -outdir ./ selinuxswig_ruby.i"
+  ]
+
+  if ruby_version =~ /^3/
+    steps << "#{platform.patch} --strip=0 --fuzz=0 --ignore-whitespace --no-backup-if-mismatch < ../selinuxswig_ruby_wrap.patch"
+  end
+
+  steps.concat([
     "#{cc} $${INCLUDESTR} #{system_include} #{cflags} -D_GNU_SOURCE -D_FILE_OFFSET_BITS=64 -fPIC -DSHARED -c -o selinuxswig_ruby_wrap.lo selinuxswig_ruby_wrap.c",
     "#{cc} $${INCLUDESTR} #{system_include} -D_GNU_SOURCE -D_FILE_OFFSET_BITS=64 -shared -o _rubyselinux.so selinuxswig_ruby_wrap.lo -lselinux -Wl,-z,relro,-z,now,-soname,_rubyselinux.so",
-  ]
+  ])
 end
 
 pkg.install do
diff --git a/resources/patches/ruby-selinux/selinuxswig_ruby_wrap.patch b/resources/patches/ruby-selinux/selinuxswig_ruby_wrap.patch
new file mode 100644
index 000000000..28b7999a5
--- /dev/null
+++ b/resources/patches/ruby-selinux/selinuxswig_ruby_wrap.patch
@@ -0,0 +1,10 @@
+--- selinuxswig_ruby_wrap.c.orig	2023-01-18 22:38:21.527547362 -0800
++++ selinuxswig_ruby_wrap.c	2023-01-18 22:38:26.887569066 -0800
+@@ -1724,6 +1724,7 @@
+ {
+   /* register a new class */
+   VALUE cl = rb_define_class("swig_runtime_data", rb_cObject);
++  rb_undef_alloc_func(cl);
+   /* create and store the structure pointer to a global variable */
+   swig_runtime_data_type_pointer = Data_Wrap_Struct(cl, 0, 0, pointer);
+   rb_define_readonly_variable("$swig_runtime_data_type_pointer" SWIG_RUNTIME_VERSION SWIG_TYPE_TABLE_NAME, &swig_runtime_data_type_pointer);