strip, unstrip: Handle SHT_GROUP correctly.

The usage of annobin in Fedora showed a couple of bugs when using
eu-strip and eu-unstrip on ET_REL files that contain multiple group
sections.

When stripping we should not remove the SHF_GROUP flag from sections
even if the group section itself might be removed. Either the section
itself gets removed, and so the flag doesn't matter. Or it gets moved
together with the group section into the debug file, and then it still
needs to have the flag set. Also we would "renumber" the section group
flag field (which isn't a section index, and so shouldn't be changed).

Often the group sections have the exact same name (".group"), flags
(none) and sometimes the same sizes. Which makes matching them hard.
Extract the group signature and compare those when comparing two
group sections.

Signed-off-by: Mark Wielaard <[email protected]>

1 files changed, 33 insertions, 0 deletions

diff --git a/tests/run-annobingroup.sh b/tests/run-annobingroup.sh
index 700df321..fd36e4ac 100755
--- a/tests/run-annobingroup.sh
+++ b/tests/run-annobingroup.sh
@@ -120,4 +120,37 @@ EOF
 
 testrun ${abs_top_builddir}/src/elfcmp testfile-annobingroup-i386.o remerged.elf
 
+# echo "void * foo (void) { return foo; }" > testfile-annobingroup-x86_64.c
+# gcc -g -O2 -fplugin=annobin -c testfile-annobingroup-x86_64.c
+testfiles testfile-annobingroup-x86_64.o
+
+testrun_compare ${abs_top_builddir}/src/readelf -g testfile-annobingroup-x86_64.o << EOF
+
+Section group [ 1] '.group' with signature '.text.hot.group' contains 3 entries:
+  [11] .text.hot
+  [12] .gnu.build.attributes.hot
+  [13] .rela.gnu.build.attributes.hot
+
+Section group [ 2] '.group' with signature '.text.unlikely.group' contains 3 entries:
+  [14] .text.unlikely
+  [15] .gnu.build.attributes.unlikely
+  [16] .rela.gnu.build.attributes.unlikely
+
+Section group [ 3] '.group' with signature '.text.hot..group' contains 1 entry:
+  [26] .text.hot
+
+Section group [ 4] '.group' with signature '.text.unlikely..group' contains 1 entry:
+  [27] .text.unlikely
+EOF
+
+testrun ${abs_top_builddir}/src/strip -o stripped.elf -f debugfile.elf testfile-annobingroup-x86_64.o
+
+# This would/should work, except for the unknown NOTEs.
+# testrun ${abs_top_builddir}/src/elflint --gnu stripped.elf
+# testrun ${abs_top_builddir}/src/elflint --gnu --debug debugfile.elf
+
+testrun ${abs_top_builddir}/src/unstrip -o remerged.elf stripped.elf debugfile.elf
+
+testrun ${abs_top_builddir}/src/elfcmp testfile-annobingroup-x86_64.o remerged.elf
+
 exit 0