Add support for symbol name remapping

2 files changed, 105 insertions, 2 deletions

diff --git a/tests/Makefile.am b/tests/Makefile.am
index 9d36645..4a08c14 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -45,7 +45,9 @@ src_TESTS = \
   add-debug-tag.sh \
   empty-note.sh \
   print-execstack.sh \
-  modify-execstack.sh
+  modify-execstack.sh \
+  rename-dynamic-symbols.sh \
+  empty-note.sh
 
 build_TESTS = \
   $(no_rpath_arch_TESTS)
@@ -116,7 +118,7 @@ check_DATA = libbig-dynstr.debug
 # - with libtool, it is difficult to control options
 # - with libtool, it is not possible to compile convenience *dynamic* libraries :-(
 check_PROGRAMS += libfoo.so libfoo-scoped.so libbar.so libbar-scoped.so libsimple.so libsimple-execstack.so libbuildid.so libtoomanystrtab.so \
-                  phdr-corruption.so
+                  phdr-corruption.so many-syms-main libmany-syms.so
 
 libbuildid_so_SOURCES = simple.c
 libbuildid_so_LDFLAGS = $(LDFLAGS_sharedlib) -Wl,--build-id
@@ -147,6 +149,14 @@ too_many_strtab_SOURCES = too-many-strtab.c too-many-strtab2.s
 libtoomanystrtab_so_SOURCES = too-many-strtab.c too-many-strtab2.s
 libtoomanystrtab_so_LDFLAGS = $(LDFLAGS_sharedlib)
 
+many_syms_main_SOURCES = many-syms-main.c 
+many_syms_main_LDFLAGS = $(LDFLAGS_local) 
+many_syms_main_LDADD = -lmany-syms $(AM_LDADD)
+many_syms_main_DEPENDENCIES = libmany-syms.so
+many_syms_main_CFLAGS = -pie
+libmany_syms_so_SOURCES = many-syms.c
+libmany_syms_so_LDFLAGS = $(LDFLAGS_sharedlib)
+
 no_rpath_SOURCES = no-rpath.c
 # no -fpic for no-rpath.o
 no_rpath_CFLAGS =
@@ -158,3 +168,12 @@ contiguous_note_sections_CFLAGS = -pie
 phdr_corruption_so_SOURCES = void.c phdr-corruption.ld
 phdr_corruption_so_LDFLAGS = -nostdlib -shared -Wl,-T$(srcdir)/phdr-corruption.ld
 phdr_corruption_so_CFLAGS =
+
+many-syms.c:
+	i=1; while [ $$i -le 2000 ]; do echo "void f$$i() {};"; i=$$(($$i + 1)); done > $@
+
+many-syms-main.c:
+	echo "int main() {" > $@
+	i=1; while [ $$i -le 2000 ]; do echo "void f$$i(); f$$i();"; i=$$(($$i + 1)); done >> $@
+	echo "}" >> $@
+
diff --git a/tests/rename-dynamic-symbols.sh b/tests/rename-dynamic-symbols.sh
new file mode 100755
index 0000000..6fabb33
--- /dev/null
+++ b/tests/rename-dynamic-symbols.sh
@@ -0,0 +1,84 @@
+#!/bin/sh -e
+SCRATCH=scratch/$(basename $0 .sh)
+PATCHELF=$(readlink -f "../src/patchelf")
+
+rm -rf ${SCRATCH}
+mkdir -p ${SCRATCH}
+
+full_main_name="${PWD}/many-syms-main"
+full_lib_name="${PWD}/libmany-syms.so"
+chmod -w $full_lib_name $full_main_name
+
+suffix="_special_suffix"
+
+cd ${SCRATCH}
+
+###############################################################################
+# Test that all symbols in the dynamic symbol table will have the expected
+# names after renaming.
+# Also test that if we rename all symbols back, the symbols are as expected
+###############################################################################
+
+list_symbols() {
+    nm -D $@ | awk '{ print $NF }' | sed '/^ *$/d'
+}
+
+list_symbols $full_lib_name | cut -d@ -f1 | sort -u | awk "{printf \"%s %s${suffix}\n\",\$1,\$1}" > map
+list_symbols $full_lib_name | cut -d@ -f1 | sort -u | awk "{printf \"%s${suffix} %s\n\",\$1,\$1}" > rmap
+
+${PATCHELF} --rename-dynamic-symbols map --output libmapped.so $full_lib_name
+${PATCHELF} --rename-dynamic-symbols rmap --output libreversed.so libmapped.so
+
+list_symbols $full_lib_name | sort > orig_syms
+list_symbols libmapped.so | sort > map_syms
+list_symbols libreversed.so | sort > rev_syms
+
+diff orig_syms rev_syms > diff_orig_syms_rev_syms || exit 1
+
+# Renamed symbols that match version numbers will be printed with version instead of them being ommited
+#     CXXABI10 is printed as CXXABI10
+# but CXXABI10_renamed is printed as CXXABI10_renamed@@CXXABI10
+# awk is used to remove these cases so that we can match the "mapped" symbols to original symbols
+sed "s/${suffix}//" map_syms | awk -F @ '{ if ($1 == $2 || $1 == $3) { print $1; } else { print $0; }}' | sort > map_syms_r
+diff orig_syms map_syms_r > diff_orig_syms_map_syms_r || exit 1
+
+###############################################################################
+# Check the relocation tables after renaming
+###############################################################################
+
+print_relocation_table() {
+    readelf -W -r $1 | awk '{ printf "%s\n",$5 }' | cut -f1 -d@
+}
+
+print_relocation_table $full_lib_name > orig_rel
+print_relocation_table libmapped.so > map_rel
+print_relocation_table libreversed.so > rev_rel
+
+diff orig_rel rev_rel > diff_orig_rel_rev_rel || exit 1
+sed "s/${suffix}//" map_rel > map_rel_r
+diff orig_rel map_rel_r > diff_orig_rel_map_rel_r || exit 1
+
+###############################################################################
+# Test that the hash table is correctly updated.
+# For this to work, we need to rename symbols and actually use the library
+# Here we:
+#    1. Create a map from all symbols in libstdc++.so as "sym sym_special_suffix"
+#    2. Copy Patchelf and all of its transitive library dependencies into a new directory
+#    3. Rename symbols in Patchelf and all dependencies according to the map
+#    4. Run patchelf with the modified dependencies
+###############################################################################
+
+echo "# Create the map"
+list_symbols --defined-only $full_lib_name | cut -d@ -f1 | sort -u | awk "{printf \"%s %s${suffix}\n\",\$1,\$1}" > map
+
+echo "# Copy all dependencies"
+mkdir env
+cd env
+cp $full_lib_name $full_main_name .
+
+echo "# Apply renaming"
+chmod +w *
+${PATCHELF} --rename-dynamic-symbols ../map *
+
+echo "# Run the patched tool and libraries"
+env LD_BIND_NOW=1 LD_LIBRARY_PATH=${PWD} ./many-syms-main