tests/rtdl: add basic rtdl tests

tests/rtdl/dl_iterate_phdr/test.c

@@ -4,7 +4,6 @@
 #include <dlfcn.h>
 #include <stdio.h>
 
-
 #ifdef USE_HOST_LIBC
 #define LDSO_PATTERN "ld-linux-"
 #define LIBFOO "libnative-foo.so"
@@ -59,33 +58,32 @@ static int callback(struct dl_phdr_info *info, size_t size, void *data) {
 
 int main() {
 	struct result found = { 0 };
-	printf("---\n");
 	assert(!dl_iterate_phdr(callback, &found));
 	assert(found.found_ldso == 1);
 	assert(found.found_self == 1);
 	assert(found.found_foo == 0);
 	assert(found.found_bar == 0);
+	printf("---\n");
 
 	memset(&found, 0, sizeof(found));
 	void *bar = dlopen(LIBBAR, RTLD_LOCAL | RTLD_NOW);
 	assert(bar);
-	printf("---\n");
 	assert(!dl_iterate_phdr(callback, &found));
 	assert(found.found_ldso == 1);
 	assert(found.found_self == 1);
-	assert(found.found_foo == 1); // Since bar depends on foo.
 	assert(found.found_bar == 1);
+	assert(found.found_foo == 1); // Since bar depends on foo.
+	printf("---\n");
 
 	memset(&found, 0, sizeof(found));
 	void *foo = dlopen(LIBFOO, RTLD_GLOBAL | RTLD_NOW);
 	assert(foo);
-	printf("---\n");
 	assert(!dl_iterate_phdr(callback, &found));
 	assert(found.found_ldso == 1);
 	assert(found.found_self == 1);
 	assert(found.found_foo == 1);
-	assert(found.found_foo > 0);
 	assert(found.found_bar == 1);
+	printf("---\n");
 
 	dlclose(bar);
 	dlclose(foo);

tests/rtdl/meson.build

@@ -1,8 +1,13 @@
 rtdl_test_cases = [
 	'dl_iterate_phdr',
+	'noload-promote',
 	'rtld_next',
 	'soname',
 	'preinit',
+	'scope1',
+	'scope2',
+	'scope3',
+	'scope4',
 ]
 
 foreach test_name : rtdl_test_cases 

tests/rtdl/noload-promote/libfoo.c

@@ -0,0 +1 @@
+void foo() {}

tests/rtdl/noload-promote/meson.build

@@ -0,0 +1,5 @@
+libfoo = shared_library('foo', 'libfoo.c')
+test_depends = [libfoo]
+
+libfoo_native = shared_library('native-foo', 'libfoo.c', native: true)
+test_native_depends = [libfoo_native]

tests/rtdl/noload-promote/test.c

@@ -0,0 +1,22 @@
+#include <dlfcn.h>
+#include <assert.h>
+#include <stddef.h>
+
+#ifdef USE_HOST_LIBC
+#define LIBFOO "libnative-foo.so"
+#else
+#define LIBFOO "libfoo.so"
+#endif
+
+int main() {
+	void *foo = dlopen(LIBFOO, RTLD_LOCAL | RTLD_NOW);
+	assert(foo);
+
+	assert(dlsym(RTLD_DEFAULT, "foo") == NULL);
+
+	// Opening a library with RTLD_NOLOAD | RTLD_GLOBAL should promote it to the global scope.
+	assert(dlopen(LIBFOO, RTLD_NOLOAD | RTLD_GLOBAL | RTLD_NOW) == foo);
+	assert(dlsym(RTLD_DEFAULT, "foo") != NULL);
+	
+	assert(dlopen("does-not-exist.so.1337", RTLD_NOLOAD | RTLD_GLOBAL | RTLD_NOW) == NULL);
+}

tests/rtdl/scope1/libbar.c

@@ -0,0 +1,14 @@
+char *foo(void);
+char *foo_global(void);
+
+char *bar() {
+	return "bar";
+}
+
+char *bar_calls_foo() {
+	return foo();
+}
+
+char *bar_calls_foo_global() {
+	return foo_global();
+}

tests/rtdl/scope1/libfoo.c

@@ -0,0 +1,9 @@
+char *foo() {
+	return "foo";
+}
+
+char global[] = "foo global";
+
+char *foo_global() {
+	return global;
+}

tests/rtdl/scope1/meson.build

@@ -0,0 +1,7 @@
+libfoo = shared_library('foo', 'libfoo.c')
+libbar = shared_library('bar', 'libbar.c', build_rpath: test_rpath, link_with: libfoo)
+test_depends = [libfoo, libbar]
+
+libfoo_native = shared_library('native-foo', 'libfoo.c', native: true)
+libbar_native = shared_library('native-bar', 'libbar.c', build_rpath: test_rpath, link_with: libfoo_native, native: true)
+test_native_depends = [libfoo_native, libbar_native]

tests/rtdl/scope1/test.c

@@ -0,0 +1,90 @@
+#include <stddef.h>
+#include <dlfcn.h>
+#include <assert.h>
+#include <string.h>
+#include <stdio.h>
+
+#ifdef USE_HOST_LIBC
+#define LIBFOO "libnative-foo.so"
+#define LIBBAR "libnative-bar.so"
+#else
+#define LIBFOO "libfoo.so"
+#define LIBBAR "libbar.so"
+#endif
+
+typedef char *strfn(void);
+
+int main() {
+	// We haven't dlopen'd these libs yet, so symbol resolution should fail.
+	assert(dlsym(RTLD_DEFAULT, "foo") == NULL);
+	assert(dlsym(RTLD_DEFAULT, "bar") == NULL);
+
+	assert(!dlopen(LIBFOO, RTLD_NOLOAD));
+	assert(!dlopen(LIBBAR, RTLD_NOLOAD));
+
+	void *foo_handle = dlopen(LIBFOO, RTLD_LOCAL | RTLD_NOW);
+	assert(foo_handle);
+	assert(dlopen(LIBFOO, RTLD_NOLOAD | RTLD_NOW));
+
+	strfn *foo_sym = dlsym(foo_handle, "foo");
+	assert(foo_sym);
+	assert(foo_sym());
+	assert(!strcmp(foo_sym(), "foo"));
+
+	strfn *foo_global_sym = dlsym(foo_handle, "foo_global");
+	assert(foo_global_sym);
+	assert(foo_global_sym());
+	assert(!strcmp(foo_global_sym(), "foo global"));
+
+	assert(dlsym(foo_handle, "doesnotexist") == NULL);
+
+	// Nested opening should work
+	assert(dlopen(LIBFOO, RTLD_LOCAL | RTLD_NOW) == foo_handle);
+	assert(dlopen(LIBFOO, RTLD_NOLOAD | RTLD_NOW));
+
+	// Since we've loaded the same library twice, the addresses should be the same
+	assert(dlsym(foo_handle, "foo") == foo_sym);
+	assert(dlsym(foo_handle, "foo_global") == foo_global_sym);
+
+	// libfoo was opened with RTLD_LOCAL, so we shouldn't be able to lookup
+	// its symbols in the global namespace.
+	assert(dlsym(RTLD_DEFAULT, "foo") == NULL);
+
+	{
+		void *bar_handle = dlopen(LIBBAR, RTLD_GLOBAL | RTLD_NOW);
+		assert(bar_handle);
+		assert(dlopen(LIBBAR, RTLD_NOLOAD | RTLD_NOW));
+		
+		strfn *bar_sym = dlsym(bar_handle, "bar");
+		assert(bar_sym);
+		assert(bar_sym());
+		assert(!strcmp(bar_sym(), "bar"));
+		
+		strfn *bar_calls_foo_sym = dlsym(bar_handle, "bar_calls_foo");
+		assert(bar_calls_foo_sym);
+		assert(bar_calls_foo_sym());
+		assert(!strcmp(bar_calls_foo_sym(), "foo"));
+		
+		strfn *bar_calls_foo_global_sym = dlsym(bar_handle, "bar_calls_foo_global");
+		assert(bar_calls_foo_global_sym);
+		assert(bar_calls_foo_global_sym());
+		assert(!strcmp(bar_calls_foo_global_sym(), "foo global"));
+
+		// libbar was opened with RTLD_GLOBAL, so we can find symbols by
+		// searching in the global scope.
+		strfn *new_bar_sym = dlsym(RTLD_DEFAULT, "bar");
+		assert(new_bar_sym);
+		assert(new_bar_sym == bar_sym);
+
+		// Note that we loaded libbar with RTLD_GLOBAL, which should pull
+		// in libfoo's symbols globally too.
+		strfn *new_foo_sym = dlsym(RTLD_DEFAULT, "foo");
+		assert(new_foo_sym);
+		assert(new_foo_sym == foo_sym);
+
+		assert(dlclose(bar_handle) == 0);
+	}
+
+	assert(dlclose(foo_handle) == 0);
+	assert(dlclose(foo_handle) == 0);
+}

tests/rtdl/scope2/libbar.c

@@ -0,0 +1,5 @@
+char *foo_baz_conflict(void);
+
+char *bar_calls_foo_baz_conflict() {
+	return foo_baz_conflict();
+}

tests/rtdl/scope2/libbaz.c

@@ -0,0 +1,3 @@
+char *foo_baz_conflict() {
+	return "resolved to baz";
+}

tests/rtdl/scope2/libfoo.c

@@ -0,0 +1,3 @@
+char *foo_baz_conflict() {
+	return "resolved to foo";
+}

tests/rtdl/scope2/meson.build

@@ -0,0 +1,9 @@
+libfoo = shared_library('foo', 'libfoo.c')
+libbar = shared_library('bar', 'libbar.c', build_rpath: test_rpath, link_with: libfoo)
+libbaz = shared_library('baz', 'libbaz.c')
+test_depends = [libfoo, libbar, libbaz]
+
+libfoo_native = shared_library('native-foo', 'libfoo.c', native: true)
+libbar_native = shared_library('native-bar', 'libbar.c', build_rpath: test_rpath, link_with: libfoo_native, native: true)
+libbaz_native = shared_library('native-baz', 'libbaz.c', native: true)
+test_native_depends = [libfoo_native, libbar_native, libbaz_native]

tests/rtdl/scope2/test.c

@@ -0,0 +1,36 @@
+#include <stddef.h>
+#include <dlfcn.h>
+#include <assert.h>
+#include <string.h>
+#include <stdio.h>
+
+#ifdef USE_HOST_LIBC
+#define LIBBAR "libnative-bar.so"
+#define LIBBAZ "libnative-baz.so"
+#else
+#define LIBBAR "libbar.so"
+#define LIBBAZ "libbaz.so"
+#endif
+
+typedef char *strfn(void);
+
+int main() {
+	void *baz = dlopen(LIBBAZ, RTLD_LAZY | RTLD_GLOBAL);
+	assert(baz);
+
+	// At this point, baz is loaded in the global scope. When we load bar locally,
+	// there is a relocation to `foo_baz_conflict` which is defined in both
+	// foo (which is a dependency of bar), and baz. In this case baz should win
+	// since we search the global scope first.
+
+	void *bar = dlopen(LIBBAR, RTLD_LAZY | RTLD_LOCAL);
+	assert(bar);
+
+	strfn *bfn = dlsym(bar, "bar_calls_foo_baz_conflict");
+	assert(!strcmp(bfn(), "resolved to baz"));
+
+	// TODO: Test RTLD_DEEPBIND and DT_SYMBOLIC once we implement it.
+
+	dlclose(bar);
+	dlclose(baz);
+}

tests/rtdl/scope3/libbar.c

@@ -0,0 +1,8 @@
+int g = 1;
+
+int call_foo();
+
+int call_bar() {
+	return call_foo();
+}
+

tests/rtdl/scope3/libbaz.c

@@ -0,0 +1,7 @@
+int g = 2;
+
+int call_foo();
+
+int call_baz() {
+	return call_foo();
+}

tests/rtdl/scope3/libfoo.c

@@ -0,0 +1,5 @@
+int g = 0;
+
+int call_foo() {
+	return g;
+}

tests/rtdl/scope3/meson.build

@@ -0,0 +1,9 @@
+libfoo = shared_library('foo', 'libfoo.c')
+libbar = shared_library('bar', 'libbar.c', build_rpath: test_rpath, link_with: libfoo)
+libbaz = shared_library('baz', 'libbaz.c', build_rpath: test_rpath, link_with: libfoo)
+test_depends = [libfoo, libbar, libbaz]
+
+libfoo_native = shared_library('native-foo', 'libfoo.c', native: true)
+libbar_native = shared_library('native-bar', 'libbar.c', build_rpath: test_rpath, link_with: libfoo_native, native: true)
+libbaz_native = shared_library('native-baz', 'libbaz.c', build_rpath: test_rpath, link_with: libfoo_native, native: true)
+test_native_depends = [libfoo_native, libbar_native, libbaz_native]

tests/rtdl/scope3/test.c

@@ -0,0 +1,39 @@
+#include <dlfcn.h>
+#include <stdio.h>
+#include <assert.h>
+
+#ifdef USE_HOST_LIBC
+#define LIBBAR "libnative-bar.so"
+#define LIBBAZ "libnative-baz.so"
+#else
+#define LIBBAR "libbar.so"
+#define LIBBAZ "libbaz.so"
+#endif
+
+int main() {
+	// In this test, we have bar -> foo and baz -> foo (where -> means 'depends on').
+	// All three objects contain a definition of a symbol g. Bar calls into foo to retrieve
+	// what foo thinks g is, but since bar appears earlier in the scope than foo, bar's copy
+	// of g wins.
+	//
+	// Next, we load baz, which is identical to bar. When baz calls into foo to retrieve g,
+	// foo still sees bar's definition of g, so bar's copy of g wins.
+	//
+	// Swapping the load order of bar and baz should therefore change the value of g which
+	// foo sees. This behaviour is why dlmopen exists. If we ever implement that, we should
+	// write a similar test and assert that the calls return different results.
+
+	void *libbar = dlopen(LIBBAR, RTLD_LAZY | RTLD_LOCAL);
+	int (*call_bar)(void) = dlsym(libbar, "call_bar");
+	printf("call_bar: %d\n", call_bar());
+	assert(call_bar() == 1);
+
+	void *libbaz = dlopen(LIBBAZ, RTLD_LAZY | RTLD_LOCAL);
+	int (*call_baz)(void) = dlsym(libbaz, "call_baz");
+	printf("call_baz: %d\n", call_baz());
+	assert(call_baz() == 1);
+
+
+	dlclose(libbar);
+	dlclose(libbaz);
+}

tests/rtdl/scope4/libbar.c

@@ -0,0 +1,3 @@
+// Bar needs to have a relocation against foo in order to set DT_NEEDED.
+void foo(void);
+void bar() { foo(); }

tests/rtdl/scope4/libbaz.c

@@ -0,0 +1 @@
+void baz() {}

tests/rtdl/scope4/libfoo.c

@@ -0,0 +1,3 @@
+// Foo needs to have a relocation against baz in order to set DT_NEEDED.
+void baz(void);
+void foo() { baz(); }

tests/rtdl/scope4/meson.build

@@ -0,0 +1,9 @@
+libbaz = shared_library('baz', 'libbaz.c')
+libfoo = shared_library('foo', 'libfoo.c', build_rpath: test_rpath, link_with: libbaz)
+libbar = shared_library('bar', 'libbar.c', build_rpath: test_rpath, link_with: libfoo)
+test_depends = [libfoo, libbar, libbaz]
+
+libbaz_native = shared_library('native-baz', 'libbaz.c', native: true)
+libfoo_native = shared_library('native-foo', 'libfoo.c', build_rpath: test_rpath, link_with: libbaz_native, native: true)
+libbar_native = shared_library('native-bar', 'libbar.c', build_rpath: test_rpath, link_with: libfoo_native, native: true)
+test_native_depends = [libfoo_native, libbar_native, libbaz_native]

tests/rtdl/scope4/test.c

@@ -0,0 +1,36 @@
+#include <dlfcn.h>
+#include <stdio.h>
+#include <assert.h>
+
+#ifdef USE_HOST_LIBC
+#define LIBFOO "libnative-foo.so"
+#define LIBBAR "libnative-bar.so"
+#define LIBBAZ "libnative-baz.so"
+#else
+#define LIBFOO "libfoo.so"
+#define LIBBAR "libbar.so"
+#define LIBBAZ "libbaz.so"
+#endif
+
+int main() {
+	// In this test, we have foo -> baz, bar -> foo (where '->' means 'depends on').
+	// We first load foo with RTLD_LOCAL, and then load bar with RTLD_GLOBAL.
+	// This should bring foo and bar into the global scope.
+
+	void *foo = dlopen(LIBFOO, RTLD_LOCAL | RTLD_NOW);
+	assert(foo);
+	assert(dlsym(foo, "foo"));
+	assert(dlsym(foo, "baz"));
+	assert(!dlsym(RTLD_DEFAULT, "foo"));
+	assert(!dlsym(RTLD_DEFAULT, "baz"));
+
+	void *bar = dlopen(LIBBAR, RTLD_GLOBAL | RTLD_NOW);
+	assert(bar);
+	assert(dlsym(bar, "bar"));
+	assert(dlsym(RTLD_DEFAULT, "bar"));
+	assert(dlsym(RTLD_DEFAULT, "foo"));
+	assert(dlsym(RTLD_DEFAULT, "baz"));
+
+	dlclose(foo);
+	dlclose(bar);
+}