fault/vdso/restorer: add force-injection of trampolines

To check that jump trampolines to rt-vdso works.
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Dmitry Safonov <dsafonov@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

criu/include/fault-injection.h

@@ -11,6 +11,7 @@ enum faults {
 	FI_PARASITE_CONNECT,
 	FI_POST_RESTORE,
 	/* not fatal */
+	FI_VDSO_TRAMPOLINES = 127,
 	FI_CHECK_OPEN_HANDLE = 128,
 	FI_NO_MEMFD = 129,
 	FI_NO_BREAKPOINTS = 130,

criu/include/parasite-vdso.h

@@ -83,7 +83,8 @@ extern int vdso_do_park(struct vdso_symtable *sym_rt, unsigned long park_at, uns
 extern int vdso_map_compat(unsigned long map_at);
 extern int vdso_proxify(struct vdso_symtable *sym_rt,
 			unsigned long vdso_rt_parked_at,
-			VmaEntry *vmas, size_t nr_vmas, bool compat_vdso);
+			VmaEntry *vmas, size_t nr_vmas,
+			bool compat_vdso, bool force_trampolines);
 
 #else /* CONFIG_VDSO */
 #define vdso_do_park(sym_rt, park_at, park_size)		(0)

criu/pie/parasite-vdso.c

@@ -103,9 +103,9 @@ int __vdso_fill_symtable(uintptr_t mem, size_t size,
 }
 #endif
 
-int vdso_proxify(struct vdso_symtable *sym_rt,
-		 unsigned long vdso_rt_parked_at,
-		 VmaEntry *vmas, size_t nr_vmas, bool compat_vdso)
+int vdso_proxify(struct vdso_symtable *sym_rt, unsigned long vdso_rt_parked_at,
+		 VmaEntry *vmas, size_t nr_vmas,
+		 bool compat_vdso, bool force_trampolines)
 {
 	VmaEntry *vma_vdso = NULL, *vma_vvar = NULL;
 	struct vdso_symtable s = VDSO_SYMTABLE_INIT;
@@ -193,7 +193,7 @@ int vdso_proxify(struct vdso_symtable *sym_rt,
 	 * by a caller code. So drop VMA_AREA_REGULAR from it and caller would
 	 * not touch it anymore.
 	 */
-	if (remap_rt) {
+	if (remap_rt && !force_trampolines) {
 		int ret = 0;
 
 		pr_info("Runtime vdso/vvar matches dumpee, remap inplace\n");

criu/pie/restorer.c

@@ -1193,7 +1193,8 @@ long __export_restore_task(struct task_restore_args *args)
 	 * Proxify vDSO.
 	 */
 	if (vdso_proxify(&args->vdso_sym_rt, args->vdso_rt_parked_at,
-		     args->vmas, args->vmas_n, args->compatible_mode))
+		     args->vmas, args->vmas_n, args->compatible_mode,
+		     fault_injected(FI_VDSO_TRAMPOLINES)))
 		goto core_restore_end;
 #endif
 

test/jenkins/criu-fault.sh

@@ -9,6 +9,7 @@ prep
 ./test/zdtm.py run -t zdtm/static/inotify_irmap --fault 128 --keep-going --pre 2 -f uns || fail
 ./test/zdtm.py run -t zdtm/static/env00 --fault 129 -f uns || fail
 ./test/zdtm.py run -t zdtm/transition/fork --fault 130 -f h || fail
+./test/zdtm.py run -t zdtm/static/vdso01 --fault 127 || fail
 
 ./test/zdtm.py run -t zdtm/static/mntns_ghost --fault 2 --keep-going --report report || fail
 ./test/zdtm.py run -t zdtm/static/mntns_ghost --fault 4 --keep-going --report report || fail