Fixing commit c220f6da

Dmitry:
    Thanks for the patch, it looks like it was part of commit 1c249d08870b
    ("x86: add 32-bit sigframe for rt_sigreturn") from criu-dev.
    When I've prepared the patches set, I've tested patches separately from
    the set on x86, but hadn't possibility to test them separately on ppc.
    And for x86 it didn't matter when to call restore_gpregs() before compat
    patches, so I didn't catch that it does matter for ppc.
Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Reviewed-by: Dmitry Safonov <dsafonov@virtuozzo.com>
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>

criu/sigframe.c

@@ -27,6 +27,9 @@ int construct_sigframe(struct rt_sigframe *sigframe,
 {
 	k_rtsigset_t *blk_sigset = RT_SIGFRAME_UC_SIGMASK(sigframe);
 
+	if (restore_gpregs(sigframe, CORE_THREAD_ARCH_INFO(core)->gpregs))
+		return -1;
+
 	if (core->tc)
 		memcpy(blk_sigset, &core->tc->blk_sigset, sizeof(k_rtsigset_t));
 	else if (core->thread_core->has_blk_sigset) {
@@ -42,9 +45,6 @@ int construct_sigframe(struct rt_sigframe *sigframe,
 		if (sigreturn_prep_fpu_frame(sigframe, rsigframe))
 			return -1;
 
-	if (restore_gpregs(sigframe, CORE_THREAD_ARCH_INFO(core)->gpregs))
-		return -1;
-
 	setup_sas(sigframe, core->thread_core->sas);
 
 	return 0;