compel: Introduce compel_thread_sigmask

The plan is to rectify the thread infection API and hide
thread_ctx from uapi eventually, so here's the symmetrical
to compel_task_sigmask() call for threads.
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

compel/include/uapi/infect.h

@@ -92,6 +92,7 @@ extern int compel_unmap(struct parasite_ctl *ctl, unsigned long addr);
 extern int compel_mode_native(struct parasite_ctl *ctl);
 
 extern k_rtsigset_t *compel_task_sigmask(struct parasite_ctl *ctl);
+extern k_rtsigset_t *compel_thread_sigmask(struct thread_ctx *tctx);
 
 struct rt_sigframe;
 

compel/src/lib/infect.c

@@ -1255,9 +1255,14 @@ int compel_mode_native(struct parasite_ctl *ctl)
 	return user_regs_native(&ctl->orig.regs);
 }
 
+k_rtsigset_t *compel_thread_sigmask(struct thread_ctx *tctx)
+{
+	return &tctx->sigmask;
+}
+
 k_rtsigset_t *compel_task_sigmask(struct parasite_ctl *ctl)
 {
-	return &ctl->orig.sigmask;
+	return compel_thread_sigmask(&ctl->orig);
 }
 
 struct infect_ctx *compel_infect_ctx(struct parasite_ctl *ctl)

criu/parasite-syscall.c

@@ -201,7 +201,7 @@ int parasite_dump_thread_seized(struct parasite_ctl *ctl, int id,
 		return -1;
 
 	tc->has_blk_sigset = true;
-	memcpy(&tc->blk_sigset, &octx.sigmask, sizeof(k_rtsigset_t));
+	memcpy(&tc->blk_sigset, compel_thread_sigmask(&octx), sizeof(k_rtsigset_t));
 
 	ret = compel_run_in_thread(pid, PARASITE_CMD_DUMP_THREAD, ctl, &octx);
 	if (ret) {