diff --git a/sys/kern_mtx.pas b/sys/kern_mtx.pas
new file mode 100644
index 00000000..6636a368
--- /dev/null
+++ b/sys/kern_mtx.pas
@@ -0,0 +1,45 @@
+unit kern_mtx;
+
+{$mode ObjFPC}{$H+}
+{$CALLING SysV_ABI_CDecl}
+
+interface
+
+uses
+ windows,
+ ntapi;
+
+function mtx_init(m:PPointer):Integer;
+function mtx_destroy(m:PPointer):Integer;
+function mtx_lock(m:PPointer):Integer;
+function mtx_unlock(m:PPointer):Integer;
+
+implementation
+
+function mtx_init(m:PPointer):Integer;
+begin
+ Result:=NtCreateMutant(
+           PHandle(m),
+           MUTANT_ALL_ACCESS,
+           nil,
+           False);
+end;
+
+function mtx_destroy(m:PPointer):Integer;
+begin
+ Result:=NtClose(THandle(m^));
+end;
+
+function mtx_lock(m:PPointer):Integer;
+begin
+ Result:=NtWaitForSingleObject(THandle(m^),False,nil);
+end;
+
+function mtx_unlock(m:PPointer):Integer;
+begin
+ Result:=NtReleaseMutant(THandle(m^),nil);
+end;
+
+
+end.
+
diff --git a/sys/kern_sig.pas b/sys/kern_sig.pas
index ab9785df..a91f5774 100644
--- a/sys/kern_sig.pas
+++ b/sys/kern_sig.pas
@@ -76,18 +76,26 @@ Function  sys_sigsuspend(sigmask:p_sigset_t):Integer;
 
 Function  sys_sigaltstack(ss:p_stack_t;oss:p_stack_t):Integer;
 
+Function  sigonstack(sp:size_t):Integer;
 procedure sigqueue_init(list:p_sigqueue);
 procedure tdsigcleanup(td:p_kthread);
 
+procedure tdsignal(td:p_kthread;sig:Integer);
+procedure tdksignal(td:p_kthread;sig:Integer;ksi:p_ksiginfo);
+procedure sigexit(td:p_kthread;sig:Integer);
+
 procedure ast;
 
+function  ps_mtx_lock:Integer;
+function  ps_mtx_unlock:Integer;
+
 implementation
 
 uses
  ntapi,
  systm,
  _umtx,
- kern_umtx,
+ kern_mtx,
  kern_time,
  vm_machdep,
  machdep;
@@ -134,7 +142,7 @@ end;
 
 Function sigqueue_get(sq:p_sigqueue;signo:Integer;si:p_ksiginfo):Integer;
 var
- ksi:p_ksiginfo;
+ ksi,next:p_ksiginfo;
  count:Integer;
 begin
  count:=0;
@@ -152,6 +160,7 @@ begin
  ksi:=TAILQ_FIRST(@sq^.sq_list);
  While (ksi<>nil) do
  begin
+  next:=TAILQ_NEXT(ksi,@ksi^.ksi_link);
   if (ksi^.ksi_info.si_signo=signo) then
   begin
    if (count=0) then
@@ -173,7 +182,7 @@ begin
     Inc(count);
    end;
   end;
-  ksi:=TAILQ_NEXT(ksi,@ksi^.ksi_link);
+  ksi:=next;
  end;
 
  if (count<=1) then
@@ -283,20 +292,21 @@ end;
 
 procedure sigqueue_flush(sq:p_sigqueue);
 var
- ksi:p_ksiginfo;
+ ksi,next:p_ksiginfo;
 begin
  Assert((sq^.sq_flags and SQ_INIT)<>0,'sigqueue not inited');
 
  ksi:=TAILQ_FIRST(@sq^.sq_list);
  while (ksi<>nil) do
  begin
+  next:=TAILQ_NEXT(ksi,@ksi^.ksi_link);
   TAILQ_REMOVE(@sq^.sq_list,ksi,@ksi^.ksi_link);
   ksi^.ksi_sigq:=nil;
   if ksiginfo_tryfree(ksi) then
   begin
    Dec(p_pendingcnt);
   end;
-  ksi:=TAILQ_NEXT(ksi,@ksi^.ksi_link);
+  ksi:=next;
  end;
 
  SIGEMPTYSET(@sq^.sq_signals);
@@ -306,7 +316,7 @@ end;
 procedure sigqueue_move_set(src,dst:p_sigqueue;_set:p_sigset_t);
 var
  tmp:sigset_t;
- ksi:p_ksiginfo;
+ ksi,next:p_ksiginfo;
 begin
  Assert((src^.sq_flags and SQ_INIT)<>0,'sigqueue not inited');
  Assert((dst^.sq_flags and SQ_INIT)<>0,'sigqueue not inited');
@@ -314,6 +324,8 @@ begin
  ksi:=TAILQ_FIRST(@src^.sq_list);
  while (ksi<>nil) do
  begin
+  next:=TAILQ_NEXT(ksi,@ksi^.ksi_link);
+
   if SIGISMEMBER(_set,ksi^.ksi_info.si_signo) then
   begin
    TAILQ_REMOVE(@src^.sq_list,ksi,@ksi^.ksi_link);
@@ -321,7 +333,7 @@ begin
    ksi^.ksi_sigq:=dst;
   end;
 
-  ksi:=TAILQ_NEXT(ksi,@ksi^.ksi_link);
+  ksi:=next;
  end;
 
  tmp:=src^.sq_kill;
@@ -337,13 +349,15 @@ end;
 
 procedure sigqueue_delete_set(sq:p_sigqueue;_set:p_sigset_t);
 var
- ksi:p_ksiginfo;
+ ksi,next:p_ksiginfo;
 begin
  Assert((sq^.sq_flags and SQ_INIT)<>0,'sigqueue not inited');
 
  ksi:=TAILQ_FIRST(@sq^.sq_list);
  while (ksi<>nil) do
  begin
+  next:=TAILQ_NEXT(ksi,@ksi^.ksi_link);
+
   if SIGISMEMBER(_set,ksi^.ksi_info.si_signo) then
   begin
    TAILQ_REMOVE(@sq^.sq_list,ksi,@ksi^.ksi_link);
@@ -354,7 +368,7 @@ begin
    end;
   end;
 
-  ksi:=TAILQ_NEXT(ksi,@ksi^.ksi_link);
+  ksi:=next;
  end;
 
  SIGSETNAND(@sq^.sq_kill,_set);
@@ -470,14 +484,14 @@ begin
  end;
 end;
 
-function mtx_lock(m:p_umtx):Integer; inline;
+function ps_mtx_lock:Integer;
 begin
- Result:=_sys_umtx_lock(m);
+ Result:=mtx_lock(@p_sigacts.ps_mtx);
 end;
 
-function mtx_unlock(m:p_umtx):Integer; inline;
+function ps_mtx_unlock:Integer;
 begin
- Result:=_sys_umtx_unlock(m);
+ Result:=mtx_unlock(@p_sigacts.ps_mtx);
 end;
 
 Function kern_sigaction(sig:Integer;
@@ -486,108 +500,108 @@ begin
  if (not _SIG_VALID(sig)) then Exit(EINVAL);
 
  PROC_LOCK;
- mtx_lock(@p_sigacts.ps_mtx);
+ ps_mtx_lock;
 
  if (oact<>nil) then
  begin
-  oact^.sa_mask := p_sigacts.ps_catchmask[_SIG_IDX(sig)];
-  oact^.sa_flags := 0;
-  if (SIGISMEMBER(@p_sigacts.ps_sigonstack, sig)) then
-   oact^.sa_flags := oact^.sa_flags or SA_ONSTACK;
-  if (not SIGISMEMBER(@p_sigacts.ps_sigintr, sig)) then
-   oact^.sa_flags := oact^.sa_flags or SA_RESTART;
-  if (SIGISMEMBER(@p_sigacts.ps_sigreset, sig)) then
-   oact^.sa_flags := oact^.sa_flags or SA_RESETHAND;
-  if (SIGISMEMBER(@p_sigacts.ps_signodefer, sig)) then
-   oact^.sa_flags := oact^.sa_flags or SA_NODEFER;
-  if (SIGISMEMBER(@p_sigacts.ps_siginfo, sig)) then
+  oact^.sa_mask:=p_sigacts.ps_catchmask[_SIG_IDX(sig)];
+  oact^.sa_flags:=0;
+  if (SIGISMEMBER(@p_sigacts.ps_sigonstack,sig)) then
+   oact^.sa_flags:=oact^.sa_flags or SA_ONSTACK;
+  if (not SIGISMEMBER(@p_sigacts.ps_sigintr,sig)) then
+   oact^.sa_flags:=oact^.sa_flags or SA_RESTART;
+  if (SIGISMEMBER(@p_sigacts.ps_sigreset,sig)) then
+   oact^.sa_flags:=oact^.sa_flags or SA_RESETHAND;
+  if (SIGISMEMBER(@p_sigacts.ps_signodefer,sig)) then
+   oact^.sa_flags:=oact^.sa_flags or SA_NODEFER;
+  if (SIGISMEMBER(@p_sigacts.ps_siginfo,sig)) then
   begin
-   oact^.sa_flags := oact^.sa_flags or SA_SIGINFO;
-   oact^.u.sa_handler := p_sigacts.ps_sigact[_SIG_IDX(sig)];
+   oact^.sa_flags:=oact^.sa_flags or SA_SIGINFO;
+   oact^.u.sa_handler:=p_sigacts.ps_sigact[_SIG_IDX(sig)];
   end else
   begin
-   oact^.u.sa_handler := p_sigacts.ps_sigact[_SIG_IDX(sig)];
+   oact^.u.sa_handler:=p_sigacts.ps_sigact[_SIG_IDX(sig)];
   end;
-  if (sig = SIGCHLD and p_sigacts.ps_flag and PS_NOCLDSTOP) then
-   oact^.sa_flags := oact^.sa_flags or SA_NOCLDSTOP;
-  if (sig = SIGCHLD and p_sigacts.ps_flag and PS_NOCLDWAIT) then
-   oact^.sa_flags := oact^.sa_flags or SA_NOCLDWAIT;
+  if (sig=SIGCHLD and p_sigacts.ps_flag and PS_NOCLDSTOP) then
+   oact^.sa_flags:=oact^.sa_flags or SA_NOCLDSTOP;
+  if (sig=SIGCHLD and p_sigacts.ps_flag and PS_NOCLDWAIT) then
+   oact^.sa_flags:=oact^.sa_flags or SA_NOCLDWAIT;
  end;
  if (act<>nil) then
  begin
-  if ((sig = SIGKILL) or (sig = SIGSTOP)) and
-      (act^.u.code <> SIG_DFL) then
+  if ((sig=SIGKILL) or (sig=SIGSTOP)) and
+      (act^.u.code<>SIG_DFL) then
   begin
-   mtx_unlock(@p_sigacts.ps_mtx);
+   ps_mtx_unlock;
    PROC_UNLOCK;
    Result:=EINVAL;
   end;
 
-  p_sigacts.ps_catchmask[_SIG_IDX(sig)] := act^.sa_mask;
+  p_sigacts.ps_catchmask[_SIG_IDX(sig)]:=act^.sa_mask;
   SIG_CANTMASK(@p_sigacts.ps_catchmask[_SIG_IDX(sig)]);
   if ((act^.sa_flags and SA_SIGINFO)<>0) then
   begin
-   p_sigacts.ps_sigact[_SIG_IDX(sig)] := act^.u.sa_handler;
-   SIGADDSET(@p_sigacts.ps_siginfo, sig);
+   p_sigacts.ps_sigact[_SIG_IDX(sig)]:=act^.u.sa_handler;
+   SIGADDSET(@p_sigacts.ps_siginfo,sig);
   end else
   begin
-   p_sigacts.ps_sigact[_SIG_IDX(sig)] := act^.u.sa_handler;
-   SIGDELSET(@p_sigacts.ps_siginfo, sig);
+   p_sigacts.ps_sigact[_SIG_IDX(sig)]:=act^.u.sa_handler;
+   SIGDELSET(@p_sigacts.ps_siginfo,sig);
   end;
   if ((act^.sa_flags and SA_RESTART)=0) then
-   SIGADDSET(@p_sigacts.ps_sigintr, sig)
+   SIGADDSET(@p_sigacts.ps_sigintr,sig)
   else
-   SIGDELSET(@p_sigacts.ps_sigintr, sig);
+   SIGDELSET(@p_sigacts.ps_sigintr,sig);
   if ((act^.sa_flags and SA_ONSTACK)<>0) then
-   SIGADDSET(@p_sigacts.ps_sigonstack, sig)
+   SIGADDSET(@p_sigacts.ps_sigonstack,sig)
   else
-   SIGDELSET(@p_sigacts.ps_sigonstack, sig);
+   SIGDELSET(@p_sigacts.ps_sigonstack,sig);
   if ((act^.sa_flags and SA_RESETHAND)<>0) then
-   SIGADDSET(@p_sigacts.ps_sigreset, sig)
+   SIGADDSET(@p_sigacts.ps_sigreset,sig)
   else
-   SIGDELSET(@p_sigacts.ps_sigreset, sig);
+   SIGDELSET(@p_sigacts.ps_sigreset,sig);
   if ((act^.sa_flags and SA_NODEFER)<>0) then
-   SIGADDSET(@p_sigacts.ps_signodefer, sig)
+   SIGADDSET(@p_sigacts.ps_signodefer,sig)
   else
-   SIGDELSET(@p_sigacts.ps_signodefer, sig);
-  if (sig = SIGCHLD) then
+   SIGDELSET(@p_sigacts.ps_signodefer,sig);
+  if (sig=SIGCHLD) then
   begin
    if ((act^.sa_flags and SA_NOCLDSTOP)<>0) then
-    p_sigacts.ps_flag := p_sigacts.ps_flag or PS_NOCLDSTOP
+    p_sigacts.ps_flag:=p_sigacts.ps_flag or PS_NOCLDSTOP
    else
-    p_sigacts.ps_flag := p_sigacts.ps_flag and (not PS_NOCLDSTOP);
+    p_sigacts.ps_flag:=p_sigacts.ps_flag and (not PS_NOCLDSTOP);
    if ((act^.sa_flags and SA_NOCLDWAIT)<>0) then
    begin
-    p_sigacts.ps_flag := p_sigacts.ps_flag or PS_NOCLDWAIT;
+    p_sigacts.ps_flag:=p_sigacts.ps_flag or PS_NOCLDWAIT;
    end else
-    p_sigacts.ps_flag := p_sigacts.ps_flag and (not PS_NOCLDWAIT);
-   if (p_sigacts.ps_sigact[_SIG_IDX(SIGCHLD)] = sig_t(SIG_IGN)) then
-    p_sigacts.ps_flag := p_sigacts.ps_flag or PS_CLDSIGIGN
+    p_sigacts.ps_flag:=p_sigacts.ps_flag and (not PS_NOCLDWAIT);
+   if (p_sigacts.ps_sigact[_SIG_IDX(SIGCHLD)]=sig_t(SIG_IGN)) then
+    p_sigacts.ps_flag:=p_sigacts.ps_flag or PS_CLDSIGIGN
    else
-    p_sigacts.ps_flag := p_sigacts.ps_flag and (not PS_CLDSIGIGN);
+    p_sigacts.ps_flag:=p_sigacts.ps_flag and (not PS_CLDSIGIGN);
   end;
 
-  if (p_sigacts.ps_sigact[_SIG_IDX(sig)] = sig_t(SIG_IGN)) or
+  if (p_sigacts.ps_sigact[_SIG_IDX(sig)]=sig_t(SIG_IGN)) or
       (((sigprop(sig) and SA_IGNORE)<>0) and
-       (p_sigacts.ps_sigact[_SIG_IDX(sig)] = sig_t(SIG_DFL))) then
+       (p_sigacts.ps_sigact[_SIG_IDX(sig)]=sig_t(SIG_DFL))) then
   begin
    sigqueue_delete_proc(sig);
-   if (sig <> SIGCONT) then
+   if (sig<>SIGCONT) then
    begin
-    SIGADDSET(@p_sigacts.ps_sigignore, sig);
+    SIGADDSET(@p_sigacts.ps_sigignore,sig);
    end;
-   SIGDELSET(@p_sigacts.ps_sigcatch, sig);
+   SIGDELSET(@p_sigacts.ps_sigcatch,sig);
   end else
   begin
-   SIGDELSET(@p_sigacts.ps_sigignore, sig);
-   if (p_sigacts.ps_sigact[_SIG_IDX(sig)] = sig_t(SIG_DFL)) then
-    SIGDELSET(@p_sigacts.ps_sigcatch, sig)
+   SIGDELSET(@p_sigacts.ps_sigignore,sig);
+   if (p_sigacts.ps_sigact[_SIG_IDX(sig)]=sig_t(SIG_DFL)) then
+    SIGDELSET(@p_sigacts.ps_sigcatch,sig)
    else
-    SIGADDSET(@p_sigacts.ps_sigcatch, sig);
+    SIGADDSET(@p_sigacts.ps_sigcatch,sig);
   end;
  end;
 
- mtx_unlock(@p_sigacts.ps_mtx);
+ ps_mtx_unlock;
  PROC_UNLOCK;
  Result:=0;
 end;
@@ -623,17 +637,17 @@ procedure siginit;
 var
  i:Integer;
 begin
- PROC_LOCK;
+ mtx_init(@p_sigacts.ps_mtx);
 
  For i:=1 to NSIG do
  begin
-  if ((sigprop(i) and SA_IGNORE)<>0) and (i <> SIGCONT) then
+  if ((sigprop(i) and SA_IGNORE)<>0) and (i<>SIGCONT) then
   begin
-   SIGADDSET(@p_sigacts.ps_sigignore, i);
+   SIGADDSET(@p_sigacts.ps_sigignore,i);
   end;
  end;
 
- PROC_UNLOCK;
+ sigqueue_init(@g_p_sigqueue);
 end;
 
 procedure reschedule_signals(block:sigset_t;flags:Integer); forward;
@@ -661,16 +675,16 @@ begin
   oset^:=td^.td_sigmask;
  end;
 
- if (_set <> nil) then
+ if (_set<>nil) then
  begin
 
   Case how of
   SIG_BLOCK:
    begin
     SIG_CANTMASK(_set);
-    oset1 := td^.td_sigmask;
+    oset1:=td^.td_sigmask;
     SIGSETOR(@td^.td_sigmask, _set);
-    new_block := td^.td_sigmask;
+    new_block:=td^.td_sigmask;
     SIGSETNAND(@new_block, @oset1);
    end;
    SIG_UNBLOCK:
@@ -682,18 +696,18 @@ begin
    SIG_SETMASK:
    begin
     SIG_CANTMASK(_set);
-    oset1 := td^.td_sigmask;
+    oset1:=td^.td_sigmask;
     if ((flags and SIGPROCMASK_OLD)<>0) then
      SIGSETLO(@td^.td_sigmask, _set)
     else
-     td^.td_sigmask := _set^;
-    new_block := td^.td_sigmask;
+     td^.td_sigmask:=_set^;
+    new_block:=td^.td_sigmask;
     SIGSETNAND(@new_block, @oset1);
     signotify(td);
    end;
    else
     begin
-     Result := EINVAL;
+     Result:=EINVAL;
      goto _out;
     end;
    end;
@@ -758,8 +772,6 @@ begin
  Result:=copyout(@pending,oset,sizeof(sigset_t));
 end;
 
-procedure sigexit(td:p_kthread;sig:Integer); forward;
-
 Function kern_sigtimedwait(td:p_kthread;
                            waitset:sigset_t;
                            ksi:p_ksiginfo;
@@ -795,9 +807,9 @@ begin
  SIGSETNAND(@td^.td_sigmask,@waitset);
 
  repeat
-  mtx_lock(@p_sigacts.ps_mtx);
+  ps_mtx_lock;
   sig:=cursig(td,SIG_STOP_ALLOWED);
-  mtx_unlock(@p_sigacts.ps_mtx);
+  ps_mtx_unlock;
 
   if (sig<>0) and SIGISMEMBER(@waitset,sig) then
   begin
@@ -974,7 +986,7 @@ begin
 
   //thread_suspend_check(0);
 
-  mtx_lock(@p_sigacts.ps_mtx);
+  ps_mtx_lock;
 
   repeat
    sig:=cursig(td,SIG_STOP_ALLOWED);
@@ -982,7 +994,7 @@ begin
    has_sig:=has_sig+postsig(sig);
   until false;
 
-  mtx_unlock(@p_sigacts.ps_mtx);
+  ps_mtx_unlock;
  end;
 
  PROC_UNLOCK;
@@ -1011,7 +1023,7 @@ var
 begin
  oonstack:=sigonstack(cpu_getstack(td));
 
- if (oss <> nil) then
+ if (oss<>nil) then
  begin
   oss^:=td^.td_sigstk;
 
@@ -1121,14 +1133,14 @@ begin
  Assert(_SIG_VALID(sig),'invalid signal');
 
  PROC_LOCK;
- mtx_lock(@p_sigacts.ps_mtx);
+ ps_mtx_lock;
 
  if SIGISMEMBER(@p_sigacts.ps_sigcatch,sig) and
     (not SIGISMEMBER(@td^.td_sigmask,sig)) then
  begin
   sendsig(p_sigacts.ps_sigact[_SIG_IDX(sig)],ksi,@td^.td_sigmask);
   postsig_done(sig,td);
-  mtx_unlock(@p_sigacts.ps_mtx);
+  ps_mtx_unlock;
  end else
  begin
   //ignoring?
@@ -1143,7 +1155,7 @@ begin
    p_sigacts.ps_sigact[_SIG_IDX(sig)]:=sig_t(SIG_DFL);
   end;
 
-  mtx_unlock(@p_sigacts.ps_mtx);
+  ps_mtx_unlock;
 
   tdsendsignal(td,sig,ksi);
  end;
@@ -1239,11 +1251,11 @@ begin
   sigqueue:=@td^.td_sigqueue;
  end;
 
- mtx_lock(@p_sigacts.ps_mtx);
+ ps_mtx_lock;
 
  if (SIGISMEMBER(@p_sigacts.ps_sigignore,sig)) then
  begin
-  mtx_unlock(@p_sigacts.ps_mtx);
+  ps_mtx_unlock;
 
   if (ksi<>nil) then
   if (ksi^.ksi_flags and KSI_INS)<>0 then
@@ -1266,7 +1278,7 @@ begin
  else
   intrval:=ERESTART;
 
- mtx_unlock(@p_sigacts.ps_mtx);
+ ps_mtx_unlock;
 
  if ((prop and SA_CONT)<>0) then
  begin
@@ -1286,6 +1298,21 @@ begin
  tdsigwakeup(td,sig,action,intrval);
 end;
 
+procedure tdsignal(td:p_kthread;sig:Integer);
+var
+ ksi:ksiginfo_t;
+begin
+ ksiginfo_init(@ksi);
+ ksi.ksi_info.si_signo:=sig;
+ ksi.ksi_info.si_code :=SI_KERNEL;
+ tdsendsignal(td,sig,@ksi);
+end;
+
+procedure tdksignal(td:p_kthread;sig:Integer;ksi:p_ksiginfo);
+begin
+ tdsendsignal(td,sig,ksi);
+end;
+
 procedure forward_signal(td:p_kthread);
 begin
  //TODO
@@ -1371,7 +1398,7 @@ begin
 
   if ((flags and SIGPROCMASK_PS_LOCKED)=0) then
   begin
-   mtx_lock(@p_sigacts.ps_mtx);
+   ps_mtx_lock;
   end;
 
   if SIGISMEMBER(@p_sigacts.ps_sigcatch,sig) then
@@ -1387,7 +1414,7 @@ begin
 
   if ((flags and SIGPROCMASK_PS_LOCKED)=0) then
   begin
-   mtx_unlock(@p_sigacts.ps_mtx);
+   ps_mtx_unlock;
   end;
  until false;
 end;
@@ -1462,12 +1489,12 @@ begin
     begin
      if ((prop and SA_STOP)<>0) then
      begin
-      mtx_unlock(@p_sigacts.ps_mtx);
+      ps_mtx_unlock;
       PROC_LOCK;
       //sig_suspend_threads(td, p, 0);
       //thread_suspend_switch(td);
       PROC_UNLOCK;
-      mtx_lock(@p_sigacts.ps_mtx);
+      ps_mtx_lock;
      end else
      if ((prop and SA_IGNORE)<>0) then
      begin
@@ -1511,19 +1538,19 @@ begin
 
  ksi.ksi_info.si_signo:=sig;
 
- //if (ksi.ksi_code = SI_TIMER)
+ //if (ksi.ksi_code=SI_TIMER)
  // itimer_accept(p, ksi.ksi_timerid, &ksi);
 
  action:=p_sigacts.ps_sigact[_SIG_IDX(sig)];
 
  if (action=sig_t(SIG_DFL)) then
  begin
-  mtx_unlock(@p_sigacts.ps_mtx);
+  ps_mtx_unlock;
   sigexit(td,sig);
   // NOTREACHED
  end else
  begin
-  Assert((action<>sig_t(SIG_IGN)) and (not SIGISMEMBER(@td^.td_sigmask, sig)),'postsig action');
+  Assert((action<>sig_t(SIG_IGN)) and (not SIGISMEMBER(@td^.td_sigmask,sig)),'postsig action');
 
   if ((td^.td_pflags and TDP_OLDMASK)<>0) then
   begin
@@ -1595,7 +1622,7 @@ begin
     (not SIGISEMPTY(@g_p_sigqueue.sq_list)) then
  begin
   PROC_LOCK;
-  mtx_lock(@p_sigacts.ps_mtx);
+  ps_mtx_lock;
 
   repeat
    sig:=cursig(td,SIG_STOP_ALLOWED);
@@ -1603,7 +1630,7 @@ begin
    postsig(sig);
   until false;
 
-  mtx_unlock(@p_sigacts.ps_mtx);
+  ps_mtx_unlock;
   PROC_UNLOCK;
  end;
 
diff --git a/sys/kern_thread.pas b/sys/kern_thread.pas
index 0c6aebb9..80fa37cf 100644
--- a/sys/kern_thread.pas
+++ b/sys/kern_thread.pas
@@ -130,7 +130,6 @@ type
   td_user_pri     :Word;
   td_name         :array[0..31] of AnsiChar;
   //
-  td_fsbase       :Pointer;
   td_cpuset       :Ptruint;
   td_sigmask      :sigset_t;
   td_oldsigmask   :sigset_t;
@@ -179,6 +178,7 @@ procedure thread_free(td:p_kthread);
 function  sys_thr_new(_param:p_thr_param;_size:Integer):Integer;
 function  sys_thr_self(id:PQWORD):Integer;
 procedure sys_thr_exit(state:PQWORD);
+function  sys_thr_kill(id:QWORD;sig:Integer):Integer;
 
 procedure thread_inc_ref(td:p_kthread);
 procedure thread_dec_ref(td:p_kthread);
@@ -190,7 +190,7 @@ procedure FOREACH_THREAD_IN_PROC(cb,userdata:Pointer);
 function  curkthread:p_kthread;
 procedure set_curkthread(td:p_kthread);
 
-function  SIGPENDING(td:p_kthread):Boolean; inline;
+function  SIGPENDING(td:p_kthread):Boolean;
 function  TD_IS_RUNNING(td:p_kthread):Boolean; inline;
 
 procedure PROC_LOCK;
@@ -223,6 +223,7 @@ uses
  systm,
  vm_machdep,
  kern_rwlock,
+ kern_mtx,
  kern_umtx,
  kern_sig;
 
@@ -247,7 +248,7 @@ asm
  movqq td,%gs:(0x700)
 end;
 
-function SIGPENDING(td:p_kthread):Boolean; inline;
+function SIGPENDING(td:p_kthread):Boolean;
 begin
  Result:=SIGNOTEMPTY(@td^.td_sigqueue.sq_signals) and
          sigsetmasked(@td^.td_sigqueue.sq_signals,@td^.td_sigmask);
@@ -260,16 +261,17 @@ end;
 
 procedure PROC_LOCK;
 begin
- rw_wlock(p_mtx);
+ mtx_lock(@p_mtx);
 end;
 
 procedure PROC_UNLOCK;
 begin
- rw_wunlock(p_mtx);
+ mtx_lock(@p_mtx);
 end;
 
 procedure threadinit; inline;
 begin
+ mtx_init(@p_mtx);
  FillChar(tidhashtbl,SizeOf(tidhashtbl),0);
 end;
 
@@ -740,6 +742,70 @@ begin
  // NOTREACHED
 end;
 
+type
+ p_t_stk=^_t_stk;
+ _t_stk=record
+   error:Integer;
+   sig:Integer;
+   td:p_kthread;
+   ksi:ksiginfo_t;
+ end;
+
+procedure _for_stk(td:p_kthread;data:p_t_stk); register; //Tfree_data_cb
+begin
+ if (td<>data^.td) then
+ begin
+  data^.error:=0;
+  if (data^.sig=0) then Exit;
+  tdksignal(td,data^.sig,@data^.ksi);
+ end;
+end;
+
+function sys_thr_kill(id:QWORD;sig:Integer):Integer;
+var
+ data:_t_stk;
+begin
+ data.td:=curkthread;
+
+ ksiginfo_init(@data.ksi);
+ data.ksi.ksi_info.si_signo:=sig;
+ data.ksi.ksi_info.si_code :=SI_LWP;
+
+ if (int64(id)=-1) then
+ begin
+  if (sig<>0) and (not _SIG_VALID(sig)) then
+  begin
+   Result:=EINVAL;
+  end else
+  begin
+   data.error:=ESRCH;
+   data.sig:=0;
+   PROC_LOCK;
+   FOREACH_THREAD_IN_PROC(@_for_stk,@data);
+   PROC_UNLOCK;
+   Result:=data.error;
+  end;
+ end else
+ begin
+  Result:=0;
+
+  data.td:=tdfind(DWORD(id));
+  if (data.td=nil) then Exit(ESRCH);
+
+  if (sig=0) then
+  begin
+   //
+  end else
+  if (not _SIG_VALID(sig)) then
+   Result:=EINVAL
+  else
+   tdksignal(data.td,sig,@data.ksi);
+
+  thread_dec_ref(data.td);
+
+  PROC_UNLOCK;
+ end;
+end;
 
 
 function rtp_to_pri(rtp:p_rtprio;td:p_kthread):Integer;
diff --git a/sys/machdep.pas b/sys/machdep.pas
index ae334930..2399490b 100644
--- a/sys/machdep.pas
+++ b/sys/machdep.pas
@@ -1,23 +1,160 @@
 unit machdep;
 
 {$mode ObjFPC}{$H+}
+{$CALLING SysV_ABI_CDecl}
 
 interface
 
 uses
  ntapi,
  signal,
- signalvar;
+ signalvar,
+ ucontext,
+ kern_thread;
 
 procedure sendsig(catcher:sig_t;ksi:p_ksiginfo;mask:p_sigset_t);
+function  sys_sigreturn(sigcntxp:p_ucontext_t):Integer;
 
 implementation
 
+uses
+ systm,
+ md_psl,
+ kern_sig,
+ trap;
+
 procedure sendsig(catcher:sig_t;ksi:p_ksiginfo;mask:p_sigset_t);
+var
+ td:p_kthread;
+ sf:sigframe;
+ sfp:p_sigframe;
+ regs:p_trapframe;
+ sp:QWORD;
+ sig,oonstack:Integer;
 begin
- //TODO
+ //char *xfpusave;
+ //size_t xfpusave_len;
+
+ td:=curkthread;
+
+ sig:=ksi^.ksi_info.si_signo;
+
+ //psp:=p_sigacts
+
+ regs:=td^.td_frame;
+ oonstack:=sigonstack(regs^.tf_rsp);
+
+ //if (cpu_max_ext_state_size > sizeof(struct savefpu) && use_xsave) {
+ // xfpusave_len = cpu_max_ext_state_size - sizeof(struct savefpu);
+ // xfpusave = __builtin_alloca(xfpusave_len);
+ //} else {
+ // xfpusave_len = 0;
+ // xfpusave = NULL;
+ //}
+
+ // Save user context.
+ sf:=Default(sigframe);
+
+ sf.sf_uc.uc_sigmask:=mask^;
+ sf.sf_uc.uc_stack  :=td^.td_sigstk;
+
+ if ((td^.td_pflags and TDP_ALTSTACK)<>0) then
+ begin
+  if (oonstack<>0) then
+  begin
+   sf.sf_uc.uc_stack.ss_flags:=SS_ONSTACK;
+  end else
+  begin
+   sf.sf_uc.uc_stack.ss_flags:=0;
+  end;
+ end else
+ begin
+  sf.sf_uc.uc_stack.ss_flags:=SS_DISABLE;
+ end;
+
+ sf.sf_uc.uc_mcontext.mc_onstack:=oonstack;
+
+ Move(regs^,sf.sf_uc.uc_mcontext.mc_rdi,SizeOf(trapframe));
+
+ sf.sf_uc.uc_mcontext.mc_len:=sizeof(mcontext_t);
+
+ //get_fpcontext(td, &sf.sf_uc.uc_mcontext, xfpusave, xfpusave_len);
+ //fpstate_drop(td);
+
+ //sf.sf_uc.uc_mcontext.mc_fsbase = pcb->pcb_fsbase;
+ //sf.sf_uc.uc_mcontext.mc_gsbase = pcb->pcb_gsbase;
+
+ if ((td^.td_pflags and TDP_ALTSTACK)<>0) and
+    (oonstack=0) and
+    SIGISMEMBER(@p_sigacts.ps_sigonstack,sig) then
+ begin
+  sp:=QWORD(td^.td_sigstk.ss_sp)+td^.td_sigstk.ss_size;
+ end else
+ begin
+  sp:=regs^.tf_rsp-128;
+ end;
+
+ //if (xfpusave != NULL) {
+ // sp -= xfpusave_len;
+ // sp = (char *)((unsigned long)sp & ~0x3Ful);
+ // sf.sf_uc.uc_mcontext.mc_xfpustate = (register_t)sp;
+ //}
+
+ sp:=sp-sizeof(sigframe);
+
+ sfp:=p_sigframe(sp and (not $F));
+
+ regs^.tf_rdi:=sig;
+ regs^.tf_rdx:=QWORD(@sfp^.sf_uc);
+
+ sf.sf_si:=Default(siginfo_t);
+
+ if (SIGISMEMBER(@p_sigacts.ps_siginfo,sig)) then
+ begin
+  regs^.tf_rsi:=QWORD(@sfp^.sf_si);
+  sf.sf_ahu:=Pointer(catcher);
+
+  sf.sf_si:=ksi^.ksi_info;
+  sf.sf_si.si_signo:=sig;
+
+  regs^.tf_rcx:=QWORD(ksi^.ksi_info.si_addr);
+ end else
+ begin
+  regs^.tf_rsi:=ksi^.ksi_info.si_code;
+  regs^.tf_rcx:=QWORD(ksi^.ksi_info.si_addr);
+  sf.sf_ahu:=Pointer(catcher);
+ end;
+
+ ps_mtx_unlock;
+ PROC_UNLOCK;
+
+ if (copyout(@sf,sfp,sizeof(sigframe))<>0) then
+ begin
+  PROC_LOCK;
+  sigexit(td,SIGILL);
+ end;
+
+ //if  (xfpusave != NULL && copyout(xfpusave,
+ //    (void *)sf.sf_uc.uc_mcontext.mc_xfpustate, xfpusave_len)
+ //    != 0)) {
+ // PROC_LOCK(p);
+ // sigexit(td, SIGILL);
+ //}
+
+ regs^.tf_rsp:=QWORD(sfp);
+ regs^.tf_rip:=QWORD(@sigcode);
+ regs^.tf_rflags:=regs^.tf_rflags and (not (PSL_T or PSL_D));
+
+ set_pcb_flags(td,PCB_FULL_IRET);
+ PROC_LOCK;
+ ps_mtx_lock;
 end;
 
+function sys_sigreturn(sigcntxp:p_ucontext_t):Integer;
+begin
+ //TODO
+ writeln;
+end;
 
 
 end.
diff --git a/sys/test/project1.lpi b/sys/test/project1.lpi
index bb925556..68450ac9 100644
--- a/sys/test/project1.lpi
+++ b/sys/test/project1.lpi
@@ -97,6 +97,10 @@
         <Filename Value="..\thr.pas"/>
         <IsPartOfProject Value="True"/>
       </Unit>
+      <Unit>
+        <Filename Value="..\kern_mtx.pas"/>
+        <IsPartOfProject Value="True"/>
+      </Unit>
     </Units>
   </ProjectOptions>
   <CompilerOptions>
diff --git a/sys/test/project1.lpr b/sys/test/project1.lpr
index bc5d6cf9..0a953ba4 100644
--- a/sys/test/project1.lpr
+++ b/sys/test/project1.lpr
@@ -16,7 +16,8 @@ uses
  kern_rwlock,
  thr_private,
  kern_sig,
- trap, md_psl,
+ trap,
+ md_psl,
  sysutils,
  vulkan,
  vDevice;
@@ -142,13 +143,27 @@ asm
  mov %gs:(0x708),%rax
 end;
 
+procedure __ex_handler(sig,code:Integer;ctx:p_ucontext_t); SysV_ABI_CDecl;
+begin
+ Writeln('__ex_handler:',sig,' ',code);
+end;
+
 procedure test_thread; sysv_abi_default;
 var
  rax:qword;
+ act:sigaction_t;
 begin
 
  //SetTlsBase(Pointer(qword(1)));
 
+ act:=Default(sigaction_t);
+ act.u.sa_handler:=sa_handler(@__ex_handler);
+ act.sa_flags:=SA_RESTART;
+
+ sys_sigaction(SIGUSR1,@act,nil,0);
+
+ sys_thr_kill(curkthread^.td_tid,SIGUSR1);
+
  sig_lock;
  sig_lock;
   sleep(1);
diff --git a/sys/thr.pas b/sys/thr.pas
index ecf43608..4f4fc9a1 100644
--- a/sys/thr.pas
+++ b/sys/thr.pas
@@ -1,6 +1,7 @@
 unit thr;
 
 {$mode ObjFPC}{$H+}
+{$CALLING SysV_ABI_CDecl}
 
 interface
 
diff --git a/sys/trap.pas b/sys/trap.pas
index ae2e09d9..b8643350 100644
--- a/sys/trap.pas
+++ b/sys/trap.pas
@@ -97,10 +97,12 @@ procedure _sig_unlock;
 procedure sig_unlock;
 
 procedure fast_syscall;
+procedure sigcode;
 
 implementation
 
 uses
+ machdep,
  vm_machdep,
  kern_sig;
 
@@ -149,7 +151,7 @@ asm
  popq  %rbp
 end;
 
-procedure set_pcb_flags(td:p_kthread;f:Integer); inline;
+procedure set_pcb_flags(td:p_kthread;f:Integer);
 begin
  td^.pcb_flags:=f;
 end;
@@ -352,7 +354,15 @@ asm
  //restore rip
 end;
 
-
+procedure sigcode; assembler; nostackframe;
+asm
+ call  sigframe.sf_ahu(%rsp)
+ lea   sigframe.sf_uc(%rsp),%rdi
+ pushq $0
+ movqq sys_sigreturn,%rax
+ call  fast_syscall
+ hlt
+end;
 
 
 end.
diff --git a/sys/vm_machdep.pas b/sys/vm_machdep.pas
index afc2bd9f..b13343d3 100644
--- a/sys/vm_machdep.pas
+++ b/sys/vm_machdep.pas
@@ -1,6 +1,7 @@
 unit vm_machdep;
 
 {$mode ObjFPC}{$H+}
+{$CALLING SysV_ABI_CDecl}
 
 interface