
/*--------------------------------------------------------------------*/
/*--- Create/destroy signal delivery frames.                       ---*/
/*---                                  sigframe-mips64-linux.c     ---*/
/*--------------------------------------------------------------------*/

/*
   This file is part of Valgrind, a dynamic binary instrumentation
   framework.

   Copyright (C) 2010-2013 RT-RK 
      mips-valgrind@rt-rk.com 

   This program is free software; you can redistribute it and/or
   modify it under the terms of the GNU General Public License as
   published by the Free Software Foundation; either version 2 of the
   License, or (at your option) any later version.

   This program is distributed in the hope that it will be useful, but
   WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307, USA.

   The GNU General Public License is contained in the file COPYING.
*/

#if defined(VGP_mips64_linux)

#include "pub_core_basics.h"
#include "pub_core_vki.h"
#include "pub_core_vkiscnums.h"
#include "pub_core_libcsetjmp.h"  /* to keep _threadstate.h happy */
#include "pub_core_threadstate.h"
#include "pub_core_aspacemgr.h"
#include "pub_core_libcbase.h"
#include "pub_core_libcassert.h"
#include "pub_core_libcprint.h"
#include "pub_core_machine.h"
#include "pub_core_options.h"
#include "pub_core_sigframe.h"
#include "pub_core_signals.h"
#include "pub_core_tooliface.h"
#include "pub_core_trampoline.h"
#include "pub_core_transtab.h"  /* VG_(discard_translations) */

struct vg_sig_private {
   UInt magicPI;
   UInt sigNo_private;
   VexGuestMIPS64State vex_shadow1;
   VexGuestMIPS64State vex_shadow2;
};

struct sigframe {
   UInt sf_ass[4];  /* argument save space for o32 */
   UInt sf_pad[2];  /* Was: signal trampoline */
   struct vki_sigcontext sf_sc;
   vki_sigset_t sf_mask;
   struct vg_sig_private priv;
};

struct rt_sigframe {
   UInt rs_ass[4];  /* argument save space for o32 */
   UInt rs_pad[2];  /* Was: signal trampoline */
   vki_siginfo_t rs_info;
   struct vki_ucontext rs_uc;
   struct vg_sig_private priv;
};

/* Extend the stack segment downwards if needed so as to ensure the new signal
   frames are mapped to something. Return a Bool indicating whether or not the
   operation was successful.
*/
static Bool extend ( ThreadState *tst, Addr addr, SizeT size )
{
   ThreadId tid = tst->tid;
   NSegment const* stackseg = NULL;

   if (VG_(extend_stack)(addr, tst->client_stack_szB)) {
      stackseg = VG_(am_find_nsegment)(addr);
   }

   if (stackseg == NULL || !stackseg->hasR || !stackseg->hasW) {
      VG_(message)(Vg_UserMsg,
         "Can't extend stack to %#lx during signal delivery for thread %d:\n",
         addr, tid);
      if (stackseg == NULL)
         VG_(message)(Vg_UserMsg, " no stack segment\n");
      else
         VG_(message)(Vg_UserMsg, " too small or bad protection modes\n");

      /* set SIGSEGV to default handler */
      VG_(set_default_handler)(VKI_SIGSEGV);
      VG_(synth_fault_mapping)(tid, addr);

      /* The whole process should be about to die, since the default
         action of SIGSEGV to kill the whole process. */
      return False;
   }

   /* For tracking memory events, indicate the entire frame has been
      allocated. */
   VG_TRACK(new_mem_stack_signal, addr - VG_STACK_REDZONE_SZB,
            size + VG_STACK_REDZONE_SZB, tid);

   return True;
}

static void setup_sigcontext ( ThreadState* tst, struct vki_sigcontext **sc1,
                               const vki_siginfo_t *si)
{
   struct vki_sigcontext *sc = *sc1;

   VG_TRACK(pre_mem_write, Vg_CoreSignal, tst->tid, "signal frame mcontext",
            (Addr)sc, sizeof(unsigned long long)*34);
   sc->sc_regs[1] = tst->arch.vex.guest_r1;
   sc->sc_regs[2] = tst->arch.vex.guest_r2;
   sc->sc_regs[3] = tst->arch.vex.guest_r3;
   sc->sc_regs[4] = tst->arch.vex.guest_r4;
   sc->sc_regs[5] = tst->arch.vex.guest_r5;
   sc->sc_regs[6] = tst->arch.vex.guest_r6;
   sc->sc_regs[7] = tst->arch.vex.guest_r7;
   sc->sc_regs[8] = tst->arch.vex.guest_r8;
   sc->sc_regs[9] = tst->arch.vex.guest_r9;
   sc->sc_regs[10] = tst->arch.vex.guest_r10;
   sc->sc_regs[11] = tst->arch.vex.guest_r11;
   sc->sc_regs[12] = tst->arch.vex.guest_r12;
   sc->sc_regs[13] = tst->arch.vex.guest_r13;
   sc->sc_regs[14] = tst->arch.vex.guest_r14;
   sc->sc_regs[15] = tst->arch.vex.guest_r15;
   sc->sc_regs[16] = tst->arch.vex.guest_r16;
   sc->sc_regs[17] = tst->arch.vex.guest_r17;
   sc->sc_regs[18] = tst->arch.vex.guest_r18;
   sc->sc_regs[19] = tst->arch.vex.guest_r19;
   sc->sc_regs[20] = tst->arch.vex.guest_r20;
   sc->sc_regs[21] = tst->arch.vex.guest_r21;
   sc->sc_regs[22] = tst->arch.vex.guest_r22;
   sc->sc_regs[23] = tst->arch.vex.guest_r23;
   sc->sc_regs[24] = tst->arch.vex.guest_r24;
   sc->sc_regs[25] = tst->arch.vex.guest_r25;
   sc->sc_regs[26] = tst->arch.vex.guest_r26;
   sc->sc_regs[27] = tst->arch.vex.guest_r27;
   sc->sc_regs[28] = tst->arch.vex.guest_r28;
   sc->sc_regs[29] = tst->arch.vex.guest_r29;
   sc->sc_regs[30] = tst->arch.vex.guest_r30;
   sc->sc_regs[31] = tst->arch.vex.guest_r31;
   sc->sc_pc = tst->arch.vex.guest_PC;
   sc->sc_mdhi = tst->arch.vex.guest_HI;
   sc->sc_mdlo = tst->arch.vex.guest_LO;
}

/* EXPORTED */
void VG_(sigframe_create) ( ThreadId tid,
                            Addr sp_top_of_frame,
                            const vki_siginfo_t *siginfo,
                            const struct vki_ucontext *siguc,
                            void *handler,
                            UInt flags,
                            const vki_sigset_t *mask,
                            void *restorer )
{
   Addr sp;
   ThreadState* tst = VG_(get_ThreadState)(tid);
   Int sigNo = siginfo->si_signo;
   struct vg_sig_private *priv;
   /* Stack must be 16-byte aligned */
   sp_top_of_frame &= ~0xf;

   sp = sp_top_of_frame - sizeof(struct rt_sigframe);

   tst = VG_(get_ThreadState)(tid);
   if (!extend(tst, sp, sp_top_of_frame - sp))
      return;

   sp = VG_ROUNDDN(sp, 16);

   struct rt_sigframe *frame = (struct rt_sigframe *)sp;
   struct vki_ucontext *ucp = &frame->rs_uc;
   if (VG_(clo_trace_signals))
      VG_(printf)("rt_sigframe\n");
   /* Create siginfo. */
   VG_TRACK(pre_mem_write, Vg_CoreSignal, tid, "signal frame siginfo",
            (Addr)&frame->rs_info, sizeof(frame->rs_info));

   VG_(memcpy)(&frame->rs_info, siginfo, sizeof(*siginfo));

   VG_TRACK(post_mem_write, Vg_CoreSignal, tid,
            (Addr)&frame->rs_info, sizeof(frame->rs_info));

   /* Create the ucontext. */
   VG_TRACK(pre_mem_write, Vg_CoreSignal, tid, "signal frame ucontext",
            (Addr)ucp, offsetof(struct vki_ucontext, uc_mcontext));

   ucp->uc_flags = 0;
   ucp->uc_link = 0;
   ucp->uc_stack = tst->altstack;

   VG_TRACK(post_mem_write, Vg_CoreSignal, tid, (Addr)ucp,
            offsetof(struct vki_ucontext, uc_mcontext));

   struct vki_sigcontext *scp = &(frame->rs_uc.uc_mcontext);
   setup_sigcontext(tst, &(scp), siginfo);
   ucp->uc_sigmask = tst->sig_mask;
   priv = &frame->priv;

   /* Arguments to signal handler:

      a0 = signal number
      a1 = 0 (should be cause)
      a2 = pointer to ucontext

      $25 and c0_epc point to the signal handler, $29 points to
      the struct rt_sigframe. */

   tst->arch.vex.guest_r4 = siginfo->si_signo;
   tst->arch.vex.guest_r5 = (Addr) &frame->rs_info;
   tst->arch.vex.guest_r6 = (Addr) &frame->rs_uc;
   tst->arch.vex.guest_r29 = (Addr) frame;
   tst->arch.vex.guest_r25 = (Addr) handler;

   if (flags & VKI_SA_RESTORER) 
      tst->arch.vex.guest_r31 = (Addr) restorer;
   else 
      tst->arch.vex.guest_r31 = (Addr)&VG_(mips64_linux_SUBST_FOR_rt_sigreturn);

   priv->magicPI       = 0x31415927;
   priv->sigNo_private = sigNo;
   priv->vex_shadow1   = tst->arch.vex_shadow1;
   priv->vex_shadow2   = tst->arch.vex_shadow2;
   /* Set the thread so it will next run the handler. */
   VG_TRACK( post_reg_write, Vg_CoreSignal, tid, VG_O_STACK_PTR, sizeof(Addr));
   if (VG_(clo_trace_signals))
      VG_(printf)("handler = %p\n", handler);
   tst->arch.vex.guest_PC = (Addr) handler;
   /* This thread needs to be marked runnable, but we leave that
      the caller to do. */
}

/* EXPORTED */
void VG_(sigframe_destroy) ( ThreadId tid, Bool isRT )
{
   ThreadState *tst;
   struct vg_sig_private *priv1;
   Addr sp;
   UInt frame_size;
   struct vki_sigcontext *mc;
   Int sigNo;

   vg_assert(VG_(is_valid_tid)(tid));
   tst = VG_(get_ThreadState)(tid);
   sp   = tst->arch.vex.guest_r29;
   struct rt_sigframe *frame = (struct rt_sigframe *)sp;
   struct vki_ucontext *ucp = &frame->rs_uc;
   frame_size = sizeof(*frame);
   mc = &ucp->uc_mcontext;
   tst->sig_mask = ucp->uc_sigmask;
   tst->tmp_sig_mask = ucp->uc_sigmask;
   priv1 = &frame->priv;
   sigNo = priv1->sigNo_private;
   vg_assert(priv1->magicPI == 0x31415927);
   /* restore regs */
   tst->arch.vex.guest_r1 = mc->sc_regs[1];
   tst->arch.vex.guest_r2 = mc->sc_regs[2];
   tst->arch.vex.guest_r3 = mc->sc_regs[3];
   tst->arch.vex.guest_r4 = mc->sc_regs[4];
   tst->arch.vex.guest_r5 = mc->sc_regs[5];
   tst->arch.vex.guest_r6 = mc->sc_regs[6];
   tst->arch.vex.guest_r7 = mc->sc_regs[7];
   tst->arch.vex.guest_r8 = mc->sc_regs[8];
   tst->arch.vex.guest_r9 = mc->sc_regs[9];
   tst->arch.vex.guest_r10 = mc->sc_regs[10];
   tst->arch.vex.guest_r11 = mc->sc_regs[11];
   tst->arch.vex.guest_r12 = mc->sc_regs[12];
   tst->arch.vex.guest_r13= mc->sc_regs[13];
   tst->arch.vex.guest_r14 = mc->sc_regs[14];
   tst->arch.vex.guest_r15 = mc->sc_regs[15];
   tst->arch.vex.guest_r16 = mc->sc_regs[16];
   tst->arch.vex.guest_r17 = mc->sc_regs[17];
   tst->arch.vex.guest_r18 = mc->sc_regs[18];
   tst->arch.vex.guest_r19 = mc->sc_regs[19];
   tst->arch.vex.guest_r20 = mc->sc_regs[20];
   tst->arch.vex.guest_r21 = mc->sc_regs[21];
   tst->arch.vex.guest_r22 = mc->sc_regs[22];
   tst->arch.vex.guest_r23 = mc->sc_regs[23];
   tst->arch.vex.guest_r24 = mc->sc_regs[24];
   tst->arch.vex.guest_r25 = mc->sc_regs[25];
   tst->arch.vex.guest_r26 = mc->sc_regs[26];
   tst->arch.vex.guest_r27 = mc->sc_regs[27];
   tst->arch.vex.guest_r28 = mc->sc_regs[28];
   tst->arch.vex.guest_r30 = mc->sc_regs[30];
   tst->arch.vex.guest_PC = mc->sc_pc;
   tst->arch.vex.guest_r31 = mc->sc_regs[31];
   tst->arch.vex.guest_r29 = mc->sc_regs[29];

   tst->arch.vex.guest_HI = mc->sc_mdhi;
   tst->arch.vex.guest_LO = mc->sc_mdlo;
   tst->arch.vex_shadow1 = priv1->vex_shadow1;
   tst->arch.vex_shadow2 = priv1->vex_shadow2;

   VG_TRACK(die_mem_stack_signal, sp, frame_size);
   if (VG_(clo_trace_signals))
      VG_(message)(Vg_DebugMsg,
         "VG_(signal_return) (thread %d): isRT=%d valid magic; EIP=%#llx\n",
         tid, isRT, tst->arch.vex.guest_PC);
   /* tell the tools */
   VG_TRACK( post_deliver_signal, tid, sigNo );
}

#endif /* defined(VGP_mips64_linux) */

/*--------------------------------------------------------------------*/
/*--- end                                  sigframe-mips64-linux.c ---*/
/*--------------------------------------------------------------------*/