[thirdparty/gcc.git] / libgcc / config / rs6000 / linux-unwind.h

/* DWARF2 EH unwinding support for PowerPC and PowerPC64 Linux.
   Copyright (C) 2004-2023 Free Software Foundation, Inc.

   This file is part of GCC.

   GCC 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 3, or (at your
   option) any later version.

   GCC 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.

   Under Section 7 of GPL version 3, you are granted additional
   permissions described in the GCC Runtime Library Exception, version
   3.1, as published by the Free Software Foundation.

   You should have received a copy of the GNU General Public License and
   a copy of the GCC Runtime Library Exception along with this program;
   see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
   <http://www.gnu.org/licenses/>.  */

#define R_LR		65
#define R_CR2		70
#define R_CR3		71
#define R_CR4		72
#define R_VR0		77
#define R_VRSAVE	109

#ifdef __powerpc64__
#if _CALL_ELF == 2
#define TOC_SAVE_SLOT	24
#else
#define TOC_SAVE_SLOT	40
#endif
#endif

struct gcc_vregs
{
  __attribute__ ((vector_size (16))) int vr[32];
#ifdef __powerpc64__
  unsigned int pad1[3];
  unsigned int vscr;
  unsigned int vsave;
  unsigned int pad2[3];
#else
  unsigned int vsave;
  unsigned int pad[2];
  unsigned int vscr;
#endif
};

struct gcc_regs
{
  unsigned long gpr[32];
  unsigned long nip;
  unsigned long msr;
  unsigned long orig_gpr3;
  unsigned long ctr;
  unsigned long link;
  unsigned long xer;
  unsigned long ccr;
  unsigned long softe;
  unsigned long trap;
  unsigned long dar;
  unsigned long dsisr;
  unsigned long result;
  unsigned long pad1[4];
  double fpr[32];
  unsigned int pad2;
  unsigned int fpscr;
#ifdef __powerpc64__
  struct gcc_vregs *vp;
#else
  unsigned int pad3[2];
#endif
  struct gcc_vregs vregs;
};

struct gcc_ucontext
{
#ifdef __powerpc64__
  unsigned long pad[28];
#else
  unsigned long pad[12];
#endif
  struct gcc_regs *regs;
  struct gcc_regs rsave;
};

#ifdef __powerpc64__

enum { SIGNAL_FRAMESIZE = 128 };

struct rt_sigframe {
  char gap[SIGNAL_FRAMESIZE];
  struct gcc_ucontext uc;
  unsigned long pad[2];
  int tramp[6];
  void *pinfo;
  struct gcc_ucontext *puc;
};

/* If PC is at a sigreturn trampoline, return a pointer to the
   regs.  Otherwise return NULL.  */

static struct gcc_regs *
get_regs (struct _Unwind_Context *context)
{
  const unsigned int *pc = context->ra;

  /* addi r1, r1, 128; li r0, 0x0077; sc  (sigreturn) */
  /* addi r1, r1, 128; li r0, 0x00AC; sc  (rt_sigreturn) */
  if (pc[0] != 0x38210000 + SIGNAL_FRAMESIZE || pc[2] != 0x44000002)
    return NULL;
  if (pc[1] == 0x38000077)
    {
      struct sigframe {
	char gap[SIGNAL_FRAMESIZE];
	unsigned long pad[7];
	struct gcc_regs *regs;
      } *frame = (struct sigframe *) context->cfa;
      return frame->regs;
    }
  else if (pc[1] == 0x380000AC)
    {
#if _CALL_ELF != 2
      /* These old kernel versions never supported ELFv2.  */
      /* This works for 2.4 kernels, but not for 2.6 kernels with vdso
	 because pc isn't pointing into the stack.  Can be removed when
	 no one is running 2.4.19 or 2.4.20, the first two ppc64
	 kernels released.  */
      const struct rt_sigframe_24 {
	int tramp[6];
	void *pinfo;
	struct gcc_ucontext *puc;
      } *frame24 = (const struct rt_sigframe_24 *) context->ra;

      /* Test for magic value in *puc of vdso.  */
      if ((long) frame24->puc != -21 * 8)
	return frame24->puc->regs;
      else
#endif
	{
	  /* This works for 2.4.21 and later kernels.  */
	  struct rt_sigframe *frame = (struct rt_sigframe *) context->cfa;
	  return frame->uc.regs;
	}
    }
  return NULL;
}

#else  /* !__powerpc64__ */

enum { SIGNAL_FRAMESIZE = 64 };

struct rt_sigframe {
  char gap[SIGNAL_FRAMESIZE + 16];
  char siginfo[128];
  struct gcc_ucontext uc;
};

static struct gcc_regs *
get_regs (struct _Unwind_Context *context)
{
  const unsigned int *pc = context->ra;

  /* li r0, 0x7777; sc  (sigreturn old)  */
  /* li r0, 0x0077; sc  (sigreturn new)  */
  /* li r0, 0x6666; sc  (rt_sigreturn old)  */
  /* li r0, 0x00AC; sc  (rt_sigreturn new)  */
  if (pc[1] != 0x44000002)
    return NULL;
  if (pc[0] == 0x38007777 || pc[0] == 0x38000077)
    {
      struct sigframe {
	char gap[SIGNAL_FRAMESIZE];
	unsigned long pad[7];
	struct gcc_regs *regs;
      } *frame = (struct sigframe *) context->cfa;
      return frame->regs;
    }
  else if (pc[0] == 0x38006666 || pc[0] == 0x380000AC)
    {
      struct rt_sigframe *frame = (struct rt_sigframe *) context->cfa;
      return frame->uc.regs;
    }
  return NULL;
}
#endif

/* Do code reading to identify a signal frame, and set the frame
   state data appropriately.  See unwind-dw2.c for the structs.  */

#define MD_FALLBACK_FRAME_STATE_FOR ppc_fallback_frame_state

static _Unwind_Reason_Code
ppc_fallback_frame_state (struct _Unwind_Context *context,
			  _Unwind_FrameState *fs)
{
  struct gcc_regs *regs = get_regs (context);
  struct gcc_vregs *vregs;
  long cr_offset;
  long new_cfa;
  int i;

  if (regs == NULL)
    return _URC_NORMAL_STOP;

  new_cfa = regs->gpr[__LIBGCC_STACK_POINTER_REGNUM__];
  fs->regs.cfa_how = CFA_REG_OFFSET;
  fs->regs.cfa_reg = __LIBGCC_STACK_POINTER_REGNUM__;
  fs->regs.cfa_offset = new_cfa - (long) context->cfa;

#ifdef __powerpc64__
  fs->regs.how[2] = REG_SAVED_OFFSET;
  fs->regs.reg[2].loc.offset = (long) &regs->gpr[2] - new_cfa;
#endif
  for (i = 14; i < 32; i++)
    {
      fs->regs.how[i] = REG_SAVED_OFFSET;
      fs->regs.reg[i].loc.offset = (long) &regs->gpr[i] - new_cfa;
    }

  /* The CR is saved in the low 32 bits of regs->ccr.  */
  cr_offset = (long) &regs->ccr - new_cfa;
#ifndef __LITTLE_ENDIAN__
  cr_offset += sizeof (long) - 4;
#endif
  /* In the ELFv1 ABI, CR2 stands in for the whole CR.  */
  fs->regs.how[R_CR2] = REG_SAVED_OFFSET;
  fs->regs.reg[R_CR2].loc.offset = cr_offset;
#if _CALL_ELF == 2
  /* In the ELFv2 ABI, every CR field has a separate CFI entry.  */
  fs->regs.how[R_CR3] = REG_SAVED_OFFSET;
  fs->regs.reg[R_CR3].loc.offset = cr_offset;
  fs->regs.how[R_CR4] = REG_SAVED_OFFSET;
  fs->regs.reg[R_CR4].loc.offset = cr_offset;
#endif

  fs->regs.how[R_LR] = REG_SAVED_OFFSET;
  fs->regs.reg[R_LR].loc.offset = (long) &regs->link - new_cfa;

  fs->regs.how[ARG_POINTER_REGNUM] = REG_SAVED_OFFSET;
  fs->regs.reg[ARG_POINTER_REGNUM].loc.offset = (long) &regs->nip - new_cfa;
  fs->retaddr_column = ARG_POINTER_REGNUM;
  fs->signal_frame = 1;

  /* If we have a FPU...  */
  for (i = 14; i < 32; i++)
    {
      fs->regs.how[i + 32] = REG_SAVED_OFFSET;
      fs->regs.reg[i + 32].loc.offset = (long) &regs->fpr[i] - new_cfa;
    }

  /* If we have a VMX unit...  */
#ifdef __powerpc64__
  vregs = regs->vp;
#else
  vregs = &regs->vregs;
#endif
  if (regs->msr & (1 << 25))
    {
      for (i = 20; i < 32; i++)
	{
	  fs->regs.how[i + R_VR0] = REG_SAVED_OFFSET;
	  fs->regs.reg[i + R_VR0].loc.offset = (long) &vregs->vr[i] - new_cfa;
	}
    }

  fs->regs.how[R_VRSAVE] = REG_SAVED_OFFSET;
  fs->regs.reg[R_VRSAVE].loc.offset = (long) &vregs->vsave - new_cfa;

  /* If we have SPE register high-parts... we check at compile-time to
     avoid expanding the code for all other PowerPC.  */
#ifdef __SPE__
  for (i = 14; i < 32; i++)
    {
      fs->regs.how[i + FIRST_SPE_HIGH_REGNO - 4] = REG_SAVED_OFFSET;
      fs->regs.reg[i + FIRST_SPE_HIGH_REGNO - 4].loc.offset
	= (long) &regs->vregs - new_cfa + 4 * i;
    }
#endif

  return _URC_NO_REASON;
}

#define MD_FROB_UPDATE_CONTEXT frob_update_context

static void
frob_update_context (struct _Unwind_Context *context, _Unwind_FrameState *fs ATTRIBUTE_UNUSED)
{
  const unsigned int *pc = (const unsigned int *) context->ra;

  /* Fix up for 2.6.12 - 2.6.16 Linux kernels that have vDSO, but don't
     have S flag in it.  */
#ifdef __powerpc64__
  /* addi r1, r1, 128; li r0, 0x0077; sc  (sigreturn) */
  /* addi r1, r1, 128; li r0, 0x00AC; sc  (rt_sigreturn) */
  if (pc[0] == 0x38210000 + SIGNAL_FRAMESIZE
      && (pc[1] == 0x38000077 || pc[1] == 0x380000AC)
      && pc[2] == 0x44000002)
    _Unwind_SetSignalFrame (context, 1);
#else
  /* li r0, 0x7777; sc  (sigreturn old)  */
  /* li r0, 0x0077; sc  (sigreturn new)  */
  /* li r0, 0x6666; sc  (rt_sigreturn old)  */
  /* li r0, 0x00AC; sc  (rt_sigreturn new)  */
  if ((pc[0] == 0x38007777 || pc[0] == 0x38000077
       || pc[0] == 0x38006666 || pc[0] == 0x380000AC)
      && pc[1] == 0x44000002)
    _Unwind_SetSignalFrame (context, 1);
#endif

#ifdef __powerpc64__
  if (fs->regs.how[2] == REG_UNSAVED)
    {
      /* If the current unwind info (FS) does not contain explicit info
	 saving R2, then we have to do a minor amount of code reading to
	 figure out if it was saved.  The big problem here is that the
	 code that does the save/restore is generated by the linker, so
	 we have no good way to determine at compile time what to do.  */
      if (pc[0] == 0xF8410000 + TOC_SAVE_SLOT
#if _CALL_ELF != 2
	  /* The ELFv2 linker never generates the old PLT stub form.  */
	  || ((pc[0] & 0xFFFF0000) == 0x3D820000
	      && pc[1] == 0xF8410000 + TOC_SAVE_SLOT)
#endif
	  )
	{
	  /* We are in a plt call stub or r2 adjusting long branch stub,
	     before r2 has been saved.  Keep REG_UNSAVED.  */
	}
      else
	{
	  unsigned int *insn
	    = (unsigned int *) _Unwind_GetGR (context, R_LR);
	  if (insn && *insn == 0xE8410000 + TOC_SAVE_SLOT)
	    _Unwind_SetGRPtr (context, 2, context->cfa + TOC_SAVE_SLOT);
#if _CALL_ELF != 2
	  /* ELFv2 does not use this function pointer call sequence.  */
	  else if (pc[0] == 0x4E800421
		   && pc[1] == 0xE8410000 + TOC_SAVE_SLOT)
	    {
	      /* We are at the bctrl instruction in a call via function
		 pointer.  gcc always emits the load of the new R2 just
		 before the bctrl so this is the first and only place
		 we need to use the stored R2.  */
	      _Unwind_Word sp = _Unwind_GetGR (context, 1);
	      _Unwind_SetGRPtr (context, 2, (void *)(sp + TOC_SAVE_SLOT));
	    }
#endif
	}
    }
#endif
}

#define MD_BACKCHAIN_FALLBACK ppc_backchain_fallback

struct trace_arg
{
  /* Stores the list of addresses.  */
  void **array;
  struct unwind_link *unwind_link;
  _Unwind_Word cfa;
  /* Number of addresses currently stored.  */
  int count;
  /* Maximum number of addresses.  */
  int size;
};

/* This is the stack layout we see with every stack frame.
   Note that every routine is required by the ABI to lay out the stack
   like this.

	    +----------------+        +-----------------+
    %r1  -> | previous frame--------> | previous frame--->...  --> NULL
	    |                |        |                 |
	    | cr save        |        | cr save	        |
	    |                |        |                 |
	    | (unused)       |        | lr save         |
	    +----------------+        +-----------------+

  The CR save is only present on 64-bit ABIs.
*/
struct frame_layout
{
  struct frame_layout *backchain;
#ifdef __powerpc64__
  long int cr_save;
#endif
  void *lr_save;
};


static void
ppc_backchain_fallback (struct _Unwind_Context *context, void *a)
{
  struct frame_layout *current;
  struct trace_arg *arg = a;
  int count;

  /* Get the last address computed.  */
  current = context->cfa;

  /* If the trace CFA is not the context CFA the backtrace is done.  */
  if (arg == NULL || arg->cfa != current)
	return;

  /* Start with next address.  */
  current = current->backchain;

  for (count = arg->count; current != NULL; current = current->backchain)
    {
      arg->array[count] = current->lr_save;

      /* Check if the symbol is the signal trampoline and get the interrupted
	 symbol address from the trampoline saved area.  */
      context->ra = current->lr_save;
      if (current->lr_save && get_regs (context))
	{
	  struct rt_sigframe *sigframe = (struct rt_sigframe *) current;
	  if (count + 1 == arg->size)
	    break;
	  arg->array[++count] = (void *) sigframe->uc.rsave.nip;
	  current = (void *) sigframe->uc.rsave.gpr[1];
	}
      if (count++ >= arg->size)
	break;
    }

  arg->count = count-1;
}
Commit	Line	Data
8662eb14	1	/* DWARF2 EH unwinding support for PowerPC and PowerPC64 Linux.
83ffe9cd	2	Copyright (C) 2004-2023 Free Software Foundation, Inc.
8662eb14 AM	3
	4	This file is part of GCC.
	5
	6	GCC is free software; you can redistribute it and/or modify it
	7	under the terms of the GNU General Public License as published
748086b7	8	by the Free Software Foundation; either version 3, or (at your
8662eb14 AM	9	option) any later version.
	10
	11	GCC is distributed in the hope that it will be useful, but WITHOUT
	12	ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
	13	or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
	14	License for more details.
	15
748086b7 JJ	16	Under Section 7 of GPL version 3, you are granted additional
	17	permissions described in the GCC Runtime Library Exception, version
	18	3.1, as published by the Free Software Foundation.
8662eb14	19
748086b7 JJ	20	You should have received a copy of the GNU General Public License and
	21	a copy of the GCC Runtime Library Exception along with this program;
	22	see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
	23	<http://www.gnu.org/licenses/>. */
8662eb14	24
1de43f85 DE	25	#define R_LR 65
1de43f85 DE	26	#define R_CR2 70
b54214fe UW	27	#define R_CR3 71
b54214fe UW	28	#define R_CR4 72
1de43f85 DE	29	#define R_VR0 77
1de43f85 DE	30	#define R_VRSAVE 109
1de43f85	31
b54214fe UW	32	#ifdef __powerpc64__
	33	#if _CALL_ELF == 2
	34	#define TOC_SAVE_SLOT 24
	35	#else
	36	#define TOC_SAVE_SLOT 40
	37	#endif
	38	#endif
	39
a7a52913 AM	40	struct gcc_vregs
	41	{
	42	__attribute__ ((vector_size (16))) int vr[32];
	43	#ifdef __powerpc64__
	44	unsigned int pad1[3];
	45	unsigned int vscr;
	46	unsigned int vsave;
	47	unsigned int pad2[3];
	48	#else
	49	unsigned int vsave;
	50	unsigned int pad[2];
	51	unsigned int vscr;
	52	#endif
	53	};
	54
	55	struct gcc_regs
8662eb14 AM	56	{
	57	unsigned long gpr[32];
	58	unsigned long nip;
	59	unsigned long msr;
	60	unsigned long orig_gpr3;
	61	unsigned long ctr;
	62	unsigned long link;
43e7c6a4 AM	63	unsigned long xer;
43e7c6a4 AM	64	unsigned long ccr;
a7a52913 AM	65	unsigned long softe;
	66	unsigned long trap;
	67	unsigned long dar;
	68	unsigned long dsisr;
	69	unsigned long result;
	70	unsigned long pad1[4];
	71	double fpr[32];
	72	unsigned int pad2;
	73	unsigned int fpscr;
	74	#ifdef __powerpc64__
	75	struct gcc_vregs *vp;
	76	#else
	77	unsigned int pad3[2];
	78	#endif
	79	struct gcc_vregs vregs;
8662eb14 AM	80	};
	81
	82	struct gcc_ucontext
	83	{
	84	#ifdef __powerpc64__
a7a52913	85	unsigned long pad[28];
8662eb14	86	#else
a7a52913	87	unsigned long pad[12];
8662eb14	88	#endif
a7a52913 AM	89	struct gcc_regs *regs;
a7a52913 AM	90	struct gcc_regs rsave;
8662eb14 AM	91	};
	92
	93	#ifdef __powerpc64__
	94
	95	enum { SIGNAL_FRAMESIZE = 128 };
	96
b7561b5d RMZ	97	struct rt_sigframe {
	98	char gap[SIGNAL_FRAMESIZE];
	99	struct gcc_ucontext uc;
	100	unsigned long pad[2];
	101	int tramp[6];
	102	void *pinfo;
	103	struct gcc_ucontext *puc;
	104	};
	105
8662eb14	106	/* If PC is at a sigreturn trampoline, return a pointer to the
a7a52913	107	regs. Otherwise return NULL. */
8662eb14	108
a7a52913 AM	109	static struct gcc_regs *
a7a52913 AM	110	get_regs (struct _Unwind_Context *context)
8662eb14	111	{
9a461028	112	const unsigned int *pc = context->ra;
8662eb14 AM	113
	114	/* addi r1, r1, 128; li r0, 0x0077; sc (sigreturn) */
	115	/* addi r1, r1, 128; li r0, 0x00AC; sc (rt_sigreturn) */
9a461028	116	if (pc[0] != 0x38210000 + SIGNAL_FRAMESIZE \|\| pc[2] != 0x44000002)
8662eb14	117	return NULL;
9a461028	118	if (pc[1] == 0x38000077)
8662eb14 AM	119	{
	120	struct sigframe {
	121	char gap[SIGNAL_FRAMESIZE];
a7a52913 AM	122	unsigned long pad[7];
	123	struct gcc_regs *regs;
	124	} frame = (struct sigframe ) context->cfa;
	125	return frame->regs;
8662eb14	126	}
9a461028	127	else if (pc[1] == 0x380000AC)
8662eb14	128	{
b54214fe UW	129	#if _CALL_ELF != 2
b54214fe UW	130	/* These old kernel versions never supported ELFv2. */
a7a52913 AM	131	/* This works for 2.4 kernels, but not for 2.6 kernels with vdso
	132	because pc isn't pointing into the stack. Can be removed when
	133	no one is running 2.4.19 or 2.4.20, the first two ppc64
	134	kernels released. */
9a461028	135	const struct rt_sigframe_24 {
8662eb14 AM	136	int tramp[6];
	137	void *pinfo;
	138	struct gcc_ucontext *puc;
9a461028	139	} frame24 = (const struct rt_sigframe_24 ) context->ra;
a7a52913 AM	140
	141	/* Test for magic value in puc of vdso. /
	142	if ((long) frame24->puc != -21 * 8)
	143	return frame24->puc->regs;
	144	else
b54214fe	145	#endif
a7a52913 AM	146	{
a7a52913 AM	147	/* This works for 2.4.21 and later kernels. */
b7561b5d	148	struct rt_sigframe frame = (struct rt_sigframe ) context->cfa;
a7a52913 AM	149	return frame->uc.regs;
a7a52913 AM	150	}
8662eb14 AM	151	}
	152	return NULL;
	153	}
	154
	155	#else /* !__powerpc64__ */
	156
	157	enum { SIGNAL_FRAMESIZE = 64 };
	158
b7561b5d RMZ	159	struct rt_sigframe {
	160	char gap[SIGNAL_FRAMESIZE + 16];
	161	char siginfo[128];
	162	struct gcc_ucontext uc;
	163	};
	164
a7a52913 AM	165	static struct gcc_regs *
a7a52913 AM	166	get_regs (struct _Unwind_Context *context)
8662eb14	167	{
9a461028	168	const unsigned int *pc = context->ra;
8662eb14 AM	169
	170	/* li r0, 0x7777; sc (sigreturn old) */
	171	/* li r0, 0x0077; sc (sigreturn new) */
	172	/* li r0, 0x6666; sc (rt_sigreturn old) */
	173	/* li r0, 0x00AC; sc (rt_sigreturn new) */
9a461028	174	if (pc[1] != 0x44000002)
8662eb14	175	return NULL;
9a461028	176	if (pc[0] == 0x38007777 \|\| pc[0] == 0x38000077)
8662eb14 AM	177	{
	178	struct sigframe {
	179	char gap[SIGNAL_FRAMESIZE];
a7a52913 AM	180	unsigned long pad[7];
	181	struct gcc_regs *regs;
	182	} frame = (struct sigframe ) context->cfa;
	183	return frame->regs;
8662eb14	184	}
9a461028	185	else if (pc[0] == 0x38006666 \|\| pc[0] == 0x380000AC)
8662eb14	186	{
b7561b5d	187	struct rt_sigframe frame = (struct rt_sigframe ) context->cfa;
a7a52913	188	return frame->uc.regs;
8662eb14 AM	189	}
	190	return NULL;
	191	}
	192	#endif
	193
	194	/* Do code reading to identify a signal frame, and set the frame
	195	state data appropriately. See unwind-dw2.c for the structs. */
	196
	197	#define MD_FALLBACK_FRAME_STATE_FOR ppc_fallback_frame_state
	198
	199	static _Unwind_Reason_Code
	200	ppc_fallback_frame_state (struct _Unwind_Context *context,
	201	_Unwind_FrameState *fs)
	202	{
a7a52913	203	struct gcc_regs *regs = get_regs (context);
110207ad	204	struct gcc_vregs *vregs;
13e0981a	205	long cr_offset;
8662eb14 AM	206	long new_cfa;
	207	int i;
	208
a7a52913	209	if (regs == NULL)
b7561b5d	210	return _URC_NORMAL_STOP;
8662eb14	211
53d68b9f	212	new_cfa = regs->gpr[__LIBGCC_STACK_POINTER_REGNUM__];
6673f90b	213	fs->regs.cfa_how = CFA_REG_OFFSET;
53d68b9f	214	fs->regs.cfa_reg = __LIBGCC_STACK_POINTER_REGNUM__;
6673f90b	215	fs->regs.cfa_offset = new_cfa - (long) context->cfa;
8662eb14	216
110207ad	217	#ifdef __powerpc64__
146e4591	218	fs->regs.how[2] = REG_SAVED_OFFSET;
110207ad AM	219	fs->regs.reg[2].loc.offset = (long) &regs->gpr[2] - new_cfa;
	220	#endif
	221	for (i = 14; i < 32; i++)
	222	{
146e4591	223	fs->regs.how[i] = REG_SAVED_OFFSET;
110207ad AM	224	fs->regs.reg[i].loc.offset = (long) &regs->gpr[i] - new_cfa;
110207ad AM	225	}
8662eb14	226
13e0981a UW	227	/* The CR is saved in the low 32 bits of regs->ccr. */
	228	cr_offset = (long) &regs->ccr - new_cfa;
	229	#ifndef __LITTLE_ENDIAN__
	230	cr_offset += sizeof (long) - 4;
	231	#endif
b54214fe	232	/* In the ELFv1 ABI, CR2 stands in for the whole CR. */
146e4591	233	fs->regs.how[R_CR2] = REG_SAVED_OFFSET;
13e0981a	234	fs->regs.reg[R_CR2].loc.offset = cr_offset;
b54214fe UW	235	#if _CALL_ELF == 2
b54214fe UW	236	/* In the ELFv2 ABI, every CR field has a separate CFI entry. */
146e4591	237	fs->regs.how[R_CR3] = REG_SAVED_OFFSET;
b54214fe	238	fs->regs.reg[R_CR3].loc.offset = cr_offset;
146e4591	239	fs->regs.how[R_CR4] = REG_SAVED_OFFSET;
b54214fe UW	240	fs->regs.reg[R_CR4].loc.offset = cr_offset;
b54214fe UW	241	#endif
43e7c6a4	242
146e4591	243	fs->regs.how[R_LR] = REG_SAVED_OFFSET;
1de43f85	244	fs->regs.reg[R_LR].loc.offset = (long) &regs->link - new_cfa;
8662eb14	245
146e4591	246	fs->regs.how[ARG_POINTER_REGNUM] = REG_SAVED_OFFSET;
a7a52913	247	fs->regs.reg[ARG_POINTER_REGNUM].loc.offset = (long) &regs->nip - new_cfa;
8662eb14	248	fs->retaddr_column = ARG_POINTER_REGNUM;
754e45a8	249	fs->signal_frame = 1;
a7a52913	250
110207ad AM	251	/* If we have a FPU... */
110207ad AM	252	for (i = 14; i < 32; i++)
a7a52913	253	{
146e4591	254	fs->regs.how[i + 32] = REG_SAVED_OFFSET;
110207ad	255	fs->regs.reg[i + 32].loc.offset = (long) &regs->fpr[i] - new_cfa;
a7a52913 AM	256	}
a7a52913 AM	257
a7a52913	258	/* If we have a VMX unit... */
a7a52913	259	#ifdef __powerpc64__
110207ad	260	vregs = regs->vp;
a7a52913	261	#else
110207ad	262	vregs = &regs->vregs;
a7a52913	263	#endif
110207ad AM	264	if (regs->msr & (1 << 25))
	265	{
	266	for (i = 20; i < 32; i++)
a7a52913	267	{
146e4591	268	fs->regs.how[i + R_VR0] = REG_SAVED_OFFSET;
110207ad	269	fs->regs.reg[i + R_VR0].loc.offset = (long) &vregs->vr[i] - new_cfa;
a7a52913	270	}
a7a52913 AM	271	}
a7a52913 AM	272
146e4591	273	fs->regs.how[R_VRSAVE] = REG_SAVED_OFFSET;
110207ad AM	274	fs->regs.reg[R_VRSAVE].loc.offset = (long) &vregs->vsave - new_cfa;
110207ad AM	275
37ea0b7e JM	276	/* If we have SPE register high-parts... we check at compile-time to
	277	avoid expanding the code for all other PowerPC. */
	278	#ifdef __SPE__
110207ad	279	for (i = 14; i < 32; i++)
37ea0b7e	280	{
146e4591	281	fs->regs.how[i + FIRST_SPE_HIGH_REGNO - 4] = REG_SAVED_OFFSET;
23742a9e	282	fs->regs.reg[i + FIRST_SPE_HIGH_REGNO - 4].loc.offset
37ea0b7e JM	283	= (long) &regs->vregs - new_cfa + 4 * i;
	284	}
	285	#endif
	286
8662eb14 AM	287	return _URC_NO_REASON;
8662eb14 AM	288	}
754e45a8 JJ	289
	290	#define MD_FROB_UPDATE_CONTEXT frob_update_context
	291
	292	static void
75334508	293	frob_update_context (struct _Unwind_Context context, _Unwind_FrameState fs ATTRIBUTE_UNUSED)
754e45a8 JJ	294	{
	295	const unsigned int pc = (const unsigned int ) context->ra;
	296
	297	/* Fix up for 2.6.12 - 2.6.16 Linux kernels that have vDSO, but don't
	298	have S flag in it. */
	299	#ifdef __powerpc64__
	300	/* addi r1, r1, 128; li r0, 0x0077; sc (sigreturn) */
	301	/* addi r1, r1, 128; li r0, 0x00AC; sc (rt_sigreturn) */
	302	if (pc[0] == 0x38210000 + SIGNAL_FRAMESIZE
	303	&& (pc[1] == 0x38000077 \|\| pc[1] == 0x380000AC)
	304	&& pc[2] == 0x44000002)
f8e7718c	305	_Unwind_SetSignalFrame (context, 1);
754e45a8 JJ	306	#else
	307	/* li r0, 0x7777; sc (sigreturn old) */
	308	/* li r0, 0x0077; sc (sigreturn new) */
	309	/* li r0, 0x6666; sc (rt_sigreturn old) */
	310	/* li r0, 0x00AC; sc (rt_sigreturn new) */
	311	if ((pc[0] == 0x38007777 \|\| pc[0] == 0x38000077
	312	\|\| pc[0] == 0x38006666 \|\| pc[0] == 0x380000AC)
	313	&& pc[1] == 0x44000002)
f8e7718c	314	_Unwind_SetSignalFrame (context, 1);
754e45a8 JJ	315	#endif
	316
	317	#ifdef __powerpc64__
146e4591	318	if (fs->regs.how[2] == REG_UNSAVED)
754e45a8 JJ	319	{
	320	/* If the current unwind info (FS) does not contain explicit info
	321	saving R2, then we have to do a minor amount of code reading to
	322	figure out if it was saved. The big problem here is that the
	323	code that does the save/restore is generated by the linker, so
	324	we have no good way to determine at compile time what to do. */
b54214fe UW	325	if (pc[0] == 0xF8410000 + TOC_SAVE_SLOT
	326	#if _CALL_ELF != 2
	327	/* The ELFv2 linker never generates the old PLT stub form. */
2374a88a	328	\|\| ((pc[0] & 0xFFFF0000) == 0x3D820000
b54214fe UW	329	&& pc[1] == 0xF8410000 + TOC_SAVE_SLOT)
	330	#endif
	331	)
2374a88a AM	332	{
	333	/* We are in a plt call stub or r2 adjusting long branch stub,
	334	before r2 has been saved. Keep REG_UNSAVED. */
	335	}
2374a88a AM	336	else
	337	{
	338	unsigned int *insn
	339	= (unsigned int *) _Unwind_GetGR (context, R_LR);
b54214fe UW	340	if (insn && *insn == 0xE8410000 + TOC_SAVE_SLOT)
	341	_Unwind_SetGRPtr (context, 2, context->cfa + TOC_SAVE_SLOT);
	342	#if _CALL_ELF != 2
	343	/* ELFv2 does not use this function pointer call sequence. */
bd15e32c	344	else if (pc[0] == 0x4E800421
b54214fe	345	&& pc[1] == 0xE8410000 + TOC_SAVE_SLOT)
bd15e32c AM	346	{
	347	/* We are at the bctrl instruction in a call via function
	348	pointer. gcc always emits the load of the new R2 just
	349	before the bctrl so this is the first and only place
	350	we need to use the stored R2. */
	351	_Unwind_Word sp = _Unwind_GetGR (context, 1);
b54214fe	352	_Unwind_SetGRPtr (context, 2, (void *)(sp + TOC_SAVE_SLOT));
bd15e32c	353	}
b54214fe	354	#endif
2374a88a	355	}
754e45a8 JJ	356	}
	357	#endif
	358	}
b7561b5d RMZ	359
	360	#define MD_BACKCHAIN_FALLBACK ppc_backchain_fallback
	361
	362	struct trace_arg
	363	{
	364	/* Stores the list of addresses. */
	365	void **array;
	366	struct unwind_link *unwind_link;
	367	_Unwind_Word cfa;
	368	/* Number of addresses currently stored. */
	369	int count;
	370	/* Maximum number of addresses. */
	371	int size;
	372	};
	373
	374	/* This is the stack layout we see with every stack frame.
	375	Note that every routine is required by the ABI to lay out the stack
	376	like this.
	377
	378	+----------------+ +-----------------+
	379	%r1 -> \| previous frame--------> \| previous frame--->... --> NULL
	380	\| \| \| \|
	381	\| cr save \| \| cr save \|
	382	\| \| \| \|
	383	\| (unused) \| \| lr save \|
	384	+----------------+ +-----------------+
	385
	386	The CR save is only present on 64-bit ABIs.
	387	*/
	388	struct frame_layout
	389	{
	390	struct frame_layout *backchain;
	391	#ifdef __powerpc64__
	392	long int cr_save;
	393	#endif
	394	void *lr_save;
	395	};
	396
	397
75ef0353 JJ	398	static void
75ef0353 JJ	399	ppc_backchain_fallback (struct _Unwind_Context context, void a)
b7561b5d RMZ	400	{
	401	struct frame_layout *current;
	402	struct trace_arg *arg = a;
	403	int count;
	404
8d71d3a3	405	/* Get the last address computed. */
b7561b5d	406	current = context->cfa;
8d71d3a3 RMZ	407
	408	/* If the trace CFA is not the context CFA the backtrace is done. */
	409	if (arg == NULL \|\| arg->cfa != current)
	410	return;
	411
	412	/* Start with next address. */
b7561b5d RMZ	413	current = current->backchain;
	414
	415	for (count = arg->count; current != NULL; current = current->backchain)
	416	{
	417	arg->array[count] = current->lr_save;
	418
	419	/* Check if the symbol is the signal trampoline and get the interrupted
	420	symbol address from the trampoline saved area. */
	421	context->ra = current->lr_save;
	422	if (current->lr_save && get_regs (context))
	423	{
	424	struct rt_sigframe sigframe = (struct rt_sigframe ) current;
	425	if (count + 1 == arg->size)
	426	break;
	427	arg->array[++count] = (void *) sigframe->uc.rsave.nip;
	428	current = (void *) sigframe->uc.rsave.gpr[1];
	429	}
	430	if (count++ >= arg->size)
	431	break;
	432	}
	433
	434	arg->count = count-1;
	435	}