libgcc/config/rs6000/aix-unwind.h - rust-lang/gcc - Git at Google

 /* DWARF2 EH unwinding support for AIX.
    Copyright (C) 2011-2021 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/>.  */

 /* Useful register numbers.  */

 #define R_LR             65
 #define R_CR2            70
 #define R_XER            76
 #define R_FIRST_ALTIVEC  77
 #define R_VRSAVE        109
 #define R_VSCR          110

 /* 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.  */

 #ifdef __64BIT__
 #define MD_FROB_UPDATE_CONTEXT(CTX, FS)					\
   do {									\
     if ((FS)->regs.reg[2].how == REG_UNSAVED)				\
       {									\
 	unsigned int *insn						\
 	  = (unsigned int *)						\
 	    _Unwind_GetGR ((CTX), R_LR);				\
 	if (*insn == 0xE8410028)					\
 	  _Unwind_SetGRPtr ((CTX), 2, (CTX)->cfa + 40);			\
       }									\
   } while (0)
 #else
 #define MD_FROB_UPDATE_CONTEXT(CTX, FS)					\
   do {									\
     if ((FS)->regs.reg[2].how == REG_UNSAVED)				\
       {									\
 	unsigned int *insn						\
 	  = (unsigned int *)						\
 	    _Unwind_GetGR ((CTX), R_LR);				\
 	if (*insn == 0x80410014)					\
 	  _Unwind_SetGRPtr ((CTX), 2, (CTX)->cfa + 20);			\
       }									\
   } while (0)
 #endif

 /* Now on to MD_FALLBACK_FRAME_STATE_FOR.
    32bit AIX 5.2, 5.3, 6.1, 7.X and
    64bit AIX 6.1, 7.X only at this stage.  */

 #include <stdlib.h>
 #include <stddef.h>
 #include <signal.h>
 #include <sys/machine.h>

 #ifdef __64BIT__

 typedef struct __context64 mstate_t;

 #else

 typedef struct mstsave mstate_t;

 #endif

 #define MD_FALLBACK_FRAME_STATE_FOR ppc_aix_fallback_frame_state

 /* If we are compiling on AIX < 5.3, the VMX related datastructs are not
    defined and we take measures to obtain proper runtime behavior if the
    compiled code happens to run on a later version with VMX enabled.  */

 #ifndef MSR_VMX
 #define MSR_VMX 0x2000000
 #endif

 typedef unsigned int uint;
 typedef struct { uint v[4]; } vreg_t;
 typedef struct {
   vreg_t regs[32];
   uint   pad1 [3];
   uint   vscr;
   uint   vrsave;
   uint   pad2 [3];
 } vstate_t;

 #define EXT_CONTEXT_MARK 0x45435458
 #define EXT_CONTEXT_SIZE 4096
 #define BUMPER_SIZE (EXT_CONTEXT_SIZE - sizeof(vstate_t) - (5 * sizeof(int)))

 typedef struct {
   uint     pad1 [4];
   vstate_t vstate;
   char     bumper [BUMPER_SIZE];
   int      mark;
 } extended_context_t;

 typedef struct {
   char bumper [offsetof (ucontext_t, uc_stack) + sizeof (stack_t)];
   extended_context_t * ectx;
   int mark;
 } vmx_ucontext_t;

 /* Determine whether CONTEXT designates a signal handler, and return the
    associated ucontext_t address if so.  Return NULL otherwise.  */

 static ucontext_t *
 ucontext_for (struct _Unwind_Context *context)
 {
   const unsigned int * ra = context->ra;

   /* AIX 5.2, 5.3, 6.1 and 7.X, threaded or not, share common patterns
      and feature variants depending on the configured kernel (unix_mp
      or unix_64).  */

 #ifdef __64BIT__
   if (*(ra - 5) == 0x4c00012c     /* isync             */
       && *(ra - 4) == 0xe8ec0000  /* ld      r7,0(r12) */
       && *(ra - 3) == 0xe84c0008  /* ld      r2,8(r12) */
       && *(ra - 2) == 0x7ce903a6  /* mtctr   r7        */
       && *(ra - 1) == 0x4e800421  /* bctrl             */
       && *(ra - 0) == 0x7de27b78) /* mr      r2,r15   <-- context->ra */
     {
       /* unix_64 */
       if (*(ra - 6) == 0x7d000164)  /* mtmsrd  r8 */
 	{
 	  /* AIX 6.1, 7.1 and 7.2 */
 	  return (ucontext_t *)(context->cfa + 0x70);
 	}
     }
 #else
   if (*(ra - 5) == 0x4c00012c     /* isync             */
       && *(ra - 4) == 0x80ec0000  /* lwz     r7,0(r12) */
       && *(ra - 3) == 0x804c0004  /* lwz     r2,4(r12) */
       && *(ra - 2) == 0x7ce903a6  /* mtctr   r7        */
       && *(ra - 1) == 0x4e800421  /* bctrl             */
       && *(ra - 0) == 0x7dc37378) /* mr      r3,r14   <-- context->ra */
     {
       /* unix_64 */
       if (*(ra - 6) == 0x7d000164)  /* mtmsrd  r8 */
 	{
 	  switch (*(ra + 18))
 	    {
 	      /* AIX 5.2 */
 	    case 0x835a0520: /* lwz r26,1312(r26) */
 	      return (ucontext_t *)(context->cfa + 0x70);

 	      /* AIX 5.3 */
 	    case 0x835a0570:  /* lwz r26,1392(r26) */
 	      return (ucontext_t *)(context->cfa + 0x40);

 	      /* AIX 6.1 and 7.1 */
 	    case 0x2c1a0000:  /* cmpwi   r26,0 */
 	      return (ucontext_t *)(context->cfa + 0x40);

 	      /* AIX 7.2 */
 	    case 0x3800000a:  /* li   r0,A */
 	      return (ucontext_t *)(context->cfa + 0x40);

 	    default:
 	      return 0;
 	    }
 	}

       /* unix_mp */
       if (*(ra - 6) == 0x7d000124)  /* mtmsr  r8 */
 	{
 	  typedef struct {
 	    char pad[56];
 	    ucontext_t ucontext;
 	    siginfo_t siginfo;
 	  } aix52_stack_t;

 	  aix52_stack_t * frame = (aix52_stack_t *) context->cfa;
 	  return &frame->ucontext;
 	}
     }
 #endif
   return 0;
 }

 /* The fallback proper.  */

 #ifdef __LIBGCC_DWARF_ALT_FRAME_RETURN_COLUMN__
 #define RETURN_COLUMN __LIBGCC_DWARF_ALT_FRAME_RETURN_COLUMN__
 #else
 #define RETURN_COLUMN ARG_POINTER_REGNUM
 #endif

 #define REGISTER_CFA_OFFSET_FOR(FS,REGNO,ADDR,CFA)\
 do { \
 (FS)->regs.reg[REGNO].how = REG_SAVED_OFFSET; \
 (FS)->regs.reg[REGNO].loc.offset = (long) (ADDR) - (CFA); \
 } while (0)

 static _Unwind_Reason_Code
 ppc_aix_fallback_frame_state (struct _Unwind_Context *context,
 			      _Unwind_FrameState *fs)
 {
   ucontext_t * uctx = ucontext_for (context);
   mstate_t * mctx;

   long new_cfa;
   int i;

   if (uctx == NULL)
     return _URC_END_OF_STACK;

   mctx = &uctx->uc_mcontext.jmp_context;

   /* The "kernel" frame cfa is the stack pointer at the signal occurrence
      point.  */
   new_cfa = mctx->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;

   /* And we state how to find the various registers it has saved with
      relative offset rules from there.  */

   for (i = 0; i < 32; i++)
     if (i != __LIBGCC_STACK_POINTER_REGNUM__)
       REGISTER_CFA_OFFSET_FOR (fs, i, &mctx->gpr[i], new_cfa);

   REGISTER_CFA_OFFSET_FOR (fs, R_CR2, &mctx->cr, new_cfa);
   REGISTER_CFA_OFFSET_FOR (fs, R_XER, &mctx->xer, new_cfa);
   REGISTER_CFA_OFFSET_FOR (fs, R_LR, &mctx->lr, new_cfa);

   fs->retaddr_column = RETURN_COLUMN;
   REGISTER_CFA_OFFSET_FOR (fs, RETURN_COLUMN, &mctx->iar, new_cfa);
   fs->signal_frame = 1;

   /* Honor FP Ever Used ...   */
   if (mctx->fpeu)
     {
       for (i = 0; i < 32; i++)
 	REGISTER_CFA_OFFSET_FOR (fs, i+32, &mctx->fpr[i], new_cfa);
     }

   /* Honor VMX context, if any.  We expect the msr bit never to be set in
      environments where there is no VMX support, e.g. on AIX < 5.3.  */
   if (mctx->msr & MSR_VMX)
     {
       vmx_ucontext_t * uc = (vmx_ucontext_t *) uctx;

       if (uc->mark == EXT_CONTEXT_MARK && uc->ectx->mark == EXT_CONTEXT_MARK)
 	{
 	  vstate_t * vstate = &uc->ectx->vstate;

 	  for (i = 0; i < 32; i++)
 	    REGISTER_CFA_OFFSET_FOR
 	    (fs, i+R_FIRST_ALTIVEC, &vstate->regs[i], new_cfa);

 	  REGISTER_CFA_OFFSET_FOR (fs, R_VSCR, &vstate->vscr, new_cfa);
 	  REGISTER_CFA_OFFSET_FOR (fs, R_VRSAVE, &vstate->vrsave, new_cfa);
 	}
     }

   return _URC_NO_REASON;
 }
	/* DWARF2 EH unwinding support for AIX.
	Copyright (C) 2011-2021 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/>. */

	/* Useful register numbers. */

	#define R_LR 65
	#define R_CR2 70
	#define R_XER 76
	#define R_FIRST_ALTIVEC 77
	#define R_VRSAVE 109
	#define R_VSCR 110

	/* 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. */

	#ifdef __64BIT__
	#define MD_FROB_UPDATE_CONTEXT(CTX, FS) \
	do { \
	if ((FS)->regs.reg[2].how == REG_UNSAVED) \
	{ \
	unsigned int *insn \
	= (unsigned int *) \
	_Unwind_GetGR ((CTX), R_LR); \
	if (*insn == 0xE8410028) \
	_Unwind_SetGRPtr ((CTX), 2, (CTX)->cfa + 40); \
	} \
	} while (0)
	#else
	#define MD_FROB_UPDATE_CONTEXT(CTX, FS) \
	do { \
	if ((FS)->regs.reg[2].how == REG_UNSAVED) \
	{ \
	unsigned int *insn \
	= (unsigned int *) \
	_Unwind_GetGR ((CTX), R_LR); \
	if (*insn == 0x80410014) \
	_Unwind_SetGRPtr ((CTX), 2, (CTX)->cfa + 20); \
	} \
	} while (0)
	#endif

	/* Now on to MD_FALLBACK_FRAME_STATE_FOR.
	32bit AIX 5.2, 5.3, 6.1, 7.X and
	64bit AIX 6.1, 7.X only at this stage. */

	#include <stdlib.h>
	#include <stddef.h>
	#include <signal.h>
	#include <sys/machine.h>

	#ifdef __64BIT__

	typedef struct __context64 mstate_t;

	#else

	typedef struct mstsave mstate_t;

	#endif

	#define MD_FALLBACK_FRAME_STATE_FOR ppc_aix_fallback_frame_state

	/* If we are compiling on AIX < 5.3, the VMX related datastructs are not
	defined and we take measures to obtain proper runtime behavior if the
	compiled code happens to run on a later version with VMX enabled. */

	#ifndef MSR_VMX
	#define MSR_VMX 0x2000000
	#endif

	typedef unsigned int uint;
	typedef struct { uint v[4]; } vreg_t;
	typedef struct {
	vreg_t regs[32];
	uint pad1 [3];
	uint vscr;
	uint vrsave;
	uint pad2 [3];
	} vstate_t;

	#define EXT_CONTEXT_MARK 0x45435458
	#define EXT_CONTEXT_SIZE 4096
	#define BUMPER_SIZE (EXT_CONTEXT_SIZE - sizeof(vstate_t) - (5 * sizeof(int)))

	typedef struct {
	uint pad1 [4];
	vstate_t vstate;
	char bumper [BUMPER_SIZE];
	int mark;
	} extended_context_t;

	typedef struct {
	char bumper [offsetof (ucontext_t, uc_stack) + sizeof (stack_t)];
	extended_context_t * ectx;
	int mark;
	} vmx_ucontext_t;

	/* Determine whether CONTEXT designates a signal handler, and return the
	associated ucontext_t address if so. Return NULL otherwise. */

	static ucontext_t *
	ucontext_for (struct _Unwind_Context *context)
	{
	const unsigned int * ra = context->ra;

	/* AIX 5.2, 5.3, 6.1 and 7.X, threaded or not, share common patterns
	and feature variants depending on the configured kernel (unix_mp
	or unix_64). */

	#ifdef __64BIT__
	if ((ra - 5) == 0x4c00012c / isync */
	&& (ra - 4) == 0xe8ec0000 / ld r7,0(r12) */
	&& (ra - 3) == 0xe84c0008 / ld r2,8(r12) */
	&& (ra - 2) == 0x7ce903a6 / mtctr r7 */
	&& (ra - 1) == 0x4e800421 / bctrl */
	&& (ra - 0) == 0x7de27b78) / mr r2,r15 <-- context->ra */
	{
	/* unix_64 */
	if ((ra - 6) == 0x7d000164) / mtmsrd r8 */
	{
	/* AIX 6.1, 7.1 and 7.2 */
	return (ucontext_t *)(context->cfa + 0x70);
	}
	}
	#else
	if ((ra - 5) == 0x4c00012c / isync */
	&& (ra - 4) == 0x80ec0000 / lwz r7,0(r12) */
	&& (ra - 3) == 0x804c0004 / lwz r2,4(r12) */
	&& (ra - 2) == 0x7ce903a6 / mtctr r7 */
	&& (ra - 1) == 0x4e800421 / bctrl */
	&& (ra - 0) == 0x7dc37378) / mr r3,r14 <-- context->ra */
	{
	/* unix_64 */
	if ((ra - 6) == 0x7d000164) / mtmsrd r8 */
	{
	switch (*(ra + 18))
	{
	/* AIX 5.2 */
	case 0x835a0520: /* lwz r26,1312(r26) */
	return (ucontext_t *)(context->cfa + 0x70);

	/* AIX 5.3 */
	case 0x835a0570: /* lwz r26,1392(r26) */
	return (ucontext_t *)(context->cfa + 0x40);

	/* AIX 6.1 and 7.1 */
	case 0x2c1a0000: /* cmpwi r26,0 */
	return (ucontext_t *)(context->cfa + 0x40);

	/* AIX 7.2 */
	case 0x3800000a: /* li r0,A */
	return (ucontext_t *)(context->cfa + 0x40);

	default:
	return 0;
	}
	}

	/* unix_mp */
	if ((ra - 6) == 0x7d000124) / mtmsr r8 */
	{
	typedef struct {
	char pad[56];
	ucontext_t ucontext;
	siginfo_t siginfo;
	} aix52_stack_t;

	aix52_stack_t * frame = (aix52_stack_t *) context->cfa;
	return &frame->ucontext;
	}
	}
	#endif
	return 0;
	}

	/* The fallback proper. */

	#ifdef __LIBGCC_DWARF_ALT_FRAME_RETURN_COLUMN__
	#define RETURN_COLUMN __LIBGCC_DWARF_ALT_FRAME_RETURN_COLUMN__
	#else
	#define RETURN_COLUMN ARG_POINTER_REGNUM
	#endif

	#define REGISTER_CFA_OFFSET_FOR(FS,REGNO,ADDR,CFA)\
	do { \
	(FS)->regs.reg[REGNO].how = REG_SAVED_OFFSET; \
	(FS)->regs.reg[REGNO].loc.offset = (long) (ADDR) - (CFA); \
	} while (0)

	static _Unwind_Reason_Code
	ppc_aix_fallback_frame_state (struct _Unwind_Context *context,
	_Unwind_FrameState *fs)
	{
	ucontext_t * uctx = ucontext_for (context);
	mstate_t * mctx;

	long new_cfa;
	int i;

	if (uctx == NULL)
	return _URC_END_OF_STACK;

	mctx = &uctx->uc_mcontext.jmp_context;

	/* The "kernel" frame cfa is the stack pointer at the signal occurrence
	point. */
	new_cfa = mctx->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;

	/* And we state how to find the various registers it has saved with
	relative offset rules from there. */

	for (i = 0; i < 32; i++)
	if (i != __LIBGCC_STACK_POINTER_REGNUM__)
	REGISTER_CFA_OFFSET_FOR (fs, i, &mctx->gpr[i], new_cfa);

	REGISTER_CFA_OFFSET_FOR (fs, R_CR2, &mctx->cr, new_cfa);
	REGISTER_CFA_OFFSET_FOR (fs, R_XER, &mctx->xer, new_cfa);
	REGISTER_CFA_OFFSET_FOR (fs, R_LR, &mctx->lr, new_cfa);

	fs->retaddr_column = RETURN_COLUMN;
	REGISTER_CFA_OFFSET_FOR (fs, RETURN_COLUMN, &mctx->iar, new_cfa);
	fs->signal_frame = 1;

	/* Honor FP Ever Used ... */
	if (mctx->fpeu)
	{
	for (i = 0; i < 32; i++)
	REGISTER_CFA_OFFSET_FOR (fs, i+32, &mctx->fpr[i], new_cfa);
	}

	/* Honor VMX context, if any. We expect the msr bit never to be set in
	environments where there is no VMX support, e.g. on AIX < 5.3. */
	if (mctx->msr & MSR_VMX)
	{
	vmx_ucontext_t * uc = (vmx_ucontext_t *) uctx;

	if (uc->mark == EXT_CONTEXT_MARK && uc->ectx->mark == EXT_CONTEXT_MARK)
	{
	vstate_t * vstate = &uc->ectx->vstate;

	for (i = 0; i < 32; i++)
	REGISTER_CFA_OFFSET_FOR
	(fs, i+R_FIRST_ALTIVEC, &vstate->regs[i], new_cfa);

	REGISTER_CFA_OFFSET_FOR (fs, R_VSCR, &vstate->vscr, new_cfa);
	REGISTER_CFA_OFFSET_FOR (fs, R_VRSAVE, &vstate->vrsave, new_cfa);
	}
	}

	return _URC_NO_REASON;
	}