387 lines
9.6 KiB
C
387 lines
9.6 KiB
C
/* ARM EABI compliant unwinding routines
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Copyright (C) 2004-2020 Free Software Foundation, Inc.
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Contributed by Paul Brook
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This file is free software; you can redistribute it and/or modify it
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under the terms of the GNU General Public License as published by the
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Free Software Foundation; either version 3, or (at your option) any
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later version.
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This file is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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General Public License for more details.
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Under Section 7 of GPL version 3, you are granted additional
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permissions described in the GCC Runtime Library Exception, version
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3.1, as published by the Free Software Foundation.
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You should have received a copy of the GNU General Public License and
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a copy of the GCC Runtime Library Exception along with this program;
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see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
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<http://www.gnu.org/licenses/>. */
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#pragma GCC target ("general-regs-only")
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#include "unwind.h"
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/* We add a prototype for abort here to avoid creating a dependency on
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target headers. */
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extern void abort (void);
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typedef struct _ZSt9type_info type_info; /* This names C++ type_info type */
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/* Misc constants. */
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#define R_IP 12
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#define R_SP 13
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#define R_LR 14
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#define R_PC 15
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#define uint32_highbit (((_uw) 1) << 31)
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void __attribute__((weak)) __cxa_call_unexpected(_Unwind_Control_Block *ucbp);
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/* Unwind descriptors. */
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typedef struct
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{
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_uw16 length;
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_uw16 offset;
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} EHT16;
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typedef struct
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{
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_uw length;
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_uw offset;
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} EHT32;
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/* Calculate the address encoded by a 31-bit self-relative offset at address
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P. Copy of routine in unwind-arm.c. */
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static inline _uw
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selfrel_offset31 (const _uw *p)
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{
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_uw offset;
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offset = *p;
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/* Sign extend to 32 bits. */
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if (offset & (1 << 30))
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offset |= 1u << 31;
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return offset + (_uw) p;
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}
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/* Personality routine helper functions. */
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#define CODE_FINISH (0xb0)
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/* Return the next byte of unwinding information, or CODE_FINISH if there is
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no data remaining. */
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static inline _uw8
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next_unwind_byte (__gnu_unwind_state * uws)
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{
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_uw8 b;
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if (uws->bytes_left == 0)
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{
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/* Load another word */
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if (uws->words_left == 0)
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return CODE_FINISH; /* Nothing left. */
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uws->words_left--;
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uws->data = *(uws->next++);
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uws->bytes_left = 3;
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}
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else
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uws->bytes_left--;
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/* Extract the most significant byte. */
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b = (uws->data >> 24) & 0xff;
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uws->data <<= 8;
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return b;
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}
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/* Execute the unwinding instructions described by UWS. */
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_Unwind_Reason_Code
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__gnu_unwind_execute (_Unwind_Context * context, __gnu_unwind_state * uws)
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{
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_uw op;
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int set_pc;
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_uw reg;
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set_pc = 0;
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for (;;)
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{
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op = next_unwind_byte (uws);
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if (op == CODE_FINISH)
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{
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/* If we haven't already set pc then copy it from lr. */
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if (!set_pc)
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{
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_Unwind_VRS_Get (context, _UVRSC_CORE, R_LR, _UVRSD_UINT32,
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®);
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_Unwind_VRS_Set (context, _UVRSC_CORE, R_PC, _UVRSD_UINT32,
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®);
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set_pc = 1;
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}
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/* Drop out of the loop. */
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break;
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}
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if ((op & 0x80) == 0)
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{
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/* vsp = vsp +- (imm6 << 2 + 4). */
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_uw offset;
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offset = ((op & 0x3f) << 2) + 4;
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_Unwind_VRS_Get (context, _UVRSC_CORE, R_SP, _UVRSD_UINT32, ®);
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if (op & 0x40)
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reg -= offset;
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else
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reg += offset;
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_Unwind_VRS_Set (context, _UVRSC_CORE, R_SP, _UVRSD_UINT32, ®);
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continue;
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}
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if ((op & 0xf0) == 0x80)
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{
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op = (op << 8) | next_unwind_byte (uws);
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if (op == 0x8000)
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{
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/* Refuse to unwind. */
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return _URC_FAILURE;
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}
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/* Pop r4-r15 under mask. */
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op = (op << 4) & 0xfff0;
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if (_Unwind_VRS_Pop (context, _UVRSC_CORE, op, _UVRSD_UINT32)
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!= _UVRSR_OK)
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return _URC_FAILURE;
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if (op & (1 << R_PC))
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set_pc = 1;
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continue;
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}
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if ((op & 0xf0) == 0x90)
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{
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op &= 0xf;
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if (op == 13 || op == 15)
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/* Reserved. */
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return _URC_FAILURE;
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/* vsp = r[nnnn]. */
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_Unwind_VRS_Get (context, _UVRSC_CORE, op, _UVRSD_UINT32, ®);
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_Unwind_VRS_Set (context, _UVRSC_CORE, R_SP, _UVRSD_UINT32, ®);
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continue;
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}
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if ((op & 0xf0) == 0xa0)
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{
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/* Pop r4-r[4+nnn], [lr]. */
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_uw mask;
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mask = (0xff0 >> (7 - (op & 7))) & 0xff0;
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if (op & 8)
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mask |= (1 << R_LR);
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if (_Unwind_VRS_Pop (context, _UVRSC_CORE, mask, _UVRSD_UINT32)
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!= _UVRSR_OK)
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return _URC_FAILURE;
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continue;
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}
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if ((op & 0xf0) == 0xb0)
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{
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/* op == 0xb0 already handled. */
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if (op == 0xb1)
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{
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op = next_unwind_byte (uws);
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if (op == 0 || ((op & 0xf0) != 0))
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/* Spare. */
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return _URC_FAILURE;
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/* Pop r0-r4 under mask. */
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if (_Unwind_VRS_Pop (context, _UVRSC_CORE, op, _UVRSD_UINT32)
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!= _UVRSR_OK)
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return _URC_FAILURE;
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continue;
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}
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if (op == 0xb2)
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{
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/* vsp = vsp + 0x204 + (uleb128 << 2). */
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int shift;
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_Unwind_VRS_Get (context, _UVRSC_CORE, R_SP, _UVRSD_UINT32,
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®);
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op = next_unwind_byte (uws);
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shift = 2;
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while (op & 0x80)
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{
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reg += ((op & 0x7f) << shift);
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shift += 7;
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op = next_unwind_byte (uws);
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}
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reg += ((op & 0x7f) << shift) + 0x204;
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_Unwind_VRS_Set (context, _UVRSC_CORE, R_SP, _UVRSD_UINT32,
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®);
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continue;
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}
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if (op == 0xb3)
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{
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/* Pop VFP registers with fldmx. */
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op = next_unwind_byte (uws);
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op = ((op & 0xf0) << 12) | ((op & 0xf) + 1);
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if (_Unwind_VRS_Pop (context, _UVRSC_VFP, op, _UVRSD_VFPX)
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!= _UVRSR_OK)
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return _URC_FAILURE;
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continue;
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}
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if ((op & 0xfc) == 0xb4) /* Obsolete FPA. */
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return _URC_FAILURE;
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/* op & 0xf8 == 0xb8. */
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/* Pop VFP D[8]-D[8+nnn] with fldmx. */
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op = 0x80000 | ((op & 7) + 1);
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if (_Unwind_VRS_Pop (context, _UVRSC_VFP, op, _UVRSD_VFPX)
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!= _UVRSR_OK)
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return _URC_FAILURE;
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continue;
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}
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if ((op & 0xf0) == 0xc0)
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{
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if (op == 0xc6)
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{
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/* Pop iWMMXt D registers. */
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op = next_unwind_byte (uws);
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op = ((op & 0xf0) << 12) | ((op & 0xf) + 1);
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if (_Unwind_VRS_Pop (context, _UVRSC_WMMXD, op, _UVRSD_UINT64)
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!= _UVRSR_OK)
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return _URC_FAILURE;
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continue;
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}
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if (op == 0xc7)
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{
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op = next_unwind_byte (uws);
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if (op == 0 || (op & 0xf0) != 0)
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/* Spare. */
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return _URC_FAILURE;
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/* Pop iWMMXt wCGR{3,2,1,0} under mask. */
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if (_Unwind_VRS_Pop (context, _UVRSC_WMMXC, op, _UVRSD_UINT32)
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!= _UVRSR_OK)
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return _URC_FAILURE;
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continue;
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}
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if ((op & 0xf8) == 0xc0)
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{
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/* Pop iWMMXt wR[10]-wR[10+nnn]. */
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op = 0xa0000 | ((op & 0xf) + 1);
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if (_Unwind_VRS_Pop (context, _UVRSC_WMMXD, op, _UVRSD_UINT64)
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!= _UVRSR_OK)
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return _URC_FAILURE;
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continue;
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}
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if (op == 0xc8)
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{
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/* Pop VFPv3 registers D[16+ssss]-D[16+ssss+cccc] with vldm. */
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op = next_unwind_byte (uws);
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op = (((op & 0xf0) + 16) << 12) | ((op & 0xf) + 1);
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if (_Unwind_VRS_Pop (context, _UVRSC_VFP, op, _UVRSD_DOUBLE)
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!= _UVRSR_OK)
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return _URC_FAILURE;
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continue;
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}
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if (op == 0xc9)
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{
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/* Pop VFP registers with fldmd. */
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op = next_unwind_byte (uws);
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op = ((op & 0xf0) << 12) | ((op & 0xf) + 1);
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if (_Unwind_VRS_Pop (context, _UVRSC_VFP, op, _UVRSD_DOUBLE)
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!= _UVRSR_OK)
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return _URC_FAILURE;
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continue;
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}
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/* Spare. */
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return _URC_FAILURE;
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}
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if ((op & 0xf8) == 0xd0)
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{
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/* Pop VFP D[8]-D[8+nnn] with fldmd. */
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op = 0x80000 | ((op & 7) + 1);
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if (_Unwind_VRS_Pop (context, _UVRSC_VFP, op, _UVRSD_DOUBLE)
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!= _UVRSR_OK)
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return _URC_FAILURE;
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continue;
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}
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/* Spare. */
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return _URC_FAILURE;
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}
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return _URC_OK;
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}
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/* Execute the unwinding instructions associated with a frame. UCBP and
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CONTEXT are the current exception object and virtual CPU state
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respectively. */
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_Unwind_Reason_Code
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__gnu_unwind_frame (_Unwind_Control_Block * ucbp, _Unwind_Context * context)
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{
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_uw *ptr;
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__gnu_unwind_state uws;
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ptr = (_uw *) ucbp->pr_cache.ehtp;
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/* Skip over the personality routine address. */
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ptr++;
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/* Setup the unwinder state. */
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uws.data = (*ptr) << 8;
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uws.next = ptr + 1;
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uws.bytes_left = 3;
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uws.words_left = ((*ptr) >> 24) & 0xff;
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return __gnu_unwind_execute (context, &uws);
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}
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/* Get the _Unwind_Control_Block from an _Unwind_Context. */
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static inline _Unwind_Control_Block *
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unwind_UCB_from_context (_Unwind_Context * context)
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{
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return (_Unwind_Control_Block *) _Unwind_GetGR (context, R_IP);
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}
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/* Get the start address of the function being unwound. */
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_Unwind_Ptr
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_Unwind_GetRegionStart (_Unwind_Context * context)
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{
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_Unwind_Control_Block *ucbp;
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ucbp = unwind_UCB_from_context (context);
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return (_Unwind_Ptr) ucbp->pr_cache.fnstart;
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}
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/* Find the Language specific exception data. */
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void *
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_Unwind_GetLanguageSpecificData (_Unwind_Context * context)
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{
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_Unwind_Control_Block *ucbp;
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_uw *ptr;
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/* Get a pointer to the exception table entry. */
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ucbp = unwind_UCB_from_context (context);
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ptr = (_uw *) ucbp->pr_cache.ehtp;
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/* Skip the personality routine address. */
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ptr++;
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/* Skip the unwind opcodes. */
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ptr += (((*ptr) >> 24) & 0xff) + 1;
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return ptr;
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}
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/* These two should never be used. */
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_Unwind_Ptr
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_Unwind_GetDataRelBase (_Unwind_Context *context __attribute__ ((unused)))
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{
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abort ();
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}
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_Unwind_Ptr
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_Unwind_GetTextRelBase (_Unwind_Context *context __attribute__ ((unused)))
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{
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abort ();
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}
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