| /* DWARF2 exception handling and frame unwind runtime interface routines. |
| Copyright (C) 1997-2021 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/>. */ |
| |
| #include "tconfig.h" |
| #include "tsystem.h" |
| #include "coretypes.h" |
| #include "tm.h" |
| #include "libgcc_tm.h" |
| #include "dwarf2.h" |
| #include "unwind.h" |
| #ifdef __USING_SJLJ_EXCEPTIONS__ |
| # define NO_SIZE_OF_ENCODED_VALUE |
| #endif |
| #include "unwind-pe.h" |
| #include "unwind-dw2-fde.h" |
| #include "gthr.h" |
| #include "unwind-dw2.h" |
| |
| #ifdef HAVE_SYS_SDT_H |
| #include <sys/sdt.h> |
| #endif |
| |
| #ifndef __USING_SJLJ_EXCEPTIONS__ |
| |
| #ifndef __LIBGCC_STACK_GROWS_DOWNWARD__ |
| #define __LIBGCC_STACK_GROWS_DOWNWARD__ 0 |
| #else |
| #undef __LIBGCC_STACK_GROWS_DOWNWARD__ |
| #define __LIBGCC_STACK_GROWS_DOWNWARD__ 1 |
| #endif |
| |
| /* Dwarf frame registers used for pre gcc 3.0 compiled glibc. */ |
| #ifndef PRE_GCC3_DWARF_FRAME_REGISTERS |
| #define PRE_GCC3_DWARF_FRAME_REGISTERS __LIBGCC_DWARF_FRAME_REGISTERS__ |
| #endif |
| |
| /* ??? For the public function interfaces, we tend to gcc_assert that the |
| column numbers are in range. For the dwarf2 unwind info this does happen, |
| although so far in a case that doesn't actually matter. |
| |
| See PR49146, in which a call from x86_64 ms abi to x86_64 unix abi stores |
| the call-saved xmm registers and annotates them. We havn't bothered |
| providing support for the xmm registers for the x86_64 port primarily |
| because the 64-bit windows targets don't use dwarf2 unwind, using sjlj or |
| SEH instead. Adding the support for unix targets would generally be a |
| waste. However, some runtime libraries supplied with ICC do contain such |
| an unorthodox transition, as well as the unwind info to match. This loss |
| of register restoration doesn't matter in practice, because the exception |
| is caught in the native unix abi, where all of the xmm registers are |
| call clobbered. |
| |
| Ideally, we'd record some bit to notice when we're failing to restore some |
| register recorded in the unwind info, but to do that we need annotation on |
| the unix->ms abi edge, so that we know when the register data may be |
| discarded. And since this edge is also within the ICC library, we're |
| unlikely to be able to get the new annotation. |
| |
| Barring a magic solution to restore the ms abi defined 128-bit xmm registers |
| (as distictly opposed to the full runtime width) without causing extra |
| overhead for normal unix abis, the best solution seems to be to simply |
| ignore unwind data for unknown columns. */ |
| |
| #define UNWIND_COLUMN_IN_RANGE(x) \ |
| __builtin_expect((x) <= __LIBGCC_DWARF_FRAME_REGISTERS__, 1) |
| |
| #ifdef REG_VALUE_IN_UNWIND_CONTEXT |
| typedef _Unwind_Word _Unwind_Context_Reg_Val; |
| |
| #ifndef ASSUME_EXTENDED_UNWIND_CONTEXT |
| #define ASSUME_EXTENDED_UNWIND_CONTEXT 1 |
| #endif |
| |
| static inline _Unwind_Word |
| _Unwind_Get_Unwind_Word (_Unwind_Context_Reg_Val val) |
| { |
| return val; |
| } |
| |
| static inline _Unwind_Context_Reg_Val |
| _Unwind_Get_Unwind_Context_Reg_Val (_Unwind_Word val) |
| { |
| return val; |
| } |
| #else |
| typedef void *_Unwind_Context_Reg_Val; |
| |
| static inline _Unwind_Word |
| _Unwind_Get_Unwind_Word (_Unwind_Context_Reg_Val val) |
| { |
| return (_Unwind_Word) (_Unwind_Internal_Ptr) val; |
| } |
| |
| static inline _Unwind_Context_Reg_Val |
| _Unwind_Get_Unwind_Context_Reg_Val (_Unwind_Word val) |
| { |
| return (_Unwind_Context_Reg_Val) (_Unwind_Internal_Ptr) val; |
| } |
| #endif |
| |
| #ifndef ASSUME_EXTENDED_UNWIND_CONTEXT |
| #define ASSUME_EXTENDED_UNWIND_CONTEXT 0 |
| #endif |
| |
| /* This is the register and unwind state for a particular frame. This |
| provides the information necessary to unwind up past a frame and return |
| to its caller. */ |
| struct _Unwind_Context |
| { |
| _Unwind_Context_Reg_Val reg[__LIBGCC_DWARF_FRAME_REGISTERS__+1]; |
| void *cfa; |
| void *ra; |
| void *lsda; |
| struct dwarf_eh_bases bases; |
| /* Signal frame context. */ |
| #define SIGNAL_FRAME_BIT ((~(_Unwind_Word) 0 >> 1) + 1) |
| /* Context which has version/args_size/by_value fields. */ |
| #define EXTENDED_CONTEXT_BIT ((~(_Unwind_Word) 0 >> 2) + 1) |
| /* Bit reserved on AArch64, return address has been signed with A or B |
| key. */ |
| #define RA_SIGNED_BIT ((~(_Unwind_Word) 0 >> 3) + 1) |
| _Unwind_Word flags; |
| /* 0 for now, can be increased when further fields are added to |
| struct _Unwind_Context. */ |
| _Unwind_Word version; |
| _Unwind_Word args_size; |
| char by_value[__LIBGCC_DWARF_FRAME_REGISTERS__+1]; |
| }; |
| |
| /* Byte size of every register managed by these routines. */ |
| static unsigned char dwarf_reg_size_table[__LIBGCC_DWARF_FRAME_REGISTERS__+1]; |
| |
| |
| /* Read unaligned data from the instruction buffer. */ |
| |
| union unaligned |
| { |
| void *p; |
| unsigned u2 __attribute__ ((mode (HI))); |
| unsigned u4 __attribute__ ((mode (SI))); |
| unsigned u8 __attribute__ ((mode (DI))); |
| signed s2 __attribute__ ((mode (HI))); |
| signed s4 __attribute__ ((mode (SI))); |
| signed s8 __attribute__ ((mode (DI))); |
| } __attribute__ ((packed)); |
| |
| static void uw_update_context (struct _Unwind_Context *, _Unwind_FrameState *); |
| static _Unwind_Reason_Code uw_frame_state_for (struct _Unwind_Context *, |
| _Unwind_FrameState *); |
| |
| static inline void * |
| read_pointer (const void *p) { const union unaligned *up = p; return up->p; } |
| |
| static inline int |
| read_1u (const void *p) { return *(const unsigned char *) p; } |
| |
| static inline int |
| read_1s (const void *p) { return *(const signed char *) p; } |
| |
| static inline int |
| read_2u (const void *p) { const union unaligned *up = p; return up->u2; } |
| |
| static inline int |
| read_2s (const void *p) { const union unaligned *up = p; return up->s2; } |
| |
| static inline unsigned int |
| read_4u (const void *p) { const union unaligned *up = p; return up->u4; } |
| |
| static inline int |
| read_4s (const void *p) { const union unaligned *up = p; return up->s4; } |
| |
| static inline unsigned long |
| read_8u (const void *p) { const union unaligned *up = p; return up->u8; } |
| |
| static inline unsigned long |
| read_8s (const void *p) { const union unaligned *up = p; return up->s8; } |
| |
| static inline _Unwind_Word |
| _Unwind_IsSignalFrame (struct _Unwind_Context *context) |
| { |
| return (context->flags & SIGNAL_FRAME_BIT) ? 1 : 0; |
| } |
| |
| static inline void |
| _Unwind_SetSignalFrame (struct _Unwind_Context *context, int val) |
| { |
| if (val) |
| context->flags |= SIGNAL_FRAME_BIT; |
| else |
| context->flags &= ~SIGNAL_FRAME_BIT; |
| } |
| |
| static inline _Unwind_Word |
| _Unwind_IsExtendedContext (struct _Unwind_Context *context) |
| { |
| return (ASSUME_EXTENDED_UNWIND_CONTEXT |
| || (context->flags & EXTENDED_CONTEXT_BIT)); |
| } |
| |
| /* Get the value of register REGNO as saved in CONTEXT. */ |
| |
| inline _Unwind_Word |
| _Unwind_GetGR (struct _Unwind_Context *context, int regno) |
| { |
| int size, index; |
| _Unwind_Context_Reg_Val val; |
| |
| #ifdef DWARF_ZERO_REG |
| if (regno == DWARF_ZERO_REG) |
| return 0; |
| #endif |
| |
| index = DWARF_REG_TO_UNWIND_COLUMN (regno); |
| gcc_assert (index < (int) sizeof(dwarf_reg_size_table)); |
| size = dwarf_reg_size_table[index]; |
| val = context->reg[index]; |
| |
| if (_Unwind_IsExtendedContext (context) && context->by_value[index]) |
| return _Unwind_Get_Unwind_Word (val); |
| |
| #ifdef DWARF_LAZY_REGISTER_VALUE |
| { |
| _Unwind_Word value; |
| if (DWARF_LAZY_REGISTER_VALUE (regno, &value)) |
| return value; |
| } |
| #endif |
| |
| /* This will segfault if the register hasn't been saved. */ |
| if (size == sizeof(_Unwind_Ptr)) |
| return * (_Unwind_Ptr *) (_Unwind_Internal_Ptr) val; |
| else |
| { |
| gcc_assert (size == sizeof(_Unwind_Word)); |
| return * (_Unwind_Word *) (_Unwind_Internal_Ptr) val; |
| } |
| } |
| |
| static inline void * |
| _Unwind_GetPtr (struct _Unwind_Context *context, int index) |
| { |
| return (void *)(_Unwind_Ptr) _Unwind_GetGR (context, index); |
| } |
| |
| /* Get the value of the CFA as saved in CONTEXT. */ |
| |
| _Unwind_Word |
| _Unwind_GetCFA (struct _Unwind_Context *context) |
| { |
| return (_Unwind_Ptr) context->cfa; |
| } |
| |
| /* Overwrite the saved value for register INDEX in CONTEXT with VAL. */ |
| |
| inline void |
| _Unwind_SetGR (struct _Unwind_Context *context, int index, _Unwind_Word val) |
| { |
| int size; |
| void *ptr; |
| |
| index = DWARF_REG_TO_UNWIND_COLUMN (index); |
| gcc_assert (index < (int) sizeof(dwarf_reg_size_table)); |
| size = dwarf_reg_size_table[index]; |
| |
| if (_Unwind_IsExtendedContext (context) && context->by_value[index]) |
| { |
| context->reg[index] = _Unwind_Get_Unwind_Context_Reg_Val (val); |
| return; |
| } |
| |
| ptr = (void *) (_Unwind_Internal_Ptr) context->reg[index]; |
| |
| if (size == sizeof(_Unwind_Ptr)) |
| * (_Unwind_Ptr *) ptr = val; |
| else |
| { |
| gcc_assert (size == sizeof(_Unwind_Word)); |
| * (_Unwind_Word *) ptr = val; |
| } |
| } |
| |
| /* Get the pointer to a register INDEX as saved in CONTEXT. */ |
| |
| static inline void * |
| _Unwind_GetGRPtr (struct _Unwind_Context *context, int index) |
| { |
| index = DWARF_REG_TO_UNWIND_COLUMN (index); |
| if (_Unwind_IsExtendedContext (context) && context->by_value[index]) |
| return &context->reg[index]; |
| return (void *) (_Unwind_Internal_Ptr) context->reg[index]; |
| } |
| |
| /* Set the pointer to a register INDEX as saved in CONTEXT. */ |
| |
| static inline void |
| _Unwind_SetGRPtr (struct _Unwind_Context *context, int index, void *p) |
| { |
| index = DWARF_REG_TO_UNWIND_COLUMN (index); |
| if (_Unwind_IsExtendedContext (context)) |
| context->by_value[index] = 0; |
| context->reg[index] = (_Unwind_Context_Reg_Val) (_Unwind_Internal_Ptr) p; |
| } |
| |
| /* Overwrite the saved value for register INDEX in CONTEXT with VAL. */ |
| |
| static inline void |
| _Unwind_SetGRValue (struct _Unwind_Context *context, int index, |
| _Unwind_Word val) |
| { |
| index = DWARF_REG_TO_UNWIND_COLUMN (index); |
| gcc_assert (index < (int) sizeof(dwarf_reg_size_table)); |
| /* Return column size may be smaller than _Unwind_Context_Reg_Val. */ |
| gcc_assert (dwarf_reg_size_table[index] <= sizeof (_Unwind_Context_Reg_Val)); |
| |
| context->by_value[index] = 1; |
| context->reg[index] = _Unwind_Get_Unwind_Context_Reg_Val (val); |
| } |
| |
| /* Return nonzero if register INDEX is stored by value rather than |
| by reference. */ |
| |
| static inline int |
| _Unwind_GRByValue (struct _Unwind_Context *context, int index) |
| { |
| index = DWARF_REG_TO_UNWIND_COLUMN (index); |
| return context->by_value[index]; |
| } |
| |
| /* Retrieve the return address for CONTEXT. */ |
| |
| inline _Unwind_Ptr |
| _Unwind_GetIP (struct _Unwind_Context *context) |
| { |
| return (_Unwind_Ptr) context->ra; |
| } |
| |
| /* Retrieve the return address and flag whether that IP is before |
| or after first not yet fully executed instruction. */ |
| |
| inline _Unwind_Ptr |
| _Unwind_GetIPInfo (struct _Unwind_Context *context, int *ip_before_insn) |
| { |
| *ip_before_insn = _Unwind_IsSignalFrame (context); |
| return (_Unwind_Ptr) context->ra; |
| } |
| |
| /* Overwrite the return address for CONTEXT with VAL. */ |
| |
| inline void |
| _Unwind_SetIP (struct _Unwind_Context *context, _Unwind_Ptr val) |
| { |
| context->ra = (void *) val; |
| } |
| |
| void * |
| _Unwind_GetLanguageSpecificData (struct _Unwind_Context *context) |
| { |
| return context->lsda; |
| } |
| |
| _Unwind_Ptr |
| _Unwind_GetRegionStart (struct _Unwind_Context *context) |
| { |
| return (_Unwind_Ptr) context->bases.func; |
| } |
| |
| void * |
| _Unwind_FindEnclosingFunction (void *pc) |
| { |
| struct dwarf_eh_bases bases; |
| const struct dwarf_fde *fde = _Unwind_Find_FDE (pc-1, &bases); |
| if (fde) |
| return bases.func; |
| else |
| return NULL; |
| } |
| |
| #ifndef __ia64__ |
| _Unwind_Ptr |
| _Unwind_GetDataRelBase (struct _Unwind_Context *context) |
| { |
| return (_Unwind_Ptr) context->bases.dbase; |
| } |
| |
| _Unwind_Ptr |
| _Unwind_GetTextRelBase (struct _Unwind_Context *context) |
| { |
| return (_Unwind_Ptr) context->bases.tbase; |
| } |
| #endif |
| |
| #include "md-unwind-support.h" |
| |
| /* Extract any interesting information from the CIE for the translation |
| unit F belongs to. Return a pointer to the byte after the augmentation, |
| or NULL if we encountered an undecipherable augmentation. */ |
| |
| static const unsigned char * |
| extract_cie_info (const struct dwarf_cie *cie, struct _Unwind_Context *context, |
| _Unwind_FrameState *fs) |
| { |
| const unsigned char *aug = cie->augmentation; |
| const unsigned char *p = aug + strlen ((const char *)aug) + 1; |
| const unsigned char *ret = NULL; |
| _uleb128_t utmp; |
| _sleb128_t stmp; |
| |
| /* g++ v2 "eh" has pointer immediately following augmentation string, |
| so it must be handled first. */ |
| if (aug[0] == 'e' && aug[1] == 'h') |
| { |
| fs->eh_ptr = read_pointer (p); |
| p += sizeof (void *); |
| aug += 2; |
| } |
| |
| /* After the augmentation resp. pointer for "eh" augmentation |
| follows for CIE version >= 4 address size byte and |
| segment size byte. */ |
| if (__builtin_expect (cie->version >= 4, 0)) |
| { |
| if (p[0] != sizeof (void *) || p[1] != 0) |
| return NULL; |
| p += 2; |
| } |
| /* Immediately following this are the code and |
| data alignment and return address column. */ |
| p = read_uleb128 (p, &utmp); |
| fs->code_align = (_Unwind_Word)utmp; |
| p = read_sleb128 (p, &stmp); |
| fs->data_align = (_Unwind_Sword)stmp; |
| if (cie->version == 1) |
| fs->retaddr_column = *p++; |
| else |
| { |
| p = read_uleb128 (p, &utmp); |
| fs->retaddr_column = (_Unwind_Word)utmp; |
| } |
| fs->lsda_encoding = DW_EH_PE_omit; |
| |
| /* If the augmentation starts with 'z', then a uleb128 immediately |
| follows containing the length of the augmentation field following |
| the size. */ |
| if (*aug == 'z') |
| { |
| p = read_uleb128 (p, &utmp); |
| ret = p + utmp; |
| |
| fs->saw_z = 1; |
| ++aug; |
| } |
| |
| /* Iterate over recognized augmentation subsequences. */ |
| while (*aug != '\0') |
| { |
| /* "L" indicates a byte showing how the LSDA pointer is encoded. */ |
| if (aug[0] == 'L') |
| { |
| fs->lsda_encoding = *p++; |
| aug += 1; |
| } |
| |
| /* "R" indicates a byte indicating how FDE addresses are encoded. */ |
| else if (aug[0] == 'R') |
| { |
| fs->fde_encoding = *p++; |
| aug += 1; |
| } |
| |
| /* "P" indicates a personality routine in the CIE augmentation. */ |
| else if (aug[0] == 'P') |
| { |
| _Unwind_Ptr personality; |
| |
| p = read_encoded_value (context, *p, p + 1, &personality); |
| fs->personality = (_Unwind_Personality_Fn) personality; |
| aug += 1; |
| } |
| |
| /* "S" indicates a signal frame. */ |
| else if (aug[0] == 'S') |
| { |
| fs->signal_frame = 1; |
| aug += 1; |
| } |
| /* aarch64 B-key pointer authentication. */ |
| else if (aug[0] == 'B') |
| { |
| aug += 1; |
| } |
| |
| /* Otherwise we have an unknown augmentation string. |
| Bail unless we saw a 'z' prefix. */ |
| else |
| return ret; |
| } |
| |
| return ret ? ret : p; |
| } |
| |
| |
| /* Decode a DW_OP stack program. Return the top of stack. Push INITIAL |
| onto the stack to start. */ |
| |
| static _Unwind_Word |
| execute_stack_op (const unsigned char *op_ptr, const unsigned char *op_end, |
| struct _Unwind_Context *context, _Unwind_Word initial) |
| { |
| _Unwind_Word stack[64]; /* ??? Assume this is enough. */ |
| int stack_elt; |
| |
| stack[0] = initial; |
| stack_elt = 1; |
| |
| while (op_ptr < op_end) |
| { |
| enum dwarf_location_atom op = *op_ptr++; |
| _Unwind_Word result; |
| _uleb128_t reg, utmp; |
| _sleb128_t offset, stmp; |
| |
| switch (op) |
| { |
| case DW_OP_lit0: |
| case DW_OP_lit1: |
| case DW_OP_lit2: |
| case DW_OP_lit3: |
| case DW_OP_lit4: |
| case DW_OP_lit5: |
| case DW_OP_lit6: |
| case DW_OP_lit7: |
| case DW_OP_lit8: |
| case DW_OP_lit9: |
| case DW_OP_lit10: |
| case DW_OP_lit11: |
| case DW_OP_lit12: |
| case DW_OP_lit13: |
| case DW_OP_lit14: |
| case DW_OP_lit15: |
| case DW_OP_lit16: |
| case DW_OP_lit17: |
| case DW_OP_lit18: |
| case DW_OP_lit19: |
| case DW_OP_lit20: |
| case DW_OP_lit21: |
| case DW_OP_lit22: |
| case DW_OP_lit23: |
| case DW_OP_lit24: |
| case DW_OP_lit25: |
| case DW_OP_lit26: |
| case DW_OP_lit27: |
| case DW_OP_lit28: |
| case DW_OP_lit29: |
| case DW_OP_lit30: |
| case DW_OP_lit31: |
| result = op - DW_OP_lit0; |
| break; |
| |
| case DW_OP_addr: |
| result = (_Unwind_Word) (_Unwind_Ptr) read_pointer (op_ptr); |
| op_ptr += sizeof (void *); |
| break; |
| |
| case DW_OP_GNU_encoded_addr: |
| { |
| _Unwind_Ptr presult; |
| op_ptr = read_encoded_value (context, *op_ptr, op_ptr+1, &presult); |
| result = presult; |
| } |
| break; |
| |
| case DW_OP_const1u: |
| result = read_1u (op_ptr); |
| op_ptr += 1; |
| break; |
| case DW_OP_const1s: |
| result = read_1s (op_ptr); |
| op_ptr += 1; |
| break; |
| case DW_OP_const2u: |
| result = read_2u (op_ptr); |
| op_ptr += 2; |
| break; |
| case DW_OP_const2s: |
| result = read_2s (op_ptr); |
| op_ptr += 2; |
| break; |
| case DW_OP_const4u: |
| result = read_4u (op_ptr); |
| op_ptr += 4; |
| break; |
| case DW_OP_const4s: |
| result = read_4s (op_ptr); |
| op_ptr += 4; |
| break; |
| case DW_OP_const8u: |
| result = read_8u (op_ptr); |
| op_ptr += 8; |
| break; |
| case DW_OP_const8s: |
| result = read_8s (op_ptr); |
| op_ptr += 8; |
| break; |
| case DW_OP_constu: |
| op_ptr = read_uleb128 (op_ptr, &utmp); |
| result = (_Unwind_Word)utmp; |
| break; |
| case DW_OP_consts: |
| op_ptr = read_sleb128 (op_ptr, &stmp); |
| result = (_Unwind_Sword)stmp; |
| break; |
| |
| case DW_OP_reg0: |
| case DW_OP_reg1: |
| case DW_OP_reg2: |
| case DW_OP_reg3: |
| case DW_OP_reg4: |
| case DW_OP_reg5: |
| case DW_OP_reg6: |
| case DW_OP_reg7: |
| case DW_OP_reg8: |
| case DW_OP_reg9: |
| case DW_OP_reg10: |
| case DW_OP_reg11: |
| case DW_OP_reg12: |
| case DW_OP_reg13: |
| case DW_OP_reg14: |
| case DW_OP_reg15: |
| case DW_OP_reg16: |
| case DW_OP_reg17: |
| case DW_OP_reg18: |
| case DW_OP_reg19: |
| case DW_OP_reg20: |
| case DW_OP_reg21: |
| case DW_OP_reg22: |
| case DW_OP_reg23: |
| case DW_OP_reg24: |
| case DW_OP_reg25: |
| case DW_OP_reg26: |
| case DW_OP_reg27: |
| case DW_OP_reg28: |
| case DW_OP_reg29: |
| case DW_OP_reg30: |
| case DW_OP_reg31: |
| result = _Unwind_GetGR (context, op - DW_OP_reg0); |
| break; |
| case DW_OP_regx: |
| op_ptr = read_uleb128 (op_ptr, ®); |
| result = _Unwind_GetGR (context, reg); |
| break; |
| |
| case DW_OP_breg0: |
| case DW_OP_breg1: |
| case DW_OP_breg2: |
| case DW_OP_breg3: |
| case DW_OP_breg4: |
| case DW_OP_breg5: |
| case DW_OP_breg6: |
| case DW_OP_breg7: |
| case DW_OP_breg8: |
| case DW_OP_breg9: |
| case DW_OP_breg10: |
| case DW_OP_breg11: |
| case DW_OP_breg12: |
| case DW_OP_breg13: |
| case DW_OP_breg14: |
| case DW_OP_breg15: |
| case DW_OP_breg16: |
| case DW_OP_breg17: |
| case DW_OP_breg18: |
| case DW_OP_breg19: |
| case DW_OP_breg20: |
| case DW_OP_breg21: |
| case DW_OP_breg22: |
| case DW_OP_breg23: |
| case DW_OP_breg24: |
| case DW_OP_breg25: |
| case DW_OP_breg26: |
| case DW_OP_breg27: |
| case DW_OP_breg28: |
| case DW_OP_breg29: |
| case DW_OP_breg30: |
| case DW_OP_breg31: |
| op_ptr = read_sleb128 (op_ptr, &offset); |
| result = _Unwind_GetGR (context, op - DW_OP_breg0) + offset; |
| break; |
| case DW_OP_bregx: |
| op_ptr = read_uleb128 (op_ptr, ®); |
| op_ptr = read_sleb128 (op_ptr, &offset); |
| result = _Unwind_GetGR (context, reg) + (_Unwind_Word)offset; |
| break; |
| |
| case DW_OP_dup: |
| gcc_assert (stack_elt); |
| result = stack[stack_elt - 1]; |
| break; |
| |
| case DW_OP_drop: |
| gcc_assert (stack_elt); |
| stack_elt -= 1; |
| goto no_push; |
| |
| case DW_OP_pick: |
| offset = *op_ptr++; |
| gcc_assert (offset < stack_elt - 1); |
| result = stack[stack_elt - 1 - offset]; |
| break; |
| |
| case DW_OP_over: |
| gcc_assert (stack_elt >= 2); |
| result = stack[stack_elt - 2]; |
| break; |
| |
| case DW_OP_swap: |
| { |
| _Unwind_Word t; |
| gcc_assert (stack_elt >= 2); |
| t = stack[stack_elt - 1]; |
| stack[stack_elt - 1] = stack[stack_elt - 2]; |
| stack[stack_elt - 2] = t; |
| goto no_push; |
| } |
| |
| case DW_OP_rot: |
| { |
| _Unwind_Word t1, t2, t3; |
| |
| gcc_assert (stack_elt >= 3); |
| t1 = stack[stack_elt - 1]; |
| t2 = stack[stack_elt - 2]; |
| t3 = stack[stack_elt - 3]; |
| stack[stack_elt - 1] = t2; |
| stack[stack_elt - 2] = t3; |
| stack[stack_elt - 3] = t1; |
| goto no_push; |
| } |
| |
| case DW_OP_deref: |
| case DW_OP_deref_size: |
| case DW_OP_abs: |
| case DW_OP_neg: |
| case DW_OP_not: |
| case DW_OP_plus_uconst: |
| /* Unary operations. */ |
| gcc_assert (stack_elt); |
| stack_elt -= 1; |
| |
| result = stack[stack_elt]; |
| |
| switch (op) |
| { |
| case DW_OP_deref: |
| { |
| void *ptr = (void *) (_Unwind_Ptr) result; |
| result = (_Unwind_Ptr) read_pointer (ptr); |
| } |
| break; |
| |
| case DW_OP_deref_size: |
| { |
| void *ptr = (void *) (_Unwind_Ptr) result; |
| switch (*op_ptr++) |
| { |
| case 1: |
| result = read_1u (ptr); |
| break; |
| case 2: |
| result = read_2u (ptr); |
| break; |
| case 4: |
| result = read_4u (ptr); |
| break; |
| case 8: |
| result = read_8u (ptr); |
| break; |
| default: |
| gcc_unreachable (); |
| } |
| } |
| break; |
| |
| case DW_OP_abs: |
| if ((_Unwind_Sword) result < 0) |
| result = -result; |
| break; |
| case DW_OP_neg: |
| result = -result; |
| break; |
| case DW_OP_not: |
| result = ~result; |
| break; |
| case DW_OP_plus_uconst: |
| op_ptr = read_uleb128 (op_ptr, &utmp); |
| result += (_Unwind_Word)utmp; |
| break; |
| |
| default: |
| gcc_unreachable (); |
| } |
| break; |
| |
| case DW_OP_and: |
| case DW_OP_div: |
| case DW_OP_minus: |
| case DW_OP_mod: |
| case DW_OP_mul: |
| case DW_OP_or: |
| case DW_OP_plus: |
| case DW_OP_shl: |
| case DW_OP_shr: |
| case DW_OP_shra: |
| case DW_OP_xor: |
| case DW_OP_le: |
| case DW_OP_ge: |
| case DW_OP_eq: |
| case DW_OP_lt: |
| case DW_OP_gt: |
| case DW_OP_ne: |
| { |
| /* Binary operations. */ |
| _Unwind_Word first, second; |
| gcc_assert (stack_elt >= 2); |
| stack_elt -= 2; |
| |
| second = stack[stack_elt]; |
| first = stack[stack_elt + 1]; |
| |
| switch (op) |
| { |
| case DW_OP_and: |
| result = second & first; |
| break; |
| case DW_OP_div: |
| result = (_Unwind_Sword) second / (_Unwind_Sword) first; |
| break; |
| case DW_OP_minus: |
| result = second - first; |
| break; |
| case DW_OP_mod: |
| result = second % first; |
| break; |
| case DW_OP_mul: |
| result = second * first; |
| break; |
| case DW_OP_or: |
| result = second | first; |
| break; |
| case DW_OP_plus: |
| result = second + first; |
| break; |
| case DW_OP_shl: |
| result = second << first; |
| break; |
| case DW_OP_shr: |
| result = second >> first; |
| break; |
| case DW_OP_shra: |
| result = (_Unwind_Sword) second >> first; |
| break; |
| case DW_OP_xor: |
| result = second ^ first; |
| break; |
| case DW_OP_le: |
| result = (_Unwind_Sword) second <= (_Unwind_Sword) first; |
| break; |
| case DW_OP_ge: |
| result = (_Unwind_Sword) second >= (_Unwind_Sword) first; |
| break; |
| case DW_OP_eq: |
| result = (_Unwind_Sword) second == (_Unwind_Sword) first; |
| break; |
| case DW_OP_lt: |
| result = (_Unwind_Sword) second < (_Unwind_Sword) first; |
| break; |
| case DW_OP_gt: |
| result = (_Unwind_Sword) second > (_Unwind_Sword) first; |
| break; |
| case DW_OP_ne: |
| result = (_Unwind_Sword) second != (_Unwind_Sword) first; |
| break; |
| |
| default: |
| gcc_unreachable (); |
| } |
| } |
| break; |
| |
| case DW_OP_skip: |
| offset = read_2s (op_ptr); |
| op_ptr += 2; |
| op_ptr += offset; |
| goto no_push; |
| |
| case DW_OP_bra: |
| gcc_assert (stack_elt); |
| stack_elt -= 1; |
| |
| offset = read_2s (op_ptr); |
| op_ptr += 2; |
| if (stack[stack_elt] != 0) |
| op_ptr += offset; |
| goto no_push; |
| |
| case DW_OP_nop: |
| goto no_push; |
| |
| default: |
| gcc_unreachable (); |
| } |
| |
| /* Most things push a result value. */ |
| gcc_assert ((size_t) stack_elt < sizeof(stack)/sizeof(*stack)); |
| stack[stack_elt++] = result; |
| no_push:; |
| } |
| |
| /* We were executing this program to get a value. It should be |
| at top of stack. */ |
| gcc_assert (stack_elt); |
| stack_elt -= 1; |
| return stack[stack_elt]; |
| } |
| |
| |
| /* Decode DWARF 2 call frame information. Takes pointers the |
| instruction sequence to decode, current register information and |
| CIE info, and the PC range to evaluate. */ |
| |
| static void |
| execute_cfa_program (const unsigned char *insn_ptr, |
| const unsigned char *insn_end, |
| struct _Unwind_Context *context, |
| _Unwind_FrameState *fs) |
| { |
| struct frame_state_reg_info *unused_rs = NULL; |
| |
| /* Don't allow remember/restore between CIE and FDE programs. */ |
| fs->regs.prev = NULL; |
| |
| /* The comparison with the return address uses < rather than <= because |
| we are only interested in the effects of code before the call; for a |
| noreturn function, the return address may point to unrelated code with |
| a different stack configuration that we are not interested in. We |
| assume that the call itself is unwind info-neutral; if not, or if |
| there are delay instructions that adjust the stack, these must be |
| reflected at the point immediately before the call insn. |
| In signal frames, return address is after last completed instruction, |
| so we add 1 to return address to make the comparison <=. */ |
| while (insn_ptr < insn_end |
| && fs->pc < context->ra + _Unwind_IsSignalFrame (context)) |
| { |
| unsigned char insn = *insn_ptr++; |
| _uleb128_t reg, utmp; |
| _sleb128_t offset, stmp; |
| |
| if ((insn & 0xc0) == DW_CFA_advance_loc) |
| fs->pc += (insn & 0x3f) * fs->code_align; |
| else if ((insn & 0xc0) == DW_CFA_offset) |
| { |
| reg = insn & 0x3f; |
| insn_ptr = read_uleb128 (insn_ptr, &utmp); |
| offset = (_Unwind_Sword) utmp * fs->data_align; |
| reg = DWARF_REG_TO_UNWIND_COLUMN (reg); |
| if (UNWIND_COLUMN_IN_RANGE (reg)) |
| { |
| fs->regs.reg[reg].how = REG_SAVED_OFFSET; |
| fs->regs.reg[reg].loc.offset = offset; |
| } |
| } |
| else if ((insn & 0xc0) == DW_CFA_restore) |
| { |
| reg = insn & 0x3f; |
| reg = DWARF_REG_TO_UNWIND_COLUMN (reg); |
| if (UNWIND_COLUMN_IN_RANGE (reg)) |
| fs->regs.reg[reg].how = REG_UNSAVED; |
| } |
| else switch (insn) |
| { |
| case DW_CFA_set_loc: |
| { |
| _Unwind_Ptr pc; |
| |
| insn_ptr = read_encoded_value (context, fs->fde_encoding, |
| insn_ptr, &pc); |
| fs->pc = (void *) pc; |
| } |
| break; |
| |
| case DW_CFA_advance_loc1: |
| fs->pc += read_1u (insn_ptr) * fs->code_align; |
| insn_ptr += 1; |
| break; |
| case DW_CFA_advance_loc2: |
| fs->pc += read_2u (insn_ptr) * fs->code_align; |
| insn_ptr += 2; |
| break; |
| case DW_CFA_advance_loc4: |
| fs->pc += read_4u (insn_ptr) * fs->code_align; |
| insn_ptr += 4; |
| break; |
| |
| case DW_CFA_offset_extended: |
| insn_ptr = read_uleb128 (insn_ptr, ®); |
| insn_ptr = read_uleb128 (insn_ptr, &utmp); |
| offset = (_Unwind_Sword) utmp * fs->data_align; |
| reg = DWARF_REG_TO_UNWIND_COLUMN (reg); |
| if (UNWIND_COLUMN_IN_RANGE (reg)) |
| { |
| fs->regs.reg[reg].how = REG_SAVED_OFFSET; |
| fs->regs.reg[reg].loc.offset = offset; |
| } |
| break; |
| |
| case DW_CFA_restore_extended: |
| insn_ptr = read_uleb128 (insn_ptr, ®); |
| /* FIXME, this is wrong; the CIE might have said that the |
| register was saved somewhere. */ |
| reg = DWARF_REG_TO_UNWIND_COLUMN (reg); |
| if (UNWIND_COLUMN_IN_RANGE (reg)) |
| fs->regs.reg[reg].how = REG_UNSAVED; |
| break; |
| |
| case DW_CFA_same_value: |
| insn_ptr = read_uleb128 (insn_ptr, ®); |
| reg = DWARF_REG_TO_UNWIND_COLUMN (reg); |
| if (UNWIND_COLUMN_IN_RANGE (reg)) |
| fs->regs.reg[reg].how = REG_UNSAVED; |
| break; |
| |
| case DW_CFA_undefined: |
| insn_ptr = read_uleb128 (insn_ptr, ®); |
| reg = DWARF_REG_TO_UNWIND_COLUMN (reg); |
| if (UNWIND_COLUMN_IN_RANGE (reg)) |
| fs->regs.reg[reg].how = REG_UNDEFINED; |
| break; |
| |
| case DW_CFA_nop: |
| break; |
| |
| case DW_CFA_register: |
| { |
| _uleb128_t reg2; |
| insn_ptr = read_uleb128 (insn_ptr, ®); |
| insn_ptr = read_uleb128 (insn_ptr, ®2); |
| reg = DWARF_REG_TO_UNWIND_COLUMN (reg); |
| if (UNWIND_COLUMN_IN_RANGE (reg)) |
| { |
| fs->regs.reg[reg].how = REG_SAVED_REG; |
| fs->regs.reg[reg].loc.reg = (_Unwind_Word)reg2; |
| } |
| } |
| break; |
| |
| case DW_CFA_remember_state: |
| { |
| struct frame_state_reg_info *new_rs; |
| if (unused_rs) |
| { |
| new_rs = unused_rs; |
| unused_rs = unused_rs->prev; |
| } |
| else |
| new_rs = alloca (sizeof (struct frame_state_reg_info)); |
| |
| *new_rs = fs->regs; |
| fs->regs.prev = new_rs; |
| } |
| break; |
| |
| case DW_CFA_restore_state: |
| { |
| struct frame_state_reg_info *old_rs = fs->regs.prev; |
| fs->regs = *old_rs; |
| old_rs->prev = unused_rs; |
| unused_rs = old_rs; |
| } |
| break; |
| |
| case DW_CFA_def_cfa: |
| insn_ptr = read_uleb128 (insn_ptr, &utmp); |
| fs->regs.cfa_reg = (_Unwind_Word)utmp; |
| insn_ptr = read_uleb128 (insn_ptr, &utmp); |
| fs->regs.cfa_offset = (_Unwind_Word)utmp; |
| fs->regs.cfa_how = CFA_REG_OFFSET; |
| break; |
| |
| case DW_CFA_def_cfa_register: |
| insn_ptr = read_uleb128 (insn_ptr, &utmp); |
| fs->regs.cfa_reg = (_Unwind_Word)utmp; |
| fs->regs.cfa_how = CFA_REG_OFFSET; |
| break; |
| |
| case DW_CFA_def_cfa_offset: |
| insn_ptr = read_uleb128 (insn_ptr, &utmp); |
| fs->regs.cfa_offset = utmp; |
| /* cfa_how deliberately not set. */ |
| break; |
| |
| case DW_CFA_def_cfa_expression: |
| fs->regs.cfa_exp = insn_ptr; |
| fs->regs.cfa_how = CFA_EXP; |
| insn_ptr = read_uleb128 (insn_ptr, &utmp); |
| insn_ptr += utmp; |
| break; |
| |
| case DW_CFA_expression: |
| insn_ptr = read_uleb128 (insn_ptr, ®); |
| reg = DWARF_REG_TO_UNWIND_COLUMN (reg); |
| if (UNWIND_COLUMN_IN_RANGE (reg)) |
| { |
| fs->regs.reg[reg].how = REG_SAVED_EXP; |
| fs->regs.reg[reg].loc.exp = insn_ptr; |
| } |
| insn_ptr = read_uleb128 (insn_ptr, &utmp); |
| insn_ptr += utmp; |
| break; |
| |
| /* Dwarf3. */ |
| case DW_CFA_offset_extended_sf: |
| insn_ptr = read_uleb128 (insn_ptr, ®); |
| insn_ptr = read_sleb128 (insn_ptr, &stmp); |
| offset = stmp * fs->data_align; |
| reg = DWARF_REG_TO_UNWIND_COLUMN (reg); |
| if (UNWIND_COLUMN_IN_RANGE (reg)) |
| { |
| fs->regs.reg[reg].how = REG_SAVED_OFFSET; |
| fs->regs.reg[reg].loc.offset = offset; |
| } |
| break; |
| |
| case DW_CFA_def_cfa_sf: |
| insn_ptr = read_uleb128 (insn_ptr, &utmp); |
| fs->regs.cfa_reg = (_Unwind_Word)utmp; |
| insn_ptr = read_sleb128 (insn_ptr, &stmp); |
| fs->regs.cfa_offset = (_Unwind_Sword)stmp; |
| fs->regs.cfa_how = CFA_REG_OFFSET; |
| fs->regs.cfa_offset *= fs->data_align; |
| break; |
| |
| case DW_CFA_def_cfa_offset_sf: |
| insn_ptr = read_sleb128 (insn_ptr, &stmp); |
| fs->regs.cfa_offset = (_Unwind_Sword)stmp; |
| fs->regs.cfa_offset *= fs->data_align; |
| /* cfa_how deliberately not set. */ |
| break; |
| |
| case DW_CFA_val_offset: |
| insn_ptr = read_uleb128 (insn_ptr, ®); |
| insn_ptr = read_uleb128 (insn_ptr, &utmp); |
| offset = (_Unwind_Sword) utmp * fs->data_align; |
| reg = DWARF_REG_TO_UNWIND_COLUMN (reg); |
| if (UNWIND_COLUMN_IN_RANGE (reg)) |
| { |
| fs->regs.reg[reg].how = REG_SAVED_VAL_OFFSET; |
| fs->regs.reg[reg].loc.offset = offset; |
| } |
| break; |
| |
| case DW_CFA_val_offset_sf: |
| insn_ptr = read_uleb128 (insn_ptr, ®); |
| insn_ptr = read_sleb128 (insn_ptr, &stmp); |
| offset = stmp * fs->data_align; |
| reg = DWARF_REG_TO_UNWIND_COLUMN (reg); |
| if (UNWIND_COLUMN_IN_RANGE (reg)) |
| { |
| fs->regs.reg[reg].how = REG_SAVED_VAL_OFFSET; |
| fs->regs.reg[reg].loc.offset = offset; |
| } |
| break; |
| |
| case DW_CFA_val_expression: |
| insn_ptr = read_uleb128 (insn_ptr, ®); |
| reg = DWARF_REG_TO_UNWIND_COLUMN (reg); |
| if (UNWIND_COLUMN_IN_RANGE (reg)) |
| { |
| fs->regs.reg[reg].how = REG_SAVED_VAL_EXP; |
| fs->regs.reg[reg].loc.exp = insn_ptr; |
| } |
| insn_ptr = read_uleb128 (insn_ptr, &utmp); |
| insn_ptr += utmp; |
| break; |
| |
| case DW_CFA_GNU_window_save: |
| #if defined (__aarch64__) && !defined (__ILP32__) |
| /* This CFA is multiplexed with Sparc. On AArch64 it's used to toggle |
| return address signing status. */ |
| fs->regs.reg[DWARF_REGNUM_AARCH64_RA_STATE].loc.offset ^= 1; |
| #else |
| /* ??? Hardcoded for SPARC register window configuration. */ |
| if (__LIBGCC_DWARF_FRAME_REGISTERS__ >= 32) |
| for (reg = 16; reg < 32; ++reg) |
| { |
| fs->regs.reg[reg].how = REG_SAVED_OFFSET; |
| fs->regs.reg[reg].loc.offset = (reg - 16) * sizeof (void *); |
| } |
| #endif |
| break; |
| |
| case DW_CFA_GNU_args_size: |
| insn_ptr = read_uleb128 (insn_ptr, &utmp); |
| context->args_size = (_Unwind_Word)utmp; |
| break; |
| |
| case DW_CFA_GNU_negative_offset_extended: |
| /* Obsoleted by DW_CFA_offset_extended_sf, but used by |
| older PowerPC code. */ |
| insn_ptr = read_uleb128 (insn_ptr, ®); |
| insn_ptr = read_uleb128 (insn_ptr, &utmp); |
| offset = (_Unwind_Word) utmp * fs->data_align; |
| reg = DWARF_REG_TO_UNWIND_COLUMN (reg); |
| if (UNWIND_COLUMN_IN_RANGE (reg)) |
| { |
| fs->regs.reg[reg].how = REG_SAVED_OFFSET; |
| fs->regs.reg[reg].loc.offset = -offset; |
| } |
| break; |
| |
| default: |
| gcc_unreachable (); |
| } |
| } |
| } |
| |
| /* Given the _Unwind_Context CONTEXT for a stack frame, look up the FDE for |
| its caller and decode it into FS. This function also sets the |
| args_size and lsda members of CONTEXT, as they are really information |
| about the caller's frame. */ |
| |
| static _Unwind_Reason_Code |
| uw_frame_state_for (struct _Unwind_Context *context, _Unwind_FrameState *fs) |
| { |
| const struct dwarf_fde *fde; |
| const struct dwarf_cie *cie; |
| const unsigned char *aug, *insn, *end; |
| |
| memset (fs, 0, sizeof (*fs)); |
| context->args_size = 0; |
| context->lsda = 0; |
| |
| if (context->ra == 0) |
| return _URC_END_OF_STACK; |
| |
| fde = _Unwind_Find_FDE (context->ra + _Unwind_IsSignalFrame (context) - 1, |
| &context->bases); |
| if (fde == NULL) |
| { |
| #ifdef MD_FALLBACK_FRAME_STATE_FOR |
| /* Couldn't find frame unwind info for this function. Try a |
| target-specific fallback mechanism. This will necessarily |
| not provide a personality routine or LSDA. */ |
| return MD_FALLBACK_FRAME_STATE_FOR (context, fs); |
| #else |
| return _URC_END_OF_STACK; |
| #endif |
| } |
| |
| fs->pc = context->bases.func; |
| |
| cie = get_cie (fde); |
| insn = extract_cie_info (cie, context, fs); |
| if (insn == NULL) |
| /* CIE contained unknown augmentation. */ |
| return _URC_FATAL_PHASE1_ERROR; |
| |
| /* First decode all the insns in the CIE. */ |
| end = (const unsigned char *) next_fde ((const struct dwarf_fde *) cie); |
| execute_cfa_program (insn, end, context, fs); |
| |
| /* Locate augmentation for the fde. */ |
| aug = (const unsigned char *) fde + sizeof (*fde); |
| aug += 2 * size_of_encoded_value (fs->fde_encoding); |
| insn = NULL; |
| if (fs->saw_z) |
| { |
| _uleb128_t i; |
| aug = read_uleb128 (aug, &i); |
| insn = aug + i; |
| } |
| if (fs->lsda_encoding != DW_EH_PE_omit) |
| { |
| _Unwind_Ptr lsda; |
| |
| aug = read_encoded_value (context, fs->lsda_encoding, aug, &lsda); |
| context->lsda = (void *) lsda; |
| } |
| |
| /* Then the insns in the FDE up to our target PC. */ |
| if (insn == NULL) |
| insn = aug; |
| end = (const unsigned char *) next_fde (fde); |
| execute_cfa_program (insn, end, context, fs); |
| |
| return _URC_NO_REASON; |
| } |
| |
| typedef struct frame_state |
| { |
| void *cfa; |
| void *eh_ptr; |
| long cfa_offset; |
| long args_size; |
| long reg_or_offset[PRE_GCC3_DWARF_FRAME_REGISTERS+1]; |
| unsigned short cfa_reg; |
| unsigned short retaddr_column; |
| char saved[PRE_GCC3_DWARF_FRAME_REGISTERS+1]; |
| } frame_state; |
| |
| struct frame_state * __frame_state_for (void *, struct frame_state *); |
| |
| /* Called from pre-G++ 3.0 __throw to find the registers to restore for |
| a given PC_TARGET. The caller should allocate a local variable of |
| `struct frame_state' and pass its address to STATE_IN. */ |
| |
| struct frame_state * |
| __frame_state_for (void *pc_target, struct frame_state *state_in) |
| { |
| struct _Unwind_Context context; |
| _Unwind_FrameState fs; |
| int reg; |
| |
| memset (&context, 0, sizeof (struct _Unwind_Context)); |
| if (!ASSUME_EXTENDED_UNWIND_CONTEXT) |
| context.flags = EXTENDED_CONTEXT_BIT; |
| context.ra = pc_target + 1; |
| |
| if (uw_frame_state_for (&context, &fs) != _URC_NO_REASON) |
| return 0; |
| |
| /* We have no way to pass a location expression for the CFA to our |
| caller. It wouldn't understand it anyway. */ |
| if (fs.regs.cfa_how == CFA_EXP) |
| return 0; |
| |
| for (reg = 0; reg < PRE_GCC3_DWARF_FRAME_REGISTERS + 1; reg++) |
| { |
| state_in->saved[reg] = fs.regs.reg[reg].how; |
| switch (state_in->saved[reg]) |
| { |
| case REG_SAVED_REG: |
| state_in->reg_or_offset[reg] = fs.regs.reg[reg].loc.reg; |
| break; |
| case REG_SAVED_OFFSET: |
| state_in->reg_or_offset[reg] = fs.regs.reg[reg].loc.offset; |
| break; |
| default: |
| state_in->reg_or_offset[reg] = 0; |
| break; |
| } |
| } |
| |
| state_in->cfa_offset = fs.regs.cfa_offset; |
| state_in->cfa_reg = fs.regs.cfa_reg; |
| state_in->retaddr_column = fs.retaddr_column; |
| state_in->args_size = context.args_size; |
| state_in->eh_ptr = fs.eh_ptr; |
| |
| return state_in; |
| } |
| |
| typedef union { _Unwind_Ptr ptr; _Unwind_Word word; } _Unwind_SpTmp; |
| |
| static inline void |
| _Unwind_SetSpColumn (struct _Unwind_Context *context, void *cfa, |
| _Unwind_SpTmp *tmp_sp) |
| { |
| int size = dwarf_reg_size_table[__builtin_dwarf_sp_column ()]; |
| |
| if (size == sizeof(_Unwind_Ptr)) |
| tmp_sp->ptr = (_Unwind_Ptr) cfa; |
| else |
| { |
| gcc_assert (size == sizeof(_Unwind_Word)); |
| tmp_sp->word = (_Unwind_Ptr) cfa; |
| } |
| _Unwind_SetGRPtr (context, __builtin_dwarf_sp_column (), tmp_sp); |
| } |
| |
| static void |
| uw_update_context_1 (struct _Unwind_Context *context, _Unwind_FrameState *fs) |
| { |
| struct _Unwind_Context orig_context = *context; |
| void *cfa; |
| long i; |
| |
| #ifdef __LIBGCC_EH_RETURN_STACKADJ_RTX__ |
| /* Special handling here: Many machines do not use a frame pointer, |
| and track the CFA only through offsets from the stack pointer from |
| one frame to the next. In this case, the stack pointer is never |
| stored, so it has no saved address in the context. What we do |
| have is the CFA from the previous stack frame. |
| |
| In very special situations (such as unwind info for signal return), |
| there may be location expressions that use the stack pointer as well. |
| |
| Do this conditionally for one frame. This allows the unwind info |
| for one frame to save a copy of the stack pointer from the previous |
| frame, and be able to use much easier CFA mechanisms to do it. |
| Always zap the saved stack pointer value for the next frame; carrying |
| the value over from one frame to another doesn't make sense. */ |
| |
| _Unwind_SpTmp tmp_sp; |
| |
| if (!_Unwind_GetGRPtr (&orig_context, __builtin_dwarf_sp_column ())) |
| _Unwind_SetSpColumn (&orig_context, context->cfa, &tmp_sp); |
| _Unwind_SetGRPtr (context, __builtin_dwarf_sp_column (), NULL); |
| #endif |
| |
| /* Compute this frame's CFA. */ |
| switch (fs->regs.cfa_how) |
| { |
| case CFA_REG_OFFSET: |
| cfa = _Unwind_GetPtr (&orig_context, fs->regs.cfa_reg); |
| cfa += fs->regs.cfa_offset; |
| break; |
| |
| case CFA_EXP: |
| { |
| const unsigned char *exp = fs->regs.cfa_exp; |
| _uleb128_t len; |
| |
| exp = read_uleb128 (exp, &len); |
| cfa = (void *) (_Unwind_Ptr) |
| execute_stack_op (exp, exp + len, &orig_context, 0); |
| break; |
| } |
| |
| default: |
| gcc_unreachable (); |
| } |
| context->cfa = cfa; |
| |
| /* Compute the addresses of all registers saved in this frame. */ |
| for (i = 0; i < __LIBGCC_DWARF_FRAME_REGISTERS__ + 1; ++i) |
| switch (fs->regs.reg[i].how) |
| { |
| case REG_UNSAVED: |
| case REG_UNDEFINED: |
| break; |
| |
| case REG_SAVED_OFFSET: |
| _Unwind_SetGRPtr (context, i, |
| (void *) (cfa + fs->regs.reg[i].loc.offset)); |
| break; |
| |
| case REG_SAVED_REG: |
| if (_Unwind_GRByValue (&orig_context, fs->regs.reg[i].loc.reg)) |
| _Unwind_SetGRValue (context, i, |
| _Unwind_GetGR (&orig_context, |
| fs->regs.reg[i].loc.reg)); |
| else |
| _Unwind_SetGRPtr (context, i, |
| _Unwind_GetGRPtr (&orig_context, |
| fs->regs.reg[i].loc.reg)); |
| break; |
| |
| case REG_SAVED_EXP: |
| { |
| const unsigned char *exp = fs->regs.reg[i].loc.exp; |
| _uleb128_t len; |
| _Unwind_Ptr val; |
| |
| exp = read_uleb128 (exp, &len); |
| val = execute_stack_op (exp, exp + len, &orig_context, |
| (_Unwind_Ptr) cfa); |
| _Unwind_SetGRPtr (context, i, (void *) val); |
| } |
| break; |
| |
| case REG_SAVED_VAL_OFFSET: |
| _Unwind_SetGRValue (context, i, |
| (_Unwind_Internal_Ptr) |
| (cfa + fs->regs.reg[i].loc.offset)); |
| break; |
| |
| case REG_SAVED_VAL_EXP: |
| { |
| const unsigned char *exp = fs->regs.reg[i].loc.exp; |
| _uleb128_t len; |
| _Unwind_Ptr val; |
| |
| exp = read_uleb128 (exp, &len); |
| val = execute_stack_op (exp, exp + len, &orig_context, |
| (_Unwind_Ptr) cfa); |
| _Unwind_SetGRValue (context, i, val); |
| } |
| break; |
| } |
| |
| _Unwind_SetSignalFrame (context, fs->signal_frame); |
| |
| #ifdef MD_FROB_UPDATE_CONTEXT |
| MD_FROB_UPDATE_CONTEXT (context, fs); |
| #endif |
| } |
| |
| /* CONTEXT describes the unwind state for a frame, and FS describes the FDE |
| of its caller. Update CONTEXT to refer to the caller as well. Note |
| that the args_size and lsda members are not updated here, but later in |
| uw_frame_state_for. */ |
| |
| static void |
| uw_update_context (struct _Unwind_Context *context, _Unwind_FrameState *fs) |
| { |
| uw_update_context_1 (context, fs); |
| |
| /* In general this unwinder doesn't make any distinction between |
| undefined and same_value rule. Call-saved registers are assumed |
| to have same_value rule by default and explicit undefined |
| rule is handled like same_value. The only exception is |
| DW_CFA_undefined on retaddr_column which is supposed to |
| mark outermost frame in DWARF 3. */ |
| if (fs->regs.reg[DWARF_REG_TO_UNWIND_COLUMN (fs->retaddr_column)].how |
| == REG_UNDEFINED) |
| /* uw_frame_state_for uses context->ra == 0 check to find outermost |
| stack frame. */ |
| context->ra = 0; |
| else |
| { |
| /* Compute the return address now, since the return address column |
| can change from frame to frame. */ |
| void *ret_addr; |
| #ifdef MD_DEMANGLE_RETURN_ADDR |
| _Unwind_Word ra = _Unwind_GetGR (context, fs->retaddr_column); |
| ret_addr = MD_DEMANGLE_RETURN_ADDR (context, fs, ra); |
| #else |
| ret_addr = _Unwind_GetPtr (context, fs->retaddr_column); |
| #endif |
| context->ra = __builtin_extract_return_addr (ret_addr); |
| } |
| } |
| |
| static void |
| uw_advance_context (struct _Unwind_Context *context, _Unwind_FrameState *fs) |
| { |
| uw_update_context (context, fs); |
| } |
| |
| /* Fill in CONTEXT for top-of-stack. The only valid registers at this |
| level will be the return address and the CFA. */ |
| |
| #define uw_init_context(CONTEXT) \ |
| do \ |
| { \ |
| /* Do any necessary initialization to access arbitrary stack frames. \ |
| On the SPARC, this means flushing the register windows. */ \ |
| __builtin_unwind_init (); \ |
| uw_init_context_1 (CONTEXT, __builtin_dwarf_cfa (), \ |
| __builtin_return_address (0)); \ |
| } \ |
| while (0) |
| |
| static inline void |
| init_dwarf_reg_size_table (void) |
| { |
| __builtin_init_dwarf_reg_size_table (dwarf_reg_size_table); |
| } |
| |
| static void __attribute__((noinline)) |
| uw_init_context_1 (struct _Unwind_Context *context, |
| void *outer_cfa, void *outer_ra) |
| { |
| void *ra = __builtin_extract_return_addr (__builtin_return_address (0)); |
| _Unwind_FrameState fs; |
| _Unwind_SpTmp sp_slot; |
| _Unwind_Reason_Code code; |
| |
| memset (context, 0, sizeof (struct _Unwind_Context)); |
| context->ra = ra; |
| if (!ASSUME_EXTENDED_UNWIND_CONTEXT) |
| context->flags = EXTENDED_CONTEXT_BIT; |
| |
| code = uw_frame_state_for (context, &fs); |
| gcc_assert (code == _URC_NO_REASON); |
| |
| #if __GTHREADS |
| { |
| static __gthread_once_t once_regsizes = __GTHREAD_ONCE_INIT; |
| if (__gthread_once (&once_regsizes, init_dwarf_reg_size_table) != 0 |
| && dwarf_reg_size_table[0] == 0) |
| init_dwarf_reg_size_table (); |
| } |
| #else |
| if (dwarf_reg_size_table[0] == 0) |
| init_dwarf_reg_size_table (); |
| #endif |
| |
| /* Force the frame state to use the known cfa value. */ |
| _Unwind_SetSpColumn (context, outer_cfa, &sp_slot); |
| fs.regs.cfa_how = CFA_REG_OFFSET; |
| fs.regs.cfa_reg = __builtin_dwarf_sp_column (); |
| fs.regs.cfa_offset = 0; |
| |
| uw_update_context_1 (context, &fs); |
| |
| /* If the return address column was saved in a register in the |
| initialization context, then we can't see it in the given |
| call frame data. So have the initialization context tell us. */ |
| context->ra = __builtin_extract_return_addr (outer_ra); |
| } |
| |
| static void _Unwind_DebugHook (void *, void *) |
| __attribute__ ((__noinline__, __used__, __noclone__)); |
| |
| /* This function is called during unwinding. It is intended as a hook |
| for a debugger to intercept exceptions. CFA is the CFA of the |
| target frame. HANDLER is the PC to which control will be |
| transferred. */ |
| static void |
| _Unwind_DebugHook (void *cfa __attribute__ ((__unused__)), |
| void *handler __attribute__ ((__unused__))) |
| { |
| /* We only want to use stap probes starting with v3. Earlier |
| versions added too much startup cost. */ |
| #if defined (HAVE_SYS_SDT_H) && defined (STAP_PROBE2) && _SDT_NOTE_TYPE >= 3 |
| STAP_PROBE2 (libgcc, unwind, cfa, handler); |
| #else |
| asm (""); |
| #endif |
| } |
| |
| /* Install TARGET into CURRENT so that we can return to it. This is a |
| macro because __builtin_eh_return must be invoked in the context of |
| our caller. FRAMES is a number of frames to be unwind. |
| _Unwind_Frames_Extra is a macro to do additional work during unwinding |
| if needed, for example shadow stack pointer adjustment for Intel CET |
| technology. */ |
| |
| #define uw_install_context(CURRENT, TARGET, FRAMES) \ |
| do \ |
| { \ |
| long offset = uw_install_context_1 ((CURRENT), (TARGET)); \ |
| void *handler = __builtin_frob_return_addr ((TARGET)->ra); \ |
| _Unwind_DebugHook ((TARGET)->cfa, handler); \ |
| _Unwind_Frames_Extra (FRAMES); \ |
| __builtin_eh_return (offset, handler); \ |
| } \ |
| while (0) |
| |
| static long |
| uw_install_context_1 (struct _Unwind_Context *current, |
| struct _Unwind_Context *target) |
| { |
| long i; |
| _Unwind_SpTmp sp_slot; |
| |
| /* If the target frame does not have a saved stack pointer, |
| then set up the target's CFA. */ |
| if (!_Unwind_GetGRPtr (target, __builtin_dwarf_sp_column ())) |
| _Unwind_SetSpColumn (target, target->cfa, &sp_slot); |
| |
| for (i = 0; i < __LIBGCC_DWARF_FRAME_REGISTERS__; ++i) |
| { |
| void *c = (void *) (_Unwind_Internal_Ptr) current->reg[i]; |
| void *t = (void *) (_Unwind_Internal_Ptr)target->reg[i]; |
| |
| gcc_assert (current->by_value[i] == 0); |
| if (target->by_value[i] && c) |
| { |
| _Unwind_Word w; |
| _Unwind_Ptr p; |
| if (dwarf_reg_size_table[i] == sizeof (_Unwind_Word)) |
| { |
| w = (_Unwind_Internal_Ptr) t; |
| memcpy (c, &w, sizeof (_Unwind_Word)); |
| } |
| else |
| { |
| gcc_assert (dwarf_reg_size_table[i] == sizeof (_Unwind_Ptr)); |
| p = (_Unwind_Internal_Ptr) t; |
| memcpy (c, &p, sizeof (_Unwind_Ptr)); |
| } |
| } |
| else if (t && c && t != c) |
| memcpy (c, t, dwarf_reg_size_table[i]); |
| } |
| |
| /* If the current frame doesn't have a saved stack pointer, then we |
| need to rely on EH_RETURN_STACKADJ_RTX to get our target stack |
| pointer value reloaded. */ |
| if (!_Unwind_GetGRPtr (current, __builtin_dwarf_sp_column ())) |
| { |
| void *target_cfa; |
| |
| target_cfa = _Unwind_GetPtr (target, __builtin_dwarf_sp_column ()); |
| |
| /* We adjust SP by the difference between CURRENT and TARGET's CFA. */ |
| if (__LIBGCC_STACK_GROWS_DOWNWARD__) |
| return target_cfa - current->cfa + target->args_size; |
| else |
| return current->cfa - target_cfa - target->args_size; |
| } |
| return 0; |
| } |
| |
| static inline _Unwind_Ptr |
| uw_identify_context (struct _Unwind_Context *context) |
| { |
| /* The CFA is not sufficient to disambiguate the context of a function |
| interrupted by a signal before establishing its frame and the context |
| of the signal itself. */ |
| if (__LIBGCC_STACK_GROWS_DOWNWARD__) |
| return _Unwind_GetCFA (context) - _Unwind_IsSignalFrame (context); |
| else |
| return _Unwind_GetCFA (context) + _Unwind_IsSignalFrame (context); |
| } |
| |
| |
| #include "unwind.inc" |
| |
| #if defined (USE_GAS_SYMVER) && defined (SHARED) && defined (USE_LIBUNWIND_EXCEPTIONS) |
| alias (_Unwind_Backtrace); |
| alias (_Unwind_DeleteException); |
| alias (_Unwind_FindEnclosingFunction); |
| alias (_Unwind_ForcedUnwind); |
| alias (_Unwind_GetDataRelBase); |
| alias (_Unwind_GetTextRelBase); |
| alias (_Unwind_GetCFA); |
| alias (_Unwind_GetGR); |
| alias (_Unwind_GetIP); |
| alias (_Unwind_GetLanguageSpecificData); |
| alias (_Unwind_GetRegionStart); |
| alias (_Unwind_RaiseException); |
| alias (_Unwind_Resume); |
| alias (_Unwind_Resume_or_Rethrow); |
| alias (_Unwind_SetGR); |
| alias (_Unwind_SetIP); |
| #endif |
| |
| #endif /* !USING_SJLJ_EXCEPTIONS */ |