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- /* Common unwinding code for ARM EABI and C6X.
- Copyright (C) 2004-2022 Free Software Foundation, Inc.
- Contributed by Paul Brook
- This file 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.
- This file 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 "unwind.h"
- /* Used for SystemTap unwinder probe. */
- #ifdef HAVE_SYS_SDT_H
- #include <sys/sdt.h>
- #endif
- #if __FDPIC__
- /* Load r7 with rt_sigreturn value. */
- #define ARM_SET_R7_RT_SIGRETURN 0xe3a070ad /* mov r7, #0xad */
- #define THUMB2_SET_R7_RT_SIGRETURN 0x07adf04f /* mov.w r7, #0xad */
- /* FDPIC jump to restorer sequence. */
- #define FDPIC_LDR_R12_WITH_FUNCDESC 0xe59fc004 /* ldr r12, [pc, #4] */
- #define FDPIC_LDR_R9_WITH_GOT 0xe59c9004 /* ldr r9, [r12, #4] */
- #define FDPIC_LDR_PC_WITH_RESTORER 0xe59cf000 /* ldr pc, [r12] */
- #define FDPIC_T2_LDR_R12_WITH_FUNCDESC 0xc008f8df /* ldr.w r12, [pc, #8] */
- #define FDPIC_T2_LDR_R9_WITH_GOT 0x9004f8dc /* ldr.w r9, [r12, #4] */
- #define FDPIC_T2_LDR_PC_WITH_RESTORER 0xf000f8dc /* ldr.w pc, [r12] */
- #define FDPIC_FUNCDESC_OFFSET 12
- /* Signal frame offsets. */
- #define ARM_NEW_RT_SIGFRAME_UCONTEXT 0x80
- #define ARM_UCONTEXT_SIGCONTEXT 0x14
- #define ARM_SIGCONTEXT_R0 0xc
- #endif
- /* Definitions for C++ runtime support routines. We make these weak
- declarations to avoid pulling in libsupc++ unnecessarily. */
- typedef unsigned char bool;
- typedef struct _ZSt9type_info type_info; /* This names C++ type_info type */
- enum __cxa_type_match_result
- {
- ctm_failed = 0,
- ctm_succeeded = 1,
- ctm_succeeded_with_ptr_to_base = 2
- };
- void __attribute__((weak)) __cxa_call_unexpected(_Unwind_Control_Block *ucbp);
- bool __attribute__((weak)) __cxa_begin_cleanup(_Unwind_Control_Block *ucbp);
- enum __cxa_type_match_result __attribute__((weak)) __cxa_type_match
- (_Unwind_Control_Block *ucbp, const type_info *rttip,
- bool is_reference, void **matched_object);
- _Unwind_Ptr __attribute__((weak))
- __gnu_Unwind_Find_exidx (_Unwind_Ptr, int *);
- #define EXIDX_CANTUNWIND 1
- #define uint32_highbit (((_uw) 1) << 31)
- #define UCB_FORCED_STOP_FN(ucbp) ((ucbp)->unwinder_cache.reserved1)
- #define UCB_PR_ADDR(ucbp) ((ucbp)->unwinder_cache.reserved2)
- #define UCB_SAVED_CALLSITE_ADDR(ucbp) ((ucbp)->unwinder_cache.reserved3)
- #define UCB_FORCED_STOP_ARG(ucbp) ((ucbp)->unwinder_cache.reserved4)
- #define UCB_PR_GOT(ucbp) ((ucbp)->unwinder_cache.reserved5)
- /* Unwind descriptors. */
- typedef struct
- {
- _uw16 length;
- _uw16 offset;
- } EHT16;
- typedef struct
- {
- _uw length;
- _uw offset;
- } EHT32;
- /* An exception index table entry. */
- typedef struct __EIT_entry
- {
- _uw fnoffset;
- _uw content;
- } __EIT_entry;
- #ifdef __FDPIC__
- /* Only used in FDPIC case. */
- struct funcdesc_t
- {
- unsigned int ptr;
- unsigned int got;
- };
- #endif
- /* Assembly helper functions. */
- /* Restore core register state. Never returns. */
- void __attribute__((noreturn)) restore_core_regs (struct core_regs *);
- /* Restore coprocessor state after phase1 unwinding. */
- static void restore_non_core_regs (phase1_vrs * vrs);
- /* A better way to do this would probably be to compare the absolute address
- with a segment relative relocation of the same symbol. */
- extern int __text_start;
- extern int __data_start;
- /* The exception index table location. */
- extern __EIT_entry __exidx_start;
- extern __EIT_entry __exidx_end;
- /* Core unwinding functions. */
- /* Calculate the address encoded by a 31-bit self-relative offset at address
- P. */
- static inline _uw selfrel_offset31 (const _uw *p);
- static _uw __gnu_unwind_get_pr_addr (int idx);
- 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
- }
- /* This is a wrapper to be called when we need to restore core registers.
- It will call `_Unwind_DebugHook' before restoring the registers, thus
- making it possible to intercept and debug exceptions.
- When calling `_Unwind_DebugHook', the first argument (the CFA) is zero
- because we are not interested in it. However, it must be there (even
- being zero) because GDB expects to find it when using the probe. */
- #define uw_restore_core_regs(TARGET, CORE) \
- do \
- { \
- void *handler = __builtin_frob_return_addr ((void *) VRS_PC (TARGET)); \
- _Unwind_DebugHook (0, handler); \
- restore_core_regs (CORE); \
- } \
- while (0)
- /* Perform a binary search for RETURN_ADDRESS in TABLE. The table contains
- NREC entries. */
- static const __EIT_entry *
- search_EIT_table (const __EIT_entry * table, int nrec, _uw return_address)
- {
- _uw next_fn;
- _uw this_fn;
- int n, left, right;
- if (nrec == 0)
- return (__EIT_entry *) 0;
- left = 0;
- right = nrec - 1;
- while (1)
- {
- n = (left + right) / 2;
- this_fn = selfrel_offset31 (&table[n].fnoffset);
- if (n != nrec - 1)
- next_fn = selfrel_offset31 (&table[n + 1].fnoffset) - 1;
- else
- next_fn = (_uw)0 - 1;
- if (return_address < this_fn)
- {
- if (n == left)
- return (__EIT_entry *) 0;
- right = n - 1;
- }
- else if (return_address <= next_fn)
- return &table[n];
- else
- left = n + 1;
- }
- }
- #if __FDPIC__
- /* VFP is not restored, but this is sufficient to allow unwinding. */
- static _Unwind_Reason_Code
- __gnu_personality_sigframe_fdpic (_Unwind_State state,
- _Unwind_Control_Block *ucbp,
- _Unwind_Context *context)
- {
- unsigned int sp;
- unsigned int pc;
- unsigned int funcdesc;
- unsigned int handler;
- unsigned int first_handler_instruction;
- int i;
- _Unwind_VRS_Get (context, _UVRSC_CORE, R_SP, _UVRSD_UINT32, &sp);
- _Unwind_VRS_Get (context, _UVRSC_CORE, R_PC, _UVRSD_UINT32, &pc);
- funcdesc = *(unsigned int *)((pc & ~1) + FDPIC_FUNCDESC_OFFSET);
- handler = *(unsigned int *)(funcdesc);
- first_handler_instruction = *(unsigned int *)(handler & ~1);
- /* Adjust SP to point to the start of registers according to
- signal type. */
- if (first_handler_instruction == ARM_SET_R7_RT_SIGRETURN
- || first_handler_instruction == THUMB2_SET_R7_RT_SIGRETURN)
- sp += ARM_NEW_RT_SIGFRAME_UCONTEXT
- + ARM_UCONTEXT_SIGCONTEXT
- + ARM_SIGCONTEXT_R0;
- else
- sp += ARM_UCONTEXT_SIGCONTEXT
- + ARM_SIGCONTEXT_R0;
- /* Restore regs saved on stack by the kernel. */
- for (i = 0; i < 16; i++)
- _Unwind_VRS_Set (context, _UVRSC_CORE, i, _UVRSD_UINT32, sp + 4 * i);
- return _URC_CONTINUE_UNWIND;
- }
- #endif
- /* Find the exception index table eintry for the given address.
- Fill in the relevant fields of the UCB.
- Returns _URC_FAILURE if an error occurred, _URC_OK on success. */
- static _Unwind_Reason_Code
- get_eit_entry (_Unwind_Control_Block *ucbp, _uw return_address)
- {
- const __EIT_entry * eitp;
- int nrec;
-
- /* The return address is the address of the instruction following the
- call instruction (plus one in thumb mode). If this was the last
- instruction in the function the address will lie in the following
- function. Subtract 2 from the address so that it points within the call
- instruction itself. */
- return_address -= 2;
- if (__gnu_Unwind_Find_exidx)
- {
- eitp = (const __EIT_entry *) __gnu_Unwind_Find_exidx (return_address,
- &nrec);
- if (!eitp)
- {
- #if __FDPIC__
- /* If we are unwinding a signal handler then perhaps we have
- reached a trampoline. Try to detect jump to restorer
- sequence. */
- _uw *pc = (_uw *)((return_address+2) & ~1);
- if ((pc[0] == FDPIC_LDR_R12_WITH_FUNCDESC
- && pc[1] == FDPIC_LDR_R9_WITH_GOT
- && pc[2] == FDPIC_LDR_PC_WITH_RESTORER)
- || (pc[0] == FDPIC_T2_LDR_R12_WITH_FUNCDESC
- && pc[1] == FDPIC_T2_LDR_R9_WITH_GOT
- && pc[2] == FDPIC_T2_LDR_PC_WITH_RESTORER))
- {
- struct funcdesc_t *funcdesc
- = (struct funcdesc_t *) &__gnu_personality_sigframe_fdpic;
- UCB_PR_ADDR (ucbp) = funcdesc->ptr;
- UCB_PR_GOT (ucbp) = funcdesc->got;
- return _URC_OK;
- }
- #endif
- UCB_PR_ADDR (ucbp) = 0;
- return _URC_FAILURE;
- }
- }
- else
- {
- eitp = &__exidx_start;
- nrec = &__exidx_end - &__exidx_start;
- }
- eitp = search_EIT_table (eitp, nrec, return_address);
- if (!eitp)
- {
- #if __FDPIC__
- /* If we are unwinding a signal handler then perhaps we have
- reached a trampoline. Try to detect jump to restorer
- sequence. */
- _uw *pc = (_uw *)((return_address+2) & ~1);
- if ((pc[0] == FDPIC_LDR_R12_WITH_FUNCDESC
- && pc[1] == FDPIC_LDR_R9_WITH_GOT
- && pc[2] == FDPIC_LDR_PC_WITH_RESTORER)
- || (pc[0] == FDPIC_T2_LDR_R12_WITH_FUNCDESC
- && pc[1] == FDPIC_T2_LDR_R9_WITH_GOT
- && pc[2] == FDPIC_T2_LDR_PC_WITH_RESTORER))
- {
- struct funcdesc_t *funcdesc
- = (struct funcdesc_t *) &__gnu_personality_sigframe_fdpic;
- UCB_PR_ADDR (ucbp) = funcdesc->ptr;
- UCB_PR_GOT (ucbp) = funcdesc->got;
- return _URC_OK;
- }
- #endif
- UCB_PR_ADDR (ucbp) = 0;
- return _URC_FAILURE;
- }
- ucbp->pr_cache.fnstart = selfrel_offset31 (&eitp->fnoffset);
- /* Can this frame be unwound at all? */
- if (eitp->content == EXIDX_CANTUNWIND)
- {
- #if __FDPIC__
- /* If we are unwinding a signal handler then perhaps we have
- reached a trampoline. Try to detect jump to restorer
- sequence. */
- _uw *pc = (_uw *)((return_address+2) & ~1);
- if ((pc[0] == FDPIC_LDR_R12_WITH_FUNCDESC
- && pc[1] == FDPIC_LDR_R9_WITH_GOT
- && pc[2] == FDPIC_LDR_PC_WITH_RESTORER)
- || (pc[0] == FDPIC_T2_LDR_R12_WITH_FUNCDESC
- && pc[1] == FDPIC_T2_LDR_R9_WITH_GOT
- && pc[2] == FDPIC_T2_LDR_PC_WITH_RESTORER))
- {
- struct funcdesc_t *funcdesc
- = (struct funcdesc_t *) &__gnu_personality_sigframe_fdpic;
- UCB_PR_ADDR (ucbp) = funcdesc->ptr;
- UCB_PR_GOT (ucbp) = funcdesc->got;
- return _URC_OK;
- }
- #endif
- UCB_PR_ADDR (ucbp) = 0;
- return _URC_END_OF_STACK;
- }
- /* Obtain the address of the "real" __EHT_Header word. */
- if (eitp->content & uint32_highbit)
- {
- /* It is immediate data. */
- ucbp->pr_cache.ehtp = (_Unwind_EHT_Header *)&eitp->content;
- ucbp->pr_cache.additional = 1;
- }
- else
- {
- /* The low 31 bits of the content field are a self-relative
- offset to an _Unwind_EHT_Entry structure. */
- ucbp->pr_cache.ehtp =
- (_Unwind_EHT_Header *) selfrel_offset31 (&eitp->content);
- ucbp->pr_cache.additional = 0;
- }
- /* Discover the personality routine address. */
- if (*ucbp->pr_cache.ehtp & (1u << 31))
- {
- /* One of the predefined standard routines. */
- _uw idx = (*(_uw *) ucbp->pr_cache.ehtp >> 24) & 0xf;
- #if __FDPIC__
- {
- struct funcdesc_t *funcdesc
- = (struct funcdesc_t *) __gnu_unwind_get_pr_addr (idx);
- if (funcdesc)
- {
- UCB_PR_ADDR (ucbp) = funcdesc->ptr;
- UCB_PR_GOT (ucbp) = funcdesc->got;
- }
- else
- UCB_PR_ADDR (ucbp) = 0;
- }
- #else
- UCB_PR_ADDR (ucbp) = __gnu_unwind_get_pr_addr (idx);
- #endif
- if (UCB_PR_ADDR (ucbp) == 0)
- {
- /* Failed */
- return _URC_FAILURE;
- }
- }
- else
- {
- /* Execute region offset to PR */
- UCB_PR_ADDR (ucbp) = selfrel_offset31 (ucbp->pr_cache.ehtp);
- #if __FDPIC__
- UCB_PR_GOT (ucbp)
- = (unsigned int) _Unwind_gnu_Find_got ((_Unwind_Ptr) UCB_PR_ADDR (ucbp));
- #endif
- }
- return _URC_OK;
- }
- /* Perform phase2 unwinding. VRS is the initial virtual register state. */
- static void __attribute__((noreturn))
- unwind_phase2 (_Unwind_Control_Block * ucbp, phase2_vrs * vrs)
- {
- _Unwind_Reason_Code pr_result;
- do
- {
- /* Find the entry for this routine. */
- if (get_eit_entry (ucbp, VRS_PC(vrs)) != _URC_OK)
- abort ();
- UCB_SAVED_CALLSITE_ADDR (ucbp) = VRS_PC(vrs);
- /* Call the pr to decide what to do. */
- #if __FDPIC__
- {
- volatile struct funcdesc_t funcdesc;
- funcdesc.ptr = UCB_PR_ADDR (ucbp);
- funcdesc.got = UCB_PR_GOT (ucbp);
- pr_result = ((personality_routine) &funcdesc)
- (_US_UNWIND_FRAME_STARTING, ucbp, (_Unwind_Context *) vrs);
- }
- #else
- pr_result = ((personality_routine) UCB_PR_ADDR (ucbp))
- (_US_UNWIND_FRAME_STARTING, ucbp, (_Unwind_Context *) vrs);
- #endif
- }
- while (pr_result == _URC_CONTINUE_UNWIND);
-
- if (pr_result != _URC_INSTALL_CONTEXT)
- abort();
- #if __FDPIC__
- /* r9 could have been lost due to PLT jump. Restore correct value. */
- vrs->core.r[FDPIC_REGNUM] = _Unwind_gnu_Find_got (VRS_PC (vrs));
- #endif
- uw_restore_core_regs (vrs, &vrs->core);
- }
- /* Perform phase2 forced unwinding. */
- static _Unwind_Reason_Code
- unwind_phase2_forced (_Unwind_Control_Block *ucbp, phase2_vrs *entry_vrs,
- int resuming)
- {
- _Unwind_Stop_Fn stop_fn = (_Unwind_Stop_Fn) UCB_FORCED_STOP_FN (ucbp);
- void *stop_arg = (void *)UCB_FORCED_STOP_ARG (ucbp);
- _Unwind_Reason_Code pr_result = 0;
- /* We use phase1_vrs here even though we do not demand save, for the
- prev_sp field. */
- phase1_vrs saved_vrs, next_vrs;
- /* Save the core registers. */
- saved_vrs.core = entry_vrs->core;
- /* We don't need to demand-save the non-core registers, because we
- unwind in a single pass. */
- saved_vrs.demand_save_flags = 0;
- /* Unwind until we reach a propagation barrier. */
- do
- {
- _Unwind_State action;
- _Unwind_Reason_Code entry_code;
- _Unwind_Reason_Code stop_code;
- /* Find the entry for this routine. */
- entry_code = get_eit_entry (ucbp, VRS_PC (&saved_vrs));
- if (resuming)
- {
- action = _US_UNWIND_FRAME_RESUME | _US_FORCE_UNWIND;
- resuming = 0;
- }
- else
- action = _US_UNWIND_FRAME_STARTING | _US_FORCE_UNWIND;
- if (entry_code == _URC_OK)
- {
- UCB_SAVED_CALLSITE_ADDR (ucbp) = VRS_PC (&saved_vrs);
- next_vrs = saved_vrs;
- /* Call the pr to decide what to do. */
- #if __FDPIC__
- {
- volatile struct funcdesc_t funcdesc;
- funcdesc.ptr = UCB_PR_ADDR (ucbp);
- funcdesc.got = UCB_PR_GOT (ucbp);
- pr_result = ((personality_routine) &funcdesc)
- (action, ucbp, (void *) &next_vrs);
- }
- #else
- pr_result = ((personality_routine) UCB_PR_ADDR (ucbp))
- (action, ucbp, (void *) &next_vrs);
- #endif
- saved_vrs.prev_sp = VRS_SP (&next_vrs);
- }
- else
- {
- /* Treat any failure as the end of unwinding, to cope more
- gracefully with missing EH information. Mixed EH and
- non-EH within one object will usually result in failure,
- because the .ARM.exidx tables do not indicate the end
- of the code to which they apply; but mixed EH and non-EH
- shared objects should return an unwind failure at the
- entry of a non-EH shared object. */
- action |= _US_END_OF_STACK;
- saved_vrs.prev_sp = VRS_SP (&saved_vrs);
- }
- stop_code = stop_fn (1, action, ucbp->exception_class, ucbp,
- (void *)&saved_vrs, stop_arg);
- if (stop_code != _URC_NO_REASON)
- return _URC_FAILURE;
- if (entry_code != _URC_OK)
- return entry_code;
- saved_vrs = next_vrs;
- }
- while (pr_result == _URC_CONTINUE_UNWIND);
- if (pr_result != _URC_INSTALL_CONTEXT)
- {
- /* Some sort of failure has occurred in the pr and probably the
- pr returned _URC_FAILURE. */
- return _URC_FAILURE;
- }
- #if __FDPIC__
- /* r9 could have been lost due to PLT jump. Restore correct value. */
- saved_vrs.core.r[FDPIC_REGNUM] = _Unwind_gnu_Find_got (VRS_PC (&saved_vrs));
- #endif
- uw_restore_core_regs (&saved_vrs, &saved_vrs.core);
- }
- /* This is a very limited implementation of _Unwind_GetCFA. It returns
- the stack pointer as it is about to be unwound, and is only valid
- while calling the stop function during forced unwinding. If the
- current personality routine result is going to run a cleanup, this
- will not be the CFA; but when the frame is really unwound, it will
- be. */
- _Unwind_Word
- _Unwind_GetCFA (_Unwind_Context *context)
- {
- return ((phase1_vrs *) context)->prev_sp;
- }
- /* Perform phase1 unwinding. UCBP is the exception being thrown, and
- entry_VRS is the register state on entry to _Unwind_RaiseException. */
- _Unwind_Reason_Code
- __gnu_Unwind_RaiseException (_Unwind_Control_Block *, phase2_vrs *);
- _Unwind_Reason_Code
- __gnu_Unwind_RaiseException (_Unwind_Control_Block * ucbp,
- phase2_vrs * entry_vrs)
- {
- phase1_vrs saved_vrs;
- _Unwind_Reason_Code pr_result;
- /* Set the pc to the call site. */
- VRS_PC (entry_vrs) = VRS_RETURN(entry_vrs);
- /* Save the core registers. */
- saved_vrs.core = entry_vrs->core;
- /* Set demand-save flags. */
- saved_vrs.demand_save_flags = ~(_uw) 0;
-
- /* Unwind until we reach a propagation barrier. */
- do
- {
- /* Find the entry for this routine. */
- if (get_eit_entry (ucbp, VRS_PC (&saved_vrs)) != _URC_OK)
- return _URC_FAILURE;
- /* Call the pr to decide what to do. */
- #if __FDPIC__
- {
- volatile struct funcdesc_t funcdesc;
- funcdesc.ptr = UCB_PR_ADDR (ucbp);
- funcdesc.got = UCB_PR_GOT (ucbp);
- pr_result = ((personality_routine) &funcdesc)
- (_US_VIRTUAL_UNWIND_FRAME, ucbp, (void *) &saved_vrs);
- }
- #else
- pr_result = ((personality_routine) UCB_PR_ADDR (ucbp))
- (_US_VIRTUAL_UNWIND_FRAME, ucbp, (void *) &saved_vrs);
- #endif
- }
- while (pr_result == _URC_CONTINUE_UNWIND);
- /* We've unwound as far as we want to go, so restore the original
- register state. */
- restore_non_core_regs (&saved_vrs);
- if (pr_result != _URC_HANDLER_FOUND)
- {
- /* Some sort of failure has occurred in the pr and probably the
- pr returned _URC_FAILURE. */
- return _URC_FAILURE;
- }
-
- unwind_phase2 (ucbp, entry_vrs);
- }
- /* Resume unwinding after a cleanup has been run. UCBP is the exception
- being thrown and ENTRY_VRS is the register state on entry to
- _Unwind_Resume. */
- _Unwind_Reason_Code
- __gnu_Unwind_ForcedUnwind (_Unwind_Control_Block *,
- _Unwind_Stop_Fn, void *, phase2_vrs *);
- _Unwind_Reason_Code
- __gnu_Unwind_ForcedUnwind (_Unwind_Control_Block *ucbp,
- _Unwind_Stop_Fn stop_fn, void *stop_arg,
- phase2_vrs *entry_vrs)
- {
- UCB_FORCED_STOP_FN (ucbp) = (_uw) stop_fn;
- UCB_FORCED_STOP_ARG (ucbp) = (_uw) stop_arg;
- /* Set the pc to the call site. */
- VRS_PC (entry_vrs) = VRS_RETURN(entry_vrs);
- return unwind_phase2_forced (ucbp, entry_vrs, 0);
- }
- _Unwind_Reason_Code
- __gnu_Unwind_Resume (_Unwind_Control_Block *, phase2_vrs *);
- _Unwind_Reason_Code
- __gnu_Unwind_Resume (_Unwind_Control_Block * ucbp, phase2_vrs * entry_vrs)
- {
- _Unwind_Reason_Code pr_result;
- /* Recover the saved address. */
- VRS_PC (entry_vrs) = UCB_SAVED_CALLSITE_ADDR (ucbp);
- if (UCB_FORCED_STOP_FN (ucbp))
- {
- unwind_phase2_forced (ucbp, entry_vrs, 1);
- /* We can't return failure at this point. */
- abort ();
- }
- /* Call the cached PR. */
- #if __FDPIC__
- {
- volatile struct funcdesc_t funcdesc;
- funcdesc.ptr = UCB_PR_ADDR (ucbp);
- funcdesc.got = UCB_PR_GOT (ucbp);
- pr_result = ((personality_routine) &funcdesc)
- (_US_UNWIND_FRAME_RESUME, ucbp, (_Unwind_Context *) entry_vrs);
- }
- #else
- pr_result = ((personality_routine) UCB_PR_ADDR (ucbp))
- (_US_UNWIND_FRAME_RESUME, ucbp, (_Unwind_Context *) entry_vrs);
- #endif
- switch (pr_result)
- {
- case _URC_INSTALL_CONTEXT:
- /* Upload the registers to enter the landing pad. */
- #if __FDPIC__
- /* r9 could have been lost due to PLT jump. Restore correct value. */
- entry_vrs->core.r[FDPIC_REGNUM] = _Unwind_gnu_Find_got (VRS_PC (entry_vrs));
- #endif
- uw_restore_core_regs (entry_vrs, &entry_vrs->core);
- case _URC_CONTINUE_UNWIND:
- /* Continue unwinding the next frame. */
- unwind_phase2 (ucbp, entry_vrs);
- default:
- abort ();
- }
- }
- _Unwind_Reason_Code
- __gnu_Unwind_Resume_or_Rethrow (_Unwind_Control_Block *, phase2_vrs *);
- _Unwind_Reason_Code
- __gnu_Unwind_Resume_or_Rethrow (_Unwind_Control_Block * ucbp,
- phase2_vrs * entry_vrs)
- {
- if (!UCB_FORCED_STOP_FN (ucbp))
- return __gnu_Unwind_RaiseException (ucbp, entry_vrs);
- /* Set the pc to the call site. */
- VRS_PC (entry_vrs) = VRS_RETURN (entry_vrs);
- /* Continue unwinding the next frame. */
- return unwind_phase2_forced (ucbp, entry_vrs, 0);
- }
- /* Clean up an exception object when unwinding is complete. */
- void
- _Unwind_Complete (_Unwind_Control_Block * ucbp __attribute__((unused)))
- {
- }
- /* Free an exception. */
- void
- _Unwind_DeleteException (_Unwind_Exception * exc)
- {
- if (exc->exception_cleanup)
- (*exc->exception_cleanup) (_URC_FOREIGN_EXCEPTION_CAUGHT, exc);
- }
- /* Perform stack backtrace through unwind data. */
- _Unwind_Reason_Code
- __gnu_Unwind_Backtrace(_Unwind_Trace_Fn trace, void * trace_argument,
- phase2_vrs * entry_vrs);
- _Unwind_Reason_Code
- __gnu_Unwind_Backtrace(_Unwind_Trace_Fn trace, void * trace_argument,
- phase2_vrs * entry_vrs)
- {
- phase1_vrs saved_vrs;
- _Unwind_Reason_Code code;
- _Unwind_Control_Block ucb;
- _Unwind_Control_Block *ucbp = &ucb;
- /* Set the pc to the call site. */
- VRS_PC (entry_vrs) = VRS_RETURN (entry_vrs);
- /* Save the core registers. */
- saved_vrs.core = entry_vrs->core;
- /* Set demand-save flags. */
- saved_vrs.demand_save_flags = ~(_uw) 0;
-
- do
- {
- /* Find the entry for this routine. */
- if (get_eit_entry (ucbp, VRS_PC (&saved_vrs)) != _URC_OK)
- {
- code = _URC_FAILURE;
- break;
- }
- /* The dwarf unwinder assumes the context structure holds things
- like the function and LSDA pointers. The ARM implementation
- caches these in the exception header (UCB). To avoid
- rewriting everything we make the virtual IP register point at
- the UCB. */
- _Unwind_SetGR((_Unwind_Context *)&saved_vrs, UNWIND_POINTER_REG, (_Unwind_Ptr) ucbp);
- /* Call trace function. */
- if ((*trace) ((_Unwind_Context *) &saved_vrs, trace_argument)
- != _URC_NO_REASON)
- {
- code = _URC_FAILURE;
- break;
- }
- /* Call the pr to decide what to do. */
- #if __FDPIC__
- {
- volatile struct funcdesc_t funcdesc;
- funcdesc.ptr = UCB_PR_ADDR (ucbp);
- funcdesc.got = UCB_PR_GOT (ucbp);
- code = ((personality_routine) &funcdesc)
- (_US_VIRTUAL_UNWIND_FRAME | _US_FORCE_UNWIND,
- ucbp, (void *) &saved_vrs);
- }
- #else
- code = ((personality_routine) UCB_PR_ADDR (ucbp))
- (_US_VIRTUAL_UNWIND_FRAME | _US_FORCE_UNWIND,
- ucbp, (void *) &saved_vrs);
- #endif
- }
- while (code != _URC_END_OF_STACK
- && code != _URC_FAILURE);
- restore_non_core_regs (&saved_vrs);
- return code;
- }
- /* Common implementation for ARM ABI defined personality routines.
- ID is the index of the personality routine, other arguments are as defined
- by __aeabi_unwind_cpp_pr{0,1,2}. */
- static _Unwind_Reason_Code
- __gnu_unwind_pr_common (_Unwind_State state,
- _Unwind_Control_Block *ucbp,
- _Unwind_Context *context,
- int id)
- {
- __gnu_unwind_state uws;
- _uw *data;
- _uw offset;
- _uw len;
- _uw rtti_count;
- int phase2_call_unexpected_after_unwind = 0;
- int in_range = 0;
- int forced_unwind = state & _US_FORCE_UNWIND;
- state &= _US_ACTION_MASK;
- data = (_uw *) ucbp->pr_cache.ehtp;
- uws.data = *(data++);
- uws.next = data;
- if (id == 0)
- {
- uws.data <<= 8;
- uws.words_left = 0;
- uws.bytes_left = 3;
- }
- else if (id < 3)
- {
- uws.words_left = (uws.data >> 16) & 0xff;
- uws.data <<= 16;
- uws.bytes_left = 2;
- data += uws.words_left;
- }
- /* Restore the saved pointer. */
- if (state == _US_UNWIND_FRAME_RESUME)
- data = (_uw *) ucbp->cleanup_cache.bitpattern[0];
- if ((ucbp->pr_cache.additional & 1) == 0)
- {
- /* Process descriptors. */
- while (*data)
- {
- _uw addr;
- _uw fnstart;
- if (id == 2)
- {
- len = ((EHT32 *) data)->length;
- offset = ((EHT32 *) data)->offset;
- data += 2;
- }
- else
- {
- len = ((EHT16 *) data)->length;
- offset = ((EHT16 *) data)->offset;
- data++;
- }
- fnstart = ucbp->pr_cache.fnstart + (offset & ~1);
- addr = _Unwind_GetGR (context, R_PC);
- in_range = (fnstart <= addr && addr < fnstart + (len & ~1));
- switch (((offset & 1) << 1) | (len & 1))
- {
- case 0:
- /* Cleanup. */
- if (state != _US_VIRTUAL_UNWIND_FRAME
- && in_range)
- {
- /* Cleanup in range, and we are running cleanups. */
- _uw lp;
- /* Landing pad address is 31-bit pc-relative offset. */
- lp = selfrel_offset31 (data);
- data++;
- /* Save the exception data pointer. */
- ucbp->cleanup_cache.bitpattern[0] = (_uw) data;
- if (!__cxa_begin_cleanup (ucbp))
- return _URC_FAILURE;
- /* Setup the VRS to enter the landing pad. */
- _Unwind_SetGR (context, R_PC, lp);
- return _URC_INSTALL_CONTEXT;
- }
- /* Cleanup not in range, or we are in stage 1. */
- data++;
- break;
- case 1:
- /* Catch handler. */
- if (state == _US_VIRTUAL_UNWIND_FRAME)
- {
- if (in_range)
- {
- /* Check for a barrier. */
- _uw rtti;
- bool is_reference = (data[0] & uint32_highbit) != 0;
- void *matched;
- enum __cxa_type_match_result match_type;
- /* Check for no-throw areas. */
- if (data[1] == (_uw) -2)
- return _URC_FAILURE;
- /* The thrown object immediately follows the ECB. */
- matched = (void *)(ucbp + 1);
- if (data[1] != (_uw) -1)
- {
- /* Match a catch specification. */
- rtti = _Unwind_decode_typeinfo_ptr (0,
- (_uw) &data[1]);
- match_type = __cxa_type_match (ucbp,
- (type_info *) rtti,
- is_reference,
- &matched);
- }
- else
- match_type = ctm_succeeded;
- if (match_type)
- {
- ucbp->barrier_cache.sp =
- _Unwind_GetGR (context, R_SP);
- // ctm_succeeded_with_ptr_to_base really
- // means _c_t_m indirected the pointer
- // object. We have to reconstruct the
- // additional pointer layer by using a temporary.
- if (match_type == ctm_succeeded_with_ptr_to_base)
- {
- ucbp->barrier_cache.bitpattern[2]
- = (_uw) matched;
- ucbp->barrier_cache.bitpattern[0]
- = (_uw) &ucbp->barrier_cache.bitpattern[2];
- }
- else
- ucbp->barrier_cache.bitpattern[0] = (_uw) matched;
- ucbp->barrier_cache.bitpattern[1] = (_uw) data;
- return _URC_HANDLER_FOUND;
- }
- }
- /* Handler out of range, or not matched. */
- }
- else if (ucbp->barrier_cache.sp == _Unwind_GetGR (context, R_SP)
- && ucbp->barrier_cache.bitpattern[1] == (_uw) data)
- {
- /* Matched a previous propagation barrier. */
- _uw lp;
- /* Setup for entry to the handler. */
- lp = selfrel_offset31 (data);
- _Unwind_SetGR (context, R_PC, lp);
- _Unwind_SetGR (context, 0, (_uw) ucbp);
- return _URC_INSTALL_CONTEXT;
- }
- /* Catch handler not matched. Advance to the next descriptor. */
- data += 2;
- break;
- case 2:
- rtti_count = data[0] & 0x7fffffff;
- /* Exception specification. */
- if (state == _US_VIRTUAL_UNWIND_FRAME)
- {
- if (in_range && (!forced_unwind || !rtti_count))
- {
- /* Match against the exception specification. */
- _uw i;
- _uw rtti;
- void *matched;
- for (i = 0; i < rtti_count; i++)
- {
- matched = (void *)(ucbp + 1);
- rtti = _Unwind_decode_typeinfo_ptr (0,
- (_uw) &data[i + 1]);
- if (__cxa_type_match (ucbp, (type_info *) rtti, 0,
- &matched))
- break;
- }
- if (i == rtti_count)
- {
- /* Exception does not match the spec. */
- ucbp->barrier_cache.sp =
- _Unwind_GetGR (context, R_SP);
- ucbp->barrier_cache.bitpattern[0] = (_uw) matched;
- ucbp->barrier_cache.bitpattern[1] = (_uw) data;
- return _URC_HANDLER_FOUND;
- }
- }
- /* Handler out of range, or exception is permitted. */
- }
- else if (ucbp->barrier_cache.sp == _Unwind_GetGR (context, R_SP)
- && ucbp->barrier_cache.bitpattern[1] == (_uw) data)
- {
- /* Matched a previous propagation barrier. */
- _uw lp;
- /* Record the RTTI list for __cxa_call_unexpected. */
- ucbp->barrier_cache.bitpattern[1] = rtti_count;
- ucbp->barrier_cache.bitpattern[2] = 0;
- ucbp->barrier_cache.bitpattern[3] = 4;
- ucbp->barrier_cache.bitpattern[4] = (_uw) &data[1];
- if (data[0] & uint32_highbit)
- {
- data += rtti_count + 1;
- /* Setup for entry to the handler. */
- lp = selfrel_offset31 (data);
- data++;
- _Unwind_SetGR (context, R_PC, lp);
- _Unwind_SetGR (context, 0, (_uw) ucbp);
- return _URC_INSTALL_CONTEXT;
- }
- else
- phase2_call_unexpected_after_unwind = 1;
- }
- if (data[0] & uint32_highbit)
- data++;
- data += rtti_count + 1;
- break;
- default:
- /* Should never happen. */
- return _URC_FAILURE;
- }
- /* Finished processing this descriptor. */
- }
- }
- if (id >= 3)
- {
- /* 24-bit ecoding */
- if (__gnu_unwind_24bit (context, uws.data, id == 4) != _URC_OK)
- return _URC_FAILURE;
- }
- else
- {
- if (__gnu_unwind_execute (context, &uws) != _URC_OK)
- return _URC_FAILURE;
- }
-
- if (phase2_call_unexpected_after_unwind)
- {
- /* Enter __cxa_unexpected as if called from the call site. */
- _Unwind_SetGR (context, R_LR, _Unwind_GetGR (context, R_PC));
- _Unwind_SetGR (context, R_PC, (_uw) &__cxa_call_unexpected);
- return _URC_INSTALL_CONTEXT;
- }
- return _URC_CONTINUE_UNWIND;
- }
|