| /* DWARF2 EH unwinding support for SPARC Solaris. |
| Copyright (C) 2009-2023 Free Software Foundation, Inc. |
| |
| This file is part of GCC. |
| |
| GCC is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 3, or (at your option) |
| any later version. |
| |
| GCC is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| GNU General Public License for more details. |
| |
| Under Section 7 of GPL version 3, you are granted additional |
| permissions described in the GCC Runtime Library Exception, version |
| 3.1, as published by the Free Software Foundation. |
| |
| You should have received a copy of the GNU General Public License and |
| a copy of the GCC Runtime Library Exception along with this program; |
| see the files COPYING3 and COPYING.RUNTIME respectively. If not, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| /* Do code reading to identify a signal frame, and set the frame |
| state data appropriately. See unwind-dw2.c for the structs. */ |
| |
| #include <ucontext.h> |
| #include <sys/frame.h> |
| #include <sys/stack.h> |
| |
| #ifdef __arch64__ |
| |
| #define IS_SIGHANDLER sparc64_is_sighandler |
| |
| static int |
| sparc64_is_sighandler (unsigned int *pc, void *cfa, int *nframes) |
| { |
| if (/* Solaris 8+ - multi-threaded |
| ---------------------------- |
| <__sighndlr>: save %sp, -176, %sp |
| <__sighndlr+4>: mov %i0, %o0 |
| <__sighndlr+8>: mov %i1, %o1 |
| <__sighndlr+12>: call %i3 |
| <__sighndlr+16>: mov %i2, %o2 |
| <__sighndlr+20>: ret <--- PC |
| <__sighndlr+24>: restore */ |
| pc[-5] == 0x9de3bf50 |
| && pc[-4] == 0x90100018 |
| && pc[-3] == 0x92100019 |
| && pc[-2] == 0x9fc6c000 |
| && pc[-1] == 0x9410001a |
| && pc[ 0] == 0x81c7e008 |
| && pc[ 1] == 0x81e80000) |
| { |
| /* We have observed different calling frames among different |
| versions of the operating system, so that we need to |
| discriminate using the upper frame. We look for the return |
| address of the caller frame (there is an offset of 15 double |
| words between the frame address and the place where this return |
| address is stored) in order to do some more pattern matching. */ |
| unsigned int cuh_pattern |
| = *(unsigned int *)(*(unsigned long *)(cfa + 15*8) - 4); |
| |
| if (cuh_pattern == 0x92100019) |
| /* This matches the call_user_handler pattern in Solaris 11 |
| libc.so.1: |
| |
| <call_user_handler+864>: mov %i1, %o1 |
| <call_user_handler+868>: call __sighndlr */ |
| *nframes = 3; |
| |
| return 1; |
| } |
| |
| return 0; |
| } |
| |
| #define MD_FALLBACK_FRAME_STATE_FOR sparc64_fallback_frame_state |
| |
| #define MD_FROB_UPDATE_CONTEXT sparc64_frob_update_context |
| |
| static void |
| sparc64_frob_update_context (struct _Unwind_Context *context, |
| _Unwind_FrameState *fs) |
| { |
| /* The column of %sp contains the old CFA, not the old value of %sp. |
| The CFA offset already comprises the stack bias so, when %sp is the |
| CFA register, we must avoid counting the stack bias twice. */ |
| if (fs->regs.cfa_reg == __builtin_dwarf_sp_column () |
| && fs->regs.cfa_how == CFA_REG_OFFSET |
| && fs->regs.cfa_offset != 0) |
| { |
| long i; |
| |
| context->cfa -= STACK_BIAS; |
| |
| for (i = 0; i < __LIBGCC_DWARF_FRAME_REGISTERS__ + 1; ++i) |
| if (fs->regs.how[i] == REG_SAVED_OFFSET) |
| _Unwind_SetGRPtr (context, i, |
| _Unwind_GetGRPtr (context, i) - STACK_BIAS); |
| } |
| } |
| |
| #else |
| |
| #define IS_SIGHANDLER sparc_is_sighandler |
| |
| static int |
| sparc_is_sighandler (unsigned int *pc, void *cfa, int *nframes) |
| { |
| if(/* Solaris 8+ - multi-threaded |
| ---------------------------- |
| <__sighndlr>: save %sp, -96, %sp |
| <__sighndlr+4>: mov %i0, %o0 |
| <__sighndlr+8>: mov %i1, %o1 |
| <__sighndlr+12>: call %i3 |
| <__sighndlr+16>: mov %i2, %o2 |
| <__sighndlr+20>: ret <--- PC |
| <__sighndlr+24>: restore */ |
| pc[-5] == 0x9de3bfa0 |
| && pc[-4] == 0x90100018 |
| && pc[-3] == 0x92100019 |
| && pc[-2] == 0x9fc6c000 |
| && pc[-1] == 0x9410001a |
| && pc[ 0] == 0x81c7e008 |
| && pc[ 1] == 0x81e80000) |
| { |
| /* We have observed different calling frames among different |
| versions of the operating system, so that we need to |
| discriminate using the upper frame. We look for the return |
| address of the caller frame (there is an offset of 15 words |
| between the frame address and the place where this return |
| address is stored) in order to do some more pattern matching. */ |
| unsigned int cuh_pattern |
| = *(unsigned int *)(*(unsigned int *)(cfa + 15*4) - 4); |
| |
| if (cuh_pattern == 0x92100019) |
| /* This matches the call_user_handler pattern in Solaris 11 |
| libc.so.1: |
| |
| <call_user_handler+876>: mov %i1, %o1 |
| <call_user_handler+880>: call __sighndlr */ |
| *nframes = 3; |
| |
| return 1; |
| } |
| |
| return 0; |
| } |
| |
| #define MD_FALLBACK_FRAME_STATE_FOR sparc_fallback_frame_state |
| |
| #endif |
| |
| static _Unwind_Reason_Code |
| MD_FALLBACK_FRAME_STATE_FOR (struct _Unwind_Context *context, |
| _Unwind_FrameState *fs) |
| { |
| void *pc = context->ra; |
| void *this_cfa = context->cfa; |
| int nframes = 0; |
| long new_cfa; |
| void *ra_location, *shifted_ra_location; |
| mcontext_t *mctx; |
| int i; |
| |
| /* Deal with frame-less function from which a signal was raised. */ |
| if (_Unwind_IsSignalFrame (context)) |
| { |
| /* The CFA is by definition unmodified in this case. */ |
| fs->regs.cfa_how = CFA_REG_OFFSET; |
| fs->regs.cfa_reg = __builtin_dwarf_sp_column (); |
| fs->regs.cfa_offset = 0; |
| |
| /* This is the canonical RA column. */ |
| fs->retaddr_column = 15; |
| |
| return _URC_NO_REASON; |
| } |
| |
| /* Do some pattern matching at the return address. */ |
| if (IS_SIGHANDLER (pc, this_cfa, &nframes)) |
| { |
| struct frame *fp = (struct frame *) this_cfa; |
| struct handler_args { |
| struct frame frwin; |
| ucontext_t ucontext; |
| } *handler_args; |
| ucontext_t *ucp; |
| |
| /* this_cfa points into the frame after the saved frame pointer and |
| saved pc (struct frame). |
| |
| The ucontext_t structure is in the kernel frame after a struct |
| frame. Since the frame sizes vary even within OS releases, we |
| need to walk the stack to get there. */ |
| for (i = 0; i < nframes; i++) |
| fp = (struct frame *) ((char *)fp->fr_savfp + STACK_BIAS); |
| |
| handler_args = (struct handler_args *) fp; |
| ucp = &handler_args->ucontext; |
| mctx = &ucp->uc_mcontext; |
| } |
| else |
| return _URC_END_OF_STACK; |
| |
| /* The frame address is %sp + STACK_BIAS in 64-bit mode. */ |
| new_cfa = mctx->gregs[REG_SP] + STACK_BIAS; |
| |
| fs->regs.cfa_how = CFA_REG_OFFSET; |
| fs->regs.cfa_reg = __builtin_dwarf_sp_column (); |
| fs->regs.cfa_offset = new_cfa - (long) this_cfa + STACK_BIAS; |
| |
| /* Restore global and out registers (in this order) from the |
| ucontext_t structure, uc_mcontext.gregs field. */ |
| for (i = 1; i < 16; i++) |
| { |
| /* We never restore %sp as everything is purely CFA-based. */ |
| if ((unsigned int) i == __builtin_dwarf_sp_column ()) |
| continue; |
| |
| /* First the global registers and then the out registers. */ |
| fs->regs.how[i] = REG_SAVED_OFFSET; |
| fs->regs.reg[i].loc.offset = (long)&mctx->gregs[REG_Y + i] - new_cfa; |
| } |
| |
| /* Just above the stack pointer there are 16 extended words in which |
| the register window (in and local registers) was saved. */ |
| for (i = 0; i < 16; i++) |
| { |
| fs->regs.how[i + 16] = REG_SAVED_OFFSET; |
| fs->regs.reg[i + 16].loc.offset = i * sizeof(long); |
| } |
| |
| /* Check whether we need to restore FPU registers. */ |
| if (mctx->fpregs.fpu_qcnt) |
| { |
| for (i = 0; i < 32; i++) |
| { |
| fs->regs.how[i + 32] = REG_SAVED_OFFSET; |
| fs->regs.reg[i + 32].loc.offset |
| = (long)&mctx->fpregs.fpu_fr.fpu_regs[i] - new_cfa; |
| } |
| |
| #ifdef __arch64__ |
| /* For 64-bit, fpu_fr.fpu_dregs contains 32 instead of 16 doubles. */ |
| for (i = 32; i < 64; i++) |
| { |
| if (i > 32 && (i & 1)) |
| continue; |
| |
| fs->regs.how[i + 32] = REG_SAVED_OFFSET; |
| fs->regs.reg[i + 32].loc.offset |
| = (long)&mctx->fpregs.fpu_fr.fpu_dregs[i/2] - new_cfa; |
| } |
| #endif |
| } |
| |
| /* State the rules to find the kernel's code "return address", which is |
| the address of the active instruction when the signal was caught. |
| On the SPARC, since RETURN_ADDR_OFFSET (essentially 8) is defined, we |
| need to preventively subtract it from the purported return address. */ |
| ra_location = &mctx->gregs[REG_PC]; |
| shifted_ra_location = &mctx->gregs[REG_Y]; |
| *(void **)shifted_ra_location = *(void **)ra_location - 8; |
| fs->retaddr_column = 0; |
| fs->regs.how[0] = REG_SAVED_OFFSET; |
| fs->regs.reg[0].loc.offset = (long)shifted_ra_location - new_cfa; |
| |
| /* SIGFPE for IEEE-754 exceptions is delivered after the faulting insn |
| rather than before it, so don't set fs->signal_frame in that case. |
| We test whether the cexc field of the FSR is zero. */ |
| if ((mctx->fpregs.fpu_fsr & 0x1f) == 0) |
| fs->signal_frame = 1; |
| |
| return _URC_NO_REASON; |
| } |
