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       1                 :             : /* Populate process registers from a linux perf_events sample.
       2                 :             :    Copyright (C) 2026 Matt Turner
       3                 :             :    This file is part of elfutils.
       4                 :             : 
       5                 :             :    This file is free software; you can redistribute it and/or modify
       6                 :             :    it under the terms of either
       7                 :             : 
       8                 :             :      * the GNU Lesser General Public License as published by the Free
       9                 :             :        Software Foundation; either version 3 of the License, or (at
      10                 :             :        your option) any later version
      11                 :             : 
      12                 :             :    or
      13                 :             : 
      14                 :             :      * the GNU General Public License as published by the Free
      15                 :             :        Software Foundation; either version 2 of the License, or (at
      16                 :             :        your option) any later version
      17                 :             : 
      18                 :             :    or both in parallel, as here.
      19                 :             : 
      20                 :             :    elfutils is distributed in the hope that it will be useful, but
      21                 :             :    WITHOUT ANY WARRANTY; without even the implied warranty of
      22                 :             :    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      23                 :             :    General Public License for more details.
      24                 :             : 
      25                 :             :    You should have received copies of the GNU General Public License and
      26                 :             :    the GNU Lesser General Public License along with this program.  If
      27                 :             :    not, see <http://www.gnu.org/licenses/>.  */
      28                 :             : 
      29                 :             : 
      30                 :             : #ifdef HAVE_CONFIG_H
      31                 :             : # include <config.h>
      32                 :             : #endif
      33                 :             : 
      34                 :             : #define BACKEND alpha_
      35                 :             : #include "libebl_CPU.h"
      36                 :             : #include "libebl_PERF_FLAGS.h"
      37                 :             : 
      38                 :             : /* The default sample_perf_regs_mapping maps perf register numbers 1:1,
      39                 :             :    which gives the DWARF number for $0-$30.  PERF_REG_ALPHA_PC is 31,
      40                 :             :    which cannot be mistaken for $31 since the kernel does not sample
      41                 :             :    the zero register.  */
      42                 :             : #define SAMPLE_PC 31
      43                 :             : 
      44                 :             : bool
      45                 :           0 : alpha_sample_sp_pc (const Dwarf_Word *regs, uint32_t n_regs,
      46                 :             :                     const int *regs_mapping, size_t n_regs_mapping,
      47                 :             :                     Dwarf_Word *sp, Dwarf_Word *pc)
      48                 :             : {
      49                 :           0 :   return generic_sample_sp_pc (regs, n_regs, regs_mapping, n_regs_mapping,
      50                 :             :                                sp, 30 /* index of sp in dwarf_regs */,
      51                 :             :                                pc, SAMPLE_PC);
      52                 :             : }
      53                 :             : 
      54                 :             : bool
      55                 :           0 : alpha_set_initial_registers_sample (const Dwarf_Word *regs, uint32_t n_regs,
      56                 :             :                                     const int *regs_mapping, size_t n_regs_mapping,
      57                 :             :                                     ebl_tid_registers_t *setfunc,
      58                 :             :                                     void *arg)
      59                 :             : {
      60                 :           0 :   Dwarf_Word dwarf_regs[32] = { 0 };
      61   [ #  #  #  # ]:           0 :   for (size_t i = 0; i < n_regs && i < n_regs_mapping; i++)
      62         [ #  # ]:           0 :     if (regs_mapping[i] >= 0 && regs_mapping[i] < 32)
      63                 :           0 :       dwarf_regs[regs_mapping[i]] = regs[i];
      64                 :             : 
      65                 :           0 :   Dwarf_Word pc = dwarf_regs[SAMPLE_PC];
      66                 :           0 :   dwarf_regs[31] = 0;
      67                 :             : 
      68                 :             :   /* The kernel cannot sample the callee-saved $9-$15.  Leave them
      69                 :             :      unset so that the unwinder does not use a bogus value.  */
      70                 :           0 :   return (setfunc (0, 9, &dwarf_regs[0], arg)
      71         [ #  # ]:           0 :           && setfunc (16, 16, &dwarf_regs[16], arg)
      72   [ #  #  #  # ]:           0 :           && setfunc (-1, 1, &pc, arg));
      73                 :             : }