Coverage Report

Created: 2024-05-21 06:29

/src/binutils-gdb/opcodes/bpf-dis.c
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Source (jump to first uncovered line)
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/* bpf-dis.c - BPF disassembler.
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   Copyright (C) 2023-2024 Free Software Foundation, Inc.
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   Contributed by Oracle Inc.
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   This file is part of the GNU binutils.
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   This is free software; you can redistribute them and/or modify them
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   under the terms of the GNU General Public License as published by
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   the Free Software Foundation; either version 3, or (at your option)
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   any later version.
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   This program is distributed in the hope that it will be useful, but
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   WITHOUT ANY WARRANTY; without even the implied warranty of
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   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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   General Public License for more details.
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   You should have received a copy of the GNU General Public License
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   along with this program; see the file COPYING3. If not,
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   see <http://www.gnu.org/licenses/>.  */
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#include "sysdep.h"
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#include "disassemble.h"
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#include "libiberty.h"
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#include "opintl.h"
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#include "opcode/bpf.h"
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#include "elf-bfd.h"
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#include "elf/bpf.h"
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#include <string.h>
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#include <inttypes.h>
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/* This disassembler supports two different syntaxes for BPF assembly.
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   One is called "normal" and has the typical form for assembly
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   languages, with mnemonics and the like.  The other is called
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   "pseudoc" and looks like C.  */
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enum bpf_dialect
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{
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  BPF_DIALECT_NORMAL,
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  BPF_DIALECT_PSEUDOC
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};
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/* Global configuration for the disassembler.  */
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static enum bpf_dialect asm_dialect = BPF_DIALECT_NORMAL;
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static int asm_bpf_version = -1;
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static int asm_obase = 10;
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/* Print BPF specific command-line options.  */
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52
void
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print_bpf_disassembler_options (FILE *stream)
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0
{
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0
  fprintf (stream, _("\n\
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0
The following BPF specific disassembler options are supported for use\n\
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0
with the -M switch (multiple options should be separated by commas):\n"));
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0
  fprintf (stream, "\n");
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0
  fprintf (stream, _("\
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0
      pseudoc                  Use pseudo-c syntax.\n\
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0
      v1,v2,v3,v4,xbpf         Version of the BPF ISA to use.\n\
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0
      hex,oct,dec              Output numerical base for immediates.\n"));
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0
}
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/* Parse BPF specific command-line options.  */
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static void
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parse_bpf_dis_option (const char *option)
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0
{
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0
  if (strcmp (option, "pseudoc") == 0)
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0
    asm_dialect = BPF_DIALECT_PSEUDOC;
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0
  else if (strcmp (option, "v1") == 0)
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0
    asm_bpf_version = BPF_V1;
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0
  else if (strcmp (option, "v2") == 0)
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0
    asm_bpf_version = BPF_V2;
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0
  else if (strcmp (option, "v3") == 0)
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0
    asm_bpf_version = BPF_V3;
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0
  else if (strcmp (option, "v4") == 0)
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0
    asm_bpf_version = BPF_V4;
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0
  else if (strcmp (option, "xbpf") == 0)
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0
    asm_bpf_version = BPF_XBPF;
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0
  else if (strcmp (option, "hex") == 0)
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0
    asm_obase = 16;
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0
  else if (strcmp (option, "oct") == 0)
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0
    asm_obase = 8;
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0
  else if (strcmp (option, "dec") == 0)
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0
    asm_obase = 10;
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0
  else
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    /* xgettext:c-format */
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0
    opcodes_error_handler (_("unrecognized disassembler option: %s"), option);
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0
}
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static void
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parse_bpf_dis_options (const char *opts_in)
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0
{
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0
  char *opts = xstrdup (opts_in), *opt = opts, *opt_end = opts;
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0
  for ( ; opt_end != NULL; opt = opt_end + 1)
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0
    {
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0
      if ((opt_end = strchr (opt, ',')) != NULL)
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0
  *opt_end = 0;
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0
      parse_bpf_dis_option (opt);
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0
    }
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0
  free (opts);
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0
}
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/* Auxiliary function used in print_insn_bpf below.  */
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static void
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print_register (disassemble_info *info,
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                const char *tag, uint8_t regno)
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1.33k
{
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1.33k
  const char *fmt
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1.33k
    = (asm_dialect == BPF_DIALECT_NORMAL
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1.33k
       ? "%%r%d"
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1.33k
       : ((*(tag + 2) == 'w')
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0
          ? "w%d"
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0
          : "r%d"));
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1.33k
  (*info->fprintf_styled_func) (info->stream, dis_style_register, fmt, regno);
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1.33k
}
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/* Main entry point.
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   Print one instruction from PC on INFO->STREAM.
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   Return the size of the instruction (in bytes).  */
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int
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print_insn_bpf (bfd_vma pc, disassemble_info *info)
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4.24k
{
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4.24k
  int insn_size = 8, status;
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4.24k
  bfd_byte insn_bytes[16];
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4.24k
  bpf_insn_word word = 0;
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4.24k
  const struct bpf_opcode *insn = NULL;
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4.24k
  enum bpf_endian endian = (info->endian == BFD_ENDIAN_LITTLE
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4.24k
                            ? BPF_ENDIAN_LITTLE : BPF_ENDIAN_BIG);
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  /* Handle bpf-specific command-line options.  */
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4.24k
  if (info->disassembler_options != NULL)
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0
    {
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0
      parse_bpf_dis_options (info->disassembler_options);
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      /* Avoid repeteadly parsing the options.  */
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0
      info->disassembler_options = NULL;
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0
    }
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  /* Determine what version of the BPF ISA to use when disassembling.
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     If the user didn't explicitly specify an ISA version, then derive
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     it from the CPU Version flag in the ELF header.  A CPU version of
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     0 in the header means "latest version".  */
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4.24k
  if (asm_bpf_version == -1 && info->section && info->section->owner)
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1
    {
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1
      struct bfd *abfd = info->section->owner;
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1
      Elf_Internal_Ehdr *header = elf_elfheader (abfd);
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1
      int cpu_version = header->e_flags & EF_BPF_CPUVER;
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1
      switch (cpu_version)
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1
        {
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1
        case 0: asm_bpf_version = BPF_V4; break;
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0
        case 1: asm_bpf_version = BPF_V1; break;
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0
        case 2: asm_bpf_version = BPF_V2; break;
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0
        case 3: asm_bpf_version = BPF_V3; break;
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0
        case 4: asm_bpf_version = BPF_V4; break;
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0
        case 0xf: asm_bpf_version = BPF_XBPF; break;
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0
        default:
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          /* xgettext:c-format */
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0
          opcodes_error_handler (_("unknown BPF CPU version %u\n"),
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0
                                 cpu_version);
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0
          break;
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1
        }
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1
    }
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  /* Print eight bytes per line.  */
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4.24k
  info->bytes_per_chunk = 1;
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4.24k
  info->bytes_per_line = 8;
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  /* Read an instruction word.  */
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4.24k
  status = (*info->read_memory_func) (pc, insn_bytes, 8, info);
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4.24k
  if (status != 0)
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141
    {
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141
      (*info->memory_error_func) (status, pc, info);
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141
      return -1;
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141
    }
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4.10k
  word = (bpf_insn_word) bfd_getb64 (insn_bytes);
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  /* Try to match an instruction with it.  */
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4.10k
  insn = bpf_match_insn (word, endian, asm_bpf_version);
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  /* Print it out.  */
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4.10k
  if (insn)
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1.08k
    {
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1.08k
      const char *insn_tmpl
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1.08k
        = asm_dialect == BPF_DIALECT_NORMAL ? insn->normal : insn->pseudoc;
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1.08k
      const char *p = insn_tmpl;
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      /* Print the template contents completed with the instruction
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         operands.  */
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13.1k
      for (p = insn_tmpl; *p != '\0';)
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12.0k
        {
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12.0k
          switch (*p)
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12.0k
            {
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2.59k
            case ' ':
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              /* Single space prints to nothing.  */
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2.59k
              p += 1;
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2.59k
              break;
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3.48k
            case '%':
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3.48k
              if (*(p + 1) == '%')
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0
                {
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0
                  (*info->fprintf_styled_func) (info->stream, dis_style_text, "%%");
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0
                  p += 2;
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0
                }
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3.48k
              else if (*(p + 1) == 'w' || *(p + 1) == 'W')
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1.08k
                {
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                  /* %W prints to a single space.  */
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1.08k
                  (*info->fprintf_styled_func) (info->stream, dis_style_text, " ");
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1.08k
                  p += 2;
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1.08k
                }
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2.40k
              else if (strncmp (p, "%dr", 3) == 0)
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873
                {
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873
                  print_register (info, p, bpf_extract_dst (word, endian));
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873
                  p += 3;
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873
                }
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1.53k
              else if (strncmp (p, "%sr", 3) == 0)
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459
                {
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                  print_register (info, p, bpf_extract_src (word, endian));
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459
                  p += 3;
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459
                }
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1.07k
              else if (strncmp (p, "%dw", 3) == 0)
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0
                {
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0
                  print_register (info, p, bpf_extract_dst (word, endian));
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0
                  p += 3;
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0
                }
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1.07k
              else if (strncmp (p, "%sw", 3) == 0)
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0
                {
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0
                  print_register (info, p, bpf_extract_src (word, endian));
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0
                  p += 3;
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0
                }
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1.07k
              else if (strncmp (p, "%i32", 4) == 0
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1.07k
                       || strncmp (p, "%d32", 4) == 0
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1.07k
                       || strncmp (p, "%I32", 4) == 0)
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566
                {
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566
                  int32_t imm32 = bpf_extract_imm32 (word, endian);
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566
                  if (p[1] == 'I')
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0
                    (*info->fprintf_styled_func) (info->stream, dis_style_immediate,
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0
                                                  "%s",
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0
              asm_obase != 10 || imm32 >= 0 ? "+" : "");
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566
                  (*info->fprintf_styled_func) (info->stream, dis_style_immediate,
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566
                                                asm_obase == 10 ? "%" PRIi32
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566
                                                : asm_obase == 8 ? "%" PRIo32
250
0
                                                : "0x%" PRIx32,
251
566
                                                imm32);
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566
                  p += 4;
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566
                }
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505
              else if (strncmp (p, "%o16", 4) == 0
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505
                       || strncmp (p, "%d16", 4) == 0)
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496
                {
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496
                  int16_t offset16 = bpf_extract_offset16 (word, endian);
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259
496
                  if (p[1] == 'o')
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134
                    (*info->fprintf_styled_func) (info->stream, dis_style_immediate,
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134
                                                  "%s",
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134
              asm_obase != 10 || offset16 >= 0 ? "+" : "");
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496
                  if (asm_obase == 16 || asm_obase == 8)
264
0
                    (*info->fprintf_styled_func) (info->stream, dis_style_immediate,
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0
                                                  asm_obase == 8 ? "0%" PRIo16 : "0x%" PRIx16,
266
0
                                                  (uint16_t) offset16);
267
496
                  else
268
496
                    (*info->fprintf_styled_func) (info->stream, dis_style_immediate,
269
496
                                                  "%" PRIi16, offset16);
270
496
                  p += 4;
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496
                }
272
9
              else if (strncmp (p, "%i64", 4) == 0)
273
9
                {
274
9
                  bpf_insn_word word2 = 0;
275
276
9
                  status = (*info->read_memory_func) (pc + 8, insn_bytes + 8,
277
9
                                                          8, info);
278
9
                  if (status != 0)
279
0
                    {
280
0
                      (*info->memory_error_func) (status, pc + 8, info);
281
0
                      return -1;
282
0
                    }
283
9
                  word2 = (bpf_insn_word) bfd_getb64 (insn_bytes + 8);
284
285
9
                  (*info->fprintf_styled_func) (info->stream, dis_style_immediate,
286
9
                                                asm_obase == 10 ? "%" PRIi64
287
9
                                                : asm_obase == 8 ? "0%" PRIo64
288
0
                                                : "0x%" PRIx64,
289
9
                                                bpf_extract_imm64 (word, word2, endian));
290
9
                  insn_size = 16;
291
9
                  p += 4;
292
9
                }
293
0
              else
294
0
                {
295
                  /* xgettext:c-format */
296
0
                  opcodes_error_handler (_("# internal error, unknown tag in opcode template (%s)"),
297
0
                                         insn_tmpl);
298
0
                  return -1;
299
0
                }
300
3.48k
              break;
301
5.97k
            default:
302
              /* Any other character is printed literally.  */
303
5.97k
              (*info->fprintf_styled_func) (info->stream, dis_style_text, "%c", *p);
304
5.97k
              p += 1;
305
12.0k
            }
306
12.0k
        }
307
1.08k
    }
308
3.02k
  else
309
3.02k
    (*info->fprintf_styled_func) (info->stream, dis_style_text, "<unknown>");
310
311
4.10k
  return insn_size;
312
4.10k
}