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binutils-gdb/cpu/bpf.opc
Jose E. Marchesi ea195bb04c cpu: add eBPF cpu description
This patch adds a CPU description for the Linux kernel eBPF virtual
machine, plus supporting code for disassembler and assembler.

cpu/ChangeLog:

2019-05-23  Jose E. Marchesi  <jose.marchesi@oracle.com>

	* bpf.cpu: New file.
	* bpf.opc: Likewise.
2019-05-23 19:33:50 +02:00

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/* EBPF opcode support. -*- c -*-
Copyright (C) 2019 Free Software Foundation, Inc.
Contributed by Oracle, Inc.
This file is part of the GNU Binutils and of GDB.
This program 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 of the License, or
(at your option) any later version.
This program 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.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
MA 02110-1301, USA. */
/*
Each section is delimited with start and end markers.
<arch>-opc.h additions use: "-- opc.h"
<arch>-opc.c additions use: "-- opc.c"
<arch>-asm.c additions use: "-- asm.c"
<arch>-dis.c additions use: "-- dis.c"
<arch>-ibd.h additions use: "-- ibd.h". */
/* -- opc.h */
#undef CGEN_DIS_HASH_SIZE
#define CGEN_DIS_HASH_SIZE 1
#undef CGEN_DIS_HASH
#define CGEN_DIS_HASH(buffer, value) 0
/* Allows reason codes to be output when assembler errors occur. */
#define CGEN_VERBOSE_ASSEMBLER_ERRORS
#define CGEN_VALIDATE_INSN_SUPPORTED
extern int bpf_cgen_insn_supported (CGEN_CPU_DESC, const CGEN_INSN *);
/* -- opc.c */
/* -- asm.c */
/* Parse a signed 64-bit immediate. */
static const char *
parse_imm64 (CGEN_CPU_DESC cd,
const char **strp,
int opindex,
int64_t *valuep)
{
bfd_vma value;
enum cgen_parse_operand_result result;
const char *errmsg;
errmsg = (* cd->parse_operand_fn)
(cd, CGEN_PARSE_OPERAND_INTEGER, strp, opindex, BFD_RELOC_NONE,
&result, &value);
if (!errmsg)
*valuep = value;
return errmsg;
}
/* Endianness size operands are integer immediates whose values can be
16, 32 or 64. */
static const char *
parse_endsize (CGEN_CPU_DESC cd,
const char **strp,
int opindex,
unsigned long *valuep)
{
const char *errmsg;
errmsg = cgen_parse_unsigned_integer (cd, strp, opindex, valuep);
if (errmsg)
return errmsg;
switch (*valuep)
{
case 16:
case 32:
case 64:
break;
default:
return _("expected 16, 32 or 64 in");
}
return NULL;
}
/* Special check to ensure that the right instruction variant is used
for the given endianness induced by the ISA selected in the CPU.
See bpf.cpu for a discussion on how eBPF is really two instruction
sets. */
int
bpf_cgen_insn_supported (CGEN_CPU_DESC cd, const CGEN_INSN *insn)
{
CGEN_BITSET isas = CGEN_INSN_BITSET_ATTR_VALUE (insn, CGEN_INSN_ISA);
return cgen_bitset_intersect_p (&isas, cd->isas);
}
/* -- dis.c */
/* We need to customize the disassembler a bit:
- Use 8 bytes per line by default.
*/
#define CGEN_PRINT_INSN bpf_print_insn
static int
bpf_print_insn (CGEN_CPU_DESC cd, bfd_vma pc, disassemble_info *info)
{
bfd_byte buf[CGEN_MAX_INSN_SIZE];
int buflen;
int status;
info->bytes_per_chunk = 1;
info->bytes_per_line = 8;
/* Attempt to read the base part of the insn. */
buflen = cd->base_insn_bitsize / 8;
status = (*info->read_memory_func) (pc, buf, buflen, info);
/* Try again with the minimum part, if min < base. */
if (status != 0 && (cd->min_insn_bitsize < cd->base_insn_bitsize))
{
buflen = cd->min_insn_bitsize / 8;
status = (*info->read_memory_func) (pc, buf, buflen, info);
}
if (status != 0)
{
(*info->memory_error_func) (status, pc, info);
return -1;
}
return print_insn (cd, pc, info, buf, buflen);
}
/* Signed immediates should be printed in hexadecimal. */
static void
print_immediate (CGEN_CPU_DESC cd ATTRIBUTE_UNUSED,
void *dis_info,
int64_t value,
unsigned int attrs ATTRIBUTE_UNUSED,
bfd_vma pc ATTRIBUTE_UNUSED,
int length ATTRIBUTE_UNUSED)
{
disassemble_info *info = (disassemble_info *) dis_info;
if (value <= 9)
(*info->fprintf_func) (info->stream, "%" PRId64, value);
else
(*info->fprintf_func) (info->stream, "%#" PRIx64, value);
/* This is to avoid -Wunused-function for print_normal. */
if (0)
print_normal (cd, dis_info, value, attrs, pc, length);
}
/* Endianness bit sizes should be printed in decimal. */
static void
print_endsize (CGEN_CPU_DESC cd ATTRIBUTE_UNUSED,
void *dis_info,
unsigned long value,
unsigned int attrs ATTRIBUTE_UNUSED,
bfd_vma pc ATTRIBUTE_UNUSED,
int length ATTRIBUTE_UNUSED)
{
disassemble_info *info = (disassemble_info *) dis_info;
(*info->fprintf_func) (info->stream, "%lu", value);
}
/* -- */