1 /* Main simulator entry points specific to the eBPF.
2 Copyright (C) 2020-2021 Free Software Foundation, Inc.
4 This file is part of GDB, the GNU debugger.
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program. If not, see <http://www.gnu.org/licenses/>. */
19 /* This must come before any other includes. */
25 #include "sim-options.h"
26 #include "libiberty.h"
31 /* String with the name of the section containing the BPF program to
33 static char *bpf_program_section
= NULL
;
35 extern uint64_t skb_data_offset
;
38 /* Handle BPF-specific options. */
40 static SIM_RC
bpf_option_handler (SIM_DESC
, sim_cpu
*, int, char *, int);
44 OPTION_BPF_SET_PROGRAM
= OPTION_START
,
45 OPTION_BPF_LIST_PROGRAMS
,
46 OPTION_BPF_VERIFY_PROGRAM
,
47 OPTION_BPF_SKB_DATA_OFFSET
,
50 static const OPTION bpf_options
[] =
52 { {"bpf-set-program", required_argument
, NULL
, OPTION_BPF_SET_PROGRAM
},
53 '\0', "SECTION_NAME", "Set the entry point",
55 { {"bpf-list-programs", no_argument
, NULL
, OPTION_BPF_LIST_PROGRAMS
},
56 '\0', "", "List loaded bpf programs",
58 { {"bpf-verify-program", required_argument
, NULL
, OPTION_BPF_VERIFY_PROGRAM
},
59 '\0', "PROGRAM", "Run the verifier on the given BPF program",
61 { {"skb-data-offset", required_argument
, NULL
, OPTION_BPF_SKB_DATA_OFFSET
},
62 '\0', "OFFSET", "Configure offsetof(struct sk_buff, data)",
65 { {NULL
, no_argument
, NULL
, 0}, '\0', NULL
, NULL
, NULL
, NULL
}
69 bpf_option_handler (SIM_DESC sd
, sim_cpu
*cpu ATTRIBUTE_UNUSED
, int opt
,
70 char *arg
, int is_command ATTRIBUTE_UNUSED
)
72 switch ((BPF_OPTION
) opt
)
74 case OPTION_BPF_VERIFY_PROGRAM
:
75 /* XXX call the verifier. */
76 sim_io_printf (sd
, "Verifying BPF program %s...\n", arg
);
79 case OPTION_BPF_LIST_PROGRAMS
:
80 /* XXX list programs. */
81 sim_io_printf (sd
, "BPF programs available:\n");
84 case OPTION_BPF_SET_PROGRAM
:
85 /* XXX: check that the section exists and tell the user about a
87 bpf_program_section
= xstrdup (arg
);
90 case OPTION_BPF_SKB_DATA_OFFSET
:
91 skb_data_offset
= strtoul (arg
, NULL
, 0);
95 sim_io_eprintf (sd
, "Unknown option `%s'\n", arg
);
102 /* Like sim_state_free, but free the cpu buffers as well. */
105 bpf_free_state (SIM_DESC sd
)
107 if (STATE_MODULES (sd
) != NULL
)
108 sim_module_uninstall (sd
);
110 sim_cpu_free_all (sd
);
114 /* Create an instance of the simulator. */
117 sim_open (SIM_OPEN_KIND kind
,
118 host_callback
*callback
,
122 /* XXX Analyze the program, and collect per-function information
123 like the kernel verifier does. The implementation of the CALL
124 instruction will need that information, to update %fp. */
126 SIM_DESC sd
= sim_state_alloc (kind
, callback
);
128 if (sim_cpu_alloc_all (sd
, 1) != SIM_RC_OK
)
131 if (sim_pre_argv_init (sd
, argv
[0]) != SIM_RC_OK
)
134 /* Add the BPF-specific option list to the simulator. */
135 if (sim_add_option_table (sd
, NULL
, bpf_options
) != SIM_RC_OK
)
141 if (sim_parse_args (sd
, argv
) != SIM_RC_OK
)
144 if (sim_analyze_program (sd
,
145 (STATE_PROG_ARGV (sd
) != NULL
146 ? *STATE_PROG_ARGV (sd
)
147 : NULL
), abfd
) != SIM_RC_OK
)
150 if (sim_config (sd
) != SIM_RC_OK
)
153 if (sim_post_argv_init (sd
) != SIM_RC_OK
)
158 /* Initialize the CPU descriptors and the disassemble in the cpu
159 descriptor table entries. */
162 CGEN_CPU_DESC cd
= bpf_cgen_cpu_open_1 (STATE_ARCHITECTURE (sd
)->printable_name
,
165 /* We have one cpu per installed program! MAX_NR_PROCESSORS is an
166 arbitrary upper limit. XXX where is it defined? */
167 for (i
= 0; i
< MAX_NR_PROCESSORS
; ++i
)
169 SIM_CPU
*cpu
= STATE_CPU (sd
, i
);
171 CPU_CPU_DESC (cpu
) = cd
;
172 CPU_DISASSEMBLER (cpu
) = sim_cgen_disassemble_insn
;
175 bpf_cgen_init_dis (cd
);
178 /* XXX do eBPF sim specific initializations. */
189 sim_create_inferior (SIM_DESC sd
, struct bfd
*abfd
,
190 char *const *argv
, char *const *envp
)
192 SIM_CPU
*current_cpu
= STATE_CPU (sd
, 0);
195 /* Determine the start address.
197 XXX acknowledge bpf_program_section. If it is NULL, emit a
198 warning explaining that we are using the ELF file start address,
199 which often is not what is actually wanted. */
201 addr
= bfd_get_start_address (abfd
);
205 sim_pc_set (current_cpu
, addr
);
207 if (STATE_PROG_ARGV (sd
) != argv
)
209 freeargv (STATE_PROG_ARGV (sd
));
210 STATE_PROG_ARGV (sd
) = dupargv (argv
);