diff options
Diffstat (limited to 'arch/x86/tools/insn_sanity.c')
| -rw-r--r-- | arch/x86/tools/insn_sanity.c | 265 |
1 files changed, 265 insertions, 0 deletions
diff --git a/arch/x86/tools/insn_sanity.c b/arch/x86/tools/insn_sanity.c new file mode 100644 index 000000000..213f35f94 --- /dev/null +++ b/arch/x86/tools/insn_sanity.c @@ -0,0 +1,265 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * x86 decoder sanity test - based on test_get_insn.c + * + * Copyright (C) IBM Corporation, 2009 + * Copyright (C) Hitachi, Ltd., 2011 + */ + +#include <stdlib.h> +#include <stdio.h> +#include <string.h> +#include <assert.h> +#include <unistd.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <fcntl.h> +#include <asm/insn.h> +#include <inat.c> +#include <insn.c> + +/* + * Test of instruction analysis against tampering. + * Feed random binary to instruction decoder and ensure not to + * access out-of-instruction-buffer. + */ + +#define DEFAULT_MAX_ITER 10000 +#define INSN_NOP 0x90 + +static const char *prog; /* Program name */ +static int verbose; /* Verbosity */ +static int x86_64; /* x86-64 bit mode flag */ +static unsigned int seed; /* Random seed */ +static unsigned long iter_start; /* Start of iteration number */ +static unsigned long iter_end = DEFAULT_MAX_ITER; /* End of iteration number */ +static FILE *input_file; /* Input file name */ + +static void usage(const char *err) +{ + if (err) + fprintf(stderr, "%s: Error: %s\n\n", prog, err); + fprintf(stderr, "Usage: %s [-y|-n|-v] [-s seed[,no]] [-m max] [-i input]\n", prog); + fprintf(stderr, "\t-y 64bit mode\n"); + fprintf(stderr, "\t-n 32bit mode\n"); + fprintf(stderr, "\t-v Verbosity(-vv dumps any decoded result)\n"); + fprintf(stderr, "\t-s Give a random seed (and iteration number)\n"); + fprintf(stderr, "\t-m Give a maximum iteration number\n"); + fprintf(stderr, "\t-i Give an input file with decoded binary\n"); + exit(1); +} + +static void dump_field(FILE *fp, const char *name, const char *indent, + struct insn_field *field) +{ + fprintf(fp, "%s.%s = {\n", indent, name); + fprintf(fp, "%s\t.value = %d, bytes[] = {%x, %x, %x, %x},\n", + indent, field->value, field->bytes[0], field->bytes[1], + field->bytes[2], field->bytes[3]); + fprintf(fp, "%s\t.got = %d, .nbytes = %d},\n", indent, + field->got, field->nbytes); +} + +static void dump_insn(FILE *fp, struct insn *insn) +{ + fprintf(fp, "Instruction = {\n"); + dump_field(fp, "prefixes", "\t", &insn->prefixes); + dump_field(fp, "rex_prefix", "\t", &insn->rex_prefix); + dump_field(fp, "vex_prefix", "\t", &insn->vex_prefix); + dump_field(fp, "opcode", "\t", &insn->opcode); + dump_field(fp, "modrm", "\t", &insn->modrm); + dump_field(fp, "sib", "\t", &insn->sib); + dump_field(fp, "displacement", "\t", &insn->displacement); + dump_field(fp, "immediate1", "\t", &insn->immediate1); + dump_field(fp, "immediate2", "\t", &insn->immediate2); + fprintf(fp, "\t.attr = %x, .opnd_bytes = %d, .addr_bytes = %d,\n", + insn->attr, insn->opnd_bytes, insn->addr_bytes); + fprintf(fp, "\t.length = %d, .x86_64 = %d, .kaddr = %p}\n", + insn->length, insn->x86_64, insn->kaddr); +} + +static void dump_stream(FILE *fp, const char *msg, unsigned long nr_iter, + unsigned char *insn_buff, struct insn *insn) +{ + int i; + + fprintf(fp, "%s:\n", msg); + + dump_insn(fp, insn); + + fprintf(fp, "You can reproduce this with below command(s);\n"); + + /* Input a decoded instruction sequence directly */ + fprintf(fp, " $ echo "); + for (i = 0; i < MAX_INSN_SIZE; i++) + fprintf(fp, " %02x", insn_buff[i]); + fprintf(fp, " | %s -i -\n", prog); + + if (!input_file) { + fprintf(fp, "Or \n"); + /* Give a seed and iteration number */ + fprintf(fp, " $ %s -s 0x%x,%lu\n", prog, seed, nr_iter); + } +} + +static void init_random_seed(void) +{ + int fd; + + fd = open("/dev/urandom", O_RDONLY); + if (fd < 0) + goto fail; + + if (read(fd, &seed, sizeof(seed)) != sizeof(seed)) + goto fail; + + close(fd); + return; +fail: + usage("Failed to open /dev/urandom"); +} + +/* Read given instruction sequence from the input file */ +static int read_next_insn(unsigned char *insn_buff) +{ + char buf[256] = "", *tmp; + int i; + + tmp = fgets(buf, ARRAY_SIZE(buf), input_file); + if (tmp == NULL || feof(input_file)) + return 0; + + for (i = 0; i < MAX_INSN_SIZE; i++) { + insn_buff[i] = (unsigned char)strtoul(tmp, &tmp, 16); + if (*tmp != ' ') + break; + } + + return i; +} + +static int generate_insn(unsigned char *insn_buff) +{ + int i; + + if (input_file) + return read_next_insn(insn_buff); + + /* Fills buffer with random binary up to MAX_INSN_SIZE */ + for (i = 0; i < MAX_INSN_SIZE - 1; i += 2) + *(unsigned short *)(&insn_buff[i]) = random() & 0xffff; + + while (i < MAX_INSN_SIZE) + insn_buff[i++] = random() & 0xff; + + return i; +} + +static void parse_args(int argc, char **argv) +{ + int c; + char *tmp = NULL; + int set_seed = 0; + + prog = argv[0]; + while ((c = getopt(argc, argv, "ynvs:m:i:")) != -1) { + switch (c) { + case 'y': + x86_64 = 1; + break; + case 'n': + x86_64 = 0; + break; + case 'v': + verbose++; + break; + case 'i': + if (strcmp("-", optarg) == 0) + input_file = stdin; + else + input_file = fopen(optarg, "r"); + if (!input_file) + usage("Failed to open input file"); + break; + case 's': + seed = (unsigned int)strtoul(optarg, &tmp, 0); + if (*tmp == ',') { + optarg = tmp + 1; + iter_start = strtoul(optarg, &tmp, 0); + } + if (*tmp != '\0' || tmp == optarg) + usage("Failed to parse seed"); + set_seed = 1; + break; + case 'm': + iter_end = strtoul(optarg, &tmp, 0); + if (*tmp != '\0' || tmp == optarg) + usage("Failed to parse max_iter"); + break; + default: + usage(NULL); + } + } + + /* Check errors */ + if (iter_end < iter_start) + usage("Max iteration number must be bigger than iter-num"); + + if (set_seed && input_file) + usage("Don't use input file (-i) with random seed (-s)"); + + /* Initialize random seed */ + if (!input_file) { + if (!set_seed) /* No seed is given */ + init_random_seed(); + srand(seed); + } +} + +int main(int argc, char **argv) +{ + int insns = 0, ret; + struct insn insn; + int errors = 0; + unsigned long i; + unsigned char insn_buff[MAX_INSN_SIZE * 2]; + + parse_args(argc, argv); + + /* Prepare stop bytes with NOPs */ + memset(insn_buff + MAX_INSN_SIZE, INSN_NOP, MAX_INSN_SIZE); + + for (i = 0; i < iter_end; i++) { + if (generate_insn(insn_buff) <= 0) + break; + + if (i < iter_start) /* Skip to given iteration number */ + continue; + + /* Decode an instruction */ + ret = insn_decode(&insn, insn_buff, sizeof(insn_buff), + x86_64 ? INSN_MODE_64 : INSN_MODE_32); + + if (insn.next_byte <= insn.kaddr || + insn.kaddr + MAX_INSN_SIZE < insn.next_byte) { + /* Access out-of-range memory */ + dump_stream(stderr, "Error: Found an access violation", i, insn_buff, &insn); + errors++; + } else if (verbose && ret < 0) + dump_stream(stdout, "Info: Found an undecodable input", i, insn_buff, &insn); + else if (verbose >= 2) + dump_insn(stdout, &insn); + insns++; + } + + fprintf((errors) ? stderr : stdout, + "%s: %s: decoded and checked %d %s instructions with %d errors (seed:0x%x)\n", + prog, + (errors) ? "Failure" : "Success", + insns, + (input_file) ? "given" : "random", + errors, + seed); + + return errors ? 1 : 0; +} |