summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>2011-10-20 23:01:09 +0900
committerIngo Molnar <mingo@elte.hu>2011-11-10 12:38:51 +0100
commit1ec454baf1245df4fdb5dae728da3363630ce6de (patch)
tree88bf565984db893b02bfdcae81b3a1d7d351d123
parent19e0bafc36abd84a5b4d7c7745b78a6f4626e944 (diff)
downloadop-kernel-dev-1ec454baf1245df4fdb5dae728da3363630ce6de.zip
op-kernel-dev-1ec454baf1245df4fdb5dae728da3363630ce6de.tar.gz
x86, perf: Add a build-time sanity test to the x86 decoder
Add a sanity test of x86 insn decoder against a stream of randomly generated input, at build time. This test is also able to reproduce any bug that might trigger by allowing the passing of random-seed and iteration-number to the test, or by passing input which has invalid byte code. Changes in V2: - Code cleanup. - Show how to reproduce the error by insn_sanity test. Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: acme@redhat.com Cc: ming.m.lin@intel.com Cc: robert.richter@amd.com Cc: ravitillo@lbl.gov Cc: yrl.pp-manager.tt@hitachi.com Cc: Andi Kleen <andi@firstfloor.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20111020140109.20938.92572.stgit@localhost.localdomain Signed-off-by: Ingo Molnar <mingo@elte.hu>
-rw-r--r--arch/x86/include/asm/insn.h7
-rw-r--r--arch/x86/tools/Makefile10
-rw-r--r--arch/x86/tools/insn_sanity.c275
3 files changed, 291 insertions, 1 deletions
diff --git a/arch/x86/include/asm/insn.h b/arch/x86/include/asm/insn.h
index 88c765e..74df3f1 100644
--- a/arch/x86/include/asm/insn.h
+++ b/arch/x86/include/asm/insn.h
@@ -137,6 +137,13 @@ static inline int insn_is_avx(struct insn *insn)
return (insn->vex_prefix.value != 0);
}
+/* Ensure this instruction is decoded completely */
+static inline int insn_complete(struct insn *insn)
+{
+ return insn->opcode.got && insn->modrm.got && insn->sib.got &&
+ insn->displacement.got && insn->immediate.got;
+}
+
static inline insn_byte_t insn_vex_m_bits(struct insn *insn)
{
if (insn->vex_prefix.nbytes == 2) /* 2 bytes VEX */
diff --git a/arch/x86/tools/Makefile b/arch/x86/tools/Makefile
index f820826..3255c3d 100644
--- a/arch/x86/tools/Makefile
+++ b/arch/x86/tools/Makefile
@@ -18,14 +18,22 @@ chkobjdump = $(srctree)/arch/x86/tools/chkobjdump.awk
quiet_cmd_posttest = TEST $@
cmd_posttest = ($(OBJDUMP) -v | $(AWK) -f $(chkobjdump)) || $(OBJDUMP) -d -j .text $(objtree)/vmlinux | $(AWK) -f $(distill_awk) | $(obj)/test_get_len $(posttest_64bit) $(posttest_verbose)
-posttest: $(obj)/test_get_len vmlinux
+quiet_cmd_sanitytest = TEST $@
+ cmd_sanitytest = $(obj)/insn_sanity $(posttest_64bit) -m 1000000
+
+posttest: $(obj)/test_get_len vmlinux $(obj)/insn_sanity
$(call cmd,posttest)
+ $(call cmd,sanitytest)
hostprogs-y := test_get_len
+hostprogs-y := insn_sanity
# -I needed for generated C source and C source which in the kernel tree.
HOSTCFLAGS_test_get_len.o := -Wall -I$(objtree)/arch/x86/lib/ -I$(srctree)/arch/x86/include/ -I$(srctree)/arch/x86/lib/ -I$(srctree)/include/
+HOSTCFLAGS_insn_sanity.o := -Wall -I$(objtree)/arch/x86/lib/ -I$(srctree)/arch/x86/include/ -I$(srctree)/arch/x86/lib/ -I$(srctree)/include/
+
# Dependencies are also needed.
$(obj)/test_get_len.o: $(srctree)/arch/x86/lib/insn.c $(srctree)/arch/x86/lib/inat.c $(srctree)/arch/x86/include/asm/inat_types.h $(srctree)/arch/x86/include/asm/inat.h $(srctree)/arch/x86/include/asm/insn.h $(objtree)/arch/x86/lib/inat-tables.c
+$(obj)/insn_sanity.o: $(srctree)/arch/x86/lib/insn.c $(srctree)/arch/x86/lib/inat.c $(srctree)/arch/x86/include/asm/inat_types.h $(srctree)/arch/x86/include/asm/inat.h $(srctree)/arch/x86/include/asm/insn.h $(objtree)/arch/x86/lib/inat-tables.c
diff --git a/arch/x86/tools/insn_sanity.c b/arch/x86/tools/insn_sanity.c
new file mode 100644
index 0000000..334d9de
--- /dev/null
+++ b/arch/x86/tools/insn_sanity.c
@@ -0,0 +1,275 @@
+/*
+ * x86 decoder sanity test - based on test_get_insn.c
+ *
+ * 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 2 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ *
+ * 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>
+
+#define unlikely(cond) (cond)
+#define ARRAY_SIZE(a) (sizeof(a)/sizeof(a[0]))
+
+#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, "Error: %s\n\n", 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 Verbose mode\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_buf, struct insn *insn)
+{
+ int i;
+
+ fprintf(fp, "%s:\n", msg);
+
+ dump_insn(stderr, 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_buf[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_buf)
+{
+ 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_buf[i] = (unsigned char)strtoul(tmp, &tmp, 16);
+ if (*tmp != ' ')
+ break;
+ }
+
+ return i;
+}
+
+static int generate_insn(unsigned char *insn_buf)
+{
+ int i;
+
+ if (input_file)
+ return read_next_insn(insn_buf);
+
+ /* Fills buffer with random binary up to MAX_INSN_SIZE */
+ for (i = 0; i < MAX_INSN_SIZE - 1; i += 2)
+ *(unsigned short *)(&insn_buf[i]) = random() & 0xffff;
+
+ while (i < MAX_INSN_SIZE)
+ insn_buf[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 = 1;
+ 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)
+{
+ struct insn insn;
+ int insns = 0;
+ int errors = 0;
+ unsigned long i;
+ unsigned char insn_buf[MAX_INSN_SIZE * 2];
+
+ parse_args(argc, argv);
+
+ /* Prepare stop bytes with NOPs */
+ memset(insn_buf + MAX_INSN_SIZE, INSN_NOP, MAX_INSN_SIZE);
+
+ for (i = 0; i < iter_end; i++) {
+ if (generate_insn(insn_buf) <= 0)
+ break;
+
+ if (i < iter_start) /* Skip to given iteration number */
+ continue;
+
+ /* Decode an instruction */
+ insn_init(&insn, insn_buf, x86_64);
+ insn_get_length(&insn);
+
+ if (verbose && !insn_complete(&insn))
+ dump_stream(stdout, "Info: Found an undecodable input", i, insn_buf, &insn);
+
+ if (insn.next_byte <= insn.kaddr ||
+ insn.kaddr + MAX_INSN_SIZE < insn.next_byte) {
+ /* Access out-of-range memory */
+ dump_stream(stdout, "Error: Found an access violation", i, insn_buf, &insn);
+ errors++;
+ }
+ insns++;
+ }
+
+ fprintf(stdout, "%s: decoded and checked %d %s instructions with %d errors (seed:0x%x)\n", (errors) ? "Failure" : "Success", insns, (input_file) ? "given" : "random", errors, seed);
+
+ return errors ? 1 : 0;
+}
OpenPOWER on IntegriCloud