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Subject[PATCH 06/13] perf bpf: Add disasm option
Date
Add -d/--disasm option to get the sbpf assembly
code dump, like:

$ perf bpf -d ./comm1.o | head
Disassembly of raw_syscalls:sys_enter:
0: (b7) r1 = 1
b7 01 00 00 01 00 00 00
1: (7b) *(u64 *)(r10 -8) = r1
7b 1a f8 ff 00 00 00 00
2: (bf) r6 = r10
bf a6 00 00 00 00 00 00
3: (07) r6 += -24
07 06 00 00 e8 ff ff ff
4: (bf) r1 = r6
...

Link: http://lkml.kernel.org/n/tip-djopq2e6ajsg9h90hb9iuat3@git.kernel.org
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
tools/perf/Build | 6 +++
tools/perf/Makefile.config | 1 +
tools/perf/builtin-bpf.c | 107 +++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 114 insertions(+)

diff --git a/tools/perf/Build b/tools/perf/Build
index 7f521ac16466..0585fd3715d0 100644
--- a/tools/perf/Build
+++ b/tools/perf/Build
@@ -25,6 +25,7 @@ perf-y += builtin-data.o
perf-y += builtin-version.o
perf-y += builtin-c2c.o
perf-y += builtin-bpf.o
+perf-y += bpf-disasm.o

perf-$(CONFIG_TRACE) += builtin-trace.o
perf-$(CONFIG_LIBELF) += builtin-probe.o
@@ -46,6 +47,7 @@ CFLAGS_perf.o += -DPERF_HTML_PATH="BUILD_STR($(htmldir_SQ))" \
CFLAGS_builtin-trace.o += -DSTRACE_GROUPS_DIR="BUILD_STR($(STRACE_GROUPS_DIR_SQ))"
CFLAGS_builtin-report.o += -DTIPDIR="BUILD_STR($(tipdir_SQ))"
CFLAGS_builtin-report.o += -DDOCDIR="BUILD_STR($(srcdir_SQ)/Documentation)"
+CFLAGS_builtin-bpf.o += -I$(srctree)/kernel/bpf

libperf-y += util/
libperf-y += arch/
@@ -54,3 +56,7 @@ libperf-y += scripts/
libperf-$(CONFIG_TRACE) += trace/beauty/

gtk-y += ui/gtk/
+
+$(OUTPUT)bpf-disasm.o: ../../kernel/bpf/disasm.c FORCE
+ $(call rule_mkdir)
+ $(call if_changed_dep,cc_o_c)
diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
index 98ff73648b51..575910cebb57 100644
--- a/tools/perf/Makefile.config
+++ b/tools/perf/Makefile.config
@@ -999,3 +999,4 @@ $(call detected_var,LIBDIR)
$(call detected_var,GTK_CFLAGS)
$(call detected_var,PERL_EMBED_CCOPTS)
$(call detected_var,PYTHON_EMBED_CCOPTS)
+$(call detected_var,srctree)
diff --git a/tools/perf/builtin-bpf.c b/tools/perf/builtin-bpf.c
index 1ae93fd01a97..7065153a9577 100644
--- a/tools/perf/builtin-bpf.c
+++ b/tools/perf/builtin-bpf.c
@@ -4,6 +4,8 @@
#include <time.h>
#include <linux/compiler.h>
#include <subcmd/parse-options.h>
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
#include "builtin.h"
#include "perf.h"
#include "target.h"
@@ -12,6 +14,7 @@
#include "evlist.h"
#include "evsel.h"
#include "bpf-loader.h"
+#include "disasm.h"

struct perf_bpf {
struct target target;
@@ -137,6 +140,104 @@ static int __cmd_bpf(int argc , const char **argv)
return WEXITSTATUS(status);
}

+static void print_insn(struct bpf_verifier_env *env __maybe_unused, const char *fmt, ...)
+{
+ va_list args;
+
+ va_start(args, fmt);
+ vprintf(fmt, args);
+ va_end(args);
+}
+
+static const char *print_call(void *private_data __maybe_unused,
+ const struct bpf_insn *insn __maybe_unused)
+{
+ return NULL;
+}
+
+static const char *print_imm(void *private_data __maybe_unused,
+ const struct bpf_insn *insn __maybe_unused,
+ __u64 full_imm __maybe_unused)
+{
+ return NULL;
+}
+
+static void fprint_hex(FILE *f, void *arg, unsigned int n, const char *sep)
+{
+ unsigned char *data = arg;
+ unsigned int i;
+
+ for (i = 0; i < n; i++) {
+ const char *pfx = "";
+
+ if (!i)
+ /* nothing */;
+ else if (!(i % 16))
+ fprintf(f, "\n");
+ else if (!(i % 8))
+ fprintf(f, " ");
+ else
+ pfx = sep;
+
+ fprintf(f, "%s%02hhx", i ? pfx : "", data[i]);
+ }
+}
+
+static int disasm_fprintf(FILE *out, const char *filename, bool opcodes)
+{
+ const struct bpf_insn_cbs cbs = {
+ .cb_print = print_insn,
+ .cb_call = print_call,
+ .cb_imm = print_imm,
+ .private_data = NULL,
+ };
+ bool double_insn = false;
+ struct bpf_program *prog;
+ struct bpf_object *obj;
+ int i;
+
+ obj = bpf__prepare_load(filename, false);
+ if (IS_ERR(obj))
+ return -1;
+
+ bpf_object__for_each_program(prog, obj) {
+ struct bpf_insn *insn;
+ int insns_cnt;
+
+ fprintf(out, "Disassembly of %s:\n", bpf_program__title(prog, false));
+
+ insn = bpf_program__insns(prog, &insns_cnt);
+ if (!insn) {
+ pr_err("failed: NULL instructions\n");
+ return -1;
+ }
+
+ for (i = 0; i < (int) insns_cnt; i++) {
+ if (double_insn) {
+ double_insn = false;
+ continue;
+ }
+
+ double_insn = insn[i].code == (BPF_LD | BPF_IMM | BPF_DW);
+
+ printf("% 4d: ", i);
+ print_bpf_insn(&cbs, NULL, insn + i, true);
+
+ if (opcodes) {
+ printf(" ");
+ fprint_hex(stdout, insn + i, 8, " ");
+ if (double_insn && i < (int) (insns_cnt*sizeof(*insn)) - 1) {
+ printf(" ");
+ fprint_hex(stdout, insn + i + 1, 8, " ");
+ }
+ printf("\n");
+ }
+ }
+ }
+
+ return 0;
+}
+
int cmd_bpf(int argc, const char **argv)
{
int err = -1;
@@ -146,6 +247,7 @@ int cmd_bpf(int argc, const char **argv)
NULL
};
const char *compile_src = NULL;
+ const char *disasm_obj = NULL;
const struct option bpf_options[] = {
OPT_CALLBACK('e', "event", &bpf.evlist, "event",
"event selector. use 'perf list' to list available events",
@@ -162,6 +264,8 @@ int cmd_bpf(int argc, const char **argv)
"be more verbose"),
OPT_STRING('c', "compile", &compile_src, "eBPF source",
"compile eBPF object"),
+ OPT_STRING('d', "disasm", &disasm_obj, "eBPF object",
+ "disasm eBPF object"),
OPT_END()
};

@@ -177,6 +281,9 @@ int cmd_bpf(int argc, const char **argv)
if (compile_src)
return bpf__compile(compile_src);

+ if (disasm_obj)
+ return disasm_fprintf(stdout, disasm_obj, true);
+
if (!argc && target__none(&bpf.target))
usage_with_options(bpf_usage, bpf_options);

--
2.13.6
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