[v4,perf,bpf,12/15] perf, bpf: enable annotation of bpf program
diff mbox series

Message ID 20190226002019.3748539-13-songliubraving@fb.com
State Changes Requested
Delegated to: BPF Maintainers
Headers show
Series
  • perf annotation of BPF programs
Related show

Commit Message

Song Liu Feb. 26, 2019, 12:20 a.m. UTC
This patch enables the annotation of bpf program.

A new dso type DSO_BINARY_TYPE__BPF_PROG_INFO is introduced to for BPF
programs. In symbol__disassemble(), DSO_BINARY_TYPE__BPF_PROG_INFO dso
calls into a new function symbol__disassemble_bpf(), where annotation
line information is filled based bpf_prog_info and btf saved in given
perf_env.

symbol__disassemble_bpf() uses libbfd to disassemble bpf programs.

Signed-off-by: Song Liu <songliubraving@fb.com>
---
 tools/build/Makefile.feature |   6 +-
 tools/perf/Makefile.config   |   4 +
 tools/perf/util/annotate.c   | 149 ++++++++++++++++++++++++++++++++++-
 tools/perf/util/dso.c        |   1 +
 tools/perf/util/dso.h        |  33 +++++---
 tools/perf/util/header.c     |   7 +-
 tools/perf/util/symbol.c     |   1 +
 tools/perf/util/util.c       |  10 +++
 tools/perf/util/util.h       |   2 +
 9 files changed, 193 insertions(+), 20 deletions(-)

Comments

Jiri Olsa Feb. 27, 2019, 1:21 p.m. UTC | #1
On Mon, Feb 25, 2019 at 04:20:16PM -0800, Song Liu wrote:

SNIP

> diff --git a/tools/perf/util/util.c b/tools/perf/util/util.c
> index 093352e93d50..0bc9ec69f38a 100644
> --- a/tools/perf/util/util.c
> +++ b/tools/perf/util/util.c
> @@ -506,3 +506,13 @@ const char *perf_tip(const char *dirpath)
>  
>  	return tip;
>  }
> +
> +void get_exec_path(char *tpath, size_t size)
> +{
> +	const char *path = "/proc/self/exe";
> +	ssize_t len;
> +
> +	len = readlink(path, tpath, size - 1);
> +	assert(len > 0);
> +	tpath[len] = 0;
> +}

we have now helper for that, please rebase this on top of
arnaldo's perf/core:

  94816add0005 perf tools: Add perf_exe() helper to find perf binary

jirka
Jiri Olsa Feb. 27, 2019, 1:22 p.m. UTC | #2
On Mon, Feb 25, 2019 at 04:20:16PM -0800, Song Liu wrote:

SNIP

> +		if (!opts->hide_src_code && srcline) {
> +			args->offset = -1;
> +			args->line = strdup(srcline);
> +			args->line_nr = 0;
> +			args->ms.sym  = sym;
> +			dl = disasm_line__new(args);
> +			if (dl)
> +				annotation_line__add(&dl->al,
> +						     &notes->src->source);

please use { } around multiline if leg

jirka

Patch
diff mbox series

diff --git a/tools/build/Makefile.feature b/tools/build/Makefile.feature
index 5467c6bf9ceb..4f35e9ff1e00 100644
--- a/tools/build/Makefile.feature
+++ b/tools/build/Makefile.feature
@@ -71,7 +71,8 @@  FEATURE_TESTS_BASIC :=                  \
         sdt				\
         setns				\
         libopencsd			\
-        libaio
+        libaio				\
+        disassembler-four-args
 
 # FEATURE_TESTS_BASIC + FEATURE_TESTS_EXTRA is the complete list
 # of all feature tests
@@ -118,7 +119,8 @@  FEATURE_DISPLAY ?=              \
          lzma                   \
          get_cpuid              \
          bpf			\
-         libaio
+         libaio			\
+         disassembler-four-args
 
 # Set FEATURE_CHECK_(C|LD)FLAGS-all for all FEATURE_TESTS features.
 # If in the future we need per-feature checks/flags for features not
diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
index e0bafbc273af..ab223239f1fb 100644
--- a/tools/perf/Makefile.config
+++ b/tools/perf/Makefile.config
@@ -796,6 +796,10 @@  ifdef HAVE_KVM_STAT_SUPPORT
     CFLAGS += -DHAVE_KVM_STAT_SUPPORT
 endif
 
+ifeq ($(feature-disassembler-four-args), 1)
+    CFLAGS += -DDISASM_FOUR_ARGS_SIGNATURE
+endif
+
 ifeq (${IS_64_BIT}, 1)
   ifndef NO_PERF_READ_VDSO32
     $(call feature_check,compile-32)
diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c
index 70de8f6b3aee..716fdb07f45e 100644
--- a/tools/perf/util/annotate.c
+++ b/tools/perf/util/annotate.c
@@ -9,6 +9,10 @@ 
 
 #include <errno.h>
 #include <inttypes.h>
+#include <bpf/bpf.h>
+#include <bpf/btf.h>
+#include <bpf/libbpf.h>
+#include <linux/btf.h>
 #include "util.h"
 #include "ui/ui.h"
 #include "sort.h"
@@ -22,6 +26,7 @@ 
 #include "annotate.h"
 #include "evsel.h"
 #include "evlist.h"
+#include "bpf-event.h"
 #include "block-range.h"
 #include "string2.h"
 #include "arch/common.h"
@@ -29,6 +34,9 @@ 
 #include <pthread.h>
 #include <linux/bitops.h>
 #include <linux/kernel.h>
+#include <bfd.h>
+#include <dis-asm.h>
+#include <bpf/libbpf.h>
 
 /* FIXME: For the HE_COLORSET */
 #include "ui/browser.h"
@@ -1672,6 +1680,143 @@  static int dso__disassemble_filename(struct dso *dso, char *filename, size_t fil
 	return 0;
 }
 
+static int symbol__disassemble_bpf(struct symbol *sym,
+				   struct annotate_args *args)
+{
+	struct annotation *notes = symbol__annotation(sym);
+	struct annotation_options *opts = args->options;
+	struct bpf_prog_info_linear *info_linear;
+	struct bpf_prog_linfo *prog_linfo = NULL;
+	struct bpf_prog_info_node *info_node;
+	int len = sym->end - sym->start;
+	disassembler_ftype disassemble;
+	struct map *map = args->ms.map;
+	struct disassemble_info info;
+	struct dso *dso = map->dso;
+	int pc = 0, count, sub_id;
+	struct btf *btf = NULL;
+	char tpath[PATH_MAX];
+	size_t buf_size;
+	int nr_skip = 0;
+	int ret = -1;
+	char *buf;
+	bfd *bfdf;
+	FILE *s;
+
+	if (dso->binary_type != DSO_BINARY_TYPE__BPF_PROG_INFO)
+		return -1;
+
+	pr_debug("%s: handling sym %s addr %lx len %lx\n", __func__,
+		 sym->name, sym->start, sym->end - sym->start);
+
+	memset(tpath, 0, sizeof(tpath));
+	get_exec_path(tpath, sizeof(tpath));
+
+	bfdf = bfd_openr(tpath, NULL);
+	assert(bfdf);
+	assert(bfd_check_format(bfdf, bfd_object));
+
+	s = open_memstream(&buf, &buf_size);
+	if (!s)
+		goto out;
+	init_disassemble_info(&info, s,
+			      (fprintf_ftype) fprintf);
+
+	info.arch = bfd_get_arch(bfdf);
+	info.mach = bfd_get_mach(bfdf);
+
+	info_node = perf_env__find_bpf_prog_info(dso->bpf_prog.env,
+						 dso->bpf_prog.id);
+	if (!info_node)
+		goto out;
+	info_linear = info_node->info_linear;
+	sub_id = dso->bpf_prog.sub_id;
+
+	info.buffer = (void *)(info_linear->info.jited_prog_insns);
+	info.buffer_length = info_linear->info.jited_prog_len;
+
+	if (info_linear->info.nr_line_info)
+		prog_linfo = bpf_prog_linfo__new(&info_linear->info);
+
+	if (info_linear->info.btf_id) {
+		struct btf_node *node;
+
+		node = perf_env__find_btf(dso->bpf_prog.env,
+					  info_linear->info.btf_id);
+		if (node)
+			btf = btf__new((__u8 *)(node->data),
+				       node->data_size);
+	}
+
+	disassemble_init_for_target(&info);
+
+#ifdef DISASM_FOUR_ARGS_SIGNATURE
+	disassemble = disassembler(info.arch,
+				   bfd_big_endian(bfdf),
+				   info.mach,
+				   bfdf);
+#else
+	disassemble = disassembler(bfdf);
+#endif
+	assert(disassemble);
+
+	fflush(s);
+	do {
+		const struct bpf_line_info *linfo = NULL;
+		struct disasm_line *dl;
+		size_t prev_buf_size;
+		const char *srcline;
+		u64 addr;
+
+		addr = pc + ((u64 *)(info_linear->info.jited_ksyms))[sub_id];
+		count = disassemble(pc, &info);
+
+		if (prog_linfo)
+			linfo = bpf_prog_linfo__lfind_addr_func(prog_linfo,
+								addr, sub_id,
+								nr_skip);
+
+		if (linfo && btf) {
+			srcline = btf__name_by_offset(btf, linfo->line_off);
+			nr_skip++;
+		} else
+			srcline = NULL;
+
+		fprintf(s, "\n");
+		prev_buf_size = buf_size;
+		fflush(s);
+
+		if (!opts->hide_src_code && srcline) {
+			args->offset = -1;
+			args->line = strdup(srcline);
+			args->line_nr = 0;
+			args->ms.sym  = sym;
+			dl = disasm_line__new(args);
+			if (dl)
+				annotation_line__add(&dl->al,
+						     &notes->src->source);
+		}
+
+		args->offset = pc;
+		args->line = buf + prev_buf_size;
+		args->line_nr = 0;
+		args->ms.sym  = sym;
+		dl = disasm_line__new(args);
+		if (dl)
+			annotation_line__add(&dl->al, &notes->src->source);
+
+		pc += count;
+	} while (count > 0 && pc < len);
+
+	ret = 0;
+out:
+	free(prog_linfo);
+	free(btf);
+	fclose(s);
+	bfd_close(bfdf);
+	return ret;
+}
+
 static int symbol__disassemble(struct symbol *sym, struct annotate_args *args)
 {
 	struct annotation_options *opts = args->options;
@@ -1699,7 +1844,9 @@  static int symbol__disassemble(struct symbol *sym, struct annotate_args *args)
 	pr_debug("annotating [%p] %30s : [%p] %30s\n",
 		 dso, dso->long_name, sym, sym->name);
 
-	if (dso__is_kcore(dso)) {
+	if (dso->binary_type == DSO_BINARY_TYPE__BPF_PROG_INFO) {
+		return symbol__disassemble_bpf(sym, args);
+	} else if (dso__is_kcore(dso)) {
 		kce.kcore_filename = symfs_filename;
 		kce.addr = map__rip_2objdump(map, sym->start);
 		kce.offs = sym->start;
diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c
index 62c8cf622607..1798192bf0f9 100644
--- a/tools/perf/util/dso.c
+++ b/tools/perf/util/dso.c
@@ -181,6 +181,7 @@  int dso__read_binary_type_filename(const struct dso *dso,
 	case DSO_BINARY_TYPE__KALLSYMS:
 	case DSO_BINARY_TYPE__GUEST_KALLSYMS:
 	case DSO_BINARY_TYPE__JAVA_JIT:
+	case DSO_BINARY_TYPE__BPF_PROG_INFO:
 	case DSO_BINARY_TYPE__NOT_FOUND:
 		ret = -1;
 		break;
diff --git a/tools/perf/util/dso.h b/tools/perf/util/dso.h
index 8c8a7abe809d..f20d319463f1 100644
--- a/tools/perf/util/dso.h
+++ b/tools/perf/util/dso.h
@@ -14,6 +14,8 @@ 
 #include "namespaces.h"
 #include "build-id.h"
 
+struct perf_env;
+
 enum dso_binary_type {
 	DSO_BINARY_TYPE__KALLSYMS = 0,
 	DSO_BINARY_TYPE__GUEST_KALLSYMS,
@@ -34,6 +36,7 @@  enum dso_binary_type {
 	DSO_BINARY_TYPE__KCORE,
 	DSO_BINARY_TYPE__GUEST_KCORE,
 	DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO,
+	DSO_BINARY_TYPE__BPF_PROG_INFO,
 	DSO_BINARY_TYPE__NOT_FOUND,
 };
 
@@ -177,17 +180,25 @@  struct dso {
 	struct auxtrace_cache *auxtrace_cache;
 	int		 comp;
 
-	/* dso data file */
-	struct {
-		struct rb_root	 cache;
-		int		 fd;
-		int		 status;
-		u32		 status_seen;
-		size_t		 file_size;
-		struct list_head open_entry;
-		u64		 debug_frame_offset;
-		u64		 eh_frame_hdr_offset;
-	} data;
+	union {
+		/* dso data file */
+		struct {
+			struct rb_root	 cache;
+			int		 fd;
+			int		 status;
+			u32		 status_seen;
+			size_t		 file_size;
+			struct list_head open_entry;
+			u64		 debug_frame_offset;
+			u64		 eh_frame_hdr_offset;
+		} data;
+		/* bpf prog information */
+		struct {
+			u32		id;
+			u32		sub_id;
+			struct perf_env	*env;
+		} bpf_prog;
+	};
 
 	union { /* Tool specific area */
 		void	 *priv;
diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index ce5402101468..c39e107ac5b8 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -533,12 +533,7 @@  static int write_cmdline(struct feat_fd *ff,
 	int i, ret;
 
 	/* actual path to perf binary */
-	ret = readlink("/proc/self/exe", buf, sizeof(buf) - 1);
-	if (ret <= 0)
-		return -1;
-
-	/* readlink() does not add null termination */
-	buf[ret] = '\0';
+	get_exec_path(buf, sizeof(buf));
 
 	/* account for binary path */
 	n = perf_env.nr_cmdline + 1;
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 48efad6d0f90..33ae59e89da2 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -1441,6 +1441,7 @@  static bool dso__is_compatible_symtab_type(struct dso *dso, bool kmod,
 	case DSO_BINARY_TYPE__BUILD_ID_CACHE_DEBUGINFO:
 		return true;
 
+	case DSO_BINARY_TYPE__BPF_PROG_INFO:
 	case DSO_BINARY_TYPE__NOT_FOUND:
 	default:
 		return false;
diff --git a/tools/perf/util/util.c b/tools/perf/util/util.c
index 093352e93d50..0bc9ec69f38a 100644
--- a/tools/perf/util/util.c
+++ b/tools/perf/util/util.c
@@ -506,3 +506,13 @@  const char *perf_tip(const char *dirpath)
 
 	return tip;
 }
+
+void get_exec_path(char *tpath, size_t size)
+{
+	const char *path = "/proc/self/exe";
+	ssize_t len;
+
+	len = readlink(path, tpath, size - 1);
+	assert(len > 0);
+	tpath[len] = 0;
+}
diff --git a/tools/perf/util/util.h b/tools/perf/util/util.h
index ece040b799f6..8d0a88eb8685 100644
--- a/tools/perf/util/util.h
+++ b/tools/perf/util/util.h
@@ -76,6 +76,8 @@  extern bool perf_singlethreaded;
 void perf_set_singlethreaded(void);
 void perf_set_multithreaded(void);
 
+void get_exec_path(char *tpath, size_t size);
+
 #ifndef O_CLOEXEC
 #ifdef __sparc__
 #define O_CLOEXEC      0x400000