perf evsel: Allow unresolved symbol names to be printed as addresses

The fprintf_sym() and fprintf_callchain() methods now allow users to
change the existing behaviour of showing "[unknown]" as the name of
unresolved symbols to instead show "[0x123456]", i.e. its address.

The current patch doesn't change tools to use this facility, the results
from 'perf trace' and 'perf script' cotinue like:

70.109 ( 0.001 ms): qemu-system-x8/10153 poll(ufds: 0x7f2d93ffe870, nfds: 1) = 0 Timeout
                                   [unknown] (/usr/lib64/libc-2.22.so)
                                   [unknown] (/usr/lib64/libspice-server.so.1.10.0)
                                   [unknown] (/usr/lib64/libspice-server.so.1.10.0)
                                   [unknown] (/usr/lib64/libspice-server.so.1.10.0)
                                   start_thread+0xca (/usr/lib64/libpthread-2.22.so)
                                   __clone+0x6d (/usr/lib64/libc-2.22.so)

The next patch will make 'perf trace' use the new formatting.

Suggested-by: Milian Wolff <milian.wolff@kdab.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-fja1ods5vqpg42mdz09xcz3r@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/session.c

@@ -1966,6 +1966,7 @@ int perf_evsel__fprintf_callchain(struct perf_evsel *evsel, struct perf_sample *
 	int print_symoffset = print_opts & PRINT_IP_OPT_SYMOFFSET;
 	int print_oneline = print_opts & PRINT_IP_OPT_ONELINE;
 	int print_srcline = print_opts & PRINT_IP_OPT_SRCLINE;
+	int print_unknown_as_addr = print_opts & PRINT_IP_OPT_UNKNOWN_AS_ADDR;
 	char s = print_oneline ? ' ' : '\t';
 
 	if (sample->callchain) {
@@ -2003,12 +2004,16 @@ int perf_evsel__fprintf_callchain(struct perf_evsel *evsel, struct perf_sample *
 
 			if (print_sym) {
 				printed += fprintf(fp, " ");
+				node_al.addr = addr;
+				node_al.map  = node->map;
+
 				if (print_symoffset) {
-					node_al.addr = addr;
-					node_al.map  = node->map;
-					printed += symbol__fprintf_symname_offs(node->sym, &node_al, fp);
-				} else
-					printed += symbol__fprintf_symname(node->sym, fp);
+					printed += __symbol__fprintf_symname_offs(node->sym, &node_al,
+										  print_unknown_as_addr, fp);
+				} else {
+					printed += __symbol__fprintf_symname(node->sym, &node_al,
+									     print_unknown_as_addr, fp);
+				}
 			}
 
 			if (print_dso) {
@@ -2043,6 +2048,7 @@ int perf_evsel__fprintf_sym(struct perf_evsel *evsel, struct perf_sample *sample
 	int print_dso = print_opts & PRINT_IP_OPT_DSO;
 	int print_symoffset = print_opts & PRINT_IP_OPT_SYMOFFSET;
 	int print_srcline = print_opts & PRINT_IP_OPT_SRCLINE;
+	int print_unknown_as_addr = print_opts & PRINT_IP_OPT_UNKNOWN_AS_ADDR;
 
 	if (symbol_conf.use_callchain && sample->callchain) {
 		printed += perf_evsel__fprintf_callchain(evsel, sample, al, left_alignment,
@@ -2055,10 +2061,13 @@ int perf_evsel__fprintf_sym(struct perf_evsel *evsel, struct perf_sample *sample
 
 		if (print_sym) {
 			printed += fprintf(fp, " ");
-			if (print_symoffset)
-				printed += symbol__fprintf_symname_offs(al->sym, al, fp);
-			else
-				printed += symbol__fprintf_symname(al->sym, fp);
+			if (print_symoffset) {
+				printed += __symbol__fprintf_symname_offs(al->sym, al,
+									  print_unknown_as_addr, fp);
+			} else {
+				printed += __symbol__fprintf_symname(al->sym, al,
+								     print_unknown_as_addr, fp);
+			}
 		}
 
 		if (print_dso) {

tools/perf/util/session.h

@@ -42,6 +42,7 @@ struct perf_session {
 #define PRINT_IP_OPT_SYMOFFSET	(1<<3)
 #define PRINT_IP_OPT_ONELINE	(1<<4)
 #define PRINT_IP_OPT_SRCLINE	(1<<5)
+#define PRINT_IP_OPT_UNKNOWN_AS_ADDR (1<<6)
 
 struct perf_tool;
 

tools/perf/util/symbol.c

@@ -264,8 +264,9 @@ size_t symbol__fprintf(struct symbol *sym, FILE *fp)
 		       sym->name);
 }
 
-size_t symbol__fprintf_symname_offs(const struct symbol *sym,
-				    const struct addr_location *al, FILE *fp)
+size_t __symbol__fprintf_symname_offs(const struct symbol *sym,
+				      const struct addr_location *al,
+				      bool unknown_as_addr, FILE *fp)
 {
 	unsigned long offset;
 	size_t length;
@@ -280,13 +281,29 @@ size_t symbol__fprintf_symname_offs(const struct symbol *sym,
 			length += fprintf(fp, "+0x%lx", offset);
 		}
 		return length;
-	} else
+	} else if (al && unknown_as_addr)
+		return fprintf(fp, "[%#" PRIx64 "]", al->addr);
+	else
 		return fprintf(fp, "[unknown]");
 }
 
+size_t symbol__fprintf_symname_offs(const struct symbol *sym,
+				    const struct addr_location *al,
+				    FILE *fp)
+{
+	return __symbol__fprintf_symname_offs(sym, al, false, fp);
+}
+
+size_t __symbol__fprintf_symname(const struct symbol *sym,
+				 const struct addr_location *al,
+				 bool unknown_as_addr, FILE *fp)
+{
+	return __symbol__fprintf_symname_offs(sym, al, unknown_as_addr, fp);
+}
+
 size_t symbol__fprintf_symname(const struct symbol *sym, FILE *fp)
 {
-	return symbol__fprintf_symname_offs(sym, NULL, fp);
+	return __symbol__fprintf_symname_offs(sym, NULL, false, fp);
 }
 
 void symbols__delete(struct rb_root *symbols)

tools/perf/util/symbol.h

@@ -262,8 +262,14 @@ int symbol__init(struct perf_env *env);
 void symbol__exit(void);
 void symbol__elf_init(void);
 struct symbol *symbol__new(u64 start, u64 len, u8 binding, const char *name);
+size_t __symbol__fprintf_symname_offs(const struct symbol *sym,
+				      const struct addr_location *al,
+				      bool unknown_as_addr, FILE *fp);
 size_t symbol__fprintf_symname_offs(const struct symbol *sym,
 				    const struct addr_location *al, FILE *fp);
+size_t __symbol__fprintf_symname(const struct symbol *sym,
+				 const struct addr_location *al,
+				 bool unknown_as_addr, FILE *fp);
 size_t symbol__fprintf_symname(const struct symbol *sym, FILE *fp);
 size_t symbol__fprintf(struct symbol *sym, FILE *fp);
 bool symbol_type__is_a(char symbol_type, enum map_type map_type);