Commit 701677b9 authored by Ian Rogers's avatar Ian Rogers Committed by Arnaldo Carvalho de Melo
Browse files

perf srcline: Add a timeout to reading from addr2line 



addr2line may fail to send expected values causing perf to wait
indefinitely. Add a 1 second timeout (twice the timeout for reading from
/proc/pid/maps) so that such reads don't cause perf to appear to lock
up.

There are already checks that the file for addr2line contains a debug
section but this isn't always sufficient. The problem was observed when
a valid elf file would set the configuration for binutils addr2line,
then a later read of vmlinux with ELF debug sections would cause a
failing write/read which would block indefinitely.

As a service to future readers, if the io hits eof or an error, cleanup
the addr2line process.

Signed-off-by: default avatarIan Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Yang Jihong <yangjihong1@huawei.com>
Link: https://lore.kernel.org/r/20230608061812.3715566-2-irogers@google.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent f4c0d530

tools/perf/util/config.c

+5 −2
Original line number Diff line number Diff line
@@ -19,6 +19,7 @@ 
#include "util/llvm-utils.h"   /* perf_llvm_config */

#include "util/stat.h"  /* perf_stat__set_big_num */

#include "util/evsel.h"  /* evsel__hw_names, evsel__use_bpf_counters */

#include "util/srcline.h"  /* addr2line_timeout_ms */

#include "build-id.h"

#include "debug.h"

#include "config.h"
@@ -434,12 +435,14 @@ static int perf_buildid_config(const char *var, const char *value) 
	return 0;

}



static int perf_default_core_config(const char *var __maybe_unused,

				    const char *value __maybe_unused)

static int perf_default_core_config(const char *var, const char *value)

{

	if (!strcmp(var, "core.proc-map-timeout"))

		proc_map_timeout = strtoul(value, NULL, 10);



	if (!strcmp(var, "core.addr2line-timeout"))

		addr2line_timeout_ms = strtoul(value, NULL, 10);



	/* Add other config variables here. */

	return 0;

}

tools/perf/util/srcline.c

+8 −2
Original line number Diff line number Diff line
@@ -21,6 +21,8 @@ 
#include "symbol.h"

#include "subcmd/run-command.h"



/* If addr2line doesn't return data for 1 second then timeout. */

int addr2line_timeout_ms = 1 * 1000;

bool srcline_full_filename;



char *srcline__unknown = (char *)"??:0";
@@ -631,7 +633,7 @@ static int addr2line(const char *dso_name, u64 addr, 
	int len;

	char buf[128];

	ssize_t written;

	struct io io;

	struct io io = { .eof = false };

	enum a2l_style a2l_style;



	if (!a2l) {
@@ -670,7 +672,7 @@ static int addr2line(const char *dso_name, u64 addr, 
		goto out;

	}

	io__init(&io, a2l->out, buf, sizeof(buf));



	io.timeout_ms = addr2line_timeout_ms;

	switch (read_addr2line_record(&io, a2l_style,

				      &record_function, &record_filename, &record_line_nr)) {

	case -1:
@@ -741,6 +743,10 @@ static int addr2line(const char *dso_name, u64 addr, 
out:

	free(record_function);

	free(record_filename);

	if (io.eof) {

		dso->a2l = NULL;

		addr2line_subprocess_cleanup(a2l);

	}

	return ret;

}

tools/perf/util/srcline.h

+1 −0
Original line number Diff line number Diff line
@@ -9,6 +9,7 @@ 
struct dso;

struct symbol;



extern int addr2line_timeout_ms;

extern bool srcline_full_filename;

char *get_srcline(struct dso *dso, u64 addr, struct symbol *sym,

		  bool show_sym, bool show_addr, u64 ip);