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: Ian 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: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/tools/perf/util/srcline.h b/tools/perf/util/srcline.h
index 167645bcff07..75010d39ea28 100644
--- a/tools/perf/util/srcline.h
+++ b/tools/perf/util/srcline.h
@@ -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);