perf record: Disable debuginfod by default

Fedora 35 sets DEBUGINFOD_URLS by default, which might lead to
unexpected stalls in perf record exit path, when we try to cache
profiled binaries.

  # DEBUGINFOD_PROGRESS=1 ./perf record -a
  ^C[ perf record: Woken up 1 times to write data ]
  Downloading from https://debuginfod.fedoraproject.org/ 447069
  Downloading from https://debuginfod.fedoraproject.org/ 1502175
  Downloading \^Z

Disabling DEBUGINFOD_URLS by default in perf record and adding
debuginfod option and .perfconfig variable support to enable id.

  Default without debuginfo processing:
  # perf record -a

  Using system debuginfod setup:
  # perf record -a --debuginfod

  Using custom debuginfd url:
  # perf record -a --debuginfod='https://evenbetterdebuginfodserver.krava'

Adding single perf_debuginfod_setup function and using
it also in perf buildid-cache command.

Signed-off-by: Jiri Olsa <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Frank Ch. Eigler <[email protected]>
Cc: Ian Rogers <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Michael Petlan <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Link: http://lore.kernel.org/lkml/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

1 files changed, 15 insertions, 0 deletions

diff --git a/tools/perf/util/util.c b/tools/perf/util/util.c
index df3c4671be72..fb4f6616b5fa 100644
--- a/tools/perf/util/util.c
+++ b/tools/perf/util/util.c
@@ -416,3 +416,18 @@ char *perf_exe(char *buf, int len)
 	}
 	return strcpy(buf, "perf");
 }
+
+void perf_debuginfod_setup(struct perf_debuginfod *di)
+{
+	/*
+	 * By default '!di->set' we clear DEBUGINFOD_URLS, so debuginfod
+	 * processing is not triggered, otherwise we set it to 'di->urls'
+	 * value. If 'di->urls' is "system" we keep DEBUGINFOD_URLS value.
+	 */
+	if (!di->set)
+		setenv("DEBUGINFOD_URLS", "", 1);
+	else if (di->urls && strcmp(di->urls, "system"))
+		setenv("DEBUGINFOD_URLS", di->urls, 1);
+
+	pr_debug("DEBUGINFOD_URLS=%s\n", getenv("DEBUGINFOD_URLS"));
+}