From 40db8ff59e75af108d695597bdbaa4828e129178 Mon Sep 17 00:00:00 2001
From: Adrian Hunter <adrian.hunter@intel.com>
Date: Tue, 1 Sep 2020 12:37:54 +0300
Subject: [PATCH] perf tools: Handle read errors from ctl_fd
Handle read errors from ctl_fd such as EINTR, EAGAIN and EWOULDBLOCK.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Alexey Budankov <alexey.budankov@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lore.kernel.org/lkml/20200901093758.32293-3-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
tools/perf/util/evlist.c | 16 +++++++++++-----
1 file changed, 11 insertions(+), 5 deletions(-)
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index 62e3f87547ce0b..47d1045a19af50 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -1802,6 +1802,7 @@ static int evlist__ctlfd_recv(struct evlist *evlist, enum evlist_ctl_cmd *cmd,
char c;
size_t bytes_read = 0;
+ *cmd = EVLIST_CTL_CMD_UNSUPPORTED;
memset(cmd_data, 0, data_size);
data_size--;
@@ -1813,17 +1814,22 @@ static int evlist__ctlfd_recv(struct evlist *evlist, enum evlist_ctl_cmd *cmd,
cmd_data[bytes_read++] = c;
if (bytes_read == data_size)
break;
- } else {
- if (err == -1)
+ continue;
+ } else if (err == -1) {
+ if (errno == EINTR)
+ continue;
+ if (errno == EAGAIN || errno == EWOULDBLOCK)
+ err = 0;
+ else
pr_err("Failed to read from ctlfd %d: %m\n", evlist->ctl_fd.fd);
- break;
}
+ break;
} while (1);
pr_debug("Message from ctl_fd: \"%s%s\"\n", cmd_data,
bytes_read == data_size ? "" : c == '\n' ? "\\n" : "\\0");
- if (err > 0) {
+ if (bytes_read > 0) {
if (!strncmp(cmd_data, EVLIST_CTL_CMD_ENABLE_TAG,
(sizeof(EVLIST_CTL_CMD_ENABLE_TAG)-1))) {
*cmd = EVLIST_CTL_CMD_ENABLE;
@@ -1833,7 +1839,7 @@ static int evlist__ctlfd_recv(struct evlist *evlist, enum evlist_ctl_cmd *cmd,
}
}
- return err;
+ return bytes_read ? (int)bytes_read : err;
}
static int evlist__ctlfd_ack(struct evlist *evlist)
--
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