From: Adrian Hunter Date: Tue, 1 Sep 2020 09:37:54 +0000 (+0300) Subject: perf tools: Handle read errors from ctl_fd X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=40db8ff59e75af108d695597bdbaa4828e129178;p=linux.git 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 Acked-by: Alexey Budankov Acked-by: Jiri Olsa Cc: Andi Kleen Cc: Namhyung Kim Link: http://lore.kernel.org/lkml/20200901093758.32293-3-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo --- diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c index 62e3f87547ce0..47d1045a19af5 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)