The Linux 3.14 release adds support for the PERF_FLAG_FD_CLOEXEC flag to perf_event_open.2 This version tries to clarify that the close-on-exec behavior applies to the current file descriptor being created. The wording is based on the description in kernel commit a21b0b354d4ac39be691f51c53562e2c24443d9e by Yann Droneaud <ydroneaud@xxxxxxxxxx> Signed-off-by: Vince Weaver <vincent.weaver@xxxxxxxxx> diff --git a/man2/perf_event_open.2 b/man2/perf_event_open.2 index 30a2168..b4a49c4 100644 --- a/man2/perf_event_open.2 +++ b/man2/perf_event_open.2 @@ -164,6 +164,19 @@ must be passed as the parameter. cgroup monitoring is available only for system-wide events and may therefore require extra permissions. +.TP +.BR PERF_FLAG_FD_CLOEXEC " (since Linux 3.14)." +This flag enables close-on-exec behavior for the created +event file descriptor, removing it from the list of +file descriptors inherited across exec. +Setting this behavior atomically at creation time rather than +later with +.BR fctl (2) +avoids potential race conditions between the current thread and +another calling +.BR fork (2) +then +.BR execve(2). .P The .I perf_event_attr -- To unsubscribe from this list: send the line "unsubscribe linux-man" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
