From 8ae2c6300feffc598f1b13b9268e7312c647d19e Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Wed, 19 Oct 2016 23:30:50 +0200 Subject: journald,core: add short comments we we keep reopening /dev/console all the time Just to make sure the next one reading this isn't surprised that the fd isn't kept open. SAK and stuff... Fix suggested: https://github.com/systemd/systemd/pull/4366#issuecomment-253659162 --- src/core/show-status.c | 5 +++++ src/journal/journald-console.c | 5 +++++ 2 files changed, 10 insertions(+) (limited to 'src') diff --git a/src/core/show-status.c b/src/core/show-status.c index 59ebdc7219..65f9cb888a 100644 --- a/src/core/show-status.c +++ b/src/core/show-status.c @@ -61,6 +61,11 @@ int status_vprintf(const char *status, bool ellipse, bool ephemeral, const char if (vasprintf(&s, format, ap) < 0) return log_oom(); + /* Before you ask: yes, on purpose we open/close the console for each status line we write individually. This + * is a good strategy to avoid PID 1 getting killed by the kernel's SAK concept (it doesn't fix this entirely, + * but minimizes the time window the kernel might end up killing PID 1 due to SAK). It also makes things easier + * for us so that we don't have to recover from hangups and suchlike triggered on the console. */ + fd = open_terminal("/dev/console", O_WRONLY|O_NOCTTY|O_CLOEXEC); if (fd < 0) return fd; diff --git a/src/journal/journald-console.c b/src/journal/journald-console.c index fcc9f25814..3a9fba42a3 100644 --- a/src/journal/journald-console.c +++ b/src/journal/journald-console.c @@ -102,6 +102,11 @@ void server_forward_console( tty = s->tty_path ? s->tty_path : "/dev/console"; + /* Before you ask: yes, on purpose we open/close the console for each log line we write individually. This is a + * good strategy to avoid journald getting killed by the kernel's SAK concept (it doesn't fix this entirely, + * but minimizes the time window the kernel might end up killing journald due to SAK). It also makes things + * easier for us so that we don't have to recover from hangups and suchlike triggered on the console. */ + fd = open_terminal(tty, O_WRONLY|O_NOCTTY|O_CLOEXEC); if (fd < 0) { log_debug_errno(fd, "Failed to open %s for logging: %m", tty); -- cgit v1.2.3-54-g00ecf