From 3674838cd05268954bb6473239cd7f700a79bf0f Mon Sep 17 00:00:00 2001 From: Luiz Capitulino Date: Mon, 14 May 2012 15:25:20 -0300 Subject: qemu-ga: guest-shutdown: use only async-signal-safe functions POSIX mandates[1] that a child process of a multi-thread program uses only async-signal-safe functions before exec(). We consider qemu-ga to be multi-thread, because it uses glib. However, qmp_guest_shutdown() uses functions that are not async-signal-safe. Fix it the following way: - fclose() -> reopen_fd_to_null() - execl() -> execle() - exit() -> _exit() - drop slog() usage (which is not safe) [1] http://pubs.opengroup.org/onlinepubs/009695399/functions/fork.html Signed-off-by: Luiz Capitulino Reviewed-by: Eric Blake Signed-off-by: Michael Roth --- qga/commands-posix.c | 19 ++++++++----------- 1 file changed, 8 insertions(+), 11 deletions(-) (limited to 'qga') diff --git a/qga/commands-posix.c b/qga/commands-posix.c index 68da71f232..7664be10a0 100644 --- a/qga/commands-posix.c +++ b/qga/commands-posix.c @@ -37,8 +37,8 @@ void qmp_guest_shutdown(bool has_mode, const char *mode, Error **err) { const char *shutdown_flag; - int ret, status; pid_t rpid, pid; + int status; slog("guest-shutdown called, mode: %s", mode); if (!has_mode || strcmp(mode, "powerdown") == 0) { @@ -57,16 +57,13 @@ void qmp_guest_shutdown(bool has_mode, const char *mode, Error **err) if (pid == 0) { /* child, start the shutdown */ setsid(); - fclose(stdin); - fclose(stdout); - fclose(stderr); - - ret = execl("/sbin/shutdown", "shutdown", shutdown_flag, "+0", - "hypervisor initiated shutdown", (char*)NULL); - if (ret) { - slog("guest-shutdown failed: %s", strerror(errno)); - } - exit(!!ret); + reopen_fd_to_null(0); + reopen_fd_to_null(1); + reopen_fd_to_null(2); + + execle("/sbin/shutdown", "shutdown", shutdown_flag, "+0", + "hypervisor initiated shutdown", (char*)NULL, environ); + _exit(EXIT_FAILURE); } else if (pid < 0) { goto exit_err; } -- cgit v1.2.1