From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1L4Me2-0006Ox-O4 for qemu-devel@nongnu.org; Sun, 23 Nov 2008 16:37:30 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1L4Me2-0006Ol-7X for qemu-devel@nongnu.org; Sun, 23 Nov 2008 16:37:30 -0500 Received: from [199.232.76.173] (port=37406 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1L4Me2-0006Oi-1G for qemu-devel@nongnu.org; Sun, 23 Nov 2008 16:37:30 -0500 Received: from [84.20.150.76] (port=38863 helo=narury.org) by monty-python.gnu.org with esmtps (TLS-1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1L4Me1-0005bp-RD for qemu-devel@nongnu.org; Sun, 23 Nov 2008 16:37:30 -0500 Received: from kos.to (localhost.localdomain [127.0.0.1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by narury.org (Postfix) with ESMTP id 944CB3274003 for ; Sun, 23 Nov 2008 23:37:24 +0200 (EET) Date: Sun, 23 Nov 2008 23:37:24 +0200 From: Riku Voipio Message-ID: <20081123213724.GA15889@kos.to> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Subject: [Qemu-devel] [PATCH] linux-user: Proper exit code for uncaught signals Reply-To: qemu-devel@nongnu.org List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org The proper exit code for dieing from an uncaught signal is -. The kernel doesn't allow exit() or _exit() to pass a negative value. To get the proper exit code we need to actually die from an uncaught signal. A default signal handler is installed, we send ourself a signal and we wait for it to arrive. Patch originates from Scratchbox Signed-off-by: Riku Voipio --- linux-user/signal.c | 37 +++++++++++++++++++++++++------------ 1 files changed, 25 insertions(+), 12 deletions(-) diff --git a/linux-user/signal.c b/linux-user/signal.c index e0f6aaf..dac9933 100644 --- a/linux-user/signal.c +++ b/linux-user/signal.c @@ -24,6 +24,7 @@ #include #include #include +#include #include #include "qemu.h" @@ -328,21 +329,33 @@ static inline void free_sigqueue(CPUState *env, struct sigqueue *q) static void __attribute((noreturn)) force_sig(int sig) { int host_sig; + struct sigaction act; host_sig = target_to_host_signal(sig); fprintf(stderr, "qemu: uncaught target signal %d (%s) - exiting\n", sig, strsignal(host_sig)); -#if 1 - _exit(-host_sig); -#else - { - struct sigaction act; - sigemptyset(&act.sa_mask); - act.sa_flags = SA_SIGINFO; - act.sa_sigaction = SIG_DFL; - sigaction(SIGABRT, &act, NULL); - abort(); - } -#endif + + /* The proper exit code for dieing from an uncaught signal is + * -. The kernel doesn't allow exit() or _exit() to pass + * a negative value. To get the proper exit code we need to + * actually die from an uncaught signal. Here the default signal + * handler is installed, we send ourself a signal and we wait for + * it to arrive. */ + sigfillset(&act.sa_mask); + act.sa_handler = SIG_DFL; + sigaction(host_sig, &act, NULL); + + /* For some reason raise(host_sig) doesn't send the signal when + * statically linked on x86-64. */ + kill(getpid(), host_sig); + + /* Make sure the signal isn't masked (just reuse the mask inside + of act) */ + sigdelset(&act.sa_mask, host_sig); + sigsuspend(&act.sa_mask); + + /* unreachable */ + assert(0); + } /* queue a signal so that it will be send to the virtual CPU as soon -- 1.5.6.5 -- "rm -rf" only sounds scary if you don't have backups