From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1L5fsZ-0002fy-DJ for qemu-devel@nongnu.org; Thu, 27 Nov 2008 07:21:55 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1L5fsX-0002fE-JR for qemu-devel@nongnu.org; Thu, 27 Nov 2008 07:21:54 -0500 Received: from [199.232.76.173] (port=34624 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1L5fsX-0002fB-GA for qemu-devel@nongnu.org; Thu, 27 Nov 2008 07:21:53 -0500 Received: from [84.20.150.76] (port=32792 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 1L5fsW-0005KU-VT for qemu-devel@nongnu.org; Thu, 27 Nov 2008 07:21:53 -0500 Date: Thu, 27 Nov 2008 14:21:44 +0200 From: Riku Voipio Subject: Re: [Qemu-devel] [PATCH] linux-user: Proper exit code for uncaught signals Message-ID: <20081127122144.GA5905@kos.to> References: <20081123213724.GA15889@kos.to> <20081127114233.GC15592@networkno.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20081127114233.GC15592@networkno.de> Reply-To: qemu-devel@nongnu.org List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Thiemo Seufer Cc: qemu-devel@nongnu.org, lauro.venancio@openbossa.org On Thu, Nov 27, 2008 at 12:42:33PM +0100, Thiemo Seufer wrote: > Riku Voipio wrote: > > 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 > > So, who holds the copyright (and deserves the credit)? The qemu tarball[1] provided on scratchbox site doesn't document who wrote patches and who has the copyright. Most likely a contractor for Nokia wrote it, and the copyright is Nokia's. Lauro might know as the patch is also at the qemu-arm-eabi sf project site. [1] http://scratchbox.org/download/files/sbox-releases/stable/src/scratchbox-devkit-cputransp-qemu-arm-cvs-m-1.0.7/qemu-arm-0108.tar.gz > Thiemo > > > 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 > > -- "rm -rf" only sounds scary if you don't have backups