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linux-user: Split out die_with_signal

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Because we trap so many signals for use by the guest,
we have to take extra steps to exit properly.

Acked-by: Helge Deller <deller@gmx.de>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This commit is contained in:
Richard Henderson 2023-08-22 12:53:19 -07:00
parent 912ff698ca
commit b8b50f1e9a
1 changed files with 28 additions and 24 deletions
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52
linux-user/signal.c
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@ -689,13 +689,39 @@ void cpu_loop_exit_sigbus(CPUState *cpu, target_ulong addr,
}
/* abort execution with signal */
static G_NORETURN
void die_with_signal(int host_sig)
{
struct sigaction act = {
.sa_handler = SIG_DFL,
};
/*
* The proper exit code for dying from an uncaught signal is -<signal>.
* 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
* the signal and we wait for it to arrive.
*/
sigfillset(&act.sa_mask);
sigaction(host_sig, &act, NULL);
kill(getpid(), host_sig);
/* Make sure the signal isn't masked (reusing the mask inside of act). */
sigdelset(&act.sa_mask, host_sig);
sigsuspend(&act.sa_mask);
/* unreachable */
abort();
}
static G_NORETURN
void dump_core_and_abort(CPUArchState *env, int target_sig)
{
CPUState *cpu = env_cpu(env);
TaskState *ts = (TaskState *)cpu->opaque;
int host_sig, core_dumped = 0;
struct sigaction act;
host_sig = target_to_host_signal(target_sig);
trace_user_dump_core_and_abort(env, target_sig, host_sig);
@ -719,29 +745,7 @@ void dump_core_and_abort(CPUArchState *env, int target_sig)
}
preexit_cleanup(env, 128 + target_sig);
/* The proper exit code for dying from an uncaught signal is
* -<signal>. 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;
act.sa_flags = 0;
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 */
abort();
die_with_signal(host_sig);
}
/* queue a signal so that it will be send to the virtual CPU as soon