diff mbox series

[v3,1/3] linux-user: Split out die_with_signal

Message ID 20230822203415.1184491-2-richard.henderson@linaro.org
State Superseded
Headers show
Series linux-user: Detect and report host crashes | expand

Commit Message

Richard Henderson Aug. 22, 2023, 8:34 p.m. UTC 
Because we trap so many signals for use by the guest,
we have to take extra steps to exit properly.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 linux-user/signal.c | 52 ++++++++++++++++++++++++---------------------
 1 file changed, 28 insertions(+), 24 deletions(-)

Comments

Philippe Mathieu-Daudé Aug. 22, 2023, 10:08 p.m. UTC | #1 
On 22/8/23 22:34, Richard Henderson wrote:
> Because we trap so many signals for use by the guest,
> we have to take extra steps to exit properly.
> 
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>   linux-user/signal.c | 52 ++++++++++++++++++++++++---------------------
>   1 file changed, 28 insertions(+), 24 deletions(-)

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
diff mbox series

Patch

diff --git a/linux-user/signal.c b/linux-user/signal.c
index 748a98f3e5..e1cd111a1b 100644
--- a/linux-user/signal.c
+++ b/linux-user/signal.c
@@ -694,6 +694,33 @@  void cpu_loop_exit_sigbus(CPUState *cpu, target_ulong addr,
 }
 
 /* abort execution with signal */
+static G_NORETURN
+void die_with_signal(int 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(sig, &act, NULL);
+
+    kill(getpid(), sig);
+
+    /* Make sure the signal isn't masked (reusing the mask inside of act). */
+    sigdelset(&act.sa_mask, sig);
+    sigsuspend(&act.sa_mask);
+
+    /* unreachable */
+    abort();
+}
+
 static G_NORETURN
 void dump_core_and_abort(CPUArchState *cpu_env, int target_sig)
 {
@@ -701,7 +728,6 @@  void dump_core_and_abort(CPUArchState *cpu_env, int target_sig)
     CPUArchState *env = cpu->env_ptr;
     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);
@@ -725,29 +751,7 @@  void dump_core_and_abort(CPUArchState *cpu_env, int target_sig)
     }
 
     preexit_cleanup(cpu_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