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From: Richard Henderson <richard.henderson@linaro.org>
To: qemu-devel@nongnu.org
Cc: "Helge Deller" <deller@gmx.de>,
	"Philippe Mathieu-Daudé" <philmd@linaro.org>
Subject: [PULL 06/14] linux-user: Split out die_with_signal
Date: Wed, 18 Oct 2023 16:31:26 -0700	[thread overview]
Message-ID: <20231018233134.1594292-7-richard.henderson@linaro.org> (raw)
In-Reply-To: <20231018233134.1594292-1-richard.henderson@linaro.org>

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>
---
 linux-user/signal.c | 52 ++++++++++++++++++++++++---------------------
 1 file changed, 28 insertions(+), 24 deletions(-)

diff --git a/linux-user/signal.c b/linux-user/signal.c
index a67ab47d30..b7a2c47837 100644
--- a/linux-user/signal.c
+++ b/linux-user/signal.c
@@ -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
-- 
2.34.1



  parent reply	other threads:[~2023-10-18 23:34 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-10-18 23:31 [PULL 00/14] linux-user patch queue Richard Henderson
2023-10-18 23:31 ` [PULL 01/14] linux-user: Fixes for zero_bss Richard Henderson
2023-10-18 23:31 ` [PULL 02/14] linux-user/mips: fix abort on integer overflow Richard Henderson
2023-10-18 23:31 ` [PULL 03/14] linux-user/sh4: Fix crashes on signal delivery Richard Henderson
2023-10-18 23:31 ` [PULL 04/14] linux-user/elfload: Enable LSX/LASX in HWCAP for LoongArch Richard Henderson
2023-10-18 23:31 ` [PULL 05/14] linux-user: Propagate failure in mmap_reserve_or_unmap back to target_munmap Richard Henderson
2023-10-18 23:31 ` Richard Henderson [this message]
2023-10-18 23:31 ` [PULL 07/14] linux-user: Exit not abort in die_with_backtrace Richard Henderson
2023-10-18 23:31 ` [PULL 08/14] linux-user: Detect and report host crashes Richard Henderson
2023-10-18 23:31 ` [PULL 09/14] linux-user: Only register handlers for core_dump_signal by default Richard Henderson
2023-10-18 23:31 ` [PULL 10/14] linux-user: Map unsupported signals to an out-of-bounds value Richard Henderson
2023-10-18 23:31 ` [PULL 11/14] linux-user: Simplify signal_init Richard Henderson
2023-10-18 23:31 ` [PULL 12/14] linux-user: Split out host_sig{segv,bus}_handler Richard Henderson
2023-10-18 23:31 ` [PULL 13/14] linux-user: Detect and report host SIGILL, SIGFPE, SIGTRAP Richard Henderson
2023-10-18 23:31 ` [PULL 14/14] linux-user: Remap guest SIGABRT Richard Henderson
2023-10-19 18:51 ` [PULL 00/14] linux-user patch queue Stefan Hajnoczi

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