From: Richard Henderson <richard.henderson@linaro.org>
To: qemu-devel@nongnu.org
Cc: deller@gmx.de
Subject: [PATCH v4 08/10] linux-user: Simplify signal_init
Date: Tue, 22 Aug 2023 22:16:13 -0700 [thread overview]
Message-ID: <20230823051615.1297706-9-richard.henderson@linaro.org> (raw)
In-Reply-To: <20230823051615.1297706-1-richard.henderson@linaro.org>
Install the host signal handler at the same time we are
probing the target signals for SIG_IGN/SIG_DFL. Ignore
unmapped target signals.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
linux-user/signal.c | 47 +++++++++++++++++++++------------------------
1 file changed, 22 insertions(+), 25 deletions(-)
diff --git a/linux-user/signal.c b/linux-user/signal.c
index b8913968cc..a6917eadd8 100644
--- a/linux-user/signal.c
+++ b/linux-user/signal.c
@@ -566,10 +566,7 @@ static void signal_table_init(void)
void signal_init(void)
{
TaskState *ts = (TaskState *)thread_cpu->opaque;
- struct sigaction act;
- struct sigaction oact;
- int i;
- int host_sig;
+ struct sigaction act, oact;
/* initialize signal conversion tables */
signal_table_init();
@@ -580,28 +577,28 @@ void signal_init(void)
sigfillset(&act.sa_mask);
act.sa_flags = SA_SIGINFO;
act.sa_sigaction = host_signal_handler;
- for(i = 1; i <= TARGET_NSIG; i++) {
-#ifdef CONFIG_GPROF
- if (i == TARGET_SIGPROF) {
- continue;
- }
-#endif
- host_sig = target_to_host_signal(i);
- sigaction(host_sig, NULL, &oact);
- if (oact.sa_sigaction == (void *)SIG_IGN) {
- sigact_table[i - 1]._sa_handler = TARGET_SIG_IGN;
- } else if (oact.sa_sigaction == (void *)SIG_DFL) {
- sigact_table[i - 1]._sa_handler = TARGET_SIG_DFL;
- }
- /* If there's already a handler installed then something has
- gone horribly wrong, so don't even try to handle that case. */
- /* Install some handlers for our own use. We need at least
- SIGSEGV and SIGBUS, to detect exceptions. We can not just
- trap all signals because it affects syscall interrupt
- behavior. But do trap all default-fatal signals. */
- if (core_dump_signal(i)) {
- sigaction(host_sig, &act, NULL);
+
+ /*
+ * A parent process may configure ignored signals, but all other
+ * signals are default. For any target signals that have no host
+ * mapping, set to ignore. For all core_dump_signal, install our
+ * host signal handler so that we may invoke dump_core_and_abort.
+ * This includes SIGSEGV and SIGBUS, which are also need our signal
+ * handler for paging and exceptions.
+ */
+ for (int tsig = 1; tsig <= TARGET_NSIG; tsig++) {
+ int hsig = target_to_host_signal(tsig);
+ abi_ptr thand = TARGET_SIG_IGN;
+
+ if (hsig < _NSIG) {
+ struct sigaction *iact = core_dump_signal(tsig) ? &act : NULL;
+
+ sigaction(hsig, iact, &oact);
+ if (oact.sa_sigaction != (void *)SIG_IGN) {
+ thand = TARGET_SIG_DFL;
+ }
}
+ sigact_table[tsig - 1]._sa_handler = thand;
}
}
--
2.34.1
next prev parent reply other threads:[~2023-08-23 5:18 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-08-23 5:16 [PATCH v4 00/10] linux-user: Detect and report host crashes Richard Henderson
2023-08-23 5:16 ` [PATCH v4 01/10] linux-user: Split out die_with_signal Richard Henderson
2023-08-23 12:55 ` Philippe Mathieu-Daudé
2023-08-23 5:16 ` [PATCH v4 02/10] linux-user: Exit not abort in die_with_backtrace Richard Henderson
2023-08-23 12:55 ` Philippe Mathieu-Daudé
2023-08-23 5:16 ` [PATCH v4 03/10] linux-user: Use die_with_signal with abort Richard Henderson
2023-08-23 5:16 ` [PATCH v4 04/10] linux-user: Detect and report host crashes Richard Henderson
2023-08-23 5:16 ` [PATCH v4 05/10] linux-user: Only register handlers for core_dump_signal by default Richard Henderson
2023-08-23 5:16 ` [PATCH v4 06/10] linux-user: Map unsupported signals to an out-of-bounds value Richard Henderson
2023-08-23 5:16 ` [PATCH v4 07/10] linux-user: Remap SIGPROF when CONFIG_GPROF Richard Henderson
2023-08-23 5:16 ` Richard Henderson [this message]
2023-08-23 5:16 ` [PATCH v4 09/10] linux-user: Split out host_sig{segv,bus}_handler Richard Henderson
2023-08-23 5:16 ` [PATCH v4 10/10] linux-user: Detect and report host SIGILL, SIGFPE, SIGTRAP Richard Henderson
2023-09-09 19:12 ` [PATCH v4 00/10] linux-user: Detect and report host crashes Richard Henderson
2023-09-12 9:45 ` Helge Deller
2023-09-12 10:34 ` Michael Tokarev
2023-09-18 14:05 ` Helge Deller
2023-09-19 7:40 ` Michael Tokarev
2023-09-19 8:00 ` Helge Deller
2023-09-19 8:26 ` Michael Tokarev
2023-09-19 8:38 ` Richard Henderson
2023-09-19 9:17 ` Helge Deller
2023-09-19 13:01 ` Michael Tokarev
2023-09-19 8:29 ` Richard Henderson
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