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[v3,32/40] bsd-user/signal.c: handle_pending_signal

Message ID 20220128232805.86191-33-imp@bsdimp.com
State New
Headers show
Series bsd-user: upstream signal implementation | expand

Commit Message

Warner Losh Jan. 28, 2022, 11:27 p.m. UTC 
Handle a queued signal.

Signed-off-by: Stacey Son <sson@FreeBSD.org>
Signed-off-by: Kyle Evans <kevans@freebsd.org>
Signed-off-by: Warner Losh <imp@bsdimp.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
---
 bsd-user/qemu.h   |  7 ++++
 bsd-user/signal.c | 87 +++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 94 insertions(+)
diff mbox series

Patch

diff --git a/bsd-user/qemu.h b/bsd-user/qemu.h
index de20650a00d..02921ac8b3b 100644
--- a/bsd-user/qemu.h
+++ b/bsd-user/qemu.h
@@ -99,6 +99,8 @@  typedef struct TaskState {
      * from multiple threads.)
      */
     int signal_pending;
+    /* True if we're leaving a sigsuspend and sigsuspend_mask is valid. */
+    bool in_sigsuspend;
     /*
      * This thread's signal mask, as requested by the guest program.
      * The actual signal mask of this thread may differ:
@@ -106,6 +108,11 @@  typedef struct TaskState {
      *  + sometimes we block all signals to avoid races
      */
     sigset_t signal_mask;
+    /*
+     * The signal mask imposed by a guest sigsuspend syscall, if we are
+     * currently in the middle of such a syscall
+     */
+    sigset_t sigsuspend_mask;
 
     /* This thread's sigaltstack, if it has one */
     struct target_sigaltstack sigaltstack_used;
diff --git a/bsd-user/signal.c b/bsd-user/signal.c
index dbc13736073..366e047cccc 100644
--- a/bsd-user/signal.c
+++ b/bsd-user/signal.c
@@ -616,6 +616,93 @@  void signal_init(void)
     }
 }
 
+static void handle_pending_signal(CPUArchState *env, int sig,
+                                  struct emulated_sigtable *k)
+{
+    CPUState *cpu = env_cpu(env);
+    TaskState *ts = cpu->opaque;
+    struct target_sigaction *sa;
+    int code;
+    sigset_t set;
+    abi_ulong handler;
+    target_siginfo_t tinfo;
+    target_sigset_t target_old_set;
+
+    trace_user_handle_signal(env, sig);
+
+    k->pending = 0;
+
+    sig = gdb_handlesig(cpu, sig);
+    if (!sig) {
+        sa = NULL;
+        handler = TARGET_SIG_IGN;
+    } else {
+        sa = &sigact_table[sig - 1];
+        handler = sa->_sa_handler;
+    }
+
+    if (do_strace) {
+        print_taken_signal(sig, &k->info);
+    }
+
+    if (handler == TARGET_SIG_DFL) {
+        /*
+         * default handler : ignore some signal. The other are job
+         * control or fatal.
+         */
+        if (sig == TARGET_SIGTSTP || sig == TARGET_SIGTTIN ||
+            sig == TARGET_SIGTTOU) {
+            kill(getpid(), SIGSTOP);
+        } else if (sig != TARGET_SIGCHLD && sig != TARGET_SIGURG &&
+                   sig != TARGET_SIGINFO && sig != TARGET_SIGWINCH &&
+                   sig != TARGET_SIGCONT) {
+            dump_core_and_abort(sig);
+        }
+    } else if (handler == TARGET_SIG_IGN) {
+        /* ignore sig */
+    } else if (handler == TARGET_SIG_ERR) {
+        dump_core_and_abort(sig);
+    } else {
+        /* compute the blocked signals during the handler execution */
+        sigset_t *blocked_set;
+
+        target_to_host_sigset(&set, &sa->sa_mask);
+        /*
+         * SA_NODEFER indicates that the current signal should not be
+         * blocked during the handler.
+         */
+        if (!(sa->sa_flags & TARGET_SA_NODEFER)) {
+            sigaddset(&set, target_to_host_signal(sig));
+        }
+
+        /*
+         * Save the previous blocked signal state to restore it at the
+         * end of the signal execution (see do_sigreturn).
+         */
+        host_to_target_sigset_internal(&target_old_set, &ts->signal_mask);
+
+        blocked_set = ts->in_sigsuspend ?
+            &ts->sigsuspend_mask : &ts->signal_mask;
+        sigorset(&ts->signal_mask, blocked_set, &set);
+        ts->in_sigsuspend = false;
+        sigprocmask(SIG_SETMASK, &ts->signal_mask, NULL);
+
+        /* XXX VM86 on x86 ??? */
+
+        code = k->info.si_code; /* From host, so no si_type */
+        /* prepare the stack frame of the virtual CPU */
+        if (sa->sa_flags & TARGET_SA_SIGINFO) {
+            tswap_siginfo(&tinfo, &k->info);
+            setup_frame(sig, code, sa, &target_old_set, &tinfo, env);
+        } else {
+            setup_frame(sig, code, sa, &target_old_set, NULL, env);
+        }
+        if (sa->sa_flags & TARGET_SA_RESETHAND) {
+            sa->_sa_handler = TARGET_SIG_DFL;
+        }
+    }
+}
+
 void process_pending_signals(CPUArchState *cpu_env)
 {
 }