path: root/static/netbsd/man9/signal.9 3.html

<table class="head">
  <tr>
    <td class="head-ltitle">SIGNAL(9)</td>
    <td class="head-vol">Kernel Developer's Manual</td>
    <td class="head-rtitle">SIGNAL(9)</td>
  </tr>
</table>
<div class="manual-text">
<section class="Sh">
<h1 class="Sh" id="NAME"><a class="permalink" href="#NAME">NAME</a></h1>
<p class="Pp"><code class="Nm">signal</code>, <code class="Nm">siginit</code>,
    <code class="Nm">sigactsinit</code>, <code class="Nm">sigactsunshare</code>,
    <code class="Nm">sigactsfree</code>, <code class="Nm">execsigs</code>,
    <code class="Nm">sigaction1</code>, <code class="Nm">sigprocmask1</code>,
    <code class="Nm">sigpending1</code>, <code class="Nm">sigsuspend1</code>,
    <code class="Nm">sigaltstack1</code>, <code class="Nm">pgsignal</code>,
    <code class="Nm">kpgsignal</code>, <code class="Nm">psignal</code>,
    <code class="Nm">kpsignal</code>, <code class="Nm">issignal</code>,
    <code class="Nm">postsig</code>, <code class="Nm">killproc</code>,
    <code class="Nm">sigexit</code>, <code class="Nm">trapsignal</code>,
    <code class="Nm">sendsig</code>, <code class="Nm">sigcode</code>,
    <code class="Nm">sigtramp</code> &#x2014; <span class="Nd">software signal
    facilities</span></p>
</section>
<section class="Sh">
<h1 class="Sh" id="SYNOPSIS"><a class="permalink" href="#SYNOPSIS">SYNOPSIS</a></h1>
<p class="Pp"><code class="In">#include
    &lt;<a class="In">sys/signal.h</a>&gt;</code>
  <br/>
  <code class="In">#include &lt;<a class="In">sys/signalvar.h</a>&gt;</code></p>
<p class="Pp"><var class="Ft">void</var>
  <br/>
  <code class="Fn">siginit</code>(<var class="Fa" style="white-space: nowrap;">struct
    proc *p</var>);</p>
<p class="Pp"><var class="Ft">void</var>
  <br/>
  <code class="Fn">sigactsinit</code>(<var class="Fa" style="white-space: nowrap;">struct
    proc *pp</var>, <var class="Fa" style="white-space: nowrap;">int
    share</var>);</p>
<p class="Pp"><var class="Ft">void</var>
  <br/>
  <code class="Fn">sigactsunshare</code>(<var class="Fa" style="white-space: nowrap;">struct
    proc *p</var>);</p>
<p class="Pp"><var class="Ft">void</var>
  <br/>
  <code class="Fn">sigactsfree</code>(<var class="Fa" style="white-space: nowrap;">struct
    proc *p</var>);</p>
<p class="Pp"><var class="Ft">void</var>
  <br/>
  <code class="Fn">execsigs</code>(<var class="Fa" style="white-space: nowrap;">struct
    proc *p</var>);</p>
<p class="Pp"><var class="Ft">int</var>
  <br/>
  <code class="Fn">sigaction1</code>(<var class="Fa" style="white-space: nowrap;">struct
    lwp *l</var>, <var class="Fa" style="white-space: nowrap;">int signum</var>,
    <var class="Fa" style="white-space: nowrap;">const struct sigaction
    *nsa</var>, <var class="Fa" style="white-space: nowrap;">struct sigaction
    *osa</var>, <var class="Fa" style="white-space: nowrap;">void *tramp</var>,
    <var class="Fa" style="white-space: nowrap;">int vers</var>);</p>
<p class="Pp"><var class="Ft">int</var>
  <br/>
  <code class="Fn">sigprocmask1</code>(<var class="Fa" style="white-space: nowrap;">struct
    lwp *l</var>, <var class="Fa" style="white-space: nowrap;">int how</var>,
    <var class="Fa" style="white-space: nowrap;">const sigset_t *nss</var>,
    <var class="Fa" style="white-space: nowrap;">sigset_t *oss</var>);</p>
<p class="Pp"><var class="Ft">void</var>
  <br/>
  <code class="Fn">sigpending1</code>(<var class="Fa" style="white-space: nowrap;">struct
    lwp *l</var>, <var class="Fa" style="white-space: nowrap;">sigset_t
    *ss</var>);</p>
<p class="Pp"><var class="Ft">int</var>
  <br/>
  <code class="Fn">sigsuspend1</code>(<var class="Fa" style="white-space: nowrap;">struct
    lwp *l</var>, <var class="Fa" style="white-space: nowrap;">const sigset_t
    *ss</var>);</p>
<p class="Pp"><var class="Ft">int</var>
  <br/>
  <code class="Fn">sigaltstack1</code>(<var class="Fa" style="white-space: nowrap;">struct
    lwp *l</var>, <var class="Fa" style="white-space: nowrap;">const struct
    sigaltstack *nss</var>, <var class="Fa" style="white-space: nowrap;">struct
    sigaltstack *oss</var>);</p>
<p class="Pp"><var class="Ft">void</var>
  <br/>
  <code class="Fn">pgsignal</code>(<var class="Fa" style="white-space: nowrap;">struct
    pgrp *pgrp</var>, <var class="Fa" style="white-space: nowrap;">int
    signum</var>, <var class="Fa" style="white-space: nowrap;">int
    checkctty</var>);</p>
<p class="Pp"><var class="Ft">void</var>
  <br/>
  <code class="Fn">kpgsignal</code>(<var class="Fa" style="white-space: nowrap;">struct
    pgrp *pgrp</var>, <var class="Fa" style="white-space: nowrap;">ksiginfo_t
    *ks</var>, <var class="Fa" style="white-space: nowrap;">void *data</var>,
    <var class="Fa" style="white-space: nowrap;">int checkctty</var>);</p>
<p class="Pp"><var class="Ft">void</var>
  <br/>
  <code class="Fn">psignal</code>(<var class="Fa" style="white-space: nowrap;">struct
    proc *p</var>, <var class="Fa" style="white-space: nowrap;">int
    signum</var>);</p>
<p class="Pp"><var class="Ft">void</var>
  <br/>
  <code class="Fn">kpsignal</code>(<var class="Fa" style="white-space: nowrap;">struct
    proc *p</var>, <var class="Fa" style="white-space: nowrap;">ksiginfo_t
    *ks</var>, <var class="Fa" style="white-space: nowrap;">void
  *data</var>);</p>
<p class="Pp"><var class="Ft">int</var>
  <br/>
  <code class="Fn">issignal</code>(<var class="Fa" style="white-space: nowrap;">struct
    lwp *l</var>);</p>
<p class="Pp"><var class="Ft">void</var>
  <br/>
  <code class="Fn">postsig</code>(<var class="Fa" style="white-space: nowrap;">int
    signum</var>);</p>
<p class="Pp"><var class="Ft">void</var>
  <br/>
  <code class="Fn">killproc</code>(<var class="Fa" style="white-space: nowrap;">struct
    proc *p</var>, <var class="Fa" style="white-space: nowrap;">const char
    *why</var>);</p>
<p class="Pp"><var class="Ft">void</var>
  <br/>
  <code class="Fn">sigexit</code>(<var class="Fa" style="white-space: nowrap;">struct
    lwp *l</var>, <var class="Fa" style="white-space: nowrap;">int
    signum</var>);</p>
<p class="Pp"><var class="Ft">void</var>
  <br/>
  <code class="Fn">trapsignal</code>(<var class="Fa" style="white-space: nowrap;">struct
    lwp *l</var>, <var class="Fa" style="white-space: nowrap;">const ksiginfo_t
    *ks</var>);</p>
<p class="Pp"><var class="Ft">void</var>
  <br/>
  <code class="Fn">sendsig</code>(<var class="Fa" style="white-space: nowrap;">const
    ksiginfo_t *ks</var>, <var class="Fa" style="white-space: nowrap;">const
    sigset_t *mask</var>);</p>
</section>
<section class="Sh">
<h1 class="Sh" id="DESCRIPTION"><a class="permalink" href="#DESCRIPTION">DESCRIPTION</a></h1>
<p class="Pp">The system defines a set of signals that may be delivered to a
    process. These functions implement the kernel portion of the signal
    facility.</p>
<p class="Pp">Signal numbers used throughout the kernel signal facilities should
    always be within the range of [1-NSIG].</p>
<p class="Pp">Most of the kernel's signal infrastructure is implemented in
    machine-independent code. Machine-dependent code provides support for
    invoking a process's signal handler, restoring context when the signal
    handler returns, generating signals when hardware traps occur, triggering
    the delivery of signals when a process is about to return from the kernel to
    userspace.</p>
<p class="Pp">The signal state for a process is contained in
    <var class="Fa">struct sigctx</var>. This includes the list of signals with
    delivery pending, information about the signal handler stack, the signal
    mask, and the address of the signal trampoline.</p>
<p class="Pp">The registered signal handlers for a process are recorded in
    <var class="Fa">struct sigacts</var>. This structure may be shared by
    multiple processes.</p>
<p class="Pp">The kernel's signal facilities are implemented by the following
    functions:</p>
<dl class="Bl-tag">
  <dt id="siginit"><a class="permalink" href="#siginit"><code class="Fn">siginit</code></a>(<var class="Fa">p</var>)</dt>
  <dd>
    <p class="Pp">This function initializes the signal state of
        <var class="Va">proc0</var> to the system default. This signal state is
        then inherited by <a class="Xr">init(8)</a> when it is started by the
        kernel.</p>
  </dd>
  <dt id="sigactsinit"><a class="permalink" href="#sigactsinit"><code class="Fn">sigactsinit</code></a>(<var class="Fa">pp</var>,
    <var class="Fa">share</var>)</dt>
  <dd>
    <p class="Pp">This function creates an initial <var class="Fa">struct
        sigacts</var> for the process <var class="Fa">pp</var>. If the
        <var class="Fa">share</var> argument is non-zero, then
        <var class="Fa">pp</var> shares the <var class="Fa">struct sigacts</var>
        by holding a reference. Otherwise, <var class="Fa">pp</var> receives a
        new <var class="Fa">struct sigacts</var> which is copied from the
        parent.</p>
  </dd>
  <dt id="sigactsunshare"><a class="permalink" href="#sigactsunshare"><code class="Fn">sigactsunshare</code></a>(<var class="Fa">p</var>)</dt>
  <dd>
    <p class="Pp">This function causes the process <var class="Fa">p</var> to no
        longer share its <var class="Fa">struct sigacts</var> The current state
        of the signal actions is maintained in the new copy.</p>
  </dd>
  <dt id="sigactsfree"><a class="permalink" href="#sigactsfree"><code class="Fn">sigactsfree</code></a>(<var class="Fa">p</var>)</dt>
  <dd>
    <p class="Pp">This function decrements the reference count on the
        <var class="Fa">struct sigacts</var> of process <var class="Fa">p</var>.
        If the reference count reaches zero, the <var class="Fa">struct
        sigacts</var> is freed.</p>
  </dd>
  <dt id="execsigs"><a class="permalink" href="#execsigs"><code class="Fn">execsigs</code></a>(<var class="Fa">p</var>)</dt>
  <dd>
    <p class="Pp">This function is used to reset the signal state of the process
        <var class="Fa">p</var> to the system defaults when the process execs a
        new program image.</p>
  </dd>
  <dt id="sigaction1"><a class="permalink" href="#sigaction1"><code class="Fn">sigaction1</code></a>(<var class="Fa">l</var>,
    <var class="Fa">signum</var>, <var class="Fa">nsa</var>,
    <var class="Fa">osa</var>, <var class="Fa">tramp</var>,
    <var class="Fa">vers</var>)</dt>
  <dd>
    <p class="Pp" id="sendsig">This function implements the
        <a class="Xr">sigaction(2)</a> system call. The
        <var class="Fa">tramp</var> and <var class="Fa">vers</var> arguments
        provide support for userspace signal trampolines. Trampoline version 0
        is reserved for the legacy kernel-provided signal trampoline;
        <var class="Fa">tramp</var> must be <code class="Dv">NULL</code> in this
        case. Otherwise, <var class="Fa">vers</var> specifies the ABI of the
        trampoline specified by <var class="Fa">tramp</var>. The signal
        trampoline ABI is machine-dependent, and must be coordinated with the
        <a class="permalink" href="#sendsig"><code class="Fn">sendsig</code></a>()
        function.</p>
  </dd>
  <dt id="sigprocmask1"><a class="permalink" href="#sigprocmask1"><code class="Fn">sigprocmask1</code></a>(<var class="Fa">l</var>,
    <var class="Fa">how</var>, <var class="Fa">nss</var>,
    <var class="Fa">oss</var>)</dt>
  <dd>
    <p class="Pp">This function implements the <a class="Xr">sigprocmask(2)</a>
        system call.</p>
  </dd>
  <dt id="sigpending1"><a class="permalink" href="#sigpending1"><code class="Fn">sigpending1</code></a>(<var class="Fa">l</var>,
    <var class="Fa">ss</var>)</dt>
  <dd>
    <p class="Pp">This function implements the <a class="Xr">sigpending(2)</a>
        system call.</p>
  </dd>
  <dt id="sigsuspend1"><a class="permalink" href="#sigsuspend1"><code class="Fn">sigsuspend1</code></a>(<var class="Fa">l</var>,
    <var class="Fa">ss</var>)</dt>
  <dd>
    <p class="Pp">This function implements the <a class="Xr">sigsuspend(2)</a>
        system call.</p>
  </dd>
  <dt id="sigaltstack1"><a class="permalink" href="#sigaltstack1"><code class="Fn">sigaltstack1</code></a>(<var class="Fa">l</var>,
    <var class="Fa">nss</var>, <var class="Fa">oss</var>)</dt>
  <dd>
    <p class="Pp">This function implements the <a class="Xr">sigaltstack(2)</a>
        system call.</p>
  </dd>
  <dt id="pgsignal"><a class="permalink" href="#pgsignal"><code class="Fn">pgsignal</code></a>(<var class="Fa">pgrp</var>,
    <var class="Fa">signum</var>, <var class="Fa">checkctty</var>)</dt>
  <dd>
    <p class="Pp" id="kpgsignal">This is a wrapper function for
        <a class="permalink" href="#kpgsignal"><code class="Fn">kpgsignal</code></a>()
        which is described below.</p>
  </dd>
  <dt><code class="Fn">kpgsignal</code>(<var class="Fa">pgrp</var>,
    <var class="Fa">ks</var>, <var class="Fa">data</var>,
    <var class="Fa">checkctty</var>)</dt>
  <dd>
    <p class="Pp" id="kpsignal">Schedule the signal
        <var class="Fa">ks-&gt;ksi_signo</var> to be delivered to all members of
        the process group <var class="Fa">pgrp</var>. If
        <var class="Fa">checkctty</var> is non-zero, the signal is only sent to
        processes which have a controlling terminal. The
        <var class="Fa">data</var> argument and the complete signal scheduling
        semantics are described in the
        <a class="permalink" href="#kpsignal"><code class="Fn">kpsignal</code></a>()
        function below.</p>
  </dd>
  <dt id="trapsignal"><a class="permalink" href="#trapsignal"><code class="Fn">trapsignal</code></a>(<var class="Fa">l</var>,
    <var class="Fa">ks</var>)</dt>
  <dd>
    <p class="Pp">Sends the signal <var class="Fa">ks-&gt;ksi_signo</var> caused
        by a hardware trap to the current process.</p>
  </dd>
  <dt id="psignal"><a class="permalink" href="#psignal"><code class="Fn">psignal</code></a>(<var class="Fa">p</var>,
    <var class="Fa">signum</var>)</dt>
  <dd>
    <p class="Pp" id="kpsignal~2">This is a wrapper function for
        <a class="permalink" href="#kpsignal~2"><code class="Fn">kpsignal</code></a>()
        which is described below.</p>
  </dd>
  <dt><code class="Fn">kpsignal</code>(<var class="Fa">p</var>,
    <var class="Fa">ks</var>, <var class="Fa">data</var>)</dt>
  <dd>
    <p class="Pp">Schedule the signal <var class="Fa">ks-&gt;ksi_signo</var> to
        be delivered to the process <var class="Fa">p</var>. The
        <var class="Fa">data</var> argument, if not
        <code class="Dv">NULL</code>, points to the file descriptor data that
        caused the signal to be generated in the <code class="Li">SIGIO</code>
        case.</p>
    <p class="Pp" id="issignal">With a few exceptions noted below, the target
        process signal disposition is updated and is marked as runnable, so
        further handling of the signal is done in the context of the target
        process after a context switch; see
        <a class="permalink" href="#issignal"><code class="Fn">issignal</code></a>()
        below. Note that <code class="Fn">kpsignal</code>() does not by itself
        cause a context switch to happen.</p>
    <p class="Pp">The target process is not marked as runnable in the following
        cases:</p>
    <ul class="Bl-bullet Bd-indent">
      <li>The target process is sleeping uninterruptibly. The signal will be
          noticed when the process returns from the system call or trap.</li>
      <li>The target process is currently ignoring the signal.</li>
      <li>If a stop signal is sent to a sleeping process that takes the default
          action (see <a class="Xr">sigaction(2)</a>), the process is stopped
          without awakening it.</li>
      <li>SIGCONT restarts a stopped process (or puts them back to sleep)
          regardless of the signal action (e.g., blocked or ignored).</li>
    </ul>
    <p class="Pp" id="kpsignal~3">If the target process is being traced,
        <a class="permalink" href="#kpsignal~3"><code class="Fn">kpsignal</code></a>()
        behaves as if the target process were taking the default action for
        <var class="Fa">signum</var>. This allows the tracing process to be
        notified of the signal.</p>
  </dd>
  <dt><code class="Fn">issignal</code>(<var class="Fa">l</var>)</dt>
  <dd>
    <p class="Pp">This function determines which signal, if any, is to be posted
        to the current process. A signal is to be posted if:</p>
    <ul class="Bl-bullet Bd-indent">
      <li>The signal has a handler provided by the program image.</li>
      <li>The signal should cause the process to dump core and/or
        terminate.</li>
      <li>The signal should interrupt the current system call.</li>
    </ul>
    <p class="Pp" id="issignal~2">Signals which cause the process to be stopped
        are handled within
        <a class="permalink" href="#issignal~2"><code class="Fn">issignal</code></a>()
        directly.</p>
    <p class="Pp" id="issignal~3"><a class="permalink" href="#issignal~3"><code class="Fn">issignal</code></a>()
        should be called by machine-dependent code when returning to userspace
        from a system call or other trap or interrupt by using the following
        code:</p>
    <div class="Bd Pp Bd-indent Li">
    <pre>while (signum = CURSIG(curproc))
	postsig(signum);</pre>
    </div>
  </dd>
  <dt id="postsig"><a class="permalink" href="#postsig"><code class="Fn">postsig</code></a>(<var class="Fa">signum</var>)</dt>
  <dd>
    <p class="Pp" id="postsig~2">The
        <a class="permalink" href="#postsig~2"><code class="Fn">postsig</code></a>()
        function is used to invoke the action for the signal
        <var class="Fa">signum</var> in the current process. If the default
        action of a signal is to terminate the process, and the signal does not
        have a registered handler, the process exits using
        <code class="Fn">sigexit</code>(), dumping a core image if
      necessary.</p>
  </dd>
  <dt id="killproc"><a class="permalink" href="#killproc"><code class="Fn">killproc</code></a>(<var class="Fa">p</var>,
    <var class="Fa">why</var>)</dt>
  <dd>
    <p class="Pp">This function sends a SIGKILL signal to the specified process.
        The message provided by <var class="Fa">why</var> is sent to the system
        log and is also displayed on the process's controlling terminal.</p>
  </dd>
  <dt id="sigexit"><a class="permalink" href="#sigexit"><code class="Fn">sigexit</code></a>(<var class="Fa">l</var>,
    <var class="Fa">signum</var>)</dt>
  <dd>
    <p class="Pp">This function forces the current process to exit with the
        signal <var class="Fa">signum</var>, generating a core file if
        appropriate. No checks are made for masked or caught signals; the
        process always exits.</p>
  </dd>
  <dt id="sendsig~2"><a class="permalink" href="#sendsig~2"><code class="Fn">sendsig</code></a>(<var class="Fa">ks</var>,
    <var class="Fa">mask</var>)</dt>
  <dd>
    <p class="Pp" id="sendsig~3">This function is provided by machine-dependent
        code, and is used to invoke a signal handler for the current process.
        <a class="permalink" href="#sendsig~3"><code class="Fn">sendsig</code></a>()
        must prepare the registers and stack of the current process to invoke
        the signal handler stored in the process's <var class="Fa">struct
        sigacts</var>. This may include switching to an alternate signal stack
        specified by the process. The previous register, stack, and signal state
        are stored in a <var class="Fa">ucontext_t</var>, which is then copied
        out to the user's stack.</p>
    <p class="Pp">The registers and stack must be set up to invoke the signal
        handler as follows:</p>
    <div class="Bd Pp Bd-indent Li">
    <pre>(*handler)(int signum, siginfo_t *info, void *ctx)</pre>
    </div>
    <p class="Pp">where <var class="Fa">signum</var> is the signal number,
        <var class="Fa">info</var> contains additional signal specific
        information when <code class="Li">SA_SIGINFO</code> is specified when
        setting up the signal handler. <var class="Fa">ctx</var> is the pointer
        to <var class="Fa">ucontext_t</var> on the user's stack. The registers
        and stack must also arrange for the signal handler to return to the
        signal trampoline. The trampoline is then used to return to the code
        which was executing when the signal was delivered using the
        <a class="Xr">setcontext(2)</a> system call.</p>
    <p class="Pp" id="sendsig~4">For performance reasons, it is recommended that
        <a class="permalink" href="#sendsig~4"><code class="Fn">sendsig</code></a>()
        arrange for the signal handler to be invoked directly on architectures
        where it is convenient to do so. In this case, the trampoline is used
        only for the signal return path. If it is not feasible to directly
        invoke the signal handler, the trampoline is also used to invoke the
        handler, performing any final set up that was not possible for
        <code class="Fn">sendsig</code>() to perform.</p>
    <p class="Pp" id="sendsig~5"><a class="permalink" href="#sendsig~5"><code class="Fn">sendsig</code></a>()
        must invoke the signal trampoline with the correct ABI. The ABI of the
        signal trampoline is specified on a per-signal basis in the
        <a class="permalink" href="#sigacts"><code class="Fn" id="sigacts">sigacts</code></a>()
        structure for the process. Trampoline version 0 is reserved for the
        legacy kernel-provided, on-stack signal trampoline. All other trampoline
        versions indicate a specific trampoline ABI. This ABI is coordinated
        with machine-dependent code in the system C library.</p>
  </dd>
</dl>
<section class="Ss">
<h2 class="Ss" id="SIGNAL_TRAMPOLINE"><a class="permalink" href="#SIGNAL_TRAMPOLINE">SIGNAL
  TRAMPOLINE</a></h2>
<p class="Pp">The signal trampoline is a special piece of code which provides
    support for invoking the signal handlers for a process. The trampoline is
    used to return from the signal handler back to the code which was executing
    when the signal was delivered, and is also used to invoke the handler itself
    on architectures where it is not feasible to have the kernel invoke the
    handler directly.</p>
<p class="Pp">In traditional <span class="Ux">UNIX</span> systems, the signal
    trampoline, also referred to as the &#x201C;sigcode&#x201D;, is provided by
    the kernel and copied to the top of the user's stack when a new process is
    created or a new program image is exec'd. Starting in
    <span class="Ux">NetBSD 2.0</span>, the signal trampoline is provided by the
    system C library. This allows for more flexibility when the signal facility
    is extended, makes dealing with signals easier in debuggers, such as
    <a class="Xr">gdb(1)</a>, and may also enhance system security by allowing
    the kernel to disallow execution of code on the stack.</p>
<p class="Pp">The signal trampoline is specified on a per-signal basis. The
    correct trampoline is selected automatically by the C library when a signal
    handler is registered by a process.</p>
<p class="Pp">Signal trampolines have a special naming convention which enables
    debuggers to determine the characteristics of the signal handler and its
    arguments. Trampoline functions are named like so:</p>
<div class="Bd Pp Bd-indent Li">
<pre>__sigtramp_&lt;flavor&gt;_&lt;version&gt;</pre>
</div>
<p class="Pp">where:</p>
<dl class="Bl-tag">
  <dt>&#x27E8;flavor&#x27E9;</dt>
  <dd>The flavor of the signal handler. The following flavors are valid:
    <dl class="Bl-tag">
      <dt>sigcontext</dt>
      <dd>Specifies a traditional BSD-style (deprecated) signal handler with the
          following signature:
        <div class="Bd Pp Li">
        <pre>void (*handler)(int signum,
	int code,
	struct sigcontext *scp);</pre>
        </div>
      </dd>
      <dt>siginfo</dt>
      <dd>Specifies a POSIX-style signal handler with the following signature:
        <div class="Bd Pp Li">
        <pre>void (*handler)(int signum,
	siginfo_t *si,
	void *uc);</pre>
        </div>
        <p class="Pp">Note: sigcontext style signal handlers are deprecated, and
            retained only for compatibility with older binaries.</p>
      </dd>
    </dl>
  </dd>
  <dt id="sendsig~6">&#x27E8;version&#x27E9;</dt>
  <dd>Specifies the ABI version of the signal trampoline. The trampoline ABI is
      coordinated with the machine-dependent kernel
      <a class="permalink" href="#sendsig~6"><code class="Fn">sendsig</code></a>()
      function. The trampoline version needs to be unique even across different
      trampoline flavors, in order to simplify trampoline selection in the
      kernel.</dd>
</dl>
<p class="Pp">The following is an example if a signal trampoline name which
    indicates that the trampoline is used for traditional BSD-style signal
    handlers and implements version 1 of the signal trampoline ABI:</p>
<div class="Bd Pp Bd-indent Li">
<pre>__sigtramp_sigcontext_1</pre>
</div>
<p class="Pp">The current signal trampoline is:</p>
<div class="Bd Pp Bd-indent Li">
<pre>__sigtramp_siginfo_2</pre>
</div>
</section>
</section>
<section class="Sh">
<h1 class="Sh" id="SEE_ALSO"><a class="permalink" href="#SEE_ALSO">SEE
  ALSO</a></h1>
<p class="Pp"><a class="Xr">sigaction(2)</a>, <a class="Xr">signal(7)</a>,
    <a class="Xr">condvar(9)</a></p>
</section>
</div>
<table class="foot">
  <tr>
    <td class="foot-date">April 29, 2010</td>
    <td class="foot-os">NetBSD 10.1</td>
  </tr>
</table>