net: Fix memory leaks in lltable_calc_llheader() error paths

[markj]

Summary

Also convert raw epoch_call() calls to lltable_free_entry() calls, no
functional change intended. There's no need to asynchronously free the
LLEs in that case to begin with, but we might as well use the lltable
interfaces consistently.

Noticed by code inspection, I think lltable_calc_llheader() failures do
not generally happen in practice.

sys/net/if_llatbl.c

 .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
 .\" $FreeBSD$
 .\"
-.Dd March 8, 2015
+.Dd April 18, 2015
 .Dt SDT 9
 .Os
 .Sh NAME
 .Nm SDT
 .Nd a DTrace framework for adding statically-defined tracing probes
 .Sh SYNOPSIS
 .In sys/param.h
 .In sys/queue.h

 .Pp
 The
 .Fn SDT_PROBE*
 macros are used to create
 .Nm
 trace points.
 They are meant to be added to executable code and can be used to instrument the
 code in which they are called.
+.Sh PROVIDERS
+A number of kernel DTrace providers are available.
+In general, these providers define stable interfaces and should be treated as
+such: existing D scripts may be broken if a probe is renamed or its arguments
+are modified.
+However, it is often useful to define ad-hoc
+.Nm
+probes for debugging a subsystem or driver.
+Similarly, a developer may wish to provide a group of
+.Nm
+probes without committing to their future stability.
+Such probes should be added to the
+.Ql sdt
+provider instead of defining a new provider.
 .Sh EXAMPLES
+The DTrace providers available on the current system can be listed with
+.Bd -literal -offset indent
+dtrace -l | sed 1d | awk '{print $2}' | sort -u
+.Ed
+.Pp
+A detailed list of the probes offered by a given provider can be obtained by
+specifying the provider using the
+.Fl P
+flag.
+For example, to view the probes and argument types for the
+.Ql sched
+provider, run
+.Bd -literal -offset indent
+dtrace -lv -P sched
+.Ed
+.Pp
 The following probe definition will create a DTrace probe called
 .Ql icmp:::receive-unreachable ,
 which would hypothetically be triggered when the kernel receives an ICMP packet
 of type Destination Unreachable:
 .Bd -literal -offset indent
 SDT_PROVIDER_DECLARE(icmp);
 
 SDT_PROBE_DEFINE1(icmp, , , receive__unreachable,

sys/netinet/in.c

 .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
 .\" $FreeBSD$
 .\"
-.Dd March 8, 2015
+.Dd April 18, 2015
 .Dt SDT 9
 .Os
 .Sh NAME
 .Nm SDT
 .Nd a DTrace framework for adding statically-defined tracing probes
 .Sh SYNOPSIS
 .In sys/param.h
 .In sys/queue.h

 .Pp
 The
 .Fn SDT_PROBE*
 macros are used to create
 .Nm
 trace points.
 They are meant to be added to executable code and can be used to instrument the
 code in which they are called.
+.Sh PROVIDERS
+A number of kernel DTrace providers are available.
+In general, these providers define stable interfaces and should be treated as
+such: existing D scripts may be broken if a probe is renamed or its arguments
+are modified.
+However, it is often useful to define ad-hoc
+.Nm
+probes for debugging a subsystem or driver.
+Similarly, a developer may wish to provide a group of
+.Nm
+probes without committing to their future stability.
+Such probes should be added to the
+.Ql sdt
+provider instead of defining a new provider.
 .Sh EXAMPLES
+The DTrace providers available on the current system can be listed with
+.Bd -literal -offset indent
+dtrace -l | sed 1d | awk '{print $2}' | sort -u
+.Ed
+.Pp
+A detailed list of the probes offered by a given provider can be obtained by
+specifying the provider using the
+.Fl P
+flag.
+For example, to view the probes and argument types for the
+.Ql sched
+provider, run
+.Bd -literal -offset indent
+dtrace -lv -P sched
+.Ed
+.Pp
 The following probe definition will create a DTrace probe called
 .Ql icmp:::receive-unreachable ,
 which would hypothetically be triggered when the kernel receives an ICMP packet
 of type Destination Unreachable:
 .Bd -literal -offset indent
 SDT_PROVIDER_DECLARE(icmp);
 
 SDT_PROBE_DEFINE1(icmp, , , receive__unreachable,

sys/netinet6/in6.c

 .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
 .\" $FreeBSD$
 .\"
-.Dd March 8, 2015
+.Dd April 18, 2015
 .Dt SDT 9
 .Os
 .Sh NAME
 .Nm SDT
 .Nd a DTrace framework for adding statically-defined tracing probes
 .Sh SYNOPSIS
 .In sys/param.h
 .In sys/queue.h

 .Pp
 The
 .Fn SDT_PROBE*
 macros are used to create
 .Nm
 trace points.
 They are meant to be added to executable code and can be used to instrument the
 code in which they are called.
+.Sh PROVIDERS
+A number of kernel DTrace providers are available.
+In general, these providers define stable interfaces and should be treated as
+such: existing D scripts may be broken if a probe is renamed or its arguments
+are modified.
+However, it is often useful to define ad-hoc
+.Nm
+probes for debugging a subsystem or driver.
+Similarly, a developer may wish to provide a group of
+.Nm
+probes without committing to their future stability.
+Such probes should be added to the
+.Ql sdt
+provider instead of defining a new provider.
 .Sh EXAMPLES
+The DTrace providers available on the current system can be listed with
+.Bd -literal -offset indent
+dtrace -l | sed 1d | awk '{print $2}' | sort -u
+.Ed
+.Pp
+A detailed list of the probes offered by a given provider can be obtained by
+specifying the provider using the
+.Fl P
+flag.
+For example, to view the probes and argument types for the
+.Ql sched
+provider, run
+.Bd -literal -offset indent
+dtrace -lv -P sched
+.Ed
+.Pp
 The following probe definition will create a DTrace probe called
 .Ql icmp:::receive-unreachable ,
 which would hypothetically be triggered when the kernel receives an ICMP packet
 of type Destination Unreachable:
 .Bd -literal -offset indent
 SDT_PROVIDER_DECLARE(icmp);
 
 SDT_PROBE_DEFINE1(icmp, , , receive__unreachable,

sys/netinet6/nd6.c

 .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
 .\" $FreeBSD$
 .\"
-.Dd March 8, 2015
+.Dd April 18, 2015
 .Dt SDT 9
 .Os
 .Sh NAME
 .Nm SDT
 .Nd a DTrace framework for adding statically-defined tracing probes
 .Sh SYNOPSIS
 .In sys/param.h
 .In sys/queue.h

 .Pp
 The
 .Fn SDT_PROBE*
 macros are used to create
 .Nm
 trace points.
 They are meant to be added to executable code and can be used to instrument the
 code in which they are called.
+.Sh PROVIDERS
+A number of kernel DTrace providers are available.
+In general, these providers define stable interfaces and should be treated as
+such: existing D scripts may be broken if a probe is renamed or its arguments
+are modified.
+However, it is often useful to define ad-hoc
+.Nm
+probes for debugging a subsystem or driver.
+Similarly, a developer may wish to provide a group of
+.Nm
+probes without committing to their future stability.
+Such probes should be added to the
+.Ql sdt
+provider instead of defining a new provider.
 .Sh EXAMPLES
+The DTrace providers available on the current system can be listed with
+.Bd -literal -offset indent
+dtrace -l | sed 1d | awk '{print $2}' | sort -u
+.Ed
+.Pp
+A detailed list of the probes offered by a given provider can be obtained by
+specifying the provider using the
+.Fl P
+flag.
+For example, to view the probes and argument types for the
+.Ql sched
+provider, run
+.Bd -literal -offset indent
+dtrace -lv -P sched
+.Ed
+.Pp
 The following probe definition will create a DTrace probe called
 .Ql icmp:::receive-unreachable ,
 which would hypothetically be triggered when the kernel receives an ICMP packet
 of type Destination Unreachable:
 .Bd -literal -offset indent
 SDT_PROVIDER_DECLARE(icmp);
 
 SDT_PROBE_DEFINE1(icmp, , , receive__unreachable,