In preparation for removing generated files, it is necessary
to tell automake that the generated files must be distributed
but not directly compiled (since they are included into the
body of a larger .c file that is compiled). Hence, even though
these files are code and not headers in the strict sense of
the word, it is easier to rename them to .h for automake's sake.
* daemon/remote_client_bodies.c: Rename to .h.
* daemon/qemu_client_bodies.c: Likewise.
* src/remote/remote_client_bodies.c: Likewise.
* src/remote/qemu_client_bodies.c: Likewise.
* daemon/Makefile.am (remote_dispatch_bodies.c)
(qemu_dispatch_bodies.c): Rename to .h.
(remote.c, EXTRA_DIST): Reflect rename.
* daemon/remote.c: Likewise.
* daemon/remote_generator.pl: Likewise.
* src/Makefile.am (remote/remote_driver.c): Likewise.
* src/remote/remote_driver.c: Likewise.
* po/POTFILES.in: Likewise.
* cfg.mk (exclude_file_name_regexp--sc_require_config_h)
(exclude_file_name_regexp--sc_require_config_h_first)
(exclude_file_name_regexp--sc_prohibit_empty_lines_at_EOF):
Likewise.
This patch just covers the simple functions without explicit return
values. There is more to be handled.
The generator collects the members of the XDR argument structs and uses
this information to generate the function bodies.
Exclude the generated files from offending syntax-checks.
Suggested by Richard W.M. Jones
Clang found three instances of uninitialized use of nparams in
the cleanup path. Unfortunately, one is a false positive: clang
couldn't see that ret->params.params_val is guaranteed to be
NULL unless allocated within a function, and that nparams is
guaranteed to be assigned prior to the allocation; hoisting the
assignment to nparams to be earlier in the function shuts up
that false positive. But two of the reports also happened to
highlight a real bug - the error path can dereference NULL.
Regression introduced in commit 158ba873.
* daemon/remote.c (remoteDispatchDomainGetMemoryParameters)
(remoteDispatchDomainGetBlkioParameters): Don't clear fields if
array was not allocated.
(remoteDispatchDomainGetSchedulerParameters): Initialize nparams
earlier.
Replace some occurrances of
virDomainPtr domain;
virNetworkPtr network;
With
virDomainPtr dom;
virNetworkPtr net;
* daemon/remote.c: Fix variable naming to follow standard
Replace cases of
type = virConnectGetType(conn);
if (type == NULL)
goto cleanup;
With
if (!(type = virConnectGetType(conn)))
goto cleanup;
* daemon/remote.c: Write error checks in compat form
Replace all occurrances of
if (....) {
goto cleanup;
}
With
if (.....)
goto cleanup;
to save one line of code
* daemon/remote.c: Remove curly braces on single line conditionals
The libvirt APIs reserve any negative value for indicating an
error. Thus checks
if (virXXXX() == -1)
Should instead be
if (virXXXX() < 0)
* daemon/remote.c: s/ == -1/ < 0/
The dispatcher functions have numerous places where they
return to the caller. This leads to duplicated cleanup
code, often resulting in memory leaks. It makes it harder
to ensure that errors are dispatched before freeing objects,
which may overwrite the original error.
The standard pattern is now
remoteDispatchXXX(...) {
int rv = -1;
....
if (XXX < 0)
goto cleanup;
...
if (XXXX < 0)
goto cleanup;
...
rv = 0;
cleanup:
if (rv < 0)
remoteDispatchError(rerr);
...free all other stuff..
return rv;
}
* daemon/remote.c: Centralize all cleanup paths
* daemon/stream.c: s/remoteDispatchConnError/remoteDispatchError/
* daemon/dispatch.c, daemon/dispatch.h: Replace
remoteDispatchConnError with remoteDispatchError
removing unused virConnectPtr
To install it, disable libvirtd sysv initscript:
chkconfig libvirtd off
service libvirtd stop
and enable libvirtd upstart job:
cp /usr/share/doc/libvirt-*/libvirtd.upstart \
/etc/init/libvirtd.conf
initctl reload-configuration
initctl start libvirtd
Test:
initctl status libvirtd
libvirtd start/running, process 3929
killall -9 libvirtd
initctl status libvirtd
libvirtd start/running, process 4047
I looked into the possibility to use the upstart script from Ubuntu or
at least getting inspiration from it but that's not possible. "expect
daemon" is a nice thing but it only works if the process is defined with
exec stanza instead of script ... no script. Unfortunately, with exec
stanza environment variables can only be set within upstart script
(i.e., configuration in /etc/sysconfig/libvirtd can't work). Hence, we
need to use script stanza, source sysconfig, and execute libvirtd
without --daemon. For similar reasons we can't use limit stanza and need
to handle DAEMON_COREFILE_LIMIT in job's script.
The daemon dispatcher code had an obsolete macro
#define REMOTE_DEBUG(fmt, ...) VIR_DEBUG(fmt, __VA_ARGS__)
This can be trivially removed
* daemon/remote.c: s/REMOTE_DEBUG/VIR_DEBUG/
Many functions did not check for whether a connection was
open. Replace the macro which obscures control flow, with
explicit checks, and ensure all dispatcher code has checks.
* daemon/remote.c: Add connection checks
A lot of code in libvirtd's dispatcher used the style
dom = get_nonnull_domain (conn, args->dom);
Instead of the normal libvirt style
dom = get_nonnull_domain(conn, args->dom);
* daemon/remote.c: Remove all whitelist before function brackets
The systemtap directory for tapsets is called
/usr/share/systemtap/tapset
Not
/usr/share/systemtap/tapsets
* daemon/Makefile.am,libvirt.spec.in: s/tapsets/tapset/
The daemon loops over the linked list of streams when a client
quits, closing any that the client hadn't already closed. Except
it didn't ever move to the next element in the list!
* daemon/stream.c: Fix loop over linked list of streams
The Open Nebula driver has been unmaintained since it was first
introduced. The only commits have been for tree-wide cleanups.
It also has a major design flaw, in that it only knows about guests
that it has created itself, which makes it of very limited use.
Discussions wrt evolution of the VMWare ESX driver, concluded that
it should limit itself to single-node ESX operation and not try to
manage the multi-node architecture of VirtualCenter. Open Nebula
is a cluster like Virtual Center, not a single node system, so
the same reasoning applies.
The DeltaCloud project includes an Open Nebula driver and is a much
better fit architecturally, since it is explicitly targetting the
distributed multihost cluster scenario.
Thus this patch deletes the libvirt Open Nebula driver with the
recommendation that people use DeltaCloud for managing it instead.
* configure.ac: Remove probe for xmlrpc & --with-one arg
* daemon/Makefile.am, daemon/libvirtd.c, src/Makefile.am: Remove
ONE driver build
* src/opennebula/one_client.c, src/opennebula/one_client.h,
src/opennebula/one_conf.c, src/opennebula/one_conf.h,
src/opennebula/one_driver.c, src/opennebula/one_driver.c: Delete
files
* autobuild.sh, libvirt.spec.in, mingw32-libvirt.spec.in: Remove
build rules for Open Nebula
* docs/drivers.html.in, docs/sitemap.html.in: Remove reference
to OpenNebula
* docs/drvone.html.in: Delete file
Commit f44bfb7 was supposed to make sure no additional libvirt API (esp.
*Free) is called before remoteDispatchConnError() is called on error.
However, the patch missed two instances.
Child processes don't always reach _exit(); if they die from a
signal, then any messages should still be accurate. Most users
either expect a 0 status (thankfully, if status==0, then
WIFEXITED(status) is true and WEXITSTATUS(status)==0 for all
known platforms) or were filtering on WIFEXITED before printing
a status, but a few were missing this check. Additionally,
nwfilter_ebiptables_driver was making an assumption that works
on Linux (where WEXITSTATUS shifts and WTERMSIG just masks)
but fails on other platforms (where WEXITSTATUS just masks and
WTERMSIG shifts).
* src/util/command.h (virCommandTranslateStatus): New helper.
* src/libvirt_private.syms (command.h): Export it.
* src/util/command.c (virCommandTranslateStatus): New function.
(virCommandWait): Use it to also diagnose status from signals.
* src/security/security_apparmor.c (load_profile): Likewise.
* src/storage/storage_backend.c
(virStorageBackendQEMUImgBackingFormat): Likewise.
* src/util/util.c (virExecDaemonize, virRunWithHook)
(virFileOperation, virDirCreate): Likewise.
* daemon/remote.c (remoteDispatchAuthPolkit): Likewise.
* src/nwfilter/nwfilter_ebiptables_driver.c (ebiptablesExecCLI):
Likewise.
Bug https://bugzilla.redhat.com/show_bug.cgi?id=689374 reported libvirtd
crash during error dispatch.
The reason is that libvirtd uses remoteDispatchConnError() with non-NULL
conn parameter which means that virConnGetLastError() is used instead of
its thread safe replacement virGetLastError().
So when several libvirtd threads are reporting errors at the same time,
the errors can get mixed or corrupted or in case of bad luck libvirtd
itself crashes.
Since Daniel B. is going to rewrite this code from scratch on top of his
RPC infrastructure, I tried to come up with a minimal fix. Thus,
remoteDispatchConnError() now just ignores its conn argument and always
calls virGetLastError(). However, several callers had to be touched as
well, since no libvirt API is allowed to be called before dispatching
the error. Doing so would reset the error and we would have nothing to
dispatch. As a result of that, the code is not very nice but that
doesn't really make daemon/remote.c worse than it is now :-) And it will
all die soon, which is good.
The bug report also contains a reproducer in C which detects both mixed
up error messages and libvirtd crash. Before this patch, I was able to
crash libvirtd in about 20 seconds up to 3 minutes depending on number
of CPU cores (more is better) and luck.
Add a new xen driver based on libxenlight [1], which is the primary
toolstack starting with Xen 4.1.0. The driver is stateful and runs
privileged only.
Like the existing xen-unified driver, the libxenlight driver is
accessed with xen:// URI. Driver selection is based on the status
of xend. If xend is running, the libxenlight driver will not load
and xen:// connections are handled by xen-unified. If xend is not
running *and* the libxenlight driver is available, xen://
connections are deferred to the libxenlight driver.
V6:
- Address several code style issues noted by Daniel Veillard
- Make drive work with xen:/// URI
- Hold domain object reference while domain is injected in
libvirt event loop. Race found and fixed by Markus Groß.
V5:
- Ensure events are unregistered when domain private data
is destroyed. Discovered and fixed by Markus Groß.
V4:
- Handle restart of libvirtd, reconnecting to previously
started domains
- Rebased to current master
- Tested against Xen 4.1 RC7-pre (c/s 22961:c5d121fd35c0)
V3:
- Reserve vnc port within driver when autoport=yes
V2:
- Update to Xen 4.1 RC6-pre (c/s 22940:5a4710640f81)
- Rebased to current master
- Plug memory leaks found by Stefano Stabellini and valgrind
- Handle SHUTDOWN_crash domain death event
[1] http://lists.xensource.com/archives/html/xen-devel/2009-11/msg00436.html
This is the part allowing to dynamically resize the debug log
buffer from it's default 64kB size. The buffer is now dynamically
allocated.
It adds a new API virLogSetBufferSize() which resizes the buffer
If passed a zero size, the buffer is deallocated and we do the small
optimization of not formatting messages which are not output anymore.
On the daemon side, it just adds a new option log_buffer_size to
libvirtd.conf and call virLogSetBufferSize() if needed
* src/util/logging.h src/util/logging.c src/libvirt_private.syms:
make buffer dynamic and add virLogSetBufferSize() internal API
* daemon/libvirtd.conf: document the new log_buffer_size option
* daemon/libvirtd.c: read and use the new log_buffer_size option
When building libvirt without libvirtd, I receive the following errors:
make[1]: Leaving directory `/home/wency/source/test/libvirt/src'
(cd daemon && make top_distdir=../libvirt-0.8.8 distdir=../libvirt-0.8.8/daemon \
am__remove_distdir=: am__skip_length_check=: am__skip_mode_fix=: distdir)
make[1]: Entering directory `/home/wency/source/test/libvirt/daemon'
make[1]: *** No rule to make target `libvirtd.8.in', needed by `distdir'. Stop.
This bug was caused by commit 6db98a2d.
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Not all applications have an existing event loop they need
to integrate with. Forcing them to implement the libvirt
event loop integration APIs is an undue burden. This just
exposes our simple poll() based implementation for apps
to use. So instead of calling
virEventRegister(....callbacks...)
The app would call
virEventRegisterDefaultImpl()
And then have a thread somewhere calling
static bool quit = false;
....
while (!quit)
virEventRunDefaultImpl()
* daemon/libvirtd.c, tools/console.c,
tools/virsh.c: Convert to public event loop APIs
* include/libvirt/libvirt.h.in, src/libvirt_private.syms: Add
virEventRegisterDefaultImpl and virEventRunDefaultImpl
* src/util/event.c: Implement virEventRegisterDefaultImpl
and virEventRunDefaultImpl using poll() event loop
* src/util/event_poll.c: Add full error reporting
* src/util/virterror.c, include/libvirt/virterror.h: Add
VIR_FROM_EVENTS
The event loop implementation is used by more than just the
daemon, so move it into the shared area.
* daemon/event.c, src/util/event_poll.c: Renamed
* daemon/event.h, src/util/event_poll.h: Renamed
* tools/Makefile.am, tools/console.c, tools/virsh.c: Update
to use new virEventPoll APIs
* daemon/mdns.c, daemon/mdns.c, daemon/Makefile.am: Update
to use new virEventPoll APIs
The daemon code calls virEventAddHandleImpl directly instead
of calling the wrapper virEventAddHandle.
* tools/console.c, daemon/libvirtd.c, daemon/mdns.c: Convert to
use primary event APIs
In case of imminent crash or upon request (signal USR2),
dump the logging buffer to the libvirtd.log file for
post-mortem analysis
* daemon/libvirtd.c: create a sig_fatal() handler connected to
SIGFPE SIGSEGV SIGILL SIGABRT SIGBUS and SIGUSR2, just dumping
the log buffer using virLogEmergencyDumpAll
As the file may grow quite a bit especially with debug turned on.
* daemon/libvirtd.logrotate.in daemon/Makefile.am libvirt.spec.in:
add new logrotate file for the daemon log
Syslog is not the best place to go search for libvirt error
logs, change it to a default file output libvirtd.log, but
still keep standard error if not run as a daemon.
Depending on whether it's run as root or user, the log is saved
in the local state dir or in $HOME/.libvirt.
* daemon/libvirtd.c: change default logging to go to libvirtd.log
Right now, 'man libvirtd' includes information that depends on
configure results, so it must be generated on the fly and live
in $(builddir); however, requiring pod2man on all end user
machines is overkill. Meanwhile, 'man virsh' doesn't mention
any configure results, so it can be built at 'make dist' time.
If that situation changes in the future, we can generate virsh.1
in the same way that we generate libvirtd.8.
* daemon/Makefile.am (libvirtd.8.in): New rule, to run pod2man in
advance of distribution.
(libvirtd.8): Use only sed from tarball.
(EXTRA_DIST): Ship new file.
(libvirtd.pod): Delete unused rule.
(man8_MANS): Let automake know which section to use.
(CLEANFILES, MAINTAINERCLEANFILES): Adjust to new files.
* tools/Makefile.am (dist_man1_MANS): Distribute pre-built man
pages, fine since they don't require any substitution.
(virt-xml-validate.1, virt-pki-validate.1): Change input source.
(virsh.1): Build into srcdir.
(CLEANFILES, MAINTAINERCLEANFILES): Adjust to new build style.
* daemon/.gitignore: Update.
Reported by Diego Elio Pettenò.
Done mechanically with:
$ git grep -l '\bDEBUG0\? *(' | xargs -L1 sed -i 's/\bDEBUG0\? *(/VIR_&/'
followed by manual deletion of qemudDebug in daemon/libvirtd.c, along
with a single 'make syntax-check' fallout in the same file, and the
actual deletion in src/util/logging.h.
* src/util/logging.h (DEBUG, DEBUG0): Delete.
* daemon/libvirtd.h (qemudDebug): Likewise.
* global: Change remaining clients over to VIR_DEBUG counterpart.
To make it easier to investigate problems with async event
delivery, add two more debugging lines
* daemon/remote.c: Debug when an event is queued for dispatch
* src/remote/remote_driver.c: Debug when an event is received
for processing
Fixes test failure that was overlooked after commit 1e1f7a8950.
* daemon/Makefile.am (check-local): Let 'make check' fail on error.
* daemon/test_libvirtd.aug: Move qemu-specific option...
* src/qemu/test_libvirtd_qemu.aug: ...into correct test.
* src/qemu/libvirtd_qemu.aug: Parse new option.
Regression introduced in commit e6b68d7 (Nov 2010).
Prior to that point, handlesAlloc was always a multiple of
EVENT_ALLOC_EXTENT (10), and was an int (so even if the subtraction
had been able to wrap, a negative value would be less than the count
not try to free the handles array). But after that point,
VIR_RESIZE_N made handlesAlloc grow geometrically (with a pattern of
10, 20, 30, 45 for the handles array) but still freed in multiples of
EVENT_ALLOC_EXTENT; and the count changed to size_t. Which means that
after 31 handles have been created, then 30 handles destroyed,
handlesAlloc is 5 while handlesCount is 1, and since (size_t)(1 - 5)
is indeed greater than 1, this then tried to free 10 elements, which
had the awful effect of nuking the handles array while there were
still live handles.
Nuking live handles puts libvirtd in an inconsistent state, and was
easily reproducible by starting and then stopping 60 faqemu guests.
* daemon/event.c (virEventCleanupTimeouts, virEventCleanupHandles):
Avoid integer wrap-around causing us to delete the entire array
while entries are still active.
* tests/eventtest.c (mymain): Expose the bug.
Add a hook to the error reporting APIs to allow specific
error messages to be filtered out. Wire up libvirtd to
remove VIR_ERR_NO_DOMAIN & similar error codes from the
logs. They are still logged at DEBUG level.
* daemon/libvirtd.c: Filter VIR_ERR_NO_DOMAIN and friends
* src/libvirt_private.syms, src/util/virterror.c,
src/util/virterror_internal.h: Hook for changing error
reporting level
This reverts the additions in commit
abff683f78
taking us back to state where all errors are fully logged
in both libvirtd and normal clients.
THe intent was to stop VIR_ERR_NO_DOMAIN (No such domain
with UUID XXXX) messages from client apps polluting syslog
The change affected all error codes, but more seriously,
it also impacted errors from internal libvirtd infrastructure
For example guest autostart no longer logged errors. The
libvirtd network code no longer logged some errors. This
makes debugging incredibly hard
* daemon/libvirtd.c: Remove error log priority filter
* src/util/virterror.c, src/util/virterror_internal.h: Remove
callback for overriding log priority
This bug has been present since before the time that commit
f8a519 (Dec 2008) tried to make the dispatch loop re-entrant.
Dereferencing eventLoop.handles outside the lock risks crashing, since
any other thread could have reallocated the array in the meantime.
It's a narrow race window, however, and one that would have most
likely resulted in passing bogus data to the callback rather than
actually causing a segv, which is probably why it has gone undetected
this long.
* daemon/event.c (virEventDispatchHandles): Cache data while
inside the lock, as the array might be reallocated once outside.
Setting unix_sock_group to something else than default "root" in
/etc/libvirt/libvirtd.conf prevents system libvirtd from dumping core on
crash. This is because we used setgid(unix_sock_group) before binding to
/var/run/libvirt/libvirt-sock* and setgid() back to original group.
However, if a process changes its effective or filesystem group ID, it
will be forbidden from leaving core dumps unless fs.suid_dumpable sysctl
is set to something else then 0 (and it is 0 by default).
Changing socket's group ownership after bind works better. And we can do
so without introducing a race condition since we loosen access rights by
changing the group from root to something else.
* .gnulib: Update to latest.
* bootstrap.conf (gnulib_modules): Import pipe-posix and waitpid
for mingw.
* src/remote/remote_driver.c (pipe) [WIN32]: Drop dead macro.
* daemon/event.c (pipe) [WIN32]: Drop dead function.
* src/util/threads.h (virThreadID): New prototype.
* src/util/threads-pthread.c (virThreadID): New function.
* src/util/threads-win32.c (virThreadID): Likewise.
* src/libvirt_private.syms (threads.h): Export it.
* daemon/event.c (virEventInterruptLocked): Use it to avoid
warning on BSD systems.
This reverts commit
Log all errors at level INFO to stop polluting syslog
04bd0360f3.
and makes virRaiseErrorFull() log errors at debug priority
when called from inside libvirtd. This stops libvirtd from
polluting it's own log with client errors at error priority
that'll be reported and logged on the client side anyway.
libvirtd no longer deals with SIGCHLD in its signal handler
since the QEMU driver switched to always daemonize processes.
Thus remove the sigaction for it, to avoid warning log
messages
* daemon/libvirtd.c: Don't catch SIGCHLD
The virt-mem program is no longer shipped, but was still being
referenced at the bottom of the virsh and libvirtd man pages.
This patch removes it from those man pages, addressing
BZ# 639603:
https://bugzilla.redhat.com/show_bug.cgi?id=639603
* daemon/libvirtd.h (qemud_server): Change types of members
tracking array sizes, and add allocation trackers.
* daemon/event.c (virEventLoop): Likewise.
(virEventAddHandleImpl, virEventAddTimeoutImpl)
(virEventCleanupTimeouts, virEventCleanupHandles): Use
VIR_RESIZE_N instead of VIR_REALLOC_N. Tweak debug messages to
match type changes.
* daemon/libvirtd.c (qemudDispatchServer, qemudRunLoop): Likewise.
Per the gettext developer:
http://lists.gnu.org/archive/html/bug-gnu-utils/2010-10/msg00019.htmlhttp://lists.gnu.org/archive/html/bug-gnu-utils/2010-10/msg00021.html
gettext() doesn't work correctly on all platforms unless you have
called setlocale(). Furthermore, gnulib's gettext.h has provisions
for setting up a default locale, which is the preferred method for
libraries to use gettext without having to call textdomain() and
override the main program's default domain (virInitialize already
calls bindtextdomain(), but this is insufficient without the
setlocale() added in this patch; and a redundant bindtextdomain()
in this patch doesn't hurt, but serves as a good example for other
packages that need to bind a second translation domain).
This patch is needed to silence a new gnulib 'make syntax-check'
rule in the next patch.
* daemon/libvirtd.c (main): Setup locale and gettext.
* src/lxc/lxc_controller.c (main): Likewise.
* src/security/virt-aa-helper.c (main): Likewise.
* src/storage/parthelper.c (main): Likewise.
* tools/virsh.c (main): Fix exit status.
* src/internal.h (DEFAULT_TEXT_DOMAIN): Define, for gettext.h.
(_): Simplify definition accordingly.
* po/POTFILES.in: Add src/storage/parthelper.c.
Similarly to deprecating close(), I am now deprecating fclose() and
introduce VIR_FORCE_FCLOSE() and VIR_FCLOSE(). Also, fdopen() is replaced with
VIR_FDOPEN().
Most of the files are opened in read-only mode, so usage of
VIR_FORCE_CLOSE() seemed appropriate. Others that are opened in write
mode already had the fclose()< 0 check and I converted those to
VIR_FCLOSE()< 0.
I did not find occurrences of possible double-closed files on the way.
When closing open streams after a client quits, the event
callback was not removed. This mean that poll() was using
a closed FD and returning POLLNVAL in a busy-wait loop.
* daemon/stream.c: Disconnect stream callbacks
The code currently uses pthreads APIs directly. This is not
portable to Win32 threads. Switch it over to use the portability
APIs. Also add a wrapper for pipe() which is subtely different
on Win32
* daemon/event.c: Switch to use virMutex & virThread.
This provides an implementation of the virDomainOpenConsole
API for the remote driver client and server.
* daemon/remote.c: Server side impl
* src/remote/remote_driver.c: Client impl
* src/remote/remote_protocol.x: Wire definition
Using automated replacement with sed and editing I have now replaced all
occurrences of close() with VIR_(FORCE_)CLOSE() except for one, of
course. Some replacements were straight forward, others I needed to pay
attention. I hope I payed attention in all the right places... Please
have a look. This should have at least solved one more double-close
error.
Commit e8066d53 broke the build with polkit0:
remote.c: In function 'remoteDispatchAuthPolkit':
remote.c:4177: error: 'rv' undeclared (first use in this function)
Add missing identifier.
Revert most of commit a8b5f9bd27.
The audit hooks will be re-added directly in the QEMU driver code
in a future commit
* daemon/remote.c: Remove all audit logging hooks
* src/qemu/qemu_driver.c: Remove all audit logging hooks
With SystemTap 1.0 a part of the generated macros in probes.h
expands to:
volatile __typeof__(((name))) arg2 = (name);
GCC reports an 'invalid initialize' error when name has type
char[]. Therfore, add casts to char* to avoid this.
This 1-liner was actually written by Eric Blake, over IRC. It
addresses a compilation failure in make dist and make rpm for
systems without the dtrace/systemtap development libraries
installed.
