From time to time weird bugreports occur on the list, e.g [1].
Even though the kernel supports setns syscall, there's an older
glibc in the system that misses a wrapper over the syscall.
Hence, after the configure phase we think there's no setns
support in the system, which is obviously wrong. On the other
hand, we can't rely on linux distributions to provide newer glibc
soon. Therefore we need to introduce the wrapper on or own.
1: https://www.redhat.com/archives/libvir-list/2014-September/msg00492.html
Signed-off-by: Stephan Sachse <ste.sachse@gmail.com>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
virProcessTranslateStatus is used on error paths that should not spoil
the returned error. As the errors are ignored, use the quiet versions of
virAsprintf to create the message.
This fixes compilation on kFreeBSD which otherwise fails like
CC util/libvirt_util_la-virprocess.lo
In file included from /usr/include/sys/cpuset.h:35:0,
from util/virprocess.c:43:
/usr/include/sys/_cpuset.h:49:43: error: 'NBBY' undeclared here (not in
a function)
long __bits[howmany(CPU_SETSIZE, _NCPUBITS)];
^
In file included from util/virprocess.c:43:0:
/usr/include/sys/cpuset.h:215:12: error: unknown type name 'cpusetid_t'
int cpuset(cpusetid_t *);
^
/usr/include/sys/cpuset.h:216:30: error: expected ')' before 'id_t'
int cpuset_setid(cpuwhich_t, id_t, cpusetid_t);
^
/usr/include/sys/cpuset.h:217:42: error: expected ')' before 'id_t'
int cpuset_getid(cpulevel_t, cpuwhich_t, id_t, cpusetid_t *);
^
/usr/include/sys/cpuset.h:218:48: error: expected ')' before 'id_t'
int cpuset_getaffinity(cpulevel_t, cpuwhich_t, id_t, size_t, cpuset_t
*);
^
/usr/include/sys/cpuset.h:219:48: error: expected ')' before 'id_t'
int cpuset_setaffinity(cpulevel_t, cpuwhich_t, id_t, size_t, const
cpuset_t *);
And it's the correct usage as documented in
http://www.freebsd.org/cgi/man.cgi?query=cpuset_setid
Also change the #ifdef HAVE_BSH_CPU_AFFINITY to #if for consistency.
Any source file which calls the logging APIs now needs
to have a VIR_LOG_INIT("source.name") declaration at
the start of the file. This provides a static variable
of the virLogSource type.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The old semantics of virFork() violates the priciple of good
usability: it requires the caller to check the pid argument
after use, *even when virFork returned -1*, in order to properly
abort a child process that failed setup done immediately after
fork() - that is, the caller must call _exit() in the child.
While uses in virfile.c did this correctly, uses in 'virsh
lxc-enter-namespace' and 'virt-login-shell' would happily return
from the calling function in both the child and the parent,
leading to very confusing results. [Thankfully, I found the
problem by inspection, and can't actually trigger the double
return on error without an LD_PRELOAD library.]
It is much better if the semantics of virFork are impossible
to abuse. Looking at virFork(), the parent could only ever
return -1 with a non-negative pid if it misused pthread_sigmask,
but this never happens. Up until this patch series, the child
could return -1 with non-negative pid if it fails to set up
signals correctly, but we recently fixed that to make the child
call _exit() at that point instead of forcing the caller to do
it. Thus, the return value and contents of the pid argument are
now redundant (a -1 return now happens only for failure to fork,
a child 0 return only happens for a successful 0 pid, and a
parent 0 return only happens for a successful non-zero pid),
so we might as well return the pid directly rather than an
integer of whether it succeeded or failed; this is also good
from the interface design perspective as users are already
familiar with fork() semantics.
One last change in this patch: before returning the pid directly,
I found cases where using virProcessWait unconditionally on a
cleanup path of a virFork's -1 pid return would be nicer if there
were a way to avoid it overwriting an earlier message. While
such paths are a bit harder to come by with my change to a direct
pid return, I decided to keep the virProcessWait change in this
patch.
* src/util/vircommand.h (virFork): Change signature.
* src/util/vircommand.c (virFork): Guarantee that child will only
return on success, to simplify callers. Return pid rather than
status, now that the situations are always the same.
(virExec): Adjust caller, also avoid open-coding process death.
* src/util/virprocess.c (virProcessWait): Tweak semantics when pid
is -1.
(virProcessRunInMountNamespace): Adjust caller.
* src/util/virfile.c (virFileAccessibleAs, virFileOpenForked)
(virDirCreate): Likewise.
* tools/virt-login-shell.c (main): Likewise.
* tools/virsh-domain.c (cmdLxcEnterNamespace): Likewise.
* tests/commandtest.c (test23): Likewise.
Signed-off-by: Eric Blake <eblake@redhat.com>
Right now, a caller waiting for a child process either requires
the child to have status 0, or must use WIFEXITED() and friends
itself. But in many cases, we want the middle ground of treating
fatal signals as an error, and directly accessing the normal exit
value without having to use WEXITSTATUS(), in order to easily
detect an expected non-zero exit status. This adds the middle
ground to the low-level virProcessWait; the next patch will add
it to virCommand.
* src/util/virprocess.h (virProcessWait): Alter signature.
* src/util/virprocess.c (virProcessWait): Add parameter.
(virProcessRunInMountNamespace): Adjust caller.
* src/util/vircommand.c (virCommandWait): Likewise.
* src/util/virfile.c (virFileAccessibleAs): Likewise.
* src/lxc/lxc_container.c (lxcContainerHasReboot)
(lxcContainerAvailable): Likewise.
* daemon/libvirtd.c (daemonForkIntoBackground): Likewise.
* tools/virt-login-shell.c (main): Likewise.
* tools/virsh-domain.c (cmdLxcEnterNamespace): Likewise.
* tests/testutils.c (virtTestCaptureProgramOutput): Likewise.
* tests/commandtest.c (test23): Likewise.
Signed-off-by: Eric Blake <eblake@redhat.com>
The documentation of namespace callbacks was inconsistent on whether
it preserved positive return values. Now that we have a dedicated
EXIT_CANCELED to flag all errors before getting to the callback,
it is possible to use positive return values (not that any of the
current callers do, but it is better to match the docs).
Also, while vircommand.c is careful to close fds that a child should
not have, it's still better to be in the practice of setting
FD_CLOEXEC up front.
* src/util/virprocess.c (virProcessRunInMountNamespace): Tweak
return value to pass back non-zero status. Avoid leaking pipe fds
to other threads.
* src/util/virprocess.h: Fix comment.
Signed-off-by: Eric Blake <eblake@redhat.com>
Thanks to namespaces, we have a couple of places in the code
base that want to reflect a child exit status, including the
ability to detect death by a signal, back to a grandparent.
Best to make it a reusable function.
* src/util/virprocess.h (virProcessExitWithStatus): New prototype.
* src/libvirt_private.syms (util/virprocess.h): Export it.
* src/util/virprocess.c (virProcessExitWithStatus): New function.
* tests/commandtest.c (test23): Test it.
Signed-off-by: Eric Blake <eblake@redhat.com>
Implement virProcessRunInMountNamespace, which runs callback of type
virProcessNamespaceCallback in a container namespace. This uses a
child process to run the callback, since you can't change the mount
namespace of a thread. This implies that callbacks have to be careful
about what code they run due to async safety rules.
Idea by Dan Berrange, based on an initial report by Reco
<recoverym4n@gmail.com> at
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=732394
Signed-off-by: Daniel Berrange <berrange@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Implement virProcess{Get,Set}Affinity() using cpuset_getaffinity()
and cpuset_setaffinity() calls. Quick search showed that they are
only available on FreeBSD, so placed it inside existing #ifdef
blocks for FreeBSD instead of adding configure checks.
Convert the type of loop iterators named 'i', 'j', k',
'ii', 'jj', 'kk', to be 'size_t' instead of 'int' or
'unsigned int', also santizing 'ii', 'jj', 'kk' to use
the normal 'i', 'j', 'k' naming
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
virProcessGetNamespaces() opens files in /proc/XXX/ns/ which will
later be passed to setns(). We have to make sure that the file
descriptors in the array are in the correct order. In particular
the 'user' namespace must be first otherwise setns() may fail
for other namespaces.
The order has been taken from util-linux's sys-utils/nsenter.c
Also we must ignore EINVAL in setns() which occurs if the
namespace associated with the fd, matches the calling process'
current namespace.
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Resolves:https://bugzilla.redhat.com/show_bug.cgi?id=927620
#kill -STOP `pidof qemu-kvm`
#virsh destroy $guest --graceful
error: Failed to destroy domain testVM
error: An error occurred, but the cause is unknown
With --graceful, SIGTERM always is emitted to kill driver
process, but it won't success till burning out waiting time
in case of process being stopped.
But domain destroy without --graceful can work, SIGKILL will
be emitted to the stopped process after 10 secs which always
kills a process even one that is currently stopped.
So report an error after burning out waiting time in this case.
Since PIDs can be reused, polkit prefers to be given
a (PID,start time) pair. If given a PID on its own,
it will attempt to lookup the start time in /proc/pid/stat,
though this is subject to races.
It is safer if the client app resolves the PID start
time itself, because as long as the app has the client
socket open, the client PID won't be reused.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Commit 776d49f4 added a static function that is only called
conditionally; leading to this compile error on mingw:
CC libvirt_util_la-virprocess.lo
../../src/util/virprocess.c:624:26: error: 'struct rlimit' declared inside parameter list [-Werror]
../../src/util/virprocess.c:624:26: error: its scope is only this definition or declaration, which is probably not what you want [-Werror]
../../src/util/virprocess.c:622:1: error: 'virProcessPrLimit' defined but not used [-Werror=unused-function]
* src/util/virprocess.c (virProcessPrLimit): Only declare
virProcessPrLimit when used.
Signed-off-by: Eric Blake <eblake@redhat.com>
The source code base needs to be adapted as well. Some files
include virutil.h just for the string related functions (here,
the include is substituted to match the new file), some include
virutil.h without any need (here, the include is removed), and
some require both.
This patch adds two sets of functions:
1) lower level virProcessSet*() functions that will immediately set
the RLIMIT_MEMLOCK. RLIMIT_NPROC, or RLIMIT_NOFILE of either the
current process (using setrlimit()) or any other process (using
prlimit()). "current process" is indicated by passing a 0 for pid.
2) functions for virCommand* that will setup a virCommand object to
set those limits at a later time just after it has forked a new
process, but before it execs the new program.
configure.ac has prlimit and setrlimit added to the list of functions
to check for, and the low level functions log an "unsupported" error)
on platforms that don't support those functions.
virPidFileReadPathIfAlive passed in an 'int *' where a 'pid_t *'
was expected, which breaks on Mingw64 targets. Also a few places
were using '%d' for formatting pid_t, change them to '%lld' and
force a cast to the longer type as done elsewhere in the same
file.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Win32 platforms don't have SIGKILL defined, but they do have
SIGABRT. Since our virProcess wrapper treats anything which
isn't SIGTERM/SIGINT as equivalent to SIGKILL, just use
SIGABRT on Win32.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
In the cgroups APIs we have a virCgroupKillPainfully function
which does the loop sending SIGTERM, then SIGKILL and waiting
for the process to exit. There is similar functionality for
simple processes in qemuProcessKill, but it is tangled with
the QEMU code. Untangle it to provide a virProcessKillPainfuly
function
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Continue consolidation of process functions by moving some
helpers out of command.{c,h} into virprocess.{c,h}
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
There are a number of process related functions spread
across multiple files. Start to consolidate them by
creating a virprocess.{c,h} file
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
