This function can be used to retrieve the current locked memory
limit for a process, so that the setting can be later restored.

Add a configure check for getrlimit(), which we now use.

The prlimit() function allows both getting and setting limits for
a process; expose the same functionality in our wrapper.

Add the const modifier for new_limit, in accordance with the
prototype for prlimit().

This can be useful for debugging.

VIR_DEBUG and VIR_WARN will automatically add a new line to the message,
having "\n" at the end or at the beginning of the message results in
empty lines.
Signed-off-by: NJiri Denemark <jdenemar@redhat.com>

Use the virProcessGetStartTime implementation also when only the kernel
is FreeBSD, such as on GNU/kFreeBSD.

So far, the virProcessSetNamespaces() takes an array of FDs that
it tries to set namespace on. However, in the very next commit
this array may be sparse, having some -1's in it. Teach the
function to cope with that.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

Ever since commit e44b0269, 64-bit mingw compilation fails with:

../../src/util/virprocess.c: In function 'virProcessGetPids':
../../src/util/virprocess.c:628:50: error: passing argument 4 of 'virStrToLong_i' from incompatible pointer type [-Werror=incompatible-pointer-types]
         if (virStrToLong_i(ent->d_name, NULL, 10, &tmp_pid) < 0)
                                                  ^
In file included from ../../src/util/virprocess.c:59:0:
../../src/util/virstring.h:53:5: note: expected 'int *' but argument is of type 'pid_t * {aka long long int *}'
 int virStrToLong_i(char const *s,
     ^
cc1: all warnings being treated as errors

Although mingw won't be using this function, it does compile the
file, and the fix is relatively simple.

* src/util/virprocess.c (virProcessGetPids): Don't assume pid_t
fits in int.
Signed-off-by: NEric Blake <eblake@redhat.com>

Commit id 'e44b0269' in advertently checked !dir before calling closedir

This function gets all the PIDs listed in /proc/PID/task. This will be
needed at least to move all qmeu-nbd tasks to the container cgroup.

Store the cpu count in an intermediate variable and reuse it rather than
caluclating the index.

Additionally add a coverity silencing comment.

Commit 825df8c3 refactored virProcess{Set,Get}Affinity routines,
however broke BSD implementation because of the incorrect variable
name. Fix build by using a proper variable name.

Pushing as trivial and build break fix.

Refactor the function to return the bitmap instead of an integer and the
inner workings so that they make more sense.

This patch also fixes possible segfault on old systems that was
introduced by commit:

commit f1a43a8e
Author: Hu Tao <hutao@cn.fujitsu.com>
Date:   Fri Sep 14 15:46:59 2012 +0800

    use virBitmap to store cpu affinity info

lxc-enter-namespace stopped working on recent kernels (at least 3.19+)
due to /proc/PID/ns/* file descriptors being opened RW. From outside
the namespace these can only be opened RO.

Wikipedia's list of common misspellings [1] has a machine-readable
version.  This patch fixes those misspellings mentioned in the list
which don't have multiple right variants (as e.g. "accension", which can
be both "accession" and "ascension"), such misspellings are left
untouched.  The list of changes was manually re-checked for false
positives.

[1] https://en.wikipedia.org/wiki/Wikipedia:Lists_of_common_misspellings/For_machinesSigned-off-by: NMartin Kletzander <mkletzan@redhat.com>

A helper that never returns an error and treats bits out of bitmap range
as false.

Use it everywhere we use ignore_value on virBitmapGetBit, or loop over
the bitmap size.

Commit b6a2828e introduced new functions to set process scheduler. There
is a small typo in ELSE path for systems where scheduler is not
available.

Also some of the definitions were introduced later in kernel. For
example RHEL-5 is running on kernel 2.6.18, but SCHED_IDLE was introduces
in 2.6.23 [1] and SCHED_BATCH in 2.6.16 [1]. We should not count only on
existence of function sched_setscheduler(), we must also check for
existence of used macros as they might not be defined.

[1] see 'man 7 sched'
Signed-off-by: NPavel Hrdina <phrdina@redhat.com>

This function uses sched_setscheduler() function so it works with
processes and threads as well (even threads not created by us, which is
what we'll need in the future).
Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

The code assumes that def->vcpus == nvcpupids, so when we setup
fake CPU pids for old QEMU with nvcpupids == 1, we cause the
later code to read off the end of the array. This has fun results
like sche_setaffinity(0, ...) which changes libvirtd's own CPU
affinity, or even better sched_setaffinity($RANDOM, ...) which
changes the affinity of a random OS process.

C guarantees that static variables are zero-initialized.  Some older
compilers (and also gcc -fno-zero-initialized-in-bss) create larger
binaries if you explicitly zero-initialize a static variable.

* src/libvirt.c: Fix initialization.
* src/util/viralloc.c: Likewise.
* src/util/virdbus.c: Likewise.
* src/util/virevent.c: Likewise.
* src/util/virfile.c (safezero): Likewise.
* src/util/virlog.c: Likewise.
* src/util/virnetlink.c: Likewise.
* src/util/virthread.h (VIR_ONCE_GLOBAL_INIT): Likewise.
* src/util/virprocess.c (virProcessGetStartTime): Likewise.
Signed-off-by: NEric Blake <eblake@redhat.com>

The actual origin of this so called typo are two commits.  The first one
was commit 72f8a7f1 that came up with the following condition:

if ((i == 8) & (flags & VIR_QEMU_PROCESS_KILL_FORCE))

Fortunately this succeeded thanks to bool being (int)1 and
VIR_QEMU_PROCESS_KILL_FORCE having the value of 1 << 0.  The check was
then moved and altered in 8fd38231 to
current state:

if ((i == 50) & force)

that will work again (both sides of '&' being booleans), but since this
was missed so many times, it may pose a problem in the future in case it
gets copy-pasted again.
Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

A cygwin build of 1.2.9 fails with:

util/virprocess.c:87:27: fatal error: sys/syscall.h: No such file or directory
 #  include <sys/syscall.h>

But in reality, the ONLY user of setns() is lxc, which is Linux-only.
It's easiest to just limit the setns workarounds to Linux.

* src/util/virprocess.c (setns): Limit definition to Linux.
Signed-off-by: NEric Blake <eblake@redhat.com>

Currently, the setns() wrapper is supported only for x86_64 and i686
which leaves us failing to build on other platforms like arm, aarch64
and so on. This means, that the wrapper needs to be extended to those
platforms and make to fail on runtime not compile time.

The syscall numbers for other platforms was fetched using this
command:

kernel.git $ git grep "define.*__NR_setns" | grep -e arm -e powerpc -e s390
arch/arm/include/uapi/asm/unistd.h:#define __NR_setns                   (__NR_SYSCALL_BASE+375)
arch/arm64/include/asm/unistd32.h:#define __NR_setns 375
arch/powerpc/include/uapi/asm/unistd.h:#define __NR_setns               350
arch/s390/include/uapi/asm/unistd.h:#define __NR_setns          339
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

The build failed because of missing "sys/syscall.h".
Signed-off-by: NPavel Hrdina <phrdina@redhat.com>

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.htmlSigned-off-by: NStephan Sachse <ste.sachse@gmail.com>
Signed-off-by: NMichal 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.

s/forcably/forcibly
Signed-off-by: NHongwei Bi <hwbi2008@gmail.com>
Signed-off-by: NEric Blake <eblake@redhat.com>

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: NDaniel 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: NEric 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: NEric 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: NEric 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: NEric 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=732394Signed-off-by: NDaniel Berrange <berrange@redhat.com>
Signed-off-by: NEric Blake <eblake@redhat.com>

Check for presence of sys/cpuset.h header and cpuset_getaffinity()
in configure instead of just using #ifdef __FreeBSD__ for that code.

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: NDaniel 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: NRichard Weinberger <richard@nod.at>
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>