On Tue, Jun 14, 2011 at 10:15:36AM +0100, Daniel P. Berrange wrote:
> On Tue, Jun 07, 2011 at 10:02:55AM +0900, Minoru Usui wrote:
> > virNodeGetCPUStats: Implement linux support
> >
> > Signed-off-by: Minoru Usui <usui@xxxxxxxxxxxxxxxxx>
> > ---
> > src/libvirt_private.syms | 1 +
> > src/lxc/lxc_driver.c | 1 +
> > src/nodeinfo.c | 138 ++++++++++++++++++++++++++++++++++++++++++++++
> > src/nodeinfo.h | 6 ++-
> > src/qemu/qemu_driver.c | 1 +
> > src/uml/uml_driver.c | 1 +
> > 6 files changed, 147 insertions(+), 1 deletions(-)
> >
> > diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
> > index e6ab870..a8c77f2 100644
> > --- a/src/libvirt_private.syms
> > +++ b/src/libvirt_private.syms
> > @@ -731,6 +731,7 @@ virNodeDeviceObjUnlock;
> >
> > # nodeinfo.h
> > nodeCapsInitNUMA;
> > +nodeGetCPUStats;
> > nodeGetCellsFreeMemory;
> > nodeGetFreeMemory;
> > nodeGetInfo;
> > diff --git a/src/lxc/lxc_driver.c b/src/lxc/lxc_driver.c
> > index 8eb87a2..3286154 100644
> > --- a/src/lxc/lxc_driver.c
> > +++ b/src/lxc/lxc_driver.c
> > @@ -2779,6 +2779,7 @@ static virDriver lxcDriver = {
> > .domainSetSchedulerParameters = lxcSetSchedulerParameters, /* 0.5.0 */
> > .domainSetSchedulerParametersFlags = lxcSetSchedulerParametersFlags, /* 0.9.2 */
> > .domainInterfaceStats = lxcDomainInterfaceStats, /* 0.7.3 */
> > + .nodeGetCPUStats = nodeGetCPUStats, /* 0.9.3 */
> > .nodeGetCellsFreeMemory = nodeGetCellsFreeMemory, /* 0.6.5 */
> > .nodeGetFreeMemory = nodeGetFreeMemory, /* 0.6.5 */
> > .domainEventRegister = lxcDomainEventRegister, /* 0.7.0 */
> > diff --git a/src/nodeinfo.c b/src/nodeinfo.c
> > index f55c83e..39afd0e 100644
> > --- a/src/nodeinfo.c
> > +++ b/src/nodeinfo.c
> > @@ -57,12 +57,20 @@
> > #ifdef __linux__
> > # define CPUINFO_PATH "/proc/cpuinfo"
> > # define CPU_SYS_PATH "/sys/devices/system/cpu"
> > +# define PROCSTAT_PATH "/proc/stat"
> > +
> > +# define LINUX_NB_CPU_STATS 4
> >
> > /* NB, this is not static as we need to call it from the testsuite */
> > int linuxNodeInfoCPUPopulate(FILE *cpuinfo,
> > virNodeInfoPtr nodeinfo,
> > bool need_hyperthreads);
> >
> > +int linuxNodeGetCPUStats(FILE *procstat,
> > + int cpuNum,
> > + virCPUStatsPtr params,
> > + int *nparams);
> > +
> > /* Return the positive decimal contents of the given
> > * CPU_SYS_PATH/cpu%u/FILE, or -1 on error. If MISSING_OK and the
> > * file could not be found, return 1 instead of an error; this is
> > @@ -378,6 +386,108 @@ int linuxNodeInfoCPUPopulate(FILE *cpuinfo,
> > return 0;
> > }
> >
> > +#define TICK_TO_NSEC (1000ull * 1000ull * 1000ull / sysconf(_SC_CLK_TCK))
> > +#define CPU_HEADER_LEN 8
> > +
> > +int linuxNodeGetCPUStats(FILE *procstat,
> > + int cpuNum,
> > + virCPUStatsPtr params,
> > + int *nparams)
> > +{
> > + int ret = -1;
> > + char line[1024];
> > + unsigned long long usr, ni, sys, idle, iowait;
> > + unsigned long long irq, softirq, steal, guest, guest_nice;
> > + char cpu_header[CPU_HEADER_LEN];
> > +
> > + if ((*nparams) == 0) {
> > + /* Current number of cpu stats supported by linux */
> > + *nparams = LINUX_NB_CPU_STATS;
> > + ret = 0;
> > + goto cleanup;
> > + }
> > +
> > + if ((*nparams) != LINUX_NB_CPU_STATS) {
> > + nodeReportError(VIR_ERR_INVALID_ARG,
> > + "%s", _("Invalid parameter count"));
> > + goto cleanup;
> > + }
> > +
> > + if (cpuNum == VIR_CPU_STATS_ALL_CPUS) {
> > + strcpy(cpu_header, "cpu");
> > + } else {
> > + sprintf(cpu_header, "cpu%d", cpuNum);
> > + }
>
> cpu_header is declared to be 8 bytes in size, which only allows
> for integers upto 4 digits long, before we get a buffer overflow
> here.
>
> gnulib has some macro which can be used to declare a string buffer
> large enough to hold an integer, but I can't remember what the
> macro is called right now. Hopefully Eric will remind us shortly....
Jim Meyering reminded me that it is INT_BUFSIZE_BOUND. So eg you
want todo
char cpu_header[3 + INT_BUFSIZE_BOUND(cpuNum) + 1];
to allow enough space for 'cpu' + any cpuNum value formatted as
a string + the trailing NULL.
Regards,
Daniel
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