[libvirt] [PATCH] virhostuptime: Add linux stub for musl

[Cole Robinson]

On 10/14/19 10:57 AM, Michal Privoznik wrote:
> When we want to know the boot timestamp of the host, we can call
> virHostGetBootTime(). Under the hood, it uses getutxid() which is
> defined by POSIX and properly check for in configure. However,
> musl took a path where it declares the function but instead of
> providing any useful implementation it returns NULL meaning "no
> record found". If that's the case, use our second best option -
> /proc/uptime and a bit of maths.
> 
> https://bugzilla.redhat.com/show_bug.cgi?id=1760885
> 
> Signed-off-by: Michal Privoznik <mprivozn at redhat.com>
> ---
>  src/util/virhostuptime.c | 64 ++++++++++++++++++++++++++++++++++++++--
>  1 file changed, 61 insertions(+), 3 deletions(-)
> 
> diff --git a/src/util/virhostuptime.c b/src/util/virhostuptime.c
> index 62b781acd5..3189074d3d 100644
> --- a/src/util/virhostuptime.c
> +++ b/src/util/virhostuptime.c
> @@ -25,16 +25,68 @@
>  #endif
>  
>  #include "virhostuptime.h"
> +#include "viralloc.h"
> +#include "virfile.h"
> +#include "virlog.h"
> +#include "virstring.h"
> +#include "virtime.h"
>  #include "virthread.h"
>  
> +#define VIR_FROM_THIS VIR_FROM_NONE
> +
> +VIR_LOG_INIT("util.virhostuptime");
> +
>  static unsigned long long bootTime;
>  static int bootTimeErrno;
>  static virOnceControl virHostGetBootTimeOnce = VIR_ONCE_CONTROL_INITIALIZER;
>  
> -#ifdef HAVE_GETUTXID
> +#if defined(__linux__)
> +# define UPTIME_FILE  "/proc/uptime"
> +static int
> +virHostGetBootTimeProcfs(unsigned long long *btime)
> +{
> +    unsigned long long now;
> +    double up;
> +    g_autofree char *buf = NULL;
> +    char *tmp;
> +
> +    if (virTimeMillisNow(&now) < 0)
> +        return -errno;
> +
> +    /* 1KiB limit is more than enough. */
> +    if (virFileReadAll(UPTIME_FILE, 1024, &buf) < 0)
> +        return -errno;
> +
> +    /* buf contains two doubles now:
> +     *   $uptime $idle_time
> +     * We're interested only in the first one */
> +    if (!(tmp = strchr(buf, ' '))) {
> +        virReportError(VIR_ERR_INTERNAL_ERROR,
> +                       _("uptime file has unexpected format '%s'"),
> +                       buf);
> +        return -EINVAL;
> +    }
> +
> +    *tmp = '\0';
> +
> +    if (virStrToDouble(buf, NULL, &up) < 0) {
> +        virReportError(VIR_ERR_INTERNAL_ERROR,
> +                       _("Unable to parse sched info value '%s'"),
> +                       buf);
> +        return -EINVAL;
> +    }
> +

error message here is a copy+paste mistake. syntax-check says you need
to extend POTFILES.in too. With those fixed:

Reviewed-by: Cole Robinson <crobinso at redhat.com>

- Cole