1. 27 3月, 2019 2 次提交
    • D
      seccomp: don't kill process for resource control syscalls · 9a1565a0
      Daniel P. Berrangé 提交于
      The Mesa library tries to set process affinity on some of its threads in
      order to optimize its performance. Currently this results in QEMU being
      immediately terminated when seccomp is enabled.
      
      Mesa doesn't consider failure of the process affinity settings to be
      fatal to its operation, but our seccomp policy gives it no choice in
      gracefully handling this denial.
      
      It is reasonable to consider that malicious code using the resource
      control syscalls to be a less serious attack than if they were trying
      to spawn processes or change UIDs and other such things. Generally
      speaking changing the resource control setting will "merely" affect
      quality of service of processes on the host. With this in mind, rather
      than kill the process, we can relax the policy for these syscalls to
      return the EPERM errno value. This allows callers to detect that QEMU
      does not want them to change resource allocations, and apply some
      reasonable fallback logic.
      
      The main downside to this is for code which uses these syscalls but does
      not check the return value, blindly assuming they will always
      succeeed. Returning an errno could result in sub-optimal behaviour.
      Arguably though such code is already broken & needs fixing regardless.
      Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>
      Reviewed-by: NMarc-André Lureau <marcandre.lureau@redhat.com>
      Signed-off-by: NEduardo Otubo <otubo@redhat.com>
      9a1565a0
    • P
      Update version for v4.0.0-rc1 release · 49fc899f
      Peter Maydell 提交于
      Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
      49fc899f
  2. 26 3月, 2019 38 次提交