Current File : //proc/self/root/bin/fix_grub_config_on_xen_pv
#!/usr/bin/python
import os
import re
import subprocess
import sys
KERNELS_TO_REMOVE = ['3.10.0-714.10.2.lve1.5.9', '3.10.0-714.10.2.lve1.5.8',
'3.10.0-714.10.2.lve1.4.80', '3.10.0-714.10.2.lve1.4.79',
'2.6.32-896.16.1.lve1.4.50', '2.6.32-896.16.1.lve1.4.49',
'2.6.32-896.16.1.lve1.4.48', '2.6.32-896.16.1.lve1.4.51']
SUGGESTED_KERNELS = {'cl6': 'kernel-2.6.32-896.16.1.lve1.4.46.el6',
'cl7_reseller': 'kernel-3.10.0-714.10.2.lve1.5.7.el7',
'cl6h_reseller': 'kernel-3.10.0-714.10.2.lve1.5.7.el6h',
'cl7': 'kernel-3.10.0-714.10.2.lve1.4.78.el7'}
def run_shell_cmd(cmd):
return subprocess.Popen(cmd, stdout=subprocess.PIPE, shell=True).communicate()
def remove_kernel_from_grub(kernel_ver):
grubby_cmd = 'grubby --remove-kernel=/boot/vmlinuz-%s' % kernel_ver
print u'Removing kernel %s as it contains Meltdown fix which currently doesn\'t work on Xen PV' % kernel_ver
run_shell_cmd(grubby_cmd)
def detect_xen_pv():
out, _ = run_shell_cmd('virt-what')
if 'xen' in out:
has_pci = os.listdir('/sys/bus/pci/devices')
if not has_pci:
return True
return False
return False
def get_kernel_versions():
# We're assuming that every kernel should have its initramfs file
initrd_re = re.compile('^initramfs-\w.+.img$')
ver_re = re.compile('\d.+-\d.+lve\d.\d.\d+.el\w+.(x86_64|i686)')
initrd_list = [item for item in os.listdir('/boot') if initrd_re.match(item)]
ver_list = []
for item in initrd_list:
ver = ver_re.search(item)
if ver:
ver_list.append(ver.group())
return set(ver_list)
def get_dist_version():
current_kernel, _ = run_shell_cmd('uname -r')
current_kernel = current_kernel.strip()
if '2.6.32' in current_kernel:
return 'cl6'
elif '3.10.0' in current_kernel:
if 'lve1.5' in current_kernel and '.el6h' in current_kernel:
return 'cl6h_reseller'
elif '.el6h' in current_kernel:
return 'cl6h'
elif 'lve1.5' in current_kernel:
return 'cl7_reseller'
else:
return 'cl7'
else:
raise Exception('Unknown kernel version')
if __name__ == '__main__':
is_xen_pv = detect_xen_pv()
kernel_vers = get_kernel_versions()
dist = get_dist_version()
if is_xen_pv and kernel_vers and kernel_vers.issubset(KERNELS_TO_REMOVE):
print u'WARNING: your system has only kernels with fix for Meltdown/Spectre attacks installed, you will not be able to boot after reboot'
print u'Please install % kernel to avoid this problem' % SUGGESTED_KERNELS[dist]
sys.exit(0)
if is_xen_pv:
print u'Your system is detected like Xen PV instance'
print u'Checking if any kernels with Meltdown fix are installed on the system'
for kernel_ver in kernel_vers:
if any([item in kernel_ver for item in KERNELS_TO_REMOVE]):
remove_kernel_from_grub(kernel_ver)
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