net-test: try to detect vsyscall=none uml and warn about it.
Bug: 123953923
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: Ib05019a1db10fbaae4bf4aa5000d8c617b9837d5
diff --git a/net/test/run_net_test.sh b/net/test/run_net_test.sh
index 17b44d9..a81ad33 100755
--- a/net/test/run_net_test.sh
+++ b/net/test/run_net_test.sh
@@ -306,9 +306,32 @@
blockdevice=ubdar
fi
+ exitcode=0
$KERNEL_BINARY >&2 umid=net_test mem=512M \
- $blockdevice=$SCRIPT_DIR/$ROOTFS $netconfig $consolemode $cmdline
- exitcode=$?
+ $blockdevice=$SCRIPT_DIR/$ROOTFS $netconfig $consolemode $cmdline \
+ || exitcode=$?
+
+ # UML is kind of crazy in how guest syscalls work. It requires host kernel
+ # to not be in vsyscall=none mode.
+ if [[ "${exitcode}" != '0' ]]; then
+ {
+ # Hopefully one of these exists
+ cat /proc/config || :
+ zcat /proc/config.gz || :
+ cat "/boot/config-$(uname -r)" || :
+ zcat "/boot/config-$(uname -r).gz" || :
+ } 2>/dev/null \
+ | egrep -q '^CONFIG_LEGACY_VSYSCALL_NONE=y' \
+ && ! egrep -q '(^| )vsyscall=(native|emulate)( |$)' /proc/cmdline \
+ && {
+ echo '-----=====-----'
+ echo 'If above you saw a "net_test.sh[1]: segfault at ..." followed by'
+ echo '"Kernel panic - not syncing: Attempted to kill init!" then please'
+ echo 'set "vsyscall=emulate" on *host* kernel command line.'
+ echo '(for example via GRUB_CMDLINE_LINUX in /etc/default/grub)'
+ echo '-----=====-----'
+ }
+ fi
else
# We boot into the filesystem image directly in all cases
cmdline="$cmdline root=/dev/vda"
