[PATCH v6 5/6] Improve debugging in the kdump kernel

[Lianbo Jiang]

Let's use the logger in the second kernel and collect the kernel ring
buffer(dmesg) of the second kernel.

Signed-off-by: Lianbo Jiang <lijiang(a)redhat.com&gt;
---
 dracut-kdump.sh        | 68 +++++++++++++++++++++++++-----------------
 dracut-module-setup.sh |  4 +++
 kdump-lib-initramfs.sh | 67 ++++++++++++++++++++++++++++++-----------
 3 files changed, 95 insertions(+), 44 deletions(-)

diff --git a/dracut-kdump.sh b/dracut-kdump.sh
index 6f948fce026f..c2627c296040 100755
--- a/dracut-kdump.sh
+++ b/dracut-kdump.sh
@@ -5,7 +5,6 @@ if [ -f /etc/fadump.initramfs ] && [ ! -f
/proc/device-tree/rtas/ibm,kernel-dump
     exit 0
 fi
 
-exec &> /dev/console
 . /lib/dracut-lib.sh
 . /lib/kdump-lib-initramfs.sh
 
@@ -22,7 +21,7 @@ do_dump()
     _ret=$?
 
     if [ $_ret -ne 0 ]; then
-        echo "kdump: saving vmcore failed"
+        derror "saving vmcore failed"
     fi
 
     return $_ret
@@ -36,7 +35,7 @@ do_kdump_pre()
         "$KDUMP_PRE"
         _ret=$?
         if [ $_ret -ne 0 ]; then
-            echo "kdump: $KDUMP_PRE exited with $_ret status"
+            derror "$KDUMP_PRE exited with $_ret status"
             return $_ret
         fi
     fi
@@ -47,7 +46,7 @@ do_kdump_pre()
             "$file"
             _ret=$?
             if [ $_ret -ne 0 ]; then
-                echo "kdump: $file exited with $_ret status"
+                derror "$file exited with $_ret status"
             fi
         done
     fi
@@ -63,7 +62,7 @@ do_kdump_post()
             "$file" "$1"
             _ret=$?
             if [ $_ret -ne 0 ]; then
-                echo "kdump: $file exited with $_ret status"
+                derror "$file exited with $_ret status"
             fi
         done
     fi
@@ -72,7 +71,7 @@ do_kdump_post()
         "$KDUMP_POST" "$1"
         _ret=$?
         if [ $_ret -ne 0 ]; then
-            echo "kdump: $KDUMP_POST exited with $_ret status"
+            derror "$KDUMP_POST exited with $_ret status"
         fi
     fi
 }
@@ -88,7 +87,7 @@ dump_raw()
 
     [ -b "$_raw" ] || return 1
 
-    echo "kdump: saving to raw disk $_raw"
+    dinfo "saving to raw disk $_raw"
 
     if ! $(echo -n $CORE_COLLECTOR|grep -q makedumpfile); then
         _src_size=`ls -l /proc/vmcore | cut -d' ' -f5`
@@ -96,21 +95,22 @@ dump_raw()
         monitor_dd_progress $_src_size_mb &
     fi
 
-    echo "kdump: saving vmcore"
+    dinfo "saving vmcore"
     $CORE_COLLECTOR /proc/vmcore | dd of=$_raw bs=$DD_BLKSIZE >>
/tmp/dd_progress_file 2>&1 || return 1
     sync
 
-    echo "kdump: saving vmcore complete"
+    dinfo "saving vmcore complete"
     return 0
 }
 
 dump_ssh()
 {
+    local ret
     local _opt="-i $1 -o BatchMode=yes -o StrictHostKeyChecking=yes"
     local _dir="$KDUMP_PATH/$HOST_IP-$DATEDIR"
     local _host=$2
 
-    echo "kdump: saving to $_host:$_dir"
+    dinfo "saving to $_host:$_dir"
 
     cat /var/lib/random-seed > /dev/urandom
     ssh -q $_opt $_host mkdir -p $_dir || return 1
@@ -118,17 +118,29 @@ dump_ssh()
     save_vmcore_dmesg_ssh ${DMESG_COLLECTOR} ${_dir} "${_opt}" $_host
     save_opalcore_ssh ${_dir} "${_opt}" $_host
 
-    echo "kdump: saving vmcore"
+    dinfo "saving vmcore"
 
     if [ "${CORE_COLLECTOR%%[[:blank:]]*}" = "scp" ]; then
-        scp -q $_opt /proc/vmcore "$_host:$_dir/vmcore-incomplete" || return 1
+        scp -q $_opt /proc/vmcore "$_host:$_dir/vmcore-incomplete"
+        ret=$?
+        save_log
+        scp -q $_opt $KDUMP_LOG_FILE "$_host:$_dir/"
+        if [ $ret -ne 0 ]; then
+            return 1
+        fi
         ssh $_opt $_host "mv $_dir/vmcore-incomplete $_dir/vmcore" || return 1
     else
-        $CORE_COLLECTOR /proc/vmcore | ssh $_opt $_host "dd bs=512
of=$_dir/vmcore-incomplete" || return 1
+        $CORE_COLLECTOR /proc/vmcore | ssh $_opt $_host "dd bs=512
of=$_dir/vmcore-incomplete"
+        ret=$?
+        save_log
+        scp -q $_opt $KDUMP_LOG_FILE "$_host:$_dir/"
+        if [ $ret -ne 0 ]; then
+            return 1
+        fi
         ssh $_opt $_host "mv $_dir/vmcore-incomplete $_dir/vmcore.flat" ||
return 1
     fi
 
-    echo "kdump: saving vmcore complete"
+    dinfo "saving vmcore complete"
     return 0
 }
 
@@ -137,6 +149,8 @@ save_opalcore_ssh() {
     local _opts="$2"
     local _location=$3
 
+    ddebug "_path=$_path _opts=$_opts _location=$_location"
+
     if [ ! -f $OPALCORE ]; then
         # Check if we are on an old kernel that uses a different path
         if [ -f /sys/firmware/opal/core ]; then
@@ -146,15 +160,15 @@ save_opalcore_ssh() {
         fi
     fi
 
-    echo "kdump: saving opalcore"
+    dinfo "saving opalcore:$OPALCORE to $_location:$_path"
     scp $_opts $OPALCORE $_location:$_path/opalcore-incomplete
     if [ $? -ne 0 ]; then
-        echo "kdump: saving opalcore failed"
+        derror "saving opalcore failed"
        return 1
     fi
 
     ssh $_opts $_location mv $_path/opalcore-incomplete $_path/opalcore
-    echo "kdump: saving opalcore complete"
+    dinfo "saving opalcore complete"
     return 0
 }
 
@@ -164,15 +178,15 @@ save_vmcore_dmesg_ssh() {
     local _opts="$3"
     local _location=$4
 
-    echo "kdump: saving vmcore-dmesg.txt"
+    dinfo "saving vmcore-dmesg.txt to $_location:$_path"
     $_dmesg_collector /proc/vmcore | ssh $_opts $_location "dd
of=$_path/vmcore-dmesg-incomplete.txt"
     _exitcode=$?
 
     if [ $_exitcode -eq 0 ]; then
         ssh -q $_opts $_location mv $_path/vmcore-dmesg-incomplete.txt
$_path/vmcore-dmesg.txt
-        echo "kdump: saving vmcore-dmesg.txt complete"
+        dinfo "saving vmcore-dmesg.txt complete"
     else
-        echo "kdump: saving vmcore-dmesg.txt failed"
+        derror "saving vmcore-dmesg.txt failed"
     fi
 }
 
@@ -182,12 +196,12 @@ get_host_ip()
     if is_nfs_dump_target || is_ssh_dump_target
     then
         kdumpnic=$(getarg kdumpnic=)
-        [ -z "$kdumpnic" ] && echo "kdump: failed to get
kdumpnic!" && return 1
+        [ -z "$kdumpnic" ] && derror "failed to get
kdumpnic!" && return 1
         _host=`ip addr show dev $kdumpnic|grep '[ ]*inet'`
-        [ $? -ne 0 ] && echo "kdump: wrong kdumpnic: $kdumpnic"
&& return 1
+        [ $? -ne 0 ] && derror "wrong kdumpnic: $kdumpnic" &&
return 1
         _host=`echo $_host | head -n 1 | cut -d' ' -f2`
         _host="${_host%%/*}"
-        [ -z "$_host" ] && echo "kdump: wrong kdumpnic:
$kdumpnic" && return 1
+        [ -z "$_host" ] && derror "wrong kdumpnic: $kdumpnic"
&& return 1
         HOST_IP=$_host
     fi
     return 0
@@ -196,7 +210,7 @@ get_host_ip()
 read_kdump_conf()
 {
     if [ ! -f "$KDUMP_CONF" ]; then
-        echo "kdump: $KDUMP_CONF not found"
+        derror "$KDUMP_CONF not found"
         return
     fi
 
@@ -240,7 +254,7 @@ fence_kdump_notify
 
 get_host_ip
 if [ $? -ne 0 ]; then
-    echo "kdump: get_host_ip exited with non-zero status!"
+    derror "get_host_ip exited with non-zero status!"
     exit 1
 fi
 
@@ -250,7 +264,7 @@ fi
 
 do_kdump_pre
 if [ $? -ne 0 ]; then
-    echo "kdump: kdump_pre script exited with non-zero status!"
+    derror "kdump_pre script exited with non-zero status!"
     do_final_action
     # During systemd service to reboot the machine, stop this shell script running
     exit 1
@@ -261,7 +275,7 @@ DUMP_RETVAL=$?
 
 do_kdump_post $DUMP_RETVAL
 if [ $? -ne 0 ]; then
-    echo "kdump: kdump_post script exited with non-zero status!"
+    derror "kdump_post script exited with non-zero status!"
 fi
 
 if [ $DUMP_RETVAL -ne 0 ]; then
diff --git a/dracut-module-setup.sh b/dracut-module-setup.sh
index a186570f5673..b0b30af0ae8f 100755
--- a/dracut-module-setup.sh
+++ b/dracut-module-setup.sh
@@ -818,6 +818,7 @@ install() {
         kdump_install_random_seed
     fi
     dracut_install -o /etc/adjtime /etc/localtime
+    inst_simple "/etc/sysconfig/kdump"
     inst "$moddir/monitor_dd_progress"
"/kdumpscripts/monitor_dd_progress"
     chmod +x ${initdir}/kdumpscripts/monitor_dd_progress
     inst "/bin/dd" "/bin/dd"
@@ -830,8 +831,11 @@ install() {
     inst "/bin/sed" "/bin/sed"
     inst "/sbin/makedumpfile" "/sbin/makedumpfile"
     inst "/sbin/vmcore-dmesg" "/sbin/vmcore-dmesg"
+    inst "/usr/bin/printf" "/sbin/printf"
+    inst "/usr/bin/logger" "/sbin/logger"
     inst "/lib/kdump/kdump-lib.sh" "/lib/kdump-lib.sh"
     inst "/lib/kdump/kdump-lib-initramfs.sh"
"/lib/kdump-lib-initramfs.sh"
+    inst "/lib/kdump/kdump-logger.sh" "/lib/kdump-logger.sh"
     inst "$moddir/kdump.sh" "/usr/bin/kdump.sh"
     inst "$moddir/kdump-capture.service"
"$systemdsystemunitdir/kdump-capture.service"
     mkdir -p "$initdir/$systemdsystemunitdir/initrd.target.wants"
diff --git a/kdump-lib-initramfs.sh b/kdump-lib-initramfs.sh
index 8ef3cd00615a..12bf44a72fcc 100755
--- a/kdump-lib-initramfs.sh
+++ b/kdump-lib-initramfs.sh
@@ -1,8 +1,11 @@
 # These variables and functions are useful in 2nd kernel
 
 . /lib/kdump-lib.sh
+. /etc/sysconfig/kdump
+. /lib/kdump-logger.sh
 
 KDUMP_PATH="/var/crash"
+KDUMP_LOG_FILE="/run/initramfs/kexec-dmesg.log"
 CORE_COLLECTOR=""
 DEFAULT_CORE_COLLECTOR="makedumpfile -l --message-level 7 -d 31"
 DMESG_COLLECTOR="/sbin/vmcore-dmesg"
@@ -20,6 +23,13 @@ KDUMP_POST=""
 NEWROOT="/sysroot"
 OPALCORE="/sys/firmware/opal/mpipl/core"
 
+#initiate the kdump logger
+dlog_init
+if [ $? -ne 0 ]; then
+    echo "failed to initiate the kdump logger."
+    exit 1
+fi
+
 get_kdump_confs()
 {
     local config_opt config_val
@@ -94,27 +104,40 @@ get_kdump_confs()
     fi
 }
 
+# store the kexec kernel log to a file.
+save_log()
+{
+    if command -v journalctl > /dev/null; then
+        journalctl -ab > $KDUMP_LOG_FILE
+    else
+        dmesg > $KDUMP_LOG_FILE
+    fi
+}
+
 # dump_fs <mount point>
 dump_fs()
 {
+    local ret
     local _mp=$1
     local _dev=$(get_mount_info SOURCE target $_mp -f)
     local _op=$(get_mount_info OPTIONS target $_mp -f)
 
+    ddebug "_mp=$_mp _dev=$_dev _op=$_op"
+
     # If dump path have a corresponding device entry but not mounted, mount it.
     if [ -n "$_dev" ]; then
         if ! is_mounted "$_mp"; then
-            echo "kdump: dump target $_dev is not mounted, trying to mount..."
+            dinfo "dump target $_dev is not mounted, trying to mount..."
             mkdir -p $_mp
             mount -o $_op $_dev $_mp
 
             if [ $? -ne 0 ]; then
-                echo "kdump: mounting failed (mount point: $_mp, option:
$_op)"
+                derror "mounting failed (mount point: $_mp, option: $_op)"
                 return 1
             fi
         fi
     else
-        echo "kdump: failed to dump to \"$_mp\", it's not a mount
point!"
+        derror "failed to dump to \"$_mp\", it's not a mount
point!"
         return 1
     fi
 
@@ -123,11 +146,11 @@ dump_fs()
 
     local _dump_path=$(echo "$_mp/$KDUMP_PATH/$HOST_IP-$DATEDIR/" | tr -s /)
 
-    echo "kdump: saving to $_dump_path"
+    dinfo "saving to $_dump_path"
 
     # Only remount to read-write mode if the dump target is mounted read-only.
     if [[ "$_op" = "ro"* ]]; then
-       echo "kdump: Mounting Dump target $_dev in rw mode."
+       dinfo "Mounting Dump target $_dev in rw mode."
        mount -o remount,rw $_dev $_mp || return 1
     fi
 
@@ -136,12 +159,18 @@ dump_fs()
     save_vmcore_dmesg_fs ${DMESG_COLLECTOR} "$_dump_path"
     save_opalcore_fs "$_dump_path"
 
-    echo "kdump: saving vmcore"
-    $CORE_COLLECTOR /proc/vmcore $_dump_path/vmcore-incomplete || return 1
+    dinfo "saving vmcore"
+    $CORE_COLLECTOR /proc/vmcore $_dump_path/vmcore-incomplete
+    ret=$?
+    save_log
+    mv $KDUMP_LOG_FILE $_dump_path/
+    if [ $ret -ne 0 ]; then
+	    return 1
+    fi
     mv $_dump_path/vmcore-incomplete $_dump_path/vmcore
     sync
 
-    echo "kdump: saving vmcore complete"
+    dinfo "saving vmcore complete"
 
     # improper kernel cmdline can cause the failure of echo, we can ignore this kind of
failure
     return 0
@@ -151,7 +180,7 @@ save_vmcore_dmesg_fs() {
     local _dmesg_collector=$1
     local _path=$2
 
-    echo "kdump: saving vmcore-dmesg.txt"
+    dinfo "saving vmcore-dmesg.txt to ${_path}"
     $_dmesg_collector /proc/vmcore > ${_path}/vmcore-dmesg-incomplete.txt
     _exitcode=$?
     if [ $_exitcode -eq 0 ]; then
@@ -161,9 +190,9 @@ save_vmcore_dmesg_fs() {
         # saving vmcore failed and system rebooted without sync and there
         # was no vmcore-dmesg.txt available.
         sync
-        echo "kdump: saving vmcore-dmesg.txt complete"
+        dinfo "saving vmcore-dmesg.txt complete"
     else
-        echo "kdump: saving vmcore-dmesg.txt failed"
+        derror "saving vmcore-dmesg.txt failed"
     fi
 }
 
@@ -179,43 +208,47 @@ save_opalcore_fs() {
         fi
     fi
 
-    echo "kdump: saving opalcore"
+    dinfo "saving opalcore:$OPALCORE to ${_path}/opalcore"
     cp $OPALCORE ${_path}/opalcore
     if [ $? -ne 0 ]; then
-        echo "kdump: saving opalcore failed"
+        derror "saving opalcore failed"
         return 1
     fi
 
     sync
-    echo "kdump: saving opalcore complete"
+    dinfo "saving opalcore complete"
     return 0
 }
 
 dump_to_rootfs()
 {
 
-    echo "Kdump: trying to bring up rootfs device"
+    dinfo "Trying to bring up rootfs device"
     systemctl start dracut-initqueue
-    echo "Kdump: waiting for rootfs mount, will timeout after 90 seconds"
+    dinfo "Waiting for rootfs mount, will timeout after 90 seconds"
     systemctl start sysroot.mount
 
+    ddebug "NEWROOT=$NEWROOT"
+
     dump_fs $NEWROOT
 }
 
 kdump_emergency_shell()
 {
     echo "PS1=\"kdump:\\\${PWD}# \"" >/etc/profile
+    ddebug "Switching to dracut emergency..."
     /bin/dracut-emergency
     rm -f /etc/profile
 }
 
 do_failure_action()
 {
-    echo "Kdump: Executing failure action $FAILURE_ACTION"
+    dinfo "Executing failure action $FAILURE_ACTION"
     eval $FAILURE_ACTION
 }
 
 do_final_action()
 {
+    dinfo "Executing final action $FINAL_ACTION"
     eval $FINAL_ACTION
 }
-- 
2.17.1