kexec May 2017

kexec@lists.fedoraproject.org

11 participants
20 discussions

[PATCH] kdumpctl: use "apicid" other than "initial apicid"
by Xunlei Pang 13 Jul '17

13 Jul '17

We met a problem on AMD machines, when using "nr_cpus=4" for kdump, and crash happens on cpus other than cpu0, kdump kernel will fail to boot and eventually reset. After some debugging, we found that it stuck at the kernel path do_boot_cpu()-> ... ->wakeup_secondary_cpu_via_init(): apic_icr_write(APIC_INT_LEVELTRIG|APIC_INT_ASSERT|APIC_DM_INIT, phys_apicid); that is, it stuck at sending INIT from AP to BP and reset, which is actually what "disable_cpu_apicid=X" tries to solve. Printing the value of @phys_apicid showed that it was the value of "apicid" other that of "initial apicid" showed by /proc/cpuinfo. As described in x86 specification: "In MP systems, the local APIC ID is also used as a processor ID by the BIOS and the operating system. Some processors permit software to modify the APIC ID. However, the ability of software to modify the APIC ID is processor model specific. Because of this, operating system software should avoid writing to the local APIC ID register. The value returned by bits 31-24 of the EBX register (when the CPUID instruction is executed with a source operand value of 1 in the EAX register) is always the Initial APIC ID (determined by the platform initialization). This is true even if software has changed the value in the Local APIC ID register." From kernel commit 151e0c7de("x86, apic, kexec: Add disable_cpu_apicid kernel parameter"), we can see in generic_processor_info(), it uses a)read_apic_id() and b)@apicid to compare with @disabled_cpu_apicid. a)@apicid which is actually @phys_apicid above-mentioned is from the following calltrace(on the problematic AMD machine): generic_processor_info+0x37/0x300 acpi_register_lapic+0x30/0x90 acpi_parse_lapic+0x40/0x50 acpi_table_parse_entries_array+0x171/0x1de acpi_boot_init+0xed/0x50f The value of @apicid(from acpi MADT) is equal to the value of "apicid" showed by /proc/cpuinfo as proved by our debug printk. b)read_apic_id() gets the value from LAPIC ID register which is "apicid" as well. While the value of "initial apicid" is from cpuid instruction. One example of "apicid" and "initial apicid" of cpu0 from /proc/cpuinfo on AMD machine: apicid : 32 initial apicid : 0 Therefore, we should assign /proc/cpuifo "apicid" to "disable_cpu_apicid=X". We've never met such issue before, because we usually tested "nr_cpus=1", and mostly on Intel machines, and "apicid" and "initial apicid" have the same value in most cases on Intel machines. Signed-off-by: Xunlei Pang <xlpang(a)redhat.com> --- kdumpctl | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/kdumpctl b/kdumpctl index 4d6b3e8..46b65d2 100755 --- a/kdumpctl +++ b/kdumpctl @@ -77,15 +77,15 @@ remove_cmdline_param() } # -# This function returns the "initial apicid" of the -# boot cpu (cpu 0) if present. +# This function returns the "apicid" of the boot +# cpu (cpu 0) if present. # -get_bootcpu_initial_apicid() +get_bootcpu_apicid() { awk ' \ BEGIN { CPU = "-1"; } \ $1=="processor" && $2==":" { CPU = $NF; } \ - CPU=="0" && /initial apicid/ { print $NF; } \ + CPU=="0" && /^apicid/ { print $NF; } \ ' \ /proc/cpuinfo } @@ -206,7 +206,7 @@ prepare_cmdline() cmdline="${cmdline} ${KDUMP_COMMANDLINE_APPEND}" - id=`get_bootcpu_initial_apicid` + id=`get_bootcpu_apicid` if [ ! -z ${id} ] ; then cmdline=`append_cmdline "${cmdline}" disable_cpu_apicid ${id}` fi -- 1.8.3.1

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[PATCH] dracut-module-setup: Fix test for inclusion of DRM modules
by Benjamin Berg 14 Jun '17

14 Jun '17

The /sys/modules/*/drivers sysfs entries do not exist anymore on newer kernels which means that the DRM moduels would never be included. Instead check if there is any device with a "drm" sysfs directory to decide on whether DRM modules need to be included. --- Resend as I was not subscribed to the mailinglist. --- dracut-module-setup.sh | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/dracut-module-setup.sh b/dracut-module-setup.sh index 9f88b4e..8495fd9 100755 --- a/dracut-module-setup.sh +++ b/dracut-module-setup.sh @@ -20,7 +20,7 @@ check() { depends() { local _dep="base shutdown" - if [ -d /sys/module/drm/drivers ]; then + if [ -n "$( find /sys/devices -name drm )" ]; then _dep="$_dep drm" fi -- 2.9.3

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[PATCH] kdump.conf.5: clarify the fence_kdump_nodes option
by Pingfan Liu 08 Jun '17

08 Jun '17

fence_kdump_nodes should include list of cluster node(s) except localhost. Signed-off-by: Pingfan Liu <piliu(a)redhat.com> --- kdump.conf.5 | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kdump.conf.5 b/kdump.conf.5 index b581964..11b1fad 100644 --- a/kdump.conf.5 +++ b/kdump.conf.5 @@ -200,7 +200,7 @@ arguments except hosts to send notification to). .B fence_kdump_nodes <node(s)> .RS -List of cluster node(s), separated by spaces, to send fence_kdump notification +List of cluster node(s) except localhost, separated by spaces, to send fence_kdump notification to (this option is mandatory to enable fence_kdump). .RE -- 2.7.4

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[PATCH 0/2] Fix issues reported by rpmlint for kexec-tools
by Bhupesh Sharma 07 Jun '17

07 Jun '17

Resolves: BZ1433852 https://bugzilla.redhat.com/show_bug.cgi?id=1433852 This patchset fixes a couple of issues reported by rpmlint when it is run on kexec-tools: 1. Patch 1 fixes several instances of hardcoded-library-path errors. 2. Patch 2 fixes a couple of whitespace errors. Bhupesh Sharma (2): kexec-tools.spec: Fix hardcoded-library-path errors kexec-tools.spec: Fix whitespace errors kexec-tools.spec | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) -- 2.7.4

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[PATCH v2 0/3] Change kdump configuration file layout
by Bhupesh Sharma 05 Jun '17

05 Jun '17

This patchset addresses Fedora BZ1078311 and introduces a new configuration file layout structure for the kdump files. Changes since v1: ----------------- - Address review comments from Pratyush ~ Break the earlier single patch into simpler patches. ~ Other review comments. - Improve the kdump configuration file generation to do the same automatically when a new package is installed. Patchset Description: -------------------- Patch 1: Start using sensible MACROs for kdump config files across other helper scripts. Patch 2: Improves the description at the top of kdump.conf Patch 3: Patch which actually changes the kdump configuration file layout. Bhupesh Sharma (3): Use sensible MACROs for kdump config files across other helper scripts kdump.conf: Improve description Change kdump configuration file layout dracut-module-setup.sh | 10 +- fadump-howto.txt | 8 +- kdump-create-config.sh | 373 +++++++++++++++++++++++++++++++++++++++++++++ kdump-lib-initramfs.sh | 2 +- kdump-lib.sh | 21 +-- kdump.conf | 4 +- kdump.conf.5 | 43 +++++- kdumpctl | 31 ++-- kexec-kdump-howto.txt | 18 +-- kexec-tools.spec | 30 ++-- live-image-kdump-howto.txt | 2 +- mkdumprd | 4 +- mkdumprd.8 | 4 +- 13 files changed, 481 insertions(+), 69 deletions(-) create mode 100755 kdump-create-config.sh -- 2.7.4

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kdump will unconditionally to open LUKS device
by Benjamin Berg 24 May '17

24 May '17

Hi, I was trying to configure kernel dumping (on a Fedora 25 machine). In this case the installation is encrypted using LUKS so to make things work I decided to dump to /boot instead. Now, I do understand prompting for the LUKS password if the dump path is on an encrypted device (which mkdumprd helpfully warns about). But I don't see why dumping to e.g. an unencrypted partition like /boot instead (or through ssh) should even try to open any LUKS devices. There is no warning generated in that case but I still get a prompt for the password and dumping will only proceed afterwards. This seems odd. Mounting anything other than the dump location should not be necessary for the dumping processes. So the LUKS device should not be opened in this particular case. It should only happen if the user selected an encrypted volume as the dump target. Benjamin

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[PATCH v3] kdumpctl: for fence_kdump, the ipaddr of this node should be excluded from list
by Pingfan Liu 18 May '17

18 May '17

kdump should not send fence_kdump notifications to local host, because the role of the falied node (i.e local host) is to send fence_kdump notifications to other nodes to tell them I'm kdumping, tell to itself is nonsense. And we have excluded hostname of local host but when one use ip address we also need exclude it. Signed-off-by: Pingfan Liu <piliu(a)redhat.com> --- kdump.conf | 4 ++-- kdumpctl | 7 +++++++ 2 files changed, 9 insertions(+), 2 deletions(-) diff --git a/kdump.conf b/kdump.conf index 1e24e1b..cfdaec7 100644 --- a/kdump.conf +++ b/kdump.conf @@ -137,8 +137,8 @@ # # fence_kdump_nodes <node(s)> # - List of cluster node(s), separated by spaces, to send -# fence_kdump notifications to (this option is mandatory to -# enable fence_kdump). +# fence_kdump notifications to. The list should exclude this node itself! +# (this option is mandatory to enable fence_kdump). # #raw /dev/vg/lv_kdump diff --git a/kdumpctl b/kdumpctl index 60bbd93..e440bbb 100755 --- a/kdumpctl +++ b/kdumpctl @@ -1099,6 +1099,7 @@ check_kdump_feasibility() check_fence_kdump_config() { local hostname=`hostname` + local ipaddrs=`hostname -I` local nodes=$(get_option_value "fence_kdump_nodes") for node in $nodes; do @@ -1106,6 +1107,12 @@ check_fence_kdump_config() echo "Option fence_kdump_nodes cannot contain $hostname" return 1 fi + # node can be ipaddr + echo $ipaddrs | grep $node > /dev/null + if [ $? -eq 0 ]; then + echo "Option fence_kdump_nodes cannot contain $node" + return 1 + fi done return 0 -- 2.7.4

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[PATCH v2] kdumpctl: for fence_kdump, the ipaddr of this node should be excluded from list
by Pingfan Liu 16 May '17

16 May '17

In kdump.conf, the fence_kdump_nodes list can be hostname or ipaddr. We have already excluded the node's hostname from the list to avoid the deadlock issue in capture kernel. This patch applies the same rule on ipaddr. Signed-off-by: Pingfan Liu <piliu(a)redhat.com> --- v1 -> v2: improve commit log kdump.conf | 4 ++-- kdumpctl | 7 +++++++ 2 files changed, 9 insertions(+), 2 deletions(-) diff --git a/kdump.conf b/kdump.conf index 1e24e1b..cfdaec7 100644 --- a/kdump.conf +++ b/kdump.conf @@ -137,8 +137,8 @@ # # fence_kdump_nodes <node(s)> # - List of cluster node(s), separated by spaces, to send -# fence_kdump notifications to (this option is mandatory to -# enable fence_kdump). +# fence_kdump notifications to. The list should exclude this node itself! +# (this option is mandatory to enable fence_kdump). # #raw /dev/vg/lv_kdump diff --git a/kdumpctl b/kdumpctl index d43f46b..638c6b6 100755 --- a/kdumpctl +++ b/kdumpctl @@ -1118,6 +1118,7 @@ check_kdump_feasibility() check_fence_kdump_config() { local hostname=`hostname` + local ipaddrs=`hostname -i` local nodes=$(get_option_value "fence_kdump_nodes") for node in $nodes; do @@ -1125,6 +1126,12 @@ check_fence_kdump_config() echo "Option fence_kdump_nodes cannot contain $hostname" return 1 fi + # node can be ipaddr + echo $ipaddrs | grep $node + if [ $? -eq 0 ]; then + echo "Option fence_kdump_nodes cannot contain $node" + return 1 + fi done return 0 -- 2.7.4

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[PATCH] kdumpctl: change the shebang header to use /bin/bash
by Xunlei Pang 11 May '17

11 May '17

We met one issue that when changing softlink of "/usr/bin/sh" to point to "ksh" instead of the default "bash", kdumpctl will not work and go wrong. kdumpctl is expected to run under bash like dracut, we should change its shebang header from "#!/bin/sh" to "#!/bin/bash". Signed-off-by: Xunlei Pang <xlpang(a)redhat.com> --- kdumpctl | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kdumpctl b/kdumpctl index 4d6b3e8..d35c83a 100755 --- a/kdumpctl +++ b/kdumpctl @@ -1,4 +1,4 @@ -#! /bin/sh +#!/bin/bash KEXEC=/sbin/kexec KDUMP_KERNELVER="" -- 1.8.3.1

2 1

[PATCH 1/2] Revert "kdumpctl: improve "while read" time for /etc/kdump.conf"
by Xunlei Pang 11 May '17

11 May '17

Resolves: bz1449801 "cat $KDUMP_CONFIG_FILE|grep -v "^#"|while read ..." use pipes to invoke subshells, as a result we met "the dreaded inaccessible variables within a subshell problem" as described in the book "Advanced Bash-Scripting Guide". It cause regressions, so revert it. --- kdumpctl | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/kdumpctl b/kdumpctl index 46b65d2..644cf96 100755 --- a/kdumpctl +++ b/kdumpctl @@ -365,11 +365,11 @@ check_config() return 1 } - cat $KDUMP_CONFIG_FILE | grep -v "^#" | while read config_opt config_val; do + while read config_opt config_val; do # remove inline comments after the end of a directive. config_val=$(strip_comments $config_val) case "$config_opt" in - "") + \#* | "") ;; raw|ext2|ext3|ext4|minix|btrfs|xfs|nfs|ssh|sshkey|path|core_collector|kdump_post|kdump_pre|extra_bins|extra_modules|default|force_rebuild|force_no_rebuild|dracut_args|fence_kdump_args|fence_kdump_nodes) [ -z "$config_val" ] && { @@ -386,7 +386,7 @@ check_config() return 1; ;; esac - done + done < $KDUMP_CONFIG_FILE check_default_config || return 1 @@ -799,7 +799,7 @@ load_kdump() check_ssh_config() { - cat $KDUMP_CONFIG_FILE | grep -v "^#" | while read config_opt config_val; do + while read config_opt config_val; do # remove inline comments after the end of a directive. config_val=$(strip_comments $config_val) case "$config_opt" in @@ -820,7 +820,7 @@ check_ssh_config() *) ;; esac - done + done < $KDUMP_CONFIG_FILE #make sure they've configured kdump.conf for ssh dumps local SSH_TARGET=`echo -n $DUMP_TARGET | sed -n '/.*@/p'` -- 1.8.3.1

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kexec May 2017