kexec December 2021

kexec@lists.fedoraproject.org

7 participants
17 discussions

[PATCH v3 00/13] crashkernel=auto: support fadump and remove crashkernel.default
by Coiby Xu 23 Dec '21

23 Dec '21

v3: - fixes suggested by Philipp - fix incorrect usage of kdump_get_arch_recommend_crashkernel - s/get_default_crashkernel/get-default-crashkernel - no longer depends on grubby --update-kernel=ALL to update all kernels' command line parameter and using a single loop to simplify the code - indentation issue fix - commit message improvement - update crashkernel-howto.txt as suggested by Dave - CoreOS suppport - makes "kdumpctl reset-crashkernel" work for CoreOS - kdumpctl can't be run in RPM scriplet, disable it for CoreOS - set up kernel crashkernel for osbuild v2: - no longer address the swiotlb memory requirement when SME is enabled - automatically reset crashkernel to default value only when the value is set by kexec-tools before. So the crashkernel option to added to kdump.conf is replaced auto_reset_crashkernel option instead - multiple fixes suggested by Philipp including regex improvement, typo fixes, grubby kernel path check and commit message improvements - address the case where a kernel path is not /boot/vmlinuz-{KERNEL_RELEASE} - "kdumpctl fadump" dropped. Support fadump via "kdumpctl reset-crashkernel [--fadump=[on|off|nocma]]" instead The crashkernel=auto implementation in kernel space has been rejected upstream [1]. The current user space implementation [2] [3] ships a crashkernel.default but hasn't supported fadump. Meanwhile the crashkernel.default implementation seems to be overly complex, - the default kernel crashkernel value rarely changes. This is no need to ship the same crashkernel.default default for every kernel package of a architecture; - when deciding the value of crashkernel for a new kernel, the crashkernel.default of installed kernels and running kernel is took into consideration (for the details, check 92-crashnernel.install). According to Kairui [4], crashkernel.default per kernel package is to accommodate kernel difference, for example, different kernels could be built with different configurations thus different crashkernel values are needed. But these should be minor cases and may not be sufficent to justify the complexity of 92-crashkernel.install. Currently, we don't know how a kernel debug/feature config would affect the crashkernel value. Even if a kernel config may require much larger crashkernel, we can address it in kexec-tools later. There are are known cases that could lead to a larger crashkernel including enabling SME, LUKS encryption and etc. But this patch set would put them aside since they may be took care of in the kernel space instead. So this patch set would simply add support for fadump and move the default kernel crashkernel from kernel package to kexec-tools, - provide "kdumpctl get-default-crashkernel" for kdump-anaconda-addon to get the default kernel crashkernel values for a specific architecture (fadump is supported as well) - re-write "kdumpctl reset-crashkernel" to support fadump - introduce auto_reset_crashkernel which determines whether to reset kernel crashkernel to new default value or not when kexec-tools updates the default crashkernel value Because the kernel hook /usr/lib/kernel/install.d/20-grub.install would make the installed kernel inherit the kernel cmdline of current running kernel i.e. /proc/cmdline, we only need to reset crashkernel when kexec-tools increases the default crashkernel values. [1] https://lore.kernel.org/linux-mm/20210507010432.IN24PudKT%25akpm@linux-foun… [2] https://gitlab.com/cki-project/kernel-ark/-/merge_requests/1171 [3] https://lists.fedoraproject.org/archives/list/kexec@lists.fedoraproject.org… [4] https://lists.fedoraproject.org/archives/list/kexec@lists.fedoraproject.org… Coiby Xu (13): update default crashkernel value factor out kdump_get_arch_recommend_crashkernel provide kdumpctl get-default-crashkernel for kdump_anaconda_addon and RPM scriptlet add a helper function to read kernel cmdline parameter from grubby --info add helper functions to get dump mode add helper functions to get kernel path by kernel release and the path of current running kernel fix incorrect usage of rpm-ostree to update kernel command line parameters rewrite reset_crashkernel to support fadump and to used by RPM scriptlet introduce the auto_reset_crashkernel option to kdump.conf try to reset kernel crashkernel when kexec-tools updates the default crashkernel value reset kernel crashkernel for the special case where the kernel is updated right after kexec-tools set up kernel crashkernel for osbuild in kernel hook update crashkernel-howto 92-crashkernel.install | 135 +---------------- crashkernel-howto.txt | 123 +++------------- kdump-lib.sh | 60 ++++---- kdump.conf | 7 + kdump.conf.5 | 6 + kdumpctl | 320 ++++++++++++++++++++++++++++++++++++++--- kdumpctl.8 | 16 ++- kexec-tools.spec | 15 ++ 8 files changed, 393 insertions(+), 289 deletions(-) -- 2.31.1

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[PATCHv2] ppc64/ppc64le: drop cpu online rule in 40-redhat.rules in kdump initramfs
by Pingfan Liu 23 Dec '21

23 Dec '21

Onlining secondary cpus breaks kdump completely on KVM on Power hosts Though we use maxcpus=1 by default but 40-redhat.rules will bring up all possible cpus by default. Thus before we get the kernel fix and the systemd rule fix let's remove the cpu rule in 40-redhat.rules for ppc64/ppc64le kdump initramfs. This is back ported from RHEL, and original credit goes to Dave Young <dyoung(a)redhat.com> Signed-off-by: Pingfan Liu <piliu(a)redhat.com> --- dracut-module-setup.sh | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/dracut-module-setup.sh b/dracut-module-setup.sh index 1ea0d95..c319fc2 100755 --- a/dracut-module-setup.sh +++ b/dracut-module-setup.sh @@ -1010,11 +1010,29 @@ kdump_install_systemd_conf() { echo "ForwardToConsole=yes" >> "${initdir}/etc/systemd/journald.conf.d/kdump.conf" } +remove_cpu_online_rule() { + local file=${initdir}/usr/lib/udev/rules.d/40-redhat.rules + + sed -i '/SUBSYSTEM=="cpu"/d' "$file" +} + install() { + local arch + kdump_module_init kdump_install_conf remove_sysctl_conf + # Onlining secondary cpus breaks kdump completely on KVM on Power hosts + # Though we use maxcpus=1 by default but 40-redhat.rules will bring up all + # possible cpus by default. (rhbz1270174 rhbz1266322) + # Thus before we get the kernel fix and the systemd rule fix let's remove + # the cpu online rule in kdump initramfs. + arch=$(uname -m) + if [[ "$arch" = "ppc64le" ]] || [[ "$arch" = "ppc64" ]]; then + remove_cpu_online_rule + fi + if is_ssh_dump_target; then kdump_install_random_seed fi -- 2.31.1

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[PATCH] Set zstd as the default compression method for kdump initrd
by Tao Liu 20 Dec '21

20 Dec '21

zstd has better compression ratio and time consumption balance than zlib/lzo/snappy. When no customized compression method is specified in kdump.conf, we will use zstd as the default compression method for initrd. Signed-off-by: Tao Liu <ltao(a)redhat.com> --- kdump-lib.sh | 7 +++++++ mkdumprd | 4 ++++ mkfadumprd | 4 ++++ 3 files changed, 15 insertions(+) diff --git a/kdump-lib.sh b/kdump-lib.sh index e435498..82c2616 100755 --- a/kdump-lib.sh +++ b/kdump-lib.sh @@ -443,6 +443,13 @@ is_wdt_active() return 1 } +have_compression_in_dracut_args() +{ + grep -q "^dracut_args .*\-\- + $gzip\|bzip2\|lzma\|xz\|lzo\|lz4\|zstd\|compress\|no-compress$ + $[[:space:]]\|$$" /etc/kdump.conf +} + # If "dracut_args" contains "--mount" information, use it # directly without any check(users are expected to ensure # its correctness). diff --git a/mkdumprd b/mkdumprd index d87d588..9c26ecc 100644 --- a/mkdumprd +++ b/mkdumprd @@ -431,6 +431,10 @@ done <<< "$(kdump_read_conf)" handle_default_dump_target +if ! have_compression_in_dracut_args; then + add_dracut_arg "--compress" "zstd" +fi + if [[ -n $extra_modules ]]; then add_dracut_arg "--add-drivers" "$extra_modules" fi diff --git a/mkfadumprd b/mkfadumprd index b890f83..16fdacc 100644 --- a/mkfadumprd +++ b/mkfadumprd @@ -62,6 +62,10 @@ if is_squash_available; then _dracut_isolate_args+=(--add squash) fi +if ! have_compression_in_dracut_args; then + _dracut_isolate_args+=(--compress zstd) +fi + if ! dracut --force --quiet "${_dracut_isolate_args[@]}" "$@" "$TARGET_INITRD"; then perror_exit "mkfadumprd: failed to setup '$TARGET_INITRD' with dump capture capability" fi -- 2.33.1

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[PATCH] ppc64/ppc64le: drop cpu online rule in 40-redhat.rules in kdump initramfs
by Pingfan Liu 16 Dec '21

16 Dec '21

Onlining secondary cpus breaks kdump completely on KVM on Power hosts Though we use maxcpus=1 by default but 40-redhat.rules will bring up all possible cpus by default. Thus before we get the kernel fix and the systemd rule fix let's remove the cpu rule in 40-redhat.rules for ppc64/ppc64le kdump initramfs. This is back ported from RHEL, and original credit goes to Dave Young <dyoung(a)redhat.com> Signed-off-by: Pingfan Liu <piliu(a)redhat.com> --- dracut-module-setup.sh | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/dracut-module-setup.sh b/dracut-module-setup.sh index 1ea0d95..2c7b728 100755 --- a/dracut-module-setup.sh +++ b/dracut-module-setup.sh @@ -1010,11 +1010,29 @@ kdump_install_systemd_conf() { echo "ForwardToConsole=yes" >> "${initdir}/etc/systemd/journald.conf.d/kdump.conf" } +remove_cpu_online_rule() { + local file=${initdir}/usr/lib/udev/rules.d/40-redhat.rules + + sed -i '/SUBSYSTEM=="cpu"/d' $file +} + install() { + local arch + kdump_module_init kdump_install_conf remove_sysctl_conf + # Onlining secondary cpus breaks kdump completely on KVM on Power hosts + # Though we use maxcpus=1 by default but 40-redhat.rules will bring up all + # possible cpus by default. (rhbz1270174 rhbz1266322) + # Thus before we get the kernel fix and the systemd rule fix let's remove + # the cpu online rule in kdump initramfs. + arch=$(uname -m) + if [[ "$arch" = "ppc64le" ]] || [[ "$arch" = "ppc64" ]]; then + remove_cpu_online_rule + fi + if is_ssh_dump_target; then kdump_install_random_seed fi -- 2.31.1

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[PATCH] kdump-lib.sh: Escape '|' for "failure_action|default" in is_dump_to_rootfs
by Tao Liu 16 Dec '21

16 Dec '21

The '|' in "failure_action|default" should be escaped when passed to kdump_get_conf_val function. Otherwise the regex in kdump_get_conf_val will consider "failure_action|default" as a whole string instead of OR operation for 2 strings. Fixes: (commit ab1ef78aa25b7ae2e34e16a74712079653981e6b) kdump-lib.sh: use kdump_get_conf_val to read config values Signed-off-by: Tao Liu <ltao(a)redhat.com> --- kdump-lib.sh | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kdump-lib.sh b/kdump-lib.sh index d7d28ee..e435498 100755 --- a/kdump-lib.sh +++ b/kdump-lib.sh @@ -108,7 +108,7 @@ get_block_dump_target() is_dump_to_rootfs() { - [[ $(kdump_get_conf_val "failure_action|default") == dump_to_rootfs ]] + [[ $(kdump_get_conf_val "failure_action\|default") == dump_to_rootfs ]] } get_failure_action_target() -- 2.33.1

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[PATCH v2 00/10] crashkernel=auto: support fadump and remove crashkernel.default
by Coiby Xu 16 Dec '21

16 Dec '21

v2: - no longer address the swiotlb memory requirement when SME is enabled - automatically reset crashkernel to default value only when the value is set by kexec-tools before. So the crashkernel option to added to kdump.conf is replaced auto_reset_crashkernel option instead - multiple fixes suggested by Philipp including regex improvement, typo fixes, grubby kernel path check and commit message improvements - address the case where a kernel path is not /boot/vmlinuz-{KERNEL_RELEASE} - "kdumpctl fadump" dropped. Support fadump via "kdumpctl reset-crashkernel [--fadump=[on|off|nocma]]" instead The crashkernel=auto implementation in kernel space has been rejected upstream [1]. The current user space implementation [2] [3] ships a crashkernel.default but hasn't supported fadump. Meanwhile the crashkernel.default implementation seems to be overly complex, - the default kernel crashkernel value rarely changes. This is no need to ship the same crashkernel.default default for every kernel package of a architecture; - when deciding the value of crashkernel for a new kernel, the crashkernel.default of installed kernels and running kernel is took into consideration (for the details, check 92-crashnernel.install). According to Kairui [4], crashkernel.default per kernel package is to accommodate kernel difference, for example, different kernels could be built with different configurations thus different crashkernel values are needed. But these should be minor cases and may not be sufficent to justify the complexity of 92-crashkernel.install. Currently, we don't know how a kernel debug/feature config would affect the crashkernel value. Even if a kernel config may require much larger crashkernel, we can address it in kexec-tools later. There are are known cases that could lead to a larger crashkernel including enabling SME, LUKS encryption and etc. But this patch set would put them aside since they may be took care of in the kernel space instead. So this patch set would simply add support for fadump and move the default kernel crashkernel from kernel package to kexec-tools, - provide "kdumpctl get-default-crashkernel" for kdump-anaconda-addon to get the default kernel crashkernel values for a specific architecture (fadump is supported as well) - re-write "kdumpctl reset-crashkernel" to support fadump - introduce auto_reset_crashkernel which determines whether to reset kernel crashkernel to new default value or not when kexec-tools updates the default crashkernel value Because the kernel hook /usr/lib/kernel/install.d/20-grub.install would make the installed kernel inherit the kernel cmdline of current running kernel i.e. /proc/cmdline, we only need to reset crashkernel when kexec-tools increases the default crashkernel values. [1] https://lore.kernel.org/linux-mm/20210507010432.IN24PudKT%25akpm@linux-foun… [2] https://gitlab.com/cki-project/kernel-ark/-/merge_requests/1171 [3] https://lists.fedoraproject.org/archives/list/kexec@lists.fedoraproject.org… [4] https://lists.fedoraproject.org/archives/list/kexec@lists.fedoraproject.org… Coiby Xu (10): update default crashkernel value factor out kdump_get_arch_recommend_crashkernel provide kdumpctl get-default-crashkernel for kdump_anaconda_addon and RPM scriptlet add a helper function to read kernel cmdline parameter from grubby --info add helper functions to get dump mode add helper functions to get kernel path by kernel release and the path of current running kernel rewrite reset_crashkernel to support fadump and to used by RPM scriptlet introduce the auto_reset_crashkernel option to kdump.conf try to reset kernel crashkernel when kexec-tools updates the default crashkernel value reset kernel crashkernel for the special case where the kernel is updated right after kexec-tools 92-crashkernel.install | 135 +--------------------- kdump-lib.sh | 60 ++++++---- kdump.conf | 7 ++ kdump.conf.5 | 6 + kdumpctl | 256 +++++++++++++++++++++++++++++++++++++---- kexec-tools.spec | 15 +++ 6 files changed, 301 insertions(+), 178 deletions(-) -- 2.31.1

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[PATCH] kdump/ppc64: suppress the error message "Could not find a registered notification tool" from servicelog_notify
by Coiby Xu 02 Dec '21

02 Dec '21

When kexec-tools is newly installed, kdump migration action isn't registered and the following error could occur, INF dnf.rpm: Could not find a registered notification tool with the specified command ('/usr/lib/kdump/kdump-migrate-action.sh'). "servicelog_notify --list" could list registered notification tools for a command but it outputs the above error as well. So simply redirect the error to /dev/null when running "servicelog_notify --remove". Fixes: commit 146f66262222e96bca47b691ed243fa5097aa55c ("kdump/ppc64: migration action registration clean up") Signed-off-by: Coiby Xu <coxu(a)redhat.com> --- kexec-tools.spec | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kexec-tools.spec b/kexec-tools.spec index dcab391..ab7f41f 100644 --- a/kexec-tools.spec +++ b/kexec-tools.spec @@ -265,7 +265,7 @@ mv $RPM_BUILD_ROOT/etc/kdump-adv-conf/kdump_dracut_modules/* $RPM_BUILD_ROOT/%{d touch /etc/kdump.conf %ifarch ppc64 ppc64le -servicelog_notify --remove --command=/usr/lib/kdump/kdump-migrate-action.sh +servicelog_notify --remove --command=/usr/lib/kdump/kdump-migrate-action.sh 2>/dev/null servicelog_notify --add --command=/usr/lib/kdump/kdump-migrate-action.sh --match='refcode="#MIGRATE" and serviceable=0' --type=EVENT --method=pairs_stdin %endif -- 2.31.1

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