kexec January 2023

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4 discussions

[PATCH] Install nfsv4-related drivers when users specify nfs dumping via dracut_args
by Coiby Xu 21 Mar '23

21 Mar '23

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=2140721 Currently, if users specify dumping to nfsv4 target via dracut_args --mount "<NFS-server-ip>:/var/crash /mnt nfs defaults" it fails with the following errors, [ 5.159760] mount[446]: mount.nfs: Protocol not supported [ 5.164502] systemd[1]: mnt.mount: Mount process exited, code=exited, status=32/n/a [ 5.167616] systemd[1]: mnt.mount: Failed with result 'exit-code'. [FAILED] Failed to mount /mnt. This is because nfsv4-releted drivers are not installed to kdump initrd. mkdumprd calls dracut with "--hostonly-mode strict". If nfsv4-related drivers aren't loaded before calling dracut, they won't be installed. When users specify nfs dumping via dracut_args, kexec-tools won't mount the nfs fs beforehand hence nfsv4-related drivers won't be installed. Note dracut only installs the nfs driver i.e. nfsv3 driver for "--mount ... nfs". So also install nfsv4-related drivers when users specify nfs dumping via dracut_args. Since nfs_layout_nfsv41_files depends on nfsv4, the nfsv4 driver will be installed automatically. As for the reason why we support nfs dumping via dracut_args instead of asking user to use the nfs directive, please refer to commit 74c6f464 ("Support special mount information via 'dracut_args'"). Fixes: 4eedcae5 ("dracut-module-setup.sh: don't include multipath-hostonly") Reported-by: rcheerla(a)redhat.com Signed-off-by: Coiby Xu <coxu(a)redhat.com> --- mkdumprd | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/mkdumprd b/mkdumprd index 3e250e02..51ca4f01 100644 --- a/mkdumprd +++ b/mkdumprd @@ -420,6 +420,15 @@ while read -r config_opt config_val; do verify_core_collector "$config_val" ;; dracut_args) + + # When users specify nfs dumping via dracut_args, kexec-tools won't + # mount nfs fs beforehand thus nfsv4-related drivers won't be installed + # because we call dracut with --hostonly-mode strict. So manually install + # nfsv4-related drivers. + if [[ $(get_dracut_args_fstype "$config_val") == nfs* ]]; then + add_dracut_arg "--add-drivers" nfs_layout_nfsv41_files + fi + while read -r dracut_arg; do add_dracut_arg "$dracut_arg" done <<< "$(echo "$config_val" | xargs -n 1 echo)" -- 2.38.1

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[PATCH v2 00/13] various fixes and cleanups
by Philipp Rudo 30 Jan '23

30 Jan '23

Hi everybody, here are a few patches before I go on Christmas vacation. I'll be back in office on Jan 9th so you don't need to hurry to review them. Patch 3 is a little bit special as in my opinion it only highlights the problem but doesn't really fix it. For a proper fix one would need to move all functions dracut-early-kdump.sh uses from kdump-lib to kdump-lib-initramfs and make them POSIX compliant... Thanks and see you next year Philipp --- v1->v2: * incorporate Coibys comments, i.e. disable shellcheck in patch 2 rather than quoting EARLY_KEXEC_ARGS and move image_time to check_files_modified and make it local in patch 13. Philipp Rudo (13): kdumpctl: simplify check_failure_action_config dracut-early-kdump: fix shellcheck findings dracut-early-kdump: explicitly use bash kdumpctl: merge check_current_{kdump,fadump}_status mkfadumprd: drop unset globals from debug output kdump-lib: always specify version in is_squash_available unit tests: add tests for prepare_cmdline kdumpctl: move aws workaround to kdump-lib kdump-lib: fix prepare_cmdline kdumpctl: cleanup 'start' kdumpctl: cleanup 'stop' kdumpctl: refractor check_rebuild kdumpctl: make do_estimate more robust .editorconfig | 2 +- dracut-early-kdump.sh | 6 +- kdump-lib.sh | 226 +++++++++++++++++-------------- kdumpctl | 296 +++++++++++++++-------------------------- mkfadumprd | 2 +- spec/kdump-lib_spec.sh | 32 +++++ 6 files changed, 272 insertions(+), 292 deletions(-) mode change 100644 => 100755 mkfadumprd -- 2.39.0

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[PATCH] makedumpfile: Fix wrong exclusion of slab pages on Linux 6.2-rc1
by Coiby Xu 30 Jan '23

30 Jan '23

Resolves: bz2155754 Upstream: https://github.com/makedumpfile/makedumpfile Conflict: None commit 5f17bdd2128998a3eeeb4521d136a192222fadb6 Author: Kazuhito Hagio <k-hagio-ab(a)nec.com> Date: Wed Dec 21 11:06:39 2022 +0900 [PATCH] Fix wrong exclusion of slab pages on Linux 6.2-rc1 * Required for kernel 6.2 Kernel commit 130d4df57390 ("mm/sl[au]b: rearrange struct slab fields to allow larger rcu_head"), which is contained in Linux 6.2-rc1 and later, made the offset of slab.slabs equal to page.mapping's one. As a result, "makedumpfile -d 8", which should exclude user data, excludes some slab pages wrongly because isAnon() returns true when slab.slabs is an odd number. With such dumpfiles, crash can fail to start session with an error like this: # crash vmlinux dumpfile ... crash: page excluded: kernel virtual address: ffff8fa047ac2fe8 type: "xa_node shift" Make isAnon() check that the page is not slab to fix this. Signed-off-by: Kazuhito Hagio <k-hagio-ab(a)nec.com> Reported-by: Baoquan He <bhe(a)redhat.com> Signed-off-by: Coiby Xu <coxu(a)redhat.com> --- ...exclusion-of-slab-pages-on-Linux-6.2.patch | 81 +++++++++++++++++++ kexec-tools.spec | 2 + 2 files changed, 83 insertions(+) create mode 100644 kexec-tools-2.0.26-makedumpfile-Fix-wrong-exclusion-of-slab-pages-on-Linux-6.2.patch diff --git a/kexec-tools-2.0.26-makedumpfile-Fix-wrong-exclusion-of-slab-pages-on-Linux-6.2.patch b/kexec-tools-2.0.26-makedumpfile-Fix-wrong-exclusion-of-slab-pages-on-Linux-6.2.patch new file mode 100644 index 00000000..5d91bc21 --- /dev/null +++ b/kexec-tools-2.0.26-makedumpfile-Fix-wrong-exclusion-of-slab-pages-on-Linux-6.2.patch @@ -0,0 +1,81 @@ +From 5f17bdd2128998a3eeeb4521d136a192222fadb6 Mon Sep 17 00:00:00 2001 +From: Kazuhito Hagio <k-hagio-ab(a)nec.com> +Date: Wed, 21 Dec 2022 11:06:39 +0900 +Subject: [PATCH] [PATCH] Fix wrong exclusion of slab pages on Linux 6.2-rc1 + +* Required for kernel 6.2 + +Kernel commit 130d4df57390 ("mm/sl[au]b: rearrange struct slab fields to +allow larger rcu_head"), which is contained in Linux 6.2-rc1 and later, +made the offset of slab.slabs equal to page.mapping's one. As a result, +"makedumpfile -d 8", which should exclude user data, excludes some slab +pages wrongly because isAnon() returns true when slab.slabs is an odd +number. With such dumpfiles, crash can fail to start session with an +error like this: + + # crash vmlinux dumpfile + ... + crash: page excluded: kernel virtual address: ffff8fa047ac2fe8 type: "xa_node shift" + +Make isAnon() check that the page is not slab to fix this. + +Signed-off-by: Kazuhito Hagio <k-hagio-ab(a)nec.com> +--- + makedumpfile.c | 6 +++--- + makedumpfile.h | 9 +++------ + 2 files changed, 6 insertions(+), 9 deletions(-) + +diff --git a/makedumpfile-1.7.2/makedumpfile.c b/makedumpfile-1.7.2/makedumpfile.c +index ff821eb..f403683 100644 +--- a/makedumpfile-1.7.2/makedumpfile.c ++++ b/makedumpfile-1.7.2/makedumpfile.c +@@ -6502,7 +6502,7 @@ __exclude_unnecessary_pages(unsigned long mem_map, + */ + else if ((info->dump_level & DL_EXCLUDE_CACHE) + && is_cache_page(flags) +- && !isPrivate(flags) && !isAnon(mapping)) { ++ && !isPrivate(flags) && !isAnon(mapping, flags)) { + pfn_counter = &pfn_cache; + } + /* +@@ -6510,7 +6510,7 @@ __exclude_unnecessary_pages(unsigned long mem_map, + */ + else if ((info->dump_level & DL_EXCLUDE_CACHE_PRI) + && is_cache_page(flags) +- && !isAnon(mapping)) { ++ && !isAnon(mapping, flags)) { + if (isPrivate(flags)) + pfn_counter = &pfn_cache_private; + else +@@ -6522,7 +6522,7 @@ __exclude_unnecessary_pages(unsigned long mem_map, + * - hugetlbfs pages + */ + else if ((info->dump_level & DL_EXCLUDE_USER_DATA) +- && (isAnon(mapping) || isHugetlb(compound_dtor))) { ++ && (isAnon(mapping, flags) || isHugetlb(compound_dtor))) { + pfn_counter = &pfn_user; + } + /* +diff --git a/makedumpfile-1.7.2/makedumpfile.h b/makedumpfile-1.7.2/makedumpfile.h +index 70a1a91..21dec7d 100644 +--- a/makedumpfile-1.7.2/makedumpfile.h ++++ b/makedumpfile-1.7.2/makedumpfile.h +@@ -161,12 +161,9 @@ test_bit(int nr, unsigned long addr) + #define isSwapBacked(flags) test_bit(NUMBER(PG_swapbacked), flags) + #define isHWPOISON(flags) (test_bit(NUMBER(PG_hwpoison), flags) \ + && (NUMBER(PG_hwpoison) != NOT_FOUND_NUMBER)) +- +-static inline int +-isAnon(unsigned long mapping) +-{ +- return ((unsigned long)mapping & PAGE_MAPPING_ANON) != 0; +-} ++#define isSlab(flags) test_bit(NUMBER(PG_slab), flags) ++#define isAnon(mapping, flags) (((unsigned long)mapping & PAGE_MAPPING_ANON) != 0 \ ++ && !isSlab(flags)) + + #define PTOB(X) (((unsigned long long)(X)) << PAGESHIFT()) + #define BTOP(X) (((unsigned long long)(X)) >> PAGESHIFT()) +-- +2.39.0 + diff --git a/kexec-tools.spec b/kexec-tools.spec index ea49eb2c..33656dc4 100644 --- a/kexec-tools.spec +++ b/kexec-tools.spec @@ -105,6 +105,7 @@ Requires: systemd-udev%{?_isa} # # Patches 601 onward are generic patches # +Patch601: kexec-tools-2.0.26-makedumpfile-Fix-wrong-exclusion-of-slab-pages-on-Linux-6.2.patch %description kexec-tools provides /sbin/kexec binary that facilitates a new @@ -120,6 +121,7 @@ mkdir -p -m755 kcp tar -z -x -v -f %{SOURCE9} tar -z -x -v -f %{SOURCE19} +%patch601 -p1 %ifarch ppc %define archdef ARCH=ppc -- 2.39.0

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[PATCH 00/13] various fixes and cleanups
by Philipp Rudo 12 Jan '23

12 Jan '23

Hi everybody, here are a few patches before I go on Christmas vacation. I'll be back in office on Jan 9th so you don't need to hurry to review them. Patch 3 is a little bit special as in my opinion it only highlights the problem but doesn't really fix it. For a proper fix one would need to move all functions dracut-early-kdump.sh uses from kdump-lib to kdump-lib-initramfs and make them POSIX compliant... Thanks and see you next year Philipp Philipp Rudo (13): kdumpctl: simplify check_failure_action_config dracut-early-kdump: fix shellcheck findings dracut-early-kdump: explicitly use bash kdumpctl: merge check_current_{kdump,fadump}_status mkfadumprd: drop unset globals from debug output kdump-lib: always specify version in is_squash_available unit tests: add tests for prepare_cmdline kdumpctl: move aws workaround to kdump-lib kdump-lib: fix prepare_cmdline kdumpctl: cleanup 'start' kdumpctl: cleanup 'stop' kdumpctl: refractor check_rebuild kdumpctl: make do_estimate more robust .editorconfig | 2 +- dracut-early-kdump.sh | 7 +- kdump-lib.sh | 226 +++++++++++++++++--------------- kdumpctl | 287 +++++++++++++++-------------------------- mkfadumprd | 2 +- spec/kdump-lib_spec.sh | 32 +++++ 6 files changed, 266 insertions(+), 290 deletions(-) mode change 100644 => 100755 mkfadumprd -- 2.38.1

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kexec January 2023