[Crash-utility] Re: [PATCH v2] sys: Display livepatch transition status in KERNEL line

-----Original Message----- From: Tao Liu <ltao(a)redhat.com&gt; Sent: Thursday, February 12, 2026 9:01 PM To: Qi, Fuli/斉 福利 <qi.fuli(a)fujitsu.com&gt; Cc: Motomasa Suzuki <moto0123moto(a)gmail.com>; devel(a)lists.crash-utility.osci.io Subject: Re: [PATCH v2] sys: Display livepatch transition status in KERNEL line [You don't often get email from ltao(a)redhat.com. Learn why this is important at https://aka.ms/LearnAboutSenderIdentification ] applied: https://github.com/crash-utility/crash/commit/24b5405eb6f67a96e8b5bbd5c 8de8f22dfefd092 On Thu, Feb 12, 2026 at 7:40 PM Tao Liu <ltao(a)redhat.com&gt; wrote: > > Hi Fuli, > > On Thu, Feb 12, 2026 at 6:57 PM Fuli Qi (Fujitsu) <qi.fuli(a)fujitsu.com&gt; wrote: > > > > Hello Tao Liu, > > > > Thank you for the review. > > Could you please kindly proceed with merging this patch? > > Sure, I will merge it today, sorry for the delay. > > Thanks, > Tao Liu > > > > Best, > > Fuli > > > > > -----Original Message----- > > > From: Tao Liu <ltao(a)redhat.com&gt; > > > Sent: Tuesday, December 30, 2025 1:32 PM > > > To: Motomasa Suzuki <moto0123moto(a)gmail.com&gt; > > > Cc: devel(a)lists.crash-utility.osci.io; Qi, Fuli/斉 福利 > > > <qi.fuli(a)fujitsu.com&gt; > > > Subject: Re: [PATCH v2] sys: Display livepatch transition status > > > in KERNEL line > > > > > > [You don't often get email from ltao(a)redhat.com. Learn why this is > > > important at https://aka.ms/LearnAboutSenderIdentification ] > > > > > > On Tue, Dec 23, 2025 at 6:51 PM Motomasa Suzuki > > > <moto0123moto(a)gmail.com&gt; wrote: > > > > > > > > This commit enhances the 'sys' command to show if a kernel > > > > livepatch is currently in a transition phase, directly within the KERNEL output line. > > > > > > > > Currently, diagnosing system state during or immediately after > > > > livepatch operations can be ambiguous. While 'livepatch' is > > > > indicated by '[LIVEPATCH]', there's no direct indicator within > > > > 'crash' itself to show if a livepatch is actively applying, > > > > reverting, or in some other transient state. This lack of > > > > immediate visibility can complicate crash analysis, as the > > > > system might be in an inconsistent state due to an ongoing patch application/reversion. > > > > > > > > This change introduces a new '[TRANSITION]' flag which appears > > > > next to '[LIVEPATCH]' and '[TAINTED]' in the 'sys' command > > > > output. This flag is set if the livepatch subsystem indicates an > > > > in-progress transition (e.g., as exposed via '/sys/kernel/livepatch/<patch_name>/transition'). > > > > > > > > Example 'sys' output with this change: > > > > KERNEL: /usr/lib/debug/lib/modules/<version_name>/vmlinux > > > > [LIVEPATCH] [TRANSITION] [TAINTED] > > > > > > > > This enhancement provides critical, at-a-glance information for > > > > developers and administrators, allowing them to quickly > > > > ascertain if ongoing livepatch activity might be influencing a > > > > system's behavior during crash investigations. It directly > > > > leverages existing kernel livepatch status infrastructure to > > > > enrich the crash utility's diagnostic capabilities. > > > > > > > > > > > > Changes v1 -> v2: > > > > - Reworked klp_patches list traversal to use the crash utility’s > > > > do_list() helper instead of manual list handling. > > > > > > The v2 LGTM, so ack. > > > > > > Thanks, > > > Tao Liu > > > > > > > > Signed-off-by: Motomasa Suzuki <moto0123moto(a)gmail.com&gt; > > > > --- > > > > defs.h | 1 + > > > > kernel.c | 75 > > > > > > > ++++++++++++++++++++++++++++++++++++++++++++++++ +++ > > > +++-- > > > > 2 files changed, 74 insertions(+), 2 deletions(-) > > > > > > > > diff --git a/defs.h b/defs.h > > > > index ceed3a9..cfdfa08 100644 > > > > --- a/defs.h > > > > +++ b/defs.h > > > > @@ -2289,6 +2289,7 @@ struct offset_table { /* stash of > > > commonly-used offsets */ > > > > long bpf_ringbuf_consumer_pos; > > > > long bpf_ringbuf_nr_pages; > > > > long hrtimer_clock_base_index; > > > > + long klp_patch_list; > > > > }; > > > > > > > > struct size_table { /* stash of commonly-used sizes */ > > > > diff --git a/kernel.c b/kernel.c index bb148d0..ccc4b3d 100644 > > > > --- a/kernel.c > > > > +++ b/kernel.c > > > > @@ -464,6 +464,11 @@ kernel_init() > > > > "list_head.next offset: %ld: list command may fail\n", > > > > OFFSET(list_head_next)); > > > > > > > > + if (STRUCT_EXISTS("klp_patch")) { > > > > + if (MEMBER_EXISTS("klp_patch", "list")) > > > > + MEMBER_OFFSET_INIT(klp_patch_list, > > > > + "klp_patch", > > > "list"); > > > > + } > > > > + > > > > MEMBER_OFFSET_INIT(hlist_node_next, "hlist_node", "next"); > > > > MEMBER_OFFSET_INIT(hlist_node_pprev, "hlist_node", "pprev"); > > > > STRUCT_SIZE_INIT(hlist_head, "hlist_head"); @@ -5689,6 > > > > +5694,70 @@ is_livepatch(void) > > > > return FALSE; > > > > } > > > > > > > > +struct klp_transition_ctx { > > > > + ulong transition_patch; > > > > + int found; > > > > +}; > > > > + > > > > +static int > > > > +klp_transition_match(void *entry, void *data) { > > > > + struct klp_transition_ctx *ctx = data; > > > > + > > > > + if ((ulong)entry == ctx->transition_patch) { > > > > + ctx->found = TRUE; > > > > + return TRUE; > > > > + } > > > > + > > > > + return FALSE; > > > > +} > > > > + > > > > +static int > > > > +is_livepatch_transition(void) > > > > +{ > > > > + struct kernel_list_head head; > > > > + struct list_data ld; > > > > + struct klp_transition_ctx ctx; > > > > + ulong transition_patch; > > > > + ulong list_addr; > > > > + int ret; > > > > + > > > > + if (!try_get_symbol_data("klp_transition_patch", > > > > + sizeof(ulong), &transition_patch) || !transition_patch) > > > > + return FALSE; > > > > + > > > > + if (!STRUCT_EXISTS("klp_patch") > > > || !VALID_MEMBER(klp_patch_list) || > > > > + !kernel_symbol_exists("klp_patches")) > > > > + return TRUE; > > > > + > > > > + list_addr = symbol_value("klp_patches"); > > > > + if (!readmem(list_addr, KVADDR, &head, sizeof(head), "klp_patches", > > > > + RETURN_ON_ERROR | QUIET)) > > > > + return TRUE; > > > > + > > > > + if (!head.next || head.next == (void *)list_addr) > > > > + return TRUE; > > > > + > > > > + BZERO(&ctx, sizeof(ctx)); > > > > + ctx.transition_patch = transition_patch; > > > > + > > > > + BZERO(&ld, sizeof(ld)); > > > > + ld.flags = > > > LIST_CALLBACK|CALLBACK_RETURN|RETURN_ON_LIST_ERROR| > > > > + RETURN_ON_DUPLICATE|LIST_ALLOCATE; > > > > + ld.start = (ulong)head.next; > > > > + ld.end = list_addr; > > > > + ld.member_offset = OFFSET(list_head_next); > > > > + ld.list_head_offset = OFFSET(klp_patch_list); > > > > + ld.callback_func = klp_transition_match; > > > > + ld.callback_data = &ctx; > > > > + > > > > + ret = do_list(&ld); > > > > + if (ret < 0) > > > > + return FALSE; > > > > + > > > > + return ctx.found; > > > > +} > > > > + > > > > /* > > > > * Display system stats at init-time or for the sys command. > > > > */ > > > > @@ -5732,17 +5801,19 @@ display_sys_stats(void) > > > > } > > > > } else { > > > > if (pc->system_map) { > > > > - fprintf(fp, " SYSTEM MAP: %s%s%s\n", > > > pc->system_map, > > > > + fprintf(fp, " SYSTEM MAP: %s%s%s%s\n", > > > > + pc->system_map, > > > > is_livepatch() ? " [LIVEPATCH]" > > > > : "", > > > > + is_livepatch_transition() ? " > > > > + [TRANSITION]" : "", > > > > is_kernel_tainted() ? " [TAINTED]" : ""); > > > > fprintf(fp, "DEBUG KERNEL: %s %s\n", > > > > pc->namelist_orig ? > > > > pc->namelist_orig : > > > > pc->namelist, > > > > > > > debug_kernel_version(pc->namelist)); > > > > } else > > > > - fprintf(fp, " KERNEL: %s%s%s\n", > > > pc->namelist_orig ? > > > > + fprintf(fp, " KERNEL: %s%s%s%s\n", > > > pc->namelist_orig ? > > > > pc->namelist_orig : pc->namelist, > > > > is_livepatch() ? " [LIVEPATCH]" > > > > : "", > > > > + is_livepatch_transition() ? " > > > > + [TRANSITION]" : "", > > > > is_kernel_tainted() ? " [TAINTED]" : ""); > > > > } > > > > > > > > -- > > > > 2.47.3 > > > > > >