Currently, it's hard to debug panic issues caused by kill init on arm64, since there is no debug info from user mode in current panic msg such as the user_regs and maps info. This patch shows signal info sent to the global init, which will be helpful for debugging kill init issue caused by unhandled exception from user mode. - changes history: v3: https://lore.kernel.org/all/20240922095504.7182-1-qiwu.chen@xxxxxxxxxxxxx/ https://lore.kernel.org/all/20240922095504.7182-2-qiwu.chen@xxxxxxxxxxxxx/ v2: https://lore.kernel.org/all/20231110031553.33186-1-qiwu.chen@xxxxxxxxxxxxx/ v1: https://lore.kernel.org/all/20231110022720.GA3087@rlk/ Signed-off-by: qiwu.chen <qiwu.chen@xxxxxxxxxxxxx> --- arch/arm64/kernel/traps.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c index 563cbce11126..3150fb84195f 100644 --- a/arch/arm64/kernel/traps.c +++ b/arch/arm64/kernel/traps.c @@ -247,12 +247,20 @@ static void arm64_show_signal(int signo, const char *str) unsigned long esr = tsk->thread.fault_code; struct pt_regs *regs = task_pt_regs(tsk); + /* + * The signal sent to the global init needs to be shown, + * which is useful for debugging kill init issue. + */ + if (unlikely(is_global_init(tsk))) + goto dump; + /* Leave if the signal won't be shown */ if (!show_unhandled_signals || !unhandled_signal(tsk, signo) || !__ratelimit(&rs)) return; +dump: pr_info("%s[%d]: unhandled exception: ", tsk->comm, task_pid_nr(tsk)); if (esr) pr_cont("%s, ESR 0x%016lx, ", esr_get_class_string(esr), esr); -- 2.25.1
