From 6055f6cf0d462fa0d9212a8279b6b0d1130552e1 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Tue, 13 Feb 2024 22:05:50 +0100 Subject: [PATCH] x86/smpboot: Make error message actually useful "smpboot: native_kick_ap: bad cpu 33" is absolutely useless information. Replace it with something meaningful which allows to decode the failure condition. Signed-off-by: Thomas Gleixner Tested-by: Michael Kelley Tested-by: Sohil Mehta Link: https://lore.kernel.org/r/20240213210252.170806023@linutronix.de --- arch/x86/kernel/smpboot.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index bfb99b5c56061..d850faca946d1 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -1072,9 +1072,13 @@ int native_kick_ap(unsigned int cpu, struct task_struct *tidle) pr_debug("++++++++++++++++++++=_---CPU UP %u\n", cpu); - if (apicid == BAD_APICID || !test_bit(apicid, phys_cpu_present_map) || - !apic_id_valid(apicid)) { - pr_err("%s: bad cpu %d\n", __func__, cpu); + if (apicid == BAD_APICID || !apic_id_valid(apicid)) { + pr_err("CPU %u has invalid APIC ID %x. Aborting bringup\n", cpu, apicid); + return -EINVAL; + } + + if (!test_bit(apicid, phys_cpu_present_map)) { + pr_err("CPU %u APIC ID %x is not present. Aborting bringup\n", cpu, apicid); return -EINVAL; }