[Crash-utility] Re: [PATCH] Fix incorrect 'bt -v' output suggesting overflow

Date: Sat, 14 Dec 2024 18:01:14 -0500 From: Lucas Oakley <soakley(a)redhat.com&gt; Subject: [Crash-utility] [PATCH] Fix incorrect 'bt -v' output suggesting overflow To: devel(a)lists.crash-utility.osci.io Message-ID: <20241214230114.2854910-1-soakley(a)redhat.com&gt; Content-Type: text/plain; charset="US-ASCII"; x-default=true Change check_stack_overflow() to check if the thread_info's cpu member is smaller than possible existing CPUs, rather than the kernel table's cpu number (kt->cpus). The kernel table's cpu number is changed on some architectures to reflect the highest numbered online cpu + 1. This can cause a false positive in check_stack_overflow() if the cpu member of a parked task's thread_info structure, assigned to an offlined cpu, is larger than the kt->cpus but lower than the number of existing logical cpus. An example of this is RHEL 7 on s390x or RHEL 8 on ppc64le when the highest numbered CPU is offlined. Signed-off-by: Lucas Oakley <soakley(a)redhat.com&gt; --- task.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/task.c b/task.c index 33de7da..93dab0e 100644 --- a/task.c +++ b/task.c @@ -11253,12 +11253,12 @@ check_stack_overflow(void) cpu = 0; break; } - if (cpu >= kt->cpus) { + if (cpu >= get_cpus_present()) { if (!overflow) print_task_header(fp, tc, 0); fprintf(fp, " possible stack overflow: thread_info.cpu: %d >= %d\n", - cpu, kt->cpus); + cpu, get_cpus_present()); overflow++; total++; } }

2.47.1