Re: [Crash-utility] [crash patch] Compute init_thread_union size

----- Original Message ----- > On Thu, 2018-04-05 at 09:27 -0400, Dave Anderson wrote: > > > > ----- Original Message ----- > > > Greetings, > > > > > > I know absolutely nothing about how crash maintenance is done, and very > > > damn little about crash's gizzard, so please consider the below a bug > > > report, a patch.. or bloody annoying spam, as you see fit. > > > > Hi Mike, > > > > No, it's most definitely appreciated. Normally patches are posted on the > > crash utility mailing list (crash-utility(a)redhat.com), but this is fine. > > > > And speaking of the mailing list, there was a bug report and subsequent > > thread yesterday concerning this issue: > > > > https://www.redhat.com/archives/crash-utility/2018-April/msg00000.html > > > > It was unresolved because the thread_union still exists in the most > > recent upstream sources, and I can still see the union declaration > > in the most recent Fedora kernel. > > It still exists, but... > > homer:..kernel/linux-4.15 # objdump -t vmlinux|grep thread_union > ffffffff81e00000 g     O .data  0000000000004000 init_thread_union > ^^^^ > homer:..kernel/linux-master # objdump -t vmlinux|grep thread_union > ffffffff81e00000 g       .data  0000000000000000 init_thread_union > ^^^^ > > ...it's size went missing at the referenced commit. Right, but the crash utility never dealt with the "init_thread_union" data symbol, but rather uses the declaration of the "thread_union" union, which still exists in today's linux-git: union thread_union { #ifndef CONFIG_ARCH_TASK_STRUCT_ON_STACK struct task_struct task; #endif #ifndef CONFIG_THREAD_INFO_IN_TASK struct thread_info thread_info; #endif unsigned long stack[THREAD_SIZE/sizeof(long)]; }; So I'm guessing that the x86_64 arch never references the thread_union from include/linux/sched.h, and therefore has no need to put it in the vmlinux debuginfo data?