On Fri, Dec 7, 2018 at 11:35 PM Qian Cai <cai@xxxxxx> wrote: > > If the kernel is configured with KASAN_EXTRA, the stack size is > increasted significantly due to enable this option will set > -fstack-reuse to "none" in GCC [1]. As the results, it could trigger > stack overrun quite often with 32k stack size compiled using GCC 8. For > example, this reproducer > > size > 7536 shrink_inactive_list > 7440 shrink_page_list > 6560 fscache_stats_show > 3920 jbd2_journal_commit_transaction > 3216 try_to_unmap_one > 3072 migrate_page_move_mapping > 3584 migrate_misplaced_transhuge_page > 3920 ip_vs_lblcr_schedule > 4304 lpfc_nvme_info_show > 3888 lpfc_debugfs_nvmestat_data.constprop > > There are other 49 functions are over 2k in size while compiling kernel > with "-Wframe-larger-than=" on this machine. Hence, it is too much work > to change Makefiles for each object to compile without > -fsanitize-address-use-after-scope individually. > > [1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81715#c23 Could you clarify: are the numbers you see with or without the bugfix from that bugzilla? Arnd
