Author: markj Date: Sat Feb 29 18:41:48 2020 New Revision: 358470 URL: https://svnweb.freebsd.org/changeset/base/358470
Log: Ensure that arm64 thread structures are allocated from the direct map. Otherwise we can fail to handle translation faults on curthread, leading to a panic. Reviewed by: alc, rlibby Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D23895 Modified: head/sys/kern/kern_thread.c Modified: head/sys/kern/kern_thread.c ============================================================================== --- head/sys/kern/kern_thread.c Sat Feb 29 17:24:02 2020 (r358469) +++ head/sys/kern/kern_thread.c Sat Feb 29 18:41:48 2020 (r358470) @@ -331,6 +331,7 @@ proc_linkup(struct proc *p, struct thread *td) void threadinit(void) { + uint32_t flags; mtx_init(&tid_lock, "TID lock", NULL, MTX_DEF); @@ -340,9 +341,20 @@ threadinit(void) */ tid_unrhdr = new_unrhdr(PID_MAX + 2, INT_MAX, &tid_lock); + flags = UMA_ZONE_NOFREE; +#ifdef __aarch64__ + /* + * Force thread structures to be allocated from the direct map. + * Otherwise, superpage promotions and demotions may temporarily + * invalidate thread structure mappings. For most dynamically allocated + * structures this is not a problem, but translation faults cannot be + * handled without accessing curthread. + */ + flags |= UMA_ZONE_CONTIG; +#endif thread_zone = uma_zcreate("THREAD", sched_sizeof_thread(), thread_ctor, thread_dtor, thread_init, thread_fini, - 32 - 1, UMA_ZONE_NOFREE); + 32 - 1, flags); tidhashtbl = hashinit(maxproc / 2, M_TIDHASH, &tidhash); rw_init(&tidhash_lock, "tidhash"); } _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
