d/freebsd-dev
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Ensure that arm64 thread structures are allocated from the direct map.

Browse Source 
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
This commit is contained in:
Mark Johnston 2020-02-29 18:41:48 +00:00
parent 8231202bd5
commit 5aa5420ff2
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=358470
1 changed files with 13 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

14
sys/kern/kern_thread.c
View File

@ -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");
}