x86/mm: Get rid of VM_BUG_ON in switch_tlb_irqs_off()
If we hit the VM_BUG_ON(), we're detecting a genuinely bad situation, but we're very unlikely to get a useful call trace. Make it a warning instead. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bpetkov@suse.de> Cc: Jiri Kosina <jikos@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/3b4e06bbb382ca54a93218407c93925ff5871546.1504847163.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Родитель
6d8ef53e8b
Коммит
a376e7f99b
|
@ -121,8 +121,28 @@ void switch_mm_irqs_off(struct mm_struct *prev, struct mm_struct *next,
|
|||
* hypothetical buggy code that directly switches to swapper_pg_dir
|
||||
* without going through leave_mm() / switch_mm_irqs_off() or that
|
||||
* does something like write_cr3(read_cr3_pa()).
|
||||
*
|
||||
* Only do this check if CONFIG_DEBUG_VM=y because __read_cr3()
|
||||
* isn't free.
|
||||
*/
|
||||
VM_BUG_ON(__read_cr3() != (__sme_pa(real_prev->pgd) | prev_asid));
|
||||
#ifdef CONFIG_DEBUG_VM
|
||||
if (WARN_ON_ONCE(__read_cr3() !=
|
||||
(__sme_pa(real_prev->pgd) | prev_asid))) {
|
||||
/*
|
||||
* If we were to BUG here, we'd be very likely to kill
|
||||
* the system so hard that we don't see the call trace.
|
||||
* Try to recover instead by ignoring the error and doing
|
||||
* a global flush to minimize the chance of corruption.
|
||||
*
|
||||
* (This is far from being a fully correct recovery.
|
||||
* Architecturally, the CPU could prefetch something
|
||||
* back into an incorrect ASID slot and leave it there
|
||||
* to cause trouble down the road. It's better than
|
||||
* nothing, though.)
|
||||
*/
|
||||
__flush_tlb_all();
|
||||
}
|
||||
#endif
|
||||
|
||||
if (real_prev == next) {
|
||||
VM_BUG_ON(this_cpu_read(cpu_tlbstate.ctxs[prev_asid].ctx_id) !=
|
||||
|
|
Загрузка…
Ссылка в новой задаче