Andy Lutomirski 72c0098d92 x86/mm: Reinitialize TLB state on hotplug and resume ... When Linux brings a CPU down and back up, it switches to init_mm and then loads swapper_pg_dir into CR3. With PCID enabled, this has the side effect of masking off the ASID bits in CR3. This can result in some confusion in the TLB handling code. If we bring a CPU down and back up with any ASID other than 0, we end up with the wrong ASID active on the CPU after resume. This could cause our internal state to become corrupt, although major corruption is unlikely because init_mm doesn't have any user pages. More obviously, if CONFIG_DEBUG_VM=y, we'll trip over an assertion in the next context switch. The result of *that* is a failure to resume from suspend with probability 1 - 1/6^(cpus-1). Fix it by reinitializing cpu_tlbstate on resume and CPU bringup. Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Reported-by: Jiri Kosina <jikos@kernel.org> Fixes: 10af6235e0 ("x86/mm: Implement PCID based optimization: try to preserve old TLB entries using PCID") Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2017-09-06 20:12:57 -07:00
..
asm	x86/mm: Reinitialize TLB state on hotplug and resume	2017-09-06 20:12:57 -07:00
uapi/asm	x86/lguest: Remove lguest support	2017-08-24 09:57:28 +02:00