linux/arch/x86/power
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
..
cpu.c x86/mm: Reinitialize TLB state on hotplug and resume 2017-09-06 20:12:57 -07:00
hibernate_32.c x86/mm: Convert trivial cases of page table walk to 5-level paging 2017-03-14 08:45:08 +01:00
hibernate_64.c Power management updates for v4.13-rc1 2017-07-04 13:39:41 -07:00
hibernate_asm_32.S x86, gdt, hibernate: Store/load GDT for hibernate path. 2013-05-02 11:27:35 -07:00
hibernate_asm_64.S x86/power/64: Do not refer to __PAGE_OFFSET from assembly code 2016-08-03 01:35:38 +02:00
Makefile objtool, x86: Add several functions and files to the objtool whitelist 2017-06-30 10:19:19 +02:00