Mathieu Desnoyers 10bcc80e9d membarrier/x86: Provide core serializing command ...

There are two places where core serialization is needed by membarrier:

1) When returning from the membarrier IPI,
2) After scheduler updates curr to a thread with a different mm, before
   going back to user-space, since the curr->mm is used by membarrier to
   check whether it needs to send an IPI to that CPU.

x86-32 uses IRET as return from interrupt, and both IRET and SYSEXIT to go
back to user-space. The IRET instruction is core serializing, but not
SYSEXIT.

x86-64 uses IRET as return from interrupt, which takes care of the IPI.
However, it can return to user-space through either SYSRETL (compat
code), SYSRETQ, or IRET. Given that SYSRET{L,Q} is not core serializing,
we rely instead on write_cr3() performed by switch_mm() to provide core
serialization after changing the current mm, and deal with the special
case of kthread -> uthread (temporarily keeping current mm into
active_mm) by adding a sync_core() in that specific case.

Use the new sync_core_before_usermode() to guarantee this.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrea Parri <parri.andrea@gmail.com>
Cc: Andrew Hunter <ahh@google.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Avi Kivity <avi@scylladb.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Dave Watson <davejwatson@fb.com>
Cc: David Sehr <sehr@google.com>
Cc: Greg Hackmann <ghackmann@google.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Maged Michael <maged.michael@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-api@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Link: http://lkml.kernel.org/r/20180129202020.8515-10-mathieu.desnoyers@efficios.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

2018-02-05 21:35:11 +01:00

..

amdtopology.c

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02 11:10:55 +01:00

cpu_entry_area.c

x86/cpu_entry_area: Add debugstore entries to cpu_entry_area

2017-12-23 21:13:00 +01:00

debug_pagetables.c

x86/mm/dump_pagetables: Allow dumping current pagetables

2017-12-23 21:13:01 +01:00

dump_pagetables.c

x86/mm: Map cpu_entry_area at the same place on 4/5 level

2018-01-04 23:04:57 +01:00

extable.c

x86/extable: Mark exception handler functions visible

2018-01-14 20:04:16 +01:00

fault.c

x86/mm/64: Tighten up vmalloc_fault() sanity checks on 5-level kernels

2018-01-26 15:56:23 +01:00

highmem_32.c

x86/mm: Audit and remove any unnecessary uses of module.h

2016-07-14 13:04:20 +02:00

hugetlbpage.c

x86/mm: Prevent non-MAP_FIXED mapping across DEFAULT_MAP_WINDOW border

2017-11-16 11:43:11 +01:00

ident_map.c

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02 11:10:55 +01:00

init_32.c

x86/cpu_entry_area: Move it out of the fixmap

2017-12-22 20:13:05 +01:00

init_64.c

mm, sparse: do not swamp log with huge vmemmap allocation failures

2017-11-15 18:21:07 -08:00

init.c

Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2018-01-05 12:23:57 -08:00

iomap_32.c

x86/mm: Audit and remove any unnecessary uses of module.h

2016-07-14 13:04:20 +02:00

ioremap.c

x86/mm/kmmio: Fix mmiotrace for page unaligned addresses

2017-12-11 15:35:18 +01:00

kasan_init_64.c

x86/kasan: Panic if there is not enough memory to boot

2018-01-15 00:32:35 +01:00

kaslr.c

x86/kaslr: Fix the vaddr_end mess

2018-01-05 00:39:57 +01:00

kmmio.c

x86/mm/kmmio: Fix mmiotrace for page unaligned addresses

2017-12-11 15:35:18 +01:00

Makefile

Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2017-12-29 17:02:49 -08:00

mem_encrypt_boot.S

x86/mm: Encrypt the initrd earlier for BSP microcode update

2018-01-16 01:50:59 +01:00

mem_encrypt.c

x86: Use __nostackprotect for sme_encrypt_kernel

2018-01-20 17:22:54 -08:00

mm_internal.h

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02 11:10:55 +01:00

mmap.c

x86/mm: Limit mmap() of /dev/mem to valid physical addresses

2017-11-16 12:49:48 +01:00

mmio-mod.c

x86/boot/e820: Move asm/e820.h to asm/e820/api.h

2017-01-28 09:31:13 +01:00

mpx.c

Merge branch 'x86/mpx' into x86/asm, to pick up dependent commits

2017-11-08 10:55:48 +01:00

numa_32.c

x86/mm/32: Set the '__vmalloc_start_set' flag in initmem_init()

2017-05-09 08:12:27 +02:00

numa_64.c

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02 11:10:55 +01:00

numa_emulation.c

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02 11:10:55 +01:00

numa_internal.h

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02 11:10:55 +01:00

numa.c

Merge branch 'x86/boot' into x86/mm, to avoid conflict

2017-04-11 08:56:05 +02:00

pageattr-test.c

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02 11:10:55 +01:00

pageattr.c

kmemcheck: stop using GFP_NOTRACK and SLAB_NOTRACK

2017-11-15 18:21:04 -08:00

pat_internal.h

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02 11:10:55 +01:00

pat_rbtree.c

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02 11:10:55 +01:00

pat.c

x86/mm: Use proper encryption attributes with /dev/mem

2017-07-18 11:38:05 +02:00

pf_in.c

x86/mm: Audit and remove any unnecessary uses of module.h

2016-07-14 13:04:20 +02:00

pf_in.h

x86 mmiotrace: move files into arch/x86/mm/.

2008-05-24 11:25:37 +02:00

pgtable_32.c

x86/cpu_entry_area: Move it out of the fixmap

2017-12-22 20:13:05 +01:00

pgtable.c

Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2017-12-29 17:02:49 -08:00

physaddr.c

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02 11:10:55 +01:00

physaddr.h

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02 11:10:55 +01:00

pkeys.c

x86/fpu: Rename fpu::fpstate_active to fpu::initialized

2017-09-26 09:43:36 +02:00

pti.c

x86/mm/pti: Remove dead logic in pti_user_pagetable_walk*()

2018-01-08 17:42:13 +01:00

setup_nx.c

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02 11:10:55 +01:00

srat.c

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02 11:10:55 +01:00

testmmiotrace.c

Annotate hardware config module parameters in arch/x86/mm/

2017-04-04 16:54:21 +01:00

tlb.c

membarrier/x86: Provide core serializing command

2018-02-05 21:35:11 +01:00