diff mbox series

[v2,2/4] powerpc: select ARCH_WANT_IRQS_OFF_ACTIVATE_MM

Message ID 20200914045219.3736466-3-npiggin@gmail.com (mailing list archive)
State Accepted
Commit 66acd46080bd9e5ad2be4b0eb1d498d5145d058e
Headers show
Series more mm switching vs TLB shootdown and lazy tlb fixes | expand

Checks

Context Check Description
snowpatch_ozlabs/apply_patch warning Failed to apply on branch powerpc/merge (4b552a4cbf286ff9dcdab19153f3c1c7d1680fab)
snowpatch_ozlabs/apply_patch warning Failed to apply on branch powerpc/next (dc462267d2d7aacffc3c1d99b02d7a7c59db7c66)
snowpatch_ozlabs/apply_patch warning Failed to apply on branch linus/master (856deb866d16e29bd65952e0289066f6078af773)
snowpatch_ozlabs/apply_patch warning Failed to apply on branch powerpc/fixes (0460534b532e5518c657c7d6492b9337d975eaa3)
snowpatch_ozlabs/apply_patch warning Failed to apply on branch linux-next (d5b2251d63b5344ee827d3680fa79bdb9f9ddfa1)
snowpatch_ozlabs/apply_patch fail Failed to apply to any branch

Commit Message

Nicholas Piggin Sept. 14, 2020, 4:52 a.m. UTC 
powerpc uses IPIs in some situations to switch a kernel thread away
from a lazy tlb mm, which is subject to the TLB flushing race
described in the changelog introducing ARCH_WANT_IRQS_OFF_ACTIVATE_MM.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/Kconfig                   | 1 +
 arch/powerpc/include/asm/mmu_context.h | 2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 65bed1fdeaad..587ba8352d01 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -149,6 +149,7 @@  config PPC
 	select ARCH_USE_QUEUED_RWLOCKS		if PPC_QUEUED_SPINLOCKS
 	select ARCH_USE_QUEUED_SPINLOCKS	if PPC_QUEUED_SPINLOCKS
 	select ARCH_WANT_IPC_PARSE_VERSION
+	select ARCH_WANT_IRQS_OFF_ACTIVATE_MM
 	select ARCH_WEAK_RELEASE_ACQUIRE
 	select BINFMT_ELF
 	select BUILDTIME_TABLE_SORT
diff --git a/arch/powerpc/include/asm/mmu_context.h b/arch/powerpc/include/asm/mmu_context.h
index a3a12a8341b2..b42813359f49 100644
--- a/arch/powerpc/include/asm/mmu_context.h
+++ b/arch/powerpc/include/asm/mmu_context.h
@@ -244,7 +244,7 @@  static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
 #define activate_mm activate_mm
 static inline void activate_mm(struct mm_struct *prev, struct mm_struct *next)
 {
-	switch_mm(prev, next, current);
+	switch_mm_irqs_off(prev, next, current);
 }
 
 /* We don't currently use enter_lazy_tlb() for anything */