From: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
When batching TLB operations, we track the scope of the needed
TLB invalidation inside the 'struct mmu_gather'. With
mmu_gather->end, we indicate whether any operations required
a flush.
If the flush was not performed, then we know that no
pte_present() PTEs were found and no workaround is needed.
But, we do not know this unless tlb_flush_mmu_tlbonly()
tells us whether it flushed or not.
Have it return a bool to tell us.
Signed-off-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
---
b/arch/arm/include/asm/tlb.h | 3 ++-
b/arch/ia64/include/asm/tlb.h | 3 ++-
b/arch/s390/include/asm/tlb.h | 3 ++-
b/arch/sh/include/asm/tlb.h | 1 +
b/arch/um/include/asm/tlb.h | 3 ++-
b/mm/memory.c | 5 +++--
6 files changed, 12 insertions(+), 6 deletions(-)
diff -puN arch/arm/include/asm/tlb.h~knl-leak-50-bool-return-tlb_flush_mmu_tlbonly arch/arm/include/asm/tlb.h
--- a/arch/arm/include/asm/tlb.h~knl-leak-50-bool-return-tlb_flush_mmu_tlbonly 2016-06-30 17:10:42.947264449 -0700
+++ b/arch/arm/include/asm/tlb.h 2016-06-30 17:10:42.958264947 -0700
@@ -126,12 +126,13 @@ static inline void __tlb_alloc_page(stru
}
}
-static inline void tlb_flush_mmu_tlbonly(struct mmu_gather *tlb)
+static inline bool tlb_flush_mmu_tlbonly(struct mmu_gather *tlb)
{
tlb_flush(tlb);
#ifdef CONFIG_HAVE_RCU_TABLE_FREE
tlb_table_flush(tlb);
#endif
+ return true;
}
static inline void tlb_flush_mmu_free(struct mmu_gather *tlb)
diff -puN arch/ia64/include/asm/tlb.h~knl-leak-50-bool-return-tlb_flush_mmu_tlbonly arch/ia64/include/asm/tlb.h
--- a/arch/ia64/include/asm/tlb.h~knl-leak-50-bool-return-tlb_flush_mmu_tlbonly 2016-06-30 17:10:42.948264494 -0700
+++ b/arch/ia64/include/asm/tlb.h 2016-06-30 17:10:42.959264993 -0700
@@ -219,9 +219,10 @@ static inline int __tlb_remove_page(stru
return tlb->max - tlb->nr;
}
-static inline void tlb_flush_mmu_tlbonly(struct mmu_gather *tlb)
+static inline bool tlb_flush_mmu_tlbonly(struct mmu_gather *tlb)
{
ia64_tlb_flush_mmu_tlbonly(tlb, tlb->start_addr, tlb->end_addr);
+ return true;
}
static inline void tlb_flush_mmu_free(struct mmu_gather *tlb)
diff -puN arch/s390/include/asm/tlb.h~knl-leak-50-bool-return-tlb_flush_mmu_tlbonly arch/s390/include/asm/tlb.h
--- a/arch/s390/include/asm/tlb.h~knl-leak-50-bool-return-tlb_flush_mmu_tlbonly 2016-06-30 17:10:42.950264585 -0700
+++ b/arch/s390/include/asm/tlb.h 2016-06-30 17:10:42.960265038 -0700
@@ -60,9 +60,10 @@ static inline void tlb_gather_mmu(struct
tlb->batch = NULL;
}
-static inline void tlb_flush_mmu_tlbonly(struct mmu_gather *tlb)
+static inline bool tlb_flush_mmu_tlbonly(struct mmu_gather *tlb)
{
__tlb_flush_mm_lazy(tlb->mm);
+ return true;
}
static inline void tlb_flush_mmu_free(struct mmu_gather *tlb)
diff -puN arch/sh/include/asm/tlb.h~knl-leak-50-bool-return-tlb_flush_mmu_tlbonly arch/sh/include/asm/tlb.h
--- a/arch/sh/include/asm/tlb.h~knl-leak-50-bool-return-tlb_flush_mmu_tlbonly 2016-06-30 17:10:42.952264675 -0700
+++ b/arch/sh/include/asm/tlb.h 2016-06-30 17:10:42.960265038 -0700
@@ -89,6 +89,7 @@ tlb_end_vma(struct mmu_gather *tlb, stru
static inline void tlb_flush_mmu_tlbonly(struct mmu_gather *tlb)
{
+ return true;
}
static inline void tlb_flush_mmu_free(struct mmu_gather *tlb)
diff -puN arch/um/include/asm/tlb.h~knl-leak-50-bool-return-tlb_flush_mmu_tlbonly arch/um/include/asm/tlb.h
--- a/arch/um/include/asm/tlb.h~knl-leak-50-bool-return-tlb_flush_mmu_tlbonly 2016-06-30 17:10:42.953264721 -0700
+++ b/arch/um/include/asm/tlb.h 2016-06-30 17:10:42.960265038 -0700
@@ -59,10 +59,11 @@ tlb_gather_mmu(struct mmu_gather *tlb, s
extern void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start,
unsigned long end);
-static inline void
+static inline bool
tlb_flush_mmu_tlbonly(struct mmu_gather *tlb)
{
flush_tlb_mm_range(tlb->mm, tlb->start, tlb->end);
+ return true;
}
static inline void
diff -puN mm/memory.c~knl-leak-50-bool-return-tlb_flush_mmu_tlbonly mm/memory.c
--- a/mm/memory.c~knl-leak-50-bool-return-tlb_flush_mmu_tlbonly 2016-06-30 17:10:42.955264811 -0700
+++ b/mm/memory.c 2016-06-30 17:10:42.962265129 -0700
@@ -240,10 +240,10 @@ void tlb_gather_mmu(struct mmu_gather *t
__tlb_reset_range(tlb);
}
-static void tlb_flush_mmu_tlbonly(struct mmu_gather *tlb)
+static bool tlb_flush_mmu_tlbonly(struct mmu_gather *tlb)
{
if (!tlb->end)
- return;
+ return false;
tlb_flush(tlb);
mmu_notifier_invalidate_range(tlb->mm, tlb->start, tlb->end);
@@ -251,6 +251,7 @@ static void tlb_flush_mmu_tlbonly(struct
tlb_table_flush(tlb);
#endif
__tlb_reset_range(tlb);
+ return true;
}
static void tlb_flush_mmu_free(struct mmu_gather *tlb)
_
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