From: Dave Hansen <dave.han...@linux.intel.com>
This event traces any time we go looking to unmap a bounds table
for a given virtual address range. This is useful to ensure
that the kernel actually "tried" to free a bounds table versus
times it succeeded.
It might try and fail if it realized that a table was shared
with an adjacent VMA which is not being unmapped.
Signed-off-by: Dave Hansen <dave.han...@linux.intel.com>
---
b/arch/x86/include/asm/trace/mpx.h | 22 ++++++++++++++++++++++
b/arch/x86/mm/mpx.c | 1 +
2 files changed, 23 insertions(+)
diff -puN arch/x86/include/asm/trace/mpx.h~mpx-trace_unmap_search
arch/x86/include/asm/trace/mpx.h
--- a/arch/x86/include/asm/trace/mpx.h~mpx-trace_unmap_search 2015-03-27
14:35:05.987816914 -0700
+++ b/arch/x86/include/asm/trace/mpx.h 2015-03-27 14:35:05.992817139 -0700
@@ -75,6 +75,28 @@ TRACE_EVENT(mpx_unmap_zap,
)
);
+TRACE_EVENT(mpx_unmap_search,
+
+ TP_PROTO(unsigned long start,
+ unsigned long end),
+ TP_ARGS(start, end),
+
+ TP_STRUCT__entry(
+ __field(unsigned long, start)
+ __field(unsigned long, end)
+ ),
+
+ TP_fast_assign(
+ __entry->start = start;
+ __entry->end = end;
+ ),
+
+ TP_printk("[0x%p:0x%p]",
+ (void *)__entry->start,
+ (void *)__entry->end
+ )
+);
+
#else
/*
diff -puN arch/x86/mm/mpx.c~mpx-trace_unmap_search arch/x86/mm/mpx.c
--- a/arch/x86/mm/mpx.c~mpx-trace_unmap_search 2015-03-27 14:35:05.989817004
-0700
+++ b/arch/x86/mm/mpx.c 2015-03-27 14:35:05.992817139 -0700
@@ -843,6 +843,7 @@ static int mpx_unmap_tables(struct mm_st
long __user *bd_entry, *bde_start, *bde_end;
unsigned long bt_addr;
+ trace_mpx_unmap_search(start, end);
/*
* "Edge" bounds tables are those which are being used by the region
* (start -> end), but that may be shared with adjacent areas. If they
_
--
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