x86/mpx: Trace allocation of new bounds tables

Bounds tables are a significant consumer of memory.  It is
important to know when they are being allocated.  Add a trace
point to trace whenever an allocation occurs and also its
virtual address.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20150607183704.EC23A93E@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

2 files changed, 17 insertions, 0 deletions

diff --git a/arch/x86/include/asm/trace/mpx.h b/arch/x86/include/asm/trace/mpx.h
index c13c6fa3fa92..173dd3ba108c 100644
--- a/arch/x86/include/asm/trace/mpx.h
+++ b/arch/x86/include/asm/trace/mpx.h
@@ -95,6 +95,22 @@ DEFINE_EVENT(mpx_range_trace, mpx_unmap_search,
         TP_ARGS(start, end)
 );
 
+TRACE_EVENT(mpx_new_bounds_table,
+
+        TP_PROTO(unsigned long table_vaddr),
+        TP_ARGS(table_vaddr),
+
+        TP_STRUCT__entry(
+                __field(unsigned long, table_vaddr)
+        ),
+
+        TP_fast_assign(
+                __entry->table_vaddr = table_vaddr;
+        ),
+
+        TP_printk("table vaddr:%p", (void *)__entry->table_vaddr)
+);
+
 #else
 
 /*
diff --git a/arch/x86/mm/mpx.c b/arch/x86/mm/mpx.c
index 55729ee9263e..c17fd27579af 100644
--- a/arch/x86/mm/mpx.c
+++ b/arch/x86/mm/mpx.c
@@ -483,6 +483,7 @@ static int allocate_bt(long __user *bd_entry)
                 ret = -EINVAL;
                 goto out_unmap;
         }
+        trace_mpx_new_bounds_table(bt_addr);
         return 0;
 out_unmap:
         vm_munmap(bt_addr & MPX_BT_ADDR_MASK, MPX_BT_SIZE_BYTES);