[PATCH 1/2] Add trace points to mmap, munmap, and brk

From: Eric B Munson
Date: Mon Jul 19 2010 - 13:07:07 EST


This patch adds trace points to mmap, munmap, and brk that will report
relevant addresses and sizes before each function exits successfully.

Signed-off-by: Eric B Munson <emunson@xxxxxxxxx>
---
include/trace/events/mm.h | 75 +++++++++++++++++++++++++++++++++++++++++++++
mm/mmap.c | 15 ++++++++-
2 files changed, 89 insertions(+), 1 deletions(-)
create mode 100644 include/trace/events/mm.h

diff --git a/include/trace/events/mm.h b/include/trace/events/mm.h
new file mode 100644
index 0000000..892bbe3
--- /dev/null
+++ b/include/trace/events/mm.h
@@ -0,0 +1,75 @@
+/*
+ * Copyright (c) 2010, Eric Munson
+ * All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM mm
+
+#if !defined(_TRACE_MM_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_MM_H
+
+#include <linux/tracepoint.h>
+
+DECLARE_EVENT_CLASS(
+ mm_mmap_class,
+ TP_PROTO(unsigned long addr, unsigned long len),
+ TP_ARGS(addr, len),
+ TP_STRUCT__entry(
+ __field(unsigned long, addr)
+ __field(unsigned long, len)
+ ),
+ TP_fast_assign(
+ __entry->addr = addr;
+ __entry->len = len;
+ ),
+ TP_printk("%lu bytes at 0x%lx\n", __entry->len, __entry->addr)
+);
+
+DEFINE_EVENT(
+ mm_mmap_class,
+ mmap,
+ TP_PROTO(unsigned long addr, unsigned long len),
+ TP_ARGS(addr, len)
+);
+
+
+DEFINE_EVENT(
+ mm_mmap_class,
+ brk,
+ TP_PROTO(unsigned long addr, unsigned long len),
+ TP_ARGS(addr, len)
+);
+
+TRACE_EVENT(
+ munmap,
+ TP_PROTO(unsigned long start, size_t len),
+ TP_ARGS(start, len),
+ TP_STRUCT__entry(
+ __field(unsigned long, start)
+ __field(size_t, len)
+ ),
+ TP_fast_assign(
+ __entry->start = start;
+ __entry->len = len;
+ ),
+
+ TP_printk("%u bytes at 0x%lx\n", __entry->len, __entry->start)
+);
+
+#endif /* _TRACE_MM_H */
+
+#include <trace/define_trace.h>
+
diff --git a/mm/mmap.c b/mm/mmap.c
index 456ec6f..430ce46 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -29,6 +29,9 @@
#include <linux/mmu_notifier.h>
#include <linux/perf_event.h>

+#define CREATE_TRACE_POINTS
+#include <trace/events/mm.h>
+
#include <asm/uaccess.h>
#include <asm/cacheflush.h>
#include <asm/tlb.h>
@@ -949,6 +952,7 @@ unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,
unsigned int vm_flags;
int error;
unsigned long reqprot = prot;
+ unsigned long ret;

/*
* Does the application expect PROT_READ to imply PROT_EXEC?
@@ -1074,7 +1078,12 @@ unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,
if (error)
return error;

- return mmap_region(file, addr, len, flags, vm_flags, pgoff);
+ ret = mmap_region(file, addr, len, flags, vm_flags, pgoff);
+
+ if(!(ret & ~PAGE_MASK))
+ trace_mmap(addr,len);
+
+ return ret;
}
EXPORT_SYMBOL(do_mmap_pgoff);

@@ -2079,6 +2088,8 @@ int do_munmap(struct mm_struct *mm, unsigned long start, size_t len)
}
}

+ trace_munmap(start, len);
+
/*
* Remove the vma's, and unmap the actual pages
*/
@@ -2213,6 +2224,8 @@ out:
if (!mlock_vma_pages_range(vma, addr, addr + len))
mm->locked_vm += (len >> PAGE_SHIFT);
}
+
+ trace_brk(addr, len);
return addr;
}

--
1.7.0.4

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