perf: Add non-exec mmap() tracking

Add the capacility to track data mmap()s. This can be used together
with PERF_SAMPLE_ADDR for data profiling.

Signed-off-by: Anton Blanchard <anton@samba.org>
[Updated code for stable perf ABI]
Signed-off-by: Eric B Munson <ebmunson@us.ibm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <1274193049-25997-1-git-send-email-ebmunson@us.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

5 files changed, 35 insertions, 22 deletions

diff --git a/fs/exec.c b/fs/exec.c
index e19de6a80339..97d91a03fb13 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -653,6 +653,7 @@ int setup_arg_pages(struct linux_binprm *bprm,
         else
                 stack_base = vma->vm_start - stack_expand;
 #endif
+        current->mm->start_stack = bprm->p;
         ret = expand_stack(vma, stack_base);
         if (ret)
                 ret = -EFAULT;
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index c691a0b27bcd..36efad90cd43 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -214,8 +214,9 @@ struct perf_event_attr {
                                  *  See also PERF_RECORD_MISC_EXACT_IP
                                  */
                                 precise_ip     :  2, /* skid constraint       */
+                                mmap_data      :  1, /* non-exec mmap data    */
 
-                                __reserved_1   : 47;
+                                __reserved_1   : 46;
 
         union {
                 __u32           wakeup_events;    /* wakeup every n events */
@@ -962,14 +963,7 @@ perf_sw_event(u32 event_id, u64 nr, int nmi, struct pt_regs *regs, u64 addr)
         }
 }
 
-extern void __perf_event_mmap(struct vm_area_struct *vma);
-
-static inline void perf_event_mmap(struct vm_area_struct *vma)
-{
-        if (vma->vm_flags & VM_EXEC)
-                __perf_event_mmap(vma);
-}
-
+extern void perf_event_mmap(struct vm_area_struct *vma);
 extern struct perf_guest_info_callbacks *perf_guest_cbs;
 extern int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks *callbacks);
 extern int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks *callbacks);
diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index b39bec346e80..227ed9c8ec34 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -1891,7 +1891,7 @@ static void free_event(struct perf_event *event)
 
         if (!event->parent) {
                 atomic_dec(&nr_events);
-                if (event->attr.mmap)
+                if (event->attr.mmap || event->attr.mmap_data)
                         atomic_dec(&nr_mmap_events);
                 if (event->attr.comm)
                         atomic_dec(&nr_comm_events);
@@ -3491,7 +3491,7 @@ perf_event_read_event(struct perf_event *event,
 /*
  * task tracking -- fork/exit
  *
- * enabled by: attr.comm | attr.mmap | attr.task
+ * enabled by: attr.comm | attr.mmap | attr.mmap_data | attr.task
  */
 
 struct perf_task_event {
@@ -3541,7 +3541,8 @@ static int perf_event_task_match(struct perf_event *event)
         if (event->cpu != -1 && event->cpu != smp_processor_id())
                 return 0;
 
-        if (event->attr.comm || event->attr.mmap || event->attr.task)
+        if (event->attr.comm || event->attr.mmap ||
+            event->attr.mmap_data || event->attr.task)
                 return 1;
 
         return 0;
@@ -3766,7 +3767,8 @@ static void perf_event_mmap_output(struct perf_event *event,
 }
 
 static int perf_event_mmap_match(struct perf_event *event,
-                                   struct perf_mmap_event *mmap_event)
+                                   struct perf_mmap_event *mmap_event,
+                                   int executable)
 {
         if (event->state < PERF_EVENT_STATE_INACTIVE)
                 return 0;
@@ -3774,19 +3776,21 @@ static int perf_event_mmap_match(struct perf_event *event,
         if (event->cpu != -1 && event->cpu != smp_processor_id())
                 return 0;
 
-        if (event->attr.mmap)
+        if ((!executable && event->attr.mmap_data) ||
+            (executable && event->attr.mmap))
                 return 1;
 
         return 0;
 }
 
 static void perf_event_mmap_ctx(struct perf_event_context *ctx,
-                                  struct perf_mmap_event *mmap_event)
+                                  struct perf_mmap_event *mmap_event,
+                                  int executable)
 {
         struct perf_event *event;
 
         list_for_each_entry_rcu(event, &ctx->event_list, event_entry) {
-                if (perf_event_mmap_match(event, mmap_event))
+                if (perf_event_mmap_match(event, mmap_event, executable))
                         perf_event_mmap_output(event, mmap_event);
         }
 }
@@ -3830,6 +3834,14 @@ static void perf_event_mmap_event(struct perf_mmap_event *mmap_event)
                 if (!vma->vm_mm) {
                         name = strncpy(tmp, "[vdso]", sizeof(tmp));
                         goto got_name;
+                } else if (vma->vm_start <= vma->vm_mm->start_brk &&
+                                vma->vm_end >= vma->vm_mm->brk) {
+                        name = strncpy(tmp, "[heap]", sizeof(tmp));
+                        goto got_name;
+                } else if (vma->vm_start <= vma->vm_mm->start_stack &&
+                                vma->vm_end >= vma->vm_mm->start_stack) {
+                        name = strncpy(tmp, "[stack]", sizeof(tmp));
+                        goto got_name;
                 }
 
                 name = strncpy(tmp, "//anon", sizeof(tmp));
@@ -3846,17 +3858,17 @@ got_name:
 
         rcu_read_lock();
         cpuctx = &get_cpu_var(perf_cpu_context);
-        perf_event_mmap_ctx(&cpuctx->ctx, mmap_event);
+        perf_event_mmap_ctx(&cpuctx->ctx, mmap_event, vma->vm_flags & VM_EXEC);
         ctx = rcu_dereference(current->perf_event_ctxp);
         if (ctx)
-                perf_event_mmap_ctx(ctx, mmap_event);
+                perf_event_mmap_ctx(ctx, mmap_event, vma->vm_flags & VM_EXEC);
         put_cpu_var(perf_cpu_context);
         rcu_read_unlock();
 
         kfree(buf);
 }
 
-void __perf_event_mmap(struct vm_area_struct *vma)
+void perf_event_mmap(struct vm_area_struct *vma)
 {
         struct perf_mmap_event mmap_event;
 
@@ -4911,7 +4923,7 @@ done:
 
         if (!event->parent) {
                 atomic_inc(&nr_events);
-                if (event->attr.mmap)
+                if (event->attr.mmap || event->attr.mmap_data)
                         atomic_inc(&nr_mmap_events);
                 if (event->attr.comm)
                         atomic_inc(&nr_comm_events);
diff --git a/mm/mmap.c b/mm/mmap.c
index 456ec6f27889..e38e910cb756 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1734,8 +1734,10 @@ int expand_upwards(struct vm_area_struct *vma, unsigned long address)
                 grow = (address - vma->vm_end) >> PAGE_SHIFT;
 
                 error = acct_stack_growth(vma, size, grow);
-                if (!error)
+                if (!error) {
                         vma->vm_end = address;
+                        perf_event_mmap(vma);
+                }
         }
         anon_vma_unlock(vma);
         return error;
@@ -1781,6 +1783,7 @@ static int expand_downwards(struct vm_area_struct *vma,
                 if (!error) {
                         vma->vm_start = address;
                         vma->vm_pgoff -= grow;
+                        perf_event_mmap(vma);
                 }
         }
         anon_vma_unlock(vma);
@@ -2208,6 +2211,7 @@ unsigned long do_brk(unsigned long addr, unsigned long len)
         vma->vm_page_prot = vm_get_page_prot(flags);
         vma_link(mm, vma, prev, rb_link, rb_parent);
 out:
+        perf_event_mmap(vma);
         mm->total_vm += len >> PAGE_SHIFT;
         if (flags & VM_LOCKED) {
                 if (!mlock_vma_pages_range(vma, addr, addr + len))
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 5e5c6403a315..39c7247bc54a 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -268,8 +268,10 @@ static void create_counter(int counter, int cpu)
         if (inherit_stat)
                 attr->inherit_stat = 1;
 
-        if (sample_address)
+        if (sample_address) {
                 attr->sample_type       |= PERF_SAMPLE_ADDR;
+                attr->mmap_data = track;
+        }
 
         if (call_graph)
                 attr->sample_type       |= PERF_SAMPLE_CALLCHAIN;