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perf: Add non-exec mmap() tracking
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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 <[email protected]>
[Updated code for stable perf ABI]
Signed-off-by: Eric B Munson <[email protected]>
Signed-off-by: Peter Zijlstra <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Mike Galbraith <[email protected]>
Cc: Steven Rostedt <[email protected]>
LKML-Reference: <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
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@khers
khers authored and Ingo Molnar committed Jun 9, 2010
1 parent 8ed9228 commit 3af9e85
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Showing 5 changed files with 35 additions and 22 deletions.
1 change: 1 addition & 0 deletions fs/exec.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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;
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12 changes: 3 additions & 9 deletions include/linux/perf_event.h
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Original file line number Diff line number Diff line change
Expand Up @@ -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 */
Expand Down Expand Up @@ -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);
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34 changes: 23 additions & 11 deletions kernel/perf_event.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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);
Expand Down Expand Up @@ -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 {
Expand Down Expand Up @@ -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;
Expand Down Expand Up @@ -3766,27 +3767,30 @@ 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;

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);
}
}
Expand Down Expand Up @@ -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));
Expand All @@ -3846,17 +3858,17 @@ static void perf_event_mmap_event(struct perf_mmap_event *mmap_event)

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;

Expand Down Expand Up @@ -4911,7 +4923,7 @@ perf_event_alloc(struct perf_event_attr *attr,

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);
Expand Down
6 changes: 5 additions & 1 deletion mm/mmap.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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;
Expand Down Expand Up @@ -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);
Expand Down Expand Up @@ -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))
Expand Down
4 changes: 3 additions & 1 deletion tools/perf/builtin-record.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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;
Expand Down

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