[PATCH v6 15/18] perf: add PERF_RECORD_MISC_MMAP_DATA to RECORD_MMAP

Stephane Eranian
2013-01-15T15:50:05Z

Type of mapping was lost and made it hard for a tool
to distinguish code vs. data mmaps. Perf has the ability
to distinguish the two.

Use a bit in the header->misc bitmask to keep track of
the mmap type. If PERF_RECORD_MISC_MMAP_DATA is set then
the mapping is not executable (!VM_EXEC). If not set, then
the mapping is executable.

Signed-off-by: Stephane Eranian <eranian@google.com>
---
include/uapi/linux/perf_event.h | 1 +
kernel/events/core.c | 3 +++
2 files changed, 4 insertions(+)

diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_event.h
index 8283218..5b80f14 100644
--- a/include/uapi/linux/perf_event.h
+++ b/include/uapi/linux/perf_event.h
@@ -445,6 +445,7 @@ struct perf_event_mmap_page {
#define PERF_RECORD_MISC_GUEST_KERNEL (4 << 0)
#define PERF_RECORD_MISC_GUEST_USER (5 << 0)

+#define PERF_RECORD_MISC_MMAP_DATA (1 << 13)
/*
* Indicates that the content of PERF_SAMPLE_IP points to
* the actual instruction that triggered the event. See also
diff --git a/kernel/events/core.c b/kernel/events/core.c
index fd4ceea..8292f15 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -4764,6 +4764,9 @@ static void perf_event_mmap_event(struct perf_mmap_event *mmap_event)
mmap_event->file_name = name;
mmap_event->file_size = size;

+ if (!(vma->vm_flags & VM_EXEC))
+ mmap_event->event_id.header.misc |= PERF_RECORD_MISC_MMAP_DATA;
+
mmap_event->event_id.header.size = sizeof(mmap_event->event_id) + size;

rcu_read_lock();
--
1.7.9.5