1 files changed, 145 insertions, 0 deletions

diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c
index c95e92329b97..f35e89e3d6a4 100644
--- a/kernel/perf_counter.c
+++ b/kernel/perf_counter.c
@@ -25,6 +25,7 @@
 #include <linux/anon_inodes.h>
 #include <linux/kernel_stat.h>
 #include <linux/perf_counter.h>
+#include <linux/dcache.h>
 
 #include <asm/irq_regs.h>
 
@@ -1844,6 +1845,150 @@ void perf_counter_output(struct perf_counter *counter,
 }
 
 /*
+ * mmap tracking
+ */
+
+struct perf_mmap_event {
+        struct file     *file;
+        char            *file_name;
+        int             file_size;
+
+        struct {
+                struct perf_event_header        header;
+
+                u32                             pid;
+                u32                             tid;
+                u64                             start;
+                u64                             len;
+                u64                             pgoff;
+        } event;
+};
+
+static void perf_counter_mmap_output(struct perf_counter *counter,
+                                     struct perf_mmap_event *mmap_event)
+{
+        struct perf_output_handle handle;
+        int size = mmap_event->event.header.size;
+        int ret = perf_output_begin(&handle, counter, size);
+
+        if (ret)
+                return;
+
+        perf_output_put(&handle, mmap_event->event);
+        perf_output_copy(&handle, mmap_event->file_name,
+                                   mmap_event->file_size);
+        perf_output_end(&handle, 0);
+}
+
+static int perf_counter_mmap_match(struct perf_counter *counter,
+                                   struct perf_mmap_event *mmap_event)
+{
+        if (counter->hw_event.mmap &&
+            mmap_event->event.header.type == PERF_EVENT_MMAP)
+                return 1;
+
+        if (counter->hw_event.munmap &&
+            mmap_event->event.header.type == PERF_EVENT_MUNMAP)
+                return 1;
+
+        return 0;
+}
+
+static void perf_counter_mmap_ctx(struct perf_counter_context *ctx,
+                                  struct perf_mmap_event *mmap_event)
+{
+        struct perf_counter *counter;
+
+        if (system_state != SYSTEM_RUNNING || list_empty(&ctx->event_list))
+                return;
+
+        rcu_read_lock();
+        list_for_each_entry_rcu(counter, &ctx->event_list, event_entry) {
+                if (perf_counter_mmap_match(counter, mmap_event))
+                        perf_counter_mmap_output(counter, mmap_event);
+        }
+        rcu_read_unlock();
+}
+
+static void perf_counter_mmap_event(struct perf_mmap_event *mmap_event)
+{
+        struct perf_cpu_context *cpuctx;
+        struct file *file = mmap_event->file;
+        unsigned int size;
+        char tmp[16];
+        char *buf = NULL;
+        char *name;
+
+        if (file) {
+                buf = kzalloc(PATH_MAX, GFP_KERNEL);
+                if (!buf) {
+                        name = strncpy(tmp, "//enomem", sizeof(tmp));
+                        goto got_name;
+                }
+                name = dentry_path(file->f_dentry, buf, PATH_MAX);
+                if (IS_ERR(name)) {
+                        name = strncpy(tmp, "//toolong", sizeof(tmp));
+                        goto got_name;
+                }
+        } else {
+                name = strncpy(tmp, "//anon", sizeof(tmp));
+                goto got_name;
+        }
+
+got_name:
+        size = ALIGN(strlen(name), sizeof(u64));
+
+        mmap_event->file_name = name;
+        mmap_event->file_size = size;
+
+        mmap_event->event.header.size = sizeof(mmap_event->event) + size;
+
+        cpuctx = &get_cpu_var(perf_cpu_context);
+        perf_counter_mmap_ctx(&cpuctx->ctx, mmap_event);
+        put_cpu_var(perf_cpu_context);
+
+        perf_counter_mmap_ctx(&current->perf_counter_ctx, mmap_event);
+
+        kfree(buf);
+}
+
+void perf_counter_mmap(unsigned long addr, unsigned long len,
+                       unsigned long pgoff, struct file *file)
+{
+        struct perf_mmap_event mmap_event = {
+                .file   = file,
+                .event  = {
+                        .header = { .type = PERF_EVENT_MMAP, },
+                        .pid    = current->group_leader->pid,
+                        .tid    = current->pid,
+                        .start  = addr,
+                        .len    = len,
+                        .pgoff  = pgoff,
+                },
+        };
+
+        perf_counter_mmap_event(&mmap_event);
+}
+
+void perf_counter_munmap(unsigned long addr, unsigned long len,
+                         unsigned long pgoff, struct file *file)
+{
+        struct perf_mmap_event mmap_event = {
+                .file   = file,
+                .event  = {
+                        .header = { .type = PERF_EVENT_MUNMAP, },
+                        .pid    = current->group_leader->pid,
+                        .tid    = current->pid,
+                        .start  = addr,
+                        .len    = len,
+                        .pgoff  = pgoff,
+                },
+        };
+
+        perf_counter_mmap_event(&mmap_event);
+}
+
+/*
  * Generic software counter infrastructure
  */