perf_counter: executable mmap() information

[deliverable/linux.git] / kernel / perf_counter.c

diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c
index c95e92329b9781c8de7c10599adb069d6c23a8ce..f35e89e3d6a415886434b4bee2eb8bf7523f41ef 100644 (file)
--- 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>
 
@@ -1843,6 +1844,150 @@ 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
  */