perf tools: Add machine__kernel_ip()

Add a function to determine if an address is in the kernel.  This is
based on the kernel function kernel_ip().

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1408129739-17368-5-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

3 files changed, 43 insertions, 3 deletions

diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c
index 1398c83d896d..ed558191c0b3 100644
--- a/tools/perf/util/event.c
+++ b/tools/perf/util/event.c
@@ -784,9 +784,9 @@ try_again:
                  * "[vdso]" dso, but for now lets use the old trick of looking
                  * in the whole kernel symbol list.
                  */
-                if ((long long)al->addr < 0 &&
-                    cpumode == PERF_RECORD_MISC_USER &&
-                    machine && mg != &machine->kmaps) {
+                if (cpumode == PERF_RECORD_MISC_USER && machine &&
+                    mg != &machine->kmaps &&
+                    machine__kernel_ip(machine, al->addr)) {
                         mg = &machine->kmaps;
                         load_map = true;
                         goto try_again;
diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index 37f8dc557ec0..e00daf0d2bde 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -32,6 +32,7 @@ int machine__init(struct machine *machine, const char *root_dir, pid_t pid)
         machine->symbol_filter = NULL;
         machine->id_hdr_size = 0;
         machine->comm_exec = false;
+        machine->kernel_start = 0;
 
         machine->root_dir = strdup(root_dir);
         if (machine->root_dir == NULL)
@@ -1559,3 +1560,25 @@ int machine__set_current_tid(struct machine *machine, int cpu, pid_t pid,
 
         return 0;
 }
+
+int machine__get_kernel_start(struct machine *machine)
+{
+        struct map *map = machine__kernel_map(machine, MAP__FUNCTION);
+        int err = 0;
+
+        /*
+         * The only addresses above 2^63 are kernel addresses of a 64-bit
+         * kernel.  Note that addresses are unsigned so that on a 32-bit system
+         * all addresses including kernel addresses are less than 2^32.  In
+         * that case (32-bit system), if the kernel mapping is unknown, all
+         * addresses will be assumed to be in user space - see
+         * machine__kernel_ip().
+         */
+        machine->kernel_start = 1ULL << 63;
+        if (map) {
+                err = map__load(map, machine->symbol_filter);
+                if (map->start)
+                        machine->kernel_start = map->start;
+        }
+        return err;
+}
diff --git a/tools/perf/util/machine.h b/tools/perf/util/machine.h
index 61216e028319..6a6bcc1cff54 100644
--- a/tools/perf/util/machine.h
+++ b/tools/perf/util/machine.h
@@ -36,6 +36,7 @@ struct machine {
         struct list_head  kernel_dsos;
         struct map_groups kmaps;
         struct map        *vmlinux_maps[MAP__NR_TYPES];
+        u64               kernel_start;
         symbol_filter_t   symbol_filter;
         pid_t             *current_tid;
 };
@@ -46,6 +47,22 @@ struct map *machine__kernel_map(struct machine *machine, enum map_type type)
         return machine->vmlinux_maps[type];
 }
 
+int machine__get_kernel_start(struct machine *machine);
+
+static inline u64 machine__kernel_start(struct machine *machine)
+{
+        if (!machine->kernel_start)
+                machine__get_kernel_start(machine);
+        return machine->kernel_start;
+}
+
+static inline bool machine__kernel_ip(struct machine *machine, u64 ip)
+{
+        u64 kernel_start = machine__kernel_start(machine);
+
+        return ip >= kernel_start;
+}
+
 struct thread *machine__find_thread(struct machine *machine, pid_t pid,
                                     pid_t tid);
 struct comm *machine__thread_exec_comm(struct machine *machine,