misc: tegra-profiler: add unwind information

[sojka/nv-tegra/linux-3.10.git] / drivers / misc / tegra-profiler / comm.c

diff --git a/drivers/misc/tegra-profiler/comm.c b/drivers/misc/tegra-profiler/comm.c
index 9820f428c54c897fb3dd47b5011b346328a22f10..428059a328c0e22d05d3c804e747e9b714e1b79c 100644 (file)
--- a/drivers/misc/tegra-profiler/comm.c
+++ b/drivers/misc/tegra-profiler/comm.c
@@ -254,7 +254,7 @@ static ssize_t read_sample(char __user *buffer, size_t max_length)
 {
        u32 sed;
        unsigned int type;
-       int retval = -EIO, ip_size;
+       int retval = -EIO, ip_size, bt_size;
        int was_read = 0, write_offset = 0;
        unsigned long flags;
        struct quadd_ring_buffer *rb = &comm_ctx.rb;
@@ -294,7 +294,12 @@ static ssize_t read_sample(char __user *buffer, size_t max_length)
                ip_size = (sed & QUADD_SED_IP64) ?
                        sizeof(u64) : sizeof(u32);
 
-               length_extra = sample->callchain_nr * ip_size;
+               bt_size = sample->callchain_nr;
+
+               length_extra = bt_size * ip_size;
+
+               if (bt_size > 0)
+                       length_extra += DIV_ROUND_UP(bt_size, 8) * sizeof(u32);
 
                nr_events = __sw_hweight32(sample->events_flags);
                length_extra += nr_events * sizeof(u32);