[PATCH] Don't overwrite magic in trace

[blktrace.git] / blkparse.c

diff --git a/blkparse.c b/blkparse.c
index 342f5f61e9130f60ab1e399ef5acf754703c7895..9f60dcf48e098b271fa5470015f2703a1545adc9 100644 (file)
--- a/blkparse.c
+++ b/blkparse.c
@@ -28,6 +28,7 @@ static struct rb_root rb_root;
 
 struct trace {
        struct blk_io_trace *bit;
+       unsigned int cpu;
        struct rb_node rb_node;
 };
 
@@ -290,7 +291,22 @@ static inline int trace_rb_insert(struct trace *t)
        return 0;
 }
 
-static int sort_entries(void *traces, unsigned long offset)
+static inline int verify_trace(struct blk_io_trace *t)
+{
+       if (!CHECK_MAGIC(t)) {
+               fprintf(stderr, "bad trace magic %x\n", t->magic);
+               return 1;
+       }
+       if ((t->magic & 0xff) != SUPPORTED_VERSION) {
+               fprintf(stderr, "unsupported trace version %x\n", 
+                       t->magic & 0xff);
+               return 1;
+       }
+
+       return 0;
+}
+
+static int sort_entries(void *traces, unsigned long offset, int cpu)
 {
        struct blk_io_trace *bit;
        struct trace *t;
@@ -303,8 +319,12 @@ static int sort_entries(void *traces, unsigned long offset)
                bit = traces;
                t = malloc(sizeof(*t));
                t->bit = bit;
+               t->cpu = cpu;
                memset(&t->rb_node, 0, sizeof(t->rb_node));
 
+               if (verify_trace(bit))
+                       break;
+
                if (trace_rb_insert(t))
                        return -1;
 
@@ -330,7 +350,7 @@ static void show_entries(void)
                t = rb_entry(n, struct trace, rb_node);
                bit = t->bit;
 
-               cpu = bit->magic;
+               cpu = t->cpu;
                if (cpu > max_cpus) {
                        fprintf(stderr, "CPU number too large (%d)\n", cpu);
                        break;
@@ -400,7 +420,7 @@ int main(int argc, char *argv[])
                        break;
                }
 
-               ret = sort_entries(tb, st.st_size);
+               ret = sort_entries(tb, st.st_size, i);
                if (ret == -1)
                        break;