1 files changed, 84 insertions, 0 deletions

diff --git a/tools/perf/util/callchain.c b/tools/perf/util/callchain.c
index 08f0fbf5527c..ba7297230143 100644
--- a/tools/perf/util/callchain.c
+++ b/tools/perf/util/callchain.c
@@ -25,6 +25,90 @@
 
 __thread struct callchain_cursor callchain_cursor;
 
+#ifdef HAVE_DWARF_UNWIND_SUPPORT
+static int get_stack_size(const char *str, unsigned long *_size)
+{
+        char *endptr;
+        unsigned long size;
+        unsigned long max_size = round_down(USHRT_MAX, sizeof(u64));
+
+        size = strtoul(str, &endptr, 0);
+
+        do {
+                if (*endptr)
+                        break;
+
+                size = round_up(size, sizeof(u64));
+                if (!size || size > max_size)
+                        break;
+
+                *_size = size;
+                return 0;
+
+        } while (0);
+
+        pr_err("callchain: Incorrect stack dump size (max %ld): %s\n",
+               max_size, str);
+        return -1;
+}
+#endif /* HAVE_DWARF_UNWIND_SUPPORT */
+
+int parse_callchain_record_opt(const char *arg)
+{
+        char *tok, *name, *saveptr = NULL;
+        char *buf;
+        int ret = -1;
+
+        /* We need buffer that we know we can write to. */
+        buf = malloc(strlen(arg) + 1);
+        if (!buf)
+                return -ENOMEM;
+
+        strcpy(buf, arg);
+
+        tok = strtok_r((char *)buf, ",", &saveptr);
+        name = tok ? : (char *)buf;
+
+        do {
+                /* Framepointer style */
+                if (!strncmp(name, "fp", sizeof("fp"))) {
+                        if (!strtok_r(NULL, ",", &saveptr)) {
+                                callchain_param.record_mode = CALLCHAIN_FP;
+                                ret = 0;
+                        } else
+                                pr_err("callchain: No more arguments "
+                                       "needed for -g fp\n");
+                        break;
+
+#ifdef HAVE_DWARF_UNWIND_SUPPORT
+                /* Dwarf style */
+                } else if (!strncmp(name, "dwarf", sizeof("dwarf"))) {
+                        const unsigned long default_stack_dump_size = 8192;
+
+                        ret = 0;
+                        callchain_param.record_mode = CALLCHAIN_DWARF;
+                        callchain_param.dump_size = default_stack_dump_size;
+
+                        tok = strtok_r(NULL, ",", &saveptr);
+                        if (tok) {
+                                unsigned long size = 0;
+
+                                ret = get_stack_size(tok, &size);
+                                callchain_param.dump_size = size;
+                        }
+#endif /* HAVE_DWARF_UNWIND_SUPPORT */
+                } else {
+                        pr_err("callchain: Unknown --call-graph option "
+                               "value: %s\n", arg);
+                        break;
+                }
+
+        } while (0);
+
+        free(buf);
+        return ret;
+}
+
 int
 parse_callchain_report_opt(const char *arg)
 {