trace: fixup CTF event description at registration

CTF event description is currently built by appending all fields in a
single string at trace point registration.
When dumping the metadata, this string is split again and inspected to
fixup reserved keywords and special tokens like "." or "->".

Move this fixup per field at trace point registration time so that there
is no need for inspecting / string parsing when dumping metadata.
Use dynamic allocations to remove an artificial size limit on the CTF
event description manipulations.

Signed-off-by: David Marchand <david.marchand@redhat.com>
Acked-by: Sunil Kumar Kori <skori@mavell.com>

diff --git a/lib/librte_eal/common/eal_common_trace.c b/lib/librte_eal/common/eal_common_trace.c
index b6da553..80b458e 100644 (file)
--- a/lib/librte_eal/common/eal_common_trace.c
+++ b/lib/librte_eal/common/eal_common_trace.c
@@ -432,11 +432,16 @@ __rte_trace_point_emit_field(size_t sz, const char *in, const char *datatype)
        char *field = RTE_PER_LCORE(ctf_field);
        int count = RTE_PER_LCORE(ctf_count);
        size_t size;
+       char *fixup;
        int rc;
 
        size = RTE_MAX(0, TRACE_CTF_FIELD_SIZE - 1 - count);
        RTE_PER_LCORE(trace_point_sz) += sz;
+       fixup = trace_metadata_fixup_field(in);
+       if (fixup != NULL)
+               in = fixup;
        rc = snprintf(RTE_PTR_ADD(field, count), size, "%s %s;", datatype, in);
+       free(fixup);
        if (rc <= 0 || (size_t)rc >= size) {
                RTE_PER_LCORE(trace_point_sz) = 0;
                trace_crit("CTF field is too long");

diff --git a/lib/librte_eal/common/eal_common_trace_ctf.c b/lib/librte_eal/common/eal_common_trace_ctf.c
index 9dc91df..174cdac 100644 (file)
--- a/lib/librte_eal/common/eal_common_trace_ctf.c
+++ b/lib/librte_eal/common/eal_common_trace_ctf.c
@@ -220,131 +220,12 @@ meta_stream_emit(char **meta, int *offset)
        return meta_copy(meta, offset, str, rc);
 }
 
-static void
-string_fixed_replace(char *input, const char *search, const char *replace)
-{
-       char *found;
-       size_t len;
-
-       found = strstr(input, search);
-       if (found == NULL)
-               return;
-
-       if (strlen(found) != strlen(search))
-               return;
-
-       len = strlen(replace);
-       memcpy(found, replace, len);
-       found[len] = '\0';
-}
-
-static void
-ctf_fixup_align(char *str)
-{
-       string_fixed_replace(str, "align", "_align");
-}
-
-static void
-ctf_fixup_arrow_deref(char *str)
-{
-       const char *replace = "_";
-       const char *search = "->";
-       char *found;
-       size_t len;
-
-       found = strstr(str, search);
-       if (found == NULL)
-               return;
-
-       do {
-               memcpy(found, replace, strlen(replace));
-               len = strlen(found + 2);
-               memcpy(found + 1, found + 2, len);
-               found[len + 1] = '\0';
-               found = strstr(str, search);
-       } while (found != NULL);
-}
-
-static void
-ctf_fixup_dot_deref(char *str)
-{
-       const char *replace = "_";
-       const char *search = ".";
-       char *found;
-       size_t len;
-
-       found = strstr(str, search);
-       if (found == NULL)
-               return;
-
-       len = strlen(replace);
-       do {
-               memcpy(found, replace, len);
-               found = strstr(str, search);
-       } while (found != NULL);
-}
-
-static void
-ctf_fixup_event(char *str)
-{
-       string_fixed_replace(str, "event", "_event");
-}
-
-static int
-ctf_fixup_keyword(char *str)
-{
-       char dup_str[TRACE_CTF_FIELD_SIZE];
-       char input[TRACE_CTF_FIELD_SIZE];
-       const char *delim = ";";
-       char *from;
-       int len;
-
-       if (str == NULL)
-               return 0;
-
-       len = strlen(str);
-       if (len >= TRACE_CTF_FIELD_SIZE) {
-               trace_err("ctf_field reached its maximum limit");
-               return -EMSGSIZE;
-       }
-
-       /* Create duplicate string */
-       strcpy(dup_str, str);
-
-       len = 0;
-       from = strtok(dup_str, delim);
-       while (from != NULL) {
-               strcpy(input, from);
-               ctf_fixup_align(input);
-               ctf_fixup_dot_deref(input);
-               ctf_fixup_arrow_deref(input);
-               ctf_fixup_event(input);
-
-               strcpy(&input[strlen(input)], delim);
-               if ((len + strlen(input)) >= TRACE_CTF_FIELD_SIZE) {
-                       trace_err("ctf_field reached its maximum limit");
-                       return -EMSGSIZE;
-               }
-
-               strcpy(str + len, input);
-               len += strlen(input);
-               from = strtok(NULL, delim);
-       }
-
-       return 0;
-}
-
 static int
 meta_event_emit(char **meta, int *offset, struct trace_point *tp)
 {
        char *str = NULL;
        int rc;
 
-       /* Fixup ctf field string in case it using reserved ctf keywords */
-       rc = ctf_fixup_keyword(tp->ctf_field);
-       if (rc)
-               return rc;
-
        rc = metadata_printf(&str,
                "event {\n"
                "    id = %d;\n"
@@ -491,3 +372,43 @@ rte_trace_metadata_dump(FILE *f)
        rc = fprintf(f, "%s", ctf_meta);
        return rc < 0 ? rc : 0;
 }
+
+char *trace_metadata_fixup_field(const char *field)
+{
+       const char *ctf_reserved_words[] = {
+               "align",
+               "event",
+       };
+       unsigned int i;
+       char *out;
+       char *p;
+
+       /* reserved keywords */
+       for (i = 0; i < RTE_DIM(ctf_reserved_words); i++) {
+               if (strcmp(field, ctf_reserved_words[i]) != 0)
+                       continue;
+               if (asprintf(&out, "_%s", ctf_reserved_words[i]) == -1)
+                       out = NULL;
+               return out;
+       }
+
+       /* nothing to replace, return early */
+       if (strstr(field, ".") == NULL && strstr(field, "->") == NULL)
+               return NULL;
+
+       out = strdup(field);
+       if (out == NULL)
+               return NULL;
+       p = out;
+       while ((p = strstr(p, ".")) != NULL) {
+               p[0] = '_';
+               p++;
+       }
+       p = out;
+       while ((p = strstr(p, "->")) != NULL) {
+               p[0] = '_';
+               p++;
+               memmove(p, p + 1, strlen(p));
+       }
+       return out;
+}

diff --git a/lib/librte_eal/common/eal_trace.h b/lib/librte_eal/common/eal_trace.h
index 438c2b7..8a3f6c5 100644 (file)
--- a/lib/librte_eal/common/eal_trace.h
+++ b/lib/librte_eal/common/eal_trace.h
@@ -104,6 +104,7 @@ bool trace_has_duplicate_entry(void);
 void trace_uuid_generate(void);
 int trace_metadata_create(void);
 void trace_metadata_destroy(void);
+char *trace_metadata_fixup_field(const char *field);
 int trace_mkdir(void);
 int trace_epoch_time_save(void);
 void trace_mem_free(void);