trace: remove size limit on CTF event description

Rework registration so that it uses dynamic allocations and has no size
limit.

Signed-off-by: David Marchand <david.marchand@redhat.com>
Reviewed-by: Jerin Jacob <jerinj@marvell.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 80b458e..bc031ca 100644 (file)
--- a/lib/librte_eal/common/eal_common_trace.c
+++ b/lib/librte_eal/common/eal_common_trace.c
@@ -17,8 +17,7 @@
 
 RTE_DEFINE_PER_LCORE(volatile int, trace_point_sz);
 RTE_DEFINE_PER_LCORE(void *, trace_mem);
-static RTE_DEFINE_PER_LCORE(char, ctf_field[TRACE_CTF_FIELD_SIZE]);
-static RTE_DEFINE_PER_LCORE(int, ctf_count);
+static RTE_DEFINE_PER_LCORE(char *, ctf_field);
 
 static struct trace_point_head tp_list = STAILQ_HEAD_INITIALIZER(tp_list);
 static struct trace trace = { .args = STAILQ_HEAD_INITIALIZER(trace.args), };
@@ -429,32 +428,33 @@ trace_mem_free(void)
 void
 __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 *field;
        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);
+       rc = asprintf(&field, "%s%s %s;",
+               RTE_PER_LCORE(ctf_field) != NULL ?
+                       RTE_PER_LCORE(ctf_field) : "",
+               datatype, in);
+       free(RTE_PER_LCORE(ctf_field));
        free(fixup);
-       if (rc <= 0 || (size_t)rc >= size) {
+       if (rc == -1) {
                RTE_PER_LCORE(trace_point_sz) = 0;
-               trace_crit("CTF field is too long");
+               RTE_PER_LCORE(ctf_field) = NULL;
+               trace_crit("could not allocate CTF field");
                return;
        }
-       RTE_PER_LCORE(ctf_count) += rc;
+       RTE_PER_LCORE(trace_point_sz) += sz;
+       RTE_PER_LCORE(ctf_field) = field;
 }
 
 int
 __rte_trace_point_register(rte_trace_point_t *handle, const char *name,
                void (*register_fn)(void))
 {
-       char *field = RTE_PER_LCORE(ctf_field);
        struct trace_point *tp;
        uint16_t sz;
 
@@ -467,7 +467,6 @@ __rte_trace_point_register(rte_trace_point_t *handle, const char *name,
 
        /* Check the size of the trace point object */
        RTE_PER_LCORE(trace_point_sz) = 0;
-       RTE_PER_LCORE(ctf_count) = 0;
        register_fn();
        if (RTE_PER_LCORE(trace_point_sz) == 0) {
                trace_err("missing rte_trace_emit_header() in register fn");
@@ -505,15 +504,11 @@ __rte_trace_point_register(rte_trace_point_t *handle, const char *name,
                goto free;
        }
 
-       /* Copy the field data for future use */
-       if (rte_strscpy(tp->ctf_field, field, TRACE_CTF_FIELD_SIZE) < 0) {
-               trace_err("CTF field size is too long");
-               rte_errno = E2BIG;
-               goto free;
-       }
-
-       /* Clear field memory for the next event */
-       memset(field, 0, TRACE_CTF_FIELD_SIZE);
+       /* Copy the accumulated fields description and clear it for the next
+        * trace point.
+        */
+       tp->ctf_field = RTE_PER_LCORE(ctf_field);
+       RTE_PER_LCORE(ctf_field) = NULL;
 
        /* Form the trace handle */
        *handle = sz;

diff --git a/lib/librte_eal/common/eal_common_trace_ctf.c b/lib/librte_eal/common/eal_common_trace_ctf.c
index 174cdac..ac1f64d 100644 (file)
--- a/lib/librte_eal/common/eal_common_trace_ctf.c
+++ b/lib/librte_eal/common/eal_common_trace_ctf.c
@@ -233,7 +233,8 @@ meta_event_emit(char **meta, int *offset, struct trace_point *tp)
                "    fields := struct {\n"
                "        %s\n"
                "    };\n"
-               "};\n\n", trace_id_get(tp->handle), tp->name, tp->ctf_field);
+               "};\n\n", trace_id_get(tp->handle), tp->name,
+               tp->ctf_field != NULL ? tp->ctf_field : "");
        return meta_copy(meta, offset, str, rc);
 }
 

diff --git a/lib/librte_eal/common/eal_trace.h b/lib/librte_eal/common/eal_trace.h
index 8a3f6c5..06751eb 100644 (file)
--- a/lib/librte_eal/common/eal_trace.h
+++ b/lib/librte_eal/common/eal_trace.h
@@ -24,7 +24,6 @@
 
 #define TRACE_PREFIX_LEN 12
 #define TRACE_DIR_STR_LEN (sizeof("YYYY-mm-dd-AM-HH-MM-SS") + TRACE_PREFIX_LEN)
-#define TRACE_CTF_FIELD_SIZE 448
 #define TRACE_POINT_NAME_SIZE 64
 #define TRACE_CTF_MAGIC 0xC1FC1FC1
 #define TRACE_MAX_ARGS 32
@@ -33,7 +32,7 @@ struct trace_point {
        STAILQ_ENTRY(trace_point) next;
        rte_trace_point_t *handle;
        char name[TRACE_POINT_NAME_SIZE];
-       char ctf_field[TRACE_CTF_FIELD_SIZE];
+       char *ctf_field;
 };
 
 enum trace_area_e {