Fix: app contexts: do not leak app context name, event field, context field
[lttng-ust.git] / liblttng-ust / lttng-context.c
index 8ed9bbd4f1db15b13d1d56daaeacbdddc5921b8c..0aaae755cc35b324b2a77a083306acea890010cc 100644 (file)
@@ -17,6 +17,7 @@
 #include <stddef.h>
 #include <string.h>
 #include <assert.h>
+#include <limits.h>
 #include "tracepoint-internal.h"
 
 #include "context-internal.h"
@@ -31,6 +32,8 @@ int lttng_find_context(struct lttng_ust_ctx *ctx, const char *name)
        unsigned int i;
        const char *subname;
 
+       if (!ctx)
+               return 0;
        if (strncmp(name, "$ctx.", strlen("$ctx.")) == 0) {
                subname = name + strlen("$ctx.");
        } else {
@@ -38,9 +41,9 @@ int lttng_find_context(struct lttng_ust_ctx *ctx, const char *name)
        }
        for (i = 0; i < ctx->nr_fields; i++) {
                /* Skip allocated (but non-initialized) contexts */
-               if (!ctx->fields[i]->event_field->name)
+               if (!ctx->fields[i].event_field->name)
                        continue;
-               if (!strcmp(ctx->fields[i]->event_field->name, subname))
+               if (!strcmp(ctx->fields[i].event_field->name, subname))
                        return 1;
        }
        return 0;
@@ -60,9 +63,9 @@ int lttng_get_context_index(struct lttng_ust_ctx *ctx, const char *name)
        }
        for (i = 0; i < ctx->nr_fields; i++) {
                /* Skip allocated (but non-initialized) contexts */
-               if (!ctx->fields[i]->event_field->name)
+               if (!ctx->fields[i].event_field->name)
                        continue;
-               if (!strcmp(ctx->fields[i]->event_field->name, subname))
+               if (!strcmp(ctx->fields[i].event_field->name, subname))
                        return i;
        }
        return -1;
@@ -74,9 +77,9 @@ static int lttng_find_context_provider(struct lttng_ust_ctx *ctx, const char *na
 
        for (i = 0; i < ctx->nr_fields; i++) {
                /* Skip allocated (but non-initialized) contexts */
-               if (!ctx->fields[i]->event_field->name)
+               if (!ctx->fields[i].event_field->name)
                        continue;
-               if (!strncmp(ctx->fields[i]->event_field->name, name,
+               if (!strncmp(ctx->fields[i].event_field->name, name,
                                strlen(name)))
                        return 1;
        }
@@ -85,10 +88,10 @@ static int lttng_find_context_provider(struct lttng_ust_ctx *ctx, const char *na
 
 /*
  * Note: as we append context information, the pointer location may change.
- * lttng_add_context leaves the new last context initialized to NULL.
+ * lttng_ust_context_add_field leaves the new last context initialized to NULL.
  */
 static
-int lttng_add_context(struct lttng_ust_ctx **ctx_p)
+int lttng_ust_context_add_field(struct lttng_ust_ctx **ctx_p)
 {
        struct lttng_ust_ctx *ctx;
 
@@ -96,18 +99,17 @@ int lttng_add_context(struct lttng_ust_ctx **ctx_p)
                *ctx_p = zmalloc(sizeof(struct lttng_ust_ctx));
                if (!*ctx_p)
                        return -ENOMEM;
-               (*ctx_p)->struct_size = sizeof(struct lttng_ust_ctx);
                (*ctx_p)->largest_align = 1;
        }
        ctx = *ctx_p;
        if (ctx->nr_fields + 1 > ctx->allocated_fields) {
-               struct lttng_ust_ctx_field **new_fields;
+               struct lttng_ust_ctx_field *new_fields;
 
                ctx->allocated_fields = max_t(size_t, 1, 2 * ctx->allocated_fields);
                new_fields = zmalloc(ctx->allocated_fields * sizeof(*new_fields));
                if (!new_fields)
                        return -ENOMEM;
-               /* Copy pointers */
+               /* Copy elements */
                if (ctx->fields)
                        memcpy(new_fields, ctx->fields, sizeof(*ctx->fields) * ctx->nr_fields);
                free(ctx->fields);
@@ -117,68 +119,90 @@ int lttng_add_context(struct lttng_ust_ctx **ctx_p)
        return 0;
 }
 
-struct lttng_ust_ctx_field *lttng_append_context(struct lttng_ust_ctx **ctx_p)
+static size_t get_type_max_align(const struct lttng_ust_type_common *type)
 {
-       struct lttng_ust_ctx_field *field;
-       int ret;
+       switch (type->type) {
+       case lttng_ust_type_integer:
+               return lttng_ust_get_type_integer(type)->alignment;
+       case lttng_ust_type_string:
+               return CHAR_BIT;
+       case lttng_ust_type_dynamic:
+               return 0;
+       case lttng_ust_type_enum:
+               return get_type_max_align(lttng_ust_get_type_enum(type)->container_type);
+       case lttng_ust_type_array:
+               return max_t(size_t, get_type_max_align(lttng_ust_get_type_array(type)->elem_type),
+                               lttng_ust_get_type_array(type)->alignment);
+       case lttng_ust_type_sequence:
+               return max_t(size_t, get_type_max_align(lttng_ust_get_type_sequence(type)->elem_type),
+                               lttng_ust_get_type_sequence(type)->alignment);
+       case lttng_ust_type_struct:
+       {
+               unsigned int i;
+               size_t field_align = 0;
+               const struct lttng_ust_type_struct *struct_type = lttng_ust_get_type_struct(type);
+
+               for (i = 0; i < struct_type->nr_fields; i++) {
+                       field_align = max_t(size_t,
+                               get_type_max_align(struct_type->fields[i]->type),
+                               field_align);
+               }
+               return field_align;
+       }
+       default:
+               WARN_ON_ONCE(1);
+               return 0;
+       }
+}
 
-       field = zmalloc(sizeof(struct lttng_ust_ctx_field));
-       if (!field)
-               goto error_alloc_field;
-       field->struct_size = sizeof(struct lttng_ust_ctx_field);
-       field->event_field = zmalloc(sizeof(struct lttng_ust_event_field));
-       if (!field->event_field)
-               goto error_alloc_event_field;
-       field->event_field->struct_size = sizeof(struct lttng_ust_event_field);
+/*
+ * lttng_context_update() should be called at least once between context
+ * modification and trace start.
+ */
+static
+void lttng_context_update(struct lttng_ust_ctx *ctx)
+{
+       int i;
+       size_t largest_align = 8;       /* in bits */
 
-       ret = lttng_add_context(ctx_p);
-       if (ret)
-               goto error_add_context;
-       (*ctx_p)->fields[(*ctx_p)->nr_fields - 1] = field;
-       return field;
+       for (i = 0; i < ctx->nr_fields; i++) {
+               size_t field_align = 8;
 
-error_add_context:
-       free(field->event_field);
-error_alloc_event_field:
-       free(field);
-error_alloc_field:
-       return NULL;
+               field_align = get_type_max_align(ctx->fields[i].event_field->type);
+               largest_align = max_t(size_t, largest_align, field_align);
+       }
+       ctx->largest_align = largest_align >> 3;        /* bits to bytes */
 }
 
-/*
- * Takes ownership of @f on success.
- */
-int lttng_context_add_rcu(struct lttng_ust_ctx **ctx_p,
-               struct lttng_ust_ctx_field *f)
+int lttng_ust_context_append_rcu(struct lttng_ust_ctx **ctx_p,
+               const struct lttng_ust_ctx_field *f)
 {
        struct lttng_ust_ctx *old_ctx = *ctx_p, *new_ctx = NULL;
-       struct lttng_ust_ctx_field **new_fields = NULL;
+       struct lttng_ust_ctx_field *new_fields = NULL;
        int ret;
 
        if (old_ctx) {
                new_ctx = zmalloc(sizeof(struct lttng_ust_ctx));
                if (!new_ctx)
                        return -ENOMEM;
-               new_ctx->struct_size = sizeof(struct lttng_ust_ctx);
                *new_ctx = *old_ctx;
                new_fields = zmalloc(new_ctx->allocated_fields * sizeof(*new_fields));
                if (!new_fields) {
                        free(new_ctx);
                        return -ENOMEM;
                }
-               /* Copy pointers */
+               /* Copy elements */
                memcpy(new_fields, old_ctx->fields,
                                sizeof(*old_ctx->fields) * old_ctx->nr_fields);
                new_ctx->fields = new_fields;
        }
-       ret = lttng_add_context(&new_ctx);
+       ret = lttng_ust_context_add_field(&new_ctx);
        if (ret) {
                free(new_fields);
                free(new_ctx);
                return ret;
        }
-       /* Taking ownership of f. */
-       (*ctx_p)->fields[(*ctx_p)->nr_fields - 1] = f;
+       new_ctx->fields[new_ctx->nr_fields - 1] = *f;
        lttng_context_update(new_ctx);
        lttng_ust_rcu_assign_pointer(*ctx_p, new_ctx);
        lttng_ust_urcu_synchronize_rcu();
@@ -189,96 +213,17 @@ int lttng_context_add_rcu(struct lttng_ust_ctx **ctx_p,
        return 0;
 }
 
-/*
- * lttng_context_update() should be called at least once between context
- * modification and trace start.
- */
-void lttng_context_update(struct lttng_ust_ctx *ctx)
+int lttng_ust_context_append(struct lttng_ust_ctx **ctx_p,
+               const struct lttng_ust_ctx_field *f)
 {
-       int i;
-       size_t largest_align = 8;       /* in bits */
-
-       for (i = 0; i < ctx->nr_fields; i++) {
-               struct lttng_type *type;
-               size_t field_align = 8;
-
-               type = &ctx->fields[i]->event_field->type;
-               switch (type->atype) {
-               case atype_integer:
-                       field_align = type->u.integer.alignment;
-                       break;
-               case atype_array_nestable:
-               {
-                       const struct lttng_type *nested_type;
-
-                       nested_type = type->u.array_nestable.elem_type;
-                       switch (nested_type->atype) {
-                       case atype_integer:
-                               field_align = nested_type->u.integer.alignment;
-                               break;
-                       case atype_string:
-                               break;
-
-                       case atype_array_nestable:
-                       case atype_sequence_nestable:
-                       default:
-                               WARN_ON_ONCE(1);
-                               break;
-                       }
-                       field_align = max_t(size_t, field_align,
-                                       type->u.array_nestable.alignment);
-                       break;
-               }
-               case atype_sequence_nestable:
-               {
-                       const struct lttng_type *nested_type;
-
-                       nested_type = type->u.sequence_nestable.elem_type;
-                       switch (nested_type->atype) {
-                       case atype_integer:
-                               field_align = nested_type->u.integer.alignment;
-                               break;
-
-                       case atype_string:
-                               break;
-
-                       case atype_array_nestable:
-                       case atype_sequence_nestable:
-                       default:
-                               WARN_ON_ONCE(1);
-                               break;
-                       }
-                       field_align = max_t(size_t, field_align,
-                                       type->u.sequence_nestable.alignment);
-                       break;
-               }
-               case atype_string:
-                       break;
-               case atype_dynamic:
-                       break;
-               case atype_enum_nestable:
-               default:
-                       WARN_ON_ONCE(1);
-                       break;
-               }
-               largest_align = max_t(size_t, largest_align, field_align);
-       }
-       ctx->largest_align = largest_align >> 3;        /* bits to bytes */
-}
-
-/*
- * Remove last context field.
- */
-void lttng_remove_context_field(struct lttng_ust_ctx **ctx_p,
-                               struct lttng_ust_ctx_field *field)
-{
-       struct lttng_ust_ctx *ctx;
+       int ret;
 
-       ctx = *ctx_p;
-       ctx->nr_fields--;
-       assert(ctx->fields[ctx->nr_fields] == field);
-       assert(field->field_name == NULL);
-       ctx->fields[ctx->nr_fields] = NULL;
+       ret = lttng_ust_context_add_field(ctx_p);
+       if (ret)
+               return ret;
+       (*ctx_p)->fields[(*ctx_p)->nr_fields - 1] = *f;
+       lttng_context_update(*ctx_p);
+       return 0;
 }
 
 void lttng_destroy_context(struct lttng_ust_ctx *ctx)
@@ -288,11 +233,8 @@ void lttng_destroy_context(struct lttng_ust_ctx *ctx)
        if (!ctx)
                return;
        for (i = 0; i < ctx->nr_fields; i++) {
-               if (ctx->fields[i]->destroy)
-                       ctx->fields[i]->destroy(ctx->fields[i]);
-               free(ctx->fields[i]->field_name);
-               free(ctx->fields[i]->event_field);
-               free(ctx->fields[i]);
+               if (ctx->fields[i].destroy)
+                       ctx->fields[i].destroy(&ctx->fields[i]);
        }
        free(ctx->fields);
        free(ctx);
@@ -312,16 +254,15 @@ void lttng_destroy_context(struct lttng_ust_ctx *ctx)
  */
 int lttng_ust_context_set_provider_rcu(struct lttng_ust_ctx **_ctx,
                const char *name,
-               size_t (*get_size)(struct lttng_ust_ctx_field *field, size_t offset),
-               void (*record)(struct lttng_ust_ctx_field *field,
-                       struct lttng_ust_lib_ring_buffer_ctx *ctx,
-                       struct lttng_channel *chan),
-               void (*get_value)(struct lttng_ust_ctx_field *field,
-                       struct lttng_ust_ctx_value *value))
+               size_t (*get_size)(void *priv, size_t offset),
+               void (*record)(void *priv, struct lttng_ust_lib_ring_buffer_ctx *ctx,
+                       struct lttng_ust_channel_buffer *chan),
+               void (*get_value)(void *priv, struct lttng_ust_ctx_value *value),
+               void *priv)
 {
        int i, ret;
        struct lttng_ust_ctx *ctx = *_ctx, *new_ctx;
-       struct lttng_ust_ctx_field **new_fields;
+       struct lttng_ust_ctx_field *new_fields;
 
        if (!ctx || !lttng_find_context_provider(ctx, name))
                return 0;
@@ -331,23 +272,23 @@ int lttng_ust_context_set_provider_rcu(struct lttng_ust_ctx **_ctx,
        new_ctx = zmalloc(sizeof(*new_ctx));
        if (!new_ctx)
                return -ENOMEM;
-       new_ctx->struct_size = sizeof(*new_ctx);
        *new_ctx = *ctx;
        new_fields = zmalloc(sizeof(*new_fields) * ctx->allocated_fields);
        if (!new_fields) {
                ret = -ENOMEM;
                goto field_error;
        }
-       /* Copy pointers */
+       /* Copy elements */
        memcpy(new_fields, ctx->fields,
                sizeof(*new_fields) * ctx->allocated_fields);
        for (i = 0; i < ctx->nr_fields; i++) {
-               if (strncmp(new_fields[i]->event_field->name,
+               if (strncmp(new_fields[i].event_field->name,
                                name, strlen(name)) != 0)
                        continue;
-               new_fields[i]->get_size = get_size;
-               new_fields[i]->record = record;
-               new_fields[i]->get_value = get_value;
+               new_fields[i].get_size = get_size;
+               new_fields[i].record = record;
+               new_fields[i].get_value = get_value;
+               new_fields[i].priv = priv;
        }
        new_ctx->fields = new_fields;
        lttng_ust_rcu_assign_pointer(*_ctx, new_ctx);
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