+++ /dev/null
-/*
- * SPDX-License-Identifier: LGPL-2.1-only
- *
- * Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
- *
- * LTTng UST trace/channel/event context management.
- */
-
-#define _LGPL_SOURCE
-#include <lttng/ust-events.h>
-#include <lttng/ust-tracer.h>
-#include <ust-context-provider.h>
-#include <lttng/urcu/pointer.h>
-#include <lttng/urcu/urcu-ust.h>
-#include <usterr-signal-safe.h>
-#include <ust-helper.h>
-#include <stddef.h>
-#include <string.h>
-#include <assert.h>
-#include <limits.h>
-#include "tracepoint-internal.h"
-
-#include "context-internal.h"
-
-/*
- * The filter implementation requires that two consecutive "get" for the
- * same context performed by the same thread return the same result.
- */
-
-int lttng_find_context(struct lttng_ust_ctx *ctx, const char *name)
-{
- unsigned int i;
- const char *subname;
-
- if (strncmp(name, "$ctx.", strlen("$ctx.")) == 0) {
- subname = name + strlen("$ctx.");
- } else {
- subname = name;
- }
- for (i = 0; i < ctx->nr_fields; i++) {
- /* Skip allocated (but non-initialized) contexts */
- if (!ctx->fields[i]->event_field->name)
- continue;
- if (!strcmp(ctx->fields[i]->event_field->name, subname))
- return 1;
- }
- return 0;
-}
-
-int lttng_get_context_index(struct lttng_ust_ctx *ctx, const char *name)
-{
- unsigned int i;
- const char *subname;
-
- if (!ctx)
- return -1;
- if (strncmp(name, "$ctx.", strlen("$ctx.")) == 0) {
- subname = name + strlen("$ctx.");
- } else {
- subname = name;
- }
- for (i = 0; i < ctx->nr_fields; i++) {
- /* Skip allocated (but non-initialized) contexts */
- if (!ctx->fields[i]->event_field->name)
- continue;
- if (!strcmp(ctx->fields[i]->event_field->name, subname))
- return i;
- }
- return -1;
-}
-
-static int lttng_find_context_provider(struct lttng_ust_ctx *ctx, const char *name)
-{
- unsigned int i;
-
- for (i = 0; i < ctx->nr_fields; i++) {
- /* Skip allocated (but non-initialized) contexts */
- if (!ctx->fields[i]->event_field->name)
- continue;
- if (!strncmp(ctx->fields[i]->event_field->name, name,
- strlen(name)))
- return 1;
- }
- return 0;
-}
-
-/*
- * Note: as we append context information, the pointer location may change.
- * lttng_add_context leaves the new last context initialized to NULL.
- */
-static
-int lttng_add_context(struct lttng_ust_ctx **ctx_p)
-{
- struct lttng_ust_ctx *ctx;
-
- if (!*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;
-
- 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 */
- if (ctx->fields)
- memcpy(new_fields, ctx->fields, sizeof(*ctx->fields) * ctx->nr_fields);
- free(ctx->fields);
- ctx->fields = new_fields;
- }
- ctx->nr_fields++;
- return 0;
-}
-
-struct lttng_ust_ctx_field *lttng_append_context(struct lttng_ust_ctx **ctx_p)
-{
- struct lttng_ust_ctx_field *field;
- int ret;
-
- 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);
-
- ret = lttng_add_context(ctx_p);
- if (ret)
- goto error_add_context;
- (*ctx_p)->fields[(*ctx_p)->nr_fields - 1] = field;
- return field;
-
-error_add_context:
- free(field->event_field);
-error_alloc_event_field:
- free(field);
-error_alloc_field:
- return NULL;
-}
-
-/*
- * Takes ownership of @f on success.
- */
-int lttng_context_add_rcu(struct lttng_ust_ctx **ctx_p,
- 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;
- 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 */
- 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);
- if (ret) {
- free(new_fields);
- free(new_ctx);
- return ret;
- }
- /* Taking ownership of f. */
- (*ctx_p)->fields[(*ctx_p)->nr_fields - 1] = f;
- lttng_context_update(new_ctx);
- lttng_ust_rcu_assign_pointer(*ctx_p, new_ctx);
- lttng_ust_urcu_synchronize_rcu();
- if (old_ctx) {
- free(old_ctx->fields);
- free(old_ctx);
- }
- return 0;
-}
-
-static size_t get_type_max_align(struct lttng_ust_type_common *type)
-{
- 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;
- 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;
- }
-}
-
-/*
- * 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 i;
- size_t largest_align = 8; /* in bits */
-
- for (i = 0; i < ctx->nr_fields; i++) {
- size_t field_align = 8;
-
- 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 */
-}
-
-/*
- * 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;
-
- ctx = *ctx_p;
- ctx->nr_fields--;
- assert(ctx->fields[ctx->nr_fields] == field);
- lttng_ust_destroy_type(field->event_field->type);
- free((char *) field->event_field->name);
- free(field->event_field);
- free(field);
- ctx->fields[ctx->nr_fields] = NULL;
-}
-
-void lttng_destroy_context(struct lttng_ust_ctx *ctx)
-{
- int i;
-
- if (!ctx)
- return;
- for (i = 0; i < ctx->nr_fields; i++) {
- if (ctx->fields[i]->destroy)
- ctx->fields[i]->destroy(ctx->fields[i]);
- lttng_ust_destroy_type(ctx->fields[i]->event_field->type);
- free((char *) ctx->fields[i]->event_field->name);
- free(ctx->fields[i]->event_field);
- free(ctx->fields[i]);
- }
- free(ctx->fields);
- free(ctx);
-}
-
-/*
- * Can be safely performed concurrently with tracing using the struct
- * lttng_ctx. Using RCU update. Needs to match RCU read-side handling of
- * contexts.
- *
- * This does not allow adding, removing, or changing typing of the
- * contexts, since this needs to stay invariant for metadata. However,
- * it allows updating the handlers associated with all contexts matching
- * a provider (by name) while tracing is using it, in a way that ensures
- * a single RCU read-side critical section see either all old, or all
- * new handlers.
- */
-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_ust_channel_buffer *chan),
- void (*get_value)(struct lttng_ust_ctx_field *field,
- struct lttng_ust_ctx_value *value))
-{
- int i, ret;
- struct lttng_ust_ctx *ctx = *_ctx, *new_ctx;
- struct lttng_ust_ctx_field **new_fields;
-
- if (!ctx || !lttng_find_context_provider(ctx, name))
- return 0;
- /*
- * We have at least one instance of context for the provider.
- */
- 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 */
- 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,
- 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_ctx->fields = new_fields;
- lttng_ust_rcu_assign_pointer(*_ctx, new_ctx);
- lttng_ust_urcu_synchronize_rcu();
- free(ctx->fields);
- free(ctx);
- return 0;
-
-field_error:
- free(new_ctx);
- return ret;
-}
-
-int lttng_context_init_all(struct lttng_ust_ctx **ctx)
-{
- int ret;
-
- ret = lttng_add_pthread_id_to_ctx(ctx);
- if (ret) {
- WARN("Cannot add context lttng_add_pthread_id_to_ctx");
- goto error;
- }
- ret = lttng_add_vtid_to_ctx(ctx);
- if (ret) {
- WARN("Cannot add context lttng_add_vtid_to_ctx");
- goto error;
- }
- ret = lttng_add_vpid_to_ctx(ctx);
- if (ret) {
- WARN("Cannot add context lttng_add_vpid_to_ctx");
- goto error;
- }
- ret = lttng_add_procname_to_ctx(ctx);
- if (ret) {
- WARN("Cannot add context lttng_add_procname_to_ctx");
- goto error;
- }
- ret = lttng_add_cpu_id_to_ctx(ctx);
- if (ret) {
- WARN("Cannot add context lttng_add_cpu_id_to_ctx");
- goto error;
- }
- ret = lttng_add_cgroup_ns_to_ctx(ctx);
- if (ret) {
- WARN("Cannot add context lttng_add_cgroup_ns_to_ctx");
- goto error;
- }
- ret = lttng_add_ipc_ns_to_ctx(ctx);
- if (ret) {
- WARN("Cannot add context lttng_add_ipc_ns_to_ctx");
- goto error;
- }
- ret = lttng_add_mnt_ns_to_ctx(ctx);
- if (ret) {
- WARN("Cannot add context lttng_add_mnt_ns_to_ctx");
- goto error;
- }
- ret = lttng_add_net_ns_to_ctx(ctx);
- if (ret) {
- WARN("Cannot add context lttng_add_net_ns_to_ctx");
- goto error;
- }
- ret = lttng_add_pid_ns_to_ctx(ctx);
- if (ret) {
- WARN("Cannot add context lttng_add_pid_ns_to_ctx");
- goto error;
- }
- ret = lttng_add_time_ns_to_ctx(ctx);
- if (ret) {
- WARN("Cannot add context lttng_add_time_ns_to_ctx");
- goto error;
- }
- ret = lttng_add_user_ns_to_ctx(ctx);
- if (ret) {
- WARN("Cannot add context lttng_add_user_ns_to_ctx");
- goto error;
- }
- ret = lttng_add_uts_ns_to_ctx(ctx);
- if (ret) {
- WARN("Cannot add context lttng_add_uts_ns_to_ctx");
- goto error;
- }
- ret = lttng_add_vuid_to_ctx(ctx);
- if (ret) {
- WARN("Cannot add context lttng_add_vuid_to_ctx");
- goto error;
- }
- ret = lttng_add_veuid_to_ctx(ctx);
- if (ret) {
- WARN("Cannot add context lttng_add_veuid_to_ctx");
- goto error;
- }
- ret = lttng_add_vsuid_to_ctx(ctx);
- if (ret) {
- WARN("Cannot add context lttng_add_vsuid_to_ctx");
- goto error;
- }
- ret = lttng_add_vgid_to_ctx(ctx);
- if (ret) {
- WARN("Cannot add context lttng_add_vgid_to_ctx");
- goto error;
- }
- ret = lttng_add_vegid_to_ctx(ctx);
- if (ret) {
- WARN("Cannot add context lttng_add_vegid_to_ctx");
- goto error;
- }
- ret = lttng_add_vsgid_to_ctx(ctx);
- if (ret) {
- WARN("Cannot add context lttng_add_vsgid_to_ctx");
- goto error;
- }
- lttng_context_update(*ctx);
- return 0;
-
-error:
- lttng_destroy_context(*ctx);
- return ret;
-}
projects / lttng-ust.git / blobdiff