+++ /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 <usterr-signal-safe.h>
-#include <helper.h>
-#include <stddef.h>
-#include <string.h>
-#include <assert.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_ctx *ctx, const char *name)
-{
- unsigned int i;
- const char *subname;
-
- if (strncmp(name, "$ctx.", strlen("$ctx.")) == 0) {
- subname = name + strlen("$ctx.");
- } else {
- subname = name;
- }
- for (i = 0; i < ctx->nr_fields; i++) {
- /* Skip allocated (but non-initialized) contexts */
- if (!ctx->fields[i].event_field.name)
- continue;
- if (!strcmp(ctx->fields[i].event_field.name, subname))
- return 1;
- }
- return 0;
-}
-
-int lttng_get_context_index(struct lttng_ctx *ctx, const char *name)
-{
- unsigned int i;
- const char *subname;
-
- if (!ctx)
- return -1;
- if (strncmp(name, "$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_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.
- */
-struct lttng_ctx_field *lttng_append_context(struct lttng_ctx **ctx_p)
-{
- struct lttng_ctx_field *field;
- struct lttng_ctx *ctx;
-
- if (!*ctx_p) {
- *ctx_p = zmalloc(sizeof(struct lttng_ctx));
- if (!*ctx_p)
- return NULL;
- (*ctx_p)->largest_align = 1;
- }
- ctx = *ctx_p;
- if (ctx->nr_fields + 1 > ctx->allocated_fields) {
- struct lttng_ctx_field *new_fields;
-
- ctx->allocated_fields = max_t(size_t, 1, 2 * ctx->allocated_fields);
- new_fields = zmalloc(ctx->allocated_fields * sizeof(struct lttng_ctx_field));
- if (!new_fields)
- return NULL;
- if (ctx->fields)
- memcpy(new_fields, ctx->fields, sizeof(*ctx->fields) * ctx->nr_fields);
- free(ctx->fields);
- ctx->fields = new_fields;
- }
- field = &ctx->fields[ctx->nr_fields];
- ctx->nr_fields++;
- return field;
-}
-
-int lttng_context_add_rcu(struct lttng_ctx **ctx_p,
- const struct lttng_ctx_field *f)
-{
- struct lttng_ctx *old_ctx = *ctx_p, *new_ctx = NULL;
- struct lttng_ctx_field *new_fields = NULL;
- struct lttng_ctx_field *nf;
-
- if (old_ctx) {
- new_ctx = zmalloc(sizeof(struct lttng_ctx));
- if (!new_ctx)
- return -ENOMEM;
- *new_ctx = *old_ctx;
- new_fields = zmalloc(new_ctx->allocated_fields
- * sizeof(struct lttng_ctx_field));
- if (!new_fields) {
- free(new_ctx);
- return -ENOMEM;
- }
- memcpy(new_fields, old_ctx->fields,
- sizeof(*old_ctx->fields) * old_ctx->nr_fields);
- new_ctx->fields = new_fields;
- }
- nf = lttng_append_context(&new_ctx);
- if (!nf) {
- free(new_fields);
- free(new_ctx);
- return -ENOMEM;
- }
- *nf = *f;
- lttng_context_update(new_ctx);
- lttng_ust_rcu_assign_pointer(*ctx_p, new_ctx);
- lttng_ust_synchronize_trace();
- if (old_ctx) {
- free(old_ctx->fields);
- free(old_ctx);
- }
- return 0;
-}
-
-/*
- * lttng_context_update() should be called at least once between context
- * modification and trace start.
- */
-void lttng_context_update(struct lttng_ctx *ctx)
-{
- 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:
- {
- struct lttng_basic_type *btype;
-
- btype = &type->u.legacy.array.elem_type;
- switch (btype->atype) {
- case atype_integer:
- field_align = btype->u.basic.integer.alignment;
- break;
- case atype_string:
- break;
-
- case atype_array:
- case atype_array_nestable:
- case atype_sequence:
- case atype_sequence_nestable:
- default:
- WARN_ON_ONCE(1);
- break;
- }
- 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:
- case atype_array_nestable:
- case atype_sequence:
- 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:
- {
- struct lttng_basic_type *btype;
-
- btype = &type->u.legacy.sequence.length_type;
- switch (btype->atype) {
- case atype_integer:
- field_align = btype->u.basic.integer.alignment;
- break;
-
- case atype_string:
- case atype_array:
- case atype_array_nestable:
- case atype_sequence:
- case atype_sequence_nestable:
- default:
- WARN_ON_ONCE(1);
- break;
- }
-
- btype = &type->u.legacy.sequence.elem_type;
- switch (btype->atype) {
- case atype_integer:
- field_align = max_t(size_t,
- field_align,
- btype->u.basic.integer.alignment);
- break;
-
- case atype_string:
- break;
-
- case atype_array:
- case atype_array_nestable:
- case atype_sequence:
- case atype_sequence_nestable:
- default:
- WARN_ON_ONCE(1);
- break;
- }
- 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:
- case atype_array_nestable:
- case atype_sequence:
- 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:
- 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_ctx **ctx_p,
- struct lttng_ctx_field *field)
-{
- struct lttng_ctx *ctx;
-
- ctx = *ctx_p;
- ctx->nr_fields--;
- assert(&ctx->fields[ctx->nr_fields] == field);
- assert(field->field_name == NULL);
- memset(&ctx->fields[ctx->nr_fields], 0, sizeof(struct lttng_ctx_field));
-}
-
-void lttng_destroy_context(struct lttng_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]);
- free(ctx->fields[i].field_name);
- }
- 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_ctx **_ctx,
- const char *name,
- size_t (*get_size)(struct lttng_ctx_field *field, size_t offset),
- void (*record)(struct lttng_ctx_field *field,
- struct lttng_ust_lib_ring_buffer_ctx *ctx,
- struct lttng_channel *chan),
- void (*get_value)(struct lttng_ctx_field *field,
- struct lttng_ctx_value *value))
-{
- int i, ret;
- struct lttng_ctx *ctx = *_ctx, *new_ctx;
- struct lttng_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 = *ctx;
- new_fields = zmalloc(sizeof(*new_fields) * ctx->allocated_fields);
- if (!new_fields) {
- ret = -ENOMEM;
- goto field_error;
- }
- 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_synchronize_trace();
- free(ctx->fields);
- free(ctx);
- return 0;
-
-field_error:
- free(new_ctx);
- return ret;
-}
-
-int lttng_context_init_all(struct lttng_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