Decouple `struct lttng_event` from filter code

The filter infrastructure will be used by event notifiers and decoupling
this will allow for massive code reuse.

Of all `struct lttng_event`'s fields, filter code needs:
	1. The `const struct lttng_event_desc *desc` field,
	2. The `struct cds_list_head bytecode_runtime_head` list.

These fields are used to do the tracepoint field relocation
(`apply_field_reloc()` and `specialize_event_payload_lookup()`).

Considering that only these two field are needed, we can pass them
directly to these functions.

Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: If569b7d315700660aa84241d112668f2451b715a

diff --git a/include/lttng/events.h b/include/lttng/events.h
index 69aca1e078579b2c86fc7666c834a905da237ce3..833a344a72d5f5f5367ba109b6da36ee7599d02b 100644 (file)
--- a/include/lttng/events.h
+++ b/include/lttng/events.h
@@ -255,7 +255,7 @@ struct lttng_bytecode_runtime {
                        const char *filter_stack_data);
        int link_failed;
        struct list_head node;  /* list of bytecode runtime in event */
-       struct lttng_event *event;
+       struct lttng_ctx *ctx;
 };
 
 /*
@@ -711,8 +711,11 @@ static inline long lttng_channel_syscall_mask(struct lttng_channel *channel,
 void lttng_filter_sync_state(struct lttng_bytecode_runtime *runtime);
 int lttng_event_enabler_attach_bytecode(struct lttng_event_enabler *event_enabler,
                struct lttng_kernel_filter_bytecode __user *bytecode);
-void lttng_event_enabler_link_bytecode(struct lttng_event *event,
-               struct lttng_event_enabler *event_enabler);
+
+void lttng_enabler_link_bytecode(const struct lttng_event_desc *event_desc,
+               struct lttng_ctx *ctx,
+               struct list_head *bytecode_runtime_head,
+               struct lttng_enabler *enabler);
 
 int lttng_probes_init(void);
 

diff --git a/include/lttng/filter.h b/include/lttng/filter.h
index e999a0572f2797bcda2eb59a2ef18f6e0cadf085..a9477870491d5bace0ee03eadb7be31a9bedd3bc 100644 (file)
--- a/include/lttng/filter.h
+++ b/include/lttng/filter.h
@@ -235,7 +235,7 @@ struct estack {
 const char *lttng_filter_print_op(enum filter_op op);
 
 int lttng_filter_validate_bytecode(struct bytecode_runtime *bytecode);
-int lttng_filter_specialize_bytecode(struct lttng_event *event,
+int lttng_filter_specialize_bytecode(const struct lttng_event_desc *event_desc,
                struct bytecode_runtime *bytecode);
 
 uint64_t lttng_filter_false(void *filter_data,

diff --git a/src/lttng-events.c b/src/lttng-events.c
index cd0c5eb7e89348ed74f98c7af1b05764adc83d53..34e5fe9d98e657aaba9de8cac0f250614b6eaff0 100644 (file)
--- a/src/lttng-events.c
+++ b/src/lttng-events.c
@@ -1484,7 +1484,10 @@ int lttng_event_enabler_ref_events(struct lttng_event_enabler *event_enabler)
                /*
                 * Link filter bytecodes if not linked yet.
                 */
-               lttng_event_enabler_link_bytecode(event, event_enabler);
+               lttng_enabler_link_bytecode(event->desc,
+                       lttng_static_ctx,
+                       &event->bytecode_runtime_head,
+                       lttng_event_enabler_as_enabler(event_enabler));
 
                /* TODO: merge event context. */
        }

diff --git a/src/lttng-filter-specialize.c b/src/lttng-filter-specialize.c
index 1d7f29a4c7ca15bcce9142185db53b52deb6b019..c7718ec726778fcf75b48e1d09314885f53265b5 100644 (file)
--- a/src/lttng-filter-specialize.c
+++ b/src/lttng-filter-specialize.c
@@ -297,7 +297,8 @@ end:
        return ret;
 }
 
-static int specialize_context_lookup_name(struct bytecode_runtime *bytecode,
+static int specialize_context_lookup_name(struct lttng_ctx *ctx,
+               struct bytecode_runtime *bytecode,
                struct load_op *insn)
 {
        uint16_t offset;
@@ -305,7 +306,7 @@ static int specialize_context_lookup_name(struct bytecode_runtime *bytecode,
 
        offset = ((struct get_symbol *) insn->data)->offset;
        name = bytecode->p.bc->bc.data + bytecode->p.bc->bc.reloc_offset + offset;
-       return lttng_get_context_index(lttng_static_ctx, name);
+       return lttng_get_context_index(ctx, name);
 }
 
 static int specialize_load_object(const struct lttng_event_field *field,
@@ -383,7 +384,8 @@ static int specialize_load_object(const struct lttng_event_field *field,
        return 0;
 }
 
-static int specialize_context_lookup(struct bytecode_runtime *runtime,
+static int specialize_context_lookup(struct lttng_ctx *ctx,
+               struct bytecode_runtime *runtime,
                struct load_op *insn,
                struct vstack_load *load)
 {
@@ -393,7 +395,7 @@ static int specialize_context_lookup(struct bytecode_runtime *runtime,
        struct filter_get_index_data gid;
        ssize_t data_offset;
 
-       idx = specialize_context_lookup_name(runtime, insn);
+       idx = specialize_context_lookup_name(ctx, runtime, insn);
        if (idx < 0) {
                return -ENOENT;
        }
@@ -416,14 +418,13 @@ static int specialize_context_lookup(struct bytecode_runtime *runtime,
        return 0;
 }
 
-static int specialize_event_payload_lookup(struct lttng_event *event,
+static int specialize_payload_lookup(const struct lttng_event_desc *event_desc,
                struct bytecode_runtime *runtime,
                struct load_op *insn,
                struct vstack_load *load)
 {
        const char *name;
        uint16_t offset;
-       const struct lttng_event_desc *desc = event->desc;
        unsigned int i, nr_fields;
        bool found = false;
        uint32_t field_offset = 0;
@@ -432,11 +433,11 @@ static int specialize_event_payload_lookup(struct lttng_event *event,
        struct filter_get_index_data gid;
        ssize_t data_offset;
 
-       nr_fields = desc->nr_fields;
+       nr_fields = event_desc->nr_fields;
        offset = ((struct get_symbol *) insn->data)->offset;
        name = runtime->p.bc->bc.data + runtime->p.bc->bc.reloc_offset + offset;
        for (i = 0; i < nr_fields; i++) {
-               field = &desc->fields[i];
+               field = &event_desc->fields[i];
                if (field->nofilter) {
                        continue;
                }
@@ -489,13 +490,14 @@ end:
        return ret;
 }
 
-int lttng_filter_specialize_bytecode(struct lttng_event *event,
+int lttng_filter_specialize_bytecode(const struct lttng_event_desc *event_desc,
                struct bytecode_runtime *bytecode)
 {
        void *pc, *next_pc, *start_pc;
        int ret = -EINVAL;
        struct vstack _stack;
        struct vstack *stack = &_stack;
+       struct lttng_ctx *ctx = bytecode->p.ctx;
 
        vstack_init(stack);
 
@@ -1150,7 +1152,7 @@ int lttng_filter_specialize_bytecode(struct lttng_event *event,
                                goto end;
                        case LOAD_ROOT_CONTEXT:
                                /* Lookup context field. */
-                               ret = specialize_context_lookup(bytecode, insn,
+                               ret = specialize_context_lookup(ctx, bytecode, insn,
                                        &vstack_ax(stack)->load);
                                if (ret)
                                        goto end;
@@ -1160,7 +1162,7 @@ int lttng_filter_specialize_bytecode(struct lttng_event *event,
                                goto end;
                        case LOAD_ROOT_PAYLOAD:
                                /* Lookup event payload field. */
-                               ret = specialize_event_payload_lookup(event,
+                               ret = specialize_payload_lookup(event_desc,
                                        bytecode, insn,
                                        &vstack_ax(stack)->load);
                                if (ret)

diff --git a/src/lttng-filter.c b/src/lttng-filter.c
index 0b5e872fdb969ce2071d4e4a16f8e08df4cfb7a5..b33ae9296a6d4142ecc06381fa50af33c67b38b6 100644 (file)
--- a/src/lttng-filter.c
+++ b/src/lttng-filter.c
@@ -167,14 +167,13 @@ const char *lttng_filter_print_op(enum filter_op op)
 }
 
 static
-int apply_field_reloc(struct lttng_event *event,
+int apply_field_reloc(const struct lttng_event_desc *event_desc,
                struct bytecode_runtime *runtime,
                uint32_t runtime_len,
                uint32_t reloc_offset,
                const char *field_name,
                enum filter_op filter_op)
 {
-       const struct lttng_event_desc *desc;
        const struct lttng_event_field *fields, *field = NULL;
        unsigned int nr_fields, i;
        struct load_op *op;
@@ -183,13 +182,12 @@ int apply_field_reloc(struct lttng_event *event,
        dbg_printk("Apply field reloc: %u %s\n", reloc_offset, field_name);
 
        /* Lookup event by name */
-       desc = event->desc;
-       if (!desc)
+       if (!event_desc)
                return -EINVAL;
-       fields = desc->fields;
+       fields = event_desc->fields;
        if (!fields)
                return -EINVAL;
-       nr_fields = desc->nr_fields;
+       nr_fields = event_desc->nr_fields;
        for (i = 0; i < nr_fields; i++) {
                if (fields[i].nofilter)
                        continue;
@@ -274,8 +272,7 @@ int apply_field_reloc(struct lttng_event *event,
 }
 
 static
-int apply_context_reloc(struct lttng_event *event,
-               struct bytecode_runtime *runtime,
+int apply_context_reloc(struct bytecode_runtime *runtime,
                uint32_t runtime_len,
                uint32_t reloc_offset,
                const char *context_name,
@@ -344,7 +341,7 @@ int apply_context_reloc(struct lttng_event *event,
 }
 
 static
-int apply_reloc(struct lttng_event *event,
+int apply_reloc(const struct lttng_event_desc *event_desc,
                struct bytecode_runtime *runtime,
                uint32_t runtime_len,
                uint32_t reloc_offset,
@@ -361,10 +358,10 @@ int apply_reloc(struct lttng_event *event,
        op = (struct load_op *) &runtime->code[reloc_offset];
        switch (op->op) {
        case FILTER_OP_LOAD_FIELD_REF:
-               return apply_field_reloc(event, runtime, runtime_len,
+               return apply_field_reloc(event_desc, runtime, runtime_len,
                        reloc_offset, name, op->op);
        case FILTER_OP_GET_CONTEXT_REF:
-               return apply_context_reloc(event, runtime, runtime_len,
+               return apply_context_reloc(runtime, runtime_len,
                        reloc_offset, name, op->op);
        case FILTER_OP_GET_SYMBOL:
        case FILTER_OP_GET_SYMBOL_FIELD:
@@ -382,12 +379,11 @@ int apply_reloc(struct lttng_event *event,
 
 static
 int bytecode_is_linked(struct lttng_filter_bytecode_node *filter_bytecode,
-               struct lttng_event *event)
+               struct list_head *bytecode_runtime_head)
 {
        struct lttng_bytecode_runtime *bc_runtime;
 
-       list_for_each_entry(bc_runtime,
-                       &event->bytecode_runtime_head, node) {
+       list_for_each_entry(bc_runtime, bytecode_runtime_head, node) {
                if (bc_runtime->bc == filter_bytecode)
                        return 1;
        }
@@ -399,7 +395,8 @@ int bytecode_is_linked(struct lttng_filter_bytecode_node *filter_bytecode,
  * bytecode runtime.
  */
 static
-int _lttng_filter_event_link_bytecode(struct lttng_event *event,
+int _lttng_filter_link_bytecode(const struct lttng_event_desc *event_desc,
+               struct lttng_ctx *ctx,
                struct lttng_filter_bytecode_node *filter_bytecode,
                struct list_head *insert_loc)
 {
@@ -410,7 +407,7 @@ int _lttng_filter_event_link_bytecode(struct lttng_event *event,
        if (!filter_bytecode)
                return 0;
        /* Bytecode already linked */
-       if (bytecode_is_linked(filter_bytecode, event))
+       if (bytecode_is_linked(filter_bytecode, insert_loc))
                return 0;
 
        dbg_printk("Linking...\n");
@@ -423,7 +420,7 @@ int _lttng_filter_event_link_bytecode(struct lttng_event *event,
                goto alloc_error;
        }
        runtime->p.bc = filter_bytecode;
-       runtime->p.event = event;
+       runtime->p.ctx = ctx;
        runtime->len = filter_bytecode->bc.reloc_offset;
        /* copy original bytecode */
        memcpy(runtime->code, filter_bytecode->bc.data, runtime->len);
@@ -439,7 +436,7 @@ int _lttng_filter_event_link_bytecode(struct lttng_event *event,
                const char *name =
                        (const char *) &filter_bytecode->bc.data[offset + sizeof(uint16_t)];
 
-               ret = apply_reloc(event, runtime, runtime->len, reloc_offset, name);
+               ret = apply_reloc(event_desc, runtime, runtime->len, reloc_offset, name);
                if (ret) {
                        goto link_error;
                }
@@ -451,7 +448,7 @@ int _lttng_filter_event_link_bytecode(struct lttng_event *event,
                goto link_error;
        }
        /* Specialize bytecode */
-       ret = lttng_filter_specialize_bytecode(event, runtime);
+       ret = lttng_filter_specialize_bytecode(event_desc, runtime);
        if (ret) {
                goto link_error;
        }
@@ -483,23 +480,24 @@ void lttng_filter_sync_state(struct lttng_bytecode_runtime *runtime)
 /*
  * Link bytecode for all enablers referenced by an event.
  */
-void lttng_event_enabler_link_bytecode(struct lttng_event *event,
-               struct lttng_event_enabler *event_enabler)
+void lttng_enabler_link_bytecode(const struct lttng_event_desc *event_desc,
+               struct lttng_ctx *ctx,
+               struct list_head *bytecode_runtime_head,
+               struct lttng_enabler *enabler)
 {
        struct lttng_filter_bytecode_node *bc;
        struct lttng_bytecode_runtime *runtime;
-       struct lttng_enabler *base_enabler = lttng_event_enabler_as_enabler(event_enabler);
 
        /* Can only be called for events with desc attached */
-       WARN_ON_ONCE(!event->desc);
+       WARN_ON_ONCE(!event_desc);
 
        /* Link each bytecode. */
-       list_for_each_entry(bc, &base_enabler->filter_bytecode_head, node) {
+       list_for_each_entry(bc, &enabler->filter_bytecode_head, node) {
                int found = 0, ret;
                struct list_head *insert_loc;
 
                list_for_each_entry(runtime,
-                               &event->bytecode_runtime_head, node) {
+                               bytecode_runtime_head, node) {
                        if (runtime->bc == bc) {
                                found = 1;
                                break;
@@ -515,7 +513,7 @@ void lttng_event_enabler_link_bytecode(struct lttng_event *event,
                 * insert the new bytecode right after it.
                 */
                list_for_each_entry_reverse(runtime,
-                               &event->bytecode_runtime_head, node) {
+                               bytecode_runtime_head, node) {
                        if (runtime->bc->bc.seqnum <= bc->bc.seqnum) {
                                /* insert here */
                                insert_loc = &runtime->node;
@@ -523,11 +521,11 @@ void lttng_event_enabler_link_bytecode(struct lttng_event *event,
                        }
                }
                /* Add to head to list */
-               insert_loc = &event->bytecode_runtime_head;
+               insert_loc = bytecode_runtime_head;
        add_within:
                dbg_printk("linking bytecode\n");
-               ret = _lttng_filter_event_link_bytecode(event, bc,
-                               insert_loc);
+               ret = _lttng_filter_link_bytecode(event_desc, ctx, bc,
+                       insert_loc);
                if (ret) {
                        dbg_printk("[lttng filter] warning: cannot link event bytecode\n");
                }