X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;ds=sidebyside;f=lttng-context-callstack.c;h=195990a6e3e1292bebce8277a7b3bdefbd0d5acb;hb=HEAD;hp=e8be78faab37c97c25d4cfbd8a300837d909d581;hpb=2459130397d7e7eecc44a5f06a39d65c78257eef;p=lttng-modules.git diff --git a/lttng-context-callstack.c b/lttng-context-callstack.c deleted file mode 100644 index e8be78fa..00000000 --- a/lttng-context-callstack.c +++ /dev/null @@ -1,193 +0,0 @@ -/* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only) - * - * lttng-context-callstack.c - * - * LTTng callstack event context. - * - * Copyright (C) 2014 Mathieu Desnoyers - * Copyright (C) 2014 Francis Giraldeau - * - * The callstack context can be added to any kernel event. It records - * either the kernel or the userspace callstack, up to a max depth. The - * context is a CTF sequence, such that it uses only the space required - * for the number of callstack entries. - * - * It allocates callstack buffers per-CPU up to 4 interrupt nesting. - * This nesting limit is the same as defined in the ring buffer. It - * therefore uses a fixed amount of memory, proportional to the number - * of CPUs: - * - * size = cpus * nest * depth * sizeof(unsigned long) - * - * Which is 4096 bytes per CPU on 64-bit host and a depth of 128. - * The allocation is done at the initialization to avoid memory - * allocation overhead while tracing, using a shallow stack. - * - * The kernel callstack is recovered using save_stack_trace(), and the - * userspace callstack uses save_stack_trace_user(). They rely on frame - * pointers. These are usually available for the kernel, but the - * compiler option -fomit-frame-pointer frequently used in popular Linux - * distributions may cause the userspace callstack to be unreliable, and - * is a known limitation of this approach. If frame pointers are not - * available, it produces no error, but the callstack will be empty. We - * still provide the feature, because it works well for runtime - * environments having frame pointers. In the future, unwind support - * and/or last branch record may provide a solution to this problem. - * - * The symbol name resolution is left to the trace reader. - */ - -#include -#include -#include -#include -#include -#include -#include "lttng-events.h" -#include -#include -#include "wrapper/vmalloc.h" -#include "lttng-tracer.h" -#include "lttng-endian.h" - -#ifdef CONFIG_ARCH_STACKWALK -#include "lttng-context-callstack-stackwalk-impl.h" -#else -#include "lttng-context-callstack-legacy-impl.h" -#endif - -static -void field_data_free(struct field_data *fdata) -{ - if (!fdata) - return; - free_percpu(fdata->cs_percpu); - kfree(fdata); -} - -static -struct field_data __percpu *field_data_create(enum lttng_cs_ctx_modes mode) -{ - struct lttng_cs __percpu *cs_set; - struct field_data *fdata; - - fdata = kzalloc(sizeof(*fdata), GFP_KERNEL); - if (!fdata) - return NULL; - cs_set = alloc_percpu(struct lttng_cs); - if (!cs_set) - goto error_alloc; - lttng_cs_set_init(cs_set); - fdata->cs_percpu = cs_set; - fdata->mode = mode; - return fdata; - -error_alloc: - field_data_free(fdata); - return NULL; -} - -static -void lttng_callstack_sequence_destroy(struct lttng_ctx_field *field) -{ - struct field_data *fdata = field->priv; - - field_data_free(fdata); -} - -static const struct lttng_type sequence_elem_type = - __type_integer(unsigned long, 0, 0, -1, __BYTE_ORDER, 16, none); - -static -int __lttng_add_callstack_generic(struct lttng_ctx **ctx, - enum lttng_cs_ctx_modes mode) -{ - const char *ctx_name = lttng_cs_ctx_mode_name(mode); - const char *ctx_length_name = lttng_cs_ctx_mode_length_name(mode); - struct lttng_ctx_field *length_field, *sequence_field; - struct lttng_event_field *field; - struct field_data *fdata; - int ret; - - ret = init_type(mode); - if (ret) - return ret; - length_field = lttng_append_context(ctx); - if (!length_field) - return -ENOMEM; - sequence_field = lttng_append_context(ctx); - if (!sequence_field) { - lttng_remove_context_field(ctx, length_field); - return -ENOMEM; - } - if (lttng_find_context(*ctx, ctx_name)) { - ret = -EEXIST; - goto error_find; - } - fdata = field_data_create(mode); - if (!fdata) { - ret = -ENOMEM; - goto error_create; - } - - field = &length_field->event_field; - field->name = ctx_length_name; - field->type.atype = atype_integer; - field->type.u.integer.size = sizeof(unsigned int) * CHAR_BIT; - field->type.u.integer.alignment = lttng_alignof(unsigned int) * CHAR_BIT; - field->type.u.integer.signedness = lttng_is_signed_type(unsigned int); - field->type.u.integer.reverse_byte_order = 0; - field->type.u.integer.base = 10; - field->type.u.integer.encoding = lttng_encode_none; - length_field->get_size_arg = lttng_callstack_length_get_size; - length_field->record = lttng_callstack_length_record; - - field = &sequence_field->event_field; - field->name = ctx_name; - field->type.atype = atype_sequence_nestable; - field->type.u.sequence_nestable.elem_type = &sequence_elem_type; - field->type.u.sequence_nestable.alignment = 0; - sequence_field->get_size_arg = lttng_callstack_sequence_get_size; - sequence_field->record = lttng_callstack_sequence_record; - sequence_field->priv = fdata; - sequence_field->destroy = lttng_callstack_sequence_destroy; - - wrapper_vmalloc_sync_mappings(); - return 0; - -error_create: - field_data_free(fdata); -error_find: - lttng_remove_context_field(ctx, sequence_field); - lttng_remove_context_field(ctx, length_field); - return ret; -} - -/** - * lttng_add_callstack_to_ctx - add callstack event context - * - * @ctx: the lttng_ctx pointer to initialize - * @type: the context type - * - * Supported callstack type supported: - * LTTNG_KERNEL_CONTEXT_CALLSTACK_KERNEL - * Records the callstack of the kernel - * LTTNG_KERNEL_CONTEXT_CALLSTACK_USER - * Records the callstack of the userspace program (from the kernel) - * - * Return 0 for success, or error code. - */ -int lttng_add_callstack_to_ctx(struct lttng_ctx **ctx, int type) -{ - switch (type) { - case LTTNG_KERNEL_CONTEXT_CALLSTACK_KERNEL: - return __lttng_add_callstack_generic(ctx, CALLSTACK_KERNEL); -#ifdef CONFIG_X86 - case LTTNG_KERNEL_CONTEXT_CALLSTACK_USER: - return __lttng_add_callstack_generic(ctx, CALLSTACK_USER); -#endif - default: - return -EINVAL; - } -} -EXPORT_SYMBOL_GPL(lttng_add_callstack_to_ctx);