From: Julien Desfossez Date: Thu, 23 Aug 2012 20:54:03 +0000 (-0400) Subject: Support the hostname context X-Git-Tag: v2.1.0-rc1~8 X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=975da2c003441a8a16a36947e9500237c197e91b;p=lttng-modules.git Support the hostname context This is particularly useful when tracing a machine with containers (lxc), that way we can easily distinguish events generated inside a container. [ Edit by Mathieu Desnoyers: various fix. ] Signed-off-by: Julien Desfossez Signed-off-by: Mathieu Desnoyers --- diff --git a/Makefile b/Makefile index b91113e4..d4b09bbe 100644 --- a/Makefile +++ b/Makefile @@ -20,7 +20,7 @@ lttng-tracer-objs := lttng-events.o lttng-abi.o \ lttng-context-vpid.o lttng-context-tid.o \ lttng-context-vtid.o lttng-context-ppid.o \ lttng-context-vppid.o lttng-calibrate.o \ - wrapper/random.o + lttng-context-hostname.o wrapper/random.o obj-m += lttng-statedump.o lttng-statedump-objs := lttng-statedump-impl.o wrapper/irqdesc.o diff --git a/lttng-abi.c b/lttng-abi.c index 26a02edc..eadf0a88 100644 --- a/lttng-abi.c +++ b/lttng-abi.c @@ -195,6 +195,8 @@ long lttng_abi_add_context(struct file *file, ctx); case LTTNG_KERNEL_CONTEXT_PROCNAME: return lttng_add_procname_to_ctx(ctx); + case LTTNG_KERNEL_CONTEXT_HOSTNAME: + return lttng_add_hostname_to_ctx(ctx); default: return -EINVAL; } diff --git a/lttng-abi.h b/lttng-abi.h index dc230d86..cf72b12b 100644 --- a/lttng-abi.h +++ b/lttng-abi.h @@ -123,6 +123,7 @@ enum lttng_kernel_context_type { LTTNG_KERNEL_CONTEXT_VTID = 7, LTTNG_KERNEL_CONTEXT_PPID = 8, LTTNG_KERNEL_CONTEXT_VPPID = 9, + LTTNG_KERNEL_CONTEXT_HOSTNAME = 10, }; struct lttng_kernel_perf_counter_ctx { diff --git a/lttng-context-hostname.c b/lttng-context-hostname.c new file mode 100644 index 00000000..e38340b7 --- /dev/null +++ b/lttng-context-hostname.c @@ -0,0 +1,97 @@ +/* + * lttng-context-hostname.c + * + * LTTng hostname context. + * + * Copyright (C) 2009-2012 Mathieu Desnoyers + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; only + * version 2.1 of the License. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#include +#include +#include +#include +#include "lttng-events.h" +#include "wrapper/ringbuffer/frontend_types.h" +#include "wrapper/vmalloc.h" +#include "lttng-tracer.h" + +#define LTTNG_HOSTNAME_CTX_LEN (__NEW_UTS_LEN + 1) + +static +size_t hostname_get_size(size_t offset) +{ + size_t size = 0; + + size += LTTNG_HOSTNAME_CTX_LEN; + return size; +} + +static +void hostname_record(struct lttng_ctx_field *field, + struct lib_ring_buffer_ctx *ctx, + struct lttng_channel *chan) +{ + struct nsproxy *nsproxy; + struct uts_namespace *ns; + char *hostname; + + rcu_read_lock(); + nsproxy = task_nsproxy(current); + if (nsproxy) { + ns = nsproxy->uts_ns; + hostname = ns->name.nodename; + chan->ops->event_write(ctx, hostname, + LTTNG_HOSTNAME_CTX_LEN); + } else { + chan->ops->event_memset(ctx, 0, + LTTNG_HOSTNAME_CTX_LEN); + } + rcu_read_unlock(); +} + +int lttng_add_hostname_to_ctx(struct lttng_ctx **ctx) +{ + struct lttng_ctx_field *field; + + field = lttng_append_context(ctx); + if (!field) + return -ENOMEM; + if (lttng_find_context(*ctx, "hostname")) { + lttng_remove_context_field(ctx, field); + return -EEXIST; + } + field->event_field.name = "hostname"; + field->event_field.type.atype = atype_array; + field->event_field.type.u.array.elem_type.atype = atype_integer; + field->event_field.type.u.array.elem_type.u.basic.integer.size = sizeof(char) * CHAR_BIT; + field->event_field.type.u.array.elem_type.u.basic.integer.alignment = lttng_alignof(char) * CHAR_BIT; + field->event_field.type.u.array.elem_type.u.basic.integer.signedness = is_signed_type(char); + field->event_field.type.u.array.elem_type.u.basic.integer.reverse_byte_order = 0; + field->event_field.type.u.array.elem_type.u.basic.integer.base = 10; + field->event_field.type.u.array.elem_type.u.basic.integer.encoding = lttng_encode_UTF8; + field->event_field.type.u.array.length = LTTNG_HOSTNAME_CTX_LEN; + + field->get_size = hostname_get_size; + field->record = hostname_record; + wrapper_vmalloc_sync_all(); + return 0; +} +EXPORT_SYMBOL_GPL(lttng_add_hostname_to_ctx); + +MODULE_LICENSE("GPL and additional rights"); +MODULE_AUTHOR("Mathieu Desnoyers"); +MODULE_DESCRIPTION("Linux Trace Toolkit Perf Support"); diff --git a/lttng-events.h b/lttng-events.h index f12d91f4..be3979ad 100644 --- a/lttng-events.h +++ b/lttng-events.h @@ -349,6 +349,7 @@ int lttng_add_tid_to_ctx(struct lttng_ctx **ctx); int lttng_add_vtid_to_ctx(struct lttng_ctx **ctx); int lttng_add_ppid_to_ctx(struct lttng_ctx **ctx); int lttng_add_vppid_to_ctx(struct lttng_ctx **ctx); +int lttng_add_hostname_to_ctx(struct lttng_ctx **ctx); #if defined(CONFIG_PERF_EVENTS) && (LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,33)) int lttng_add_perf_counter_to_ctx(uint32_t type, uint64_t config,