X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=liblttng-ust%2Flttng-context-uts-ns.c;h=fb2d89f94bfa3ceee709fce0179e0dfb7c64a22e;hb=HEAD;hp=13b7a46985b2b1ebb5bf658eccb8df154d06392d;hpb=cc58956cca1b3864a02b80882ead818b23225295;p=lttng-ust.git diff --git a/liblttng-ust/lttng-context-uts-ns.c b/liblttng-ust/lttng-context-uts-ns.c deleted file mode 100644 index 13b7a469..00000000 --- a/liblttng-ust/lttng-context-uts-ns.c +++ /dev/null @@ -1,165 +0,0 @@ -/* - * lttng-context-uts-ns.c - * - * LTTng UST uts namespace context. - * - * Copyright (C) 2009-2012 Mathieu Desnoyers - * 2019 Michael Jeanson - * - * 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 - */ - -#define _LGPL_SOURCE -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include "lttng-tracer-core.h" -#include "ns.h" - - -/* - * We cache the result to ensure we don't stat(2) the proc filesystem on - * each event. - */ -static DEFINE_URCU_TLS_INIT(ino_t, cached_uts_ns, NS_INO_UNINITIALIZED); - -static -ino_t get_uts_ns(void) -{ - struct stat sb; - ino_t uts_ns; - - uts_ns = CMM_LOAD_SHARED(URCU_TLS(cached_uts_ns)); - - /* - * If the cache is populated, do nothing and return the - * cached inode number. - */ - if (caa_likely(uts_ns != NS_INO_UNINITIALIZED)) - return uts_ns; - - /* - * At this point we have to populate the cache, set the initial - * value to NS_INO_UNAVAILABLE (0), if we fail to get the inode - * number from the proc filesystem, this is the value we will - * cache. - */ - uts_ns = NS_INO_UNAVAILABLE; - - /* - * /proc/thread-self was introduced in kernel v3.17 - */ - if (stat("/proc/thread-self/ns/uts", &sb) == 0) { - uts_ns = sb.st_ino; - } else { - char proc_ns_path[LTTNG_PROC_NS_PATH_MAX]; - - if (snprintf(proc_ns_path, LTTNG_PROC_NS_PATH_MAX, - "/proc/self/task/%d/ns/uts", - lttng_gettid()) >= 0) { - - if (stat(proc_ns_path, &sb) == 0) { - uts_ns = sb.st_ino; - } - } - } - - /* - * And finally, store the inode number in the cache. - */ - CMM_STORE_SHARED(URCU_TLS(cached_uts_ns), uts_ns); - - return uts_ns; -} - -/* - * The uts namespace can change for 3 reasons - * * clone(2) called with CLONE_NEWUTS - * * setns(2) called with the fd of a different uts ns - * * unshare(2) called with CLONE_NEWUTS - */ -void lttng_context_uts_ns_reset(void) -{ - CMM_STORE_SHARED(URCU_TLS(cached_uts_ns), NS_INO_UNINITIALIZED); -} - -static -size_t uts_ns_get_size(struct lttng_ctx_field *field, size_t offset) -{ - size_t size = 0; - - size += lib_ring_buffer_align(offset, lttng_alignof(ino_t)); - size += sizeof(ino_t); - return size; -} - -static -void uts_ns_record(struct lttng_ctx_field *field, - struct lttng_ust_lib_ring_buffer_ctx *ctx, - struct lttng_channel *chan) -{ - ino_t uts_ns; - - uts_ns = get_uts_ns(); - lib_ring_buffer_align_ctx(ctx, lttng_alignof(uts_ns)); - chan->ops->event_write(ctx, &uts_ns, sizeof(uts_ns)); -} - -static -void uts_ns_get_value(struct lttng_ctx_field *field, - struct lttng_ctx_value *value) -{ - value->u.s64 = get_uts_ns(); -} - -int lttng_add_uts_ns_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, "uts_ns")) { - lttng_remove_context_field(ctx, field); - return -EEXIST; - } - field->event_field.name = "uts_ns"; - field->event_field.type.atype = atype_integer; - field->event_field.type.u.basic.integer.size = sizeof(ino_t) * CHAR_BIT; - field->event_field.type.u.basic.integer.alignment = lttng_alignof(ino_t) * CHAR_BIT; - field->event_field.type.u.basic.integer.signedness = lttng_is_signed_type(ino_t); - field->event_field.type.u.basic.integer.reverse_byte_order = 0; - field->event_field.type.u.basic.integer.base = 10; - field->event_field.type.u.basic.integer.encoding = lttng_encode_none; - field->get_size = uts_ns_get_size; - field->record = uts_ns_record; - field->get_value = uts_ns_get_value; - lttng_context_update(*ctx); - return 0; -} - -/* - * * Force a read (imply TLS fixup for dlopen) of TLS variables. - * */ -void lttng_fixup_uts_ns_tls(void) -{ - asm volatile ("" : : "m" (URCU_TLS(cached_uts_ns))); -}