X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=liblttng-ust%2Flttng-context-pid-ns.c;h=1581fb3dc3ed641f36906b4bd43ed657ae9a8c3b;hb=HEAD;hp=4a690b7d24e84e3b3361eb57679a4cd7000cb8c4;hpb=218deb69baab57ee2f6728eef18e84697f21197b;p=lttng-ust.git diff --git a/liblttng-ust/lttng-context-pid-ns.c b/liblttng-ust/lttng-context-pid-ns.c deleted file mode 100644 index 4a690b7d..00000000 --- a/liblttng-ust/lttng-context-pid-ns.c +++ /dev/null @@ -1,143 +0,0 @@ -/* - * lttng-context-pid-ns.c - * - * LTTng UST pid 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 "ns.h" - -/* - * We cache the result to ensure we don't stat(2) the proc filesystem on - * each event. The PID namespace is global to the process. - */ -static ino_t cached_pid_ns = NS_INO_UNINITIALIZED; - -static -ino_t get_pid_ns(void) -{ - struct stat sb; - ino_t pid_ns; - - pid_ns = CMM_LOAD_SHARED(cached_pid_ns); - - /* - * If the cache is populated, do nothing and return the - * cached inode number. - */ - if (caa_likely(pid_ns != NS_INO_UNINITIALIZED)) - return pid_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. - */ - pid_ns = NS_INO_UNAVAILABLE; - - if (stat("/proc/self/ns/pid", &sb) == 0) { - pid_ns = sb.st_ino; - } - - /* - * And finally, store the inode number in the cache. - */ - CMM_STORE_SHARED(cached_pid_ns, pid_ns); - - return pid_ns; -} - -/* - * A process's PID namespace membership is determined when the process is - * created and cannot be changed thereafter. - * - * The pid namespace can change only on clone(2) / fork(2) : - * - clone(2) with the CLONE_NEWPID flag - * - clone(2) / fork(2) after a call to unshare(2) with the CLONE_NEWPID flag - * - clone(2) / fork(2) after a call to setns(2) with a PID namespace fd - */ -void lttng_context_pid_ns_reset(void) -{ - CMM_STORE_SHARED(cached_pid_ns, NS_INO_UNINITIALIZED); -} - -static -size_t pid_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 pid_ns_record(struct lttng_ctx_field *field, - struct lttng_ust_lib_ring_buffer_ctx *ctx, - struct lttng_channel *chan) -{ - ino_t pid_ns; - - pid_ns = get_pid_ns(); - lib_ring_buffer_align_ctx(ctx, lttng_alignof(pid_ns)); - chan->ops->event_write(ctx, &pid_ns, sizeof(pid_ns)); -} - -static -void pid_ns_get_value(struct lttng_ctx_field *field, - struct lttng_ctx_value *value) -{ - value->u.s64 = get_pid_ns(); -} - -int lttng_add_pid_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, "pid_ns")) { - lttng_remove_context_field(ctx, field); - return -EEXIST; - } - field->event_field.name = "pid_ns"; - field->event_field.type.atype = atype_integer; - field->event_field.type.u.integer.size = sizeof(ino_t) * CHAR_BIT; - field->event_field.type.u.integer.alignment = lttng_alignof(ino_t) * CHAR_BIT; - field->event_field.type.u.integer.signedness = lttng_is_signed_type(ino_t); - field->event_field.type.u.integer.reverse_byte_order = 0; - field->event_field.type.u.integer.base = 10; - field->event_field.type.u.integer.encoding = lttng_encode_none; - field->get_size = pid_ns_get_size; - field->record = pid_ns_record; - field->get_value = pid_ns_get_value; - lttng_context_update(*ctx); - return 0; -}