X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=liblttng-ust%2Flttng-context-uts-ns.c;h=fb2d89f94bfa3ceee709fce0179e0dfb7c64a22e;hb=HEAD;hp=5ba06f6e182f5a9c043e7f3cb60ee49412e21a79;hpb=4e48b5d2debaf6c0c598489c183cc6cb2125c8a3;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 5ba06f6e..00000000 --- a/liblttng-ust/lttng-context-uts-ns.c +++ /dev/null @@ -1,157 +0,0 @@ -/* - * SPDX-License-Identifier: LGPL-2.1-only - * - * Copyright (C) 2009-2012 Mathieu Desnoyers - * Copyright (C) 2019 Michael Jeanson - * - * LTTng UST uts namespace context. - */ - -#define _LGPL_SOURCE -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include - -#include "context-internal.h" -#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(void *priv __attribute__((unused)), - size_t offset) -{ - size_t size = 0; - - size += lttng_ust_lib_ring_buffer_align(offset, lttng_ust_rb_alignof(ino_t)); - size += sizeof(ino_t); - return size; -} - -static -void uts_ns_record(void *priv __attribute__((unused)), - struct lttng_ust_lib_ring_buffer_ctx *ctx, - struct lttng_ust_channel_buffer *chan) -{ - ino_t uts_ns; - - uts_ns = get_uts_ns(); - chan->ops->event_write(ctx, &uts_ns, sizeof(uts_ns), lttng_ust_rb_alignof(uts_ns)); -} - -static -void uts_ns_get_value(void *priv __attribute__((unused)), - struct lttng_ust_ctx_value *value) -{ - value->u.s64 = get_uts_ns(); -} - -static const struct lttng_ust_ctx_field *ctx_field = lttng_ust_static_ctx_field( - lttng_ust_static_event_field("uts_ns", - lttng_ust_static_type_integer(sizeof(ino_t) * CHAR_BIT, - lttng_ust_rb_alignof(ino_t) * CHAR_BIT, - lttng_ust_is_signed_type(ino_t), - BYTE_ORDER, 10), - false, false), - uts_ns_get_size, - uts_ns_record, - uts_ns_get_value, - NULL, NULL); - -int lttng_add_uts_ns_to_ctx(struct lttng_ust_ctx **ctx) -{ - int ret; - - if (lttng_find_context(*ctx, ctx_field->event_field->name)) { - ret = -EEXIST; - goto error_find_context; - } - ret = lttng_ust_context_append(ctx, ctx_field); - if (ret) - return ret; - return 0; - -error_find_context: - return ret; -} - -/* - * * 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))); -}