X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=liblttng-ust%2Flttng-context-vgid.c;h=7ffaf6838bcb1aef74c6c53e6fd373ec048f2469;hb=HEAD;hp=cd04e95174a6eb5b89a5905c82a915e119368bb8;hpb=3b8bedd809f1a5b56da5fc101a90b44263b0f473;p=lttng-ust.git diff --git a/liblttng-ust/lttng-context-vgid.c b/liblttng-ust/lttng-context-vgid.c deleted file mode 100644 index cd04e951..00000000 --- a/liblttng-ust/lttng-context-vgid.c +++ /dev/null @@ -1,132 +0,0 @@ -/* - * SPDX-License-Identifier: LGPL-2.1-only - * - * Copyright (C) 2009-2012 Mathieu Desnoyers - * Copyright (C) 2019 Michael Jeanson - * - * LTTng UST namespaced real group ID context. - */ - -#define _LGPL_SOURCE -#include -#include -#include -#include -#include -#include -#include -#include - -#include "context-internal.h" -#include "creds.h" - - -/* - * At the kernel level, user IDs and group IDs are a per-thread attribute. - * However, POSIX requires that all threads in a process share the same - * credentials. The NPTL threading implementation handles the POSIX - * requirements by providing wrapper functions for the various system calls - * that change process UIDs and GIDs. These wrapper functions (including those - * for setreuid() and setregid()) employ a signal-based technique to ensure - * that when one thread changes credentials, all of the other threads in the - * process also change their credentials. - */ - -/* - * We cache the result to ensure we don't trigger a system call for - * each event. User / group IDs are global to the process. - */ -static gid_t cached_vgid = INVALID_GID; - -static -gid_t get_vgid(void) -{ - gid_t vgid; - - vgid = CMM_LOAD_SHARED(cached_vgid); - - if (caa_unlikely(cached_vgid == (gid_t) -1)) { - vgid = getgid(); - CMM_STORE_SHARED(cached_vgid, vgid); - } - - return vgid; -} - -/* - * The vgid can change on setuid, setreuid and setresuid. - */ -void lttng_context_vgid_reset(void) -{ - CMM_STORE_SHARED(cached_vgid, INVALID_GID); -} - -static -size_t vgid_get_size(struct lttng_ust_ctx_field *field, size_t offset) -{ - size_t size = 0; - - size += lttng_ust_lib_ring_buffer_align(offset, lttng_alignof(gid_t)); - size += sizeof(gid_t); - return size; -} - -static -void vgid_record(struct lttng_ust_ctx_field *field, - struct lttng_ust_lib_ring_buffer_ctx *ctx, - struct lttng_ust_channel_buffer *chan) -{ - gid_t vgid; - - vgid = get_vgid(); - lttng_ust_lib_ring_buffer_align_ctx(ctx, lttng_alignof(vgid)); - chan->ops->event_write(ctx, &vgid, sizeof(vgid)); -} - -static -void vgid_get_value(struct lttng_ust_ctx_field *field, - struct lttng_ust_ctx_value *value) -{ - value->u.s64 = get_vgid(); -} - -int lttng_add_vgid_to_ctx(struct lttng_ust_ctx **ctx) -{ - struct lttng_ust_ctx_field *field; - struct lttng_ust_type_common *type; - int ret; - - type = lttng_ust_create_type_integer(sizeof(gid_t) * CHAR_BIT, - lttng_alignof(gid_t) * CHAR_BIT, - lttng_ust_is_signed_type(gid_t), - BYTE_ORDER, 10); - if (!type) - return -ENOMEM; - field = lttng_append_context(ctx); - if (!field) { - ret = -ENOMEM; - goto error_context; - } - if (lttng_find_context(*ctx, "vgid")) { - ret = -EEXIST; - goto error_find_context; - } - field->event_field->name = strdup("vgid"); - if (!field->event_field->name) { - ret = -ENOMEM; - goto error_name; - } - field->event_field->type = type; - field->get_size = vgid_get_size; - field->record = vgid_record; - field->get_value = vgid_get_value; - lttng_context_update(*ctx); - return 0; - -error_name: -error_find_context: - lttng_remove_context_field(ctx, field); -error_context: - lttng_ust_destroy_type(type); - return ret; -}