X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=liblttng-ust%2Flttng-context-vsuid.c;h=56f3d0738cad1280f8f0df267ee3bdc3769cb454;hb=HEAD;hp=650ee7c63c84a3597e87340ba17592c111d0c900;hpb=fb54defd7e47e106bdf3b7eb07d53f0aba0525ec;p=lttng-ust.git diff --git a/liblttng-ust/lttng-context-vsuid.c b/liblttng-ust/lttng-context-vsuid.c deleted file mode 100644 index 650ee7c6..00000000 --- a/liblttng-ust/lttng-context-vsuid.c +++ /dev/null @@ -1,132 +0,0 @@ -/* - * lttng-context-vsuid.c - * - * LTTng UST namespaced saved set-user ID 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 "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 uid_t cached_vsuid = INVALID_UID; - -static -uid_t get_vsuid(void) -{ - uid_t vsuid; - - vsuid = CMM_LOAD_SHARED(cached_vsuid); - - if (caa_unlikely(vsuid == INVALID_UID)) { - uid_t uid, euid, suid; - - if (getresuid(&uid, &euid, &suid) == 0) { - vsuid = suid; - CMM_STORE_SHARED(cached_vsuid, vsuid); - } - } - - return vsuid; -} - -/* - * The vsuid can change on setuid, setreuid and setresuid. - */ -void lttng_context_vsuid_reset(void) -{ - CMM_STORE_SHARED(cached_vsuid, INVALID_UID); -} - -static -size_t vsuid_get_size(struct lttng_ctx_field *field, size_t offset) -{ - size_t size = 0; - - size += lib_ring_buffer_align(offset, lttng_alignof(uid_t)); - size += sizeof(uid_t); - return size; -} - -static -void vsuid_record(struct lttng_ctx_field *field, - struct lttng_ust_lib_ring_buffer_ctx *ctx, - struct lttng_channel *chan) -{ - uid_t vsuid; - - vsuid = get_vsuid(); - lib_ring_buffer_align_ctx(ctx, lttng_alignof(vsuid)); - chan->ops->event_write(ctx, &vsuid, sizeof(vsuid)); -} - -static -void vsuid_get_value(struct lttng_ctx_field *field, - struct lttng_ctx_value *value) -{ - value->u.s64 = get_vsuid(); -} - -int lttng_add_vsuid_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, "vsuid")) { - lttng_remove_context_field(ctx, field); - return -EEXIST; - } - field->event_field.name = "vsuid"; - field->event_field.type.atype = atype_integer; - field->event_field.type.u.integer.size = sizeof(uid_t) * CHAR_BIT; - field->event_field.type.u.integer.alignment = lttng_alignof(uid_t) * CHAR_BIT; - field->event_field.type.u.integer.signedness = lttng_is_signed_type(uid_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 = vsuid_get_size; - field->record = vsuid_record; - field->get_value = vsuid_get_value; - lttng_context_update(*ctx); - return 0; -}