fix build with -fno-common

fix-build-with-fno-common.patch

@@ -0,0 +1,44 @@
+From 21a934df4c683e73e0a66a9afca33573fcf9d789 Mon Sep 17 00:00:00 2001
+From: Michael Jeanson <mjeanson@efficios.com>
+Date: Thu, 16 Jan 2020 10:59:14 -0500
+Subject: [PATCH] Fix: build with -fno-common
+
+GCC 10 will default to building with -fno-common, this inhibits the
+linker from merging multiple tentative definitions of a symbol in an
+archive. Keep only the declaration in the libustsnprintf.la convenience
+library.
+
+Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
+Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+Change-Id: I8fb7c72811ce7e62f10342f55fcabeeabfdd4c67
+---
+ liblttng-ust-ctl/ustctl.c      | 2 --
+ liblttng-ust-fd/lttng-ust-fd.c | 2 --
+ 2 files changed, 4 deletions(-)
+
+diff --git a/liblttng-ust-ctl/ustctl.c b/liblttng-ust-ctl/ustctl.c
+index 949ece17a..c2b761a1b 100644
+--- a/liblttng-ust-ctl/ustctl.c
++++ b/liblttng-ust-ctl/ustctl.c
+@@ -77,8 +77,6 @@ extern void lttng_ring_buffer_client_discard_exit(void);
+ extern void lttng_ring_buffer_client_discard_rt_exit(void);
+ extern void lttng_ring_buffer_metadata_client_exit(void);
+ 
+-volatile enum ust_loglevel ust_loglevel;
+-
+ int ustctl_release_handle(int sock, int handle)
+ {
+ 	struct ustcomm_ust_msg lum;
+diff --git a/liblttng-ust-fd/lttng-ust-fd.c b/liblttng-ust-fd/lttng-ust-fd.c
+index 863f0618a..4818e02ed 100644
+--- a/liblttng-ust-fd/lttng-ust-fd.c
++++ b/liblttng-ust-fd/lttng-ust-fd.c
+@@ -28,8 +28,6 @@
+ #include <helper.h>
+ #include "usterr-signal-safe.h"
+ 
+-volatile enum ust_loglevel ust_loglevel;
+-
+ static int (*__lttng_ust_fd_plibc_close)(int fd);
+ static int (*__lttng_ust_fd_plibc_fclose)(FILE *stream);
+ 

lttng-ust.spec

@@ -1,6 +1,6 @@
 Name:           lttng-ust
 Version:        2.10.1
-Release:        9
+Release:        10
 Summary:        LTTng Userspace Tracer library
 License:        LGPLv2 and GPLv2 and MIT
 URL:            https://lttng.org
@@ -8,6 +8,7 @@ URL:            https://lttng.org
 Source0:        https://lttng.org/files/lttng-ust/%{name}-%{version}.tar.bz2
 Patch0:         Fix-namespace-our-gettid-wrapper.patch
 Patch1:         lttng-gen-tp-shebang.patch
+patch2:		fix-build-with-fno-common.patch
 
 BuildRequires:  libuuid-devel autoconf automake libtool
 BuildRequires:  userspace-rcu-devel >= 0.8.0
@@ -60,6 +61,9 @@ make check
 %{_docdir}/%{name}/*
 
 %changelog
+* Fri Jul 30 2021 zhouwenpei <zhouwenpei1@huawei.com> - 2.10.1-10
+- fix build with -fno-common
+
 * Mon Nov 02 2020 xinghe <xinghe1@huawei.com> - 2.10.1-9
 - fix lttng-gen-tp command