From: Xie XiuQi <xiexiuqi@huawei.com>

Commit 97d5f2e9ee12 ("tools api fs: More thread safety for global
filesystem variables") introduces pthread_once, so the libpthread
should be added at link time, or we'll meet the following compile
error when 'make -C tools/mm':

  gcc -Wall -Wextra -I../lib/ -o page-types page-types.c ../lib/api/libapi.a
  ~/linux/tools/lib/api/fs/fs.c:146: undefined reference to `pthread_once'
  ~/linux/tools/lib/api/fs/fs.c:147: undefined reference to `pthread_once'
  ~/linux/tools/lib/api/fs/fs.c:148: undefined reference to `pthread_once'
  ~/linux/tools/lib/api/fs/fs.c:149: undefined reference to `pthread_once'
  ~/linux/tools/lib/api/fs/fs.c:150: undefined reference to `pthread_once'
  /usr/bin/ld: ../lib/api/libapi.a(libapi-in.o):~/linux/tools/lib/api/fs/fs.c:151:
  more undefined references to `pthread_once' follow
  collect2: error: ld returned 1 exit status
  make: *** [Makefile:22: page-types] Error 1

Fixes: 97d5f2e9ee12 ("tools api fs: More thread safety for global filesystem variables")
Signed-off-by: Xie XiuQi <xiexiuqi@huawei.com>
Acked-by: Ian Rogers <irogers@google.com>
---
 tools/mm/Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/mm/Makefile b/tools/mm/Makefile
index 6c1da51f4177..9997b2e401ae 100644
--- a/tools/mm/Makefile
+++ b/tools/mm/Makefile
@@ -9,7 +9,7 @@ LIB_DIR = ../lib/api
 LIBS = $(LIB_DIR)/libapi.a
 
 CFLAGS += -Wall -Wextra -I../lib/
-LDFLAGS += $(LIBS)
+LDFLAGS += $(LIBS) -lpthread
 
 all: $(TARGETS)
 
-- 
2.25.1

On Mon, Aug 28, 2023 at 08:21:57PM +0800, Xie XiuQi wrote:
> diff --git a/tools/mm/Makefile b/tools/mm/Makefile
> index 6c1da51f4177..9997b2e401ae 100644
> --- a/tools/mm/Makefile
> +++ b/tools/mm/Makefile
> @@ -9,7 +9,7 @@ LIB_DIR = ../lib/api
>  LIBS = $(LIB_DIR)/libapi.a
>  
>  CFLAGS += -Wall -Wextra -I../lib/
> -LDFLAGS += $(LIBS)
> +LDFLAGS += $(LIBS) -lpthread

Is this the right fix?  I'm pretty sure you're suppose to use -pthread
in CFLAGS in case there are other things the compiler/linker/whatever
need.

'-pthread'
     Define additional macros required for using the POSIX threads
     library.  You should use this option consistently for both
     compilation and linking.  This option is supported on GNU/Linux
     targets, most other Unix derivatives, and also on x86 Cygwin and
     MinGW targets.

Hi,

On 2023/8/28 20:58, Matthew Wilcox wrote:
> On Mon, Aug 28, 2023 at 08:21:57PM +0800, Xie XiuQi wrote:
>> diff --git a/tools/mm/Makefile b/tools/mm/Makefile
>> index 6c1da51f4177..9997b2e401ae 100644
>> --- a/tools/mm/Makefile
>> +++ b/tools/mm/Makefile
>> @@ -9,7 +9,7 @@ LIB_DIR = ../lib/api
>>  LIBS = $(LIB_DIR)/libapi.a
>>  
>>  CFLAGS += -Wall -Wextra -I../lib/
>> -LDFLAGS += $(LIBS)
>> +LDFLAGS += $(LIBS) -lpthread
> 
> Is this the right fix?  I'm pretty sure you're suppose to use -pthread
> in CFLAGS in case there are other things the compiler/linker/whatever
> need.
> 

Thanks for your comment. I'll fix it and send v2.

> '-pthread'
>      Define additional macros required for using the POSIX threads
>      library.  You should use this option consistently for both
>      compilation and linking.  This option is supported on GNU/Linux
>      targets, most other Unix derivatives, and also on x86 Cygwin and
>      MinGW targets.
>

On Thu, Aug 31, 2023 at 09:13:24AM +0800, Xie XiuQi wrote:
> Hi,
> 
> On 2023/8/28 20:58, Matthew Wilcox wrote:
> > On Mon, Aug 28, 2023 at 08:21:57PM +0800, Xie XiuQi wrote:
> >> diff --git a/tools/mm/Makefile b/tools/mm/Makefile
> >> index 6c1da51f4177..9997b2e401ae 100644
> >> --- a/tools/mm/Makefile
> >> +++ b/tools/mm/Makefile
> >> @@ -9,7 +9,7 @@ LIB_DIR = ../lib/api
> >>  LIBS = $(LIB_DIR)/libapi.a
> >>  
> >>  CFLAGS += -Wall -Wextra -I../lib/
> >> -LDFLAGS += $(LIBS)
> >> +LDFLAGS += $(LIBS) -lpthread
> > 
> > Is this the right fix?  I'm pretty sure you're suppose to use -pthread
> > in CFLAGS in case there are other things the compiler/linker/whatever
> > need.
> > 
> 
> Thanks for your comment. I'll fix it and send v2.

You added it to LDFLAGS, not CFLAGS.

> > '-pthread'
> >      Define additional macros required for using the POSIX threads
> >      library.  You should use this option consistently for both
                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> >      compilation and linking.  This option is supported on GNU/Linux
         ^^^^^^^^^^^^^^^^^^^^^^^
> >      targets, most other Unix derivatives, and also on x86 Cygwin and
> >      MinGW targets.
> > 
> 
>

Hi,

On 2023/8/31 10:25, Matthew Wilcox wrote:
> On Thu, Aug 31, 2023 at 09:13:24AM +0800, Xie XiuQi wrote:
>> Hi,
>>
>> On 2023/8/28 20:58, Matthew Wilcox wrote:
>>> On Mon, Aug 28, 2023 at 08:21:57PM +0800, Xie XiuQi wrote:
>>>> diff --git a/tools/mm/Makefile b/tools/mm/Makefile
>>>> index 6c1da51f4177..9997b2e401ae 100644
>>>> --- a/tools/mm/Makefile
>>>> +++ b/tools/mm/Makefile
>>>> @@ -9,7 +9,7 @@ LIB_DIR = ../lib/api
>>>>  LIBS = $(LIB_DIR)/libapi.a
>>>>  
>>>>  CFLAGS += -Wall -Wextra -I../lib/
>>>> -LDFLAGS += $(LIBS)
>>>> +LDFLAGS += $(LIBS) -lpthread
>>>
>>> Is this the right fix?  I'm pretty sure you're suppose to use -pthread
>>> in CFLAGS in case there are other things the compiler/linker/whatever
>>> need.
>>>
>>
>> Thanks for your comment. I'll fix it and send v2.
> 
> You added it to LDFLAGS, not CFLAGS.

Sorry, it's my fault. I'll add it to CFALGS:

  CFLAGS += -Wall -Wextra -I../lib/ -pthread

> 
>>> '-pthread'
>>>      Define additional macros required for using the POSIX threads
>>>      library.  You should use this option consistently for both
>                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>>>      compilation and linking.  This option is supported on GNU/Linux
>          ^^^^^^^^^^^^^^^^^^^^^^^
>>>      targets, most other Unix derivatives, and also on x86 Cygwin and
>>>      MinGW targets.
>>>
>>
>>