mdadm:compiled warning in mdadm.c:1974:29 treats as errors

mdadm:compiled warning in mdadm.c:1974:29 treats as errors

[Zhilong]

Hi,jes;
  I have found that there is mdfd returns uninitialized warning in mdadm.c. I cannot paste the logs due to I'm on holiday. Please try to issue make everything, you should see it.

Thanks,
-Zhilong 

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Re: mdadm:compiled warning in mdadm.c:1974:29 treats as errors

[jes.sorensen]

Zhilong <zlliu@suse.com> writes:
> Hi,jes;
>   I have found that there is mdfd returns uninitialized warning in
> mdadm.c. I cannot paste the logs due to I'm on holiday. Please try to
> issue make everything, you should see it.

I don't see anything here, if you have specifics, please post them.

Jes

Re: mdadm:compiled warning in mdadm.c:1974:29 treats as errors

[Liu Zhilong]

hi,

I found this compiling warning, and can reproduce on my Leap42.1, 
Leap42.2 and SLES12 SP2 with v4.8.5 version of gcc.

# gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib64/gcc/x86_64-suse-linux/4.8/lto-wrapper
Target: x86_64-suse-linux
Configured with: ../configure --prefix=/usr --infodir=/usr/share/info 
--mandir=/usr/share/man --libdir=/usr/lib64 --libexecdir=/usr/lib64 
--enable-languages=c,c++,objc,fortran,obj-c++,java,ada 
--enable-checking=release --with-gxx-include-dir=/usr/include/c++/4.8 
--enable-ssp --disable-libssp --disable-plugin 
--with-bugurl=http://bugs.opensuse.org/ --with-pkgversion='SUSE Linux' 
--disable-libgcj --disable-libmudflap --with-slibdir=/lib64 
--with-system-zlib --enable-__cxa_atexit 
--enable-libstdcxx-allocator=new --disable-libstdcxx-pch 
--enable-version-specific-runtime-libs --enable-linker-build-id 
--enable-linux-futex --program-suffix=-4.8 --without-system-libunwind 
--with-arch-32=i586 --with-tune=generic --build=x86_64-suse-linux 
--host=x86_64-suse-linux
Thread model: posix
gcc version 4.8.5 (SUSE Linux)

# make everything
... ...
mdadm.c: In function ‘main’:
mdadm.c:1974:29: error: ‘mdfd’ may be used uninitialized in this 
function [-Werror=maybe-uninitialized]
    if (dv->devname[0] == '/' || mdfd < 0)
                              ^
mdadm.c:1914:7: note: ‘mdfd’ was declared here
    int mdfd;
        ^
cc1: all warnings being treated as errors
Makefile:206: recipe for target 'mdadm.Os' failed
make: *** [mdadm.Os] Error 1

Thanks,
-Zhilong

On 04/05/2017 11:37 PM, jes.sorensen@gmail.com wrote:
> Zhilong <zlliu@suse.com> writes:
>> Hi,jes;
>>    I have found that there is mdfd returns uninitialized warning in
>> mdadm.c. I cannot paste the logs due to I'm on holiday. Please try to
>> issue make everything, you should see it.
> I don't see anything here, if you have specifics, please post them.
>
> Jes

Re: mdadm:compiled warning in mdadm.c:1974:29 treats as errors

[Jes Sorensen]

On 04/06/2017 04:21 AM, Liu Zhilong wrote:
> hi,
>
> I found this compiling warning, and can reproduce on my Leap42.1,
> Leap42.2 and SLES12 SP2 with v4.8.5 version of gcc.
>
> # gcc -v
> Using built-in specs.
> COLLECT_GCC=gcc
> COLLECT_LTO_WRAPPER=/usr/lib64/gcc/x86_64-suse-linux/4.8/lto-wrapper
> Target: x86_64-suse-linux
> Configured with: ../configure --prefix=/usr --infodir=/usr/share/info
> --mandir=/usr/share/man --libdir=/usr/lib64 --libexecdir=/usr/lib64
> --enable-languages=c,c++,objc,fortran,obj-c++,java,ada
> --enable-checking=release --with-gxx-include-dir=/usr/include/c++/4.8
> --enable-ssp --disable-libssp --disable-plugin
> --with-bugurl=http://bugs.opensuse.org/ --with-pkgversion='SUSE Linux'
> --disable-libgcj --disable-libmudflap --with-slibdir=/lib64
> --with-system-zlib --enable-__cxa_atexit
> --enable-libstdcxx-allocator=new --disable-libstdcxx-pch
> --enable-version-specific-runtime-libs --enable-linker-build-id
> --enable-linux-futex --program-suffix=-4.8 --without-system-libunwind
> --with-arch-32=i586 --with-tune=generic --build=x86_64-suse-linux
> --host=x86_64-suse-linux
> Thread model: posix
> gcc version 4.8.5 (SUSE Linux)
>
> # make everything
> ... ...
> mdadm.c: In function ‘main’:
> mdadm.c:1974:29: error: ‘mdfd’ may be used uninitialized in this
> function [-Werror=maybe-uninitialized]
>    if (dv->devname[0] == '/' || mdfd < 0)
>                              ^
> mdadm.c:1914:7: note: ‘mdfd’ was declared here
>    int mdfd;
>        ^
> cc1: all warnings being treated as errors
> Makefile:206: recipe for target 'mdadm.Os' failed
> make: *** [mdadm.Os] Error 1

Crappy compiler, you're running an old gcc. But sure, send me a patch 
that initializes mdfd to -1.

Jes

Re: mdadm:compiled warning in mdadm.c:1974:29 treats as errors

[NeilBrown]

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On Thu, Apr 06 2017, Jes Sorensen wrote:

> On 04/06/2017 04:21 AM, Liu Zhilong wrote:
>> hi,
>>
>> I found this compiling warning, and can reproduce on my Leap42.1,
>> Leap42.2 and SLES12 SP2 with v4.8.5 version of gcc.
>>
>> # gcc -v
>> Using built-in specs.
>> COLLECT_GCC=gcc
>> COLLECT_LTO_WRAPPER=/usr/lib64/gcc/x86_64-suse-linux/4.8/lto-wrapper
>> Target: x86_64-suse-linux
>> Configured with: ../configure --prefix=/usr --infodir=/usr/share/info
>> --mandir=/usr/share/man --libdir=/usr/lib64 --libexecdir=/usr/lib64
>> --enable-languages=c,c++,objc,fortran,obj-c++,java,ada
>> --enable-checking=release --with-gxx-include-dir=/usr/include/c++/4.8
>> --enable-ssp --disable-libssp --disable-plugin
>> --with-bugurl=http://bugs.opensuse.org/ --with-pkgversion='SUSE Linux'
>> --disable-libgcj --disable-libmudflap --with-slibdir=/lib64
>> --with-system-zlib --enable-__cxa_atexit
>> --enable-libstdcxx-allocator=new --disable-libstdcxx-pch
>> --enable-version-specific-runtime-libs --enable-linker-build-id
>> --enable-linux-futex --program-suffix=-4.8 --without-system-libunwind
>> --with-arch-32=i586 --with-tune=generic --build=x86_64-suse-linux
>> --host=x86_64-suse-linux
>> Thread model: posix
>> gcc version 4.8.5 (SUSE Linux)
>>
>> # make everything
>> ... ...
>> mdadm.c: In function ‘main’:
>> mdadm.c:1974:29: error: ‘mdfd’ may be used uninitialized in this
>> function [-Werror=maybe-uninitialized]
>>    if (dv->devname[0] == '/' || mdfd < 0)
>>                              ^
>> mdadm.c:1914:7: note: ‘mdfd’ was declared here
>>    int mdfd;
>>        ^
>> cc1: all warnings being treated as errors
>> Makefile:206: recipe for target 'mdadm.Os' failed
>> make: *** [mdadm.Os] Error 1
>
> Crappy compiler, you're running an old gcc. But sure, send me a patch 
> that initializes mdfd to -1.

I would rather make the code more obviously correct.

		if (dv->devname[0] == '/' ||
		    (mdfd = open_dev(dv->devname)) < 0)
			mdfd = open_mddev(dv->devname, 1);

well... it is more obvious to me.

NeilBrown

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Re: mdadm:compiled warning in mdadm.c:1974:29 treats as errors

[Liuzhilong]

On 04/07/2017 07:36 AM, NeilBrown wrote:
> On Thu, Apr 06 2017, Jes Sorensen wrote:
>
>> On 04/06/2017 04:21 AM, Liu Zhilong wrote:
>>> hi,
>>>
>>> I found this compiling warning, and can reproduce on my Leap42.1,
>>> Leap42.2 and SLES12 SP2 with v4.8.5 version of gcc.
>>>
>>> # gcc -v
>>> Using built-in specs.
>>> COLLECT_GCC=gcc
>>> COLLECT_LTO_WRAPPER=/usr/lib64/gcc/x86_64-suse-linux/4.8/lto-wrapper
>>> Target: x86_64-suse-linux
>>> Configured with: ../configure --prefix=/usr --infodir=/usr/share/info
>>> --mandir=/usr/share/man --libdir=/usr/lib64 --libexecdir=/usr/lib64
>>> --enable-languages=c,c++,objc,fortran,obj-c++,java,ada
>>> --enable-checking=release --with-gxx-include-dir=/usr/include/c++/4.8
>>> --enable-ssp --disable-libssp --disable-plugin
>>> --with-bugurl=http://bugs.opensuse.org/ --with-pkgversion='SUSE Linux'
>>> --disable-libgcj --disable-libmudflap --with-slibdir=/lib64
>>> --with-system-zlib --enable-__cxa_atexit
>>> --enable-libstdcxx-allocator=new --disable-libstdcxx-pch
>>> --enable-version-specific-runtime-libs --enable-linker-build-id
>>> --enable-linux-futex --program-suffix=-4.8 --without-system-libunwind
>>> --with-arch-32=i586 --with-tune=generic --build=x86_64-suse-linux
>>> --host=x86_64-suse-linux
>>> Thread model: posix
>>> gcc version 4.8.5 (SUSE Linux)
>>>
>>> # make everything
>>> ... ...
>>> mdadm.c: In function ‘main’:
>>> mdadm.c:1974:29: error: ‘mdfd’ may be used uninitialized in this
>>> function [-Werror=maybe-uninitialized]
>>>     if (dv->devname[0] == '/' || mdfd < 0)
>>>                               ^
>>> mdadm.c:1914:7: note: ‘mdfd’ was declared here
>>>     int mdfd;
>>>         ^
>>> cc1: all warnings being treated as errors
>>> Makefile:206: recipe for target 'mdadm.Os' failed
>>> make: *** [mdadm.Os] Error 1
>> Crappy compiler, you're running an old gcc. But sure, send me a patch
>> that initializes mdfd to -1.
> I would rather make the code more obviously correct.
>
> 		if (dv->devname[0] == '/' ||
> 		    (mdfd = open_dev(dv->devname)) < 0)
> 			mdfd = open_mddev(dv->devname, 1);
>
> well... it is more obvious to me.

I also consider that it's better method for this compiling warning.
And I can send this sample as a patch once jes agrees.

Thanks,
-Zhilong

> NeilBrown

Re: mdadm:compiled warning in mdadm.c:1974:29 treats as errors

[Jes Sorensen]

On 04/06/2017 07:36 PM, NeilBrown wrote:
> On Thu, Apr 06 2017, Jes Sorensen wrote:
>
>> On 04/06/2017 04:21 AM, Liu Zhilong wrote:
>>> hi,
>>>
>>> I found this compiling warning, and can reproduce on my Leap42.1,
>>> Leap42.2 and SLES12 SP2 with v4.8.5 version of gcc.
>>>
>>> # gcc -v
>>> Using built-in specs.
>>> COLLECT_GCC=gcc
>>> COLLECT_LTO_WRAPPER=/usr/lib64/gcc/x86_64-suse-linux/4.8/lto-wrapper
>>> Target: x86_64-suse-linux
>>> Configured with: ../configure --prefix=/usr --infodir=/usr/share/info
>>> --mandir=/usr/share/man --libdir=/usr/lib64 --libexecdir=/usr/lib64
>>> --enable-languages=c,c++,objc,fortran,obj-c++,java,ada
>>> --enable-checking=release --with-gxx-include-dir=/usr/include/c++/4.8
>>> --enable-ssp --disable-libssp --disable-plugin
>>> --with-bugurl=http://bugs.opensuse.org/ --with-pkgversion='SUSE Linux'
>>> --disable-libgcj --disable-libmudflap --with-slibdir=/lib64
>>> --with-system-zlib --enable-__cxa_atexit
>>> --enable-libstdcxx-allocator=new --disable-libstdcxx-pch
>>> --enable-version-specific-runtime-libs --enable-linker-build-id
>>> --enable-linux-futex --program-suffix=-4.8 --without-system-libunwind
>>> --with-arch-32=i586 --with-tune=generic --build=x86_64-suse-linux
>>> --host=x86_64-suse-linux
>>> Thread model: posix
>>> gcc version 4.8.5 (SUSE Linux)
>>>
>>> # make everything
>>> ... ...
>>> mdadm.c: In function ‘main’:
>>> mdadm.c:1974:29: error: ‘mdfd’ may be used uninitialized in this
>>> function [-Werror=maybe-uninitialized]
>>>    if (dv->devname[0] == '/' || mdfd < 0)
>>>                              ^
>>> mdadm.c:1914:7: note: ‘mdfd’ was declared here
>>>    int mdfd;
>>>        ^
>>> cc1: all warnings being treated as errors
>>> Makefile:206: recipe for target 'mdadm.Os' failed
>>> make: *** [mdadm.Os] Error 1
>>
>> Crappy compiler, you're running an old gcc. But sure, send me a patch
>> that initializes mdfd to -1.
>
> I would rather make the code more obviously correct.
>
> 		if (dv->devname[0] == '/' ||
> 		    (mdfd = open_dev(dv->devname)) < 0)
> 			mdfd = open_mddev(dv->devname, 1);
>
> well... it is more obvious to me.

I really don't like these convoluted if statements, especially the 
recursive assignment of mdfd here.

Cheers,
Jes

[PATCH] mdadm.c:fix compile warning "mdfd is uninitialized"

[Zhilong Liu]

Initialized the mdfd as -1 to prevent compile error
of some compilers.
For example, gcc version 4.8.5(SUSE Linux).

Signed-off-by: Zhilong Liu <zlliu@suse.com>
---
 mdadm.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mdadm.c b/mdadm.c
index 001ff68..41dae1d 100644
--- a/mdadm.c
+++ b/mdadm.c
@@ -1916,7 +1916,7 @@ static int misc_list(struct mddev_dev *devlist,
 	int rv = 0;
 
 	for (dv = devlist; dv; dv = (rv & 16) ? NULL : dv->next) {
-		int mdfd;
+		int mdfd = -1;
 
 		switch(dv->disposition) {
 		case 'D':
-- 
2.6.6

Re: [PATCH] mdadm.c:fix compile warning "mdfd is uninitialized"

[Jes Sorensen]

On 04/10/2017 12:49 AM, Zhilong Liu wrote:
> Initialized the mdfd as -1 to prevent compile error
> of some compilers.
> For example, gcc version 4.8.5(SUSE Linux).
>
> Signed-off-by: Zhilong Liu <zlliu@suse.com>
> ---
>  mdadm.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

Applied!

Thanks,
Jes