Re: 回复: [edk2-devel] [PATCH v1 3/3] CryptoPkg/BaseCryptLib: Fix possible uninitialized use

["Sergei Dmitrouk" <sergei@posteo.net>]

Yes, adding `-ffat-lto-objects` makes the warning appear even with GCC 5.5.0.

Regards,
Sergei

On Tue, May 18, 2021 at 08:59:05AM +0800, gaoliming wrote:
> Sergei:
>   Yes. GCC49 is LTO disable GCC tool chain. GCC5 is LTO enable tool chain.
> They both work on the different GCC version, such as gcc5, gcc6..
> 
>   https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90844 mentions
> -ffat-lto-objects option that can trig the warning with LTO option. Do you
> try it?
> 
>   If this option works, we can update GCC5 tool chain definition in
> tools_def.txt, then this issue can be detected in CI GCC5 build. 
> 
> Thanks
> Liming
> > -----邮件原件-----
> > 发件人: devel@edk2.groups.io <devel@edk2.groups.io> 代表 Sergei
> > Dmitrouk
> > 发送时间: 2021年5月15日 21:01
> > 收件人: devel@edk2.groups.io; jiewen.yao@intel.com
> > 抄送: Wang, Jian J <jian.j.wang@intel.com>; Lu, XiaoyuX
> > <xiaoyux.lu@intel.com>; Jiang, Guomin <guomin.jiang@intel.com>
> > 主题: Re: [edk2-devel] [PATCH v1 3/3] CryptoPkg/BaseCryptLib: Fix possible
> > uninitialized use
> > 
> > Hello Jiewen,
> > 
> > I get the error only for GCC49 and not for GCC5 toolchain.  CI uses GCC5.
> > 
> > So I compared build commands and this seems to depend on LTO.  Adding
> > `-flto`
> > impedes compiler's ability to detect such simple issues.
> > 
> > I've found relevant bug report, there is even fix suggestion from last
> month:
> > 
> >     https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90844
> > 
> > Regards,
> > Sergei
> > 
> > On Sat, May 15, 2021 at 12:30:44AM +0000, Yao, Jiewen wrote:
> > > Hi Sergei
> > > Thank you very much for the fix.
> > > Reviewed-by: Jiewen Yao <Jiewen.yao@intel.com>
> > >
> > > I am a little surprised why it is not caught before. It is an obvious
> logic issue.
> > >
> > > Do you think we can do anything on CI, to catch it during pre-check-in
> in the
> > future?
> > > I just feel it is burden to make it post-check-in fix.
> > >
> > >
> > > Thank you
> > > Yao Jiewen
> > >
> > > > -----Original Message-----
> > > > From: Sergei Dmitrouk <sergei@posteo.net>
> > > > Sent: Friday, May 14, 2021 8:17 PM
> > > > To: devel@edk2.groups.io
> > > > Cc: Yao, Jiewen <jiewen.yao@intel.com>; Wang, Jian J
> > <jian.j.wang@intel.com>;
> > > > Lu, XiaoyuX <xiaoyux.lu@intel.com>; Jiang, Guomin
> > <guomin.jiang@intel.com>
> > > > Subject: [PATCH v1 3/3] CryptoPkg/BaseCryptLib: Fix possible
> uninitialized
> > use
> > > >
> > > > `Result` can be used uninitialized in both functions after following
> > > > either first or second `goto` statement.
> > > >
> > > > Cc: Jiewen Yao <jiewen.yao@intel.com>
> > > > Cc: Jian J Wang <jian.j.wang@intel.com>
> > > > Cc: Xiaoyu Lu <xiaoyux.lu@intel.com>
> > > > Cc: Guomin Jiang <guomin.jiang@intel.com>
> > > > Signed-off-by: Sergei Dmitrouk <sergei@posteo.net>
> > > > ---
> > > >  CryptoPkg/Library/BaseCryptLib/Pk/CryptRsaPss.c     | 1 +
> > > >  CryptoPkg/Library/BaseCryptLib/Pk/CryptRsaPssSign.c | 1 +
> > > >  2 files changed, 2 insertions(+)
> > > >
> > > > diff --git a/CryptoPkg/Library/BaseCryptLib/Pk/CryptRsaPss.c
> > > > b/CryptoPkg/Library/BaseCryptLib/Pk/CryptRsaPss.c
> > > > index 4009d37d5f91..0b2960f06c4c 100644
> > > > --- a/CryptoPkg/Library/BaseCryptLib/Pk/CryptRsaPss.c
> > > > +++ b/CryptoPkg/Library/BaseCryptLib/Pk/CryptRsaPss.c
> > > > @@ -82,6 +82,7 @@ RsaPssVerify (
> > > >    EVP_PKEY_CTX *KeyCtx;
> > > >    CONST EVP_MD  *HashAlg;
> > > >
> > > > +  Result = FALSE;
> > > >    EvpRsaKey = NULL;
> > > >    EvpVerifyCtx = NULL;
> > > >    KeyCtx = NULL;
> > > > diff --git a/CryptoPkg/Library/BaseCryptLib/Pk/CryptRsaPssSign.c
> > > > b/CryptoPkg/Library/BaseCryptLib/Pk/CryptRsaPssSign.c
> > > > index b66b6f7296ad..ece765f9ae0a 100644
> > > > --- a/CryptoPkg/Library/BaseCryptLib/Pk/CryptRsaPssSign.c
> > > > +++ b/CryptoPkg/Library/BaseCryptLib/Pk/CryptRsaPssSign.c
> > > > @@ -97,6 +97,7 @@ RsaPssSign (
> > > >    EVP_PKEY_CTX          *KeyCtx;
> > > >    CONST EVP_MD          *HashAlg;
> > > >
> > > > +  Result = FALSE;
> > > >    EvpRsaKey = NULL;
> > > >    EvpVerifyCtx = NULL;
> > > >    KeyCtx = NULL;
> > > > --
> > > > 2.17.6
> > 
> > 
> > 
> > 
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