From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-ID: <54AD4677.6040009@sunrus.com.cn> Date: Wed, 07 Jan 2015 22:45:11 +0800 From: Chen Gang S MIME-Version: 1.0 Subject: Re: [PATCH] s390: include: timex: Use macro CLOCK_STORE_SIZE instead of hard code number References: <54A55954.6000002@sunrus.com.cn> <20150102094625.GA4059@osiris> <54A76584.6020700@sunrus.com.cn> <20150105095948.0612e7bc@mschwide> In-Reply-To: <20150105095948.0612e7bc@mschwide> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-Archive: List-Post: To: Martin Schwidefsky Cc: Heiko Carstens , linux390@de.ibm.com, holzheu@linux.vnet.ibm.com, linux-s390@vger.kernel.org, "linux-kernel@vger.kernel.org" List-ID: On 01/05/2015 04:59 PM, Martin Schwidefsky wrote: > On Sat, 03 Jan 2015 11:44:04 +0800 > Chen Gang wrote: > >> >> Thank you for your work. >> >> In honest, originally, I was not sure whether it would cause bug (do not >> know gcc would generic incorrect code for it). :-) > > Even if the code happened to be correct it does not matter. The intention > of the sizeof() has been to get to the correct 16, not 8. The fix is > fine as it is. > Excuse me, my English is not quite well, I am not quite sure about what you said (might misunderstand what you said), so I provide the related information below for confirmation, please check, thanks. sizeof(clk) is for a pointer, not for an array (for C language, it treats array parameter as a pointer), the related demo is below: [root@localhost test]# cat ./test.c #include static inline void get_tod_clock_ext(char clk[16]) { typedef struct { char _[sizeof(clk)]; } addrtype; printf("\nsize: %ld\n", sizeof(addrtype)); } int main() { char clk[16]; get_tod_clock_ext(clk); return 0; } [root@localhost test]# cc -Wall -O2 -o test test.c [root@localhost test]# ./test size: 8 [root@localhost test]# cc -v Using built-in specs. COLLECT_GCC=cc COLLECT_LTO_WRAPPER=/usr/libexec/gcc/x86_64-redhat-linux/4.8.3/lto-wrapper Target: x86_64-redhat-linux Configured with: ../configure --prefix=/usr --mandir=/usr/share/man --infodir=/usr/share/info --with-bugurl=http://bugzilla.redhat.com/bugzilla --enable-bootstrap --enable-shared --enable-threads=posix --enable-checking=release --with-system-zlib --enable-__cxa_atexit --disable-libunwind-exceptions --enable-gnu-unique-object --enable-linker-build-id --with-linker-hash-style=gnu --enable-languages=c,c++,objc,obj-c++,java,fortran,ada,go,lto --enable-plugin --enable-initfini-array --enable-java-awt=gtk --disable-dssi --with-java-home=/usr/lib/jvm/java-1.5.0-gcj-1.5.0.0/jre --enable-libgcj-multifile --enable-java-maintainer-mode --with-ecj-jar=/usr/share/java/eclipse-ecj.jar --disable-libjava-multilib --with-isl=/builddir/build/BUILD/gcc-4.8.3-20140624/obj-x86_64-redhat-linux/isl-install --with-cloog=/builddir/build/BUILD/gcc-4.8.3-20140624/obj-x86_64-redhat-linux/cloog-install --with-tune=generic --with-arch_32=i686 --build=x86_64-redhat-linux Thread model: posix gcc version 4.8.3 20140624 (Red Hat 4.8.3-1) (GCC) [root@localhost test]# Thanks. -- Open, share, and attitude like air, water, and life which God blessed.