On Wed, Nov 27, 2013 at 01:54:15PM +0100, Daniel Borkmann wrote: > On 11/26/2013 10:44 PM, Cesar Eduardo Barros wrote: > >Em 26-11-2013 17:27, Daniel Borkmann escreveu: > >>On 11/26/2013 01:00 AM, Cesar Eduardo Barros wrote: > >>>Compile-tested on x86_64. > >> > >>Actually with yet another version, I hoped that the "compile-tested"-only > >>statement would eventually disappear, ohh well. ;) > > > >I did compile test each version ;-) including verifying (with "make > >crypto/memneq.i") that the macro was really generating the expected inline > >assembly (with these #ifdef chains, one has to be careful with typos). > > > >(Actually, I compile tested with "make crypto/memneq.o crypto/memneq.s > >crypto/memneq.i". I took a peek at the assembly to see if it made sense.) > > > >>Resolving the OPTIMIZER_HIDE_VAR() macro for others than GCC jnto a > >>barrier() seems a bit suboptimal, but assuming 99% of people will use > >>GCC anyway, then for the minority of the remaining, they will worst case > >>have a clever compiler and eventually mimic memcmp() in some situations, > >>or have a not-so-clever compiler and execute the full code as is. > > > >I do not think any compiler other than gcc and icc can compile unmodified > >upstream kernel code. LLVM's clang would be the one which comes closest, but > >it has gcc-compatible inline assembly, as does icc AFAIK. > > > >The #define to barrier() within compiler-intel.h is for some compiler called > >ECC (not icc). From what I could find about it on a quick search, it appears > >to be some kind of Itanium compiler. > > > >That part of the header was added back in 2003, and I do not believe it is > >still relevant. A comment within that #ifdef block says "Intel ECC compiler > >doesn't support gcc specific asm stmts", but there are many uses of > >unprotected inline assembly all over the kernel (including on the ia64 > >headers), so if that comment is true, the kernel will not compile with that > >compiler. It is probably a piece of leftover dead code. I only added to it > >because I am following RELOC_HIDE's example, and RELOC_HIDE is there. > > Yep. > > Acked-by: Daniel Borkmann <dbork...@redhat.com>
Patch applied. Thanks! -- Email: Herbert Xu <herb...@gondor.apana.org.au> Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
