Re: CVS commit: src/external/gpl3/gcc/dist/libsanitizer/sanitizer_common

[Valery Ushakov <uwe%stderr.spb.ru@localhost>]

On Thu, May 24, 2018 at 12:48:52 +0200, Martin Husemann wrote:

> On Thu, May 24, 2018 at 10:33:11AM +0000, Martin Husemann wrote:
> > so there are even more bugs :-/
> 
> To sum up: both syscall(2) and __syscall(2) are very hard to use and do not
> really provide any value.
> 
> Neither of them can be used to invoke mmap(2) correctly and properly
> return the value.

You probably can by playing the horrible ABI tricks similar to what Go
does (as reported in the PR), by manually splitting 64-bit arguments
into 32-bit parts (with all the ifdefs for bitness and endianness).

But I don't think I ever saw a coherent story of why the syscall(2)
tricks are really necessary here in the sanitizers in the first place.

-uwe