[OpenAFS-devel] LWP and clang

[chas williams - CONTRACTOR]

On Wed, 16 Oct 2013 15:39:05 -0400 (EDT)
Benjamin Kaduk <kaduk@MIT.EDU> wrote:

> Yeah, if I tweak rsp before stepping into the listener proc from 
> Create_Process_Part2, there's no SIGBUS.
> 
> Switching FBSD to use the same block as sys_x86_darwin_80 at line 396 of 
> lwp.c lets aklog run to completion.  I'm not sure what it will take to 
> convince me that this is right for the right reasons, though.

#ifdef sys_x86_darwin_80
        savecontext(Create_Process_Part2, &temp2->context, stackptr + stacksize - 16 - sizeof(void *)); /* 16 = 2 * jmp_buf_type */
#else /* !sys_x86_darwin_80 */
        /* Need to have the sp on an 8-byte boundary for storing doubles. */
        savecontext(Create_Process_Part2, &temp2->context, stackptr + stacksize - 16);  /* 16 = 2 * jmp_buf_type */
#endif /* !sys_x86_darwin_80 */

This doesn't do anything special to align the stack data area.  If it
is affecting alignment, it would be coincidental.