svn commit: r341177 - head/sys/powerpc/powerpc

[Konstantin Belousov]

On Thu, Nov 29, 2018 at 03:39:11AM +0000, Justin Hibbits wrote:
> Author: jhibbits
> Date: Thu Nov 29 03:39:11 2018
> New Revision: 341177
> URL: https://svnweb.freebsd.org/changeset/base/341177
> 
> Log:
>   Fix thread creation in PowerPC64 ELFv2 processes.
>   
>   Summary:
>   Currently, the upcall used to create threads assumes ELFv1.
>   
>   Instead, we should check which sysentvec is in use on the process and act
>   accordingly.
>   
>   This makes ELFv2 threaded processes work.
>   
>   Submitted by:	git_bdragon.rtk0.net
>   Differential Revision: https://reviews.freebsd.org/D18330
> 
> Modified:
>   head/sys/powerpc/powerpc/exec_machdep.c
> 
> Modified: head/sys/powerpc/powerpc/exec_machdep.c
> ==============================================================================
> --- head/sys/powerpc/powerpc/exec_machdep.c	Thu Nov 29 02:52:08 2018	(r341176)
> +++ head/sys/powerpc/powerpc/exec_machdep.c	Thu Nov 29 03:39:11 2018	(r341177)
> @@ -124,6 +124,10 @@ static int	grab_mcontext32(struct thread *td, mcontext
>  
>  static int	grab_mcontext(struct thread *, mcontext_t *, int);
>  
> +#ifdef __powerpc64__
> +extern struct sysentvec elf64_freebsd_sysvec_v2;
> +#endif
> +
>  void
>  sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask)
>  {
> @@ -1014,11 +1018,18 @@ cpu_set_upcall(struct thread *td, void (*entry)(void *
>  		#endif
>  	} else {
>  	    #ifdef __powerpc64__
> -		register_t entry_desc[3];
> -		(void)copyin((void *)entry, entry_desc, sizeof(entry_desc));
> -		tf->srr0 = entry_desc[0];
> -		tf->fixreg[2] = entry_desc[1];
> -		tf->fixreg[11] = entry_desc[2];
> +		if (td->td_proc->p_sysent == &elf64_freebsd_sysvec_v2) {
I recommend you to not do this, instead add a new sv_flag to indicate
ELFv2 for PPC.  We already have almost machine-specific flags like ia32.

> +			tf->srr0 = (register_t)entry;
> +			/* ELFv2 ABI requires that the global entry point be in r12. */
> +			tf->fixreg[12] = (register_t)entry;
> +		}
> +		else {
> +			register_t entry_desc[3];
> +			(void)copyin((void *)entry, entry_desc, sizeof(entry_desc));
> +			tf->srr0 = entry_desc[0];
> +			tf->fixreg[2] = entry_desc[1];
> +			tf->fixreg[11] = entry_desc[2];
> +		}
>  		tf->srr1 = psl_userset | PSL_FE_DFLT;
>  	    #endif
>  	}