[Devel] Re: [PATCH 2/2] clone_with_pids: define the s390 syscall

[Oren Laadan]

Applied.

Serge E. Hallyn wrote:
> Gah, sorry, git user error.  syscalls.S update was not in the patch.
> Here is an update:
> 
> thanks,
> -serge
> 
> From 788c5bcc14211608f187f36d327a9d6d87b19755 Mon Sep 17 00:00:00 2001
> From: Serge E. Hallyn <serue at us.ibm.com>
> Date: Mon, 15 Jun 2009 12:14:11 -0400
> Subject: [PATCH 2/2] clone_with_pids: define the s390 syscall
> 
> Hook up the clone_with_pids system call for s390x.  clone_with_pids()
> takes an additional argument over clone(), which we pass in through
> register 7.  Stub code for using the syscall looks like:
> 
> struct target_pid_set {
>         int num_pids;
>         pid_t *target_pids;
>         unsigned long flags;
> };
> 
>         register unsigned long int __r2 asm ("2") = (unsigned long int)(stack);\
>         register unsigned long int __r3 asm ("3") = (unsigned long int)(flags);\
>         register unsigned long int __r4 asm ("4") = (unsigned long int)(NULL); \
>         register unsigned long int __r5 asm ("5") = (unsigned long int)(NULL); \
>         register unsigned long int __r6 asm ("6") = (unsigned long int)(NULL); \
>         register unsigned long int __r7 asm ("7") = (unsigned long int)(setp); \
>         register unsigned long int __result asm ("2"); \
>         __asm__ __volatile__( \
>                 " lghi %%r1,332\n" \
>                 " svc 0\n" \
>                 : "=d" (__result) \
>                 : "0" (__r2), "d" (__r3), \
>                   "d" (__r4), "d" (__r5), "d" (__r6), "d" (__r7) \
>                 : "1", "cc", "memory" \
>         ); \
>                 __result; \
>         })
> 
>         struct target_pid_set pid_set;
>         int pids[1] = { 19799 };
>         pid_set.num_pids = 1;
>         pid_set.target_pids = &pids[0];
>         pid_set.flags = 0;
> 
>         rc = do_clone_with_pids(topstack, clone_flags, setp);
> 	if (rc == 0)
> 		printf("Child\n");
> 	else if (rc > 0)
> 		printf("Parent: child pid %d\n", rc);
> 	else
> 		printf("Error %d\n", rc);
> 
> Signed-off-by: Serge E. Hallyn <serue at us.ibm.com>
> ---
>  arch/s390/include/asm/unistd.h    |    3 ++-
>  arch/s390/kernel/compat_wrapper.S |   10 ++++++++++
>  arch/s390/kernel/process.c        |   19 +++++++++++++++++++
>  arch/s390/kernel/syscalls.S       |    1 +
>  4 files changed, 32 insertions(+), 1 deletions(-)
> 
> diff --git a/arch/s390/include/asm/unistd.h b/arch/s390/include/asm/unistd.h
> index 3d22f17..d2facab 100644
> --- a/arch/s390/include/asm/unistd.h
> +++ b/arch/s390/include/asm/unistd.h
> @@ -269,7 +269,8 @@
>  #define	__NR_pwritev		329
>  #define __NR_checkpoint		330
>  #define __NR_restart		331
> -#define NR_syscalls 332
> +#define __NR_clone_with_pids	332
> +#define NR_syscalls 333
>  
>  /* 
>   * There are some system calls that are not present on 64 bit, some
> diff --git a/arch/s390/kernel/compat_wrapper.S b/arch/s390/kernel/compat_wrapper.S
> index c2228b2..bf13315 100644
> --- a/arch/s390/kernel/compat_wrapper.S
> +++ b/arch/s390/kernel/compat_wrapper.S
> @@ -1837,3 +1837,13 @@ sys_restore_wrapper:
>  	lgfr	%r3,%r3			# int
>  	llgfr	%r4,%r4			# unsigned long
>  	jg	compat_sys_restore
> +
> +	.globl sys_clone_with_pids_wrapper
> +sys_clone_with_pids_wrapper:
> +	llgfr	%r2,%r2			# unsigned long
> +	llgfr	%r3,%r3			# unsigned long
> +	llgtr	%r4,%r4			# int *
> +	llgtr	%r5,%r5			# int *
> +	llgtr	%r6,%r6			# void *
> +	llgtr	%r7,%r7			# void *
> +	jg	compat_sys_clone_with_pids
> diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c
> index a3acd8e..fa187bf 100644
> --- a/arch/s390/kernel/process.c
> +++ b/arch/s390/kernel/process.c
> @@ -246,6 +246,25 @@ SYSCALL_DEFINE0(clone)
>  		       parent_tidptr, child_tidptr);
>  }
>  
> +SYSCALL_DEFINE0(clone_with_pids)
> +{
> +	struct pt_regs *regs = task_pt_regs(current);
> +	unsigned long clone_flags;
> +	unsigned long newsp;
> +	int __user *parent_tidptr, *child_tidptr;
> +	void __user *upid_setp;
> +
> +	clone_flags = regs->gprs[3];
> +	newsp = regs->orig_gpr2;
> +	parent_tidptr = (int __user *) regs->gprs[4];
> +	child_tidptr = (int __user *) regs->gprs[5];
> +	upid_setp = (void __user *) regs->gprs[7];
> +	if (!newsp)
> +		newsp = regs->gprs[15];
> +	return do_fork_with_pids(clone_flags, newsp, regs, 0, parent_tidptr,
> +			child_tidptr, upid_setp);
> +}
> +
>  /*
>   * This is trivial, and on the face of it looks like it
>   * could equally well be done in user mode.
> diff --git a/arch/s390/kernel/syscalls.S b/arch/s390/kernel/syscalls.S
> index e755e93..1d638f5 100644
> --- a/arch/s390/kernel/syscalls.S
> +++ b/arch/s390/kernel/syscalls.S
> @@ -340,3 +340,4 @@ SYSCALL(sys_preadv,sys_preadv,compat_sys_preadv_wrapper)
>  SYSCALL(sys_pwritev,sys_pwritev,compat_sys_pwritev_wrapper)
>  SYSCALL(sys_checkpoint,sys_checkpoint,sys_checkpoint_wrapper) /* 330 */
>  SYSCALL(sys_restart,sys_restart,sys_restore_wrapper)
> +SYSCALL(sys_clone_with_pids,sys_clone_with_pids,sys_clone_with_pids_wrapper)
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