Re: semop()/semtimedop() sembuf argument printing in strace

[Dmitry V. L. <ld...@al...>]

Hi,

On Wed, Sep 30, 2009 at 05:59:07PM +0200, Jakub Bogusz wrote:
> 
> the attached patch adds pretty printing of sembuf argument and flags to
> semop() and semtimedop() syscalls.

Thank you for the patch.  See my comments below.

> --- strace-4.5.18/ipc.c.orig	2007-01-15 21:25:52.000000000 +0100
> +++ strace-4.5.18/ipc.c	2009-09-30 17:48:38.080610937 +0200
[...]
> @@ -273,14 +279,34 @@
>  int sys_semop(tcp)
>  struct tcb *tcp;
>  {
> +	int i;
> +
>  	if (entering(tcp)) {
>  		tprintf("%lu", tcp->u_arg[0]);
>  		if (indirect_ipccall(tcp)) {
> -			tprintf(", %#lx", tcp->u_arg[3]);
> -			tprintf(", %lu", tcp->u_arg[1]);
> +			tprintf(", %#lx {", tcp->u_arg[3]);
> +			for(i = 0; i < tcp->u_arg[1]; i++) {
> +				struct sembuf sb;
> +				umove(tcp, tcp->u_arg[3]+i*sizeof(struct sembuf), &sb);

umove() return code usually have to be taken into account, especially
when umove() arguments come from user input.

> +				if(i != 0)
> +					tprintf(", ");
> +				tprintf("{%u, %d, ", sb.sem_num, sb.sem_op);
> +				printflags(semop_flags, sb.sem_flg, "SEM_???");
> +				tprintf("}");
> +			}
> +			tprintf("}, %lu", tcp->u_arg[1]);
>  		} else {
> -			tprintf(", %#lx", tcp->u_arg[1]);
> -			tprintf(", %lu", tcp->u_arg[2]);
> +			tprintf(", %#lx {", tcp->u_arg[1]);
> +			for(i = 0; i < tcp->u_arg[2]; i++) {
> +				struct sembuf sb;
> +				umove(tcp, tcp->u_arg[1]+i*sizeof(struct sembuf), &sb);

Likewise.


-- 
ldv