Update AArch64 strace to also support tracing 32-bit ARM binaries

[Denys Vlasenko]

On 11/10/2012 12:24 PM, Steve McIntyre wrote:
> @@ -916,6 +923,29 @@ get_scno(struct tcb *tcp)
>  		if (upeek(tcp, PT_R15, &scno) < 0)
>  			return -1;
>  	}
> +#elif defined(AARCH64)
> +	struct iovec io;
> +	char buf[sizeof(aarch64_regs)];
> +	io.iov_base = &buf;
> +	io.iov_len = sizeof(aarch64_regs);
> +	if (ptrace(PTRACE_GETREGSET, tcp->pid, NT_PRSTATUS, (void *)&io) == -1)
> +		return -1;
> +	switch (io.iov_len) {
> +		case sizeof(aarch64_regs):
> +			/* We are in 64-bit mode */
> +			memcpy(&aarch64_regs, buf, sizeof(aarch64_regs));
> +			scno = aarch64_regs.regs[8];
> +			update_personality(tcp, 1);
> +			break;
> +		case sizeof(regs):
> +			/* We are in 32-bit mode */
> +			memcpy(&regs, buf, sizeof(regs));
> +			scno = regs.uregs[7];
> +			update_personality(tcp, 0);
> +			break;
> +		default:
> +			return -1;
> +	}
>  #elif defined(ARM)
>  	/* Read complete register set in one go. */
>  	if (ptrace(PTRACE_GETREGS, tcp->pid, NULL, (void *)&regs) == -1)

You check and set personality in get_scno(). Ok.


> @@ -1655,16 +1681,31 @@ get_syscall_result(struct tcb *tcp)
>  		return -1;
>  	if (upeek(tcp, PT_R10, &r10) < 0)
>  		return -1;
> -#elif defined(ARM)
> -	/* Read complete register set in one go. */
> -	if (ptrace(PTRACE_GETREGS, tcp->pid, NULL, (void *)&regs) == -1)
> -		return -1;
>  #elif defined(AARCH64)
>  	struct iovec io;
> -	io.iov_base = ®s;
> -	io.iov_len = sizeof(regs);
> +	char buf[sizeof(aarch64_regs)];
> +	io.iov_base = &buf;
> +	io.iov_len = sizeof(aarch64_regs);
>  	if (ptrace(PTRACE_GETREGSET, tcp->pid, NT_PRSTATUS, (void *)&io) == -1)
>  		return -1;
> +	switch (io.iov_len) {
> +		case sizeof(aarch64_regs):
> +			/* We are in 64-bit mode */		
> +			memcpy(&aarch64_regs, buf, sizeof(aarch64_regs));
> +			update_personality(tcp, 1);
> +			break;
> +		case sizeof(regs):
> +			/* We are in 32-bit mode */		
> +			memcpy(&regs, buf, sizeof(regs));
> +			update_personality(tcp, 0);
> +			break;
> +		default:
> +			return -1;
> +	}

No other architecture calls update_personality() on syscall exit
(get_syscall_result() is called, naturally, only on exit).

I think these update_personality() calls can be safely removed.

-- 
vda