Re: [BUGFIX][PATCH 3/4] xg_read_mem: Report on error.

[Mukesh Rathor <mukesh.rathor@oracle.com>]

On Sat,  4 Jan 2014 12:52:15 -0500
Don Slutz <dslutz@verizon.com> wrote:

> I had coded this with XGERR, but gdb will try to read memory without
> a direct request from the user.  So the error message can be
> confusing.
> 
> Signed-off-by: Don Slutz <dslutz@verizon.com>

Acked-by: Mukesh Rathor <mukesh.rathor@oracle.com>

> ---
>  tools/debugger/gdbsx/xg/xg_main.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/tools/debugger/gdbsx/xg/xg_main.c
> b/tools/debugger/gdbsx/xg/xg_main.c index 5736b86..a192478 100644
> --- a/tools/debugger/gdbsx/xg/xg_main.c
> +++ b/tools/debugger/gdbsx/xg/xg_main.c
> @@ -775,7 +775,7 @@ xg_read_mem(uint64_t guestva, char *tobuf, int
> tobuf_len, uint64_t pgd3val) {
>      struct xen_domctl_gdbsx_memio *iop = &domctl.u.gdbsx_guest_memio;
>      union {uint64_t llbuf8; char buf8[8];} u = {0};
> -    int i;
> +    int i, rc;
>  
>      XGTRC("E:gva:%llx tobuf:%lx len:%d\n", guestva, tobuf,
> tobuf_len); 
> @@ -786,7 +786,9 @@ xg_read_mem(uint64_t guestva, char *tobuf, int
> tobuf_len, uint64_t pgd3val) iop->len = tobuf_len;
>      iop->gwr = 0;       /* not writing to guest */
>  
> -    _domctl_hcall(XEN_DOMCTL_gdbsx_guestmemio, tobuf, tobuf_len);
> +    if ( (rc = _domctl_hcall(XEN_DOMCTL_gdbsx_guestmemio, tobuf,
> tobuf_len)) )
> +        XGTRC("ERROR: failed to read %d bytes. errno:%d rc:%d\n",
> +              iop->remain, errno, rc);
>  
>      for(i=0; i < XGMIN(8, tobuf_len); u.buf8[i]=tobuf[i], i++);
>      XGTRC("X:remain:%d buf8:0x%llx\n", iop->remain, u.llbuf8);