On 26.10.17 20:52, Collin L. Walling wrote:
> The sclp console in the s390 bios writes raw data,
> leading console emulators (such as virsh console) to
> treat a new line ('\n') as just a new line instead
> of as a Unix line feed. Because of this, output
> appears in a "stair case" pattern.
>
> Let's print \r\n on every occurrence of a new line
> in the string passed to write to amend this issue.
>
> This is in sync with the guest Linux code in
> drivers/s390/char/sclp_vt220.c which also does a line feed
> conversion in the console part of the driver.
>
> This fixes the s390-ccw and s390-netboot output like
> $ virsh start test --console
> Domain test started
> Connected to domain test
> Escape character is ^]
> Network boot starting...
> Using MAC address: 02:01:02:03:04:05
> Requesting
> information via DHCP: 010
>
> Signed-off-by: Collin L. Walling <wall...@linux.vnet.ibm.com>
> Signed-off-by: Christian Borntraeger <borntrae...@de.ibm.com>
> ---
> pc-bios/s390-ccw/sclp.c | 16 +++++++++++++---
> 1 file changed, 13 insertions(+), 3 deletions(-)
>
> diff --git a/pc-bios/s390-ccw/sclp.c b/pc-bios/s390-ccw/sclp.c
> index 486fce1..f8ad5ae 100644
> --- a/pc-bios/s390-ccw/sclp.c
> +++ b/pc-bios/s390-ccw/sclp.c
> @@ -68,17 +68,27 @@ void sclp_setup(void)
> long write(int fd, const void *str, size_t len)
> {
> WriteEventData *sccb = (void *)_sccb;
> + const char *p = str;
> + size_t data_len = 0;
> + size_t i;
>
> if (fd != 1 && fd != 2) {
> return -EIO;
> }
>
> - sccb->h.length = sizeof(WriteEventData) + len;
> + for (i = len; i > 0; i--) {
Where did the bounds check go? If you write(max) before, you were
writing max bytes. If you do it now, you end up writing max + n bytes
and potentially overflow the array, no?
Alex
> + if (*p == '\n') {
> + sccb->data[data_len++] = '\r';
> + }
> + sccb->data[data_len++] = *p;
> + p++;
> + }
> +
> + sccb->h.length = sizeof(WriteEventData) + data_len;
> sccb->h.function_code = SCLP_FC_NORMAL_WRITE;
> - sccb->ebh.length = sizeof(EventBufferHeader) + len;
> + sccb->ebh.length = sizeof(EventBufferHeader) + data_len;
> sccb->ebh.type = SCLP_EVENT_ASCII_CONSOLE_DATA;
> sccb->ebh.flags = 0;
> - memcpy(sccb->data, str, len);
>
> sclp_service_call(SCLP_CMD_WRITE_EVENT_DATA, sccb);
>
>
