On 10/20/2017 12:25 PM, Christian Borntraeger wrote:
> From: "Collin L. Walling" <wall...@linux.vnet.ibm.com>
>
> 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
>
The check for buffer overflow was not there previously, or?
Maybe integrate that in the commit message too.
> Signed-off-by: Collin L. Walling <wall...@linux.vnet.ibm.com>
> Signed-off-by: Christian Borntraeger <borntrae...@de.ibm.com>
> ---
> pc-bios/s390-ccw/s390-ccw.h | 3 +++
> pc-bios/s390-ccw/sclp.c | 17 ++++++++++++++---
> 2 files changed, 17 insertions(+), 3 deletions(-)
>
> diff --git a/pc-bios/s390-ccw/s390-ccw.h b/pc-bios/s390-ccw/s390-ccw.h
> index 25d4d21..a8bd204 100644
> --- a/pc-bios/s390-ccw/s390-ccw.h
> +++ b/pc-bios/s390-ccw/s390-ccw.h
> @@ -33,6 +33,9 @@ typedef unsigned long long __u64;
> #ifndef EBUSY
> #define EBUSY 2
> #endif
> +#ifndef EFBIG
> +#define EFBIG 3
> +#endif
> #ifndef NULL
> #define NULL 0
> #endif
> diff --git a/pc-bios/s390-ccw/sclp.c b/pc-bios/s390-ccw/sclp.c
> index b1fc8ff..4795259 100644
> --- a/pc-bios/s390-ccw/sclp.c
> +++ b/pc-bios/s390-ccw/sclp.c
> @@ -76,17 +76,28 @@ static int _strlen(const char *str)
> long write(int fd, const void *str, size_t len)
> {
> WriteEventData *sccb = (void *)_sccb;
> + const char *p;
> + size_t data_len = 0;
>
> if (fd != 1 && fd != 2) {
> return -EIO;
> }
>
> - sccb->h.length = sizeof(WriteEventData) + len;
> + for (p = str; *p; ++p) {
> + if (data_len > SCCB_DATA_LEN - 1) {
> + return -EFBIG;
> + }
We could also do a partial write or do more that one
sclp_service_call calls.
I don't think EFBIG is entirely correct here. From the man page:
"""
EFBIG An attempt was made to write a file that exceeds the implementa-
tion-defined maximum file size or the process’s file size limit,
or to write at a position past the maximum allowed offset.
"""
That's not what we have here IMHO.
> + if (*p == '\n') {
> + sccb->data[data_len++] = '\r';
> + }
> + sccb->data[data_len++] = *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);
>
Otherwise LGTM
Halil
