diff mbox

[v4] s390-ccw: print carriage return with new lines

Message ID 1509120893-28054-1-git-send-email-walling@linux.vnet.ibm.com (mailing list archive)
State New, archived
Headers show

Commit Message

Collin L. Walling Oct. 27, 2017, 4:14 p.m. UTC
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 <walling@linux.vnet.ibm.com>
---
 pc-bios/s390-ccw/sclp.c | 24 +++++++++++++++++++++---
 1 file changed, 21 insertions(+), 3 deletions(-)

Comments

Halil Pasic Oct. 27, 2017, 5:40 p.m. UTC | #1
On 10/27/2017 06:14 PM, 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 <walling@linux.vnet.ibm.com>

Reviewed-by: Halil Pasic <pasic@linux.vnet.ibm.com>

> ---
>  pc-bios/s390-ccw/sclp.c | 24 +++++++++++++++++++++---
>  1 file changed, 21 insertions(+), 3 deletions(-)
> 
> diff --git a/pc-bios/s390-ccw/sclp.c b/pc-bios/s390-ccw/sclp.c
> index 486fce1..e6a0898 100644
> --- a/pc-bios/s390-ccw/sclp.c
> +++ b/pc-bios/s390-ccw/sclp.c
> @@ -68,17 +68,35 @@ 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 = 0; i < len; i++) {
> +        if ((data_len + 1) >= SCCB_DATA_LEN) {
> +            /* We would overflow the sccb buffer, abort early */
> +            len = i;
> +            break;
> +        }
> +
> +        if (*p == '\n') {
> +            /* Terminal emulators might need \r\n, so generate it */
> +            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);
>
Farhan Ali Oct. 27, 2017, 8:25 p.m. UTC | #2
On 10/27/2017 12:14 PM, 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 <walling@linux.vnet.ibm.com>
> ---
>  pc-bios/s390-ccw/sclp.c | 24 +++++++++++++++++++++---
>  1 file changed, 21 insertions(+), 3 deletions(-)
>
> diff --git a/pc-bios/s390-ccw/sclp.c b/pc-bios/s390-ccw/sclp.c
> index 486fce1..e6a0898 100644
> --- a/pc-bios/s390-ccw/sclp.c
> +++ b/pc-bios/s390-ccw/sclp.c
> @@ -68,17 +68,35 @@ 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 = 0; i < len; i++) {
> +        if ((data_len + 1) >= SCCB_DATA_LEN) {
> +            /* We would overflow the sccb buffer, abort early */
> +            len = i;
> +            break;
> +        }
> +
> +        if (*p == '\n') {
> +            /* Terminal emulators might need \r\n, so generate it */
> +            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);
>
Reviewed-by: Farhan Ali <alifm@linux.vnet.ibm.com>
Cornelia Huck Oct. 28, 2017, 6:58 a.m. UTC | #3
On Fri, 27 Oct 2017 12:14:53 -0400
"Collin L. Walling" <walling@linux.vnet.ibm.com> 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 <walling@linux.vnet.ibm.com>
> ---
>  pc-bios/s390-ccw/sclp.c | 24 +++++++++++++++++++++---
>  1 file changed, 21 insertions(+), 3 deletions(-)

Acked-by: Cornelia Huck <cohuck@redhat.com>
Alexander Graf Oct. 29, 2017, 1:58 a.m. UTC | #4
On 27.10.17 18:14, 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 <walling@linux.vnet.ibm.com>
> ---
>  pc-bios/s390-ccw/sclp.c | 24 +++++++++++++++++++++---
>  1 file changed, 21 insertions(+), 3 deletions(-)
> 
> diff --git a/pc-bios/s390-ccw/sclp.c b/pc-bios/s390-ccw/sclp.c
> index 486fce1..e6a0898 100644
> --- a/pc-bios/s390-ccw/sclp.c
> +++ b/pc-bios/s390-ccw/sclp.c
> @@ -68,17 +68,35 @@ 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 = 0; i < len; i++) {
> +        if ((data_len + 1) >= SCCB_DATA_LEN) {
> +            /* We would overflow the sccb buffer, abort early */
> +            len = i;
> +            break;
> +        }
> +
> +        if (*p == '\n') {
> +            /* Terminal emulators might need \r\n, so generate it */
> +            sccb->data[data_len++] = '\r';
> +        }
> +
> +        sccb->data[data_len++] = *p;
> +        p++;

I would probably replace this with str[i] to make it slightly more
readable, but that's just personal preference I think. The resulting
assembly should be identical with any recent compiler.


Reviewed-by: Alexander Graf <agraf@suse.de>

Alex
Christian Borntraeger Oct. 30, 2017, 8:08 a.m. UTC | #5
On 10/27/2017 06:14 PM, 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 <walling@linux.vnet.ibm.com>

Thanks, applied.
diff mbox

Patch

diff --git a/pc-bios/s390-ccw/sclp.c b/pc-bios/s390-ccw/sclp.c
index 486fce1..e6a0898 100644
--- a/pc-bios/s390-ccw/sclp.c
+++ b/pc-bios/s390-ccw/sclp.c
@@ -68,17 +68,35 @@  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 = 0; i < len; i++) {
+        if ((data_len + 1) >= SCCB_DATA_LEN) {
+            /* We would overflow the sccb buffer, abort early */
+            len = i;
+            break;
+        }
+
+        if (*p == '\n') {
+            /* Terminal emulators might need \r\n, so generate it */
+            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);