qemu/pc-bios/s390-ccw/sclp.c
Claudio Imbrenda f24ec9fead pc-bios/s390-ccw: fix sclp_get_loadparm_ascii
The existing s390 bios gets the LOADPARM information from the system using
an SCLP call that specifies a buffer length too small to contain all the
output.

The recent fixes in the SCLP code have exposed this bug, since now the
SCLP call will return an error (as per architecture) instead of
writing partially and completing successfully.

The solution is simply to specify the full page length as the SCCB
length instead of a smaller size.

Fixes: 832be0d8a3 ("s390x: sclp: Report insufficient SCCB length")
Fixes: 9a22473c70 ("pc-bios/s390-ccw: get LOADPARM stored in SCP Read Info")

Reported-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Message-Id: <1574944437-31182-1-git-send-email-imbrenda@linux.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Tested-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Tested-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
2019-11-29 09:16:02 +01:00

139 lines
3.7 KiB
C

/*
* SCLP ASCII access driver
*
* Copyright (c) 2013 Alexander Graf <agraf@suse.de>
*
* This work is licensed under the terms of the GNU GPL, version 2 or (at
* your option) any later version. See the COPYING file in the top-level
* directory.
*/
#include "libc.h"
#include "s390-ccw.h"
#include "sclp.h"
long write(int fd, const void *str, size_t len);
static char _sccb[PAGE_SIZE] __attribute__((__aligned__(4096)));
const unsigned char ebc2asc[256] =
/* 0123456789abcdef0123456789abcdef */
"................................" /* 1F */
"................................" /* 3F */
" ...........<(+|&.........!$*);." /* 5F first.chr.here.is.real.space */
"-/.........,%_>?.........`:#@'=\""/* 7F */
".abcdefghi.......jklmnopqr......" /* 9F */
"..stuvwxyz......................" /* BF */
".ABCDEFGHI.......JKLMNOPQR......" /* DF */
"..STUVWXYZ......0123456789......";/* FF */
/* Perform service call. Return 0 on success, non-zero otherwise. */
static int sclp_service_call(unsigned int command, void *sccb)
{
int cc;
asm volatile(
" .insn rre,0xb2200000,%1,%2\n" /* servc %1,%2 */
" ipm %0\n"
" srl %0,28"
: "=&d" (cc) : "d" (command), "a" (__pa(sccb))
: "cc", "memory");
consume_sclp_int();
if (cc == 3)
return -EIO;
if (cc == 2)
return -EBUSY;
return 0;
}
void sclp_set_write_mask(uint32_t receive_mask, uint32_t send_mask)
{
WriteEventMask *sccb = (void *)_sccb;
sccb->h.length = sizeof(WriteEventMask);
sccb->mask_length = sizeof(unsigned int);
sccb->cp_receive_mask = receive_mask;
sccb->cp_send_mask = send_mask;
sclp_service_call(SCLP_CMD_WRITE_EVENT_MASK, sccb);
}
void sclp_setup(void)
{
sclp_set_write_mask(0, SCLP_EVENT_MASK_MSG_ASCII);
}
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;
}
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) + data_len;
sccb->ebh.type = SCLP_EVENT_ASCII_CONSOLE_DATA;
sccb->ebh.flags = 0;
sclp_service_call(SCLP_CMD_WRITE_EVENT_DATA, sccb);
return len;
}
void sclp_print(const char *str)
{
write(1, str, strlen(str));
}
void sclp_get_loadparm_ascii(char *loadparm)
{
ReadInfo *sccb = (void *)_sccb;
memset((char *)_sccb, 0, sizeof(ReadInfo));
sccb->h.length = SCCB_SIZE;
if (!sclp_service_call(SCLP_CMDW_READ_SCP_INFO, sccb)) {
ebcdic_to_ascii((char *) sccb->loadparm, loadparm, LOADPARM_LEN);
}
}
int sclp_read(char *str, size_t count)
{
ReadEventData *sccb = (void *)_sccb;
char *buf = (char *)(&sccb->ebh) + 7;
/* If count exceeds max buffer size, then restrict it to the max size */
if (count > SCCB_SIZE - 8) {
count = SCCB_SIZE - 8;
}
sccb->h.length = SCCB_SIZE;
sccb->h.function_code = SCLP_UNCONDITIONAL_READ;
sclp_service_call(SCLP_CMD_READ_EVENT_DATA, sccb);
memcpy(str, buf, count);
return sccb->ebh.length - 7;
}