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7a2f91441b
Register variables initialized using arithmetic. That leads to
kasan instrumentaton code corrupting the registers contents.
Follow GCC guidlines and use temporary variables for assigning
init values to register variables.
Fixes: 94c12cc7d1 ("[S390] Inline assembly cleanup.")
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Link: https://gcc.gnu.org/onlinedocs/gcc-10.2.0/gcc/Local-Register-Variables.html
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
113 lines
2.7 KiB
C
113 lines
2.7 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* S390 version
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* Copyright IBM Corp. 1999, 2007
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* Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
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* Christian Borntraeger (cborntra@de.ibm.com),
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*/
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#define KMSG_COMPONENT "cpcmd"
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#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
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#include <linux/kernel.h>
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#include <linux/export.h>
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#include <linux/slab.h>
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#include <linux/spinlock.h>
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#include <linux/stddef.h>
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#include <linux/string.h>
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#include <linux/mm.h>
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#include <asm/diag.h>
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#include <asm/ebcdic.h>
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#include <asm/cpcmd.h>
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#include <asm/io.h>
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static DEFINE_SPINLOCK(cpcmd_lock);
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static char cpcmd_buf[241];
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static int diag8_noresponse(int cmdlen)
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{
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register unsigned long reg2 asm ("2") = (addr_t) cpcmd_buf;
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register unsigned long reg3 asm ("3") = cmdlen;
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asm volatile(
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" diag %1,%0,0x8\n"
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: "+d" (reg3) : "d" (reg2) : "cc");
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return reg3;
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}
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static int diag8_response(int cmdlen, char *response, int *rlen)
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{
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unsigned long _cmdlen = cmdlen | 0x40000000L;
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unsigned long _rlen = *rlen;
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register unsigned long reg2 asm ("2") = (addr_t) cpcmd_buf;
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register unsigned long reg3 asm ("3") = (addr_t) response;
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register unsigned long reg4 asm ("4") = _cmdlen;
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register unsigned long reg5 asm ("5") = _rlen;
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asm volatile(
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" diag %2,%0,0x8\n"
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" brc 8,1f\n"
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" agr %1,%4\n"
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"1:\n"
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: "+d" (reg4), "+d" (reg5)
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: "d" (reg2), "d" (reg3), "d" (*rlen) : "cc");
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*rlen = reg5;
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return reg4;
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}
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/*
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* __cpcmd has some restrictions over cpcmd
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* - __cpcmd is unlocked and therefore not SMP-safe
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*/
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int __cpcmd(const char *cmd, char *response, int rlen, int *response_code)
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{
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int cmdlen;
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int rc;
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int response_len;
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cmdlen = strlen(cmd);
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BUG_ON(cmdlen > 240);
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memcpy(cpcmd_buf, cmd, cmdlen);
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ASCEBC(cpcmd_buf, cmdlen);
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diag_stat_inc(DIAG_STAT_X008);
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if (response) {
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memset(response, 0, rlen);
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response_len = rlen;
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rc = diag8_response(cmdlen, response, &rlen);
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EBCASC(response, response_len);
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} else {
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rc = diag8_noresponse(cmdlen);
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}
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if (response_code)
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*response_code = rc;
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return rlen;
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}
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EXPORT_SYMBOL(__cpcmd);
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int cpcmd(const char *cmd, char *response, int rlen, int *response_code)
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{
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unsigned long flags;
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char *lowbuf;
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int len;
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if (is_vmalloc_or_module_addr(response)) {
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lowbuf = kmalloc(rlen, GFP_KERNEL);
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if (!lowbuf) {
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pr_warn("The cpcmd kernel function failed to allocate a response buffer\n");
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return -ENOMEM;
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}
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spin_lock_irqsave(&cpcmd_lock, flags);
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len = __cpcmd(cmd, lowbuf, rlen, response_code);
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spin_unlock_irqrestore(&cpcmd_lock, flags);
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memcpy(response, lowbuf, rlen);
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kfree(lowbuf);
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} else {
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spin_lock_irqsave(&cpcmd_lock, flags);
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len = __cpcmd(cmd, response, rlen, response_code);
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spin_unlock_irqrestore(&cpcmd_lock, flags);
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}
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return len;
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}
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EXPORT_SYMBOL(cpcmd);
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