// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Unaligned memory access handler
*
* Copyright (C) 2001 Randolph Chung <tausq@debian.org>
* Copyright (C) 2022 Helge Deller <deller@gmx.de>
* Significantly tweaked by LaMont Jones <lamont@debian.org>
*/
#include <linux/sched/signal.h>
#include <linux/signal.h>
#include <linux/ratelimit.h>
#include <linux/uaccess.h>
#include <linux/sysctl.h>
#include <asm/unaligned.h>
#include <asm/hardirq.h>
#include <asm/traps.h>
/* #define DEBUG_UNALIGNED 1 */
#ifdef DEBUG_UNALIGNED
#define DPRINTF(fmt, args...) do { printk(KERN_DEBUG "%s:%d:%s ", __FILE__, __LINE__, __func__ ); printk(KERN_DEBUG fmt, ##args ); } while (0)
#else
#define DPRINTF(fmt, args...)
#endif
#define RFMT "%#08lx"
/* 1111 1100 0000 0000 0001 0011 1100 0000 */
#define OPCODE1(a,b,c) ((a)<<26|(b)<<12|(c)<<6)
#define OPCODE2(a,b) ((a)<<26|(b)<<1)
#define OPCODE3(a,b) ((a)<<26|(b)<<2)
#define OPCODE4(a) ((a)<<26)
#define OPCODE1_MASK OPCODE1(0x3f,1,0xf)
#define OPCODE2_MASK OPCODE2(0x3f,1)
#define OPCODE3_MASK OPCODE3(0x3f,1)
#define OPCODE4_MASK OPCODE4(0x3f)
/* skip LDB - never unaligned (index) */
#define OPCODE_LDH_I OPCODE1(0x03,0,0x1)
#define OPCODE_LDW_I OPCODE1(0x03,0,0x2)
#define OPCODE_LDD_I OPCODE1(0x03,0,0x3)
#define OPCODE_LDDA_I OPCODE1(0x03,0,0x4)
#define OPCODE_LDCD_I OPCODE1(0x03,0,0x5)
#define OPCODE_LDWA_I OPCODE1(0x03,0,0x6)
#define OPCODE_LDCW_I OPCODE1(0x03,0,0x7)
/* skip LDB - never unaligned (short) */
#define OPCODE_LDH_S OPCODE1(0x03,1,0x1)
#define OPCODE_LDW_S OPCODE1(0x03,1,0x2)
#define OPCODE_LDD_S OPCODE1(0x03,1,0x3)
#define OPCODE_LDDA_S OPCODE1(0x03,1,0x4)
#define OPCODE_LDCD_S OPCODE1(0x03,1,0x5)
#define OPCODE_LDWA_S OPCODE1(0x03,1,0x6)
#define OPCODE_LDCW_S OPCODE1(0x03,1,0x7)
/* skip STB - never unaligned */
#define OPCODE_STH OPCODE1(0x03,1,0x9)
#define OPCODE_STW OPCODE1(0x03,1,0xa)
#define OPCODE_STD OPCODE1(0x03,1,0xb)
/* skip STBY - never unaligned */
/* skip STDBY - never unaligned */
#define OPCODE_STWA OPCODE1(0x03,1,0xe)
#define OPCODE_STDA OPCODE1(0x03,1,0xf)
#define OPCODE_FLDWX OPCODE1(0x09,0,0x0)
#define OPCODE_FLDWXR OPCODE1(0x09,0,0x1)
#define OPCODE_FSTWX OPCODE1(0x09,0,0x8)
#define OPCODE_FSTWXR OPCODE1(0x09,0,0x9)
#define OPCODE_FLDWS OPCODE1(0x09,1,0x0)
#define OPCODE_FLDWSR OPCODE1(0x09,1,0x1)
#define OPCODE_FSTWS OPCODE1(0x09,1,0x8)
#define OPCODE_FSTWSR OPCODE1(0x09,1,0x9)
#define OPCODE_FLDDX OPCODE1(0x0b,0,0x0)
#define OPCODE_FSTDX OPCODE1(0x0b,0,0x8)
#define OPCODE_FLDDS OPCODE1(0x0b,1,0x0)
#define OPCODE_FSTDS OPCODE1(0x0b,1,0x8)
#define OPCODE_LDD_L OPCODE2(0x14,0)
#define OPCODE_FLDD_L OPCODE2(0x14,1)
#define OPCODE_STD_L OPCODE2(0x1c,0)
#define OPCODE_FSTD_L OPCODE2(0x1c,1)
#define OPCODE_LDW_M OPCODE3(0x17,1)
#define OPCODE_FLDW_L OPCODE3(0x17,0)
#define OPCODE_FSTW_L OPCODE3(0x1f,0)
#define OPCODE_STW_M OPCODE3(0x1f,1)
#define OPCODE_LDH_L OPCODE4(0x11)
#define OPCODE_LDW_L OPCODE4(0x12)
#define OPCODE_LDWM OPCODE4(0x13)
#define OPCODE_STH_L OPCODE4(0x19)
#define OPCODE_STW_L OPCODE4(0x1A)
#define OPCODE_STWM OPCODE4(0x1B)
#define MAJOR_OP(i) (((i)>>26)&0x3f)
#define R1(i) (((i)>>21)&0x1f)
#define R2(i) (((i)>>16)&0x1f)
#define R3(i) ((i)&0x1f)
#define FR3(i) ((((i)&0x1f)<<1)|(((i)>>6)&1))
#define IM(i,n) (((i)>>1&((1<<(n-1))-1))|((i)&1?((0-1L)<<(n-1)):0))
#define IM5_2(i) IM((i)>>16,5)
#define IM5_3(i) IM((i),5)
#define IM14(i) IM((i),14)
#define ERR_NOTHANDLED -1
int unaligned_enabled __read_mostly = 1;
static int emulate_ldh(struct pt_regs *regs, int toreg)
{
unsigned long saddr = regs->ior;
unsigned long val = 0, temp1;
ASM_EXCEPTIONTABLE_VAR(ret);
DPRINTF("load " RFMT ":" RFMT " to r%d for 2 bytes\n",
regs->isr, regs->ior, toreg);
__asm__ __volatile__ (
" mtsp %4, %%sr1\n"
"1: ldbs 0(%%sr1,%3), %2\n"
"2: ldbs 1(%%sr1,%3), %0\n"
" depw %2, 23, 24, %0\n"
"3: \n"
ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 3b)
ASM_EXCEPTIONTABLE_ENTRY_EFAULT(2b, 3b)
: "+r" (val), "+r" (ret), "=&r" (temp1)
: "r" (saddr), "r" (regs->isr) );
DPRINTF("val = " RFMT "\n", val);
if (toreg)
regs->gr[toreg] = val;
return ret;
}
static int emulate_ldw(struct pt_regs *regs, int toreg, int flop)
{
unsigned long saddr = regs->ior;
unsigned long val = 0, temp1, temp2;
ASM_EXCEPTIONTABLE_VAR(ret);
DPRINTF("load " RFMT ":" RFMT " to r%d for 4 bytes\n",
regs->isr, regs->ior, toreg);
__asm__ __volatile__ (
" zdep %4,28,2,%2\n" /* r19=(ofs&3)*8 */
" mtsp %5, %%sr1\n"
" depw %%r0,31,2,%4\n"
"1: ldw 0(%%sr1,%4),%0\n"
"2: ldw 4(%%sr1,%4),%3\n"
" subi 32,%2,%2\n"
" mtctl %2,11\n"
" vshd %0,%3,%0\n"
"3: \n"
ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 3b)
ASM_EXCEPTIONTABLE_ENTRY_EFAULT(2b, 3b)
: "+r" (val), "+r" (ret), "=&r" (temp1), "=&r" (temp2)
: "r" (saddr), "r" (regs->isr) );
DPRINTF("val = " RFMT "\n", val);
if (flop)
((__u32*)(regs->fr))[toreg] = val;
else if (toreg)
regs->gr[toreg] = val;
return ret;
}
static int emulate_ldd(struct pt_regs *regs, int toreg, int flop)
{
unsigned long saddr = regs->ior;
__u64 val = 0;
ASM_EXCEPTIONTABLE_VAR(ret);
DPRINTF("load " RFMT ":" RFMT " to r%d for 8 bytes\n",
regs->isr, regs->ior, toreg);
if (!IS_ENABLED(CONFIG_64BIT) && !flop)
return ERR_NOTHANDLED;
#ifdef CONFIG_64BIT
__asm__ __volatile__ (
" depd,z %3,60,3,%%r19\n" /* r19=(ofs&7)*8 */
" mtsp %4, %%sr1\n"
" depd %%r0,63,3,%3\n"
"1: ldd 0(%%sr1,%3),%0\n"
"2: ldd 8(%%sr1,%3),%%r20\n"
" subi 64,%%r19,%%r19\n"
" mtsar %%r19\n"
" shrpd %0,%%r20,%%sar,%0\n"
"3: \n"
ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 3b)
ASM_EXCEPTIONTABLE_ENTRY_EFAULT(2b, 3b)
: "=r" (val), "+r" (ret)
: "0" (val), "r" (saddr), "r" (regs->isr)
: "r19", "r20" );
#else
{
unsigned long shift, temp1;
__asm__ __volatile__ (
" zdep %2,29,2,%3\n" /* r19=(ofs&3)*8 */
" mtsp %5, %%sr1\n"
" dep %%r0,31,2,%2\n"
"1: ldw 0(%%sr1,%2),%0\n"
"2: ldw 4(%%sr1,%2),%R0\n"
"3: ldw 8(%%sr1,%2),%4\n"
" subi 32,%3,%3\n"
" mtsar %3\n"
" vshd %0,%R0,%0\n"
" vshd %R0,%4,%R0\n"
"4: \n"
ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 4b)
ASM_EXCEPTIONTABLE_ENTRY_EFAULT(2b, 4b)
ASM_EXCEPTIONTABLE_ENTRY_EFAULT(3b, 4b)
: "+r" (val), "+r" (ret), "+r" (saddr), "=&r" (shift), "=&r" (temp1)
: "r" (regs->isr) );
}
#endif
DPRINTF("val = 0x%llx\n", val);
if (flop)
regs->fr[toreg] = val;
else if (toreg)
regs->gr[toreg] = val;
return ret;
}
static int emulate_sth(struct pt_regs *regs, int frreg)
{
unsigned long val = regs->gr[frreg], temp1;
ASM_EXCEPTIONTABLE_VAR(ret);
if (!frreg)
val = 0;
DPRINTF("store r%d (" RFMT ") to " RFMT ":" RFMT " for 2 bytes\n", frreg,
val, regs->isr, regs->ior);
__asm__ __volatile__ (
" mtsp %4, %%sr1\n"
" extrw,u %2, 23, 8, %1\n"
"1: stb %1, 0(%%sr1, %3)\n"
"2: stb %2, 1(%%sr1, %3)\n"
"3: \n"
ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 3b)
ASM_EXCEPTIONTABLE_ENTRY_EFAULT(2b, 3b)
: "+r" (ret), "=&r" (temp1)
: "r" (val), "r" (regs->ior), "r" (regs->isr) );
return ret;
}
static int emulate_stw(struct pt_regs *regs, int frreg, int flop)
{
unsigned long val;
ASM_EXCEPTIONTABLE_VAR(ret);
if (flop)
val = ((__u32*)(regs->fr))[frreg];
else if (frreg)
val = regs->gr[frreg];
else
val = 0;
DPRINTF("store r%d (" RFMT ") to " RFMT ":" RFMT " for 4 bytes\n", frreg,
val, regs->isr, regs->ior);
__asm__ __volatile__ (
" mtsp %3, %%sr1\n"
" zdep %2, 28, 2, %%r19\n"
" dep %%r0, 31, 2, %2\n"
" mtsar %%r19\n"
" depwi,z -2, %%sar, 32, %%r19\n"
"1: ldw 0(%%sr1,%2),%%r20\n"
"2: ldw 4(%%sr1,%2),%%r21\n"
" vshd %%r0, %1, %%r22\n"
" vshd %1, %%r0, %%r1\n"
" and %%r20, %%r19, %%r20\n"
" andcm %%r21, %%r19, %%r21\n"
" or %%r22, %%r20, %%r20\n"
" or %%r1, %%r21, %%r21\n"
" stw %%r20,0(%%sr1,%2)\n"
" stw %%r21,4(%%sr1,%2)\n"
"3: \n"
ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 3b)
ASM_EXCEPTIONTABLE_ENTRY_EFAULT(2b, 3b)
: "+r" (ret)
: "r" (val), "r" (regs->ior), "r" (regs->isr)
: "r19", "r20", "r21", "r22", "r1" );
return ret;
}
static int emulate_std(struct pt_regs *regs, int frreg, int flop)
{
__u64 val;
ASM_EXCEPTIONTABLE_VAR(ret);
if (flop)
val = regs->fr[frreg];
else if (frreg)
val = regs->gr[frreg];
else
val = 0;
DPRINTF("store r%d (0x%016llx) to " RFMT ":" RFMT " for 8 bytes\n", frreg,
val, regs->isr, regs->ior);
if (!IS_ENABLED(CONFIG_64BIT) && !flop)
return ERR_NOTHANDLED;
#ifdef CONFIG_64BIT
__asm__ __volatile__ (
" mtsp %3, %%sr1\n"
" depd,z %2, 60, 3, %%r19\n"
" depd %%r0, 63, 3, %2\n"
" mtsar %%r19\n"
" depdi,z -2, %%sar, 64, %%r19\n"
"1: ldd 0(%%sr1,%2),%%r20\n"
"2: ldd 8(%%sr1,%2),%%r21\n"
" shrpd %%r0, %1, %%sar, %%r22\n"
" shrpd %1, %%r0, %%sar, %%r1\n"
" and %%r20, %%r19, %%r20\n"
" andcm %%r21, %%r19, %%r21\n"
" or %%r22, %%r20, %%r20\n"
" or %%r1, %%r21, %%r21\n"
"3: std %%r20,0(%%sr1,%2)\n"
"4: std %%r21,8(%%sr1,%2)\n"
"5: \n"
ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 5b)
ASM_EXCEPTIONTABLE_ENTRY_EFAULT(2b, 5b)
ASM_EXCEPTIONTABLE_ENTRY_EFAULT(3b, 5b)
ASM_EXCEPTIONTABLE_ENTRY_EFAULT(4b, 5b)
: "+r" (ret)
: "r" (val), "r" (regs->ior), "r" (regs->isr)
: "r19", "r20", "r21", "r22", "r1" );
#else
{
__asm__ __volatile__ (
" mtsp %3, %%sr1\n"
" zdep %R1, 29, 2, %%r19\n"
" dep %%r0, 31, 2, %2\n"
" mtsar %%r19\n"
" zvdepi -2, 32, %%r19\n"
"1: ldw 0(%%sr1,%2),%%r20\n"
"2: ldw 8(%%sr1,%2),%%r21\n"
" vshd %1, %R1, %%r1\n"
" vshd %%r0, %1, %1\n"
" vshd %R1, %%r0, %R1\n"
" and %%r20, %%r19, %%r20\n"
" andcm %%r21, %%r19, %%r21\n"
" or %1, %%r20, %1\n"
" or %R1, %%r21, %R1\n"
"3: stw %1,0(%%sr1,%2)\n"
"4: stw %%r1,4(%%sr1,%2)\n"
"5: stw %R1,8(%%sr1,%2)\n"
"6: \n"
ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 6b)
ASM_EXCEPTIONTABLE_ENTRY_EFAULT(2b, 6b)
ASM_EXCEPTIONTABLE_ENTRY_EFAULT(3b, 6b)
ASM_EXCEPTIONTABLE_ENTRY_EFAULT(4b, 6b)
ASM_EXCEPTIONTABLE_ENTRY_EFAULT(5b, 6b)
: "+r" (ret)
: "r" (val), "r" (regs->ior), "r" (regs->isr)
: "r19", "r20", "r21", "r1" );
}
#endif
return ret;
}
void handle_unaligned(struct pt_regs *regs)
{
static DEFINE_RATELIMIT_STATE(ratelimit, 5 * HZ, 5);
unsigned long newbase = R1(regs->iir)?regs->gr[R1(regs->iir)]:0;
int modify = 0;
int ret = ERR_NOTHANDLED;
__inc_irq_stat(irq_unaligned_count);
/* log a message with pacing */
if (user_mode(regs)) {
if (current->thread.flags & PARISC_UAC_SIGBUS) {
goto force_sigbus;
}
if (!(current->thread.flags & PARISC_UAC_NOPRINT) &&
__ratelimit(&ratelimit)) {
printk(KERN_WARNING "%s(%d): unaligned access to " RFMT
" at ip " RFMT " (iir " RFMT ")\n",
current->comm, task_pid_nr(current), regs->ior,
regs->iaoq[0], regs->iir);
#ifdef DEBUG_UNALIGNED
show_regs(regs);
#endif
}
if (!unaligned_enabled)
goto force_sigbus;
}
/* handle modification - OK, it's ugly, see the instruction manual */
switch (MAJOR_OP(regs->iir))
{
case 0x03:
case 0x09:
case 0x0b:
if (regs->iir&0x20)
{
modify = 1;
if (regs->iir&0x1000) /* short loads */
if (regs->iir&0x200)
newbase += IM5_3(regs->iir);
else
newbase += IM5_2(regs->iir);
else if (regs->iir&0x2000) /* scaled indexed */
{
int shift=0;
switch (regs->iir & OPCODE1_MASK)
{
case OPCODE_LDH_I:
shift= 1; break;
case OPCODE_LDW_I:
shift= 2; break;
case OPCODE_LDD_I:
case OPCODE_LDDA_I:
shift= 3; break;
}
newbase += (R2(regs->iir)?regs->gr[R2(regs->iir)]:0)<<shift;
} else /* simple indexed */
newbase += (R2(regs->iir)?regs->gr[R2(regs->iir)]:0);
}
break;
case 0x13:
case 0x1b:
modify = 1;
newbase += IM14(regs->iir);
break;
case 0x14:
case 0x1c:
if (regs->iir&8)
{
modify = 1;
newbase += IM14(regs->iir&~0xe);
}
break;
case 0x16:
case 0x1e:
modify = 1;
newbase += IM14(regs->iir&6);
break;
case 0x17:
case 0x1f:
if (regs->iir&4)
{
modify = 1;
newbase += IM14(regs->iir&~4);
}
break;
}
/* TODO: make this cleaner... */
switch (regs->iir & OPCODE1_MASK)
{
case OPCODE_LDH_I:
case OPCODE_LDH_S:
ret = emulate_ldh(regs, R3(regs->iir));
break;
case OPCODE_LDW_I:
case OPCODE_LDWA_I:
case OPCODE_LDW_S:
case OPCODE_LDWA_S:
ret = emulate_ldw(regs, R3(regs->iir), 0);
break;
case OPCODE_STH:
ret = emulate_sth(regs, R2(regs->iir));
break;
case OPCODE_STW:
case OPCODE_STWA:
ret = emulate_stw(regs, R2(regs->iir), 0);
break;
#ifdef CONFIG_64BIT
case OPCODE_LDD_I:
case OPCODE_LDDA_I:
case OPCODE_LDD_S:
case OPCODE_LDDA_S:
ret = emulate_ldd(regs, R3(regs->iir), 0);
break;
case OPCODE_STD:
case OPCODE_STDA:
ret = emulate_std(regs, R2(regs->iir), 0);
break;
#endif
case OPCODE_FLDWX:
case OPCODE_FLDWS:
case OPCODE_FLDWXR:
case OPCODE_FLDWSR:
ret = emulate_ldw(regs, FR3(regs->iir), 1);
break;
case OPCODE_FLDDX:
case OPCODE_FLDDS:
ret = emulate_ldd(regs, R3(regs->iir), 1);
break;
case OPCODE_FSTWX:
case OPCODE_FSTWS:
case OPCODE_FSTWXR:
case OPCODE_FSTWSR:
ret = emulate_stw(regs, FR3(regs->iir), 1);
break;
case OPCODE_FSTDX:
case OPCODE_FSTDS:
ret = emulate_std(regs, R3(regs->iir), 1);
break;
case OPCODE_LDCD_I:
case OPCODE_LDCW_I:
case OPCODE_LDCD_S:
case OPCODE_LDCW_S:
ret = ERR_NOTHANDLED; /* "undefined", but lets kill them. */
break;
}
switch (regs->iir & OPCODE2_MASK)
{
case OPCODE_FLDD_L:
ret = emulate_ldd(regs,R2(regs->iir),1);
break;
case OPCODE_FSTD_L:
ret = emulate_std(regs, R2(regs->iir),1);
break;
#ifdef CONFIG_64BIT
case OPCODE_LDD_L:
ret = emulate_ldd(regs, R2(regs->iir),0);
break;
case OPCODE_STD_L:
ret = emulate_std(regs, R2(regs->iir),0);
break;
#endif
}
switch (regs->iir & OPCODE3_MASK)
{
case OPCODE_FLDW_L:
ret = emulate_ldw(regs, R2(regs->iir), 1);
break;
case OPCODE_LDW_M:
ret = emulate_ldw(regs, R2(regs->iir), 0);
break;
case OPCODE_FSTW_L:
ret = emulate_stw(regs, R2(regs->iir),1);
break;
case OPCODE_STW_M:
ret = emulate_stw(regs, R2(regs->iir),0);
break;
}
switch (regs->iir & OPCODE4_MASK)
{
case OPCODE_LDH_L:
ret = emulate_ldh(regs, R2(regs->iir));
break;
case OPCODE_LDW_L:
case OPCODE_LDWM:
ret = emulate_ldw(regs, R2(regs->iir),0);
break;
case OPCODE_STH_L:
ret = emulate_sth(regs, R2(regs->iir));
break;
case OPCODE_STW_L:
case OPCODE_STWM:
ret = emulate_stw(regs, R2(regs->iir),0);
break;
}
if (ret == 0 && modify && R1(regs->iir))
regs->gr[R1(regs->iir)] = newbase;
if (ret == ERR_NOTHANDLED)
printk(KERN_CRIT "Not-handled unaligned insn 0x%08lx\n", regs->iir);
DPRINTF("ret = %d\n", ret);
if (ret)
{
/*
* The unaligned handler failed.
* If we were called by __get_user() or __put_user() jump
* to it's exception fixup handler instead of crashing.
*/
if (!user_mode(regs) && fixup_exception(regs))
return;
printk(KERN_CRIT "Unaligned handler failed, ret = %d\n", ret);
die_if_kernel("Unaligned data reference", regs, 28);
if (ret == -EFAULT)
{
force_sig_fault(SIGSEGV, SEGV_MAPERR,
(void __user *)regs->ior);
}
else
{
force_sigbus:
/* couldn't handle it ... */
force_sig_fault(SIGBUS, BUS_ADRALN,
(void __user *)regs->ior);
}
return;
}
/* else we handled it, let life go on. */
regs->gr[0]|=PSW_N;
}
/*
* NB: check_unaligned() is only used for PCXS processors right
* now, so we only check for PA1.1 encodings at this point.
*/
int
check_unaligned(struct pt_regs *regs)
{
unsigned long align_mask;
/* Get alignment mask */
align_mask = 0UL;
switch (regs->iir & OPCODE1_MASK) {
case OPCODE_LDH_I:
case OPCODE_LDH_S:
case OPCODE_STH:
align_mask = 1UL;
break;
case OPCODE_LDW_I:
case OPCODE_LDWA_I:
case OPCODE_LDW_S:
case OPCODE_LDWA_S:
case OPCODE_STW:
case OPCODE_STWA:
align_mask = 3UL;
break;
default:
switch (regs->iir & OPCODE4_MASK) {
case OPCODE_LDH_L:
case OPCODE_STH_L:
align_mask = 1UL;
break;
case OPCODE_LDW_L:
case OPCODE_LDWM:
case OPCODE_STW_L:
case OPCODE_STWM:
align_mask = 3UL;
break;
}
break;
}
return (int)(regs->ior & align_mask);
}