327 lines
5.3 KiB
C
327 lines
5.3 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/uaccess.h>
|
|
#include <linux/ptrace.h>
|
|
|
|
static int align_enable = 1;
|
|
static int align_count;
|
|
|
|
static inline uint32_t get_ptreg(struct pt_regs *regs, uint32_t rx)
|
|
{
|
|
return rx == 15 ? regs->lr : *((uint32_t *)&(regs->a0) - 2 + rx);
|
|
}
|
|
|
|
static inline void put_ptreg(struct pt_regs *regs, uint32_t rx, uint32_t val)
|
|
{
|
|
if (rx == 15)
|
|
regs->lr = val;
|
|
else
|
|
*((uint32_t *)&(regs->a0) - 2 + rx) = val;
|
|
}
|
|
|
|
/*
|
|
* Get byte-value from addr and set it to *valp.
|
|
*
|
|
* Success: return 0
|
|
* Failure: return 1
|
|
*/
|
|
static int ldb_asm(uint32_t addr, uint32_t *valp)
|
|
{
|
|
uint32_t val;
|
|
int err;
|
|
|
|
if (!access_ok((void *)addr, 1))
|
|
return 1;
|
|
|
|
asm volatile (
|
|
"movi %0, 0\n"
|
|
"1:\n"
|
|
"ldb %1, (%2)\n"
|
|
"br 3f\n"
|
|
"2:\n"
|
|
"movi %0, 1\n"
|
|
"br 3f\n"
|
|
".section __ex_table,\"a\"\n"
|
|
".align 2\n"
|
|
".long 1b, 2b\n"
|
|
".previous\n"
|
|
"3:\n"
|
|
: "=&r"(err), "=r"(val)
|
|
: "r" (addr)
|
|
);
|
|
|
|
*valp = val;
|
|
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* Put byte-value to addr.
|
|
*
|
|
* Success: return 0
|
|
* Failure: return 1
|
|
*/
|
|
static int stb_asm(uint32_t addr, uint32_t val)
|
|
{
|
|
int err;
|
|
|
|
if (!access_ok((void *)addr, 1))
|
|
return 1;
|
|
|
|
asm volatile (
|
|
"movi %0, 0\n"
|
|
"1:\n"
|
|
"stb %1, (%2)\n"
|
|
"br 3f\n"
|
|
"2:\n"
|
|
"movi %0, 1\n"
|
|
"br 3f\n"
|
|
".section __ex_table,\"a\"\n"
|
|
".align 2\n"
|
|
".long 1b, 2b\n"
|
|
".previous\n"
|
|
"3:\n"
|
|
: "=&r"(err)
|
|
: "r"(val), "r" (addr)
|
|
);
|
|
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* Get half-word from [rx + imm]
|
|
*
|
|
* Success: return 0
|
|
* Failure: return 1
|
|
*/
|
|
static int ldh_c(struct pt_regs *regs, uint32_t rz, uint32_t addr)
|
|
{
|
|
uint32_t byte0, byte1;
|
|
|
|
if (ldb_asm(addr, &byte0))
|
|
return 1;
|
|
addr += 1;
|
|
if (ldb_asm(addr, &byte1))
|
|
return 1;
|
|
|
|
byte0 |= byte1 << 8;
|
|
put_ptreg(regs, rz, byte0);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Store half-word to [rx + imm]
|
|
*
|
|
* Success: return 0
|
|
* Failure: return 1
|
|
*/
|
|
static int sth_c(struct pt_regs *regs, uint32_t rz, uint32_t addr)
|
|
{
|
|
uint32_t byte0, byte1;
|
|
|
|
byte0 = byte1 = get_ptreg(regs, rz);
|
|
|
|
byte0 &= 0xff;
|
|
|
|
if (stb_asm(addr, byte0))
|
|
return 1;
|
|
|
|
addr += 1;
|
|
byte1 = (byte1 >> 8) & 0xff;
|
|
if (stb_asm(addr, byte1))
|
|
return 1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Get word from [rx + imm]
|
|
*
|
|
* Success: return 0
|
|
* Failure: return 1
|
|
*/
|
|
static int ldw_c(struct pt_regs *regs, uint32_t rz, uint32_t addr)
|
|
{
|
|
uint32_t byte0, byte1, byte2, byte3;
|
|
|
|
if (ldb_asm(addr, &byte0))
|
|
return 1;
|
|
|
|
addr += 1;
|
|
if (ldb_asm(addr, &byte1))
|
|
return 1;
|
|
|
|
addr += 1;
|
|
if (ldb_asm(addr, &byte2))
|
|
return 1;
|
|
|
|
addr += 1;
|
|
if (ldb_asm(addr, &byte3))
|
|
return 1;
|
|
|
|
byte0 |= byte1 << 8;
|
|
byte0 |= byte2 << 16;
|
|
byte0 |= byte3 << 24;
|
|
|
|
put_ptreg(regs, rz, byte0);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Store word to [rx + imm]
|
|
*
|
|
* Success: return 0
|
|
* Failure: return 1
|
|
*/
|
|
static int stw_c(struct pt_regs *regs, uint32_t rz, uint32_t addr)
|
|
{
|
|
uint32_t byte0, byte1, byte2, byte3;
|
|
|
|
byte0 = byte1 = byte2 = byte3 = get_ptreg(regs, rz);
|
|
|
|
byte0 &= 0xff;
|
|
|
|
if (stb_asm(addr, byte0))
|
|
return 1;
|
|
|
|
addr += 1;
|
|
byte1 = (byte1 >> 8) & 0xff;
|
|
if (stb_asm(addr, byte1))
|
|
return 1;
|
|
|
|
addr += 1;
|
|
byte2 = (byte2 >> 16) & 0xff;
|
|
if (stb_asm(addr, byte2))
|
|
return 1;
|
|
|
|
addr += 1;
|
|
byte3 = (byte3 >> 24) & 0xff;
|
|
if (stb_asm(addr, byte3))
|
|
return 1;
|
|
|
|
align_count++;
|
|
|
|
return 0;
|
|
}
|
|
|
|
extern int fixup_exception(struct pt_regs *regs);
|
|
|
|
#define OP_LDH 0xc000
|
|
#define OP_STH 0xd000
|
|
#define OP_LDW 0x8000
|
|
#define OP_STW 0x9000
|
|
|
|
void csky_alignment(struct pt_regs *regs)
|
|
{
|
|
int ret;
|
|
uint16_t tmp;
|
|
uint32_t opcode = 0;
|
|
uint32_t rx = 0;
|
|
uint32_t rz = 0;
|
|
uint32_t imm = 0;
|
|
uint32_t addr = 0;
|
|
|
|
if (!user_mode(regs))
|
|
goto bad_area;
|
|
|
|
ret = get_user(tmp, (uint16_t *)instruction_pointer(regs));
|
|
if (ret) {
|
|
pr_err("%s get_user failed.\n", __func__);
|
|
goto bad_area;
|
|
}
|
|
|
|
opcode = (uint32_t)tmp;
|
|
|
|
rx = opcode & 0xf;
|
|
imm = (opcode >> 4) & 0xf;
|
|
rz = (opcode >> 8) & 0xf;
|
|
opcode &= 0xf000;
|
|
|
|
if (rx == 0 || rx == 1 || rz == 0 || rz == 1)
|
|
goto bad_area;
|
|
|
|
switch (opcode) {
|
|
case OP_LDH:
|
|
addr = get_ptreg(regs, rx) + (imm << 1);
|
|
ret = ldh_c(regs, rz, addr);
|
|
break;
|
|
case OP_LDW:
|
|
addr = get_ptreg(regs, rx) + (imm << 2);
|
|
ret = ldw_c(regs, rz, addr);
|
|
break;
|
|
case OP_STH:
|
|
addr = get_ptreg(regs, rx) + (imm << 1);
|
|
ret = sth_c(regs, rz, addr);
|
|
break;
|
|
case OP_STW:
|
|
addr = get_ptreg(regs, rx) + (imm << 2);
|
|
ret = stw_c(regs, rz, addr);
|
|
break;
|
|
}
|
|
|
|
if (ret)
|
|
goto bad_area;
|
|
|
|
regs->pc += 2;
|
|
|
|
return;
|
|
|
|
bad_area:
|
|
if (!user_mode(regs)) {
|
|
if (fixup_exception(regs))
|
|
return;
|
|
|
|
bust_spinlocks(1);
|
|
pr_alert("%s opcode: %x, rz: %d, rx: %d, imm: %d, addr: %x.\n",
|
|
__func__, opcode, rz, rx, imm, addr);
|
|
show_regs(regs);
|
|
bust_spinlocks(0);
|
|
do_exit(SIGKILL);
|
|
}
|
|
|
|
force_sig_fault(SIGBUS, BUS_ADRALN, (void __user *)addr, current);
|
|
}
|
|
|
|
static struct ctl_table alignment_tbl[4] = {
|
|
{
|
|
.procname = "enable",
|
|
.data = &align_enable,
|
|
.maxlen = sizeof(align_enable),
|
|
.mode = 0666,
|
|
.proc_handler = &proc_dointvec
|
|
},
|
|
{
|
|
.procname = "count",
|
|
.data = &align_count,
|
|
.maxlen = sizeof(align_count),
|
|
.mode = 0666,
|
|
.proc_handler = &proc_dointvec
|
|
},
|
|
{}
|
|
};
|
|
|
|
static struct ctl_table sysctl_table[2] = {
|
|
{
|
|
.procname = "csky_alignment",
|
|
.mode = 0555,
|
|
.child = alignment_tbl},
|
|
{}
|
|
};
|
|
|
|
static struct ctl_path sysctl_path[2] = {
|
|
{.procname = "csky"},
|
|
{}
|
|
};
|
|
|
|
static int __init csky_alignment_init(void)
|
|
{
|
|
register_sysctl_paths(sysctl_path, sysctl_table);
|
|
return 0;
|
|
}
|
|
|
|
arch_initcall(csky_alignment_init);
|