forked from Minki/linux
266 lines
6.3 KiB
C
266 lines
6.3 KiB
C
/*
|
|
* Copyright (C) 2011-2012 Synopsys (www.synopsys.com)
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
* published by the Free Software Foundation.
|
|
*
|
|
* vineetg : May 2011
|
|
* -Adapted (from .26 to .35)
|
|
* -original contribution by Tim.yao@amlogic.com
|
|
*
|
|
*/
|
|
|
|
#include <linux/types.h>
|
|
#include <linux/perf_event.h>
|
|
#include <linux/ptrace.h>
|
|
#include <linux/uaccess.h>
|
|
#include <asm/disasm.h>
|
|
|
|
#ifdef CONFIG_CPU_BIG_ENDIAN
|
|
#define BE 1
|
|
#define FIRST_BYTE_16 "swap %1, %1\n swape %1, %1\n"
|
|
#define FIRST_BYTE_32 "swape %1, %1\n"
|
|
#else
|
|
#define BE 0
|
|
#define FIRST_BYTE_16
|
|
#define FIRST_BYTE_32
|
|
#endif
|
|
|
|
#define __get8_unaligned_check(val, addr, err) \
|
|
__asm__( \
|
|
"1: ldb.ab %1, [%2, 1]\n" \
|
|
"2:\n" \
|
|
" .section .fixup,\"ax\"\n" \
|
|
" .align 4\n" \
|
|
"3: mov %0, 1\n" \
|
|
" b 2b\n" \
|
|
" .previous\n" \
|
|
" .section __ex_table,\"a\"\n" \
|
|
" .align 4\n" \
|
|
" .long 1b, 3b\n" \
|
|
" .previous\n" \
|
|
: "=r" (err), "=&r" (val), "=r" (addr) \
|
|
: "0" (err), "2" (addr))
|
|
|
|
#define get16_unaligned_check(val, addr) \
|
|
do { \
|
|
unsigned int err = 0, v, a = addr; \
|
|
__get8_unaligned_check(v, a, err); \
|
|
val = v << ((BE) ? 8 : 0); \
|
|
__get8_unaligned_check(v, a, err); \
|
|
val |= v << ((BE) ? 0 : 8); \
|
|
if (err) \
|
|
goto fault; \
|
|
} while (0)
|
|
|
|
#define get32_unaligned_check(val, addr) \
|
|
do { \
|
|
unsigned int err = 0, v, a = addr; \
|
|
__get8_unaligned_check(v, a, err); \
|
|
val = v << ((BE) ? 24 : 0); \
|
|
__get8_unaligned_check(v, a, err); \
|
|
val |= v << ((BE) ? 16 : 8); \
|
|
__get8_unaligned_check(v, a, err); \
|
|
val |= v << ((BE) ? 8 : 16); \
|
|
__get8_unaligned_check(v, a, err); \
|
|
val |= v << ((BE) ? 0 : 24); \
|
|
if (err) \
|
|
goto fault; \
|
|
} while (0)
|
|
|
|
#define put16_unaligned_check(val, addr) \
|
|
do { \
|
|
unsigned int err = 0, v = val, a = addr;\
|
|
\
|
|
__asm__( \
|
|
FIRST_BYTE_16 \
|
|
"1: stb.ab %1, [%2, 1]\n" \
|
|
" lsr %1, %1, 8\n" \
|
|
"2: stb %1, [%2]\n" \
|
|
"3:\n" \
|
|
" .section .fixup,\"ax\"\n" \
|
|
" .align 4\n" \
|
|
"4: mov %0, 1\n" \
|
|
" b 3b\n" \
|
|
" .previous\n" \
|
|
" .section __ex_table,\"a\"\n" \
|
|
" .align 4\n" \
|
|
" .long 1b, 4b\n" \
|
|
" .long 2b, 4b\n" \
|
|
" .previous\n" \
|
|
: "=r" (err), "=&r" (v), "=&r" (a) \
|
|
: "0" (err), "1" (v), "2" (a)); \
|
|
\
|
|
if (err) \
|
|
goto fault; \
|
|
} while (0)
|
|
|
|
#define put32_unaligned_check(val, addr) \
|
|
do { \
|
|
unsigned int err = 0, v = val, a = addr;\
|
|
\
|
|
__asm__( \
|
|
FIRST_BYTE_32 \
|
|
"1: stb.ab %1, [%2, 1]\n" \
|
|
" lsr %1, %1, 8\n" \
|
|
"2: stb.ab %1, [%2, 1]\n" \
|
|
" lsr %1, %1, 8\n" \
|
|
"3: stb.ab %1, [%2, 1]\n" \
|
|
" lsr %1, %1, 8\n" \
|
|
"4: stb %1, [%2]\n" \
|
|
"5:\n" \
|
|
" .section .fixup,\"ax\"\n" \
|
|
" .align 4\n" \
|
|
"6: mov %0, 1\n" \
|
|
" b 5b\n" \
|
|
" .previous\n" \
|
|
" .section __ex_table,\"a\"\n" \
|
|
" .align 4\n" \
|
|
" .long 1b, 6b\n" \
|
|
" .long 2b, 6b\n" \
|
|
" .long 3b, 6b\n" \
|
|
" .long 4b, 6b\n" \
|
|
" .previous\n" \
|
|
: "=r" (err), "=&r" (v), "=&r" (a) \
|
|
: "0" (err), "1" (v), "2" (a)); \
|
|
\
|
|
if (err) \
|
|
goto fault; \
|
|
} while (0)
|
|
|
|
/* sysctl hooks */
|
|
int unaligned_enabled __read_mostly = 1; /* Enabled by default */
|
|
int no_unaligned_warning __read_mostly = 1; /* Only 1 warning by default */
|
|
|
|
static void fixup_load(struct disasm_state *state, struct pt_regs *regs,
|
|
struct callee_regs *cregs)
|
|
{
|
|
int val;
|
|
|
|
/* register write back */
|
|
if ((state->aa == 1) || (state->aa == 2)) {
|
|
set_reg(state->wb_reg, state->src1 + state->src2, regs, cregs);
|
|
|
|
if (state->aa == 2)
|
|
state->src2 = 0;
|
|
}
|
|
|
|
if (state->zz == 0) {
|
|
get32_unaligned_check(val, state->src1 + state->src2);
|
|
} else {
|
|
get16_unaligned_check(val, state->src1 + state->src2);
|
|
|
|
if (state->x)
|
|
val = (val << 16) >> 16;
|
|
}
|
|
|
|
if (state->pref == 0)
|
|
set_reg(state->dest, val, regs, cregs);
|
|
|
|
return;
|
|
|
|
fault: state->fault = 1;
|
|
}
|
|
|
|
static void fixup_store(struct disasm_state *state, struct pt_regs *regs,
|
|
struct callee_regs *cregs)
|
|
{
|
|
/* register write back */
|
|
if ((state->aa == 1) || (state->aa == 2)) {
|
|
set_reg(state->wb_reg, state->src2 + state->src3, regs, cregs);
|
|
|
|
if (state->aa == 3)
|
|
state->src3 = 0;
|
|
} else if (state->aa == 3) {
|
|
if (state->zz == 2) {
|
|
set_reg(state->wb_reg, state->src2 + (state->src3 << 1),
|
|
regs, cregs);
|
|
} else if (!state->zz) {
|
|
set_reg(state->wb_reg, state->src2 + (state->src3 << 2),
|
|
regs, cregs);
|
|
} else {
|
|
goto fault;
|
|
}
|
|
}
|
|
|
|
/* write fix-up */
|
|
if (!state->zz)
|
|
put32_unaligned_check(state->src1, state->src2 + state->src3);
|
|
else
|
|
put16_unaligned_check(state->src1, state->src2 + state->src3);
|
|
|
|
return;
|
|
|
|
fault: state->fault = 1;
|
|
}
|
|
|
|
/*
|
|
* Handle an unaligned access
|
|
* Returns 0 if successfully handled, 1 if some error happened
|
|
*/
|
|
int misaligned_fixup(unsigned long address, struct pt_regs *regs,
|
|
struct callee_regs *cregs)
|
|
{
|
|
struct disasm_state state;
|
|
char buf[TASK_COMM_LEN];
|
|
|
|
/* handle user mode only and only if enabled by sysadmin */
|
|
if (!user_mode(regs) || !unaligned_enabled)
|
|
return 1;
|
|
|
|
if (no_unaligned_warning) {
|
|
pr_warn_once("%s(%d) made unaligned access which was emulated"
|
|
" by kernel assist\n. This can degrade application"
|
|
" performance significantly\n. To enable further"
|
|
" logging of such instances, please \n"
|
|
" echo 0 > /proc/sys/kernel/ignore-unaligned-usertrap\n",
|
|
get_task_comm(buf, current), task_pid_nr(current));
|
|
} else {
|
|
/* Add rate limiting if it gets down to it */
|
|
pr_warn("%s(%d): unaligned access to/from 0x%lx by PC: 0x%lx\n",
|
|
get_task_comm(buf, current), task_pid_nr(current),
|
|
address, regs->ret);
|
|
|
|
}
|
|
|
|
disasm_instr(regs->ret, &state, 1, regs, cregs);
|
|
|
|
if (state.fault)
|
|
goto fault;
|
|
|
|
/* ldb/stb should not have unaligned exception */
|
|
if ((state.zz == 1) || (state.di))
|
|
goto fault;
|
|
|
|
if (!state.write)
|
|
fixup_load(&state, regs, cregs);
|
|
else
|
|
fixup_store(&state, regs, cregs);
|
|
|
|
if (state.fault)
|
|
goto fault;
|
|
|
|
if (delay_mode(regs)) {
|
|
regs->ret = regs->bta;
|
|
regs->status32 &= ~STATUS_DE_MASK;
|
|
} else {
|
|
regs->ret += state.instr_len;
|
|
|
|
/* handle zero-overhead-loop */
|
|
if ((regs->ret == regs->lp_end) && (regs->lp_count)) {
|
|
regs->ret = regs->lp_start;
|
|
regs->lp_count--;
|
|
}
|
|
}
|
|
|
|
perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS, 1, regs, address);
|
|
return 0;
|
|
|
|
fault:
|
|
pr_err("Alignment trap: fault in fix-up %08lx at [<%08lx>]\n",
|
|
state.words[0], address);
|
|
|
|
return 1;
|
|
}
|