Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752353AbaDRMmO (ORCPT ); Fri, 18 Apr 2014 08:42:14 -0400 Received: from mail-bn1on0131.outbound.protection.outlook.com ([157.56.110.131]:33108 "EHLO na01-bn1-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752165AbaDRMmJ (ORCPT ); Fri, 18 Apr 2014 08:42:09 -0400 From: Ley Foon Tan To: , , CC: Ley Foon Tan , , Subject: [PATCH 04/28] nios2: Exception handling Date: Fri, 18 Apr 2014 20:26:50 +0800 Message-ID: <1397824031-4892-4-git-send-email-lftan@altera.com> X-Mailer: git-send-email 1.8.3.2 In-Reply-To: <1397824031-4892-1-git-send-email-lftan@altera.com> References: <1397824031-4892-1-git-send-email-lftan@altera.com> MIME-Version: 1.0 Content-Type: text/plain X-EOPAttributedMessage: 0 X-Forefront-Antispam-Report: CIP:66.35.236.232;CTRY:US;IPV:NLI;EFV:NLI;SFV:NSPM;SFS:(10019001)(6009001)(458001)(22564002)(189002)(199002)(87936001)(31966008)(77982001)(16796002)(74662001)(84676001)(77156001)(89996001)(87286001)(99396002)(85852003)(83072002)(76482001)(2009001)(74502001)(47776003)(20776003)(42186004)(2201001)(19580405001)(83322001)(92726001)(92566001)(88136002)(19580395003)(6806004)(44976005)(36756003)(50986999)(50466002)(80022001)(93916002)(575784001)(46102001)(86362001)(97736001)(4396001)(50226001)(48376002)(81342001)(76176999)(81542001)(62966002)(80976001);DIR:OUT;SFP:1102;SCL:1;SRVR:BL2FFO11HUB036;H:SJ-ITEXEDGE02.altera.priv.altera.com;FPR:EEEDD35D.48FEDFE1.7CD99176.AC75372.20CFF;MLV:sfv;PTR:InfoDomainNonexistent;MX:1;A:1;LANG:en; X-OriginatorOrg: altera.onmicrosoft.com X-Forefront-PRVS: 018577E36E Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch contains the exception entry code (kernel/entry.S) and misaligned exception. Signed-off-by: Ley Foon Tan --- arch/nios2/kernel/entry.S | 551 +++++++++++++++++++++++++++++++++++++++++ arch/nios2/kernel/misaligned.c | 319 ++++++++++++++++++++++++ 2 files changed, 870 insertions(+) create mode 100644 arch/nios2/kernel/entry.S create mode 100644 arch/nios2/kernel/misaligned.c diff --git a/arch/nios2/kernel/entry.S b/arch/nios2/kernel/entry.S new file mode 100644 index 0000000..cda0854d1d29450325fa90ab62ced2c215035f3c --- /dev/null +++ b/arch/nios2/kernel/entry.S @@ -0,0 +1,551 @@ +/* + * linux/arch/nios2/kernel/entry.S + * + * Copyright (C) 2013 Altera Corporation + * Copyright (C) 2009, Wind River Systems Inc + * + * Implemented by fredrik.markstrom@gmail.com and ivarholmqvist@gmail.com + * + * Based on: + * + * linux/arch/nios2/kernel/entry.S + * + * Copyright (C) 1999-2002, Greg Ungerer (gerg@snapgear.com) + * Copyright (C) 1998 D. Jeff Dionne , + * Kenneth Albanowski , + * Copyright (C) 2000 Lineo Inc. (www.lineo.com) + * Copyright (C) 2004 Microtronix Datacom Ltd. + * + * Based on: + * + * linux/arch/m68knommu/kernel/entry.S + * + * Copyright (C) 1991, 1992 Linus Torvalds + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Linux/m68k support by Hamish Macdonald + * + * 68060 fixes by Jesper Skov + * ColdFire support by Greg Ungerer (gerg@snapgear.com) + * 5307 fixes by David W. Miller + * linux 2.4 support David McCullough + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +.macro GET_THREAD_INFO reg +.if THREAD_SIZE & 0xffff0000 + andhi \reg, sp, %hi(~(THREAD_SIZE-1)) +.else + addi \reg, r0, %lo(~(THREAD_SIZE-1)) + and \reg, \reg, sp +.endif +.endm + +.macro kuser_cmpxchg_check + /* + * Make sure our user space atomic helper is restarted if it was + * interrupted in a critical region. + * ea-4 = address of interrupted insn (ea must be preserved). + * sp = saved regs. + * cmpxchg_ldw = first critical insn, cmpxchg_stw = last critical insn. + * If ea <= cmpxchg_stw and ea > cmpxchg_ldw then saved EA is set to + * cmpxchg_ldw + 4. + */ + /* et = cmpxchg_stw + 4 */ + movui et, (KUSER_BASE + 4 + (cmpxchg_stw - __kuser_helper_start)) + bgtu ea, et, 1f + + subi et, et, (cmpxchg_stw - cmpxchg_ldw) /* et = cmpxchg_ldw + 4 */ + bltu ea, et, 1f + stw et, PT_EA(sp) /* fix up EA */ + mov ea, et +1: +.endm + +.section .rodata +.align 4 +exception_table: + .word unhandled_exception /* 0 - Reset */ + .word unhandled_exception /* 1 - Processor-only Reset */ + .word external_interrupt /* 2 - Interrupt */ + .word handle_trap /* 3 - Trap Instruction */ + + .word instruction_trap /* 4 - Unimplemented instruction */ + .word handle_illegal /* 5 - Illegal instruction */ + .word handle_unaligned /* 6 - Misaligned data access */ + .word handle_unaligned /* 7 - Misaligned destination address */ + + .word handle_diverror /* 8 - Division error */ + .word protection_exception_ba /* 9 - Supervisor-only instr. address */ + .word protection_exception_instr /* 10 - Supervisor only instruction */ + .word protection_exception_ba /* 11 - Supervisor only data address */ + + .word unhandled_exception /* 12 - Double TLB miss (data) */ + .word protection_exception_pte /* 13 - TLB permission violation (x) */ + .word protection_exception_pte /* 14 - TLB permission violation (r) */ + .word protection_exception_pte /* 15 - TLB permission violation (w) */ + + .word unhandled_exception /* 16 - MPU region violation */ + +trap_table: + .word handle_system_call /* 0 */ + .word instruction_trap /* 1 */ + .word instruction_trap /* 2 */ + .word instruction_trap /* 3 */ + .word instruction_trap /* 4 */ + .word instruction_trap /* 5 */ + .word instruction_trap /* 6 */ + .word instruction_trap /* 7 */ + .word instruction_trap /* 8 */ + .word instruction_trap /* 9 */ + .word instruction_trap /* 10 */ + .word instruction_trap /* 11 */ + .word instruction_trap /* 12 */ + .word instruction_trap /* 13 */ + .word instruction_trap /* 14 */ + .word instruction_trap /* 15 */ + .word instruction_trap /* 16 */ + .word instruction_trap /* 17 */ + .word instruction_trap /* 18 */ + .word instruction_trap /* 19 */ + .word instruction_trap /* 20 */ + .word instruction_trap /* 21 */ + .word instruction_trap /* 22 */ + .word instruction_trap /* 23 */ + .word instruction_trap /* 24 */ + .word instruction_trap /* 25 */ + .word instruction_trap /* 26 */ + .word instruction_trap /* 27 */ + .word instruction_trap /* 28 */ + .word instruction_trap /* 29 */ + .word instruction_trap /* 30 */ + .word handle_breakpoint /* 31 */ + +.text +.set noat +.set nobreak + +ENTRY(inthandler) + SAVE_ALL + + kuser_cmpxchg_check + + /* Clear EH bit before we get a new excpetion in the kernel + * and after we have saved it to the exception frame. This is done + * wheter it's trap, tlb-miss or interrupt. If we don't do this + * estatus is not updated the next exception. + */ + rdctl r24, status + movi r9, %lo(~STATUS_EH) + and r24, r24, r9 + wrctl status, r24 + + /* Read cause and vector and branch to the associated handler */ + mov r4, sp + rdctl r5, exception + movia r9, exception_table + add r24, r9, r5 + ldw r24, 0(r24) + jmp r24 + + +/*********************************************************************** + * Handle traps + *********************************************************************** + */ +ENTRY(handle_trap) + ldw r24, -4(ea) /* instruction that caused the exception */ + srli r24, r24, 4 + andi r24, r24, 0x7c + movia r9,trap_table + add r24, r24, r9 + ldw r24, 0(r24) + jmp r24 + + +/*********************************************************************** + * Handle system calls + *********************************************************************** + */ +ENTRY(handle_system_call) + /* Enable interrupts */ + rdctl r10, status + ori r10, r10, STATUS_PIE + wrctl status, r10 + + /* Reload registers destroyed by common code. */ + ldw r4, PT_R4(sp) + ldw r5, PT_R5(sp) + + /* Check that the requested system call is within limits */ + movui r1, __NR_syscalls + bgeu r2, r1, ret_invsyscall + slli r1, r2, 2 + movhi r11, %hiadj(sys_call_table) + add r1, r1, r11 + ldw r1, %lo(sys_call_table)(r1) + beq r1, r0, ret_invsyscall + + /* Get thread info pointer */ + movi r11, %lo(0xfffff000) + and r11, sp, r11 + ldw r11, TI_FLAGS(r11) + + /* If someone is ptrace:ing us, take the long way. */ + BTBNZ r11, r11, TIF_SYSCALL_TRACE, traced_system_call + + /* Execute the system call */ + callr r1 + + /* If the syscall returns a negative result: + * Set r7 to 1 to indicate error, + * Negate r2 to get a positive error code + * If the syscall returns zero or a positive value: + * Set r7 to 0. + * The sigreturn system calls will skip the code below by + * adding to register ra. To avoid destroying registers + */ +translate_rc_and_ret: + movi r1, 0 + bge r2, zero, 3f + sub r2, zero, r2 + movi r1, 1 +3: + stw r2, PT_R2(sp) + stw r1, PT_R7(sp) +end_translate_rc_and_ret: + +ret_from_exception: + ldw r1, PT_ESTATUS(sp) + /* if so, skip resched, signals */ + TSTBNZ r1, r1, ESTATUS_EU, Luser_return + +restore_all: + rdctl r10, status /* disable intrs */ + andi r10, r10, %lo(~STATUS_PIE) + wrctl status, r10 + RESTORE_ALL + eret + + /* If the syscall number was invalid return ENOSYS */ +ret_invsyscall: + movi r2, -ENOSYS + br translate_rc_and_ret + + /* This implements the same as above, except it calls + * syscall_trace before and after the syscall in order + * for utilities like strace and gdb to work. + */ +traced_system_call: + SAVE_SWITCH_STACK + call syscall_trace + RESTORE_SWITCH_STACK + + /* Create system call register arguments. The 5th and 6th + arguments on stack are already in place at the beginning + of pt_regs. */ + ldw r2, PT_R2(sp) + ldw r4, PT_R4(sp) + ldw r5, PT_R5(sp) + ldw r6, PT_R6(sp) + ldw r7, PT_R7(sp) + + /* Fetch the syscall function, we don't need to check the boundaries + * since this is already done. + */ + slli r1, r2, 2 + movhi r11,%hiadj(sys_call_table) + add r1, r1, r11 + ldw r1, %lo(sys_call_table)(r1) + + callr r1 + + /* If the syscall returns a negative result: + * Set r7 to 1 to indicate error, + * Negate r2 to get a positive error code + * If the syscall returns zero or a positive value: + * Set r7 to 0. + * The sigreturn system calls will skip the code below by + * adding to register ra. To avoid destroying registers + */ +translate_rc_and_ret2: + movi r1, 0 + bge r2, zero, 4f + sub r2, zero, r2 + movi r1, 1 +4: + stw r2, PT_R2(sp) + stw r1, PT_R7(sp) +end_translate_rc_and_ret2: + SAVE_SWITCH_STACK + call syscall_trace + RESTORE_SWITCH_STACK + br ret_from_exception + +Luser_return: + GET_THREAD_INFO r11 /* get thread_info pointer */ + ldw r10, TI_FLAGS(r11) /* get thread_info->flags */ + ANDI32 r11, r10, _TIF_WORK_MASK + beq r11, r0, restore_all /* Nothing to do */ + BTBZ r1, r10, TIF_NEED_RESCHED, Lsignal_return + + /* Reschedule work */ + call schedule + br ret_from_exception + +Lsignal_return: + ANDI32 r1, r10, _TIF_SIGPENDING | _TIF_NOTIFY_RESUME + beq r1, r0, restore_all + mov r4, sp /* pt_regs */ + SAVE_SWITCH_STACK + mov r5, r0 /* oldset = 0 */ + movi r6, 1 /* in_syscall = 1 */ + call do_notify_resume + RESTORE_SWITCH_STACK + br restore_all + + + +/*********************************************************************** + * Handle external interrupts. + *********************************************************************** + */ +/* + * This is the generic interrupt handler (for all hardware interrupt + * sources). It figures out the vector number and calls the appropriate + * interrupt service routine directly. + */ +external_interrupt: + rdctl r12, ipending + rdctl r9, ienable + and r12, r12, r9 + /* skip if no interrupt is pending */ + beq r12, r0, ret_from_interrupt + + movi r24, -1 + stw r24, PT_ORIG_R2(sp) + + /* + * Process an external hardware interrupt. + */ + + addi ea, ea, -4 /* re-issue the interrupted instruction */ + stw ea, PT_EA(sp) +2: movi r4, %lo(-1) /* Start from bit position 0, + highest priority */ + /* This is the IRQ # for handler call */ +1: andi r10, r12, 1 /* Isolate bit we are interested in */ + srli r12, r12, 1 /* shift count is costly without hardware + multiplier */ + addi r4, r4, 1 + beq r10, r0, 1b + mov r5, sp /* Setup pt_regs pointer for handler call */ + call do_IRQ + rdctl r12, ipending /* check again if irq still pending */ + rdctl r9, ienable /* Isolate possible interrupts */ + and r12, r12, r9 + bne r12, r0, 2b + /* br ret_from_interrupt */ /* fall throught to ret_from_interrupt */ + +ENTRY(ret_from_interrupt) + ldw r1, PT_ESTATUS(sp) /* check if returning to kernel */ + TSTBNZ r1, r1, ESTATUS_EU, Luser_return + +#ifdef CONFIG_PREEMPT + GET_THREAD_INFO r1 + ldw r4, TI_PREEMPT_COUNT(r1) + bne r4, r0, restore_all + +need_resched: + ldw r4, TI_FLAGS(r1) /* ? Need resched set */ + BTBZ r10, r4, TIF_NEED_RESCHED, restore_all + ldw r4, PT_ESTATUS(sp) /* ? Interrupts off */ + andi r10, r4, ESTATUS_EPIE + beq r10, r0, restore_all + movia r4, PREEMPT_ACTIVE + stw r4, TI_PREEMPT_COUNT(r1) + rdctl r10, status /* enable intrs again */ + ori r10, r10 ,STATUS_PIE + wrctl status, r10 + PUSH r1 + call schedule + POP r1 + mov r4, r0 + stw r4, TI_PREEMPT_COUNT(r1) + rdctl r10, status /* disable intrs */ + andi r10, r10, %lo(~STATUS_PIE) + wrctl status, r10 + br need_resched +#else + br restore_all +#endif + +/*********************************************************************** + * A few syscall wrappers + *********************************************************************** + */ +/* + * int clone(unsigned long clone_flags, unsigned long newsp, + * int __user * parent_tidptr, int __user * child_tidptr, + * int tls_val) + */ +ENTRY(sys_clone) + SAVE_SWITCH_STACK + addi sp, sp, -4 + stw r7, 0(sp) /* Pass 5th arg thru stack */ + mov r7, r6 /* 4th arg is 3rd of clone() */ + mov r6, zero /* 3rd arg always 0 */ + call do_fork + addi sp, sp, 4 + RESTORE_SWITCH_STACK + ret + +ENTRY(sys_rt_sigreturn) + SAVE_SWITCH_STACK + mov r4, sp + call do_rt_sigreturn + RESTORE_SWITCH_STACK + addi ra, ra, (end_translate_rc_and_ret - translate_rc_and_ret) + ret + +/*********************************************************************** + * A few other wrappers and stubs + *********************************************************************** + */ +protection_exception_pte: + rdctl r6, pteaddr + slli r6, r6, 10 + call do_page_fault + br ret_from_exception + +protection_exception_ba: + rdctl r6, badaddr + call do_page_fault + br ret_from_exception + +protection_exception_instr: + call handle_supervisor_instr + br ret_from_exception + +handle_breakpoint: + call breakpoint_c + br ret_from_exception + +#ifdef CONFIG_ALIGNMENT_TRAP +handle_unaligned: + SAVE_SWITCH_STACK + call handle_unaligned_c + RESTORE_SWITCH_STACK + br ret_from_exception +#else +handle_unaligned: + call handle_unaligned_c + br ret_from_exception +#endif + +handle_illegal: + call handle_illegal_c + br ret_from_exception + +handle_diverror: + call handle_diverror_c + br ret_from_exception + +/* + * Beware - when entering resume, prev (the current task) is + * in r4, next (the new task) is in r5, don't change these + * registers. + */ +ENTRY(resume) + + rdctl r7, status /* save thread status reg */ + stw r7, TASK_THREAD + THREAD_KPSR(r4) + + andi r7, r7, %lo(~STATUS_PIE) /* disable interrupts */ + wrctl status, r7 + + SAVE_SWITCH_STACK + stw sp, TASK_THREAD + THREAD_KSP(r4)/* save kernel stack pointer */ + ldw sp, TASK_THREAD + THREAD_KSP(r5)/* restore new thread stack */ + movia r24, _current_thread /* save thread */ + GET_THREAD_INFO r1 + stw r1, 0(r24) + RESTORE_SWITCH_STACK + + ldw r7, TASK_THREAD + THREAD_KPSR(r5)/* restore thread status reg */ + wrctl status, r7 + ret + +ENTRY(ret_from_fork) + call schedule_tail + br ret_from_exception + +ENTRY(ret_from_kernel_thread) + call schedule_tail + mov r4,r17 /* arg */ + callr r16 /* function */ + br ret_from_exception + +/* + * Kernel user helpers. + * + * Each segment is 64-byte aligned and will be mapped to the . + * New segments (if ever needed) must be added after the existing ones. + * This mechanism should be used only for things that are really small and + * justified, and not be abused freely. + * + */ + + /* Filling pads with undefined instructions. */ +.macro kuser_pad sym size + .if ((. - \sym) & 3) + .rept (4 - (. - \sym) & 3) + .byte 0 + .endr + .endif + .rept ((\size - (. - \sym)) / 4) + .word 0xdeadbeef + .endr +.endm + + .align 6 + .globl __kuser_helper_start +__kuser_helper_start: + +__kuser_helper_version: /* @ 0x1000 */ + .word ((__kuser_helper_end - __kuser_helper_start) >> 6) + +__kuser_cmpxchg: /* @ 0x1004 */ + /* + * r4 pointer to exchange variable + * r5 old value + * r6 new value + */ +cmpxchg_ldw: + ldw r2, 0(r4) /* load current value */ + sub r2, r2, r5 /* compare with old value */ + bne r2, zero, cmpxchg_ret + + /* We had a match, store the new value */ +cmpxchg_stw: + stw r6, 0(r4) +cmpxchg_ret: + ret + + kuser_pad __kuser_cmpxchg, 64 + + .globl __kuser_helper_end +__kuser_helper_end: diff --git a/arch/nios2/kernel/misaligned.c b/arch/nios2/kernel/misaligned.c new file mode 100644 index 0000000..f8845ab72af03d946561c84c125fc8ab4f6fce1b --- /dev/null +++ b/arch/nios2/kernel/misaligned.c @@ -0,0 +1,319 @@ +/* + * linux/arch/nios2/kernel/misaligned.c + * + * basic emulation for mis-aligned accesses on the NIOS II cpu + * modeled after the version for arm in arm/alignment.c + * + * Brad Parker + * Copyright (C) 2010 Ambient Corporation + * Copyright (c) 2010 Altera Corporation, San Jose, California, USA. + * Copyright (c) 2010 Arrow Electronics, Inc. + * + * This file is subject to the terms and conditions of the GNU General + * Public License. See the file COPYING in the main directory of + * this archive for more details. + */ + +#include +#include +#include +#include +#include +#include +#include + +#include +#include + +/* instructions we emulate */ +#define INST_LDHU 0x0b +#define INST_STH 0x0d +#define INST_LDH 0x0f +#define INST_STW 0x15 +#define INST_LDW 0x17 + +static unsigned long ma_user, ma_kern, ma_skipped, ma_half, ma_word; + +static unsigned int ma_usermode; +#define UM_WARN 0x01 +#define UM_FIXUP 0x02 +#define UM_SIGNAL 0x04 +#define KM_WARN 0x08 + +/* see arch/nios2/include/asm/ptrace.h */ +static u8 sys_stack_frame_reg_offset[] = { + /* struct pt_regs */ + 8, 9, 10, 11, 12, 13, 14, 15, 1, 2, 3, 4, 5, 6, 7, 0, + /* struct switch_stack */ + 16, 17, 18, 19, 20, 21, 22, 23, 0, 0, 0, 0, 0, 0, 0, 0 +}; + +static int reg_offsets[32]; + +static inline u32 get_reg_val(struct pt_regs *fp, int reg) +{ + u8 *p = ((u8 *)fp) + reg_offsets[reg]; + return *(u32 *)p; +} + +static inline void put_reg_val(struct pt_regs *fp, int reg, u32 val) +{ + u8 *p = ((u8 *)fp) + reg_offsets[reg]; + *(u32 *)p = val; +} + +/* + * (mis)alignment handler + */ +asmlinkage void handle_unaligned_c(struct pt_regs *fp, int cause) +{ + u32 isn, addr, val; + int in_kernel; + u8 a, b, d0, d1, d2, d3; + u16 imm16; + unsigned int fault; + + /* back up one instruction */ + fp->ea -= 4; + + if (fixup_exception(fp)) { + ma_skipped++; + return; + } + + in_kernel = !user_mode(fp); + + isn = *(unsigned long *)(fp->ea); + + fault = 0; + + /* do fixup if in kernel or mode turned on */ + if (in_kernel || (ma_usermode & UM_FIXUP)) { + /* decompose instruction */ + a = (isn >> 27) & 0x1f; + b = (isn >> 22) & 0x1f; + imm16 = (isn >> 6) & 0xffff; + addr = get_reg_val(fp, a) + imm16; + + /* do fixup to saved registers */ + switch (isn & 0x3f) { + case INST_LDHU: + fault |= __get_user(d0, (u8 *)(addr+0)); + fault |= __get_user(d1, (u8 *)(addr+1)); + val = (d1 << 8) | d0; + put_reg_val(fp, b, val); + ma_half++; + break; + case INST_STH: + val = get_reg_val(fp, b); + d1 = val >> 8; + d0 = val >> 0; + + pr_debug("sth: ra=%d (%08x) rb=%d (%08x), imm16 %04x addr %08x val %08x\n", + a, get_reg_val(fp, a), + b, get_reg_val(fp, b), + imm16, addr, val); + + if (in_kernel) { + *(u8 *)(addr+0) = d0; + *(u8 *)(addr+1) = d1; + } else { + fault |= __put_user(d0, (u8 *)(addr+0)); + fault |= __put_user(d1, (u8 *)(addr+1)); + } + ma_half++; + break; + case INST_LDH: + fault |= __get_user(d0, (u8 *)(addr+0)); + fault |= __get_user(d1, (u8 *)(addr+1)); + val = (short)((d1 << 8) | d0); + put_reg_val(fp, b, val); + ma_half++; + break; + case INST_STW: + val = get_reg_val(fp, b); + d3 = val >> 24; + d2 = val >> 16; + d1 = val >> 8; + d0 = val >> 0; + if (in_kernel) { + *(u8 *)(addr+0) = d0; + *(u8 *)(addr+1) = d1; + *(u8 *)(addr+2) = d2; + *(u8 *)(addr+3) = d3; + } else { + fault |= __put_user(d0, (u8 *)(addr+0)); + fault |= __put_user(d1, (u8 *)(addr+1)); + fault |= __put_user(d2, (u8 *)(addr+2)); + fault |= __put_user(d3, (u8 *)(addr+3)); + } + ma_word++; + break; + case INST_LDW: + fault |= __get_user(d0, (u8 *)(addr+0)); + fault |= __get_user(d1, (u8 *)(addr+1)); + fault |= __get_user(d2, (u8 *)(addr+2)); + fault |= __get_user(d3, (u8 *)(addr+3)); + val = (d3 << 24) | (d2 << 16) | (d1 << 8) | d0; + put_reg_val(fp, b, val); + ma_word++; + break; + } + } + + addr = RDCTL(CTL_BADADDR); + cause >>= 2; + + if (fault) { + if (in_kernel) { + pr_err("fault during kernel misaligned fixup @ %#lx; addr 0x%08lx; isn=0x%08x\n", + fp->ea, (long unsigned int)addr, + (unsigned int)isn); + } else { + pr_err("fault during user misaligned fixup @ %#lx; isn=%08x addr=0x%08x sp=0x%08lx pid=%d\n", + fp->ea, + (unsigned int)isn, addr, fp->sp, + current->pid); + + _exception(SIGSEGV, fp, SEGV_MAPERR, fp->ea); + return; + } + } + + /* + * kernel mode - + * note exception and skip bad instruction (return) + */ + if (in_kernel) { + ma_kern++; + fp->ea += 4; + + if (ma_usermode & KM_WARN) { + pr_err("kernel unaligned access @ %#lx; BADADDR 0x%08lx; cause=%d, isn=0x%08lx\n", + fp->ea, + (long unsigned int)addr, cause, + (long unsigned int)isn); + /* show_regs(fp); */ + } + + return; + } + + ma_user++; + + /* + * user mode - + * possibly warn, + * possibly send SIGBUS signal to process + */ + if (ma_usermode & UM_WARN) { + pr_err("user unaligned access @ %#lx; isn=0x%08lx ea=0x%08lx ra=0x%08lx sp=0x%08lx\n", + (unsigned long)addr, (unsigned long)isn, + fp->ea, fp->ra, fp->sp); + } + + if (ma_usermode & UM_SIGNAL) + _exception(SIGBUS, fp, BUS_ADRALN, fp->ea); + else + fp->ea += 4; /* else advance */ +} + +#ifdef CONFIG_PROC_FS +static const char * const usermode_action[] = { + "ignored", /* 0 */ + "warn", /* 1 */ + "fixup", /* 2 */ + "fixup+warn", /* 3 */ + "signal", /* 4 */ + "signal+warn", /* 5 */ + "signal+fixup", + "signal+fixup+warn" +}; + +static int misaligned_proc_show(struct seq_file *m, void *v) +{ + seq_printf(m, "User:\t\t%lu\n", ma_user); + seq_printf(m, "Kernel:\t\t%lu\n", ma_kern); + seq_printf(m, "Skipped:\t%lu\n", ma_skipped); + seq_printf(m, "Half:\t\t%lu\n", ma_half); + seq_printf(m, "Word:\t\t%lu\n", ma_word); + seq_printf(m, "User faults:\t%i (%s)\n", ma_usermode, + usermode_action[ma_usermode & 7]); + + return 0; +} + +static int proc_misaligned_open(struct inode *inode, struct file *file) +{ + return single_open(file, misaligned_proc_show, NULL); +} + +static ssize_t proc_misaligned_write(struct file *file, + const char __user *buffer, + size_t count, loff_t *ppos) +{ + char mode; + + if (count > 0) { + if (get_user(mode, buffer)) + return -EFAULT; + if (mode >= '0' && mode <= '5') + ma_usermode = mode - '0'; + } + + return count; +} + +static const struct file_operations misalign_fops = { + .open = proc_misaligned_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, + .write = proc_misaligned_write, +}; +#endif /* CONFIG_PROC_FS */ + +static void __init misaligned_calc_reg_offsets(void) +{ + int i, r, offset; + + /* pre-calc offsets of registers on sys call stack frame */ + offset = 0; + + /* struct pt_regs */ + for (i = 0; i < 16; i++) { + r = sys_stack_frame_reg_offset[i]; + reg_offsets[r] = offset; + offset += 4; + } + + /* struct switch_stack */ + offset = -sizeof(struct switch_stack); + for (i = 16; i < 32; i++) { + r = sys_stack_frame_reg_offset[i]; + reg_offsets[r] = offset; + offset += 4; + } +} + + +static int __init misaligned_init(void) +{ +#ifdef CONFIG_PROC_FS + + struct proc_dir_entry *res; + + res = proc_create("misalign", S_IWUSR | S_IRUGO, NULL, &misalign_fops); + if (!res) + return -ENOMEM; +#endif + + /* default mode - silent fix */ + ma_usermode = UM_FIXUP | KM_WARN; + + misaligned_calc_reg_offsets(); + + return 0; +} + +fs_initcall(misaligned_init); -- 1.8.3.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/