diff options
Diffstat (limited to 'arch/sh/kernel/traps.c')
| -rw-r--r-- | arch/sh/kernel/traps.c | 751 |
1 files changed, 113 insertions, 638 deletions
diff --git a/arch/sh/kernel/traps.c b/arch/sh/kernel/traps.c index 7eb06719d84..dfdad72c61c 100644 --- a/arch/sh/kernel/traps.c +++ b/arch/sh/kernel/traps.c @@ -1,712 +1,187 @@ -/* $Id: traps.c,v 1.17 2004/05/02 01:46:30 sugioka Exp $ - * - * linux/arch/sh/traps.c - * - * SuperH version: Copyright (C) 1999 Niibe Yutaka - * Copyright (C) 2000 Philipp Rumpf - * Copyright (C) 2000 David Howells - * Copyright (C) 2002, 2003 Paul Mundt - */ - -/* - * 'Traps.c' handles hardware traps and faults after we have saved some - * state in 'entry.S'. - */ -#include <linux/config.h> +#include <linux/bug.h> +#include <linux/io.h> +#include <linux/types.h> +#include <linux/kdebug.h> +#include <linux/signal.h> #include <linux/sched.h> +#include <linux/uaccess.h> +#include <linux/hardirq.h> #include <linux/kernel.h> -#include <linux/string.h> -#include <linux/errno.h> -#include <linux/ptrace.h> -#include <linux/timer.h> -#include <linux/mm.h> -#include <linux/smp.h> -#include <linux/smp_lock.h> -#include <linux/init.h> -#include <linux/delay.h> -#include <linux/spinlock.h> +#include <linux/kexec.h> #include <linux/module.h> -#include <linux/kallsyms.h> - -#include <asm/system.h> -#include <asm/uaccess.h> -#include <asm/io.h> -#include <asm/atomic.h> -#include <asm/processor.h> -#include <asm/sections.h> - -#ifdef CONFIG_SH_KGDB -#include <asm/kgdb.h> -#define CHK_REMOTE_DEBUG(regs) \ -{ \ - if ((kgdb_debug_hook != (kgdb_debug_hook_t *) NULL) && (!user_mode(regs))) \ - { \ - (*kgdb_debug_hook)(regs); \ - } \ -} -#else -#define CHK_REMOTE_DEBUG(regs) -#endif - -#define DO_ERROR(trapnr, signr, str, name, tsk) \ -asmlinkage void do_##name(unsigned long r4, unsigned long r5, \ - unsigned long r6, unsigned long r7, \ - struct pt_regs regs) \ -{ \ - unsigned long error_code; \ - \ - /* Check if it's a DSP instruction */ \ - if (is_dsp_inst(®s)) { \ - /* Enable DSP mode, and restart instruction. */ \ - regs.sr |= SR_DSP; \ - return; \ - } \ - \ - asm volatile("stc r2_bank, %0": "=r" (error_code)); \ - local_irq_enable(); \ - tsk->thread.error_code = error_code; \ - tsk->thread.trap_no = trapnr; \ - CHK_REMOTE_DEBUG(®s); \ - force_sig(signr, tsk); \ - die_if_no_fixup(str,®s,error_code); \ -} +#include <asm/unwinder.h> +#include <asm/traps.h> -#ifdef CONFIG_CPU_SH2 -#define TRAP_RESERVED_INST 4 -#define TRAP_ILLEGAL_SLOT_INST 6 -#else -#define TRAP_RESERVED_INST 12 -#define TRAP_ILLEGAL_SLOT_INST 13 -#endif +static DEFINE_SPINLOCK(die_lock); -/* - * These constants are for searching for possible module text - * segments. VMALLOC_OFFSET comes from mm/vmalloc.c; MODULE_RANGE is - * a guess of how much space is likely to be vmalloced. - */ -#define VMALLOC_OFFSET (8*1024*1024) -#define MODULE_RANGE (8*1024*1024) - -spinlock_t die_lock; - -void die(const char * str, struct pt_regs * regs, long err) +void die(const char *str, struct pt_regs *regs, long err) { static int die_counter; - console_verbose(); + oops_enter(); + spin_lock_irq(&die_lock); + console_verbose(); + bust_spinlocks(1); + printk("%s: %04lx [#%d]\n", str, err & 0xffff, ++die_counter); - CHK_REMOTE_DEBUG(regs); + print_modules(); show_regs(regs); + + printk("Process: %s (pid: %d, stack limit = %p)\n", current->comm, + task_pid_nr(current), task_stack_page(current) + 1); + + if (!user_mode(regs) || in_interrupt()) + dump_mem("Stack: ", regs->regs[15], THREAD_SIZE + + (unsigned long)task_stack_page(current)); + + notify_die(DIE_OOPS, str, regs, err, 255, SIGSEGV); + + bust_spinlocks(0); + add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE); spin_unlock_irq(&die_lock); + oops_exit(); + + if (kexec_should_crash(current)) + crash_kexec(regs); + + if (in_interrupt()) + panic("Fatal exception in interrupt"); + + if (panic_on_oops) + panic("Fatal exception"); + do_exit(SIGSEGV); } -static inline void die_if_kernel(const char * str, struct pt_regs * regs, long err) +void die_if_kernel(const char *str, struct pt_regs *regs, long err) { if (!user_mode(regs)) die(str, regs, err); } -static int handle_unaligned_notify_count = 10; - /* * try and fix up kernelspace address errors * - userspace errors just cause EFAULT to be returned, resulting in SEGV * - kernel/userspace interfaces cause a jump to an appropriate handler * - other kernel errors are bad - * - return 0 if fixed-up, -EFAULT if non-fatal (to the kernel) fault */ -static int die_if_no_fixup(const char * str, struct pt_regs * regs, long err) +void die_if_no_fixup(const char *str, struct pt_regs *regs, long err) { - if (!user_mode(regs)) - { + if (!user_mode(regs)) { const struct exception_table_entry *fixup; fixup = search_exception_tables(regs->pc); if (fixup) { regs->pc = fixup->fixup; - return 0; + return; } + die(str, regs, err); } - return -EFAULT; } -/* - * handle an instruction that does an unaligned memory access by emulating the - * desired behaviour - * - note that PC _may not_ point to the faulting instruction - * (if that instruction is in a branch delay slot) - * - return 0 if emulation okay, -EFAULT on existential error - */ -static int handle_unaligned_ins(u16 instruction, struct pt_regs *regs) +#ifdef CONFIG_GENERIC_BUG +static void handle_BUG(struct pt_regs *regs) { - int ret, index, count; - unsigned long *rm, *rn; - unsigned char *src, *dst; - - index = (instruction>>8)&15; /* 0x0F00 */ - rn = ®s->regs[index]; - - index = (instruction>>4)&15; /* 0x00F0 */ - rm = ®s->regs[index]; - - count = 1<<(instruction&3); - - ret = -EFAULT; - switch (instruction>>12) { - case 0: /* mov.[bwl] to/from memory via r0+rn */ - if (instruction & 8) { - /* from memory */ - src = (unsigned char*) *rm; - src += regs->regs[0]; - dst = (unsigned char*) rn; - *(unsigned long*)dst = 0; - -#ifdef __LITTLE_ENDIAN__ - if (copy_from_user(dst, src, count)) - goto fetch_fault; - - if ((count == 2) && dst[1] & 0x80) { - dst[2] = 0xff; - dst[3] = 0xff; - } -#else - dst += 4-count; - - if (__copy_user(dst, src, count)) - goto fetch_fault; - - if ((count == 2) && dst[2] & 0x80) { - dst[0] = 0xff; - dst[1] = 0xff; - } -#endif - } else { - /* to memory */ - src = (unsigned char*) rm; -#if !defined(__LITTLE_ENDIAN__) - src += 4-count; -#endif - dst = (unsigned char*) *rn; - dst += regs->regs[0]; + const struct bug_entry *bug; + unsigned long bugaddr = regs->pc; + enum bug_trap_type tt; - if (copy_to_user(dst, src, count)) - goto fetch_fault; - } - ret = 0; - break; + if (!is_valid_bugaddr(bugaddr)) + goto invalid; - case 1: /* mov.l Rm,@(disp,Rn) */ - src = (unsigned char*) rm; - dst = (unsigned char*) *rn; - dst += (instruction&0x000F)<<2; - - if (copy_to_user(dst,src,4)) - goto fetch_fault; - ret = 0; - break; - - case 2: /* mov.[bwl] to memory, possibly with pre-decrement */ - if (instruction & 4) - *rn -= count; - src = (unsigned char*) rm; - dst = (unsigned char*) *rn; -#if !defined(__LITTLE_ENDIAN__) - src += 4-count; -#endif - if (copy_to_user(dst, src, count)) - goto fetch_fault; - ret = 0; - break; + bug = find_bug(bugaddr); - case 5: /* mov.l @(disp,Rm),Rn */ - src = (unsigned char*) *rm; - src += (instruction&0x000F)<<2; - dst = (unsigned char*) rn; - *(unsigned long*)dst = 0; - - if (copy_from_user(dst,src,4)) - goto fetch_fault; - ret = 0; - break; - - case 6: /* mov.[bwl] from memory, possibly with post-increment */ - src = (unsigned char*) *rm; - if (instruction & 4) - *rm += count; - dst = (unsigned char*) rn; - *(unsigned long*)dst = 0; - -#ifdef __LITTLE_ENDIAN__ - if (copy_from_user(dst, src, count)) - goto fetch_fault; - - if ((count == 2) && dst[1] & 0x80) { - dst[2] = 0xff; - dst[3] = 0xff; - } -#else - dst += 4-count; - - if (copy_from_user(dst, src, count)) - goto fetch_fault; - - if ((count == 2) && dst[2] & 0x80) { - dst[0] = 0xff; - dst[1] = 0xff; - } -#endif - ret = 0; - break; - - case 8: - switch ((instruction&0xFF00)>>8) { - case 0x81: /* mov.w R0,@(disp,Rn) */ - src = (unsigned char*) ®s->regs[0]; -#if !defined(__LITTLE_ENDIAN__) - src += 2; -#endif - dst = (unsigned char*) *rm; /* called Rn in the spec */ - dst += (instruction&0x000F)<<1; - - if (copy_to_user(dst, src, 2)) - goto fetch_fault; - ret = 0; - break; - - case 0x85: /* mov.w @(disp,Rm),R0 */ - src = (unsigned char*) *rm; - src += (instruction&0x000F)<<1; - dst = (unsigned char*) ®s->regs[0]; - *(unsigned long*)dst = 0; - -#if !defined(__LITTLE_ENDIAN__) - dst += 2; -#endif + /* Switch unwinders when unwind_stack() is called */ + if (bug->flags & BUGFLAG_UNWINDER) + unwinder_faulted = 1; - if (copy_from_user(dst, src, 2)) - goto fetch_fault; - -#ifdef __LITTLE_ENDIAN__ - if (dst[1] & 0x80) { - dst[2] = 0xff; - dst[3] = 0xff; - } -#else - if (dst[2] & 0x80) { - dst[0] = 0xff; - dst[1] = 0xff; - } -#endif - ret = 0; - break; - } - break; + tt = report_bug(bugaddr, regs); + if (tt == BUG_TRAP_TYPE_WARN) { + regs->pc += instruction_size(bugaddr); + return; } - return ret; - fetch_fault: - /* Argh. Address not only misaligned but also non-existent. - * Raise an EFAULT and see if it's trapped - */ - return die_if_no_fixup("Fault in unaligned fixup", regs, 0); +invalid: + die("Kernel BUG", regs, TRAPA_BUG_OPCODE & 0xff); } -/* - * emulate the instruction in the delay slot - * - fetches the instruction from PC+2 - */ -static inline int handle_unaligned_delayslot(struct pt_regs *regs) +int is_valid_bugaddr(unsigned long addr) { - u16 instruction; - - if (copy_from_user(&instruction, (u16 *)(regs->pc+2), 2)) { - /* the instruction-fetch faulted */ - if (user_mode(regs)) - return -EFAULT; + insn_size_t opcode; - /* kernel */ - die("delay-slot-insn faulting in handle_unaligned_delayslot", regs, 0); - } + if (addr < PAGE_OFFSET) + return 0; + if (probe_kernel_address((insn_size_t *)addr, opcode)) + return 0; + if (opcode == TRAPA_BUG_OPCODE) + return 1; - return handle_unaligned_ins(instruction,regs); + return 0; } - -/* - * handle an instruction that does an unaligned memory access - * - have to be careful of branch delay-slot instructions that fault - * SH3: - * - if the branch would be taken PC points to the branch - * - if the branch would not be taken, PC points to delay-slot - * SH4: - * - PC always points to delayed branch - * - return 0 if handled, -EFAULT if failed (may not return if in kernel) - */ - -/* Macros to determine offset from current PC for branch instructions */ -/* Explicit type coercion is used to force sign extension where needed */ -#define SH_PC_8BIT_OFFSET(instr) ((((signed char)(instr))*2) + 4) -#define SH_PC_12BIT_OFFSET(instr) ((((signed short)(instr<<4))>>3) + 4) - -static int handle_unaligned_access(u16 instruction, struct pt_regs *regs) -{ - u_int rm; - int ret, index; - - index = (instruction>>8)&15; /* 0x0F00 */ - rm = regs->regs[index]; - - /* shout about the first ten userspace fixups */ - if (user_mode(regs) && handle_unaligned_notify_count>0) { - handle_unaligned_notify_count--; - - printk("Fixing up unaligned userspace access in \"%s\" pid=%d pc=0x%p ins=0x%04hx\n", - current->comm,current->pid,(u16*)regs->pc,instruction); - } - - ret = -EFAULT; - switch (instruction&0xF000) { - case 0x0000: - if (instruction==0x000B) { - /* rts */ - ret = handle_unaligned_delayslot(regs); - if (ret==0) - regs->pc = regs->pr; - } - else if ((instruction&0x00FF)==0x0023) { - /* braf @Rm */ - ret = handle_unaligned_delayslot(regs); - if (ret==0) - regs->pc += rm + 4; - } - else if ((instruction&0x00FF)==0x0003) { - /* bsrf @Rm */ - ret = handle_unaligned_delayslot(regs); - if (ret==0) { - regs->pr = regs->pc + 4; - regs->pc += rm + 4; - } - } - else { - /* mov.[bwl] to/from memory via r0+rn */ - goto simple; - } - break; - - case 0x1000: /* mov.l Rm,@(disp,Rn) */ - goto simple; - - case 0x2000: /* mov.[bwl] to memory, possibly with pre-decrement */ - goto simple; - - case 0x4000: - if ((instruction&0x00FF)==0x002B) { - /* jmp @Rm */ - ret = handle_unaligned_delayslot(regs); - if (ret==0) - regs->pc = rm; - } - else if ((instruction&0x00FF)==0x000B) { - /* jsr @Rm */ - ret = handle_unaligned_delayslot(regs); - if (ret==0) { - regs->pr = regs->pc + 4; - regs->pc = rm; - } - } - else { - /* mov.[bwl] to/from memory via r0+rn */ - goto simple; - } - break; - - case 0x5000: /* mov.l @(disp,Rm),Rn */ - goto simple; - - case 0x6000: /* mov.[bwl] from memory, possibly with post-increment */ - goto simple; - - case 0x8000: /* bf lab, bf/s lab, bt lab, bt/s lab */ - switch (instruction&0x0F00) { - case 0x0100: /* mov.w R0,@(disp,Rm) */ - goto simple; - case 0x0500: /* mov.w @(disp,Rm),R0 */ - goto simple; - case 0x0B00: /* bf lab - no delayslot*/ - break; - case 0x0F00: /* bf/s lab */ - ret = handle_unaligned_delayslot(regs); - if (ret==0) { -#if defined(CONFIG_CPU_SH4) || defined(CONFIG_SH7705_CACHE_32KB) - if ((regs->sr & 0x00000001) != 0) - regs->pc += 4; /* next after slot */ - else #endif - regs->pc += SH_PC_8BIT_OFFSET(instruction); - } - break; - case 0x0900: /* bt lab - no delayslot */ - break; - case 0x0D00: /* bt/s lab */ - ret = handle_unaligned_delayslot(regs); - if (ret==0) { -#if defined(CONFIG_CPU_SH4) || defined(CONFIG_SH7705_CACHE_32KB) - if ((regs->sr & 0x00000001) == 0) - regs->pc += 4; /* next after slot */ - else -#endif - regs->pc += SH_PC_8BIT_OFFSET(instruction); - } - break; - } - break; - - case 0xA000: /* bra label */ - ret = handle_unaligned_delayslot(regs); - if (ret==0) - regs->pc += SH_PC_12BIT_OFFSET(instruction); - break; - - case 0xB000: /* bsr label */ - ret = handle_unaligned_delayslot(regs); - if (ret==0) { - regs->pr = regs->pc + 4; - regs->pc += SH_PC_12BIT_OFFSET(instruction); - } - break; - } - return ret; - - /* handle non-delay-slot instruction */ - simple: - ret = handle_unaligned_ins(instruction,regs); - if (ret==0) - regs->pc += 2; - return ret; -} /* - * Handle various address error exceptions + * Generic trap handler. */ -asmlinkage void do_address_error(struct pt_regs *regs, - unsigned long writeaccess, - unsigned long address) +BUILD_TRAP_HANDLER(debug) { - unsigned long error_code; - mm_segment_t oldfs; - u16 instruction; - int tmp; - - asm volatile("stc r2_bank,%0": "=r" (error_code)); - - oldfs = get_fs(); - - if (user_mode(regs)) { - local_irq_enable(); - current->thread.error_code = error_code; - current->thread.trap_no = (writeaccess) ? 8 : 7; - - /* bad PC is not something we can fix */ - if (regs->pc & 1) - goto uspace_segv; - - set_fs(USER_DS); - if (copy_from_user(&instruction, (u16 *)(regs->pc), 2)) { - /* Argh. Fault on the instruction itself. - This should never happen non-SMP - */ - set_fs(oldfs); - goto uspace_segv; - } + TRAP_HANDLER_DECL; - tmp = handle_unaligned_access(instruction, regs); - set_fs(oldfs); - - if (tmp==0) - return; /* sorted */ - - uspace_segv: - printk(KERN_NOTICE "Killing process \"%s\" due to unaligned access\n", current->comm); - force_sig(SIGSEGV, current); - } else { - if (regs->pc & 1) - die("unaligned program counter", regs, error_code); - - set_fs(KERNEL_DS); - if (copy_from_user(&instruction, (u16 *)(regs->pc), 2)) { - /* Argh. Fault on the instruction itself. - This should never happen non-SMP - */ - set_fs(oldfs); - die("insn faulting in do_address_error", regs, 0); - } + /* Rewind */ + regs->pc -= instruction_size(__raw_readw(regs->pc - 4)); - handle_unaligned_access(instruction, regs); - set_fs(oldfs); - } + if (notify_die(DIE_TRAP, "debug trap", regs, 0, vec & 0xff, + SIGTRAP) == NOTIFY_STOP) + return; + + force_sig(SIGTRAP, current); } -#ifdef CONFIG_SH_DSP /* - * SH-DSP support gerg@snapgear.com. + * Special handler for BUG() traps. */ -int is_dsp_inst(struct pt_regs *regs) -{ - unsigned short inst; - - /* - * Safe guard if DSP mode is already enabled or we're lacking - * the DSP altogether. - */ - if (!(cpu_data->flags & CPU_HAS_DSP) || (regs->sr & SR_DSP)) - return 0; - - get_user(inst, ((unsigned short *) regs->pc)); - - inst &= 0xf000; - - /* Check for any type of DSP or support instruction */ - if ((inst == 0xf000) || (inst == 0x4000)) - return 1; - - return 0; -} -#else -#define is_dsp_inst(regs) (0) -#endif /* CONFIG_SH_DSP */ - -DO_ERROR(TRAP_RESERVED_INST, SIGILL, "reserved instruction", reserved_inst, current) -DO_ERROR(TRAP_ILLEGAL_SLOT_INST, SIGILL, "illegal slot instruction", illegal_slot_inst, current) - -asmlinkage void do_exception_error(unsigned long r4, unsigned long r5, - unsigned long r6, unsigned long r7, - struct pt_regs regs) +BUILD_TRAP_HANDLER(bug) { - long ex; - asm volatile("stc r2_bank, %0" : "=r" (ex)); - die_if_kernel("exception", ®s, ex); -} + TRAP_HANDLER_DECL; -#if defined(CONFIG_SH_STANDARD_BIOS) -void *gdb_vbr_vector; + /* Rewind */ + regs->pc -= instruction_size(__raw_readw(regs->pc - 4)); -static inline void __init gdb_vbr_init(void) -{ - register unsigned long vbr; - - /* - * Read the old value of the VBR register to initialise - * the vector through which debug and BIOS traps are - * delegated by the Linux trap handler. - */ - asm volatile("stc vbr, %0" : "=r" (vbr)); - - gdb_vbr_vector = (void *)(vbr + 0x100); - printk("Setting GDB trap vector to 0x%08lx\n", - (unsigned long)gdb_vbr_vector); -} -#endif + if (notify_die(DIE_TRAP, "bug trap", regs, 0, TRAPA_BUG_OPCODE & 0xff, + SIGTRAP) == NOTIFY_STOP) + return; -void __init per_cpu_trap_init(void) -{ - extern void *vbr_base; - -#ifdef CONFIG_SH_STANDARD_BIOS - gdb_vbr_init(); +#ifdef CONFIG_GENERIC_BUG + if (__kernel_text_address(instruction_pointer(regs))) { + insn_size_t insn = *(insn_size_t *)instruction_pointer(regs); + if (insn == TRAPA_BUG_OPCODE) + handle_BUG(regs); + return; + } #endif - /* NOTE: The VBR value should be at P1 - (or P2, virtural "fixed" address space). - It's definitely should not in physical address. */ - - asm volatile("ldc %0, vbr" - : /* no output */ - : "r" (&vbr_base) - : "memory"); + force_sig(SIGTRAP, current); } -void __init trap_init(void) +BUILD_TRAP_HANDLER(nmi) { - extern void *exception_handling_table[]; - - exception_handling_table[TRAP_RESERVED_INST] - = (void *)do_reserved_inst; - exception_handling_table[TRAP_ILLEGAL_SLOT_INST] - = (void *)do_illegal_slot_inst; - -#ifdef CONFIG_CPU_SH4 - if (!(cpu_data->flags & CPU_HAS_FPU)) { - /* For SH-4 lacking an FPU, treat floating point instructions - as reserved. */ - /* entry 64 corresponds to EXPEVT=0x800 */ - exception_handling_table[64] = (void *)do_reserved_inst; - exception_handling_table[65] = (void *)do_illegal_slot_inst; - } -#endif - - /* Setup VBR for boot cpu */ - per_cpu_trap_init(); -} + unsigned int cpu = smp_processor_id(); + TRAP_HANDLER_DECL; -void show_stack(struct task_struct *tsk, unsigned long *sp) -{ - unsigned long *stack, addr; - unsigned long module_start = VMALLOC_START; - unsigned long module_end = VMALLOC_END; - int i = 1; + nmi_enter(); + nmi_count(cpu)++; - if (tsk && !sp) { - sp = (unsigned long *)tsk->thread.sp; - } - - if (!sp) { - __asm__ __volatile__ ( - "mov r15, %0\n\t" - "stc r7_bank, %1\n\t" - : "=r" (module_start), - "=r" (module_end) - ); - - sp = (unsigned long *)module_start; - } - - stack = sp; - - printk("\nCall trace: "); -#ifdef CONFIG_KALLSYMS - printk("\n"); -#endif - - while (!kstack_end(stack)) { - addr = *stack++; - if (((addr >= (unsigned long)_text) && - (addr <= (unsigned long)_etext)) || - ((addr >= module_start) && (addr <= module_end))) { - /* - * For 80-columns display, 6 entry is maximum. - * NOTE: '[<8c00abcd>] ' consumes 13 columns . - */ -#ifndef CONFIG_KALLSYMS - if (i && ((i % 6) == 0)) - printk("\n "); -#endif - printk("[<%08lx>] ", addr); - print_symbol("%s\n", addr); - i++; - } + switch (notify_die(DIE_NMI, "NMI", regs, 0, vec & 0xff, SIGINT)) { + case NOTIFY_OK: + case NOTIFY_STOP: + break; + case NOTIFY_BAD: + die("Fatal Non-Maskable Interrupt", regs, SIGINT); + default: + printk(KERN_ALERT "Got NMI, but nobody cared. Ignoring...\n"); + break; } - printk("\n"); -} - -void show_task(unsigned long *sp) -{ - show_stack(NULL, sp); -} - -void dump_stack(void) -{ - show_stack(NULL, NULL); + nmi_exit(); } -EXPORT_SYMBOL(dump_stack); |