diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/arm26/kernel/traps.c |
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'arch/arm26/kernel/traps.c')
-rw-r--r-- | arch/arm26/kernel/traps.c | 548 |
1 files changed, 548 insertions, 0 deletions
diff --git a/arch/arm26/kernel/traps.c b/arch/arm26/kernel/traps.c new file mode 100644 index 00000000000..f64f5902239 --- /dev/null +++ b/arch/arm26/kernel/traps.c @@ -0,0 +1,548 @@ +/* + * linux/arch/arm26/kernel/traps.c + * + * Copyright (C) 1995-2002 Russell King + * Fragments that appear the same as linux/arch/i386/kernel/traps.c (C) Linus Torvalds + * Copyright (C) 2003 Ian Molton (ARM26) + * + * 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. + * + * 'traps.c' handles hardware exceptions after we have saved some state in + * 'linux/arch/arm26/lib/traps.S'. Mostly a debugging aid, but will probably + * kill the offending process. + */ + +#include <linux/module.h> +#include <linux/config.h> +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/signal.h> +#include <linux/sched.h> +#include <linux/mm.h> +#include <linux/spinlock.h> +#include <linux/personality.h> +#include <linux/ptrace.h> +#include <linux/elf.h> +#include <linux/interrupt.h> +#include <linux/init.h> + +#include <asm/atomic.h> +#include <asm/io.h> +#include <asm/pgtable.h> +#include <asm/system.h> +#include <asm/uaccess.h> +#include <asm/unistd.h> +#include <asm/semaphore.h> + +#include "ptrace.h" + +extern void c_backtrace (unsigned long fp, int pmode); +extern void show_pte(struct mm_struct *mm, unsigned long addr); + +const char *processor_modes[] = { "USER_26", "FIQ_26" , "IRQ_26" , "SVC_26" }; + +static const char *handler[]= { "prefetch abort", "data abort", "address exception", "interrupt" "*bad reason*"}; + +/* + * Stack pointers should always be within the kernels view of + * physical memory. If it is not there, then we can't dump + * out any information relating to the stack. + */ +static int verify_stack(unsigned long sp) +{ + if (sp < PAGE_OFFSET || (sp > (unsigned long)high_memory && high_memory != 0)) + return -EFAULT; + + return 0; +} + +/* + * Dump out the contents of some memory nicely... + */ +static void dump_mem(const char *str, unsigned long bottom, unsigned long top) +{ + unsigned long p = bottom & ~31; + mm_segment_t fs; + int i; + + /* + * We need to switch to kernel mode so that we can use __get_user + * to safely read from kernel space. Note that we now dump the + * code first, just in case the backtrace kills us. + */ + fs = get_fs(); + set_fs(KERNEL_DS); + + printk("%s", str); + printk("(0x%08lx to 0x%08lx)\n", bottom, top); + + for (p = bottom & ~31; p < top;) { + printk("%04lx: ", p & 0xffff); + + for (i = 0; i < 8; i++, p += 4) { + unsigned int val; + + if (p < bottom || p >= top) + printk(" "); + else { + __get_user(val, (unsigned long *)p); + printk("%08x ", val); + } + } + printk ("\n"); + } + + set_fs(fs); +} + +static void dump_instr(struct pt_regs *regs) +{ + unsigned long addr = instruction_pointer(regs); + const int width = 8; + mm_segment_t fs; + int i; + + /* + * We need to switch to kernel mode so that we can use __get_user + * to safely read from kernel space. Note that we now dump the + * code first, just in case the backtrace kills us. + */ + fs = get_fs(); + set_fs(KERNEL_DS); + + printk("Code: "); + for (i = -4; i < 1; i++) { + unsigned int val, bad; + + bad = __get_user(val, &((u32 *)addr)[i]); + + if (!bad) + printk(i == 0 ? "(%0*x) " : "%0*x ", width, val); + else { + printk("bad PC value."); + break; + } + } + printk("\n"); + + set_fs(fs); +} + +/*static*/ void __dump_stack(struct task_struct *tsk, unsigned long sp) +{ + dump_mem("Stack: ", sp, 8192+(unsigned long)tsk->thread_info); +} + +void dump_stack(void) +{ +#ifdef CONFIG_DEBUG_ERRORS + __backtrace(); +#endif +} + +EXPORT_SYMBOL(dump_stack); + +//FIXME - was a static fn +void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk) +{ + unsigned int fp; + int ok = 1; + + printk("Backtrace: "); + fp = regs->ARM_fp; + if (!fp) { + printk("no frame pointer"); + ok = 0; + } else if (verify_stack(fp)) { + printk("invalid frame pointer 0x%08x", fp); + ok = 0; + } else if (fp < (unsigned long)(tsk->thread_info + 1)) + printk("frame pointer underflow"); + printk("\n"); + + if (ok) + c_backtrace(fp, processor_mode(regs)); +} + +/* FIXME - this is probably wrong.. */ +void show_stack(struct task_struct *task, unsigned long *sp) { + dump_mem("Stack: ", (unsigned long)sp, 8192+(unsigned long)task->thread_info); +} + +DEFINE_SPINLOCK(die_lock); + +/* + * This function is protected against re-entrancy. + */ +NORET_TYPE void die(const char *str, struct pt_regs *regs, int err) +{ + struct task_struct *tsk = current; + + console_verbose(); + spin_lock_irq(&die_lock); + + printk("Internal error: %s: %x\n", str, err); + printk("CPU: %d\n", smp_processor_id()); + show_regs(regs); + printk("Process %s (pid: %d, stack limit = 0x%p)\n", + current->comm, current->pid, tsk->thread_info + 1); + + if (!user_mode(regs) || in_interrupt()) { + __dump_stack(tsk, (unsigned long)(regs + 1)); + dump_backtrace(regs, tsk); + dump_instr(regs); + } +while(1); + spin_unlock_irq(&die_lock); + do_exit(SIGSEGV); +} + +void die_if_kernel(const char *str, struct pt_regs *regs, int err) +{ + if (user_mode(regs)) + return; + + die(str, regs, err); +} + +static DECLARE_MUTEX(undef_sem); +static int (*undef_hook)(struct pt_regs *); + +int request_undef_hook(int (*fn)(struct pt_regs *)) +{ + int ret = -EBUSY; + + down(&undef_sem); + if (undef_hook == NULL) { + undef_hook = fn; + ret = 0; + } + up(&undef_sem); + + return ret; +} + +int release_undef_hook(int (*fn)(struct pt_regs *)) +{ + int ret = -EINVAL; + + down(&undef_sem); + if (undef_hook == fn) { + undef_hook = NULL; + ret = 0; + } + up(&undef_sem); + + return ret; +} + +static int undefined_extension(struct pt_regs *regs, unsigned int op) +{ + switch (op) { + case 1: /* 0xde01 / 0x?7f001f0 */ + ptrace_break(current, regs); + return 0; + } + return 1; +} + +asmlinkage void do_undefinstr(struct pt_regs *regs) +{ + siginfo_t info; + void *pc; + + regs->ARM_pc -= 4; + + pc = (unsigned long *)instruction_pointer(regs); /* strip PSR */ + + if (user_mode(regs)) { + u32 instr; + + get_user(instr, (u32 *)pc); + + if ((instr & 0x0fff00ff) == 0x07f000f0 && + undefined_extension(regs, (instr >> 8) & 255) == 0) { + regs->ARM_pc += 4; + return; + } + } else { + if (undef_hook && undef_hook(regs) == 0) { + regs->ARM_pc += 4; + return; + } + } + +#ifdef CONFIG_DEBUG_USER + printk(KERN_INFO "%s (%d): undefined instruction: pc=%p\n", + current->comm, current->pid, pc); + dump_instr(regs); +#endif + + current->thread.error_code = 0; + current->thread.trap_no = 6; + + info.si_signo = SIGILL; + info.si_errno = 0; + info.si_code = ILL_ILLOPC; + info.si_addr = pc; + + force_sig_info(SIGILL, &info, current); + + die_if_kernel("Oops - undefined instruction", regs, 0); +} + +asmlinkage void do_excpt(unsigned long address, struct pt_regs *regs, int mode) +{ + siginfo_t info; + +#ifdef CONFIG_DEBUG_USER + printk(KERN_INFO "%s (%d): address exception: pc=%08lx\n", + current->comm, current->pid, instruction_pointer(regs)); + dump_instr(regs); +#endif + + current->thread.error_code = 0; + current->thread.trap_no = 11; + + info.si_signo = SIGBUS; + info.si_errno = 0; + info.si_code = BUS_ADRERR; + info.si_addr = (void *)address; + + force_sig_info(SIGBUS, &info, current); + + die_if_kernel("Oops - address exception", regs, mode); +} + +asmlinkage void do_unexp_fiq (struct pt_regs *regs) +{ +#ifndef CONFIG_IGNORE_FIQ + printk("Hmm. Unexpected FIQ received, but trying to continue\n"); + printk("You may have a hardware problem...\n"); +#endif +} + +/* + * bad_mode handles the impossible case in the vectors. If you see one of + * these, then it's extremely serious, and could mean you have buggy hardware. + * It never returns, and never tries to sync. We hope that we can at least + * dump out some state information... + */ +asmlinkage void bad_mode(struct pt_regs *regs, int reason, int proc_mode) +{ + unsigned int vectors = vectors_base(); + + console_verbose(); + + printk(KERN_CRIT "Bad mode in %s handler detected: mode %s\n", + handler[reason<5?reason:4], processor_modes[proc_mode]); + + /* + * Dump out the vectors and stub routines. Maybe a better solution + * would be to dump them out only if we detect that they are corrupted. + */ + dump_mem(KERN_CRIT "Vectors: ", vectors, vectors + 0x40); + dump_mem(KERN_CRIT "Stubs: ", vectors + 0x200, vectors + 0x4b8); + + die("Oops", regs, 0); + local_irq_disable(); + panic("bad mode"); +} + +static int bad_syscall(int n, struct pt_regs *regs) +{ + struct thread_info *thread = current_thread_info(); + siginfo_t info; + + if (current->personality != PER_LINUX && thread->exec_domain->handler) { + thread->exec_domain->handler(n, regs); + return regs->ARM_r0; + } + +#ifdef CONFIG_DEBUG_USER + printk(KERN_ERR "[%d] %s: obsolete system call %08x.\n", + current->pid, current->comm, n); + dump_instr(regs); +#endif + + info.si_signo = SIGILL; + info.si_errno = 0; + info.si_code = ILL_ILLTRP; + info.si_addr = (void *)instruction_pointer(regs) - 4; + + force_sig_info(SIGILL, &info, current); + die_if_kernel("Oops", regs, n); + return regs->ARM_r0; +} + +static inline void +do_cache_op(unsigned long start, unsigned long end, int flags) +{ + struct vm_area_struct *vma; + + if (end < start) + return; + + vma = find_vma(current->active_mm, start); + if (vma && vma->vm_start < end) { + if (start < vma->vm_start) + start = vma->vm_start; + if (end > vma->vm_end) + end = vma->vm_end; + } +} + +/* + * Handle all unrecognised system calls. + * 0x9f0000 - 0x9fffff are some more esoteric system calls + */ +#define NR(x) ((__ARM_NR_##x) - __ARM_NR_BASE) +asmlinkage int arm_syscall(int no, struct pt_regs *regs) +{ + siginfo_t info; + + if ((no >> 16) != 0x9f) + return bad_syscall(no, regs); + + switch (no & 0xffff) { + case 0: /* branch through 0 */ + info.si_signo = SIGSEGV; + info.si_errno = 0; + info.si_code = SEGV_MAPERR; + info.si_addr = NULL; + + force_sig_info(SIGSEGV, &info, current); + + die_if_kernel("branch through zero", regs, 0); + return 0; + + case NR(breakpoint): /* SWI BREAK_POINT */ + ptrace_break(current, regs); + return regs->ARM_r0; + + case NR(cacheflush): + return 0; + + case NR(usr26): + break; + + default: + /* Calls 9f00xx..9f07ff are defined to return -ENOSYS + if not implemented, rather than raising SIGILL. This + way the calling program can gracefully determine whether + a feature is supported. */ + if (no <= 0x7ff) + return -ENOSYS; + break; + } +#ifdef CONFIG_DEBUG_USER + /* + * experience shows that these seem to indicate that + * something catastrophic has happened + */ + printk("[%d] %s: arm syscall %d\n", current->pid, current->comm, no); + dump_instr(regs); + if (user_mode(regs)) { + show_regs(regs); + c_backtrace(regs->ARM_fp, processor_mode(regs)); + } +#endif + info.si_signo = SIGILL; + info.si_errno = 0; + info.si_code = ILL_ILLTRP; + info.si_addr = (void *)instruction_pointer(regs) - 4; + + force_sig_info(SIGILL, &info, current); + die_if_kernel("Oops", regs, no); + return 0; +} + +void __bad_xchg(volatile void *ptr, int size) +{ + printk("xchg: bad data size: pc 0x%p, ptr 0x%p, size %d\n", + __builtin_return_address(0), ptr, size); + BUG(); +} + +/* + * A data abort trap was taken, but we did not handle the instruction. + * Try to abort the user program, or panic if it was the kernel. + */ +asmlinkage void +baddataabort(int code, unsigned long instr, struct pt_regs *regs) +{ + unsigned long addr = instruction_pointer(regs); + siginfo_t info; + +#ifdef CONFIG_DEBUG_USER + printk(KERN_ERR "[%d] %s: bad data abort: code %d instr 0x%08lx\n", + current->pid, current->comm, code, instr); + dump_instr(regs); + show_pte(current->mm, addr); +#endif + + info.si_signo = SIGILL; + info.si_errno = 0; + info.si_code = ILL_ILLOPC; + info.si_addr = (void *)addr; + + force_sig_info(SIGILL, &info, current); + die_if_kernel("unknown data abort code", regs, instr); +} + +volatile void __bug(const char *file, int line, void *data) +{ + printk(KERN_CRIT"kernel BUG at %s:%d!", file, line); + if (data) + printk(KERN_CRIT" - extra data = %p", data); + printk("\n"); + *(int *)0 = 0; +} + +void __readwrite_bug(const char *fn) +{ + printk("%s called, but not implemented", fn); + BUG(); +} + +void __pte_error(const char *file, int line, unsigned long val) +{ + printk("%s:%d: bad pte %08lx.\n", file, line, val); +} + +void __pmd_error(const char *file, int line, unsigned long val) +{ + printk("%s:%d: bad pmd %08lx.\n", file, line, val); +} + +void __pgd_error(const char *file, int line, unsigned long val) +{ + printk("%s:%d: bad pgd %08lx.\n", file, line, val); +} + +asmlinkage void __div0(void) +{ + printk("Division by zero in kernel.\n"); + dump_stack(); +} + +void abort(void) +{ + BUG(); + + /* if that doesn't kill us, halt */ + panic("Oops failed to kill thread"); +} + +void __init trap_init(void) +{ + extern void __trap_init(unsigned long); + unsigned long base = vectors_base(); + + __trap_init(base); + if (base != 0) + printk(KERN_DEBUG "Relocating machine vectors to 0x%08lx\n", + base); +} |