From 623b0355d5b1f9c6d05005b649a2f3a7b9fd7816 Mon Sep 17 00:00:00 2001 From: Haavard Skinnemoen Date: Tue, 13 Mar 2007 17:59:11 +0100 Subject: [AVR32] Clean up exception handling code * Use generic BUG() handling * Remove some useless debug statements * Use a common function _exception() to send signals or oops when an exception can't be handled. This makes sure init doesn't enter an infinite exception loop as well. Borrowed from powerpc. * Add some basic exception tracing support to the page fault code. * Rework dump_stack(), show_regs() and friends and move everything into process.c * Print information about configuration options and chip type when oopsing Signed-off-by: Haavard Skinnemoen --- arch/avr32/kernel/traps.c | 421 ++++++++++++++-------------------------------- 1 file changed, 127 insertions(+), 294 deletions(-) (limited to 'arch/avr32/kernel/traps.c') diff --git a/arch/avr32/kernel/traps.c b/arch/avr32/kernel/traps.c index adc01a12d154..4f0382d8483f 100644 --- a/arch/avr32/kernel/traps.c +++ b/arch/avr32/kernel/traps.c @@ -5,158 +5,25 @@ * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ -#undef DEBUG -#include + +#include #include -#include #include +#include #include +#include +#include -#include -#include #include -#include #include -#include - -static void dump_mem(const char *str, unsigned long bottom, unsigned long top) -{ - unsigned long p; - int i; - - printk("%s(0x%08lx to 0x%08lx)\n", str, 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 { - if (__get_user(val, (unsigned int __user *)p)) { - printk("\n"); - goto out; - } - printk("%08x ", val); - } - } - printk("\n"); - } - -out: - return; -} - -static inline int valid_stack_ptr(struct thread_info *tinfo, unsigned long p) -{ - return (p > (unsigned long)tinfo) - && (p < (unsigned long)tinfo + THREAD_SIZE - 3); -} - -#ifdef CONFIG_FRAME_POINTER -static inline void __show_trace(struct task_struct *tsk, unsigned long *sp, - struct pt_regs *regs) -{ - unsigned long lr, fp; - struct thread_info *tinfo; - - tinfo = (struct thread_info *) - ((unsigned long)sp & ~(THREAD_SIZE - 1)); - - if (regs) - fp = regs->r7; - else if (tsk == current) - asm("mov %0, r7" : "=r"(fp)); - else - fp = tsk->thread.cpu_context.r7; - - /* - * Walk the stack as long as the frame pointer (a) is within - * the kernel stack of the task, and (b) it doesn't move - * downwards. - */ - while (valid_stack_ptr(tinfo, fp)) { - unsigned long new_fp; - - lr = *(unsigned long *)fp; - printk(" [<%08lx>] ", lr); - print_symbol("%s\n", lr); - - new_fp = *(unsigned long *)(fp + 4); - if (new_fp <= fp) - break; - fp = new_fp; - } - printk("\n"); -} -#else -static inline void __show_trace(struct task_struct *tsk, unsigned long *sp, - struct pt_regs *regs) -{ - unsigned long addr; - - while (!kstack_end(sp)) { - addr = *sp++; - if (kernel_text_address(addr)) { - printk(" [<%08lx>] ", addr); - print_symbol("%s\n", addr); - } - } -} -#endif - -void show_trace(struct task_struct *tsk, unsigned long *sp, - struct pt_regs *regs) -{ - if (regs && - (((regs->sr & MODE_MASK) == MODE_EXCEPTION) || - ((regs->sr & MODE_MASK) == MODE_USER))) - return; - - printk ("Call trace:"); -#ifdef CONFIG_KALLSYMS - printk("\n"); -#endif - - __show_trace(tsk, sp, regs); - printk("\n"); -} - -void show_stack(struct task_struct *tsk, unsigned long *sp) -{ - unsigned long stack; - - if (!tsk) - tsk = current; - if (sp == 0) { - if (tsk == current) { - register unsigned long *real_sp __asm__("sp"); - sp = real_sp; - } else { - sp = (unsigned long *)tsk->thread.cpu_context.ksp; - } - } - - stack = (unsigned long)sp; - dump_mem("Stack: ", stack, - THREAD_SIZE + (unsigned long)tsk->thread_info); - show_trace(tsk, sp, NULL); -} - -void dump_stack(void) -{ - show_stack(NULL, NULL); -} -EXPORT_SYMBOL(dump_stack); +#include +#include +#include ATOMIC_NOTIFIER_HEAD(avr32_die_chain); int register_die_notifier(struct notifier_block *nb) { - pr_debug("register_die_notifier: %p\n", nb); - return atomic_notifier_chain_register(&avr32_die_chain, nb); } EXPORT_SYMBOL(register_die_notifier); @@ -169,93 +36,103 @@ EXPORT_SYMBOL(unregister_die_notifier); static DEFINE_SPINLOCK(die_lock); -void __die(const char *str, struct pt_regs *regs, unsigned long err, - const char *file, const char *func, unsigned long line) +void NORET_TYPE die(const char *str, struct pt_regs *regs, long err) { - struct task_struct *tsk = current; static int die_counter; console_verbose(); spin_lock_irq(&die_lock); bust_spinlocks(1); - printk(KERN_ALERT "%s", str); - if (file && func) - printk(" in %s:%s, line %ld", file, func, line); - printk("[#%d]:\n", ++die_counter); - print_modules(); - show_regs(regs); - printk("Process %s (pid: %d, stack limit = 0x%p)\n", - tsk->comm, tsk->pid, tsk->thread_info + 1); - - if (!user_mode(regs) || in_interrupt()) { - dump_mem("Stack: ", regs->sp, - THREAD_SIZE + (unsigned long)tsk->thread_info); + printk(KERN_ALERT "Oops: %s, sig: %ld [#%d]\n" KERN_EMERG, + str, err, ++die_counter); +#ifdef CONFIG_PREEMPT + printk("PREEMPT "); +#endif +#ifdef CONFIG_FRAME_POINTER + printk("FRAME_POINTER "); +#endif + if (current_cpu_data.features & AVR32_FEATURE_OCD) { + unsigned long did = __mfdr(DBGREG_DID); + printk("chip: 0x%03lx:0x%04lx rev %lu\n", + (did >> 1) & 0x7ff, + (did >> 12) & 0x7fff, + (did >> 28) & 0xf); + } else { + printk("cpu: arch %u r%u / core %u r%u\n", + current_cpu_data.arch_type, + current_cpu_data.arch_revision, + current_cpu_data.cpu_type, + current_cpu_data.cpu_revision); } + print_modules(); + show_regs_log_lvl(regs, KERN_EMERG); + show_stack_log_lvl(current, regs->sp, regs, KERN_EMERG); bust_spinlocks(0); spin_unlock_irq(&die_lock); - do_exit(SIGSEGV); + + if (in_interrupt()) + panic("Fatal exception in interrupt"); + + if (panic_on_oops) + panic("Fatal exception"); + + do_exit(err); } -void __die_if_kernel(const char *str, struct pt_regs *regs, unsigned long err, - const char *file, const char *func, unsigned long line) +void _exception(long signr, struct pt_regs *regs, int code, + unsigned long addr) { + siginfo_t info; + if (!user_mode(regs)) - __die(str, regs, err, file, func, line); -} + die("Unhandled exception in kernel mode", regs, signr); + + memset(&info, 0, sizeof(info)); + info.si_signo = signr; + info.si_code = code; + info.si_addr = (void __user *)addr; + force_sig_info(signr, &info, current); -asmlinkage void do_nmi(unsigned long ecr, struct pt_regs *regs) -{ -#ifdef CONFIG_SUBARCH_AVR32B /* - * The exception entry always saves RSR_EX. For NMI, this is - * wrong; it should be RSR_NMI + * Init gets no signals that it doesn't have a handler for. + * That's all very well, but if it has caused a synchronous + * exception and we ignore the resulting signal, it will just + * generate the same exception over and over again and we get + * nowhere. Better to kill it and let the kernel panic. */ - regs->sr = sysreg_read(RSR_NMI); -#endif + if (is_init(current)) { + __sighandler_t handler; + + spin_lock_irq(¤t->sighand->siglock); + handler = current->sighand->action[signr-1].sa.sa_handler; + spin_unlock_irq(¤t->sighand->siglock); + if (handler == SIG_DFL) { + /* init has generated a synchronous exception + and it doesn't have a handler for the signal */ + printk(KERN_CRIT "init has generated signal %ld " + "but has no handler for it\n", signr); + do_exit(signr); + } + } +} - printk("NMI taken!!!!\n"); - die("NMI", regs, ecr); - BUG(); +asmlinkage void do_nmi(unsigned long ecr, struct pt_regs *regs) +{ + printk(KERN_ALERT "Got Non-Maskable Interrupt, dumping regs\n"); + show_regs_log_lvl(regs, KERN_ALERT); + show_stack_log_lvl(current, regs->sp, regs, KERN_ALERT); } asmlinkage void do_critical_exception(unsigned long ecr, struct pt_regs *regs) { - printk("Unable to handle critical exception %lu at pc = %08lx!\n", - ecr, regs->pc); - die("Oops", regs, ecr); - BUG(); + die("Critical exception", regs, SIGKILL); } asmlinkage void do_address_exception(unsigned long ecr, struct pt_regs *regs) { - siginfo_t info; - - die_if_kernel("Oops: Address exception in kernel mode", regs, ecr); - -#ifdef DEBUG - if (ecr == ECR_ADDR_ALIGN_X) - pr_debug("Instruction Address Exception at pc = %08lx\n", - regs->pc); - else if (ecr == ECR_ADDR_ALIGN_R) - pr_debug("Data Address Exception (Read) at pc = %08lx\n", - regs->pc); - else if (ecr == ECR_ADDR_ALIGN_W) - pr_debug("Data Address Exception (Write) at pc = %08lx\n", - regs->pc); - else - BUG(); - - show_regs(regs); -#endif - - info.si_signo = SIGBUS; - info.si_errno = 0; - info.si_code = BUS_ADRALN; - info.si_addr = (void __user *)regs->pc; - - force_sig_info(SIGBUS, &info, current); + _exception(SIGBUS, regs, BUS_ADRALN, regs->pc); } /* This way of handling undefined instructions is stolen from ARM */ @@ -280,7 +157,8 @@ static int do_cop_absent(u32 insn) { int cop_nr; u32 cpucr; - if ( (insn & 0xfdf00000) == 0xf1900000 ) + + if ((insn & 0xfdf00000) == 0xf1900000) /* LDC0 */ cop_nr = 0; else @@ -292,136 +170,91 @@ static int do_cop_absent(u32 insn) sysreg_write(CPUCR, cpucr); cpucr = sysreg_read(CPUCR); - if ( !(cpucr & (1 << (24 + cop_nr))) ){ - printk("Coprocessor #%i not found!\n", cop_nr); - return -1; - } + if (!(cpucr & (1 << (24 + cop_nr)))) + return -ENODEV; return 0; } -#ifdef CONFIG_BUG -#ifdef CONFIG_DEBUG_BUGVERBOSE -static inline void do_bug_verbose(struct pt_regs *regs, u32 insn) -{ - char *file; - u16 line; - char c; - - if (__get_user(line, (u16 __user *)(regs->pc + 2))) - return; - if (__get_user(file, (char * __user *)(regs->pc + 4)) - || (unsigned long)file < PAGE_OFFSET - || __get_user(c, file)) - file = ""; - - printk(KERN_ALERT "kernel BUG at %s:%d!\n", file, line); -} -#else -static inline void do_bug_verbose(struct pt_regs *regs, u32 insn) +int is_valid_bugaddr(unsigned long pc) { + unsigned short opcode; + + if (pc < PAGE_OFFSET) + return 0; + if (probe_kernel_address((u16 *)pc, opcode)) + return 0; + return opcode == AVR32_BUG_OPCODE; } -#endif -#endif asmlinkage void do_illegal_opcode(unsigned long ecr, struct pt_regs *regs) { u32 insn; struct undef_hook *hook; - siginfo_t info; void __user *pc; + long code; - if (!user_mode(regs)) - goto kernel_trap; + if (!user_mode(regs) && (ecr == ECR_ILLEGAL_OPCODE)) { + enum bug_trap_type type; + + type = report_bug(regs->pc); + switch (type) { + case BUG_TRAP_TYPE_NONE: + break; + case BUG_TRAP_TYPE_WARN: + regs->pc += 2; + return; + case BUG_TRAP_TYPE_BUG: + die("Kernel BUG", regs, SIGKILL); + } + } local_irq_enable(); - pc = (void __user *)instruction_pointer(regs); - if (__get_user(insn, (u32 __user *)pc)) - goto invalid_area; + if (user_mode(regs)) { + pc = (void __user *)instruction_pointer(regs); + if (get_user(insn, (u32 __user *)pc)) + goto invalid_area; - if (ecr == ECR_COPROC_ABSENT) { - if (do_cop_absent(insn) == 0) + if (ecr == ECR_COPROC_ABSENT && !do_cop_absent(insn)) return; - } - spin_lock_irq(&undef_lock); - list_for_each_entry(hook, &undef_hook, node) { - if ((insn & hook->insn_mask) == hook->insn_val) { - if (hook->fn(regs, insn) == 0) { - spin_unlock_irq(&undef_lock); - return; + spin_lock_irq(&undef_lock); + list_for_each_entry(hook, &undef_hook, node) { + if ((insn & hook->insn_mask) == hook->insn_val) { + if (hook->fn(regs, insn) == 0) { + spin_unlock_irq(&undef_lock); + return; + } } } + spin_unlock_irq(&undef_lock); } - spin_unlock_irq(&undef_lock); - -invalid_area: -#ifdef DEBUG - printk("Illegal instruction at pc = %08lx\n", regs->pc); - if (regs->pc < TASK_SIZE) { - unsigned long ptbr, pgd, pte, *p; - - ptbr = sysreg_read(PTBR); - p = (unsigned long *)ptbr; - pgd = p[regs->pc >> 22]; - p = (unsigned long *)((pgd & 0x1ffff000) | 0x80000000); - pte = p[(regs->pc >> 12) & 0x3ff]; - printk("page table: 0x%08lx -> 0x%08lx -> 0x%08lx\n", ptbr, pgd, pte); - } -#endif - - info.si_signo = SIGILL; - info.si_errno = 0; - info.si_addr = (void __user *)regs->pc; switch (ecr) { - case ECR_ILLEGAL_OPCODE: - case ECR_UNIMPL_INSTRUCTION: - info.si_code = ILL_ILLOPC; - break; case ECR_PRIVILEGE_VIOLATION: - info.si_code = ILL_PRVOPC; + code = ILL_PRVOPC; break; case ECR_COPROC_ABSENT: - info.si_code = ILL_COPROC; + code = ILL_COPROC; break; default: - BUG(); + code = ILL_ILLOPC; + break; } - force_sig_info(SIGILL, &info, current); + _exception(SIGILL, regs, code, regs->pc); return; -kernel_trap: -#ifdef CONFIG_BUG - if (__kernel_text_address(instruction_pointer(regs))) { - insn = *(u16 *)instruction_pointer(regs); - if (insn == AVR32_BUG_OPCODE) { - do_bug_verbose(regs, insn); - die("Kernel BUG", regs, 0); - return; - } - } -#endif - - die("Oops: Illegal instruction in kernel code", regs, ecr); +invalid_area: + _exception(SIGSEGV, regs, SEGV_MAPERR, regs->pc); } asmlinkage void do_fpe(unsigned long ecr, struct pt_regs *regs) { - siginfo_t info; - - printk("Floating-point exception at pc = %08lx\n", regs->pc); - - /* We have no FPU... */ - info.si_signo = SIGILL; - info.si_errno = 0; - info.si_addr = (void __user *)regs->pc; - info.si_code = ILL_COPROC; - - force_sig_info(SIGILL, &info, current); + /* We have no FPU yet */ + _exception(SIGILL, regs, ILL_COPROC, regs->pc); 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