diff options
Diffstat (limited to 'ANDROID_3.4.5/arch/x86/kernel/traps.c')
| -rw-r--r-- | ANDROID_3.4.5/arch/x86/kernel/traps.c | 733 |
1 files changed, 733 insertions, 0 deletions
diff --git a/ANDROID_3.4.5/arch/x86/kernel/traps.c b/ANDROID_3.4.5/arch/x86/kernel/traps.c new file mode 100644 index 00000000..ff9281f1 --- /dev/null +++ b/ANDROID_3.4.5/arch/x86/kernel/traps.c @@ -0,0 +1,733 @@ +/* + * Copyright (C) 1991, 1992 Linus Torvalds + * Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs + * + * Pentium III FXSR, SSE support + * Gareth Hughes <gareth@valinux.com>, May 2000 + */ + +/* + * Handle hardware traps and faults. + */ +#include <linux/interrupt.h> +#include <linux/kallsyms.h> +#include <linux/spinlock.h> +#include <linux/kprobes.h> +#include <linux/uaccess.h> +#include <linux/kdebug.h> +#include <linux/kgdb.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/ptrace.h> +#include <linux/string.h> +#include <linux/delay.h> +#include <linux/errno.h> +#include <linux/kexec.h> +#include <linux/sched.h> +#include <linux/timer.h> +#include <linux/init.h> +#include <linux/bug.h> +#include <linux/nmi.h> +#include <linux/mm.h> +#include <linux/smp.h> +#include <linux/io.h> + +#ifdef CONFIG_EISA +#include <linux/ioport.h> +#include <linux/eisa.h> +#endif + +#ifdef CONFIG_MCA +#include <linux/mca.h> +#endif + +#if defined(CONFIG_EDAC) +#include <linux/edac.h> +#endif + +#include <asm/kmemcheck.h> +#include <asm/stacktrace.h> +#include <asm/processor.h> +#include <asm/debugreg.h> +#include <linux/atomic.h> +#include <asm/traps.h> +#include <asm/desc.h> +#include <asm/i387.h> +#include <asm/fpu-internal.h> +#include <asm/mce.h> + +#include <asm/mach_traps.h> + +#ifdef CONFIG_X86_64 +#include <asm/x86_init.h> +#include <asm/pgalloc.h> +#include <asm/proto.h> +#else +#include <asm/processor-flags.h> +#include <asm/setup.h> + +asmlinkage int system_call(void); + +/* Do we ignore FPU interrupts ? */ +char ignore_fpu_irq; + +/* + * The IDT has to be page-aligned to simplify the Pentium + * F0 0F bug workaround. + */ +gate_desc idt_table[NR_VECTORS] __page_aligned_data = { { { { 0, 0 } } }, }; +#endif + +DECLARE_BITMAP(used_vectors, NR_VECTORS); +EXPORT_SYMBOL_GPL(used_vectors); + +static inline void conditional_sti(struct pt_regs *regs) +{ + if (regs->flags & X86_EFLAGS_IF) + local_irq_enable(); +} + +static inline void preempt_conditional_sti(struct pt_regs *regs) +{ + inc_preempt_count(); + if (regs->flags & X86_EFLAGS_IF) + local_irq_enable(); +} + +static inline void conditional_cli(struct pt_regs *regs) +{ + if (regs->flags & X86_EFLAGS_IF) + local_irq_disable(); +} + +static inline void preempt_conditional_cli(struct pt_regs *regs) +{ + if (regs->flags & X86_EFLAGS_IF) + local_irq_disable(); + dec_preempt_count(); +} + +static void __kprobes +do_trap(int trapnr, int signr, char *str, struct pt_regs *regs, + long error_code, siginfo_t *info) +{ + struct task_struct *tsk = current; + +#ifdef CONFIG_X86_32 + if (regs->flags & X86_VM_MASK) { + /* + * traps 0, 1, 3, 4, and 5 should be forwarded to vm86. + * On nmi (interrupt 2), do_trap should not be called. + */ + if (trapnr < X86_TRAP_UD) + goto vm86_trap; + goto trap_signal; + } +#endif + + if (!user_mode(regs)) + goto kernel_trap; + +#ifdef CONFIG_X86_32 +trap_signal: +#endif + /* + * We want error_code and trap_nr set for userspace faults and + * kernelspace faults which result in die(), but not + * kernelspace faults which are fixed up. die() gives the + * process no chance to handle the signal and notice the + * kernel fault information, so that won't result in polluting + * the information about previously queued, but not yet + * delivered, faults. See also do_general_protection below. + */ + tsk->thread.error_code = error_code; + tsk->thread.trap_nr = trapnr; + +#ifdef CONFIG_X86_64 + if (show_unhandled_signals && unhandled_signal(tsk, signr) && + printk_ratelimit()) { + printk(KERN_INFO + "%s[%d] trap %s ip:%lx sp:%lx error:%lx", + tsk->comm, tsk->pid, str, + regs->ip, regs->sp, error_code); + print_vma_addr(" in ", regs->ip); + printk("\n"); + } +#endif + + if (info) + force_sig_info(signr, info, tsk); + else + force_sig(signr, tsk); + return; + +kernel_trap: + if (!fixup_exception(regs)) { + tsk->thread.error_code = error_code; + tsk->thread.trap_nr = trapnr; + die(str, regs, error_code); + } + return; + +#ifdef CONFIG_X86_32 +vm86_trap: + if (handle_vm86_trap((struct kernel_vm86_regs *) regs, + error_code, trapnr)) + goto trap_signal; + return; +#endif +} + +#define DO_ERROR(trapnr, signr, str, name) \ +dotraplinkage void do_##name(struct pt_regs *regs, long error_code) \ +{ \ + if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \ + == NOTIFY_STOP) \ + return; \ + conditional_sti(regs); \ + do_trap(trapnr, signr, str, regs, error_code, NULL); \ +} + +#define DO_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \ +dotraplinkage void do_##name(struct pt_regs *regs, long error_code) \ +{ \ + siginfo_t info; \ + info.si_signo = signr; \ + info.si_errno = 0; \ + info.si_code = sicode; \ + info.si_addr = (void __user *)siaddr; \ + if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \ + == NOTIFY_STOP) \ + return; \ + conditional_sti(regs); \ + do_trap(trapnr, signr, str, regs, error_code, &info); \ +} + +DO_ERROR_INFO(X86_TRAP_DE, SIGFPE, "divide error", divide_error, FPE_INTDIV, + regs->ip) +DO_ERROR(X86_TRAP_OF, SIGSEGV, "overflow", overflow) +DO_ERROR(X86_TRAP_BR, SIGSEGV, "bounds", bounds) +DO_ERROR_INFO(X86_TRAP_UD, SIGILL, "invalid opcode", invalid_op, ILL_ILLOPN, + regs->ip) +DO_ERROR(X86_TRAP_OLD_MF, SIGFPE, "coprocessor segment overrun", + coprocessor_segment_overrun) +DO_ERROR(X86_TRAP_TS, SIGSEGV, "invalid TSS", invalid_TSS) +DO_ERROR(X86_TRAP_NP, SIGBUS, "segment not present", segment_not_present) +#ifdef CONFIG_X86_32 +DO_ERROR(X86_TRAP_SS, SIGBUS, "stack segment", stack_segment) +#endif +DO_ERROR_INFO(X86_TRAP_AC, SIGBUS, "alignment check", alignment_check, + BUS_ADRALN, 0) + +#ifdef CONFIG_X86_64 +/* Runs on IST stack */ +dotraplinkage void do_stack_segment(struct pt_regs *regs, long error_code) +{ + if (notify_die(DIE_TRAP, "stack segment", regs, error_code, + X86_TRAP_SS, SIGBUS) == NOTIFY_STOP) + return; + preempt_conditional_sti(regs); + do_trap(X86_TRAP_SS, SIGBUS, "stack segment", regs, error_code, NULL); + preempt_conditional_cli(regs); +} + +dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code) +{ + static const char str[] = "double fault"; + struct task_struct *tsk = current; + + /* Return not checked because double check cannot be ignored */ + notify_die(DIE_TRAP, str, regs, error_code, X86_TRAP_DF, SIGSEGV); + + tsk->thread.error_code = error_code; + tsk->thread.trap_nr = X86_TRAP_DF; + + /* + * This is always a kernel trap and never fixable (and thus must + * never return). + */ + for (;;) + die(str, regs, error_code); +} +#endif + +dotraplinkage void __kprobes +do_general_protection(struct pt_regs *regs, long error_code) +{ + struct task_struct *tsk; + + conditional_sti(regs); + +#ifdef CONFIG_X86_32 + if (regs->flags & X86_VM_MASK) + goto gp_in_vm86; +#endif + + tsk = current; + if (!user_mode(regs)) + goto gp_in_kernel; + + tsk->thread.error_code = error_code; + tsk->thread.trap_nr = X86_TRAP_GP; + + if (show_unhandled_signals && unhandled_signal(tsk, SIGSEGV) && + printk_ratelimit()) { + printk(KERN_INFO + "%s[%d] general protection ip:%lx sp:%lx error:%lx", + tsk->comm, task_pid_nr(tsk), + regs->ip, regs->sp, error_code); + print_vma_addr(" in ", regs->ip); + printk("\n"); + } + + force_sig(SIGSEGV, tsk); + return; + +#ifdef CONFIG_X86_32 +gp_in_vm86: + local_irq_enable(); + handle_vm86_fault((struct kernel_vm86_regs *) regs, error_code); + return; +#endif + +gp_in_kernel: + if (fixup_exception(regs)) + return; + + tsk->thread.error_code = error_code; + tsk->thread.trap_nr = X86_TRAP_GP; + if (notify_die(DIE_GPF, "general protection fault", regs, error_code, + X86_TRAP_GP, SIGSEGV) == NOTIFY_STOP) + return; + die("general protection fault", regs, error_code); +} + +/* May run on IST stack. */ +dotraplinkage void __kprobes do_int3(struct pt_regs *regs, long error_code) +{ +#ifdef CONFIG_KGDB_LOW_LEVEL_TRAP + if (kgdb_ll_trap(DIE_INT3, "int3", regs, error_code, X86_TRAP_BP, + SIGTRAP) == NOTIFY_STOP) + return; +#endif /* CONFIG_KGDB_LOW_LEVEL_TRAP */ + + if (notify_die(DIE_INT3, "int3", regs, error_code, X86_TRAP_BP, + SIGTRAP) == NOTIFY_STOP) + return; + + /* + * Let others (NMI) know that the debug stack is in use + * as we may switch to the interrupt stack. + */ + debug_stack_usage_inc(); + preempt_conditional_sti(regs); + do_trap(X86_TRAP_BP, SIGTRAP, "int3", regs, error_code, NULL); + preempt_conditional_cli(regs); + debug_stack_usage_dec(); +} + +#ifdef CONFIG_X86_64 +/* + * Help handler running on IST stack to switch back to user stack + * for scheduling or signal handling. The actual stack switch is done in + * entry.S + */ +asmlinkage __kprobes struct pt_regs *sync_regs(struct pt_regs *eregs) +{ + struct pt_regs *regs = eregs; + /* Did already sync */ + if (eregs == (struct pt_regs *)eregs->sp) + ; + /* Exception from user space */ + else if (user_mode(eregs)) + regs = task_pt_regs(current); + /* + * Exception from kernel and interrupts are enabled. Move to + * kernel process stack. + */ + else if (eregs->flags & X86_EFLAGS_IF) + regs = (struct pt_regs *)(eregs->sp -= sizeof(struct pt_regs)); + if (eregs != regs) + *regs = *eregs; + return regs; +} +#endif + +/* + * Our handling of the processor debug registers is non-trivial. + * We do not clear them on entry and exit from the kernel. Therefore + * it is possible to get a watchpoint trap here from inside the kernel. + * However, the code in ./ptrace.c has ensured that the user can + * only set watchpoints on userspace addresses. Therefore the in-kernel + * watchpoint trap can only occur in code which is reading/writing + * from user space. Such code must not hold kernel locks (since it + * can equally take a page fault), therefore it is safe to call + * force_sig_info even though that claims and releases locks. + * + * Code in ./signal.c ensures that the debug control register + * is restored before we deliver any signal, and therefore that + * user code runs with the correct debug control register even though + * we clear it here. + * + * Being careful here means that we don't have to be as careful in a + * lot of more complicated places (task switching can be a bit lazy + * about restoring all the debug state, and ptrace doesn't have to + * find every occurrence of the TF bit that could be saved away even + * by user code) + * + * May run on IST stack. + */ +dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code) +{ + struct task_struct *tsk = current; + int user_icebp = 0; + unsigned long dr6; + int si_code; + + get_debugreg(dr6, 6); + + /* Filter out all the reserved bits which are preset to 1 */ + dr6 &= ~DR6_RESERVED; + + /* + * If dr6 has no reason to give us about the origin of this trap, + * then it's very likely the result of an icebp/int01 trap. + * User wants a sigtrap for that. + */ + if (!dr6 && user_mode(regs)) + user_icebp = 1; + + /* Catch kmemcheck conditions first of all! */ + if ((dr6 & DR_STEP) && kmemcheck_trap(regs)) + return; + + /* DR6 may or may not be cleared by the CPU */ + set_debugreg(0, 6); + + /* + * The processor cleared BTF, so don't mark that we need it set. + */ + clear_tsk_thread_flag(tsk, TIF_BLOCKSTEP); + + /* Store the virtualized DR6 value */ + tsk->thread.debugreg6 = dr6; + + if (notify_die(DIE_DEBUG, "debug", regs, PTR_ERR(&dr6), error_code, + SIGTRAP) == NOTIFY_STOP) + return; + + /* + * Let others (NMI) know that the debug stack is in use + * as we may switch to the interrupt stack. + */ + debug_stack_usage_inc(); + + /* It's safe to allow irq's after DR6 has been saved */ + preempt_conditional_sti(regs); + + if (regs->flags & X86_VM_MASK) { + handle_vm86_trap((struct kernel_vm86_regs *) regs, error_code, + X86_TRAP_DB); + preempt_conditional_cli(regs); + debug_stack_usage_dec(); + return; + } + + /* + * Single-stepping through system calls: ignore any exceptions in + * kernel space, but re-enable TF when returning to user mode. + * + * We already checked v86 mode above, so we can check for kernel mode + * by just checking the CPL of CS. + */ + if ((dr6 & DR_STEP) && !user_mode(regs)) { + tsk->thread.debugreg6 &= ~DR_STEP; + set_tsk_thread_flag(tsk, TIF_SINGLESTEP); + regs->flags &= ~X86_EFLAGS_TF; + } + si_code = get_si_code(tsk->thread.debugreg6); + if (tsk->thread.debugreg6 & (DR_STEP | DR_TRAP_BITS) || user_icebp) + send_sigtrap(tsk, regs, error_code, si_code); + preempt_conditional_cli(regs); + debug_stack_usage_dec(); + + return; +} + +/* + * Note that we play around with the 'TS' bit in an attempt to get + * the correct behaviour even in the presence of the asynchronous + * IRQ13 behaviour + */ +void math_error(struct pt_regs *regs, int error_code, int trapnr) +{ + struct task_struct *task = current; + siginfo_t info; + unsigned short err; + char *str = (trapnr == X86_TRAP_MF) ? "fpu exception" : + "simd exception"; + + if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, SIGFPE) == NOTIFY_STOP) + return; + conditional_sti(regs); + + if (!user_mode_vm(regs)) + { + if (!fixup_exception(regs)) { + task->thread.error_code = error_code; + task->thread.trap_nr = trapnr; + die(str, regs, error_code); + } + return; + } + + /* + * Save the info for the exception handler and clear the error. + */ + save_init_fpu(task); + task->thread.trap_nr = trapnr; + task->thread.error_code = error_code; + info.si_signo = SIGFPE; + info.si_errno = 0; + info.si_addr = (void __user *)regs->ip; + if (trapnr == X86_TRAP_MF) { + unsigned short cwd, swd; + /* + * (~cwd & swd) will mask out exceptions that are not set to unmasked + * status. 0x3f is the exception bits in these regs, 0x200 is the + * C1 reg you need in case of a stack fault, 0x040 is the stack + * fault bit. We should only be taking one exception at a time, + * so if this combination doesn't produce any single exception, + * then we have a bad program that isn't synchronizing its FPU usage + * and it will suffer the consequences since we won't be able to + * fully reproduce the context of the exception + */ + cwd = get_fpu_cwd(task); + swd = get_fpu_swd(task); + + err = swd & ~cwd; + } else { + /* + * The SIMD FPU exceptions are handled a little differently, as there + * is only a single status/control register. Thus, to determine which + * unmasked exception was caught we must mask the exception mask bits + * at 0x1f80, and then use these to mask the exception bits at 0x3f. + */ + unsigned short mxcsr = get_fpu_mxcsr(task); + err = ~(mxcsr >> 7) & mxcsr; + } + + if (err & 0x001) { /* Invalid op */ + /* + * swd & 0x240 == 0x040: Stack Underflow + * swd & 0x240 == 0x240: Stack Overflow + * User must clear the SF bit (0x40) if set + */ + info.si_code = FPE_FLTINV; + } else if (err & 0x004) { /* Divide by Zero */ + info.si_code = FPE_FLTDIV; + } else if (err & 0x008) { /* Overflow */ + info.si_code = FPE_FLTOVF; + } else if (err & 0x012) { /* Denormal, Underflow */ + info.si_code = FPE_FLTUND; + } else if (err & 0x020) { /* Precision */ + info.si_code = FPE_FLTRES; + } else { + /* + * If we're using IRQ 13, or supposedly even some trap + * X86_TRAP_MF implementations, it's possible + * we get a spurious trap, which is not an error. + */ + return; + } + force_sig_info(SIGFPE, &info, task); +} + +dotraplinkage void do_coprocessor_error(struct pt_regs *regs, long error_code) +{ +#ifdef CONFIG_X86_32 + ignore_fpu_irq = 1; +#endif + + math_error(regs, error_code, X86_TRAP_MF); +} + +dotraplinkage void +do_simd_coprocessor_error(struct pt_regs *regs, long error_code) +{ + math_error(regs, error_code, X86_TRAP_XF); +} + +dotraplinkage void +do_spurious_interrupt_bug(struct pt_regs *regs, long error_code) +{ + conditional_sti(regs); +#if 0 + /* No need to warn about this any longer. */ + printk(KERN_INFO "Ignoring P6 Local APIC Spurious Interrupt Bug...\n"); +#endif +} + +asmlinkage void __attribute__((weak)) smp_thermal_interrupt(void) +{ +} + +asmlinkage void __attribute__((weak)) smp_threshold_interrupt(void) +{ +} + +/* + * 'math_state_restore()' saves the current math information in the + * old math state array, and gets the new ones from the current task + * + * Careful.. There are problems with IBM-designed IRQ13 behaviour. + * Don't touch unless you *really* know how it works. + * + * Must be called with kernel preemption disabled (eg with local + * local interrupts as in the case of do_device_not_available). + */ +void math_state_restore(void) +{ + struct task_struct *tsk = current; + + if (!tsk_used_math(tsk)) { + local_irq_enable(); + /* + * does a slab alloc which can sleep + */ + if (init_fpu(tsk)) { + /* + * ran out of memory! + */ + do_group_exit(SIGKILL); + return; + } + local_irq_disable(); + } + + __thread_fpu_begin(tsk); + /* + * Paranoid restore. send a SIGSEGV if we fail to restore the state. + */ + if (unlikely(restore_fpu_checking(tsk))) { + __thread_fpu_end(tsk); + force_sig(SIGSEGV, tsk); + return; + } + + tsk->fpu_counter++; +} +EXPORT_SYMBOL_GPL(math_state_restore); + +dotraplinkage void __kprobes +do_device_not_available(struct pt_regs *regs, long error_code) +{ +#ifdef CONFIG_MATH_EMULATION + if (read_cr0() & X86_CR0_EM) { + struct math_emu_info info = { }; + + conditional_sti(regs); + + info.regs = regs; + math_emulate(&info); + return; + } +#endif + math_state_restore(); /* interrupts still off */ +#ifdef CONFIG_X86_32 + conditional_sti(regs); +#endif +} + +#ifdef CONFIG_X86_32 +dotraplinkage void do_iret_error(struct pt_regs *regs, long error_code) +{ + siginfo_t info; + local_irq_enable(); + + info.si_signo = SIGILL; + info.si_errno = 0; + info.si_code = ILL_BADSTK; + info.si_addr = NULL; + if (notify_die(DIE_TRAP, "iret exception", regs, error_code, + X86_TRAP_IRET, SIGILL) == NOTIFY_STOP) + return; + do_trap(X86_TRAP_IRET, SIGILL, "iret exception", regs, error_code, + &info); +} +#endif + +/* Set of traps needed for early debugging. */ +void __init early_trap_init(void) +{ + set_intr_gate_ist(X86_TRAP_DB, &debug, DEBUG_STACK); + /* int3 can be called from all */ + set_system_intr_gate_ist(X86_TRAP_BP, &int3, DEBUG_STACK); + set_intr_gate(X86_TRAP_PF, &page_fault); + load_idt(&idt_descr); +} + +void __init trap_init(void) +{ + int i; + +#ifdef CONFIG_EISA + void __iomem *p = early_ioremap(0x0FFFD9, 4); + + if (readl(p) == 'E' + ('I'<<8) + ('S'<<16) + ('A'<<24)) + EISA_bus = 1; + early_iounmap(p, 4); +#endif + + set_intr_gate(X86_TRAP_DE, ÷_error); + set_intr_gate_ist(X86_TRAP_NMI, &nmi, NMI_STACK); + /* int4 can be called from all */ + set_system_intr_gate(X86_TRAP_OF, &overflow); + set_intr_gate(X86_TRAP_BR, &bounds); + set_intr_gate(X86_TRAP_UD, &invalid_op); + set_intr_gate(X86_TRAP_NM, &device_not_available); +#ifdef CONFIG_X86_32 + set_task_gate(X86_TRAP_DF, GDT_ENTRY_DOUBLEFAULT_TSS); +#else + set_intr_gate_ist(X86_TRAP_DF, &double_fault, DOUBLEFAULT_STACK); +#endif + set_intr_gate(X86_TRAP_OLD_MF, &coprocessor_segment_overrun); + set_intr_gate(X86_TRAP_TS, &invalid_TSS); + set_intr_gate(X86_TRAP_NP, &segment_not_present); + set_intr_gate_ist(X86_TRAP_SS, &stack_segment, STACKFAULT_STACK); + set_intr_gate(X86_TRAP_GP, &general_protection); + set_intr_gate(X86_TRAP_SPURIOUS, &spurious_interrupt_bug); + set_intr_gate(X86_TRAP_MF, &coprocessor_error); + set_intr_gate(X86_TRAP_AC, &alignment_check); +#ifdef CONFIG_X86_MCE + set_intr_gate_ist(X86_TRAP_MC, &machine_check, MCE_STACK); +#endif + set_intr_gate(X86_TRAP_XF, &simd_coprocessor_error); + + /* Reserve all the builtin and the syscall vector: */ + for (i = 0; i < FIRST_EXTERNAL_VECTOR; i++) + set_bit(i, used_vectors); + +#ifdef CONFIG_IA32_EMULATION + set_system_intr_gate(IA32_SYSCALL_VECTOR, ia32_syscall); + set_bit(IA32_SYSCALL_VECTOR, used_vectors); +#endif + +#ifdef CONFIG_X86_32 + set_system_trap_gate(SYSCALL_VECTOR, &system_call); + set_bit(SYSCALL_VECTOR, used_vectors); +#endif + + /* + * Should be a barrier for any external CPU state: + */ + cpu_init(); + + x86_init.irqs.trap_init(); + +#ifdef CONFIG_X86_64 + memcpy(&nmi_idt_table, &idt_table, IDT_ENTRIES * 16); + set_nmi_gate(X86_TRAP_DB, &debug); + set_nmi_gate(X86_TRAP_BP, &int3); +#endif +} |