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Diffstat (limited to 'arch/x86_64/kernel/traps.c')
-rw-r--r--arch/x86_64/kernel/traps.c948
1 files changed, 948 insertions, 0 deletions
diff --git a/arch/x86_64/kernel/traps.c b/arch/x86_64/kernel/traps.c
new file mode 100644
index 000000000000..d87ac6496cc2
--- /dev/null
+++ b/arch/x86_64/kernel/traps.c
@@ -0,0 +1,948 @@
+/*
+ * linux/arch/x86-64/traps.c
+ *
+ * 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
+ *
+ * $Id: traps.c,v 1.36 2002/03/24 11:09:10 ak Exp $
+ */
+
+/*
+ * 'Traps.c' handles hardware traps and faults after we have saved some
+ * state in 'entry.S'.
+ */
+#include <linux/config.h>
+#include <linux/sched.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/init.h>
+#include <linux/delay.h>
+#include <linux/spinlock.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+
+#include <asm/system.h>
+#include <asm/uaccess.h>
+#include <asm/io.h>
+#include <asm/atomic.h>
+#include <asm/debugreg.h>
+#include <asm/desc.h>
+#include <asm/i387.h>
+#include <asm/kdebug.h>
+#include <asm/processor.h>
+
+#include <asm/smp.h>
+#include <asm/pgalloc.h>
+#include <asm/pda.h>
+#include <asm/proto.h>
+#include <asm/nmi.h>
+
+#include <linux/irq.h>
+
+
+extern struct gate_struct idt_table[256];
+
+asmlinkage void divide_error(void);
+asmlinkage void debug(void);
+asmlinkage void nmi(void);
+asmlinkage void int3(void);
+asmlinkage void overflow(void);
+asmlinkage void bounds(void);
+asmlinkage void invalid_op(void);
+asmlinkage void device_not_available(void);
+asmlinkage void double_fault(void);
+asmlinkage void coprocessor_segment_overrun(void);
+asmlinkage void invalid_TSS(void);
+asmlinkage void segment_not_present(void);
+asmlinkage void stack_segment(void);
+asmlinkage void general_protection(void);
+asmlinkage void page_fault(void);
+asmlinkage void coprocessor_error(void);
+asmlinkage void simd_coprocessor_error(void);
+asmlinkage void reserved(void);
+asmlinkage void alignment_check(void);
+asmlinkage void machine_check(void);
+asmlinkage void spurious_interrupt_bug(void);
+asmlinkage void call_debug(void);
+
+struct notifier_block *die_chain;
+static DEFINE_SPINLOCK(die_notifier_lock);
+
+int register_die_notifier(struct notifier_block *nb)
+{
+ int err = 0;
+ unsigned long flags;
+ spin_lock_irqsave(&die_notifier_lock, flags);
+ err = notifier_chain_register(&die_chain, nb);
+ spin_unlock_irqrestore(&die_notifier_lock, flags);
+ return err;
+}
+
+static inline void conditional_sti(struct pt_regs *regs)
+{
+ if (regs->eflags & X86_EFLAGS_IF)
+ local_irq_enable();
+}
+
+static int kstack_depth_to_print = 10;
+
+#ifdef CONFIG_KALLSYMS
+#include <linux/kallsyms.h>
+int printk_address(unsigned long address)
+{
+ unsigned long offset = 0, symsize;
+ const char *symname;
+ char *modname;
+ char *delim = ":";
+ char namebuf[128];
+
+ symname = kallsyms_lookup(address, &symsize, &offset, &modname, namebuf);
+ if (!symname)
+ return printk("[<%016lx>]", address);
+ if (!modname)
+ modname = delim = "";
+ return printk("<%016lx>{%s%s%s%s%+ld}",
+ address,delim,modname,delim,symname,offset);
+}
+#else
+int printk_address(unsigned long address)
+{
+ return printk("[<%016lx>]", address);
+}
+#endif
+
+unsigned long *in_exception_stack(int cpu, unsigned long stack)
+{
+ int k;
+ for (k = 0; k < N_EXCEPTION_STACKS; k++) {
+ struct tss_struct *tss = &per_cpu(init_tss, cpu);
+ unsigned long start = tss->ist[k] - EXCEPTION_STKSZ;
+
+ if (stack >= start && stack < tss->ist[k])
+ return (unsigned long *)tss->ist[k];
+ }
+ return NULL;
+}
+
+/*
+ * x86-64 can have upto three kernel stacks:
+ * process stack
+ * interrupt stack
+ * severe exception (double fault, nmi, stack fault) hardware stack
+ * Check and process them in order.
+ */
+
+void show_trace(unsigned long *stack)
+{
+ unsigned long addr;
+ unsigned long *irqstack, *irqstack_end, *estack_end;
+ const int cpu = safe_smp_processor_id();
+ int i;
+
+ printk("\nCall Trace:");
+ i = 0;
+
+ estack_end = in_exception_stack(cpu, (unsigned long)stack);
+ if (estack_end) {
+ while (stack < estack_end) {
+ addr = *stack++;
+ if (__kernel_text_address(addr)) {
+ i += printk_address(addr);
+ i += printk(" ");
+ if (i > 50) {
+ printk("\n");
+ i = 0;
+ }
+ }
+ }
+ i += printk(" <EOE> ");
+ i += 7;
+ stack = (unsigned long *) estack_end[-2];
+ }
+
+ irqstack_end = (unsigned long *) (cpu_pda[cpu].irqstackptr);
+ irqstack = (unsigned long *) (cpu_pda[cpu].irqstackptr - IRQSTACKSIZE + 64);
+
+ if (stack >= irqstack && stack < irqstack_end) {
+ printk("<IRQ> ");
+ while (stack < irqstack_end) {
+ addr = *stack++;
+ /*
+ * If the address is either in the text segment of the
+ * kernel, or in the region which contains vmalloc'ed
+ * memory, it *may* be the address of a calling
+ * routine; if so, print it so that someone tracing
+ * down the cause of the crash will be able to figure
+ * out the call path that was taken.
+ */
+ if (__kernel_text_address(addr)) {
+ i += printk_address(addr);
+ i += printk(" ");
+ if (i > 50) {
+ printk("\n ");
+ i = 0;
+ }
+ }
+ }
+ stack = (unsigned long *) (irqstack_end[-1]);
+ printk(" <EOI> ");
+ i += 7;
+ }
+
+ while (((long) stack & (THREAD_SIZE-1)) != 0) {
+ addr = *stack++;
+ if (__kernel_text_address(addr)) {
+ i += printk_address(addr);
+ i += printk(" ");
+ if (i > 50) {
+ printk("\n ");
+ i = 0;
+ }
+ }
+ }
+ printk("\n");
+}
+
+void show_stack(struct task_struct *tsk, unsigned long * rsp)
+{
+ unsigned long *stack;
+ int i;
+ const int cpu = safe_smp_processor_id();
+ unsigned long *irqstack_end = (unsigned long *) (cpu_pda[cpu].irqstackptr);
+ unsigned long *irqstack = (unsigned long *) (cpu_pda[cpu].irqstackptr - IRQSTACKSIZE);
+
+ // debugging aid: "show_stack(NULL, NULL);" prints the
+ // back trace for this cpu.
+
+ if (rsp == NULL) {
+ if (tsk)
+ rsp = (unsigned long *)tsk->thread.rsp;
+ else
+ rsp = (unsigned long *)&rsp;
+ }
+
+ stack = rsp;
+ for(i=0; i < kstack_depth_to_print; i++) {
+ if (stack >= irqstack && stack <= irqstack_end) {
+ if (stack == irqstack_end) {
+ stack = (unsigned long *) (irqstack_end[-1]);
+ printk(" <EOI> ");
+ }
+ } else {
+ if (((long) stack & (THREAD_SIZE-1)) == 0)
+ break;
+ }
+ if (i && ((i % 4) == 0))
+ printk("\n ");
+ printk("%016lx ", *stack++);
+ }
+ show_trace((unsigned long *)rsp);
+}
+
+/*
+ * The architecture-independent dump_stack generator
+ */
+void dump_stack(void)
+{
+ unsigned long dummy;
+ show_trace(&dummy);
+}
+
+EXPORT_SYMBOL(dump_stack);
+
+void show_registers(struct pt_regs *regs)
+{
+ int i;
+ int in_kernel = (regs->cs & 3) == 0;
+ unsigned long rsp;
+ const int cpu = safe_smp_processor_id();
+ struct task_struct *cur = cpu_pda[cpu].pcurrent;
+
+ rsp = regs->rsp;
+
+ printk("CPU %d ", cpu);
+ __show_regs(regs);
+ printk("Process %s (pid: %d, threadinfo %p, task %p)\n",
+ cur->comm, cur->pid, cur->thread_info, cur);
+
+ /*
+ * When in-kernel, we also print out the stack and code at the
+ * time of the fault..
+ */
+ if (in_kernel) {
+
+ printk("Stack: ");
+ show_stack(NULL, (unsigned long*)rsp);
+
+ printk("\nCode: ");
+ if(regs->rip < PAGE_OFFSET)
+ goto bad;
+
+ for(i=0;i<20;i++)
+ {
+ unsigned char c;
+ if(__get_user(c, &((unsigned char*)regs->rip)[i])) {
+bad:
+ printk(" Bad RIP value.");
+ break;
+ }
+ printk("%02x ", c);
+ }
+ }
+ printk("\n");
+}
+
+void handle_BUG(struct pt_regs *regs)
+{
+ struct bug_frame f;
+ char tmp;
+
+ if (regs->cs & 3)
+ return;
+ if (__copy_from_user(&f, (struct bug_frame *) regs->rip,
+ sizeof(struct bug_frame)))
+ return;
+ if ((unsigned long)f.filename < __PAGE_OFFSET ||
+ f.ud2[0] != 0x0f || f.ud2[1] != 0x0b)
+ return;
+ if (__get_user(tmp, f.filename))
+ f.filename = "unmapped filename";
+ printk("----------- [cut here ] --------- [please bite here ] ---------\n");
+ printk(KERN_ALERT "Kernel BUG at %.50s:%d\n", f.filename, f.line);
+}
+
+void out_of_line_bug(void)
+{
+ BUG();
+}
+
+static DEFINE_SPINLOCK(die_lock);
+static int die_owner = -1;
+
+void oops_begin(void)
+{
+ int cpu = safe_smp_processor_id();
+ /* racy, but better than risking deadlock. */
+ local_irq_disable();
+ if (!spin_trylock(&die_lock)) {
+ if (cpu == die_owner)
+ /* nested oops. should stop eventually */;
+ else
+ spin_lock(&die_lock);
+ }
+ die_owner = cpu;
+ console_verbose();
+ bust_spinlocks(1);
+}
+
+void oops_end(void)
+{
+ die_owner = -1;
+ bust_spinlocks(0);
+ spin_unlock(&die_lock);
+ if (panic_on_oops)
+ panic("Oops");
+}
+
+void __die(const char * str, struct pt_regs * regs, long err)
+{
+ static int die_counter;
+ printk(KERN_EMERG "%s: %04lx [%u] ", str, err & 0xffff,++die_counter);
+#ifdef CONFIG_PREEMPT
+ printk("PREEMPT ");
+#endif
+#ifdef CONFIG_SMP
+ printk("SMP ");
+#endif
+#ifdef CONFIG_DEBUG_PAGEALLOC
+ printk("DEBUG_PAGEALLOC");
+#endif
+ printk("\n");
+ notify_die(DIE_OOPS, (char *)str, regs, err, 255, SIGSEGV);
+ show_registers(regs);
+ /* Executive summary in case the oops scrolled away */
+ printk(KERN_ALERT "RIP ");
+ printk_address(regs->rip);
+ printk(" RSP <%016lx>\n", regs->rsp);
+}
+
+void die(const char * str, struct pt_regs * regs, long err)
+{
+ oops_begin();
+ handle_BUG(regs);
+ __die(str, regs, err);
+ oops_end();
+ do_exit(SIGSEGV);
+}
+static inline void die_if_kernel(const char * str, struct pt_regs * regs, long err)
+{
+ if (!(regs->eflags & VM_MASK) && (regs->cs == __KERNEL_CS))
+ die(str, regs, err);
+}
+
+void die_nmi(char *str, struct pt_regs *regs)
+{
+ oops_begin();
+ /*
+ * We are in trouble anyway, lets at least try
+ * to get a message out.
+ */
+ printk(str, safe_smp_processor_id());
+ show_registers(regs);
+ if (panic_on_timeout || panic_on_oops)
+ panic("nmi watchdog");
+ printk("console shuts up ...\n");
+ oops_end();
+ do_exit(SIGSEGV);
+}
+
+static void do_trap(int trapnr, int signr, char *str,
+ struct pt_regs * regs, long error_code, siginfo_t *info)
+{
+ conditional_sti(regs);
+
+#ifdef CONFIG_CHECKING
+ {
+ unsigned long gs;
+ struct x8664_pda *pda = cpu_pda + safe_smp_processor_id();
+ rdmsrl(MSR_GS_BASE, gs);
+ if (gs != (unsigned long)pda) {
+ wrmsrl(MSR_GS_BASE, pda);
+ printk("%s: wrong gs %lx expected %p rip %lx\n", str, gs, pda,
+ regs->rip);
+ }
+ }
+#endif
+
+ if ((regs->cs & 3) != 0) {
+ struct task_struct *tsk = current;
+
+ if (exception_trace && unhandled_signal(tsk, signr))
+ printk(KERN_INFO
+ "%s[%d] trap %s rip:%lx rsp:%lx error:%lx\n",
+ tsk->comm, tsk->pid, str,
+ regs->rip,regs->rsp,error_code);
+
+ tsk->thread.error_code = error_code;
+ tsk->thread.trap_no = trapnr;
+ if (info)
+ force_sig_info(signr, info, tsk);
+ else
+ force_sig(signr, tsk);
+ return;
+ }
+
+
+ /* kernel trap */
+ {
+ const struct exception_table_entry *fixup;
+ fixup = search_exception_tables(regs->rip);
+ if (fixup) {
+ regs->rip = fixup->fixup;
+ } else
+ die(str, regs, error_code);
+ return;
+ }
+}
+
+#define DO_ERROR(trapnr, signr, str, name) \
+asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
+{ \
+ if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
+ == NOTIFY_STOP) \
+ return; \
+ do_trap(trapnr, signr, str, regs, error_code, NULL); \
+}
+
+#define DO_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \
+asmlinkage 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; \
+ do_trap(trapnr, signr, str, regs, error_code, &info); \
+}
+
+DO_ERROR_INFO( 0, SIGFPE, "divide error", divide_error, FPE_INTDIV, regs->rip)
+DO_ERROR( 4, SIGSEGV, "overflow", overflow)
+DO_ERROR( 5, SIGSEGV, "bounds", bounds)
+DO_ERROR_INFO( 6, SIGILL, "invalid operand", invalid_op, ILL_ILLOPN, regs->rip)
+DO_ERROR( 7, SIGSEGV, "device not available", device_not_available)
+DO_ERROR( 9, SIGFPE, "coprocessor segment overrun", coprocessor_segment_overrun)
+DO_ERROR(10, SIGSEGV, "invalid TSS", invalid_TSS)
+DO_ERROR(11, SIGBUS, "segment not present", segment_not_present)
+DO_ERROR_INFO(17, SIGBUS, "alignment check", alignment_check, BUS_ADRALN, 0)
+DO_ERROR(18, SIGSEGV, "reserved", reserved)
+
+#define DO_ERROR_STACK(trapnr, signr, str, name) \
+asmlinkage void *do_##name(struct pt_regs * regs, long error_code) \
+{ \
+ struct pt_regs *pr = ((struct pt_regs *)(current->thread.rsp0))-1; \
+ if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
+ == NOTIFY_STOP) \
+ return regs; \
+ if (regs->cs & 3) { \
+ memcpy(pr, regs, sizeof(struct pt_regs)); \
+ regs = pr; \
+ } \
+ do_trap(trapnr, signr, str, regs, error_code, NULL); \
+ return regs; \
+}
+
+DO_ERROR_STACK(12, SIGBUS, "stack segment", stack_segment)
+DO_ERROR_STACK( 8, SIGSEGV, "double fault", double_fault)
+
+asmlinkage void do_general_protection(struct pt_regs * regs, long error_code)
+{
+ conditional_sti(regs);
+
+#ifdef CONFIG_CHECKING
+ {
+ unsigned long gs;
+ struct x8664_pda *pda = cpu_pda + safe_smp_processor_id();
+ rdmsrl(MSR_GS_BASE, gs);
+ if (gs != (unsigned long)pda) {
+ wrmsrl(MSR_GS_BASE, pda);
+ oops_in_progress++;
+ printk("general protection handler: wrong gs %lx expected %p\n", gs, pda);
+ oops_in_progress--;
+ }
+ }
+#endif
+
+ if ((regs->cs & 3)!=0) {
+ struct task_struct *tsk = current;
+
+ if (exception_trace && unhandled_signal(tsk, SIGSEGV))
+ printk(KERN_INFO
+ "%s[%d] general protection rip:%lx rsp:%lx error:%lx\n",
+ tsk->comm, tsk->pid,
+ regs->rip,regs->rsp,error_code);
+
+ tsk->thread.error_code = error_code;
+ tsk->thread.trap_no = 13;
+ force_sig(SIGSEGV, tsk);
+ return;
+ }
+
+ /* kernel gp */
+ {
+ const struct exception_table_entry *fixup;
+ fixup = search_exception_tables(regs->rip);
+ if (fixup) {
+ regs->rip = fixup->fixup;
+ return;
+ }
+ if (notify_die(DIE_GPF, "general protection fault", regs,
+ error_code, 13, SIGSEGV) == NOTIFY_STOP)
+ return;
+ die("general protection fault", regs, error_code);
+ }
+}
+
+static void mem_parity_error(unsigned char reason, struct pt_regs * regs)
+{
+ printk("Uhhuh. NMI received. Dazed and confused, but trying to continue\n");
+ printk("You probably have a hardware problem with your RAM chips\n");
+
+ /* Clear and disable the memory parity error line. */
+ reason = (reason & 0xf) | 4;
+ outb(reason, 0x61);
+}
+
+static void io_check_error(unsigned char reason, struct pt_regs * regs)
+{
+ printk("NMI: IOCK error (debug interrupt?)\n");
+ show_registers(regs);
+
+ /* Re-enable the IOCK line, wait for a few seconds */
+ reason = (reason & 0xf) | 8;
+ outb(reason, 0x61);
+ mdelay(2000);
+ reason &= ~8;
+ outb(reason, 0x61);
+}
+
+static void unknown_nmi_error(unsigned char reason, struct pt_regs * regs)
+{ printk("Uhhuh. NMI received for unknown reason %02x.\n", reason);
+ printk("Dazed and confused, but trying to continue\n");
+ printk("Do you have a strange power saving mode enabled?\n");
+}
+
+asmlinkage void default_do_nmi(struct pt_regs *regs)
+{
+ unsigned char reason = 0;
+
+ /* Only the BSP gets external NMIs from the system. */
+ if (!smp_processor_id())
+ reason = get_nmi_reason();
+
+ if (!(reason & 0xc0)) {
+ if (notify_die(DIE_NMI_IPI, "nmi_ipi", regs, reason, 0, SIGINT)
+ == NOTIFY_STOP)
+ return;
+#ifdef CONFIG_X86_LOCAL_APIC
+ /*
+ * Ok, so this is none of the documented NMI sources,
+ * so it must be the NMI watchdog.
+ */
+ if (nmi_watchdog > 0) {
+ nmi_watchdog_tick(regs,reason);
+ return;
+ }
+#endif
+ unknown_nmi_error(reason, regs);
+ return;
+ }
+ if (notify_die(DIE_NMI, "nmi", regs, reason, 0, SIGINT) == NOTIFY_STOP)
+ return;
+
+ /* AK: following checks seem to be broken on modern chipsets. FIXME */
+
+ if (reason & 0x80)
+ mem_parity_error(reason, regs);
+ if (reason & 0x40)
+ io_check_error(reason, regs);
+}
+
+asmlinkage void do_int3(struct pt_regs * regs, long error_code)
+{
+ if (notify_die(DIE_INT3, "int3", regs, error_code, 3, SIGTRAP) == NOTIFY_STOP) {
+ return;
+ }
+ do_trap(3, SIGTRAP, "int3", regs, error_code, NULL);
+ return;
+}
+
+/* runs on IST stack. */
+asmlinkage void *do_debug(struct pt_regs * regs, unsigned long error_code)
+{
+ struct pt_regs *pr;
+ unsigned long condition;
+ struct task_struct *tsk = current;
+ siginfo_t info;
+
+ pr = (struct pt_regs *)(current->thread.rsp0)-1;
+ if (regs->cs & 3) {
+ memcpy(pr, regs, sizeof(struct pt_regs));
+ regs = pr;
+ }
+
+#ifdef CONFIG_CHECKING
+ {
+ /* RED-PEN interaction with debugger - could destroy gs */
+ unsigned long gs;
+ struct x8664_pda *pda = cpu_pda + safe_smp_processor_id();
+ rdmsrl(MSR_GS_BASE, gs);
+ if (gs != (unsigned long)pda) {
+ wrmsrl(MSR_GS_BASE, pda);
+ printk("debug handler: wrong gs %lx expected %p\n", gs, pda);
+ }
+ }
+#endif
+
+ asm("movq %%db6,%0" : "=r" (condition));
+
+ if (notify_die(DIE_DEBUG, "debug", regs, condition, error_code,
+ SIGTRAP) == NOTIFY_STOP) {
+ return regs;
+ }
+ conditional_sti(regs);
+
+ /* Mask out spurious debug traps due to lazy DR7 setting */
+ if (condition & (DR_TRAP0|DR_TRAP1|DR_TRAP2|DR_TRAP3)) {
+ if (!tsk->thread.debugreg7) {
+ goto clear_dr7;
+ }
+ }
+
+ tsk->thread.debugreg6 = condition;
+
+ /* Mask out spurious TF errors due to lazy TF clearing */
+ if ((condition & DR_STEP) &&
+ (notify_die(DIE_DEBUGSTEP, "debugstep", regs, condition,
+ 1, SIGTRAP) != NOTIFY_STOP)) {
+ /*
+ * The TF error should be masked out only if the current
+ * process is not traced and if the TRAP flag has been set
+ * previously by a tracing process (condition detected by
+ * the PT_DTRACE flag); remember that the i386 TRAP flag
+ * can be modified by the process itself in user mode,
+ * allowing programs to debug themselves without the ptrace()
+ * interface.
+ */
+ if ((regs->cs & 3) == 0)
+ goto clear_TF_reenable;
+ if ((tsk->ptrace & (PT_DTRACE|PT_PTRACED)) == PT_DTRACE)
+ goto clear_TF;
+ }
+
+ /* Ok, finally something we can handle */
+ tsk->thread.trap_no = 1;
+ tsk->thread.error_code = error_code;
+ info.si_signo = SIGTRAP;
+ info.si_errno = 0;
+ info.si_code = TRAP_BRKPT;
+ if ((regs->cs & 3) == 0)
+ goto clear_dr7;
+
+ info.si_addr = (void __user *)regs->rip;
+ force_sig_info(SIGTRAP, &info, tsk);
+clear_dr7:
+ asm volatile("movq %0,%%db7"::"r"(0UL));
+ notify_die(DIE_DEBUG, "debug", regs, condition, 1, SIGTRAP);
+ return regs;
+
+clear_TF_reenable:
+ set_tsk_thread_flag(tsk, TIF_SINGLESTEP);
+
+clear_TF:
+ /* RED-PEN could cause spurious errors */
+ if (notify_die(DIE_DEBUG, "debug2", regs, condition, 1, SIGTRAP)
+ != NOTIFY_STOP)
+ regs->eflags &= ~TF_MASK;
+ return regs;
+}
+
+static int kernel_math_error(struct pt_regs *regs, char *str)
+{
+ const struct exception_table_entry *fixup;
+ fixup = search_exception_tables(regs->rip);
+ if (fixup) {
+ regs->rip = fixup->fixup;
+ return 1;
+ }
+ notify_die(DIE_GPF, str, regs, 0, 16, SIGFPE);
+#if 0
+ /* This should be a die, but warn only for now */
+ die(str, regs, 0);
+#else
+ printk(KERN_DEBUG "%s: %s at ", current->comm, str);
+ printk_address(regs->rip);
+ printk("\n");
+#endif
+ return 0;
+}
+
+/*
+ * 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
+ */
+asmlinkage void do_coprocessor_error(struct pt_regs *regs)
+{
+ void __user *rip = (void __user *)(regs->rip);
+ struct task_struct * task;
+ siginfo_t info;
+ unsigned short cwd, swd;
+
+ conditional_sti(regs);
+ if ((regs->cs & 3) == 0 &&
+ kernel_math_error(regs, "kernel x87 math error"))
+ return;
+
+ /*
+ * Save the info for the exception handler and clear the error.
+ */
+ task = current;
+ save_init_fpu(task);
+ task->thread.trap_no = 16;
+ task->thread.error_code = 0;
+ info.si_signo = SIGFPE;
+ info.si_errno = 0;
+ info.si_code = __SI_FAULT;
+ info.si_addr = rip;
+ /*
+ * (~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);
+ switch (((~cwd) & swd & 0x3f) | (swd & 0x240)) {
+ case 0x000:
+ default:
+ break;
+ case 0x001: /* Invalid Op */
+ case 0x041: /* Stack Fault */
+ case 0x241: /* Stack Fault | Direction */
+ info.si_code = FPE_FLTINV;
+ break;
+ case 0x002: /* Denormalize */
+ case 0x010: /* Underflow */
+ info.si_code = FPE_FLTUND;
+ break;
+ case 0x004: /* Zero Divide */
+ info.si_code = FPE_FLTDIV;
+ break;
+ case 0x008: /* Overflow */
+ info.si_code = FPE_FLTOVF;
+ break;
+ case 0x020: /* Precision */
+ info.si_code = FPE_FLTRES;
+ break;
+ }
+ force_sig_info(SIGFPE, &info, task);
+}
+
+asmlinkage void bad_intr(void)
+{
+ printk("bad interrupt");
+}
+
+asmlinkage void do_simd_coprocessor_error(struct pt_regs *regs)
+{
+ void __user *rip = (void __user *)(regs->rip);
+ struct task_struct * task;
+ siginfo_t info;
+ unsigned short mxcsr;
+
+ conditional_sti(regs);
+ if ((regs->cs & 3) == 0 &&
+ kernel_math_error(regs, "simd math error"))
+ return;
+
+ /*
+ * Save the info for the exception handler and clear the error.
+ */
+ task = current;
+ save_init_fpu(task);
+ task->thread.trap_no = 19;
+ task->thread.error_code = 0;
+ info.si_signo = SIGFPE;
+ info.si_errno = 0;
+ info.si_code = __SI_FAULT;
+ info.si_addr = rip;
+ /*
+ * 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.
+ */
+ mxcsr = get_fpu_mxcsr(task);
+ switch (~((mxcsr & 0x1f80) >> 7) & (mxcsr & 0x3f)) {
+ case 0x000:
+ default:
+ break;
+ case 0x001: /* Invalid Op */
+ info.si_code = FPE_FLTINV;
+ break;
+ case 0x002: /* Denormalize */
+ case 0x010: /* Underflow */
+ info.si_code = FPE_FLTUND;
+ break;
+ case 0x004: /* Zero Divide */
+ info.si_code = FPE_FLTDIV;
+ break;
+ case 0x008: /* Overflow */
+ info.si_code = FPE_FLTOVF;
+ break;
+ case 0x020: /* Precision */
+ info.si_code = FPE_FLTRES;
+ break;
+ }
+ force_sig_info(SIGFPE, &info, task);
+}
+
+asmlinkage void do_spurious_interrupt_bug(struct pt_regs * regs)
+{
+}
+
+asmlinkage void __attribute__((weak)) smp_thermal_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.
+ */
+asmlinkage void math_state_restore(void)
+{
+ struct task_struct *me = current;
+ clts(); /* Allow maths ops (or we recurse) */
+
+ if (!used_math())
+ init_fpu(me);
+ restore_fpu_checking(&me->thread.i387.fxsave);
+ me->thread_info->status |= TS_USEDFPU;
+}
+
+void do_call_debug(struct pt_regs *regs)
+{
+ notify_die(DIE_CALL, "debug call", regs, 0, 255, SIGINT);
+}
+
+void __init trap_init(void)
+{
+ set_intr_gate(0,&divide_error);
+ set_intr_gate_ist(1,&debug,DEBUG_STACK);
+ set_intr_gate_ist(2,&nmi,NMI_STACK);
+ set_system_gate(3,&int3);
+ set_system_gate(4,&overflow); /* int4-5 can be called from all */
+ set_system_gate(5,&bounds);
+ set_intr_gate(6,&invalid_op);
+ set_intr_gate(7,&device_not_available);
+ set_intr_gate_ist(8,&double_fault, DOUBLEFAULT_STACK);
+ set_intr_gate(9,&coprocessor_segment_overrun);
+ set_intr_gate(10,&invalid_TSS);
+ set_intr_gate(11,&segment_not_present);
+ set_intr_gate_ist(12,&stack_segment,STACKFAULT_STACK);
+ set_intr_gate(13,&general_protection);
+ set_intr_gate(14,&page_fault);
+ set_intr_gate(15,&spurious_interrupt_bug);
+ set_intr_gate(16,&coprocessor_error);
+ set_intr_gate(17,&alignment_check);
+#ifdef CONFIG_X86_MCE
+ set_intr_gate_ist(18,&machine_check, MCE_STACK);
+#endif
+ set_intr_gate(19,&simd_coprocessor_error);
+
+#ifdef CONFIG_IA32_EMULATION
+ set_system_gate(IA32_SYSCALL_VECTOR, ia32_syscall);
+#endif
+
+ set_intr_gate(KDB_VECTOR, call_debug);
+
+ /*
+ * Should be a barrier for any external CPU state.
+ */
+ cpu_init();
+}
+
+
+/* Actual parsing is done early in setup.c. */
+static int __init oops_dummy(char *s)
+{
+ panic_on_oops = 1;
+ return -1;
+}
+__setup("oops=", oops_dummy);
+
+static int __init kstack_setup(char *s)
+{
+ kstack_depth_to_print = simple_strtoul(s,NULL,0);
+ return 0;
+}
+__setup("kstack=", kstack_setup);
+
generated by cgit v1.2.3-55-g7522 (git 2.39.0) at 2024-05-29 09:02:38 +0200