d1705c558c
Latest kernel has a kernel panic in booting on i386 machine when profile=2 setting in cmdline. It is due to 'sp' being incorrect in profile_pc(). BUG: unable to handle kernel NULL pointer dereference at 00000246 IP: [<c01288b6>] profile_pc+0x2a/0x48 *pde = 00000000 Oops: 0000 [#1] SMP This differs from the original version by Alex Shi in that we use the kernel_stack_pointer() inline already defined in <asm/ptrace.h> for this purpose, instead of #ifdef. Originally-by: Alex Shi <alex.shi@intel.com> Cc: "Chen, Tim C" <tim.c.chen@intel.com> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
122 lines
2.7 KiB
C
122 lines
2.7 KiB
C
/*
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* Copyright (c) 1991,1992,1995 Linus Torvalds
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* Copyright (c) 1994 Alan Modra
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* Copyright (c) 1995 Markus Kuhn
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* Copyright (c) 1996 Ingo Molnar
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* Copyright (c) 1998 Andrea Arcangeli
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* Copyright (c) 2002,2006 Vojtech Pavlik
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* Copyright (c) 2003 Andi Kleen
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*
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*/
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#include <linux/clockchips.h>
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#include <linux/interrupt.h>
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#include <linux/time.h>
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#include <linux/mca.h>
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#include <asm/vsyscall.h>
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#include <asm/x86_init.h>
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#include <asm/i8259.h>
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#include <asm/i8253.h>
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#include <asm/timer.h>
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#include <asm/hpet.h>
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#include <asm/time.h>
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#if defined(CONFIG_X86_32) && defined(CONFIG_X86_IO_APIC)
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int timer_ack;
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#endif
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#ifdef CONFIG_X86_64
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volatile unsigned long __jiffies __section_jiffies = INITIAL_JIFFIES;
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#endif
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unsigned long profile_pc(struct pt_regs *regs)
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{
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unsigned long pc = instruction_pointer(regs);
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if (!user_mode_vm(regs) && in_lock_functions(pc)) {
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#ifdef CONFIG_FRAME_POINTER
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return *(unsigned long *)(regs->bp + sizeof(long));
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#else
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unsigned long *sp =
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(unsigned long *)kernel_stack_pointer(regs);
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/*
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* Return address is either directly at stack pointer
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* or above a saved flags. Eflags has bits 22-31 zero,
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* kernel addresses don't.
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*/
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if (sp[0] >> 22)
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return sp[0];
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if (sp[1] >> 22)
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return sp[1];
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#endif
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}
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return pc;
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}
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EXPORT_SYMBOL(profile_pc);
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/*
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* Default timer interrupt handler for PIT/HPET
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*/
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static irqreturn_t timer_interrupt(int irq, void *dev_id)
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{
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/* Keep nmi watchdog up to date */
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inc_irq_stat(irq0_irqs);
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/* Optimized out for !IO_APIC and x86_64 */
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if (timer_ack) {
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/*
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* Subtle, when I/O APICs are used we have to ack timer IRQ
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* manually to deassert NMI lines for the watchdog if run
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* on an 82489DX-based system.
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*/
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spin_lock(&i8259A_lock);
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outb(0x0c, PIC_MASTER_OCW3);
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/* Ack the IRQ; AEOI will end it automatically. */
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inb(PIC_MASTER_POLL);
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spin_unlock(&i8259A_lock);
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}
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global_clock_event->event_handler(global_clock_event);
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/* MCA bus quirk: Acknowledge irq0 by setting bit 7 in port 0x61 */
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if (MCA_bus)
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outb_p(inb_p(0x61)| 0x80, 0x61);
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return IRQ_HANDLED;
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}
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static struct irqaction irq0 = {
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.handler = timer_interrupt,
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.flags = IRQF_DISABLED | IRQF_NOBALANCING | IRQF_IRQPOLL | IRQF_TIMER,
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.name = "timer"
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};
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void __init setup_default_timer_irq(void)
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{
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setup_irq(0, &irq0);
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}
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/* Default timer init function */
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void __init hpet_time_init(void)
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{
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if (!hpet_enable())
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setup_pit_timer();
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setup_default_timer_irq();
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}
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static __init void x86_late_time_init(void)
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{
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x86_init.timers.timer_init();
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tsc_init();
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}
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/*
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* Initialize TSC and delay the periodic timer init to
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* late x86_late_time_init() so ioremap works.
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*/
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void __init time_init(void)
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{
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late_time_init = x86_late_time_init;
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}
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