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-rw-r--r--arch/x86/kernel/traps.c188
1 files changed, 21 insertions, 167 deletions
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index 9682ec50180..482ec3af206 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -81,15 +81,6 @@ gate_desc idt_table[NR_VECTORS] __page_aligned_data = { { { { 0, 0 } } }, };
DECLARE_BITMAP(used_vectors, NR_VECTORS);
EXPORT_SYMBOL_GPL(used_vectors);
-static int ignore_nmis;
-
-int unknown_nmi_panic;
-/*
- * Prevent NMI reason port (0x61) being accessed simultaneously, can
- * only be used in NMI handler.
- */
-static DEFINE_RAW_SPINLOCK(nmi_reason_lock);
-
static inline void conditional_sti(struct pt_regs *regs)
{
if (regs->flags & X86_EFLAGS_IF)
@@ -307,152 +298,6 @@ gp_in_kernel:
die("general protection fault", regs, error_code);
}
-static int __init setup_unknown_nmi_panic(char *str)
-{
- unknown_nmi_panic = 1;
- return 1;
-}
-__setup("unknown_nmi_panic", setup_unknown_nmi_panic);
-
-static notrace __kprobes void
-pci_serr_error(unsigned char reason, struct pt_regs *regs)
-{
- pr_emerg("NMI: PCI system error (SERR) for reason %02x on CPU %d.\n",
- reason, smp_processor_id());
-
- /*
- * On some machines, PCI SERR line is used to report memory
- * errors. EDAC makes use of it.
- */
-#if defined(CONFIG_EDAC)
- if (edac_handler_set()) {
- edac_atomic_assert_error();
- return;
- }
-#endif
-
- if (panic_on_unrecovered_nmi)
- panic("NMI: Not continuing");
-
- pr_emerg("Dazed and confused, but trying to continue\n");
-
- /* Clear and disable the PCI SERR error line. */
- reason = (reason & NMI_REASON_CLEAR_MASK) | NMI_REASON_CLEAR_SERR;
- outb(reason, NMI_REASON_PORT);
-}
-
-static notrace __kprobes void
-io_check_error(unsigned char reason, struct pt_regs *regs)
-{
- unsigned long i;
-
- pr_emerg(
- "NMI: IOCK error (debug interrupt?) for reason %02x on CPU %d.\n",
- reason, smp_processor_id());
- show_registers(regs);
-
- if (panic_on_io_nmi)
- panic("NMI IOCK error: Not continuing");
-
- /* Re-enable the IOCK line, wait for a few seconds */
- reason = (reason & NMI_REASON_CLEAR_MASK) | NMI_REASON_CLEAR_IOCHK;
- outb(reason, NMI_REASON_PORT);
-
- i = 20000;
- while (--i) {
- touch_nmi_watchdog();
- udelay(100);
- }
-
- reason &= ~NMI_REASON_CLEAR_IOCHK;
- outb(reason, NMI_REASON_PORT);
-}
-
-static notrace __kprobes void
-unknown_nmi_error(unsigned char reason, struct pt_regs *regs)
-{
- if (notify_die(DIE_NMIUNKNOWN, "nmi", regs, reason, 2, SIGINT) ==
- NOTIFY_STOP)
- return;
-#ifdef CONFIG_MCA
- /*
- * Might actually be able to figure out what the guilty party
- * is:
- */
- if (MCA_bus) {
- mca_handle_nmi();
- return;
- }
-#endif
- pr_emerg("Uhhuh. NMI received for unknown reason %02x on CPU %d.\n",
- reason, smp_processor_id());
-
- pr_emerg("Do you have a strange power saving mode enabled?\n");
- if (unknown_nmi_panic || panic_on_unrecovered_nmi)
- panic("NMI: Not continuing");
-
- pr_emerg("Dazed and confused, but trying to continue\n");
-}
-
-static notrace __kprobes void default_do_nmi(struct pt_regs *regs)
-{
- unsigned char reason = 0;
-
- /*
- * CPU-specific NMI must be processed before non-CPU-specific
- * NMI, otherwise we may lose it, because the CPU-specific
- * NMI can not be detected/processed on other CPUs.
- */
- if (notify_die(DIE_NMI, "nmi", regs, 0, 2, SIGINT) == NOTIFY_STOP)
- return;
-
- /* Non-CPU-specific NMI: NMI sources can be processed on any CPU */
- raw_spin_lock(&nmi_reason_lock);
- reason = get_nmi_reason();
-
- if (reason & NMI_REASON_MASK) {
- if (reason & NMI_REASON_SERR)
- pci_serr_error(reason, regs);
- else if (reason & NMI_REASON_IOCHK)
- io_check_error(reason, regs);
-#ifdef CONFIG_X86_32
- /*
- * Reassert NMI in case it became active
- * meanwhile as it's edge-triggered:
- */
- reassert_nmi();
-#endif
- raw_spin_unlock(&nmi_reason_lock);
- return;
- }
- raw_spin_unlock(&nmi_reason_lock);
-
- unknown_nmi_error(reason, regs);
-}
-
-dotraplinkage notrace __kprobes void
-do_nmi(struct pt_regs *regs, long error_code)
-{
- nmi_enter();
-
- inc_irq_stat(__nmi_count);
-
- if (!ignore_nmis)
- default_do_nmi(regs);
-
- nmi_exit();
-}
-
-void stop_nmi(void)
-{
- ignore_nmis++;
-}
-
-void restart_nmi(void)
-{
- ignore_nmis--;
-}
-
/* May run on IST stack. */
dotraplinkage void __kprobes do_int3(struct pt_regs *regs, long error_code)
{
@@ -461,19 +306,20 @@ dotraplinkage void __kprobes do_int3(struct pt_regs *regs, long error_code)
== NOTIFY_STOP)
return;
#endif /* CONFIG_KGDB_LOW_LEVEL_TRAP */
-#ifdef CONFIG_KPROBES
+
if (notify_die(DIE_INT3, "int3", regs, error_code, 3, SIGTRAP)
== NOTIFY_STOP)
return;
-#else
- if (notify_die(DIE_TRAP, "int3", regs, error_code, 3, SIGTRAP)
- == NOTIFY_STOP)
- return;
-#endif
+ /*
+ * 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(3, SIGTRAP, "int3", regs, error_code, NULL);
preempt_conditional_cli(regs);
+ debug_stack_usage_dec();
}
#ifdef CONFIG_X86_64
@@ -566,6 +412,12 @@ dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long 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);
@@ -573,6 +425,7 @@ dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code)
handle_vm86_trap((struct kernel_vm86_regs *) regs,
error_code, 1);
preempt_conditional_cli(regs);
+ debug_stack_usage_dec();
return;
}
@@ -592,6 +445,7 @@ dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code)
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;
}
@@ -872,16 +726,16 @@ void __init trap_init(void)
set_bit(SYSCALL_VECTOR, used_vectors);
#endif
-#ifdef CONFIG_X86_64
- BUG_ON(test_bit(VSYSCALL_EMU_VECTOR, used_vectors));
- set_system_intr_gate(VSYSCALL_EMU_VECTOR, &emulate_vsyscall);
- set_bit(VSYSCALL_EMU_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(1, &debug);
+ set_nmi_gate(3, &int3);
+#endif
}
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-02-18 10:54:11 +0000