There seems to be no reason to allocate interrupt gates after init. Mark
alloc_intr_gate() as __init and add WARN_ON() checks making sure it is
only used before idt_setup_apic_and_irq_gates() finalizes IDT setup and
maps all un-allocated entries to spurious entries.
Suggested-by: Thomas Gleixner <t...@linutronix.de>
Signed-off-by: Vitaly Kuznetsov <vkuzn...@redhat.com>
---
arch/x86/kernel/idt.c | 16 +++++++++++++---
1 file changed, 13 insertions(+), 3 deletions(-)
diff --git a/arch/x86/kernel/idt.c b/arch/x86/kernel/idt.c
index 87ef69a72c52..f95c3be00e5a 100644
--- a/arch/x86/kernel/idt.c
+++ b/arch/x86/kernel/idt.c
@@ -51,6 +51,9 @@ struct idt_data {
#define TSKG(_vector, _gdt) \
G(_vector, NULL, DEFAULT_STACK, GATE_TASK, DPL0, _gdt << 3)
+
+static bool idt_setup_done __initdata;
+
/*
* Early traps running on the DEFAULT_STACK because the other interrupt
* stacks work only after cpu_init().
@@ -323,6 +326,7 @@ void __init idt_setup_apic_and_irq_gates(void)
set_intr_gate(i, entry);
}
#endif
+ idt_setup_done = true;
}
/**
@@ -352,6 +356,7 @@ void idt_invalidate(void *addr)
load_idt(&idt);
}
+/* This goes away once ASYNC_PF is sanitized */
void __init update_intr_gate(unsigned int n, const void *addr)
{
if (WARN_ON_ONCE(!test_bit(n, system_vectors)))
@@ -359,9 +364,14 @@ void __init update_intr_gate(unsigned int n, const void
*addr)
set_intr_gate(n, addr);
}
-void alloc_intr_gate(unsigned int n, const void *addr)
+void __init alloc_intr_gate(unsigned int n, const void *addr)
{
- BUG_ON(n < FIRST_SYSTEM_VECTOR);
- if (!test_and_set_bit(n, system_vectors))
+ if (WARN_ON(n < FIRST_SYSTEM_VECTOR))
+ return;
+
+ if (WARN_ON(idt_setup_done))
+ return;
+
+ if (!WARN_ON(test_and_set_bit(n, system_vectors)))
set_intr_gate(n, addr);
}
--
2.25.3
