Messages in this thread Patch in this message | | | From | Vitaly Kuznetsov <> | Subject | [PATCH v2 2/3] x86/idt: Annotate alloc_intr_gate() with __init | Date | Tue, 28 Apr 2020 11:38:23 +0200 |
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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 <tglx@linutronix.de> Signed-off-by: Vitaly Kuznetsov <vkuznets@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
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