From: Vitaly Kuznetsov Date: Tue, 28 Apr 2020 09:38:23 +0000 (+0200) Subject: x86/idt: Annotate alloc_intr_gate() with __init X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=06184325a1cce27a02a688d98740f90fe06e0133;p=linux.git x86/idt: Annotate alloc_intr_gate() with __init 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 Signed-off-by: Vitaly Kuznetsov Signed-off-by: Thomas Gleixner Link: https://lkml.kernel.org/r/20200428093824.1451532-3-vkuznets@redhat.com --- diff --git a/arch/x86/kernel/idt.c b/arch/x86/kernel/idt.c index 98bcb502f9675..0e9205137de8a 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); }