From 90f6225fba0c732f3f5f9f5e265bdefa021ff12d Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Mon, 28 Aug 2017 08:47:52 +0200 Subject: [PATCH] x86/idt: Move IST stack based traps to table init Initialize the IST based traps via a table. Signed-off-by: Thomas Gleixner Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Josh Poimboeuf Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Steven Rostedt Link: http://lkml.kernel.org/r/20170828064959.091328949@linutronix.de Signed-off-by: Ingo Molnar --- arch/x86/include/asm/desc.h | 2 ++ arch/x86/kernel/idt.c | 22 ++++++++++++++++++++++ arch/x86/kernel/traps.c | 9 +-------- 3 files changed, 25 insertions(+), 8 deletions(-) diff --git a/arch/x86/include/asm/desc.h b/arch/x86/include/asm/desc.h index 930acd5d85f6..e62452777067 100644 --- a/arch/x86/include/asm/desc.h +++ b/arch/x86/include/asm/desc.h @@ -509,9 +509,11 @@ extern void idt_setup_early_traps(void); #ifdef CONFIG_X86_64 extern void idt_setup_early_pf(void); +extern void idt_setup_ist_traps(void); extern void idt_setup_debugidt_traps(void); #else static inline void idt_setup_early_pf(void) { } +static inline void idt_setup_ist_traps(void) { } static inline void idt_setup_debugidt_traps(void) { } #endif diff --git a/arch/x86/kernel/idt.c b/arch/x86/kernel/idt.c index f5281b8f1131..a6326fd6698a 100644 --- a/arch/x86/kernel/idt.c +++ b/arch/x86/kernel/idt.c @@ -91,6 +91,20 @@ struct desc_ptr idt_descr __ro_after_init = { /* No need to be aligned, but done to keep all IDTs defined the same way. */ gate_desc debug_idt_table[IDT_ENTRIES] __page_aligned_bss; +/* + * The exceptions which use Interrupt stacks. They are setup after + * cpu_init() when the TSS has been initialized. + */ +static const __initdata struct idt_data ist_idts[] = { + ISTG(X86_TRAP_DB, debug, DEBUG_STACK), + ISTG(X86_TRAP_NMI, nmi, NMI_STACK), + ISTG(X86_TRAP_BP, int3, DEBUG_STACK), + ISTG(X86_TRAP_DF, double_fault, DOUBLEFAULT_STACK), +#ifdef CONFIG_X86_MCE + ISTG(X86_TRAP_MC, &machine_check, MCE_STACK), +#endif +}; + /* * Override for the debug_idt. Same as the default, but with interrupt * stack set to DEFAULT_STACK (0). Required for NMI trap handling. @@ -157,6 +171,14 @@ void __init idt_setup_early_pf(void) ARRAY_SIZE(early_pf_idts)); } +/** + * idt_setup_ist_traps - Initialize the idt table with traps using IST + */ +void __init idt_setup_ist_traps(void) +{ + idt_setup_from_table(idt_table, ist_idts, ARRAY_SIZE(ist_idts)); +} + /** * idt_setup_debugidt_traps - Initialize the debug idt table with debug traps */ diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index 1492bf5eb549..293f5bddd761 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -979,14 +979,7 @@ void __init trap_init(void) */ cpu_init(); - /* - * X86_TRAP_DB and X86_TRAP_BP have been set - * in early_trap_init(). However, ITS works only after - * cpu_init() loads TSS. See comments in early_trap_init(). - */ - set_intr_gate_ist(X86_TRAP_DB, &debug, DEBUG_STACK); - /* int3 can be called from all */ - set_system_intr_gate_ist(X86_TRAP_BP, &int3, DEBUG_STACK); + idt_setup_ist_traps(); x86_init.irqs.trap_init(); -- 2.20.1