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Commit 433f8924 authored by Thomas Gleixner's avatar Thomas Gleixner Committed by Ingo Molnar
Browse files

x86/idt: Switch early trap init to IDT tables 



Add the initialization table for the early trap setup and replace the early
trap init code.

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170828064958.929139008@linutronix.de


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 3318e974

arch/x86/kernel/idt.c

+53 −0
Original line number Diff line number Diff line
@@ -48,6 +48,28 @@ struct idt_data { 
#define TSKG(_vector, _gdt)				\

	G(_vector, NULL, DEFAULT_STACK, GATE_TASK, DPL0, _gdt << 3)



/*

 * Early traps running on the DEFAULT_STACK because the other interrupt

 * stacks work only after cpu_init().

 */

static const __initdata struct idt_data early_idts[] = {

	INTG(X86_TRAP_DB,		debug),

	SYSG(X86_TRAP_BP,		int3),

#ifdef CONFIG_X86_32

	INTG(X86_TRAP_PF,		page_fault),

#endif

};



#ifdef CONFIG_X86_64

/*

 * Early traps running on the DEFAULT_STACK because the other interrupt

 * stacks work only after cpu_init().

 */

static const __initdata struct idt_data early_pf_idts[] = {

	INTG(X86_TRAP_PF,		page_fault),

};

#endif



/* Must be page-aligned because the real IDT is used in a fixmap. */

gate_desc idt_table[IDT_ENTRIES] __page_aligned_bss;
@@ -92,6 +114,37 @@ idt_setup_from_table(gate_desc *idt, const struct idt_data *t, int size) 
	}

}



/**

 * idt_setup_early_traps - Initialize the idt table with early traps

 *

 * On X8664 these traps do not use interrupt stacks as they can't work

 * before cpu_init() is invoked and sets up TSS. The IST variants are

 * installed after that.

 */

void __init idt_setup_early_traps(void)

{

	idt_setup_from_table(idt_table, early_idts, ARRAY_SIZE(early_idts));

	load_idt(&idt_descr);

}



#ifdef CONFIG_X86_64

/**

 * idt_setup_early_pf - Initialize the idt table with early pagefault handler

 *

 * On X8664 this does not use interrupt stacks as they can't work before

 * cpu_init() is invoked and sets up TSS. The IST variant is installed

 * after that.

 *

 * FIXME: Why is 32bit and 64bit installing the PF handler at different

 * places in the early setup code?

 */

void __init idt_setup_early_pf(void)

{

	idt_setup_from_table(idt_table, early_pf_idts,

			     ARRAY_SIZE(early_pf_idts));

}

#endif



/**

 * idt_setup_early_handler - Initializes the idt table with early handlers

 */

arch/x86/kernel/setup.c

+2 −2
Original line number Diff line number Diff line
@@ -891,7 +891,7 @@ void __init setup_arch(char **cmdline_p) 
	 */

	olpc_ofw_detect();



	early_trap_init();

	idt_setup_early_traps();

	early_cpu_init();

	early_ioremap_init();
@@ -1162,7 +1162,7 @@ void __init setup_arch(char **cmdline_p) 


	init_mem_mapping();



	early_trap_pf_init();

	idt_setup_early_pf();



	/*

	 * Update mmu_cr4_features (and, indirectly, trampoline_cr4_features)

arch/x86/kernel/traps.c

+0 −27
Original line number Diff line number Diff line
@@ -923,33 +923,6 @@ dotraplinkage void do_iret_error(struct pt_regs *regs, long error_code) 
}

#endif



/* Set of traps needed for early debugging. */

void __init early_trap_init(void)

{

	/*

	 * Don't use IST to set DEBUG_STACK as it doesn't work until TSS

	 * is ready in cpu_init() <-- trap_init(). Before trap_init(),

	 * CPU runs at ring 0 so it is impossible to hit an invalid

	 * stack.  Using the original stack works well enough at this

	 * early stage. DEBUG_STACK will be equipped after cpu_init() in

	 * trap_init().

	 */

	set_intr_gate(X86_TRAP_DB, debug);

	/* int3 can be called from all */

	set_system_intr_gate(X86_TRAP_BP, &int3);

#ifdef CONFIG_X86_32

	set_intr_gate(X86_TRAP_PF, page_fault);

#endif

	load_idt(&idt_descr);

}



void __init early_trap_pf_init(void)

{

#ifdef CONFIG_X86_64

	set_intr_gate(X86_TRAP_PF, page_fault);

#endif

}



void __init trap_init(void)

{

	int i;