Commit 94438af4 authored by Thomas Gleixner's avatar Thomas Gleixner
Browse files

x86/idt: Add comments about early #PF handling 



The difference between 32 and 64 bit vs. early #PF handling is not
documented. Replace the FIXME at idt_setup_early_pf() with proper comments.

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200528145522.807135882@linutronix.de
parent bdf5bde8

arch/x86/kernel/idt.c

+8 −2
Original line number Diff line number Diff line
@@ -61,7 +61,11 @@ static bool idt_setup_done __initdata; 
static const __initconst struct idt_data early_idts[] = {

	INTG(X86_TRAP_DB,		asm_exc_debug),

	SYSG(X86_TRAP_BP,		asm_exc_int3),



#ifdef CONFIG_X86_32

	/*

	 * Not possible on 64-bit. See idt_setup_early_pf() for details.

	 */

	INTG(X86_TRAP_PF,		asm_exc_page_fault),

#endif

};
@@ -256,8 +260,10 @@ void __init idt_setup_traps(void) 
 * 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?

 * Note, that X86_64 cannot install the real #PF handler in

 * idt_setup_early_traps() because the memory intialization needs the #PF

 * handler from the early_idt_handler_array to initialize the early page

 * tables.

 */

void __init idt_setup_early_pf(void)

{

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