The following commit has been merged into the x86/entry branch of tip: Commit-ID: 66d2e706c0cecd09b1f3de4844574d30e5469c28 Gitweb: https://git.kernel.org/tip/66d2e706c0cecd09b1f3de4844574d30e5469c28 Author: Thomas Gleixner <t...@linutronix.de> AuthorDate: Thu, 28 May 2020 16:53:17 +02:00 Committer: Thomas Gleixner <t...@linutronix.de> CommitterDate: Sat, 30 May 2020 11:50:11 +02:00
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: Thomas Gleixner <t...@linutronix.de> Link: https://lkml.kernel.org/r/20200528145522.807135...@linutronix.de --- arch/x86/kernel/idt.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/idt.c b/arch/x86/kernel/idt.c index 4b99f7b..5ef82fc 100644 --- a/arch/x86/kernel/idt.c +++ b/arch/x86/kernel/idt.c @@ -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) {
