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Thomas Gleixner authored
Moving the early IDT setup out of assembly code breaks the boot on first generation 486 systems. The reason is that the call of idt_setup_early_handler, which sets up the early handlers was added after the call to cr4_init_shadow(). cr4_init_shadow() tries to read CR4 which is not available on those systems. The accessor function uses a extable fixup to handle the resulting fault. As the IDT is not set up yet, the cr4 read exception causes an instantaneous reboot for obvious reasons. Call idt_setup_early_handler() before cr4_init_shadow() so IDT is set up before the first exception hits. Fixes: 87e81786 ("x86/idt: Move early IDT setup out of 32-bit asm") Reported-and-tested-by: Matthew Whitehead <whiteheadm@acm.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/alpine.DEB.2.20.1710161210290.1973@nanos
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