From 0e861fbb5bda79b871341ef2a9a8059765cbe8a4 Mon Sep 17 00:00:00 2001 From: Andy Lutomirski Date: Sat, 2 Apr 2016 07:01:34 -0700 Subject: x86/head: Move early exception panic code into early_fixup_exception() This removes a bunch of assembly and adds some C code instead. It changes the actual printouts on both 32-bit and 64-bit kernels, but they still seem okay. Tested-by: Boris Ostrovsky Signed-off-by: Andy Lutomirski Acked-by: Linus Torvalds Cc: Andrew Morton Cc: Arjan van de Ven Cc: Borislav Petkov Cc: KVM list Cc: Paolo Bonzini Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: xen-devel Link: http://lkml.kernel.org/r/4085070316fc3ab29538d3fcfe282648d1d4ee2e.1459605520.git.luto@kernel.org Signed-off-by: Ingo Molnar --- arch/x86/mm/extable.c | 29 ++++++++++++++++++++++++----- 1 file changed, 24 insertions(+), 5 deletions(-) (limited to 'arch/x86/mm') diff --git a/arch/x86/mm/extable.c b/arch/x86/mm/extable.c index 4be041910c2f..da442f37ca8b 100644 --- a/arch/x86/mm/extable.c +++ b/arch/x86/mm/extable.c @@ -83,8 +83,10 @@ int fixup_exception(struct pt_regs *regs, int trapnr) return handler(e, regs, trapnr); } +extern unsigned int early_recursion_flag; + /* Restricted version used during very early boot */ -int __init early_fixup_exception(struct pt_regs *regs, int trapnr) +void __init early_fixup_exception(struct pt_regs *regs, int trapnr) { const struct exception_table_entry *e; unsigned long new_ip; @@ -92,19 +94,36 @@ int __init early_fixup_exception(struct pt_regs *regs, int trapnr) /* Ignore early NMIs. */ if (trapnr == X86_TRAP_NMI) - return 1; + return; + + if (early_recursion_flag > 2) + goto halt_loop; + + if (regs->cs != __KERNEL_CS) + goto fail; e = search_exception_tables(regs->ip); if (!e) - return 0; + goto fail; new_ip = ex_fixup_addr(e); handler = ex_fixup_handler(e); /* special handling not supported during early boot */ if (handler != ex_handler_default) - return 0; + goto fail; regs->ip = new_ip; - return 1; + return; + +fail: + early_printk("PANIC: early exception 0x%02x IP %lx:%lx error %lx cr2 0x%lx\n", + (unsigned)trapnr, (unsigned long)regs->cs, regs->ip, + regs->orig_ax, read_cr2()); + + show_regs(regs); + +halt_loop: + while (true) + halt(); } -- cgit v1.2.3