From 8866cd9dc9d0bbadcf361a14e0cdfecb66473087 Mon Sep 17 00:00:00 2001 From: Roland McGrath Date: Wed, 30 Jan 2008 13:33:06 +0100 Subject: [PATCH] x86: early_idt_handler improvements, 64-bit It's not too pretty, but I found this made the "PANIC: early exception" messages become much more reliably useful: 1. print the vector number, 2. print the %cs value, 3. handle error-code-pushing vs non-pushing vectors. Signed-off-by: Roland McGrath Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/x86/kernel/head64.c | 2 +- arch/x86/kernel/head_64.S | 34 ++++++++++++++++++++++++++++++---- include/asm-x86/segment.h | 6 ++++++ 3 files changed, 37 insertions(+), 5 deletions(-) diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c index 4a1c1356c41a..85c1e6bf8022 100644 --- a/arch/x86/kernel/head64.c +++ b/arch/x86/kernel/head64.c @@ -59,7 +59,7 @@ void __init x86_64_start_kernel(char * real_mode_data) zap_identity_mappings(); for (i = 0; i < IDT_ENTRIES; i++) - set_intr_gate(i, early_idt_handler); + set_intr_gate(i, &early_idt_handlers[i]); load_idt((const struct desc_ptr *)&idt_descr); early_printk("Kernel alive\n"); diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S index c31b1c96a9d3..8b4c35cb519a 100644 --- a/arch/x86/kernel/head_64.S +++ b/arch/x86/kernel/head_64.S @@ -267,14 +267,40 @@ init_rsp: bad_address: jmp bad_address +.macro early_idt_tramp first, last + .ifgt \last-\first + early_idt_tramp \first, \last-1 + .endif + movl $\last,%esi + jmp early_idt_handler +.endm + + .globl early_idt_handlers +early_idt_handlers: + early_idt_tramp 0, 63 + early_idt_tramp 64, 127 + early_idt_tramp 128, 191 + early_idt_tramp 192, 255 + ENTRY(early_idt_handler) cmpl $2,early_recursion_flag(%rip) jz 1f incl early_recursion_flag(%rip) - xorl %eax,%eax - movq 8(%rsp),%rsi # get rip - movq (%rsp),%rdx GET_CR2_INTO_RCX + movq %rcx,%r9 + xorl %r8d,%r8d # zero for error code + movl %esi,%ecx # get vector number + # Test %ecx against mask of vectors that push error code. + cmpl $31,%ecx + ja 0f + movl $1,%eax + salq %cl,%rax + testl $0x27d00,%eax + je 0f + popq %r8 # get error code +0: movq 0(%rsp),%rcx # get ip + movq 8(%rsp),%rdx # get cs + xorl %eax,%eax leaq early_idt_msg(%rip),%rdi call early_printk cmpl $2,early_recursion_flag(%rip) @@ -291,7 +317,7 @@ early_recursion_flag: .long 0 early_idt_msg: - .asciz "PANIC: early exception rip %lx error %lx cr2 %lx\n" + .asciz "PANIC: early exception %02lx rip %lx:%lx error %lx cr2 %lx\n" early_idt_ripmsg: .asciz "RIP %s\n" diff --git a/include/asm-x86/segment.h b/include/asm-x86/segment.h index 57c8d3723836..23f0535fec61 100644 --- a/include/asm-x86/segment.h +++ b/include/asm-x86/segment.h @@ -195,4 +195,10 @@ #define GDT_ENTRY_TLS_ENTRIES 3 #define TLS_SIZE (GDT_ENTRY_TLS_ENTRIES * 8) +#ifdef __KERNEL__ +#ifndef __ASSEMBLY__ +extern const char early_idt_handlers[IDT_ENTRIES][10]; +#endif +#endif + #endif -- 2.39.2