From ec5c09269ba9cd3b9cf879390db6d5c7dcdcaf1e Mon Sep 17 00:00:00 2001 From: Chuck Ebbert <76306.1226@compuserve.com> Date: Tue, 26 Sep 2006 10:52:39 +0200 Subject: [PATCH] [PATCH] i386: Do better early exception handlers Add early i386 fault handlers with debug information for common faults. Handles: divide error invalid opcode protection fault page fault Also adds code to detect early recursive/multiple faults and halt the system when they happen (taken from x86_64.) Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com> Signed-off-by: Andi Kleen Cc: Andi Kleen Cc: Ingo Molnar Signed-off-by: Andrew Morton --- arch/i386/kernel/head.S | 67 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 67 insertions(+) diff --git a/arch/i386/kernel/head.S b/arch/i386/kernel/head.S index a6b8bd89aa27..be9d883c62ce 100644 --- a/arch/i386/kernel/head.S +++ b/arch/i386/kernel/head.S @@ -371,8 +371,65 @@ rp_sidt: addl $8,%edi dec %ecx jne rp_sidt + +.macro set_early_handler handler,trapno + lea \handler,%edx + movl $(__KERNEL_CS << 16),%eax + movw %dx,%ax + movw $0x8E00,%dx /* interrupt gate - dpl=0, present */ + lea idt_table,%edi + movl %eax,8*\trapno(%edi) + movl %edx,8*\trapno+4(%edi) +.endm + + set_early_handler handler=early_divide_err,trapno=0 + set_early_handler handler=early_illegal_opcode,trapno=6 + set_early_handler handler=early_protection_fault,trapno=13 + set_early_handler handler=early_page_fault,trapno=14 + ret +early_divide_err: + xor %edx,%edx + pushl $0 /* fake errcode */ + jmp early_fault + +early_illegal_opcode: + movl $6,%edx + pushl $0 /* fake errcode */ + jmp early_fault + +early_protection_fault: + movl $13,%edx + jmp early_fault + +early_page_fault: + movl $14,%edx + jmp early_fault + +early_fault: + cld +#ifdef CONFIG_PRINTK + movl $(__KERNEL_DS),%eax + movl %eax,%ds + movl %eax,%es + cmpl $2,early_recursion_flag + je hlt_loop + incl early_recursion_flag + movl %cr2,%eax + pushl %eax + pushl %edx /* trapno */ + pushl $fault_msg +#ifdef CONFIG_EARLY_PRINTK + call early_printk +#else + call printk +#endif +#endif +hlt_loop: + hlt + jmp hlt_loop + /* This is the default interrupt "handler" :-) */ ALIGN ignore_int: @@ -386,6 +443,9 @@ ignore_int: movl $(__KERNEL_DS),%eax movl %eax,%ds movl %eax,%es + cmpl $2,early_recursion_flag + je hlt_loop + incl early_recursion_flag pushl 16(%esp) pushl 24(%esp) pushl 32(%esp) @@ -431,9 +491,16 @@ ENTRY(stack_start) ready: .byte 0 +early_recursion_flag: + .long 0 + int_msg: .asciz "Unknown interrupt or fault at EIP %p %p %p\n" +fault_msg: + .ascii "Int %d: CR2 %p err %p EIP %p CS %p flags %p\n" + .asciz "Stack: %p %p %p %p %p %p %p %p\n" + /* * The IDT and GDT 'descriptors' are a strange 48-bit object * only used by the lidt and lgdt instructions. They are not -- 2.20.1