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[PATCH] i386: Do better early exception handlers

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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 <ak@suse.de>
Cc: Andi Kleen <ak@muc.de>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
This commit is contained in:
Chuck Ebbert 2006-09-26 10:52:39 +02:00 committed by Andi Kleen
parent 78be3706b2
commit ec5c09269b
1 changed files with 67 additions and 0 deletions
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67
arch/i386/kernel/head.S
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@ -371,8 +371,65 @@ rp_sidt:
addl $8,%edi addl $8,%edi
dec %ecx dec %ecx
jne rp_sidt 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 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" :-) */ /* This is the default interrupt "handler" :-) */
ALIGN ALIGN
ignore_int: ignore_int:
@ -386,6 +443,9 @@ ignore_int:
movl $(__KERNEL_DS),%eax movl $(__KERNEL_DS),%eax
movl %eax,%ds movl %eax,%ds
movl %eax,%es movl %eax,%es
cmpl $2,early_recursion_flag
je hlt_loop
incl early_recursion_flag
pushl 16(%esp) pushl 16(%esp)
pushl 24(%esp) pushl 24(%esp)
pushl 32(%esp) pushl 32(%esp)
@ -431,9 +491,16 @@ ENTRY(stack_start)
ready: .byte 0 ready: .byte 0
early_recursion_flag:
.long 0
int_msg: int_msg:
.asciz "Unknown interrupt or fault at EIP %p %p %p\n" .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 * The IDT and GDT 'descriptors' are a strange 48-bit object
* only used by the lidt and lgdt instructions. They are not * only used by the lidt and lgdt instructions. They are not