| 1 | .section ".text","ax" |
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| 2 | |
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| 3 | #define SIGTRAP 5 |
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| 4 | |
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| 5 | #define SIZEOF_I386_REGS 32 |
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| 6 | #define SIZEOF_I386_FLAGS 4 |
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| 7 | |
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| 8 | /* When invoked, the stack contains: eflags, cs, eip, signo. */ |
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| 9 | #define IH_OFFSET_GDB_REGS ( 0 ) |
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| 10 | #define IH_OFFSET_GDB_EIP ( IH_OFFSET_GDB_REGS + SIZEOF_I386_REGS ) |
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| 11 | #define IH_OFFSET_GDB_EFLAGS ( IH_OFFSET_GDB_EIP + 4 ) |
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| 12 | #define IH_OFFSET_GDB_SEG_REGS ( IH_OFFSET_GDB_EFLAGS + SIZEOF_I386_FLAGS ) |
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| 13 | #define IH_OFFSET_GDB_END ( IH_OFFSET_GDB_SEG_REGS + 6 * 4 ) |
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| 14 | #define IH_OFFSET_OLD_EIP ( IH_OFFSET_GDB_END ) |
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| 15 | #define IH_OFFSET_OLD_CS ( IH_OFFSET_OLD_EIP + 4 ) |
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| 16 | #define IH_OFFSET_OLD_EFLAGS ( IH_OFFSET_OLD_CS + 4 ) |
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| 17 | #define IH_OFFSET_END ( IH_OFFSET_OLD_EFLAGS + 4 ) |
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| 18 | |
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| 19 | /* We also access the stack whilst still storing or restoring |
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| 20 | * the register snapshot. Since ESP is in flux, we need |
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| 21 | * special offsets. |
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| 22 | */ |
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| 23 | #define IH_OFFSET_FLUX_OLD_CS ( IH_OFFSET_OLD_CS - 44 ) |
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| 24 | #define IH_OFFSET_FLUX_OLD_EFLAGS ( IH_OFFSET_OLD_EFLAGS - 40 ) |
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| 25 | #define IH_OFFSET_FLUX_OLD_EIP ( IH_OFFSET_OLD_EIP - 36 ) |
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| 26 | #define IH_OFFSET_FLUX_END ( IH_OFFSET_END - 20 ) |
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| 27 | |
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| 28 | .global int_handler |
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| 29 | int_handler: |
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| 30 | /* Store CPU state in GDB register snapshot */ |
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| 31 | pushw $0 |
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| 32 | pushw %gs |
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| 33 | pushw $0 |
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| 34 | pushw %fs |
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| 35 | pushw $0 |
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| 36 | pushw %es |
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| 37 | pushw $0 |
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| 38 | pushw %ds |
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| 39 | pushw $0 |
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| 40 | pushw %ss |
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| 41 | pushw $0 |
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| 42 | pushw IH_OFFSET_FLUX_OLD_CS + 2(%esp) |
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| 43 | pushl IH_OFFSET_FLUX_OLD_EFLAGS(%esp) |
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| 44 | pushl IH_OFFSET_FLUX_OLD_EIP(%esp) |
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| 45 | pushl %edi |
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| 46 | pushl %esi |
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| 47 | pushl %ebp |
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| 48 | leal IH_OFFSET_FLUX_END(%esp), %edi |
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| 49 | pushl %edi /* old ESP */ |
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| 50 | pushl %ebx |
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| 51 | pushl %edx |
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| 52 | pushl %ecx |
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| 53 | pushl %eax |
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| 54 | |
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| 55 | /* Call GDB stub exception handler */ |
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| 56 | movl $SIGTRAP, %eax |
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| 57 | movl %esp, %edx |
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| 58 | call gdbstub_handler |
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| 59 | |
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| 60 | /* Restore CPU state from GDB register snapshot */ |
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| 61 | popl %eax |
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| 62 | popl %ecx |
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| 63 | popl %edx |
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| 64 | popl %ebx |
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| 65 | addl $4, %esp /* Changing ESP currently not supported */ |
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| 66 | popl %ebp |
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| 67 | popl %esi |
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| 68 | popl %edi |
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| 69 | popl IH_OFFSET_FLUX_OLD_EIP(%esp) |
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| 70 | popl IH_OFFSET_FLUX_OLD_EFLAGS(%esp) |
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| 71 | popl IH_OFFSET_FLUX_OLD_CS(%esp) |
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| 72 | popl %ss |
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| 73 | popl %ds |
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| 74 | popl %es |
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| 75 | popl %fs |
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| 76 | popl %gs |
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| 77 | iret |
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