| /* |
| * Interrupt handlers for GDB stub |
| */ |
| |
| #define SIZEOF_I386_REGS 32 |
| #define SIZEOF_I386_FLAGS 4 |
| |
| /**************************************************************************** |
| * Interrupt handlers |
| **************************************************************************** |
| */ |
| .section ".note.GNU-stack", "", @progbits |
| .section ".text", "ax", @progbits |
| .code32 |
| |
| /* POSIX signal numbers for reporting traps to GDB */ |
| #define SIGILL 4 |
| #define SIGTRAP 5 |
| #define SIGFPE 8 |
| #define SIGSTKFLT 16 |
| |
| .globl gdbmach_sigfpe |
| gdbmach_sigfpe: |
| pushl $SIGFPE |
| jmp gdbmach_interrupt |
| |
| .globl gdbmach_sigtrap |
| gdbmach_sigtrap: |
| pushl $SIGTRAP |
| jmp gdbmach_interrupt |
| |
| .globl gdbmach_sigstkflt |
| gdbmach_sigstkflt: |
| pushl $SIGSTKFLT |
| jmp gdbmach_interrupt |
| |
| .globl gdbmach_sigill |
| gdbmach_sigill: |
| pushl $SIGILL |
| jmp gdbmach_interrupt |
| |
| /* When invoked, the stack contains: eflags, cs, eip, signo. */ |
| #define IH_OFFSET_GDB_REGS ( 0 ) |
| #define IH_OFFSET_GDB_EIP ( IH_OFFSET_GDB_REGS + SIZEOF_I386_REGS ) |
| #define IH_OFFSET_GDB_EFLAGS ( IH_OFFSET_GDB_EIP + 4 ) |
| #define IH_OFFSET_GDB_SEG_REGS ( IH_OFFSET_GDB_EFLAGS + SIZEOF_I386_FLAGS ) |
| #define IH_OFFSET_GDB_END ( IH_OFFSET_GDB_SEG_REGS + 6 * 4 ) |
| #define IH_OFFSET_SIGNO ( IH_OFFSET_GDB_END ) |
| #define IH_OFFSET_OLD_EIP ( IH_OFFSET_SIGNO + 4 ) |
| #define IH_OFFSET_OLD_CS ( IH_OFFSET_OLD_EIP + 4 ) |
| #define IH_OFFSET_OLD_EFLAGS ( IH_OFFSET_OLD_CS + 4 ) |
| #define IH_OFFSET_END ( IH_OFFSET_OLD_EFLAGS + 4 ) |
| |
| /* We also access the stack whilst still storing or restoring |
| * the register snapshot. Since ESP is in flux, we need |
| * special offsets. |
| */ |
| #define IH_OFFSET_FLUX_OLD_CS ( IH_OFFSET_OLD_CS - 44 ) |
| #define IH_OFFSET_FLUX_OLD_EFLAGS ( IH_OFFSET_OLD_EFLAGS - 40 ) |
| #define IH_OFFSET_FLUX_OLD_EIP ( IH_OFFSET_OLD_EIP - 36 ) |
| #define IH_OFFSET_FLUX_END ( IH_OFFSET_END - 20 ) |
| gdbmach_interrupt: |
| /* Store CPU state in GDB register snapshot */ |
| pushw $0 |
| pushw %gs |
| pushw $0 |
| pushw %fs |
| pushw $0 |
| pushw %es |
| pushw $0 |
| pushw %ds |
| pushw $0 |
| pushw %ss |
| pushw $0 |
| pushw IH_OFFSET_FLUX_OLD_CS + 2(%esp) |
| pushl IH_OFFSET_FLUX_OLD_EFLAGS(%esp) |
| pushl IH_OFFSET_FLUX_OLD_EIP(%esp) |
| pushl %edi |
| pushl %esi |
| pushl %ebp |
| leal IH_OFFSET_FLUX_END(%esp), %edi |
| pushl %edi /* old ESP */ |
| pushl %ebx |
| pushl %edx |
| pushl %ecx |
| pushl %eax |
| |
| /* Switch to virtual addressing */ |
| call _intr_to_virt |
| |
| /* Call GDB stub exception handler */ |
| pushl %esp |
| pushl (IH_OFFSET_SIGNO + 4)(%esp) |
| call gdbmach_handler |
| addl $8, %esp |
| |
| /* Copy register snapshot to new stack and switch to new stack */ |
| movl %esp, %esi |
| movl (IH_OFFSET_GDB_SEG_REGS + 4)(%esp), %eax |
| movl %eax, %es |
| movl (IH_OFFSET_GDB_REGS + 16)(%esp), %edi |
| subl $IH_OFFSET_END, %edi |
| movl $(IH_OFFSET_END / 4), %ecx |
| pushl %edi |
| ss rep movsl |
| popl %edi |
| movl %eax, %ss |
| movl %edi, %esp |
| |
| /* Restore CPU state from GDB register snapshot */ |
| popl %eax |
| popl %ecx |
| popl %edx |
| popl %ebx |
| popl %ebp /* Skip %esp: already loaded */ |
| popl %ebp |
| popl %esi |
| popl %edi |
| popl IH_OFFSET_FLUX_OLD_EIP(%esp) |
| popl IH_OFFSET_FLUX_OLD_EFLAGS(%esp) |
| popl IH_OFFSET_FLUX_OLD_CS(%esp) |
| popl %ds /* Skip %ss: already loaded */ |
| popl %ds |
| popl %es |
| popl %fs |
| popl %gs |
| |
| addl $4, %esp /* drop signo */ |
| iret |
