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/*
* 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
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