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#include "config.h"
#define GLUE(a, b) a ## b
#define JOIN(a, b) GLUE(a, b)
#define MANGLE(s) JOIN(EXTERN_ASM, s)
.data
.globl MANGLE(caller_return)
MANGLE(caller_return):
.long 0
.globl MANGLE(report_entry)
MANGLE(report_entry):
.long MANGLE(null_call)
.globl MANGLE(report_ret)
MANGLE(report_ret):
.long MANGLE(null_call)
.global MANGLE(wrapper_target)
MANGLE(wrapper_target):
.long MANGLE(null_call)
.text
.globl MANGLE(null_call)
.type MANGLE(null_call), @function
.balign 16,0x90
MANGLE(null_call):
ret
.globl MANGLE(wrapper)
.type MANGLE(wrapper), @function
.balign 16,0x90
MANGLE(wrapper):
pusha # store registers (EAX, ECX, EDX, EBX, ESP, EBP, ESI, EDI)
pushf # store flags
push %ebp # set up a stack frame
movl %esp, %ebp
leal 4(%ebp), %eax # push flags addr
push %eax
leal 8(%ebp), %eax # push registers addr
push %eax
leal 40(%ebp), %edx
movl (%ebp), %eax
subl %edx, %eax
push %eax
push %edx
call *MANGLE(report_entry) # report entry
test %eax, %eax
jnz .Ldone
leave # restore %esp, %ebp
popf # restore flags
popa # restore registers
popl MANGLE(caller_return) # switch return addresses
pushl $.Lwrapper_return
jmp *MANGLE(wrapper_target) # wrapper_target should return at .Lwrapper_return
.balign 16, 0x90
.Lwrapper_return:
pushl MANGLE(caller_return) # restore the original return address
pusha # more for reference sake here
pushf
push %ebp # set up a stack frame
movl %esp, %ebp
leal 4(%ebp), %eax # push flags addr
push %eax
leal 8(%ebp), %eax # push registers addr
push %eax
leal 40(%ebp), %edx # push stack top address (relative to our entry)
movl (%ebp), %eax
subl %edx, %eax # calculate difference between entry and previous frame
push %eax
push %edx
call *MANGLE(report_ret) # report the return information (same args)
.Ldone:
leave
popf
popa
ret
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