Hello forum,
I try to run my program and i came across this error:
Floating point exception (core dumped)
when I step in with pwndbg i came across this error:
Program terminated with signal SIGFPE, Arithmetic exception. (at the line divq %rdi)
I'm interested in this behavior, why the program crash here ?
If anybody has a fix also
Here is the source code
I comple with gcc and i get this from gnu documentation
I try to run my program and i came across this error:
Floating point exception (core dumped)
when I step in with pwndbg i came across this error:
Program terminated with signal SIGFPE, Arithmetic exception. (at the line divq %rdi)
I'm interested in this behavior, why the program crash here ?
If anybody has a fix also
Here is the source code
C:
#this program call odd_even write in ASM
int odd_even(int);
int main(){
return odd_even(4);
}
Код:
#this program check if the number is odd or even then call a function
.globl odd_even
.type odd_even, @function
.section .text
odd_even:
movq %rdi, %rax
movq $2, %rdi
divq %rdi #ERROR OCCUR HERE
movq $0, %rdx
cmpq $0, %rdx
je even
jmp odd
even:
call factorial
leave
ret
odd:
call exponent
leave
ret
Код:
.globl exponent
.type exponent, @function
.section .text
exponent:
movq $0, %rax
addq %rdi, %rax
mulq %rdi
mulq %rdi
leave
ret
Код:
.globl factorial
.type factorial, @function
.section .data
.equ OFFSET_FRAME, -8
.section .text
factorial:
enter $16, $0
movq $0, %rax
addq %rdi, %rax
movq %rdi, OFFSET_FRAME(%rbp)
mainloop:
cmpq $0, OFFSET_FRAME(%rbp)
je finish
mulq OFFSET_FRAME(%rbp)
decq OFFSET_FRAME(%rbp)
jmp mainloop
finish:
leave
retI comple with gcc and i get this from gnu documentation
Macro: int SIGFPE
The SIGFPE signal reports a fatal arithmetic error. Although thename is derived from “floating-point exception”, this signal actuallycovers all arithmetic errors, including division by zero and overflow.If a program stores integer data in a location which is then used in afloating-point operation, this often causes an “invalid operation”exception, because the processor cannot recognize the data as afloating-point number.
Actual floating-point exceptions are a complicated subject because thereare many types of exceptions with subtly different meanings, and theSIGFPE signal doesn’t distinguish between them. The IEEEStandard for Binary Floating-Point Arithmetic (ANSI/IEEE Std 754-1985and ANSI/IEEE Std 854-1987)defines various floating-point exceptions and requires conformingcomputer systems to report their occurrences. However, this standarddoes not specify how the exceptions are reported, or what kinds ofhandling and control the operating system can offer to the programmer.
BSD systems provide the SIGFPE handler with an extra argumentthat distinguishes various causes of the exception. In order to accessthis argument, you must define the handler to accept two arguments,which means you must cast it to a one-argument function type in order toestablish the handler. The GNU C Library does provide this extraargument, but the value is meaningful only on operating systems thatprovide the information (BSD systems and GNU systems).
FPE_INTOVF_TRAP
Integer overflow (impossible in a C program unless you enable overflowtrapping in a hardware-specific fashion).
FPE_INTDIV_TRAP
Integer division by zero.
FPE_SUBRNG_TRAP
Subscript-range (something that C programs never check for).
FPE_FLTOVF_TRAP
Floating overflow trap.
FPE_FLTDIV_TRAP
Floating/decimal division by zero.
FPE_FLTUND_TRAP
Floating underflow trap. (Trapping on floating underflow is notnormally enabled.)
FPE_DECOVF_TRAP
Decimal overflow trap. (Only a few machines have decimal arithmetic andC never uses it.)
The SIGFPE signal reports a fatal arithmetic error. Although thename is derived from “floating-point exception”, this signal actuallycovers all arithmetic errors, including division by zero and overflow.If a program stores integer data in a location which is then used in afloating-point operation, this often causes an “invalid operation”exception, because the processor cannot recognize the data as afloating-point number.
Actual floating-point exceptions are a complicated subject because thereare many types of exceptions with subtly different meanings, and theSIGFPE signal doesn’t distinguish between them. The IEEEStandard for Binary Floating-Point Arithmetic (ANSI/IEEE Std 754-1985and ANSI/IEEE Std 854-1987)defines various floating-point exceptions and requires conformingcomputer systems to report their occurrences. However, this standarddoes not specify how the exceptions are reported, or what kinds ofhandling and control the operating system can offer to the programmer.
BSD systems provide the SIGFPE handler with an extra argumentthat distinguishes various causes of the exception. In order to accessthis argument, you must define the handler to accept two arguments,which means you must cast it to a one-argument function type in order toestablish the handler. The GNU C Library does provide this extraargument, but the value is meaningful only on operating systems thatprovide the information (BSD systems and GNU systems).
FPE_INTOVF_TRAP
Integer overflow (impossible in a C program unless you enable overflowtrapping in a hardware-specific fashion).
FPE_INTDIV_TRAP
Integer division by zero.
FPE_SUBRNG_TRAP
Subscript-range (something that C programs never check for).
FPE_FLTOVF_TRAP
Floating overflow trap.
FPE_FLTDIV_TRAP
Floating/decimal division by zero.
FPE_FLTUND_TRAP
Floating underflow trap. (Trapping on floating underflow is notnormally enabled.)
FPE_DECOVF_TRAP
Decimal overflow trap. (Only a few machines have decimal arithmetic andC never uses it.)
