问题
I am trying to debug a segmentation fault in my assembly code. Here is the GDB output
Program received signal SIGSEGV, Segmentation fault.
0x0000000000424c50 in restore_context()
(gdb) disassemble restore_context
Dump of assembler code for function restore_context:
0x0000000000424c44 <+0>: mov 0x8(%rsp),%rax
0x0000000000424c49 <+5>: mov 0x38(%rax),%rsp
0x0000000000424c4d <+9>: mov (%rax),%rdx
=>0x0000000000424c50 <+12>: mov %rdx,(%rsp)
0x0000000000424c54 <+16>: mov 0x18(%rax),%rbx
0x0000000000424c58 <+20>: mov 0x20(%rax),%rsi
0x0000000000424c5c <+24>: mov 0x28(%rax),%rdi
0x0000000000424c60 <+28>: mov 0x30(%rax),%rbp
0x0000000000424c64 <+32>: xor %rax,%rax
0x0000000000424c67 <+35>: retq
End of assembler dump.
By the little research I did , this looks like a over flow error. Can someone tell me how to debug this ? How to find this memory leak. Do we have some tool to inspect this or is their an error with my assembly code. Need help debugging this.
Here is the assembly code as well
.align 4,0x90
.global restore_context
.type restore_context,@function
restore_context:
mov 8(%rsp),%rax
mov 56(%rax), %rsp
mov 0(%rax),%rdx /* Fetch our return address */
mov %rdx, 0(%rsp) /* Save our return address */ // overflow
mov 24(%rax),%rbx
mov 32(%rax), %rsi
mov 40(%rax), %rdi
mov 48(%rax), %rbp
xor %rax,%rax
ret
This is the counterpart store_context()
.align 4,0x90
.global store_context
.type store_context,@function
store_context:
mov 8(%rsp),%rax
mov %rbx, 24(%rax)
mov %rsi, 32(%rax)
mov %rdi, 40(%rax)
mov %rbp, 48(%rax)
mov %rsp, 56(%rax)
mov 0(%rsp), %rdx
mov %rdx, 0(%rax)
xor %rax,%rax
inc %rax
ret
来源：https://stackoverflow.com/questions/23661652/segmentation-fault-in-assembly-code-c