[lldb-dev] software breakpoints show up in a memory read when debugging via rsp

[Greg Clayton]

Yes, if you set breakpoints via the z packets, then the GDB server should remove any breakpoint traps from any memory that is read via the memory read/write packets (m/M and x/X packets (binary memory read)).

> On Apr 22, 2015, at 3:54 PM, Ted Woodward <ted.woodward at codeaurora.org> wrote:
> 
> Expected behavior when doing a memory read or disassembly is that software breakpoints don’t show up – the original code does.
>  
> Using lldb on x86 Linux, I run a test program and set a breakpoint, then disassemble. I get this:
>  
> Process 22519 stopped
> * thread #1: tid = 22519, 0x00000000004004db test`main(argc=1, argv=0x00007fffffffea58) + 11 at test.c:3, name = 'test', stop reason = breakpoint 1.1
>     frame #0: 0x00000000004004db test`main(argc=1, argv=0x00007fffffffea58) + 11 at test.c:3
>    1    int main (int argc, void **argv)
>    2    {
> -> 3      int i = 1;
>    4      int j = 2;
>    5      int k = 3;
>    6      return 0;
>    7    }
> (lldb) dis
> test`main:
>     0x4004d0 <+0>:  pushq  %rbp
>     0x4004d1 <+1>:  movq   %rsp, %rbp
>     0x4004d4 <+4>:  movl   %edi, -0x14(%rbp)
>     0x4004d7 <+7>:  movq   %rsi, -0x20(%rbp)
> ->  0x4004db <+11>: int3  
>     0x4004dc <+12>: hlt   
>     0x4004de <+14>: addl   %eax, (%rax)
>     0x4004e0 <+16>: addb   %al, (%rax)
>  
>  
> Shouldn’t the remote gdbserver (lldb-server, in this case) replace the software breakpoint instructions with the actual opcodes?
>  
> --
> Qualcomm Innovation Center, Inc.
> The Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project
>  
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