Re: [RFA] Fix hw watchpoints in process record.

[Michael Snyder <msnyder@vmware.com>]

Hui Zhu wrote:
> I think this patch still not OK.
> 
> (gdb) start
> Temporary breakpoint 1 at 0x400554: file 1.c, line 20.
> Starting program: /home/teawater/gdb/bgdbno/gdb/a.out
> 
> Temporary breakpoint 1, main () at 1.c:20
> 20	       int     b = 0;
> (gdb) disas
> Dump of assembler code for function main:
>    0x000000000040054c <+0>:	push   %rbp
>    0x000000000040054d <+1>:	mov    %rsp,%rbp
>    0x0000000000400550 <+4>:	sub    $0x10,%rsp
> => 0x0000000000400554 <+8>:	movl   $0x0,-0x4(%rbp)
>    0x000000000040055b <+15>:	movl   $0x1,-0x8(%rbp)
>    0x0000000000400562 <+22>:	mov    0x200ac8(%rip),%esi        # 0x601030 <a>
>    0x0000000000400568 <+28>:	mov    -0x8(%rbp),%ecx
>    0x000000000040056b <+31>:	mov    -0x4(%rbp),%edx
>    0x000000000040056e <+34>:	mov    $0x4006f4,%edi
>    0x0000000000400573 <+39>:	mov    $0x0,%eax
>    0x0000000000400578 <+44>:	callq  0x4003f8 <printf@plt>
>    0x000000000040057d <+49>:	mov    $0x0,%eax
>    0x0000000000400582 <+54>:	callq  0x400527 <cool>
>    0x0000000000400587 <+59>:	mov    %eax,-0x4(%rbp)
>    0x000000000040058a <+62>:	mov    0x200aa0(%rip),%esi        # 0x601030 <a>
>    0x0000000000400590 <+68>:	mov    -0x8(%rbp),%ecx
>    0x0000000000400593 <+71>:	mov    -0x4(%rbp),%edx
>    0x0000000000400596 <+74>:	mov    $0x4006f4,%edi
>    0x000000000040059b <+79>:	mov    $0x0,%eax
>    0x00000000004005a0 <+84>:	callq  0x4003f8 <printf@plt>
>    0x00000000004005a5 <+89>:	addl   $0x1,-0x8(%rbp)
>    0x00000000004005a9 <+93>:	mov    0x200a81(%rip),%esi        # 0x601030 <a>
>    0x00000000004005af <+99>:	mov    -0x8(%rbp),%ecx
>    0x00000000004005b2 <+102>:	mov    -0x4(%rbp),%edx
>    0x00000000004005b5 <+105>:	mov    $0x4006f4,%edi
>    0x00000000004005ba <+110>:	mov    $0x0,%eax
>    0x00000000004005bf <+115>:	callq  0x4003f8 <printf@plt>
>    0x00000000004005c4 <+120>:	mov    0x200a66(%rip),%eax        # 0x601030 <a>
>    0x00000000004005ca <+126>:	sub    $0x2,%eax
>    0x00000000004005cd <+129>:	mov    %eax,0x200a5d(%rip)        # 0x601030 <a>
>    0x00000000004005d3 <+135>:	mov    0x200a57(%rip),%esi        # 0x601030 <a>
>    0x00000000004005d9 <+141>:	mov    -0x8(%rbp),%ecx
>    0x00000000004005dc <+144>:	mov    -0x4(%rbp),%edx
>    0x00000000004005df <+147>:	mov    $0x4006f4,%edi
> ---Type <return> to continue, or q <return> to quit---q
> Quit
> (gdb) hb *0x000000000040055b
> During symbol reading, incomplete CFI data; unspecified registers
> (e.g., rax) at 0x400550.
> Hardware assisted breakpoint 2 at 0x40055b: file 1.c, line 21.
> (gdb) record
> (gdb) c
> Continuing.
> 
> Program received signal SIGTRAP, Trace/breakpoint trap.
> 0x000000000040055c in main () at 1.c:21
> 21	       int     c = 1;
> (gdb) info reg pc
> pc: 0x40055c
> 
> 
> The stop pc is not right.  Looks we need do some special works when
> this is a simple hb.

Ouch, yeah, that looks like a decr_pc_after_break issue maybe?


> On Sun, Nov 22, 2009 at 03:46, Michael Snyder <msnyder@vmware.com> wrote:
>> Hui Zhu wrote:
>>> Hi guys,
>>>
>>> There are some patches about hw breakpoint are running on maillist.
>>> If you don't mind, I suggest we wait until they OK.
>> I don't think there are any conflicts...
>>