Re: i386 ddb trace stopped working with gcc48

["J. Hannken-Illjes" <hannken%eis.cs.tu-bs.de@localhost>]

On 21 Apr 2014, at 19:34, Christos Zoulas <christos%astron.com@localhost> wrote:

> In article <910F0BED-9FD7-4C06-B886-E91002D034C3%eis.cs.tu-bs.de@localhost>,
> J. Hannken-Illjes <hannken%eis.cs.tu-bs.de@localhost> wrote:
>> On 21 Apr 2014, at 14:39, J. Hannken-Illjes 
>> <hannken%eis.cs.tu-bs.de@localhost> wrote:
>> 
>>> Since i386 switched to gcc48 ddb trace no longer works:
>>> 
>>> fatal breakpoint trap in supervisor mode
>>> trap type 1 code 0 eip c02802f4 cs 8 eflags 202 cr2 bbbab0c4 ilevel 8 esp 
>>> 800
>>> curlwp 0xc5a9fd20 pid 0 lid 2 lowest kstack 0xdd3b22c0
>>> Stopped in pid 0.2 (system) at  netbsd:breakpoint+0x4:  popl    %ebp
>>> db{0}> bt
>>> 
>> breakpoint(c0e661c0,3f8,0,0,c61c5158,c170dacc,c6188000,c5f396c0,c5f39748,dd3b4edc)
>>  at netbsd:breakpoint+0x4
>>> 
>>> Thats all, never get more than one line.
>>> The i386_frame from %ebp = dd25ef30 looks like:
>>> 
>>> dd25ef30:       7ff         <= should be the previous frame
>>> dd25ef34:       c0277cc1    <= comintr+0x53e (caller of breakpoint)
>>> dd25ef38:       c0e661c0
>>> 
>>> Ideas anyone?
>> 
>> Some further notes:
>> 
>> - The function prologue has changed as
>> 
>>      -push   %ebp
>>      -mov    %esp,%ebp
>>       sub    $0x14,%esp
>> 
>>       call   ...
>>      -leave  
>>      +add    $0x14,%esp
>>       ret    
>> 
>> - With -fno-omit-frame-pointer all is well.
> 
> Perhaps the default changes to -fomit-frame-pointer... We should consider
> changing it back like we did for amd64.

Do we really want to add

  makeoptions "COPTS="... -fno-omit-frame-pointer"

to all i386 kernel configs like amd64 does or should it better
go to sys/arch/i386/conf/Makefile.i386?

--
J. Hannken-Illjes - hannken%eis.cs.tu-bs.de@localhost - TU Braunschweig 
(Germany)