yes ,you are correct :) seems like the debug registers are being set correctly(i have checked it and debugged it ),but still the breakpoint does not break.... i have done a special testing ,i can tell you that if you will write the memory address directly --- it will break. but if you write the memory address indirectly ---- it will not break !!!
Jay Lan wrote: > Avi Nehori wrote: > >> Jay, >> try to set an hardware breakpoint to a global variable and then modify it . >> the system will not drop into kdb in this case. >> > > Hi Avi, > > I reprodued the problem. KDB hardware breakpoint is triggered on > access to a function, but not on value changes to a global variable. > It would be nice, isn't it? Hmmm... > > - jay > > >> Jay Lan wrote: >> >>> Avi Nehori wrote: >>> >>> >>>> Jay, >>>> the patch didnt work for me. >>>> I'm still looking for a resolution... >>>> >>>> >>> Hmmm, i just tested with Konstantin's patch on 2.6.25 and >>> 2.6.26-rc3, and it seemed to work for me. >>> >>> >>> >>> >>>> Entering kdb (current=0xf7841c80, pid 0) on processor 1 due to Keyboard >>>> Entry >>>> >>>> >>> [1]kdb> bpha do_sync >>> Forced Instruction(Register) BP #0 at 0xc017b6a4 (do_sync) >>> is enabled in dr0 globally >>> [1]kdb> go >>> >>> I set up a global hardware breakpoint at do_sync here. >>> Then i entered 'sync' command from a shell. The system dropped into KDB: >>> >>> Instruction(Register) breakpoint #0 at 0xc017b6a4 >>> 0xc017b6a4 do_sync: push %ebx >>> >>> Entering kdb (0xf72a23a0, pid 5473) on processor 2 due to Debug @ 0xc017b6a4 >>> [2]kdb> >>> >>> You are testing a 2.4.21 kernel... I do not know if KDB support i386 >>> in 2.4.21 at all. >>> >>> Keith Owens did a tremendous job in making KDB backtrace working on >>> x86_64/i386 and fixed other bugs along the way, but his work did not >>> complete until 2.6.23. My brief effort of back porting the x86_64/i386 >>> KDB support to sles10sp2 (2.6.16 based) and rhel5.2 (2.6.18 based) >>> did not work well. So, honestly, i recommand you move up to 2.6.23 >>> or later. >>> >>> Thanks, >>> - jay >>> >>> >>> >>>> Jay Lan wrote: >>>> >>>> >>>>> Hi Avi, >>>>> >>>>> Did Konstantin's patch work for you? His patch caused ia64 >>>>> compilation to fail, but i would like to know if his patch >>>>> work for you on i386. >>>>> >>>>> Thanks! >>>>> >>>>> - jay >>>>> >>>>> >>>>> Scanned by Check Point Total Security Gateway. >>>>> >>>>> >>>>> >>>>> >>>> --------------------------- >>>> Use http://oss.sgi.com/ecartis to modify your settings or to unsubscribe. >>>> >>>> >>> Scanned by Check Point Total Security Gateway. >>> >>> >>> >> --------------------------- >> Use http://oss.sgi.com/ecartis to modify your settings or to unsubscribe. >> > > > Scanned by Check Point Total Security Gateway. > > --------------------------- Use http://oss.sgi.com/ecartis to modify your settings or to unsubscribe.
