[lkml]   [2010]   [Feb]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    SubjectRe: [PATCH 2/2] hw-breakpoint: Keep track of dr7 local enable bits
    2010/2/19 K.Prasad <>:
    > So, the thread's copy of DR7 (in thread->ptrace_dr7) stores the
    > requested data even if the 'write' onto DR7 i.e. ptrace_write_dr7()
    > failed. This can be the other way round i.e. populate the thread's copy
    > of DR7 only if the write was successful.

    No. We store the new dr7 value only if ptrace_set_dr7() didn't fail.

    > I think it will be in consonance with the v2.6.32 behaviour as well. For
    > instance, in the code snippet from ptrace_set_debugreg() in v2.6.32
    > below:
    >                for (i = 0; i < 4; i++)
    >                        if ((DR7_MASK >> ((data >> (16 + 4*i)) & 0xf)) & 1)
    >                                return -EIO;
    >                child->thread.debugreg7 = data;
    > The thread's copy of DR7 is populated only if the incoming data is
    > found to be valid.

    This is also what does this patch. thread->ptrace_dr7 is only
    changed if ptrace_set_dr7() succeeded.

    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to
    More majordomo info at
    Please read the FAQ at

     \ /
      Last update: 2010-02-19 16:37    [W:0.031 / U:2.756 seconds]
    ©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site