• Jason Wessel's avatar
    x86,kgdb: Fix DEBUG_RODATA limitation using text_poke() · 3751d3e8
    Jason Wessel authored
    There has long been a limitation using software breakpoints with a
    kernel compiled with CONFIG_DEBUG_RODATA going back to 2.6.26. For
    this particular patch, it will apply cleanly and has been tested all
    the way back to 2.6.36.
    
    The kprobes code uses the text_poke() function which accommodates
    writing a breakpoint into a read-only page.  The x86 kgdb code can
    solve the problem similarly by overriding the default breakpoint
    set/remove routines and using text_poke() directly.
    
    The x86 kgdb code will first attempt to use the traditional
    probe_kernel_write(), and next try using a the text_poke() function.
    The break point install method is tracked such that the correct break
    point removal routine will get called later on.
    
    Cc: x86@kernel.org
    Cc: Thomas Gleixner <tglx@linutronix.de>
    Cc: Ingo Molnar <mingo@redhat.com>
    Cc: H. Peter Anvin <hpa@zytor.com>
    Cc: stable@vger.kernel.org # >= 2.6.36
    Inspried-by: default avatarMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
    Signed-off-by: default avatarJason Wessel <jason.wessel@windriver.com>
    3751d3e8
kgdb.h 10.2 KB