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    SubjectRe: [PATCH 4/5] sh: ftrace: fix the comments for ftrace_modify_code
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    Hello.

    On 12/4/2015 10:27 AM, Li Bin wrote:

    > There is no need to worry about module and __init text disappearing
    > case, because that ftrace has a module notifier that is called when
    > a module is being unloaded and before the text goes away and this
    > code grabs the ftrace_lock mutex and removes the module functions
    > from the ftrace list, such that it will no longer do any
    > modifications to that module's text, the update to make functions
    > be traced or not is done under the ftrace_lock mutex as well.
    > And by now, __init section codes should not been modified
    > by ftrace, because it is black listed in recordmcount.c and
    > ignored by ftrace.
    >
    > Cc: linux-sh@vger.kernel.org
    > Suggested-by: Steven Rostedt <rostedt@goodmis.org>
    > Signed-off-by: Li Bin <huawei.libin@huawei.com>
    > ---
    > arch/sh/kernel/ftrace.c | 13 ++++++-------
    > 1 files changed, 6 insertions(+), 7 deletions(-)
    >
    > diff --git a/arch/sh/kernel/ftrace.c b/arch/sh/kernel/ftrace.c
    > index 079d70e..b696f92 100644
    > --- a/arch/sh/kernel/ftrace.c
    > +++ b/arch/sh/kernel/ftrace.c
    > @@ -212,13 +212,12 @@ static int ftrace_modify_code(unsigned long ip, unsigned char *old_code,
    > unsigned char replaced[MCOUNT_INSN_SIZE];
    >
    > /*
    > - * Note: Due to modules and __init, code can
    > - * disappear and change, we need to protect against faulting
    > - * as well as code changing. We do this by using the
    > - * probe_kernel_* functions.
    > - *
    > - * No real locking needed, this code is run through
    > - * kstop_machine, or before SMP starts.
    > + * Note:
    > + * We are paranoid about modifying text, as if a bug were to happen, it

    s/were/was/.

    [...]

    MBR, Sergei



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