Messages in this thread | | | Date | Fri, 30 Mar 2018 10:34:11 -0400 | From | Steven Rostedt <> | Subject | Re: [v2] ftrace: drop a VLA in module_exists() |
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On Fri, 30 Mar 2018 10:53:08 +0200 Salvatore Mesoraca <s.mesoraca16@gmail.com> wrote:
Couple of things. First, "PATCH" was dropped from the subject. If my inbox was busy today, I probably would have missed this email.
> Avoid a VLA[1] by using a real constant expression instead of a variable. > The compiler should be able to optimize the original code and avoid using > an actual VLA. Anyway this change is useful because it will avoid a false > positive with -Wvla, it might also help the compiler generating better > code. > > [1] https://lkml.org/lkml/2018/3/7/621
Second, do not use lkml.org, use http://lkml.kernel.org/r/<messageid>
Search for "Link:" tags in git log to see examples.
Other than that, the patch looks fine to me and I can pull it for the next merge window.
-- Steve
> > Signed-off-by: Salvatore Mesoraca <s.mesoraca16@gmail.com> > --- > kernel/trace/ftrace.c | 7 +++---- > 1 file changed, 3 insertions(+), 4 deletions(-) > > diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c > index eac9ce2..16bbf06 100644 > --- a/kernel/trace/ftrace.c > +++ b/kernel/trace/ftrace.c > @@ -3902,14 +3902,13 @@ static bool module_exists(const char *module) > { > /* All modules have the symbol __this_module */ > const char this_mod[] = "__this_module"; > - const int modname_size = MAX_PARAM_PREFIX_LEN + sizeof(this_mod) + 1; > - char modname[modname_size + 1]; > + char modname[MAX_PARAM_PREFIX_LEN + sizeof(this_mod) + 2]; > unsigned long val; > int n; > > - n = snprintf(modname, modname_size + 1, "%s:%s", module, this_mod); > + n = snprintf(modname, sizeof(modname), "%s:%s", module, this_mod); > > - if (n > modname_size) > + if (n > sizeof(modname) - 1) > return false; > > val = module_kallsyms_lookup_name(modname);
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