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 Signed-off-by: Salvatore Mesoraca <s.mesorac...@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); -- 1.9.1
