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| author | Salvatore Mesoraca <s.mesoraca16@gmail.com> | 2018-03-30 10:53:08 +0200 |
|---|---|---|
| committer | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2018-04-06 14:56:48 +0200 |
| commit | 419e9fe53b7941481941984ce271b0ce946c3914 (patch) | |
| tree | 01122e232159dcb976ca8f06d51d74d408492728 | |
| parent | tracing: Mention trace_clock=global when warning about unstable clocks (diff) | |
| download | linux-419e9fe53b7941481941984ce271b0ce946c3914.tar.xz linux-419e9fe53b7941481941984ce271b0ce946c3914.zip | |
ftrace: Drop a VLA in module_exists()
Avoid a VLA 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.
Link: http://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@mail.gmail.com
Link: http://lkml.kernel.org/r/1522399988-8815-1-git-send-email-s.mesoraca16@gmail.com
Signed-off-by: Salvatore Mesoraca <s.mesoraca16@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
| -rw-r--r-- | kernel/trace/ftrace.c | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index eac9ce2c57a2..16bbf062018f 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); |