From 2aa746ec0240dcbe70aef10f40fb1518f6dfb137 Mon Sep 17 00:00:00 2001 From: Justin Stitt Date: Mon, 26 Aug 2024 10:40:49 -0700 Subject: [PATCH] tracing/branch-profiler: Replace deprecated strncpy with strscpy strncpy() is deprecated for use on NUL-terminated destination strings [1] and as such we should prefer more robust and less ambiguous string interfaces. Both of these fields want to be NUL-terminated as per their use in printk: F_printk("%u:%s:%s (%u)%s", __entry->line, __entry->func, __entry->file, __entry->correct, __entry->constant ? " CONSTANT" : "") Use strscpy() as it NUL-terminates the destination buffer, so it doesn't have to be done manually. Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1] Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html Link: https://github.com/KSPP/linux/issues/90 Cc: linux-hardening@vger.kernel.org Cc: Masami Hiramatsu Cc: Mathieu Desnoyers Cc: Kees Cook Link: https://lore.kernel.org/20240826-strncpy-kernel-trace-trace_branch-c-v1-1-b2c14f2e9e84@google.com Signed-off-by: Justin Stitt Signed-off-by: Steven Rostedt (Google) --- kernel/trace/trace_branch.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/kernel/trace/trace_branch.c b/kernel/trace/trace_branch.c index e47fdb4c92fbc..aa63548873c36 100644 --- a/kernel/trace/trace_branch.c +++ b/kernel/trace/trace_branch.c @@ -74,10 +74,8 @@ probe_likely_condition(struct ftrace_likely_data *f, int val, int expect) p--; p++; - strncpy(entry->func, f->data.func, TRACE_FUNC_SIZE); - strncpy(entry->file, p, TRACE_FILE_SIZE); - entry->func[TRACE_FUNC_SIZE] = 0; - entry->file[TRACE_FILE_SIZE] = 0; + strscpy(entry->func, f->data.func); + strscpy(entry->file, p); entry->constant = f->constant; entry->line = f->data.line; entry->correct = val == expect;