tracing: tprobe-events: Reject invalid tracepoint name

commit d0453655b6ddc685a4837f3cc0776ae8eef62d01 upstream.

Commit 57a7e6de9e30 ("tracing/fprobe: Support raw tracepoints on
future loaded modules") allows user to set a tprobe on non-exist
tracepoint but it does not check the tracepoint name is acceptable.
So it leads tprobe has a wrong character for events (e.g. with
subsystem prefix). In this case, the event is not shown in the
events directory.

Reject such invalid tracepoint name.

The tracepoint name must consist of alphabet or digit or '_'.

Link: https://lore.kernel.org/all/174055073461.4079315.15875502830565214255.stgit@mhiramat.tok.corp.google.com/
Fixes: 57a7e6de9e30 ("tracing/fprobe: Support raw tracepoints on future loaded modules")
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/kernel/trace/trace_fprobe.c b/kernel/trace/trace_fprobe.c
index db897992c29e3c9cc5846b162f48bc1aa0c317a3..99048c330382239a117c33eafb669658f87bf03d 100644 (file)
--- a/kernel/trace/trace_fprobe.c
+++ b/kernel/trace/trace_fprobe.c
@@ -1018,6 +1018,19 @@ static int parse_symbol_and_return(int argc, const char *argv[],
        if (*is_return)
                return 0;
 
+       if (is_tracepoint) {
+               tmp = *symbol;
+               while (*tmp && (isalnum(*tmp) || *tmp == '_'))
+                       tmp++;
+               if (*tmp) {
+                       /* find a wrong character. */
+                       trace_probe_log_err(tmp - *symbol, BAD_TP_NAME);
+                       kfree(*symbol);
+                       *symbol = NULL;
+                       return -EINVAL;
+               }
+       }
+
        /* If there is $retval, this should be a return fprobe. */
        for (i = 2; i < argc; i++) {
                tmp = strstr(argv[i], "$retval");

diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h
index 5803e6a415705505578ec1ca8d0264a49956b7b5..fba3ede8705419c953e8f0e0a0c712a50acd049c 100644 (file)
--- a/kernel/trace/trace_probe.h
+++ b/kernel/trace/trace_probe.h
@@ -481,6 +481,7 @@ extern int traceprobe_define_arg_fields(struct trace_event_call *event_call,
        C(NON_UNIQ_SYMBOL,      "The symbol is not unique"),            \
        C(BAD_RETPROBE,         "Retprobe address must be an function entry"), \
        C(NO_TRACEPOINT,        "Tracepoint is not found"),             \
+       C(BAD_TP_NAME,          "Invalid character in tracepoint name"),\
        C(BAD_ADDR_SUFFIX,      "Invalid probed address suffix"), \
        C(NO_GROUP_NAME,        "Group name is not specified"),         \
        C(GROUP_TOO_LONG,       "Group name is too long"),              \