diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/trace/trace_events.c | 35 |
1 files changed, 29 insertions, 6 deletions
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index e0449e648871..714285e23a2e 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -401,6 +401,31 @@ static bool process_string(const char *fmt, int len, struct trace_event_call *ca return true; } +static void test_double_dereference(const char *str, int len, + struct trace_event_call *call) +{ + const char *ptr; + const char *end = str + len; + + ptr = strstr(str, "REC->"); + + while (ptr && ptr < end) { + + ptr += 5; + for (; ptr < end; ptr++) { + if (ptr[0] == '-' && ptr[1] == '>') { + WARN_ONCE(1, "Event %s has double dereference in TP_printk: %.*s\n", + trace_event_name(call), len, str); + return; + } + if (!isalnum(*ptr) && *ptr != '_') + break; + } + + ptr = strstr(ptr, "REC->"); + } +} + static void handle_dereference_arg(const char *arg_str, u64 string_flags, int len, u64 *dereference_flags, int arg, struct trace_event_call *call) @@ -460,12 +485,6 @@ static void test_event_printk(struct trace_event_call *call) if (in_quote) { arg = 0; first = false; - /* - * If there was no %p* uses - * the fmt is OK. - */ - if (!dereference_flags) - return; } } if (in_quote) { @@ -577,6 +596,8 @@ static void test_event_printk(struct trace_event_call *call) continue; } + test_double_dereference(fmt + start_arg, e - start_arg, call); + if (dereference_flags & (1ULL << arg)) { handle_dereference_arg(fmt + start_arg, string_flags, e - start_arg, @@ -590,6 +611,8 @@ static void test_event_printk(struct trace_event_call *call) } } + test_double_dereference(fmt + start_arg, i - start_arg, call); + if (dereference_flags & (1ULL << arg)) { handle_dereference_arg(fmt + start_arg, string_flags, i - start_arg, |