From 98e38a6025ad151a5c05a62b82cbac7c192efcaa Mon Sep 17 00:00:00 2001 From: Mathieu Desnoyers Date: Mon, 16 May 2016 16:45:24 -0400 Subject: [PATCH] Fix: ctf_string() should handle NULL pointers The regmap instrumentation can send a NULL string (e.g. on ARM32). Signed-off-by: Mathieu Desnoyers --- probes/lttng-tracepoint-event-impl.h | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/probes/lttng-tracepoint-event-impl.h b/probes/lttng-tracepoint-event-impl.h index ba906ac4..45c38ff4 100644 --- a/probes/lttng-tracepoint-event-impl.h +++ b/probes/lttng-tracepoint-event-impl.h @@ -35,6 +35,8 @@ #include #include +#define __LTTNG_NULL_STRING "(null)" + /* * Macro declarations used for all stages. */ @@ -392,7 +394,7 @@ static void __event_probe__##_name(void *__data); max_t(size_t, lttng_strlen_user_inatomic(_src), 1); \ else \ __event_len += __dynamic_len[__dynamic_len_idx++] = \ - strlen(_src) + 1; + strlen((_src) ? (_src) : __LTTNG_NULL_STRING) + 1; #undef TP_PROTO #define TP_PROTO(...) __VA_ARGS__ @@ -581,7 +583,8 @@ static inline size_t __event_get_size__##_name(size_t *__dynamic_len, \ #undef _ctf_string #define _ctf_string(_item, _src, _user, _nowrite) \ { \ - const void *__ctf_tmp_ptr = (_src); \ + const void *__ctf_tmp_ptr = \ + ((_src) ? (_src) : __LTTNG_NULL_STRING); \ memcpy(__stack_data, &__ctf_tmp_ptr, sizeof(void *)); \ __stack_data += sizeof(void *); \ } @@ -871,12 +874,16 @@ static inline size_t __event_get_align__##_name(void *__tp_locvar) \ #undef _ctf_string #define _ctf_string(_item, _src, _user, _nowrite) \ - lib_ring_buffer_align_ctx(&__ctx, lttng_alignof(*(_src))); \ if (_user) { \ + lib_ring_buffer_align_ctx(&__ctx, lttng_alignof(*(_src))); \ __chan->ops->event_strcpy_from_user(&__ctx, _src, \ __get_dynamic_len(dest)); \ } else { \ - __chan->ops->event_strcpy(&__ctx, _src, \ + const char *__ctf_tmp_string = \ + ((_src) ? (_src) : __LTTNG_NULL_STRING); \ + lib_ring_buffer_align_ctx(&__ctx, \ + lttng_alignof(*__ctf_tmp_string)); \ + __chan->ops->event_strcpy(&__ctx, __ctf_tmp_string, \ __get_dynamic_len(dest)); \ } -- 2.34.1