From 1d84e8e7060f36b78cacc7a32d8e30522d62e90b 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 aa16475d..ed7072cf 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. */ @@ -500,7 +502,7 @@ static void __event_probe__##_name(void *__data); max_t(size_t, lttng_strlen_user_inatomic(_src), 1); \ } else { \ __event_len += this_cpu_ptr(<tng_dynamic_len_stack)->stack[this_cpu_ptr(<tng_dynamic_len_stack)->offset - 1] = \ - strlen(_src) + 1; \ + strlen((_src) ? (_src) : __LTTNG_NULL_STRING) + 1; \ } #undef _ctf_enum @@ -713,7 +715,8 @@ error: \ #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 *); \ } @@ -1024,12 +1027,16 @@ 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