From 36860b656f3e4fb634d0eef500539930ca389c09 Mon Sep 17 00:00:00 2001 From: Fredrik Oestman Date: Tue, 5 Jun 2012 11:21:36 -0400 Subject: [PATCH] UST check pointer/de-reference order I stumbled across some code where pointers are de-referenced and then checked for NULL. Signed-off-by: Mathieu Desnoyers --- liblttng-ust-ctl/ustctl.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) diff --git a/liblttng-ust-ctl/ustctl.c b/liblttng-ust-ctl/ustctl.c index e4a29f99..cf7cf87a 100644 --- a/liblttng-ust-ctl/ustctl.c +++ b/liblttng-ust-ctl/ustctl.c @@ -682,7 +682,7 @@ void ustctl_unmap_channel(struct lttng_ust_shm_handle *handle) struct lttng_ust_lib_ring_buffer *ustctl_open_stream_read(struct lttng_ust_shm_handle *handle, int cpu) { - struct channel *chan = handle->shadow_chan; + struct channel *chan; int *shm_fd, *wait_fd; uint64_t *memory_map_size; struct lttng_ust_lib_ring_buffer *buf; @@ -691,6 +691,7 @@ struct lttng_ust_lib_ring_buffer *ustctl_open_stream_read(struct lttng_ust_shm_h if (!handle) return NULL; + chan = handle->shadow_chan; buf = channel_get_ring_buffer(&chan->backend.config, chan, cpu, handle, &shm_fd, &wait_fd, &memory_map_size); if (!buf) @@ -734,11 +735,12 @@ int ustctl_get_mmap_len(struct lttng_ust_shm_handle *handle, unsigned long *len) { unsigned long mmap_buf_len; - struct channel *chan = handle->shadow_chan; + struct channel *chan; if (!handle || !buf || !len) return -EINVAL; + chan = handle->shadow_chan; if (chan->backend.config.output != RING_BUFFER_MMAP) return -EINVAL; mmap_buf_len = chan->backend.buf_size; @@ -755,11 +757,12 @@ int ustctl_get_max_subbuf_size(struct lttng_ust_shm_handle *handle, struct lttng_ust_lib_ring_buffer *buf, unsigned long *len) { - struct channel *chan = handle->shadow_chan; + struct channel *chan; if (!handle || !buf || !len) return -EINVAL; + chan = handle->shadow_chan; *len = chan->backend.subbuf_size; return 0; } @@ -773,12 +776,13 @@ int ustctl_get_max_subbuf_size(struct lttng_ust_shm_handle *handle, int ustctl_get_mmap_read_offset(struct lttng_ust_shm_handle *handle, struct lttng_ust_lib_ring_buffer *buf, unsigned long *off) { - struct channel *chan = handle->shadow_chan; + struct channel *chan; unsigned long sb_bindex; if (!handle || !buf || !off) return -EINVAL; + chan = handle->shadow_chan; if (chan->backend.config.output != RING_BUFFER_MMAP) return -EINVAL; sb_bindex = subbuffer_id_get_index(&chan->backend.config, @@ -791,11 +795,12 @@ int ustctl_get_mmap_read_offset(struct lttng_ust_shm_handle *handle, int ustctl_get_subbuf_size(struct lttng_ust_shm_handle *handle, struct lttng_ust_lib_ring_buffer *buf, unsigned long *len) { - struct channel *chan = handle->shadow_chan; + struct channel *chan; if (!handle || !buf || !len) return -EINVAL; + chan = handle->shadow_chan; *len = lib_ring_buffer_get_read_data_size(&chan->backend.config, buf, handle); return 0; @@ -805,11 +810,12 @@ int ustctl_get_subbuf_size(struct lttng_ust_shm_handle *handle, int ustctl_get_padded_subbuf_size(struct lttng_ust_shm_handle *handle, struct lttng_ust_lib_ring_buffer *buf, unsigned long *len) { - struct channel *chan = handle->shadow_chan; + struct channel *chan; if (!handle || !buf || !len) return -EINVAL; + chan = handle->shadow_chan; *len = lib_ring_buffer_get_read_data_size(&chan->backend.config, buf, handle); *len = PAGE_ALIGN(*len); -- 2.34.1