From: Fredrik_Oestman@mentor.com (Oestman, Fredrik)
Subject: [lttng-dev] UST check pointer/de-reference order
Date: Tue, 5 Jun 2012 08:19:29 +0000 [thread overview]
Message-ID: <524C960C5DFC794E82BE548D825F05CF28344978@EU-MBX-01.mgc.mentorg.com> (raw)
In-Reply-To: <524C960C5DFC794E82BE548D825F05CF28344927@EU-MBX-01.mgc.mentorg.com>
I stumbled across some code where pointers are de-referenced and then checked for NULL.
Cheers,
Fredrik ?stman
diff --git a/liblttng-ust-ctl/ustctl.c b/liblttng-ust-ctl/ustctl.c
index 9789413..80aed04 100644
--- a/liblttng-ust-ctl/ustctl.c
+++ b/liblttng-ust-ctl/ustctl.c
@@ -732,7 +732,7 @@ 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;
@@ -741,6 +741,7 @@ 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)
@@ -784,11 +785,12 @@ 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;
@@ -805,11 +807,12 @@ 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;
}
@@ -823,12 +826,13 @@ 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,
@@ -841,11 +845,12 @@ 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;
@@ -855,11 +860,12 @@ 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);
next prev parent reply other threads:[~2012-06-05 8:19 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CABnnsm_MJHGq_TcjZj5_4_2TmTDhQUPGeJAyd3HYn6V7bPFQaw@mail.gmail.com>
[not found] ` <524C960C5DFC794E82BE548D825F05CF283435F8@EU-MBX-01.mgc.mentorg.com>
2012-06-04 3:22 ` [lttng-dev] Displaying graphical results tchak adim
2012-06-04 20:57 ` tchak adim
2012-06-05 7:06 ` Oestman, Fredrik
2012-06-05 8:19 ` Oestman, Fredrik [this message]
2012-06-05 15:19 ` [lttng-dev] UST check pointer/de-reference order Mathieu Desnoyers
2012-06-05 9:27 ` [lttng-dev] Displaying graphical results Francis Giraldeau
2012-06-05 13:40 ` Bernd Hufmann
2012-06-05 16:56 ` tchak adim
[not found] ` <4FC3CBF6.1060608@polymtl.ca>
2012-06-05 17:02 ` Brosseau, Yannick
2012-06-05 17:12 ` tchak adim
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