diff options
| author | Daniel Vetter <daniel.vetter@ffwll.ch> | 2015-10-02 13:01:02 +0200 |
|---|---|---|
| committer | Daniel Vetter <daniel.vetter@ffwll.ch> | 2015-11-24 11:47:47 +0100 |
| commit | a48a62bc9226e731e2284afb1c782869a413e1b2 (patch) | |
| tree | d56b382176f5423b552a711016430893abf76fe1 /drivers/gpu/drm/drm_sysfs.c | |
| parent | f980a71a2ba85ba5e60b72255df1ce6722932e0e (diff) | |
| download | lwn-a48a62bc9226e731e2284afb1c782869a413e1b2.tar.gz lwn-a48a62bc9226e731e2284afb1c782869a413e1b2.zip | |
drm/sysfs: Grab lock for edid/modes_show
We chase pointers/lists without taking the locks protecting them,
which isn't that good.
Fix it.
v2: Actually unlock properly, spotted by Julia.
v3: Put the label _before_ the mutex_unlock (Emil)
Cc: Emil Velikov <emil.l.velikov@gmail.com>
Cc: Julia Lawall <julia.lawall@lip6.fr>
Link: http://patchwork.freedesktop.org/patch/msgid/1443783662-23066-1-git-send-email-daniel.vetter@ffwll.ch
Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Diffstat (limited to 'drivers/gpu/drm/drm_sysfs.c')
| -rw-r--r-- | drivers/gpu/drm/drm_sysfs.c | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/drivers/gpu/drm/drm_sysfs.c b/drivers/gpu/drm/drm_sysfs.c index 615b7e667320..c75f02297d01 100644 --- a/drivers/gpu/drm/drm_sysfs.c +++ b/drivers/gpu/drm/drm_sysfs.c @@ -256,23 +256,29 @@ static ssize_t edid_show(struct file *filp, struct kobject *kobj, struct drm_connector *connector = to_drm_connector(connector_dev); unsigned char *edid; size_t size; + ssize_t ret = 0; + mutex_lock(&connector->dev->mode_config.mutex); if (!connector->edid_blob_ptr) - return 0; + goto unlock; edid = connector->edid_blob_ptr->data; size = connector->edid_blob_ptr->length; if (!edid) - return 0; + goto unlock; if (off >= size) - return 0; + goto unlock; if (off + count > size) count = size - off; memcpy(buf, edid + off, count); - return count; + ret = count; +unlock: + mutex_unlock(&connector->dev->mode_config.mutex); + + return ret; } static ssize_t modes_show(struct device *device, @@ -283,10 +289,12 @@ static ssize_t modes_show(struct device *device, struct drm_display_mode *mode; int written = 0; + mutex_lock(&connector->dev->mode_config.mutex); list_for_each_entry(mode, &connector->modes, head) { written += snprintf(buf + written, PAGE_SIZE - written, "%s\n", mode->name); } + mutex_unlock(&connector->dev->mode_config.mutex); return written; } |