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| author | Daniel Stone <daniels@collabora.com> | 2016-02-08 22:12:58 +0100 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2016-02-11 10:42:09 +0100 |
| commit | 8e7199c2c50fff1969302643171eaa33f1ca148f (patch) | |
| tree | 1eda919447d1599037fc2216ea27682f05953df4 /drivers | |
| parent | component: Detach components when deleting master struct (diff) | |
| download | linux-8e7199c2c50fff1969302643171eaa33f1ca148f.tar.xz linux-8e7199c2c50fff1969302643171eaa33f1ca148f.zip | |
component: remove device from master match list on failed add
Calling component_add() may result in the completion of a set of
devices, which will try to bring up a master. In bringing the master
up, we populate its match array with the current set of children.
If binding any of the devices fails, component_add() itself will fail,
free the struct component entry, and return to the caller. The
now-freed entry is never removed from the master's match array, and
will later be used in a futile attempt to bind to freed memory.
Bring component_add's behaviour on failure to bring up a master into
line with component_del by removing the (to-be-freed) component from
the master's match array.
The specific case which broke was:
- rockchip_drm_drv adds a component master
- dwhdmi_rockchip adds a child component in probe (master incomplete)
- rockchip_drm_vop adds two children in probe, which completes the
set
- inside component_add, we try to bring up the master, having
populated the master's match array, and fail with EPROBE_DEFER from
dwhdmi_rockchip; we delete the putative component
- rockchip_drm_vop's probe fails and returns EPROBE_DEFER
- we later re-probe rockchip_drm_vop and add the component; the
master is complete, so we attempt to bring it up again
- walking the match array, we find the previous child, whose master
pointer doesn't match (as it has been freed in the meantime)
- rockchip_drm_vop probe fails, and will never be attempted again
Fixes: ffc30b74fd6d01588bd3fdebc3b1acc0857e6fc8
Signed-off-by: Daniel Stone <daniels@collabora.com>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Thierry Reding <treding@nvidia.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/base/component.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/base/component.c b/drivers/base/component.c index 2738039aae9e..04a1582e80bb 100644 --- a/drivers/base/component.c +++ b/drivers/base/component.c @@ -491,6 +491,8 @@ int component_add(struct device *dev, const struct component_ops *ops) ret = try_to_bring_up_masters(component); if (ret < 0) { + if (component->master) + remove_component(component->master, component); list_del(&component->node); kfree(component); |