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authorGeert Uytterhoeven <geert+renesas@glider.be>2017-12-05 16:27:03 +0100
committerRob Herring <robh@kernel.org>2017-12-06 16:08:30 -0600
commit5e4748175fe942c86cbab840e2fa41a92b4d6cf6 (patch)
tree09efbc32025fa3cf552b30155a9309fc5785fb78
parent1352f09b4cc4f9dce386620b118401738bbf0d5f (diff)
downloadlinux-stericsson-5e4748175fe942c86cbab840e2fa41a92b4d6cf6.tar.gz
of: overlay: Fix (un)locking in of_overlay_apply()
The special overlay mutex is taken first, hence it should be released last in the error path. of_resolve_phandles() must be called with of_mutex held. Without it, a node and new phandle could be added via of_attach_node(), making the max phandle wrong. free_overlay_changeset() must be called with of_mutex held, if any non-trivial cleanup is to be done. Hence move "mutex_lock(&of_mutex)" up, as suggested by Frank, and merge the two tail statements of the success and error paths, now they became identical. Note that while the two mutexes are adjacent, we still need both: __of_changeset_apply_notify(), which is called by __of_changeset_apply() unlocks of_mutex, then does notifications then locks of_mutex. So the mutex get released in the middle of of_overlay_apply() Fixes: f948d6d8b792bb90 ("of: overlay: avoid race condition between applying multiple overlays") Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Frank Rowand <frank.rowand@sony.com> Signed-off-by: Rob Herring <robh@kernel.org>
-rw-r--r--drivers/of/overlay.c15
1 files changed, 5 insertions, 10 deletions
diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c
index bb3f123ed259..fcce5cdbe229 100644
--- a/drivers/of/overlay.c
+++ b/drivers/of/overlay.c
@@ -706,12 +706,11 @@ int of_overlay_apply(struct device_node *tree, int *ovcs_id)
}
of_overlay_mutex_lock();
+ mutex_lock(&of_mutex);
ret = of_resolve_phandles(tree);
if (ret)
- goto err_overlay_unlock;
-
- mutex_lock(&of_mutex);
+ goto err_free_overlay_changeset;
ret = init_overlay_changeset(ovcs, tree);
if (ret)
@@ -754,18 +753,14 @@ int of_overlay_apply(struct device_node *tree, int *ovcs_id)
ret = ret_tmp;
}
- mutex_unlock(&of_mutex);
- of_overlay_mutex_unlock();
-
- goto out;
-
-err_overlay_unlock:
- of_overlay_mutex_unlock();
+ goto out_unlock;
err_free_overlay_changeset:
free_overlay_changeset(ovcs);
+out_unlock:
mutex_unlock(&of_mutex);
+ of_overlay_mutex_unlock();
out:
pr_debug("%s() err=%d\n", __func__, ret);