This patch addresses several related memory management issues in the probe function:
1. for_each_available_child_of_node performs an of_node_get on each iteration, so a break out of the loop requires an of_node_put. A simplified version of the semantic patch that fixes this problem is as follows (http://coccinelle.lip6.fr): // <smpl> @@ expression root,e; local idexpression child; @@ for_each_available_child_of_node(root, child) { ... when != of_node_put(child) when != e = child ( return child; | + of_node_put(child); ? return ...; ) ... } // </smpl> 2. The devm_kzalloc'd data is not used if brcmnand_init_cs fails. Free it immediately, using devm_kfree in this case, instead of waiting for the remove function. 3. If the continue is not taken, then host is added to a list, that has a lifetime beyond the end of the for_each_available_child_of_node loop body. Thus, of_node_get is needed on child, which is referenced by host. A corresponding of_node_put is needed in the remove function. Signed-off-by: Julia Lawall <[email protected]> --- One could consider whether the of_node_get should be on host->of_node, which looks more similar to the thing that is stored in the list. I used child, to be more similar to the of_node_put in the same function. drivers/mtd/nand/brcmnand/brcmnand.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/drivers/mtd/nand/brcmnand/brcmnand.c b/drivers/mtd/nand/brcmnand/brcmnand.c index 2a437c7..b0cb55d 100644 --- a/drivers/mtd/nand/brcmnand/brcmnand.c +++ b/drivers/mtd/nand/brcmnand/brcmnand.c @@ -2237,16 +2237,20 @@ int brcmnand_probe(struct platform_device *pdev, struct brcmnand_soc *soc) struct brcmnand_host *host; host = devm_kzalloc(dev, sizeof(*host), GFP_KERNEL); - if (!host) + if (!host) { + of_node_put(child); return -ENOMEM; + } host->pdev = pdev; host->ctrl = ctrl; host->of_node = child; ret = brcmnand_init_cs(host); - if (ret) + if (ret) { + devm_kfree(dev, host); continue; /* Try all chip-selects */ - + } + of_node_get(child); list_add_tail(&host->node, &ctrl->host_list); } } @@ -2264,8 +2268,10 @@ int brcmnand_remove(struct platform_device *pdev) struct brcmnand_controller *ctrl = dev_get_drvdata(&pdev->dev); struct brcmnand_host *host; - list_for_each_entry(host, &ctrl->host_list, node) + list_for_each_entry(host, &ctrl->host_list, node) { + of_node_put(host->of_node); nand_release(&host->mtd); + } dev_set_drvdata(&pdev->dev, NULL); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
