From cdeb2ba99cb333f7729cd5784ea2de00e265f22f Mon Sep 17 00:00:00 2001 From: Bin Meng Date: Mon, 24 Aug 2015 01:14:02 -0700 Subject: [PATCH] dm: core: Fix code reentrancy issue in device_probe_child() The device might have already been probed during the call to device_probe() on its parent device (e.g. PCI bridge devices). In its parent device's probe routine, it might probe all of its child devices via device_probe() thus the codes reenter device_probe_child(). To support code reentrancy, test these allocated memory against NULL to avoid memory leak, and return to the caller if dev->flags has DM_FLAG_ACTIVATED set after device_probe() returns, so that we don't mess up the device. Signed-off-by: Bin Meng Acked-by: Simon Glass --- drivers/core/device.c | 19 ++++++++++++++----- 1 file changed, 14 insertions(+), 5 deletions(-) diff --git a/drivers/core/device.c b/drivers/core/device.c index e23a8725e7..a31e25f6b5 100644 --- a/drivers/core/device.c +++ b/drivers/core/device.c @@ -226,17 +226,17 @@ int device_probe_child(struct udevice *dev, void *parent_priv) drv = dev->driver; assert(drv); - /* Allocate private data if requested */ - if (drv->priv_auto_alloc_size) { + /* Allocate private data if requested and not reentered */ + if (drv->priv_auto_alloc_size && !dev->priv) { dev->priv = alloc_priv(drv->priv_auto_alloc_size, drv->flags); if (!dev->priv) { ret = -ENOMEM; goto fail; } } - /* Allocate private data if requested */ + /* Allocate private data if requested and not reentered */ size = dev->uclass->uc_drv->per_device_auto_alloc_size; - if (size) { + if (size && !dev->uclass_priv) { dev->uclass_priv = calloc(1, size); if (!dev->uclass_priv) { ret = -ENOMEM; @@ -251,7 +251,7 @@ int device_probe_child(struct udevice *dev, void *parent_priv) size = dev->parent->uclass->uc_drv-> per_child_auto_alloc_size; } - if (size) { + if (size && !dev->parent_priv) { dev->parent_priv = alloc_priv(size, drv->flags); if (!dev->parent_priv) { ret = -ENOMEM; @@ -264,6 +264,15 @@ int device_probe_child(struct udevice *dev, void *parent_priv) ret = device_probe(dev->parent); if (ret) goto fail; + + /* + * The device might have already been probed during + * the call to device_probe() on its parent device + * (e.g. PCI bridge devices). Test the flags again + * so that we don't mess up the device. + */ + if (dev->flags & DM_FLAG_ACTIVATED) + return 0; } seq = uclass_resolve_seq(dev); -- 2.25.1