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| author | Sascha Hauer <s.hauer@pengutronix.de> | 2012-12-12 14:55:40 +0100 |
|---|---|---|
| committer | Sascha Hauer <s.hauer@pengutronix.de> | 2012-12-12 15:04:27 +0100 |
| commit | 1a9e93cc81dbae55743c0dafae4bd6ac8241e8a3 (patch) | |
| tree | 14b39c5b2124e25e4903e497a1bca7867e73d456 /drivers/w1 | |
| parent | c7c9c88cc2acbba29b8cbc9ddcf320857c93134c (diff) | |
| download | barebox-1a9e93cc81dbae55743c0dafae4bd6ac8241e8a3.tar.gz barebox-1a9e93cc81dbae55743c0dafae4bd6ac8241e8a3.tar.xz | |
drivers/base: fix corrupt device tree
dev_add_child is a very unsafe function. If called multiple times
it allows setting the same device to different parents thus corrupting
the siblings list. This happens regularly since:
| commit c2e568d19c5c34a05a1002d25280bf113b72b752
| Author: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
| Date: Sat Nov 3 16:11:05 2012 +0100
|
| bus: add bus device
|
| automatically add it as parent of any bus device if none already specified
|
| we have now a nice output per bus
If for example a FATfs is mounted this nice output per bus often ends with:
> `---- fat0
> `---- 0
> `---- 0x86f0000087020031-0x86f000410df27124: /dev/<NULL>
> `---- sram00
> `---- 0x00000000-0xffffffffffffffff: /dev/<NULL>
> `---- 0x00000000-0xffffffffffffffff: /dev/<NULL>
> unable to handle NULL pointer dereference at address 0x0000000c
> pc : [<87f08a20>] lr : [<87f08a04>]
> sp : 86eff8c0 ip : 87f3fbde fp : ffffffff
> r10: ffffffff r9 : 00000000 r8 : 00000003
> r7 : 86f075b8 r6 : 00000002 r5 : ffffffec r4 : 86f07544
> r3 : 00000000 r2 : 43f900b4 r1 : 00000020 r0 : 00000005
> Flags: Nzcv IRQs off FIQs off Mode SVC_32
> [<87f08a20>] (do_devinfo_subtree+0x90/0x130) from [<87f08a90>] (do_devinfo_subtree+0x100/0x130)
>
> [<87f3e070>] (unwind_backtrace+0x0/0x90) from [<87f28514>] (panic+0x28/0x3c)
> [<87f28514>] (panic+0x28/0x3c) from [<87f3e4b8>] (do_exception+0x10/0x14)
> [<87f3e4b8>] (do_exception+0x10/0x14) from [<87f3e544>] (do_data_abort+0x2c/0x38)
> [<87f3e544>] (do_data_abort+0x2c/0x38) from [<87f3e268>] (data_abort+0x48/0x60)
This patch fixes this by adding a device to its parents children list in
register_device so that dev_add_child is no longer needed. This function
is removed from the tree. Now callers of register_device have to clearly
set the parent *before* registering a device.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Reported-by: Jan Lübbe <jlu@pengutronix.de>
Diffstat (limited to 'drivers/w1')
| -rw-r--r-- | drivers/w1/w1.c | 4 |
1 files changed, 0 insertions, 4 deletions
diff --git a/drivers/w1/w1.c b/drivers/w1/w1.c index 11b8320d12..d2f94c938d 100644 --- a/drivers/w1/w1.c +++ b/drivers/w1/w1.c @@ -413,7 +413,6 @@ static int w1_device_register(struct w1_bus *bus, struct w1_device *dev) dev->bus = bus; dev->dev.parent = &bus->dev; - dev_add_child(dev->dev.parent, &dev->dev); ret = register_device(&dev->dev); if (ret) @@ -600,10 +599,7 @@ int w1_bus_register(struct w1_bus *bus) strcpy(bus->dev.name, "w1_bus"); bus->dev.id = DEVICE_ID_DYNAMIC; - bus->dev.parent = bus->parent; - if (bus->parent) - dev_add_child(bus->parent, &bus->dev); ret = register_device(&bus->dev); if (ret) |