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author | Sascha Hauer <s.hauer@pengutronix.de> | 2012-12-12 14:55:40 +0100 |
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committer | Sascha Hauer <s.hauer@pengutronix.de> | 2012-12-12 15:04:27 +0100 |
commit | 1a9e93cc81dbae55743c0dafae4bd6ac8241e8a3 (patch) | |
tree | 14b39c5b2124e25e4903e497a1bca7867e73d456 /drivers/spi/spi.c | |
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/spi/spi.c')
-rw-r--r-- | drivers/spi/spi.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 6a5bd6d2b8..d58b6646b5 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -81,7 +81,7 @@ struct spi_device *spi_new_device(struct spi_master *master, proxy->dev.id = DEVICE_ID_DYNAMIC; proxy->dev.type_data = proxy; proxy->dev.device_node = chip->device_node; - dev_add_child(master->dev, &proxy->dev); + proxy->dev.parent = master->dev; /* drivers may modify this initial i/o setup */ status = master->setup(proxy); |