um: Fix kernel mode fault condition
authorRichard Weinberger <richard@nod.at>
Sun, 9 Aug 2015 20:26:33 +0000 (22:26 +0200)
committerRichard Weinberger <richard@nod.at>
Mon, 19 Oct 2015 20:53:37 +0000 (22:53 +0200)
commit56b88a3bf97a39d3f4f010509917b76a865a6dc8
tree408b519405bd8545f8da4102ac120db58d2a1f3e
parent6b1873371cea13036171d03a7c1e3e59158b4505
um: Fix kernel mode fault condition

We have to exclude memory locations <= PAGE_SIZE from
the condition and let the kernel mode fault path catch it.
Otherwise a kernel NULL pointer exception will be reported
as a kernel user space access.

Fixes: d2313084e2c (um: Catch unprotected user memory access)
Signed-off-by: Richard Weinberger <richard@nod.at>
arch/um/kernel/trap.c