https://github.com/torvalds/linux
Revision 67f269b37f9b4d52c5e7f97acea26c0852e9b8a1 authored by Jason Gunthorpe on 16 April 2019, 11:07:28 UTC, committed by Jason Gunthorpe on 24 April 2019, 16:32:25 UTC
When this code was consolidated the intention was that the VMA would
become backed by anonymous zero pages after the zap_vma_pte - however this
very subtly relied on setting the vm_ops = NULL and clearing the VM_SHARED
bits to transform the VMA into an anonymous VMA. Since the vm_ops was
removed this broke.
Now userspace gets a SIGBUS if it touches the vma after disassociation.
Instead of converting the VMA to anonymous provide a fault handler that
puts a zero'd page into the VMA when user-space touches it after
disassociation.
Cc: stable@vger.kernel.org
Suggested-by: Andrea Arcangeli <aarcange@redhat.com>
Fixes: 5f9794dc94f5 ("RDMA/ucontext: Add a core API for mmaping driver IO memory")
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
1 parent d5e560d
Tip revision: 67f269b37f9b4d52c5e7f97acea26c0852e9b8a1 authored by Jason Gunthorpe on 16 April 2019, 11:07:28 UTC
RDMA/ucontext: Fix regression with disassociate
RDMA/ucontext: Fix regression with disassociate
Tip revision: 67f269b
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| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
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| .clang-format | -rw-r--r-- | 14.6 KB |
| .cocciconfig | -rw-r--r-- | 59 bytes |
| .get_maintainer.ignore | -rw-r--r-- | 31 bytes |
| .gitattributes | -rw-r--r-- | 30 bytes |
| .gitignore | -rw-r--r-- | 1.5 KB |
| .mailmap | -rw-r--r-- | 11.0 KB |
| COPYING | -rw-r--r-- | 423 bytes |
| CREDITS | -rw-r--r-- | 96.9 KB |
| Kbuild | -rw-r--r-- | 1.5 KB |
| Kconfig | -rw-r--r-- | 563 bytes |
| MAINTAINERS | -rw-r--r-- | 491.4 KB |
| Makefile | -rw-r--r-- | 58.3 KB |
| README | -rw-r--r-- | 727 bytes |
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