s390/mm,gmap: segment mapping race

Browse source

The gmap_map_segment function creates a special invalid segment table
entry with the address of the requested target location in the process
address space. The first access will create the connection between the
gmap segment table and the target page table of the main process.
If two threads do this concurrently both will walk the page tables and
allocate a gmap_rmap structure for the same segment table entry.
To avoid the race recheck the segment table entry after taking to page
table lock.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

...

This commit is contained in:

Martin Schwidefsky 2013-04-16 13:37:46 +02:00

parent c5034945ce

commit ab8e523586

1 changed files with 91 additions and 69 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

160

arch/s390/mm/pgtable.c

View file